Patent Grant
10125974
The present invention relates to circulating fluidized-beds integrating a multifunctional inertia-gravity separator with a plurality of models of boiler main bodies, including hot-water boilers, steam boilers, phase-transformation hot-water boilers, heat and power cogeneration boilers and power plant boilers; particularly relates to an ultra-large circulating fluidized-bed power plant boiler and a large-scale phase-transformation hot-water boiler for centralized heating; and relates to the energy-saving and emission-reducing improvement of various circulating fluidized-bed boilers, pulverized coal boilers and grate-firing chain boilers.
Due to its advantages of wide fuel adaptability, high combustion efficiency, low nitrogen oxide emission, efficient desulfuration, excellent load regulation performance and the like, the circulating fluidized-bed boiler combustion technology is universally recognized as the most promising clean, energy-saving and environmentally-friendly combustion technology. The energy-saving and environmentally-friendly industry ranks in the first among seven strategic emerging industries in China, and the fluidized-bed boiler is listed first in the “twelfth-five” energy-saving and environmentally-friendly industry development planning of China. From the perspective of China's manufacturing industry, this product belongs to the traditional industry; while from the perspective of energy conversation and environmental friendliness, this product belongs to a novel strategic industry.
As one important thermal power equipment in the national economy, boilers are widely applied in electric power, machinery, metallurgy, chemical industry, spinning, papermaking, food, industrial and civil heating and other industries, and are known as one industry eternally coexistent with human beings.
Circulating fluidized-bed boilers not only have the unique advantages of high combustion efficiency, high desulfuration and denitrification efficiency, low cost, wide coal adaptability, combustibility for low calorific value coal and low-grade coal and the like, but also have unique advantages in biomass power generation and municipal garbage power generation. Apparently, the circulating fluidized-bed boilers have the advantages of not only the conventional fire coal, but also the new energy resource industry. If there is a large breakthrough on this technology to adapt to the wide popularization in the market, the circulating fluidized-bed boilers will certainly have a significant influence on the energy conversation, consumption reduction and emission reduction in China or even in the whole world.
As a core component of a circulating fluidized-bed boiler, a circulating fluidized-bed gas-solid separator is known the heart of the boiler and mainly functions as separating a large amount of high-temperature solid particles from airflow, and then feeding the solid particles back to the hearth to maintain a fast fluidization state within the combustion chamber and ensure multiple times of circulation, repeated combustion and reaction of fuel and a desulfurizer, so as to achieve ideal combustion efficiency and desulfurization/denitrification efficiency. Accordingly, for a circulating fluidized-bed boiler, the performance of the gas-solid separator directly influences the running of this boiler. Generally, the form, operating effect and service life of a separator are regarded as marks of a circulating fluidized-bed boiler, In a sense, the performance of a circulating fluidized-bed boiler depends on the performance of the separator, and the development of the circulating fluidized-bed technology also depends on the development of the separation technology. At present, the most prevailing circulating fluidized-bed separators having the highest share in the Chinese market are high-temperature cyclone separators made of refractory material. However, such high-temperature cyclone separators mainly have the disadvantages of high resource consumption, many performance shortcomings, high wind velocity and large resistance at the tangential inlet, and high power consumption of the draft fan; and have the following serious shortcomings: due to the high-velocity reverse flowing of gas and solid from the output of the hearth to the storage bin, a large amount of ash is carried in the airflow; the initial emission concentration of fume is very high, so the wear-resistant process to the fume inlet on the convection heating face is made completed and the convection heating face is likely to be worn and to have dust deposited thereon; the service life of the boiler is shortened, the thermal resistance is increased, the heat transfer coefficient is decreased, and the deashing strength is weakened. In some cases, to solve these shortcomings, intermediate- and low-temperature separation modes are employed. Although these two separation modes can improve the wear, they have the following largest disadvantage that fine particles and ash carried by airflow from the outlet of the hearth can not continue to combust so that the content of carbon in ash is high. In some cases, to solve this disadvantage to reduce the flow velocity and improve the fuel fineness and to improve the main efficiency parameters by the incremental cost of energy consumption, a high-temperature cyclone separation mode is employed. Although this separation mode has the advantage of reducing the content of carbon in ash, the high original emission concentration of fume is still not solved, and the use of wear-resistant measures at the inlet end of the convection heating face is complicated and still has hazards.
As a dry cyclone separator utilizes a large amount of wear-resistant and thermal insulating material, both the raw material cost and the manufacturing and installation cost of the separator are increased, large thermal inertia and thermal loss are also caused, Such a separator is likely to suffer coke formation at a high temperature, and the boiler is slow to start and stop.
For various inertia separators ever popular in China, by changing the flow direction of fume to collide with an object, separation elements in various intensive structure forms are provided in a fume passage, For example, S-shaped planar flow separators, shutter type separators and groove type separators are all inertia separators. Such a gas-solid separation mode not only artificially increases the flowing resistance and the power consumption, but also reduces the separation efficiency and makes a large amount of ash in the airflow, and the separation elements are likely to be deformed and damaged. Therefore, circulating fluidized-bed boilers using various inertia separators ever popular in China have been gradually driven out of the market.
For circular and square steam/water-cooling cyclone separators currently popular in Europe and America, the amount of wear-resistant material is reduced to solve the shortcomings of large thermal inertia and thermal loss so that the boilers are less likely to be coked and quick to start and stop. but there are still shortcomings of high power consumption of the draft fan and high original emission concentration both resulted from high wind velocity large resistance, serious elutriation and entrainment of ash. As the circular steam-cooling cyclone separators have high steel consumption, complicated manufacturing process and thus high price, it is difficult for customers to use such circular steam-cooling cyclone separators, thereby resulting in very low market share. Although square steam-cooling cyclone separators have low steel consumption and superior manufacturing process, the separation efficiency and stability of the square steam-cooling cyclone separators are lower than those of the circular steam-cooling cyclone separators.
In the present invention, by applying, a theory of inertia separation of dust due to sudden large-angle change of flowing direction and collision with tube bundles, a theory of velocity reduction and gravity settlement due to sudden capacity expansion, a theory that the fume may settle naturally when the flow velocity of the fume is 3 m to 5 m, and a theory that both a better heat transfer coefficient and a better economic velocity may be realized when the flow velocity of the fume is ≤5.10 m, all to inertia-gravity separators, thereby bringing the multifunctional performance of a water-cooling inertia-gravity separator into full play. Particularly, the organic combination of inertia separation and gravity separation effectively strengthens the gravity settlement effect and may realize the effective separation of fine particles having a specific gravity higher than that of air from a large amount of ash.
The gas-solid separator in the circulating fluidized-bed boiler as disclosed in Patent No. ZL201110036996.8 and Application No. 201110383051,3 has many advantages in comparison to a high-temperature cyclone separator, for example, low flowing resistance, saving of power consumption of the draft fan, saving of wear-resistant high-temperature material due to the structure of the water-cooling separator. However, due to the misunderstanding of the original conception and the theoretical method, the structure has serious shortcomings. For example, the wear-resistant communicating tube and the equalizing and separating tube bundles at the inlet and outlet of a turning passage occupy the cross-section of the upward and downward flues and increase the volume, and the complicated process influences the operating stability of the separator. As the rear wall of the hearth and the front wall of the shaft absolutely may be used as the common wall of the front and rear ways of the separator, the tube bundle in the vertical segment of the front and rear was of the separator is unnecessary and has negative effects. If the fume velocity of the upward flue of the separator is 3 M, the volume will certainly be increased greatly, so that it is inappropriate for development towards large scale. A secondary low-temperature downward-exhaust cyclone separator has the following shortcomings that: first, the flowing resistance is high; second, the separation efficiency is low; and third, it is unable to realize automatic discharge of deposited ash from the rear of the ventilator.
