Patent Application
20150136370
The present invention relates to a heat exchanging apparatus for heating or cooling fluid instantaneously.
Heat exchanging apparatuses include an apparatus that heats gas, for example. A commonly-used structure thereof is such a structure that gas is heated by making the gas flow through a heated pipe. An alternative structure is such a structure that heated fluid is caused to flow in a pipe having fins, and gas is heated by making the gas flow between the fins.
These structures are used to heat not only gas but also liquid or to generate water vapor. An apparatus for not heating gas but cooling gas generally has a similar structure.
This structure is common and conventional, but the apparatus needs to be large in volume. The reason is that the efficiency of heat exchange between the pipe and the fluid flowing through the pipe is low.
A structure to improve the efficiency of heat exchange in this common structure has been suggested. Examples of the inventions are illustrated in
The reference numeral 38 in
At this time, nitrogen gas is introduced into the pair of left and right first and second upper gas introducing longitudinal holes 29, 30 of the heating apparatus from the first and second gas introducing pipes 18a, 18b. The nitrogen gas is heated to a required high temperature (for example, 650° C.) until the nitrogen gas reaches first and second jetting holes 35, 36 via the pair of left and right grooves 27, 27 . . . , 28, 28, . . . , and the first and second lower gas jetting longitudinal holes in this order. Production of high-temperature gas was succeeded by the small-sized heating apparatus.”
For example, according to calculation, the speed of gas passing through a pipe having a 1-cm2 cross-section at a flow rate of 100 SLM (standard liter per minute) is 16 m/second. Assuming that the gas smoothly flows through the pipe, the time required for the gas to pass through an apparatus having such a flow passage cross-section is 0.01 seconds or less. That is, the gas is heated instantaneously up to the temperature of heated carbon. The structure shown in
An apparatus that heats gas instantaneously and jet out the high temperature gas is applied not only to heating or drying but also to a process for heating and baking various materials (metal, a dielectric material, or the like) applied over a substrate. These apparatuses are also useful for heating liquid, such as water.
An apparatus that cools gas instantaneously is applied to cooling of water vapor from a turbine, cooling of a coolant of a cooling and heating machine, cooling of exhaust heat of a boiler, or the like. The application to cooling of a coolant is promising in geothermal generation that has recently attracted attention.
The present invention relates to an apparatus that performs efficient instantaneous heating or instantaneous cooling of fluid, such as liquid or gas.
The physics of a heat exchanger structure of the present invention lies in increasing the flow speed of gas in a flow passage of narrow longitudinal grooves, thereby making the fluid impinge against walls of flow passages of horizontal grooves perpendicularly at high speed to perform heat exchange between the walls of the flow passages of the horizontal grooves and the gas efficiently. This physics holds not only for gas but also for fluid, including liquid.
The structure shown in
In order to increase the flow speed of the fluid in the flow passage of the longitudinal groove to make the fluid impinge powerfully against the wall of the flow passage of the horizontal groove thereby improving the efficiency of heat exchange, it is necessary to design the flow passage of the longitudinal groove according to the horizontal groove.
In this regard, if it is easy to perform cutting to form a flow passage composed of a groove having a small cross-section, the cutting cost is not high. In the patent literature 2, an example is shown in which the width of the flow passage of the longitudinal groove is 1 mm and the width of the flow passage of the horizontal groove is 7 mm. These dimensions are clearly effective to achieve the object of high-speed impingement, but this is merely one example.
There are many combinations of effective widths of the flow passage of the longitudinal groove and the flow passage of the horizontal groove. If the depth of the flow passage of the groove is 1 mm to 3 mm, the flow passage of the longitudinal groove can be easily machined by an end mill. If a material that cannot be easily cut is used, the flow passage of the longitudinal groove cannot be easily machined, the cutting work adversely affects the manufacturing cost.
Therefore, the design of the prior art structure satisfying easy machining is required. Then, the design guidelines for the dimensions of the horizontal flow passage need to be established.