As the front and rear walls of the separator provided by the present invention share the same walls with the rear wall of the hearth and the front wall of the shaft, all the shortcomings are eliminated. The fume velocity of the downward flue of the primary high-temperature water-cooling inertia gravity separator may be 5 M to 50 M, and the fume velocity of the outlet of the downward flue may be 10 M to 15 M or 20 M, which not only is advantageous for the enhancement of heat transfer and the prevention of the volume increase of the boiler, but also may effectively increase the multiple of sudden capacity expansion and velocity reduction and reduce the fume velocity at the inlet end of the upward flue. The fume velocity at the inlet end of the upward flue is ≤3 M or 5 M. A single-stage or multi-stage high-temperature over-heater is disposed at a distance away from the inlet end of the upward flue, and the fume velocity is ≤10 M, so that the heat transfer may be enhanced and both the flowing resistance and the power consumption of the draft fan may be reduced due to the economic flow velocity. A space from the lower end of the high-temperature over-heater to the upper end of the storage bin is not only a large capacity-capacity-expanding space solid settlement chamber but also a burn-out chamber where combustibles are allowed to be fully burned, so that the primary high-temperature water-cooling inertia-gravity separator may naturally realize multiple functions of efficient gas-solid separation, sufficient combustion and efficient radiative-convective heat transfer. The sudden capacity expansion and velocity reduction at the output of the downward flue is advantageous for gas-solid separation and radiative heat transfer, and the low flow velocity at the inlet end of the upward flue is advantageous for the gravity settlement of fine particles and ash into the storage bin so as to reduce airflow entrainment. The high-temperature over-heater disposed at a vertical segment of the upward flue is advantageous for efficient convective heat transfer, and the high-temperature over-heater disposed on the upward flue, as a convection heating face and also a gas-solid separation element, is advantageous for the collision of fine particles and ash thereto to realize efficient convective heat transfer and inertia separation. Particularly, as the back-feeding valve is directly communicated to the hearth, the height occupied by the back-feeding leg is omitted, so that an effective space is vacated, it is advantages for the reduction of the height of the boiler body or the multifunctional performance of the primary high-temperature water-cooling inertia-gravity separator; and the material is quicker and smoother to be back-fed to the hearth. The principle of the secondary low-temperature inertia-gravity water-cooling separator is the same as the primary separation. The ash is forced to directly fall to the bottom of the storage bin by the guiding fume directly-raising storage bin spacer, so that an ultra-high gas-solid separation efficiency, an ultra-low original emission concentration of fume and a small size of the boiler are ensured. 27 solutions provided by the present invention are suitable for enterprises having different boiler model, different coal type, different water quality, different customer tolerance and different construction equipment, and may be combined and integrated with each other for secondary innovation.
An object of the present invention is to eliminate all shortcomings of the present circulating fluidized-bed boilers and provide a circulating fluidized-bed boiler integrating a multifunctional inertia-gravity separator with multiple novel boiler bodies, with the following revolutionary advantages: in the aspects of greatly reducing resource consumption and original emission concentration of boiler fume, eliminating the wear of a convection heating face and comprehensively improving boiler performance of the present invention, the structure style and separation mode of the present circulating fluidized-bed boiler cyclone separator in China and abroad have a large gap in comparison to the present invention and are infeasible.
The revolutionary advantages formed by 18 details of the multifunctional inertia-gravity separator provided by the present invention are as follows:
1. Ultra-low resistance saves the power consumption of the draft fan. This is because the fume flow velocity of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator is lower than the flow velocity of the cyclone separator.
2. Ultra-low energy consumption saves raw material. This may be indicated by saving by 90% of the wear-resistant material, by 50-80% of thermal insulating material, and by 100% of the metal material of a non-heating surface heat-resistant steel ventilator, a heat-resistant steel mesh and a steel cylinder of a dry high-temperature cyclone separator: and saving by 30-60% of steel and wear-resistant material and by 50-70% of thermal insulating material of a steam-cooling circular cyclone separator.
3. Ultra-low dust emission saves the investment in dust removing equipment and cost in maintenance and replacement. This is because, the highest value of the original emission concentration of the boiler fume by two-stage separation may be <1800 mg/m3.
4. Ultra-high separation efficiency eliminates the wear to the convection heating face and prolongs the service life of the whole boiler. This is because, the solid is directly conveyed to the storage bin by airflow under the action of a guiding fume directly-raising storage bin water-cooling wall, high concentration of gas and solid from the outlet of the hearth comes down with a sharp turn of 180° and then flows in a same direction to directly to the large capacity-expansion space to the storage bin; and, the sharply turned centrifugal force and drag force, blowing force of the airflow, the gravity of the solid and the ground gravitation may allow the velocity of the solid falling from up to down to be higher that the velocity of the airflow, so that the large capacity expansion of the high velocity outlet of the downward flue and the low velocity inlet of the upward flue create a condition that the separable specific gravity is higher the fine particles and ash in air.
5. Ultra-high combustion efficiency reduces the carbon content of the combustible. This may be indicated by the efficiency of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator and multi-stage separation, particularly the downward and upward flues, the turning passage and the large capacity-capacity-expanding space increasing the burn-out time of the combustible at the height of nearly the hearth in the boiler.
6. The advantage that the ultra-high separation efficiency of the primary water-cooling high-temperature separation may allow the shaft flue and convection heating face of a low-pressure steam and large-scale heating boiler to employ a shell shaft thread flue convection heating face and allow for shaft flue sealing and convective heat transfer strength is irreplaceable.
7. Two shortcomings of high-temperature coking due to low an ash fusion point and high-temperature corrosion of the heater during biomass and urban garbage power generation may be solved. This may be indicated by the radiative heat transfer and burn-out of the downward and upward flues and the large capacity expansion space of the full-water-cooling separator and the arrangement of the over-heater not in the separator.
8. The reduction of the carbon content of ash improves comprehensive energy efficiency. This may be indicated by the ultra-high consumption efficiency and the Ultra-low original fume emission.
9. Saving the maintenance cost of the separator improves comprehensive energy efficiency. This may be indicated by the water-cooling separator.
10. The reduction of heat low improves comprehensive energy efficiency. This may be indicated by the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator.
11. The boiler is started and stopped quickly and the separator is not coked. This may be indicated by the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator.
12. Single-stage and double-stage separation may replace the shortcoming of the wear and cost of maintenance and replacement of a buried pipe. This may be indicated by the scientific matching and adjusting of the dense phase zone temperature replaced buried pipe of the first-stage primary high-temperature inertia-gravity water-cooling separator and the secondary low-temperature water-cooling inertia-gravity separator.
13. The double-stage separation may replace the shortcoming of high high-pressure wind power consumption and difficult maintenance of an external heat exchanger: the secondary low-temperature inertia-gravity water-cooling separator may adjust the temperature of the dense phase zone, the heating surface of the primary high-temperature inertia-gravity water-cooling separator and the arrangement of the over-heater in the upward flue space of the primary high-temperature inertia-gravity water-cooling separator may be far larger than the heat transfer area of the external heat exchanger.
14. The bottleneck of uneconomical operation of the boiler <35 t may be solved. This may be indicated by the scientific design of dense and dilute phase zones, two structures partitioned by a equalizing, separating and heat storing device and the back-feeding valve directly being communicated to the hearth, the downward and upward flues and the large capacity expansion space and the like.
15. The size of the boiler may be reduced and the steel may be saved. This may be indicated by reducing the height of the boiler body, reducing the thickness of the refractory and thermal insulating material and the weight of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator.
16. Multiple functions of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator realize efficient utilization of the resource space, This may be indicated by efficient gas-solid separation, sufficient burning and heat exchange of the capacity expansion space, efficient heat transfer of the heater of the upward flue, the disturbance to the material in the storage bin by airflow cleaning wall fume in the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator.
17. The full coverage of hot-water, steam industrial boilers and heat-power cogeneration, station boilers from minimum to maximum may be realized; and, the selections of manufacturing enterprises of different coal types, different water qualities, different models of boilers, different areas, different custom demands, different customer bearing capacities and different construction installation equipment conditions may be adapted.
18. The advantage of competitive large-scale and ultra-large-scale coal powder station boilers may be realized. This may be indicated by the integral structure of the boiler, ultra-low resistance, ultra-low energy consumption, ultra-low fume emission, ultra-high separation efficiency and combustion efficiency, wide boiler coal adaptability and burning low-grade coal, high desulfurization and denitrification efficiency, low cost, and low raw coal smashing cost.
The meaning of the low resource consumption of the present invention is not inferior to any energy resource development. The basis of the low resource consumption of the present invention is as follows: large and medium-scale fluidized-bed boilers in the Chinese market at present are a plurality of dry high-temperature cyclone separators. The larger the boiler is, the greater the number of separators is and the larger the diameter is. Each separator cylinder is a wear-resistant and heat insulating layer having a thickness of 350 mm constructed in a heat-resistant steel mesh in a steel cylinder. The fume outlet of each separator is required to have a heat-resistance steel ventilator, where the wind velocity of the inlet of the ventilator is 20 m and the wind velocity of the outlet is 30 m. As a high flow velocity is likely to carry with solid particles of a certain grain size, the inlet of the convection heating face needs to be performed with wear-resistant processing. If any carelessness, it is difficult to avoid the wear of the heating surface.
In the present invention, regardless of the size of the boiler, the cylinder section of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator is of a rectangular structure. Two largest wall surfaces among four wall surfaces of the rectangular structure of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator completely are a rear wall of the hearth and a front wall of the shaft. As the transverse width of the boiler is about 2 times of the longitudinal depth, the two wall surfaces are heated on double surfaces without thermal insulating material, so that it is only required to perform heat insulation to two side walls of the rectangular separator in the present invention. Because the presence of the water-cooling wall may reduce the heat insulating thickness, the length of a single wide wall of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator is approximately equal to the diameter of one cyclone separator plus a distance between inlet and outlet tube sections. The perimeter of one cyclone separator is equal to or larger than the length of the two side walls of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separators. When the fume velocity of the downward flue of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator is 5 to 20 M, it is only required to provide wear resistance at one third of the rectangular structure, where the thickness of the wear resistance is 30 mm to 50 mm, For a boiler having four dry cyclone separators, the rectangular structure of the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator provided by the present invention only requires thermal insulating material of half a cyclone separator and wear-resistant material of one third of one cyclone separator. When the velocity of the downward flue is designed as ≤5 m, wear resistance or local wear resistance may be not employed.
The revolutionary advantages of multiple models of boilers of the present invention are as follows:
1. The single horizontal drum, full-membrane-wall hearth, full-water-cooling separator, full-membrane-wall shaft, full-water-cooling ceiling and good tightness and heat transfer performance of the boiler may simplify the thermal expansion design and installation process, reduce maintenance cost and prolong the service life of the boiler.
2. Due to single or double vertical and horizontal drums, the structure of the boiler body is in various forms, and more than one hundred series and hundreds and even thousands of types may be developed to adapt to the selections of enterprises of different coal types, different water qualities, different models of boilers, different areas, different custom demands, different customer bearing capacities and different construction installation equipment conditions; and, the full coverage of hot-water, steam industrial boilers and heat-power cogeneration, power plant boilers from minimum to maximum may be realized.
3. For the forced-circulating hot-water boiler having double horizontal drums, the full-water-cooling hearth, the full-water-cooling separator, the full-water-cooling ceiling, and fume to return up and down for 8 times, so that the fume route is long, the heat transfer effect is good, the multi-stage separation of gas, solid and ash greatly reduces the ash on the convector heating surface.
4. Shell shaft: the shaft is sealed and has no air leakage, so the fume emission loss is reduced; and, the shaft never needs to be maintained, so the maintenance cost is greatly saved, and the steel frame and refractory material of the shaft are saved.
5. The shell thread fume tube convection heating face is vertically designed and installed, so the convection heating face has efficient heat transfer, no ash deposition and stable heat efficiency.
6. The single vertical drum, the full-water-cooling ceiling and the drum are supported by water-cooling wall tubes on the front and rear sides, the process is advanced, and the steel frame is omitted.
7. Upper portions of all the single vertical drum, the vertical upper central header, and the equalizing, separating and heat storing device disposed on the upper part of the hearth are integrated together, and lower portions thereof are also integrated together, so ≤35 ton of steam boiler may realize separate manufacture fields and separate assembling in a factory, so that the quality and efficiency of manufacturing and installation may be greatly improved, combustion is enhanced, internal and external gas-solid separation performance is improved, and various shortcomings caused by the reduction of the height of the boiler body are solved.
8. The phase-transformation heat-exchange hot-water boiler for the fluidized-bed having vertical drums may be kept from scaling, oxygen corrosion, pollution discharge, softened water equipment and deoxygenization equipment, and is an irreplaceable product having the advantages of high efficiency, energy conversation, waver conversation, consumption reduction and emission reduction in the hot-water and heat supply field.
9. For the phase-transformation heat-exchange hot-water boiler for the fluidized-bed having vertical drums, the boiler body forms a framework itself and supports by itself, the structure is compact, the integrality is high, and the steel frame is greatly omitted; the drum header bundles are vertically and horizontally communicated to each other, so the boiler water is circulated and uniformly descended and ascended for automatic adjustment, so that the natural circulation is safer and more reliable; the perfect matching of the heat exchanger and the boiler makes the advantages of the large-scale phase-transformation hot-water boiler more prominent.
10. For the vertical drum fluidized-bed phase-transformation hot-water boiler, the full-water-cooling wall structure and process are advanced, and fume is separated initially through multiple loops in the boiler, so that original emission concentration of fume is greatly reduced; the ash on the heating area is greatly reduced, and both thermal resistance and flowing resistance are reduced: fume are circulated for five cycles in the boiler, and the convection bundles are vertically arranged for transverse washing, so that the fume flow path is long, the heat exchange effect is excellent and the thermal efficiency is high.
To solve the technical shortcomings in the prior art, the present invention provides a circulating fluidized bend boiler with a plurality of models of boilers, which comprehensively improves the boiler performance, drastically realizes the energy conversation, consumption reduction and emission reduction and has advanced process.
A fluidized-bed boiler integrating a multifunctional inertia-gravity separator and a plurality of models of boilers is provided, a water-cooling wall or spacer of a guide gas-solid phase fling storage bin is provided at a fume inlet section of the two-stage inertia-gravity separators, so as to form the property of directly conveying solid to a storage bin by airflow, so that the gas and solid are forced to vertically come down to directly to a large capacity expansion space and further to the storage bin. Front walls of both the storage bin and the dipleg share a same or different wall with the rear wall of a hearth. The front end of a back-feeding valve is directly communicated to the hearth to make the circulation of material faster and smoother, The two-stage inertia-gravity separators realize velocity reduction by sudden large-angle change and sudden large capacity expansion in terms of the fume flowing direction. By correctly mastering the different direction, different velocity and different angle, the efficient gas-solid separation, efficient heat transfer and sufficient combustion of the primary high-temperature water-cooling inertia-gravity separator are realized, the ash separation and returning of the secondary low-temperature inertia-gravity water-cooling separator, the reduction of content of carbon in ash, the ultra-low original fume emission of the boiler, and temperature adjustment of the dense-phase zone are achieved.
Beneficial Effects
According to the method for improving the efficiency of desulfurization and denitrfication and reducing emission of other pollutants provided by the present invention, there are three sections within the hearth for three-stage air supply, i.e., a boiling combustion section from an air distribution plate to the upper end of a transition section, a suspending combustion section from the upper end of the transition section to the middle upper part of the hearth, and a high-temperature combustion section at the upper part of the hearth. The two sections in the middle lower part, with a temperature kept at about 50° C.; and the third section in the middle upper part provides for three-stage air supply, and the temperature inside a large capacity-capacity-expanding space from the third section to the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator is kept at about 950° C.
Primary high-temperature water-cooling inertia-gravity separator: a downward flue and an upward flue, a turning passage, a large capacity-capacity-expanding space (burn-out chamber) and a lower storage bin, which are made of membrane water-cooling walls or water-cooling walls and refractory material in a sealed manner, are disposed in a space from the rear wall of the hearth to the front wall of the shaft. Different fume velocities are respectively defined with respect to the different flowing segments of the downward flue, the upward flue, the turning passage and the large capacity-capacity-expanding space (burn-out chamber). Specifically, the fume velocity at the outlet end of the downward flue is increased, the fume velocity at the inlet end of the downward flue is decreased, the magnification of sudden expansion and velocity reduction into the large capacity-capacity-expanding space is increased, the compact inertia of gas and solid from high to s increased to enhance the efficient gas-solid separation, the continuous combustion of combustible material in the burn-out chamber (large capacity-capacity-expanding space) is reinforced, the fume velocity at the inlet segment of the upward flue is decreased to reduce the amount of ash in the airflow, the wear to the convectional heater face is completely eliminated, and the fume velocity of the segments above the inlet segment of the upward flue is increased to enhance the efficient heat transfer of the high-temperature airflow and high-temperature ash with the over-heater.