One or more embodiments of the present invention are heat exchanging apparatuses in which a base in which a flow passage for fluid is formed is jointed to a sealing plate sealing the flow passage to form an airtight flow passage, the flow passage including first flow passages opened outside in a surface of the base, elongated in one direction, and formed in a plurality of stages in one direction of the base at required intervals, and a plurality of second flow passages perpendicular to the first flow passages and connecting adjacent first flow passages of the first flow passages in a communicating manner, in a structure of the heat exchanging apparatus where a flow passage is formed such that fluid introduced into a first flow passage of the first flow passages located at one end passes through the first flow passage located at one end and the second flow passages and reach a first flow passage of the first flow passages located at the other end, and fluid introduced into the flow passage impinges perpendicularly against walls of the first flow passages to perform heat exchange, and the fluid is discharged from a fluid outlet hole located at the other end of the flow passage, wherein a flow speed in the second flow passages is higher than a flow speed in the first flow passages.
One or more embodiments of the present invention are the heat exchanging apparatuses according to the first embodiment, wherein two or more of the following conditions are satisfied: a cross-sectional area St of the first flow passages is twice as large as a cross-sectional area Sc of the second flow passages; a length L of the second flow passages is longer than a width WW of the first flow passages; and an arrangement pitch of the second flow passages is twice as large as a width of the second flow passages.
One or more embodiments of the present invention are the heat exchanging apparatuses according to the first or second embodiment, wherein the base in which the flow passage is formed is either one of a plate and a tube having a cylindrical, columnar, or prismatic shape.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to third embodiments, wherein the base and the sealing plate are composed of at least one of metal, graphite, ceramic, plastic, and a composite material.
One or more embodiments of the present invention are the heat exchanging apparatuses according to the fourth embodiment, wherein the composite material is a composite material of two or more of metal, metal fiber, carbon nanotube, graphene, carbon fiber, and plastic.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to fifth embodiments, wherein the structure is manufactured by machining the base by means of a die to shape the first and second flow passages, and joining the sealing plate to the base.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to sixth embodiments, wherein a material surface of the heat exchanging apparatus is lined with resin, coated, plated, or protected with an oxide film.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to seventh embodiments, wherein the fluid is gas or liquid.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to eighth embodiments, wherein the fluid is steam having a temperature exceeding 100° C.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to ninth embodiments, wherein the heat exchanging apparatus heats the fluid by being mounted with a heater or being placed in a heated high-temperature medium.
One or more embodiments of the present invention are the heat exchanging apparatuses according to any one of the first to ninth embodiments, wherein the heat exchanging apparatus cools the fluid by being brought into contact with a low-temperature medium or being placed in a low-temperature medium.
One or more embodiments of the present invention are heat exchanging apparatuses, wherein two heat exchanging apparatuses according to any one of the first to eleventh embodiments are joined together, and first fluid and second fluid are caused to flow through the two heat exchanging apparatuses, respectively.
One or more embodiments of the present invention are apparatuses which bring high-temperature steam generated by the heat exchanging apparatus according to any one of the first to twelfth embodiments into contact with organic matter or gas containing organic matter.
According to one or more embodiments of the present invention, the design guidelines for the structure to make the fluid impinge perpendicularly against the wall of the flow passage are applicable regardless of the size or shape of the heat exchanging apparatus.
Since the design guidelines are merely guidelines, Sc, St, L, WW, P and W can be arbitrarily set within an acceptable machining cost range as long as high-flow-speed impingement occurs. When the flow rate is desired to be set large, it is preferred that the cross-section of the flow passage be enlarged within a reasonable machining cost range according to the design guidelines.
According to one or more embodiments of the present invention, the material can be selected according to a use temperature, a heat medium environment, or the cutting work cost of the base.
As the material, a surface-treated metal, a resin-lined metal, a metal with a surface oxide film, or a plastic composite material having an increased thermal conductivity can be used. From these materials, a material preventing corrosion or wear due to contact with the fluid or the heat medium can be selected.
Therefore, it is possible to heat or cool such fluid as corrosive chemicals or penetrative toxic gas.