By the primary high-temperature water-cooling inertia-gravity separation under the effect of the water-cooling wall of the guiding gas-solid directly-raising storage bin, the fume is forced to descend sharply by 180° from the outlet of the hearth so that gas and solid flow in the same direction and directly raise to the large capacity-capacity-expanding space to the storage bin through the downward flue, so that highly concentrated solid particles are subject to a sharp centrifugal force and drag force first; the falling velocity of solid is made higher than that of airflow due to the vertical downward-flowing of both gas and solid in the same direction, the blowing of airflow, the weight of solid, the gravity and the vertical falling force from high to low; when the fume turns at a low velocity, fine particles having a specific gravity higher than that of air directly and quickly fall to the bottom of the storage bin; ash continuously burns in the large capacity-capacity-expanding space and burns out, smoke is subject to twice downward and upward turn-over inertia separation by 180° in the primary high-temperature water-cooling inertia-gravity separator, the secondary low-temperature inertia-gravity water-cooling separator or the single-stage high-temperature water-cooling inertia-gravity separator and a collision-type inertia separation with the over-heater within the upward flue and finally directly falls to the large capacity-capacity-expanding space for continuous combustion until burning out; and part, of the burn-out ash is settled in the storage bin, while the other part is carried away by airflow for convective heat-exchange with the over-heater and the coal economizer and then enters the secondary low-temperature inertia-gravity water-cooling separator for separation.
A secondary low-temperature inertia-gravity water-cooling separator is provided; the secondary low-temperature inertia-gravity water-cooling separator is disposed at the intersection of the lower ends of the plurality of over-heaters or coal economizers within the shaft of the membrane wall, the rear wall of the primary high-temperature water-cooling inertia-gravity separator and the oblique transition segment of the rear wall of the large capacity-capacity-expanding space, a part in the middle or slightly anterior of a space from the front wall to the rear wall of the secondary low-temperature inertia-gravity water-cooling separator is divided into a downward flue and an upward flue for the secondary low-temperature inertia-gravity water-cooling separator; under the effect of the guiding fume directly-raising storage bin spacer, the fume is forced to change by a large angle and to flow in the same direction to directly raise to the capacity-expanding space to the storage bin through the downward flue; ash having a specific gravity higher than that of air falls to the bottom of the storage bin through the large capacity-capacity-expanding space due to the blowing of airflow, the weight of ash and the gravity; once the ash falls to the bottom of the storage bin, due to the distance from the bottom of the storage bin to the upward flue of the secondary low-temperature inertia-gravity water-cooling separator, the ash carried away is limited even the fume velocity reaches the maximum economic velocity; the secondary separation is subject to one large oblique-degree change, one downward and upward turn-over separation by 180° and sudden expansion and velocity reduction for settlement due to gravity, so that the initial emission concentration of smoke from the boiler can be lower than the national environmental-protection standards for layer-burning chain boils.
In order to solve the technical problems of the known technologies, the present invention employs the following technical solutions. A fluidized-bed boiler integrating a multifunctional inertia-gravity separator and a plurality of models of boilers is provided, having a primary high-temperature water-cooling inertia-gravity separator: the rear wall of the membrane wall of the hearth and the front wall of the membrane wall of the shaft form the front wall and rear wall of this primary high-temperature water-cooling inertia-gravity separator, a space from the rear wall of the hearth to the front wall of the shaft is divided by the membrane wall of the guiding gas-solid directly-raising storage bin into an upward flue and a downward flue, the large capacity-capacity-expanding space (burn-out chamber) and its turning passage and the storage bin are at the lower ends at the outlet of the downward flue and the inlet of the upward flue, a high-temperature over-heater is mounted in the vertical segment of the upward flue so that this primary high-temperature water-cooling inertia-gravity separator naturally has multifunctional properties of efficient gas-solid separation, efficient heat transfer and complete combustion. The downward flue and the upward flue are resisted against and communicated to the lower part of the rear wall of the hearth in a sealed manner through the turning passage and through the storage bin, the dipleg and the back-feeding valve all sealed below the flues. The front upper part of this primary high-temperature water-cooling inertia-gravity separator is the fume inlet of the convection flue of one return stroke while the rear upper part thereof is the fume outlet. The four walls of this primary high-temperature water-cooling inertia-gravity separator are heated water-cooling walls integrally communicated to the hearth and the shaft. The front membrane wall and rear membrane wall of primary high-temperature water-cooling inertia-gravity separator and the membrane wall of the guiding gas-solid directly-raising storage bin are in low circulation ratio, and are all exposed two-sided heating faces except for partial wear measures on the wall face of the downward flue. Thus, both the heated area and the heat exchange effect are increased, and 100% thermal insulating material may be saved for three wall faces. The upper ends of the membrane walls on two sides of this primary high-temperature water-cooling inertia-gravity separator are communicated to the upper vertical header while lower ends thereof are communicated to the lower vertical header, and the two sides of the primary high-temperature water-cooling inertia-gravity separator are sealed by thermal insulating material. A secondary low-temperature inertia-gravity water-cooling separator is disposed at the lower ends of the plurality of over-heaters or coal economizers within the shaft of the membrane wall. The front wall of the secondary low-temperature inertia-gravity water-cooling separator is completely the rear wall of the primary high-temperature water-cooling inertia-gravity separator and the oblique transition segment of the rear wall of the large capacity-capacity-expanding space, while the rear wall thereof is the rear wall of the shaft and the guiding fume up-down turn-over spacer. The part in the middle or slightly anterior of a space from the front wall to the rear wall of the secondary low-temperature inertia-gravity water-cooling separator is divided into a downward flue and an upward flue for the secondary low-temperature inertia-gravity water-cooling separator. The capacity-expanding space and the storage bin are disposed in a space from the rear outer wall of the primary storage bin to the front outer wall of the shaft. The guiding fume directly-raising storage bin spacer is highly obliquely disposed in the middle or slightly anterior of the front and rear walls, with its upper lower being sealed against the rear wall of the shaft, its lower end being far away from the capacity-expanding space by a certain distance, and its two side ends being sealed against the bilaterally symmetric membrane wall. The guiding fume up-down turn-over spacer is highly obliquely disposed to be parallel to the downward flue and the upward flue, with its lower end being sealed against the front wall of the expanding wall or far away from the front wall of the expanding wall by a certain distance to be sealed against the front wall of the shaft, its upper end being extended to the center or slightly anterior of the shaft, and its two sidewalls and rear wall thereof being sealed by thermal insulating material.
in which:
In order to further understand the contents, features and effects of the present invention, the following embodiments are exemplified and described below in detail end with reference to the accompanying drawings.
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A primary high-temperature water-cooling inertia-gravity separator is disposed in a space from the rear wall 4 of the hearth to the front wall 31 of the shaft. The front wall of the primary high-temperature water-cooling inertia-gravity separator is completely the rear wall 4 of the hearth, and the rear wall 31 of the primary high-temperature water-cooling inertia-gravity separator and the oblique transition segment 36 of the rear wall of the large capacity-capacity-expanding space share a wall with the front wall of the shaft. A guiding gas-solid directly-raising storage bin water-cooling wall 17 is disposed in the middle or slightly anterior or more anterior of a space between the front wall and the rear wall of the primary high-temperature water-cooling inertia-gravity separator and is divided into a downward flue 18 in the front side and an upward flue 32 in the back side, and the fume velocity of the downward flue and the upper flue 32, 18 are differently designed for different heights and different demands. The fume velocity at the outlet end of the downward flue 18 is increased and the fume velocity at the inlet end of the upward flue 32 is decreased, suitably less than or equal to 3 M. When a high-temperature over-heater 27 is arranged in the vertical segment of the upward flue 32, the guiding gas-solid directly-raising storage bin water-cooling wall 17 is arranged more anterior of the space between the front wall and the rear wall of the primary high-temperature water-cooling inertia-gravity separator. When no high-temperature over-heater 27 is arranged in the vertical segment of the upward flue 32, the guiding gas-solid directly-raising storage bin water-cooling wall 17 is arranged in the middle or slightly anterior of the space between the front wall and the rear wall of the primary high-temperature water-cooling inertia-gravity separator. The length of the oblique transition segment 36 upward bent and extended from the lower end of the tube bundle 31 on the rear wall of the primary high-temperature water-cooling inertia-gravity separator should meet the velocity of both the capacity-expanding space 15 and the turning passage 14, the part from the lower horizontal header 16 of the water-cooling wall backward to the tube bundle 31 on the rear wall of the primary high-temperature water-cooling inertia-gravity separator and downward to the upper end of the storage bin 9 is the capacity-capacity-expanding space, the part from the lower end of the lower horizontal header 16 of the water-cooling wall to the upper end of the storage bin 9 is the turning passage, and the velocity of the turning passage is less than or equal to 3 M. The most significant feature of this primary high-temperature water-cooling inertia-gravity separator is that the back-feeding valve 53 is directly communicated to the hearth 8 without any dipleg, which provides an effective space for the turning passage 14 and the large capacity-capacity-expanding space 15 to be beneficial for the gas-solid separation, sufficient combustion and efficient heat transfer, and makes the circulation of material faster and smoother. The upper end of the vertical segment of the tube of the guiding gas-solid directly-raising storage bin water-cooling wall 17 of this primary high-temperature water-cooling inertia-gravity separator is obliquely bent forward and upward to be radially communicated to the upper horizontal header 24 while the lower end of the vertical segment thereof is obliquely bent forward and downward to be communicated to the lower horizontal header 16 of the water-cooling wall. A part from the lower horizontal header 16 of the water-cooling wall to the cross-section of the rear wall 4 of the hearth forms a fume outlet of the downward flue. The front wall of the downward flue 18 of this primary high-temperature water-cooling inertia-gravity separator is the rear wall 4 of the hearth, the rear wall and ceiling thereof are the front wall and the oblique segment at the upper end of the guiding gas-solid directly-raising storage bin water-cooling wall 17, and the two sidewalls thereof are the bilaterally symmetric membrane wall 25. The upper end of the bilaterally symmetric membrane wall 25 is communicated to the bilaterally symmetric upper vertical four-in-one header 21, while the lower end thereof is communicated to the bilaterally symmetric lower vertical three-in-one header 13.
The front wall of the upward flue 31 of this primary high-temperature water-cooling inertia-gravity separator is the rear wall of the guiding gas-solid directly-raising storage bin water-cooling wall 17, the rear wall thereof is the rear wall 30 of the primary high-temperature water-cooling inertia-gravity separator, the ceiling thereof is the forward oblique segment at the upper end of the tube bundle 34 on the rear wall of the shaft, and the two sidewalls thereof share a wall with the downward flue. The fume outlet of the upward flue 32 is the gap between the communicating tubes 28. The upper ends of the communicating tubes 28 are communicated to the lower part of the upper horizontal header 26, while the lower ends thereof are communicated to the upper part of the upper horizontal header 29 on the rear wall of the primary high-temperature water-cooling inertia-gravity separator. The upper end of the tube bundle on the rear wall 31 of the primary high-temperature water-cooling inertia-gravity separator is communicated to the lower part of the upper horizontal header 29 on the rear wall of the primary high-temperature water-cooling inertia-gravity separator, the lower end of the vertical segment thereof is bent forward and obliquely extended to be communicated to the lower horizontal header 42 on the rear wall of the separator, and the forward bent and obliquely extended segment is the oblique transition segment 6 of the rear wall of the expanding wall.
The storage bin 9 of the primary high-temperature water-cooling inertia gravity separator is formed of one to more trapezoids which have a rectangular or square cross-section, a large top and a small bottom and which is eccentric forward The upper end of the front wall 11 of the storage bin is sealed against the rear wall 4 of the hearth, the upper end of the rear wall 11 of the storage bin is sealed against the lower horizontal header on the rear wall of the primary high-temperature water-cooling inertia-gravity separator, and the upper ends of the two outer sidewalls thereof are sealed against the bilaterally symmetric lower vertical three-in-one header 13, The lower ends of the front wall 11 and rear wall 10 of the storage bin are inward oblique and divided by the spacer 12 of the storage bin into one or more trapezoidal storage bins which have a rectangular or square cross-section, a large top and a small bottom and which is concentric or eccentric forward, The upper end of the storage bin is flushed with and communicated to the lower end of the turning passage, while the lower end thereof is communicated to the upper end of one or more diplegs in a sealed manner. The lower end of the dipleg 7 is communicated to the upper end of the back-feeding valve 54 in a sealed manner.
The back-feeding valve 53 of the primary high-temperature water-cooling inertia gravity separator is a minimum fluidizing U valve or J valve. The front end of the back-feeding valve 53 is communicated to the rear wall 4 of the hearth in a sealed manner, while the upper end thereof is communicated to the lower end of the dipleg 7 in a sealed manner.
The secondary low-temperature inertia-gravity water-cooling separator is disposed at the lower ends of the plurality of over-heaters or coal economizers within the shaft 33 of the membrane wall. The front wall of the secondary low-temperature inertia-gravity water-cooling separator is completely the rear wall 31 of the primary high-temperature water-cooling inertia gravity separator and the oblique transition segment 36 of the rear wall of the large capacity-capacity-expanding space, the rear wall thereof is the guiding fume up-down turn-over spacer 37 and the rear wall 34 of the shaft. A part in the middle or slightly anterior of a space from the front wall to the rear wall of the secondary low-temperature inertia-gravity water-cooling separator is divided by guiding fume up-down turn-over spacer 37 into a downward flue 37 and an upward flue 142 for the secondary low-temperature inertia-gravity water-cooling separator.
The large expanding turning passage 45 and the storage bin 49 are disposed in the space from the front outer wall of the front membrane wall 49 in the middle part or middle upper part or middle lower part of the shaft 32 to the rear outer wall of the primary storage bin 44, The guiding fume directly-raising storage bin spacer 37 is highly obliquely disposed in parallel in the middle or slight anterior of the space between the front wall and the rear wall of the shaft, with its upper end being sealed against the rear wall 34 of the shaft, its two side ends being sealed against the bilaterally symmetric membrane wall 25, and its lower end being far away from the large expanding turning passage 45 by a certain distance. The guiding fume up-down turn-over spacer 44 is highly obliquely disposed in parallel to the upward flue 142, with its lower end being sealed against the upper end of the rear wall 47 of the storage bin and its upper end being extended to the center or slight anterior of the shaft.
The storage bin 49 of the secondary low-temperature inertia-gravity water-cooling separator is divided by the front and rear walls 48, 47 and the spacer 46 into rectangular or square trapezoids having a large top and a small bottom, According to the size of the boiler, trapezoids need to be horizontally arrayed in an equal manner. The upper end of the rear wall of the storage bin is sealed against the lower end of the guiding fume up-down turn-over spacer 44, the upper end of the front wall thereof is horizontally sealed against the upper end of the dipleg of the primary high-temperature water-cooling inertia gravity separator or any height of the rear wall 10 of the storage bin, the lower end thereof is communicated to the upper end of the dipleg 50 in a sealed manner. The lower end of the dipleg 50 is communicated to the secondary back-feeding device 52 in a sealed manner.
The primary inertia-gravity separation process in this embodiment is as follows. Fluidized-bed combustion means combustion of the bed material in the fluidized state. The fuels may be fossil fuels, industrial and agricultural wastes, municipal garbage and various low-grade fuels. This combustion is biomass combustion or hybrid combustion of biomass and coal. Generally, coarse particles burn in the lower part of the hearth 8 and fine particles burn in the upper part of the hearth 8. For solid particles blown out from the fume outlet 20 of the hearth, under the effect of the water-cooling wall 17 of the guiding fume directly-raising storage bin, both gas and solid are forced to descend sharply by 180 and flow in the same direction and directly raise to the storage bin 9 through the downward flue 18 and the large capacity-capacity-expanding space 15, so that highly concentrated solid particles are subject to a sharp centrifugal force and drag force first; the failing velocity of solid is made higher than that of airflow particularly due to the blowing of airflow, the weight of solid, the gravity and the vertical falling force from high to low. When the fume turns at a low velocity, fine particles having a specific gravity higher than that of air directly and quickly fall to the bottom of the storage bin; ash continuously burns in the large capacity-capacity-expanding space 15 and burns out and realizes radiative-convective heat exchange, smoke is subject to twice downward and upward turn-over inertia separation by 180° in the separator and a collision-type inertia separation with the over-heater 27 within the upward flue, directly falls to the large capacity-capacity-expanding space then to the storage bin 9 and returns back to the hearth 8 through the dipleg 7 and the back-feeding valve 53 for repeated circulation. The particles complete sufficient combustion and heat exchange during the circulation.
The secondary low-temperature inertia-gravity water-cooling separation process in this embodiment is as follows. The ash in the airflow enters the shaft flue 33 from the upward flue 32; the airflow changes, under the effect of the guiding fume directly-raising storage bin spacer 37 of the separator, its flowing angle within the shaft; the airflow changes, at the lower end of the single-stage or multi-stage coal economizer, to have no local convectional heater face within the shaft; and the guiding fume directly-raising storage bin spacer 37 is arranged in the space so that the airflow highly obliquely runs forward to the outer lower side of the front wall of the shaft. Due to the blowing of the airflow and the weight of the ash, a large amount of ash is gathered onto the wall face of the guiding fume directly-raising storage bin spacer 37 and then slides downward to the large expanding turning passage 45, so that the ash directly falls to the bottom of the storage bin. During the entire process within the secondary low-temperature inertia-gravity water-cooling separator, the fume is subject to one large oblique-degree flowing direction change for inertia separation, one sudden expansion and velocity reduction for gravity separation, and one sudden downward and upward change by 180° for inertia separation, and then enters the storage bin 49. The ash enters the helical back-feeder 52 through the dipleg 50 and returns back to the hearth 8 at regular or irregular interval so as to burn out and to be discharged along with slag. A small amount of ash in the airflow is subject to heat exchange by the coal economizer 110 or air over-heater 51 and then enters the dust removal system to be purified and discharged to the atmosphere.
The hearth of the boiler in this embodiment will be described below. The four walls of the hearth 8 are formed of a membrane wall 5 of the front wall, a membrane wall 4 of the rear wall and the bilaterally symmetric membrane walls 6. The lower end of tube bundle 5 on the membrane wall of the front wall is communicated to the front lower horizontal header 3, while the upper end thereof is bent backward and obliquely extended upward to be radially communicated to the upper horizontal header 24 to naturally form the water-cooling ceiling of the hearth. The lower end of tube bundle 4 on the membrane wall of the rear wall of the hearth is communicated to the rear lower horizontal header 1, while the upper end thereof is communicated to the bilaterally symmetric upper vertical four-in-one header 21. An insulating layer is separately formed on the two sidewalls and the outside of the front wall of the hearth, and an insulating layer is formed on the rear wall of the hearth except for the common wall.
The shaft of the boiler in this embodiment will be described below. For the four walls of the shaft, the membrane wall 31 of the rear wall of the separator forms the common wall of the front wall of the shaft, with its upper end being communicated to the upper horizontal header 29 on the rear wall of the primary high-temperature water-cooling inertia-gravity separator and its lower end being communicated to the lower horizontal header 42 of the tube bundle on the rear wall of the separator. The upper end of the membrane wall 34 of the rear wall of the shaft is bent forward and obliquely extended upward to be radially communicated to the upper horizontal header 26 to naturally form the water-cooling ceilings of both the shaft and the upward flue of the separator. The lower end of the bilaterally symmetric membrane wall 25 of the shaft is communicated to the bilaterally symmetric lower vertical three-in-one header 13, while the upper end thereof is communicated to the bilaterally symmetric upper vertical four-in-one header 21. An insulating layer is separately formed on the two sidewalls and the outside of the rear wall of the shaft, and an insulating layer is formed on the front wall of the shaft except for the common wall.
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In this embodiment, the fume path from the fume outlet 79 of the upward flue 32 of the separator is as follows. The fume enters the fume channel 98 from the fume outlet 79 of the separator; ash having a specific gravity higher than that of air first falls to the ash bucket 108; the hot airflow enters the convention tube flue 93 of the first return stroke through the fume inlet 99 of the convection flue of one return stroke for heat exchange, comes up to the fume channel 95 through the fume outlet 89 of the first convection flue, comes down to the bottom and then turns by 180° to enter the second convection flue 97. The ash collides with the tubes due to sharp large-angle change, and the ash having a specific gravity higher than that of air is inertia-gravity separated from the airflow to fall to the ash bucket 107. The hot airflow comes up to the convention tube flue 97 of the second return stroke for heat exchange and to the fume outlet 90 of the second convection flue, enters the distal end convection flue 92 to be heat exchanged with the convection tube bundle 91, comes down to the bottom, where the ash having a specific gravity higher than that of air falls to the ash bucket 106 first. After many times of upward and downward heat transfer and gas-solid separation, the low-temperature fume and low-concentration smoke enter the dust collector from the smoke outlet 102 to be purified and discharged by the draft fan to the smokestack and finally to the atmosphere.
In this embodiment, the waterway will be described below. The waterway is of a complex circulating type. The convection tube bundle of the header in the distal end. the convection tube bundle of the header of the separator and the tube bundle of the header of the hearth are forced circulating. The convection tube bundles of the upper and lower drums are naturally circulating.
The fed water enters the upper horizontal header 88 from water inlet tube 85 and the communicating tube 86 to be distributed to a plurality of rows of convection tube bundles 91, from which the fed water comes down to the lower horizontal header 103 and then to the front group of lower horizontal headers 105 through the communicating tubes 104 to be distributed to a plurality of rows of convection tube bundles 91 from which the fed water comes up to the upper horizontal header 87 and is then guided to the upper horizontal header 82 and divided into front and rear two horizontal waterways in a staggered manner to flow down; the front waterway 77 enters the lower horizontal header 16 for the guiding fume directly-raising storage bin and then enters the bilaterally symmetric lower vertical two-in-one header 13 through the communicating tubes 143, while the rear waterway 81 enters the lower horizontal header 42 on the rear wall of the separator and then enters the bilaterally symmetric lower vertical two-in-one header 13; both waterways are distributed to the tube bundle 25 on the bilaterally symmetric water-cooling wall through the bilaterally symmetric lower vertical two-in-one header 13, come up to the bilaterally symmetric upper vertical header 76, run to the front end to be distributed to the tube bundle 6 on the bilaterally symmetric water-cooling wall of the hearth, enter the bilaterally symmetric lower vertical header 3 of the hearth and enter the front and rear horizontal headers 3, 1 of the hearth through the communicating tubes 144 to be distributed to the tube bundles 5, 4 on the front and rear water-cooling walls, come up to the upper horizontal header 24 of the hearth, and enter the upper drum 84 through water guide tubes 78 and enter the lower drum 101 through the convection tube bundle 94 and, due to the difference of proportion of the fed water and the drained water, hot water circulates naturally in the upper and lower drums 84, 101 through the convection tube bundle 94, and hot water is carried to the heat supply system through the water outlet 74.
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the upper ends of the horizontal tube bundles 156, 157, 17, 31, 128, 139 of different length from front to back in four or six rows in the upper part are communicated to the upper horizontal headers 60, 24, 26, 124, 125, 163 of same length from front to back, respectively, and the lower ends thereof are communicated to the lower horizontal headers 153, 155, 16, 31, 39, 165 of the same length in the upper part, respectively; and, the upper ends of four short communicating tubes 69 of the same length and of three long communicating tubes 121 of the same length in the upper part are communicated to the drum 63 or upper central header 161, respectively, and the lower ends thereof are communicated to the upper horizontal header 69, 121 in the upper part, respectively; and a gap between the long communicating tubes 121 is a fume outlet, and the short communicating tubes 69 are sealed wall tubes.
For the lower part, the upper end of the bilaterally symmetric membrane wall 6 in the lower part is communicated to the bilaterally symmetric upper vertical header 149 in the lower part while the lower end thereof is communicated to the bilaterally symmetric lower vertical header 2, the upper end of the front membrane water-cooling wall 5 in the lower part is communicated to the front upper horizontal header 146 in the lower part while the lower end thereof is communicated to the lower horizontal header 1 in the lower part, and the upper end of the front membrane water-cooling wall 5 in the lower part is communicated to the front upper horizontal header 150 in the lower part while the lower end thereof is communicated to the lower horizontal header 3 in the lower part; the upper ends of the communicating tubes 148 of the vertical headers are communicated to the bilaterally symmetric vertical headers 152 in the upper part while the lower ends thereof are communicated to the bilaterally symmetric upper vertical header 149 in the lower part, the upper ends of the communicating tubes 151, 154 of the horizontal headers are communicated to the lower horizontal header 153, 155 in the upper part while the lower ends thereof are communicated to the upper horizontal header 150, 146 in the lower part
The equalizing, separating and heat storing device 147, referring to
Measures and methods for reducing the height of the boiler body for a split boiler of ton vapor ≤35 T
(1) Strengthened gas-solid in-separation: for the dense-phase zone of the boiler, a high-rate circulating air distributor is employed, while for the dilute-phase zone, an ultra-low-rate circulating volume of a cross-sectional velocity ≤5 M is employed. The water-cooling degree of both the transition segment and the dilute-phase zone is increased, the boiling height of fuel is increased to highly strengthen the heat exchange with the space with a high water-cooling degree and the transition segment and to balance the temperature of the dense-phase zone, and the difference in velocity between the dense-phase zone and the sparse-phase zone is enlarged so that large and middle particles circulate and exchange heat upward and downward within the hearth in a high rate. An equalizing, separating and heat storing device made of refractory material is provided in the middle upper part of the dilute-phase zone so that a large amount of fine particles collide with the device and then fall into the sparse-phase zone (suspending combustion chamber) for continuous combustion,
(2) Strengthened gas-solid out-separation: the secondary air is strengthened at the upper end of the transition segment of the dense-phase zone, and the concentration of gas and solid of the dilute-phase zone and the concentration of gas and solid passing through the equalizing, separating and heat storing device are increased. Under the effect of the water-cooling wall of the guiding fume directly-raising storage bin, a property of directly conveying solid to the storage bin by the airflow is formed. The gas and solid are forced to descend sharply by 180° from the outlet of the hearth so that gas and solid flow in the same direction and directly raise to the large capacity-capacity-expanding space to the storage bin, and due to the sharp centrifugal force and drag force, the blowing of airflow, the weight of solid and the gravity, the falling velocity of solid from high to low is made higher than that of airflow. The fume suddenly expands and slows down at the outlet of the downward flue and further flows at a low velocity in the upward flue, so that fine particles having a specific gravity higher than that of air may be separated and the ash may be gathered.
(3) Measures for strengthening complete combustion: from the air distributor to the outlet of the hearth, there are three sections, i.e., a boiling combustion section, a suspending combustion section and a high-temperature combustion section. Those sections are differently designed in volume and water-cooling degree. Specifically, the water-cooling degree of the suspending combustion section is increased, and the water-cooling degree of the low-temperature and high-temperature sections is decreased (the heating face is reduced or the surrounding zone is increased), The equalizing, separating and heat storing device is disposed at the upper end of the suspending combustion section, thereby increasing the cross-sectional resistance, thus gathering heat in the suspending combustion chamber to stabilize the combustion temperature of the hearth having a large volume and a large water-cooling degree. In this way, fine particles are made to collide with the device and then fall due to inertia separation into the suspending combustion chamber for continuous combustion: furthermore, this device forces the airflows to interact with each other from the gaps and the solid particles to interact and collide with each other to break the crust so that the carbon particles may contact and react with oxygen wall, which facilitates continuous combustion. Consequently, ash clinging to the high-temperature wall of the heat storing device burns out. The temperature of the upper part of the boiler and the temperature of the separator are both increased, the up-down return stroke of the fume is increased, and temperature and time duration for sufficient combustion of combustibles are guaranteed, and the content of carbon in the ash is reduced.
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A phase-transformation heat-exchange hot-water boiler is a heat-exchange apparatus which exchanges heat by the boiling evaporation and condensation of a heating medium so as to transfer heat and to heat water. It consists of two parts, i.e., an evaporative heat exchanger and a condensing heat exchanger. A boiler combustion chamber and a radiative convection heating face are provided in the evaporative heat exchanger. Heat generated by the combustion of fuel facilitates the heating medium water within the heating face to generate saturated steam under a corresponding pressure. The steam comes up to the condensing segment to be condensed within the condensing heat exchanger to produce latent heat of vaporization, and the heat is transferred to the hot water within the heat exchanger. Finally, the water is heated to a certain temperature to be delivered to hot-water users. The condensed water returns back to the evaporative heat exchanger for evaporation and vaporization so that it supplies heat to the outside continuously. In this way, without the need of supplementing raw water or just by supplementing a very limited amount of water into the evaporative heat exchanger, the possibility of generation of scales is fundamentally solved. Therefore, the boiler may be avoided from scaling, oxygen corrosion, need of sewage drainage, and use of any water softening device and deoxygenization device. Both the operating efficiency and the service life of the boiler are increased and the loss of heat is reduced; furthermore, the investment on assistant apparatuses may be reduced and the operating expense may be thus significantly reduced. The various defects of the present hot-water boils are substantially solved. Such a boiler is an irreplaceable energy-saving, water-saving, consumption-reducing and emission-reducing heat supply boiler in the field of centralized heating.
The phase-transformation heat-exchange hot-water boiler main body having two drums in this embodiment includes a heat exchanger 183, two drums 184, bilaterally symmetric upper, middle and lower vertical headers 180, 170, 2, upper, middle and lower horizontal headers 179, 178, 176, 185, 186, 169, 168, 16, 190, 1, 3, bilaterally symmetric convection tube bundle 191, communicating tubes 182, 194, 196 and the like. It is characterized in that there is a plurality of communicating tubes 182 disposed vertically, with their upper ends being communicated to the center of the lower part of the heat exchanger 183 and their lower ends being communicated to the center of the upper part of the drums 184; the lower end of the inner side of the communicating tube 197 is radially communicated to the slightly outer side of the upper part of the two drums 184, while upper end of the outer side thereof is communicated to the center of the inner side of the heat exchanger 183; there are five communicating tubes 194 separately vertically disposed on the two drums, with their upper ends being radially communicated to the inner side of the drums and their lower ends being respectively communicated to the upper horizontal headers 179, 178, 176, 185, 186; there is a plurality of communicating tubes 196 vertically disposed, with their two ends being respectively communicated to the center of the inner side of the drums 184; there is a plurality of communicating tubes 207 vertically disposed, with their upper ends being communicated to the center of the lower part of the heat exchanger 183 and their lower ends being communicated to the center of the upper part of the upper vertical header 180; the two ends of the upper horizontal headers 179, 178, 176, 185, 186 are respectively communicated to the center of the inner side of the bilaterally symmetric upper vertical header; the two ends of the middle horizontal headers 169, 168, 16, 190 are respectively communicated to the center of the inner side of the bilaterally symmetric middle vertical header; the upper end of the membrane wall 173 of the front wall of the boiler is communicated to the lower part of the upper horizontal header 179, while the lower end thereof is radially communicated to the middle horizontal header 169; the upper end of the membrane wall 172 of the front wall of the hearth is communicated to upper horizontal header 178, while the lower end thereof is radially communicated to the middle horizontal header 169; a space from the membrane wall 173 of the front wall of the boiler to the membrane wall 172 of the front wall of the hearth forms a fume channel 174; the upper end of the membrane wall 168 of the rear wall of the hearth is communicated to the upper horizontal header, while the lower end thereof is communicated to the middle horizontal header 167; the upper end of the membrane wall 17 upper end of the guiding fume directly-raising storage bin is communicated to the upper horizontal header 185, while the lower end thereof is communicated to the middle horizontal header 16; the upper end of the membrane wall 188 of the rear wall of the boiler is communicated to the upper horizontal header 186, while the lower end thereof is communicated to the middle horizontal header 190; the upper end of the ceiling tube 202 of the hearth is communicated to the center of the lower part of the drum 184, while the lower end thereof is radially communicated to the inner upper side of the bilaterally symmetric upper vertical header; the upper end of the membrane ceiling 200 of the boiler is radially communicated to a part slightly below the center of the side part of the drum 184, while the lower end thereof is communicated to the center of the upper part of the bilaterally symmetric upper vertical header; the upper end of the convection tube bundle 210 is radially communicated to the lower part of the bilaterally symmetric upper vertical header 180, while the lower end thereof is radially communicated to the upper part of the bilaterally symmetric middle vertical header 170; the upper end of the membrane wall 3 of the front wall of the hearth is radially communicated to the lower part of the middle horizontal header 169, while the lower end thereof is communicated to the lower horizontal header 3; the upper end of the membrane wall 4 of the rear wall of the hearth is communicated to the lower part of the middle horizontal header 167 while the lower end thereof is communicated to the upper part of the lower horizontal header 1; the upper end of the bilaterally symmetric membrane wall 6 is radially communicated to the lower inner side of the bilaterally symmetric middle vertical header, while the lower end thereof is communicated to the upper part of the bilaterally symmetric lower vertical header 2; the upper ends of the descending tubes 181, 189 are respectively radially communicated to the lower parts of the two ends of the drum, while the lower ends thereof are communicated to the upper parts of the two ends of the bilaterally symmetric middle vertical header 170; the lower end of the descending tube 166 is communicated to the centers of outer sides of the two ends of the lower vertical header 2, while the upper end thereof is communicated to the middle vertical header 170; the lower end of the descending tube 166 is communicated to the upper parts of the two ends of the lower horizontal header 1, while the upper end thereof is communicated to the middle horizontal headers 169, 168; and there is a plurality of ash buckets 204 mounted at the lower end of the outside of the bilaterally symmetric middle vertical header 170, and the lower ends of the ash buckets 204 are communicated to the ash discharge tube 205.
The space from the ceiling 202 of the hearth to the ceiling 200 of the boiler forms the upper vertical flue 201, the space from the membrane wall 173 of the front wall of the boiler to the membrane wall 172 of the front wall of the hearth to the bilaterally symmetric membrane wall 177 forms the fume channel 174, the space from the membrane wall 172 of the front wall of the hearth to the membrane wall 168 of the rear wall of the hearth to the bilaterally symmetric membrane water-cooling wall 177 forms the hearth 8, the space from the membrane wall 168 of the rear wall of the hearth to the membrane wall 17 of the guiding fume directly-raising storage bin to the bilaterally symmetric membrane wall 177 forms the downward flue 18, and the space from the membrane wall 17 of the guiding fume directly-raising storage bin to the membrane wall 188 of the rear wall of the boiler to the bilaterally symmetric membrane wall 177 forms the upward flue 32; and the gaps in a plurality of rows between the convection tube bundles 191 form the convection flue 203.
The part from the upper end of the upper horizontal header 177 on the membrane wall 168 of the rear wall of the hearth to the ceiling 202 of the hearth, to the communicating tubes 196 and to the inner lower end of the drum 184 is completely unblocked as an outlet for fume from the hearth; the part from the membrane wall 17 of the guiding fume directly-raising storage bin, the membrane walls 173, 188 of both the front wall and the rear wall of the boiler, and the upper ends of the upper horizontal headers 185, 179, 186, 178 communicated to the four membrane walls to the ceiling 202 of the hearth, to the communicating tubes 196 and to the inner lower end of the drum 184 is made of refractory material structure or heat-resisting steel plate structure to form a sealed isolating wall; and the lower ends of the wall tubes 193 are respectively communicated to the upper horizontal headers 179, 186 while the upper ends thereof are radially communicated to the drum 184 to form a front and a rear external water-cooling wall for the boiler,
There are total four heat exchangers 183 respectively communicated to the top of both the drum 184 and the bilaterally symmetric upper vertical header 180, and two drums.
For the inner circular diameter of the bilaterally symmetric upper and middle vertical headers: the inner circular diameter of the upper and middle vertical headers of a boiler of ton vapor ≤40 is less than or equal to 450 mm, the inner circular diameter of the upper and middle vertical headers of a boiler of ton vapor ≥100 is larger than or equal to 900 mm; and there is a plurality of ash buckets mounted vertically at the lower end of the outer side of the bilaterally symmetric middle vertical header, with the lower ends of the ash buckets being connected to the ash discharge tube.
With regard to the waterway of the evaporative heat exchanger, the hearth 8 and the radiative convection heating faces 4, 5, 6, 17, 168, 172, 173, 177, 188, 191, 200, 202 are provided in the evaporative heat exchanger; heat generated by the combustion of fuel facilitates the heating medium water within the heating faces to generate saturated steam under a corresponding pressure and enables the saturated steam to rise and gather in a steam space of the drum 184, the steam enters the heat exchanger through the communicating tubes 182, 197 to be condensed to produce latent heat of vaporization, the heat is transferred to the hot water within the tubes of the heat exchanger, the condensed water enters the middle horizontal header 190 and the lower vertical and horizontal headers 2, 1 through descending tubes 181, 189, 166, 206 and then respectively enters the radiative-convective tube bundles 4, 5, 6, 17, 168, 172, 173, 177. 188, 191, 200, 202 and comes up to the heat exchanger 183 to be condensed to produce latent heat of vaporization, the condensed water returns to the evaporative heat exchanger for evaporation and vaporization, so as to achieve the never-ending cycle of ascending and descending circulation and thus supply heat to the outside continuously.
With regard to the waterway of the condensing heat exchanger, the fed water enters the tube bundle of the heat exchanger 183 through the water inlet tube 192 in the distal part, runs forward to the front end and enters the second heat exchanger 183 through the communicating tube 198, runs backward to the distal end and enters the third heat exchanger 183 through the communicating tube 195, runs forward to the front end and enters the fourth heat exchanger 183 through the communicating tube 198, and finally runs backward to the distal end to be carried to the heat supply system through the water outlet 199.
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The wear-resistant treatment to the separator of Embodiments 1-27 is carried out on the wall face of the downward flue 18. For low fume velocity, it is just to be carried out on local wall face of the downward flue. And, the entire of the upward flue 32 is an unexposed heating face.
The water-cooling wall 17 of the guiding fume directly-raising storage bin of Embodiments 1-27 is any one of a full-membrane-wall structure, a semi-membrane wall structure, a full-light pipe poured refractory material structure and a dry refractory wall structure. and the internal and external appearance structures of the separator are rectangular, square and circular; the four walls of the hearth 8 are any one of a full-membrane-wall structure, a semi-membrane wall structure and a full-light pipe poured refractory material structure, and the internal and external appearance structures are rectangular, square and circular; and the four walls of the shaft 32 may be any one of a full-membrane-wall structure, a semi-membrane wall structure, a full-light pipe poured refractory material structure and a dry refractory wall structure, and the internal and external appearance structures are rectangular and square.
The fuel inlet, the desulfurizer inlet, the slag outlet, the circulating material inlet, the air distributor, the primary and secondary air inlets, the outlet of the hearth, the boiler door, the blast door, the observation hole, the measurement hole, the manhole and the like of Embodiments 1-27 are all designed in accordance with the existing technical standards.
The water circulation for the water-cooling wall tube of the hearth, the water circulation for the water-cooling wall tube of the separator, the water circulation for the water-cooling wall tube of the shaft, the water circulation for the phase-transformation heat-exchange, the steel racks and insulating functions, the over-heater, the re-heater, the coal economizer, the air pre-heater and the like of Embodiments 1-27 are all designed in accordance with the universal technical standards.
The upper part of the drum 22 of a steam boiler or a power plant boiler is communicated to the gas guide tube, while the lower part thereof is communicated to the descending tube. All lower horizontal and vertical headers are communicated to the descending tubes fitted thereto, and all upper horizontal and vertical headers are communicated to the gas guide tubes fitted thereto. The hot-water boiler is designed in accordance with the existing universal technical standards.
All different structures, different components and different points in Embodiments 1-27 may be optimized and combined to new models of boilers.
The fundamental principle and preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to those specific implementations, and those implementations are solely illustrative without any sense of limitation. With the teaching of the present invention, various forms may be made by one of ordinary skill in the art without departing from the gist and scope of the present invention to be protected by the claims, and those forms are included within the protection scope of the present invention.
This application is a continuation-in-part of International Patent Application No. PCT/CN2014/092168 with an international filing date of Nov. 25, 2014, designating the United States, now pending. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4462341 | Strohmeyer, Jr. | Jul 1984 | A |
| 4745884 | Coulthard | May 1988 | A |
| 5133943 | Abdulally | Jul 1992 | A |
| 5138958 | Sinquin | Aug 1992 | A |
| 5269263 | Garcia-Mallol | Dec 1993 | A |
| 5463968 | Abdulally | Nov 1995 | A |
| Number | Date | Country |
|---|---|---|
| WO 2012075727 | Jun 2012 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20160146452 A1 | May 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2014/092168 | Nov 2014 | US |
| Child | 14737492 | US |