When an easily-deformable material is selected as the material, the flow passage can be formed by die pressing. When a metal plate is selected, the metal plate can be joined by welding or an electric welder. A plastic material can be joined with an adhesive. Swaging is an easy method for canning. Since existing processing facilities can be used according to selection of the material, the manufacturing cost for producing the heat exchanging apparatus can be reduced.
According to one or more embodiments of the present invention, gas and liquid can be handled as fluid.
When oxygen is selected as the fluid, heated oxygen can be produced instantaneously. When hydrogen or formic acid is selected as the fluid, high-temperature reducing gas can be produced instantaneously. When an oxide film on a bump surface is reduced, melting of the bump occurs at low temperature in a well-reproducible manner, so that the bump joining process becomes stable.
When air and town gas are selected as the fluid, high-temperature air and fuel can be introduced into a boiler in a mixed manner, so the combustion temperature rises and the combustion efficiency improves, which results in saving the town gas. The heated air improves the combustion efficiency of an internal combustion engine so that such fuel as fuel oil can be saved.
When water is heated into superheated steam of 100° C. or higher, heating or drying can be performed in the absence of oxygen. When ribbed mutton was roasted with superheated steam of 300° C., the strings of the meat became tender.
High-temperature steam can be produced at hand and utilized for drying of dry-cleaning that should avoid oxidation or for instantaneous drying of printing ink.
When material chips having high thermally-insulating properties stored in a container are desired to be heated, it is time-consuming to heat the container because of the high thermally-insulating properties.
In such a case, by introducing heated steam, air, or nitrogen, the thermally-insulating material can be heated or melted in a short time. When thermally-insulating materials having different melting temperatures are desired to be mixed, it is preferred that these materials be individually heated by gas in advance. In such a case, gas heated to a desired temperature by the heat exchanging apparatus of the present invention can be used.
When radioactive contaminants are cooled with water in nuclear power plants, radiation-contaminated water is generated and the contaminated water causes a disposal problem. There is the idea of cooling the radioactive contaminants by air in order not to generate contaminated water. In that case, an apparatus for cooling a huge amount of air instantaneously at site is required. The heat exchanging apparatus of the present invention is advantageously applied for that purpose.
According to one or more embodiments of the present invention, in order to heat the heat exchanging apparatus, an electric heater or a high-temperature exhaust gas can be used as a high-temperature heat medium. In order to prevent burn injury when the heat exchanging apparatus has a high temperature, the heat exchanging apparatus is enclosed by a thermally-insulating member and housed in a case.
When the heat exchanging apparatus is desired to be cooled to a low temperature, the heat exchanging apparatus may be brought into contact with water serving as a low-temperature medium, or immersed in water.
According to one or more embodiments of the present invention, only heat can be exchanged with no contact between gas and gas, liquid and gas, or liquid and liquid.
Since the heat exchanging apparatuses are in back-to-back contact with each other, the volume of the heat exchanger is small and the heat-exchange efficiency is high. By selecting a material for the heat exchanging apparatus, a heat-exchanging method that can avoid such a problem as corrosion, wear, or toxicity, can be realized.
When this structure is adopted to indoor equipment and outdoor equipment of a cooling machine, the advantageous effect of reducing the respective sizes of the indoor equipment and the outdoor equipment can be achieved since this structure has a small volume unlike a large-volume pipe having fins.
According to one or more embodiments of the present invention, reusable gas having a high chemical potential can be extracted from meat, vegetables, or wood chips so that the gas can be reused as a fuel resource.
In order to describe the above design guidelines, a basic part of a heat exchanger is illustrated in
Flow passages of grooves that are structures similar to those of Patent Literature 2 are formed in a base 301 on which the heat exchanging apparatus 300 is constructed. A sealing plate 302 seals the groove flow passages to form flow passages. The base 301 is heated or cooled, and fluid flows through the flow passages to exchange heat with the base 301.
Buffer tubs 305, 306 are provided at both ends of the flow passages in
Tubs T1, T2, T3, T4, T5 correspond to the flow passages of the horizontal grooves 27 or 28 in the patent literature 2.
The tubs T1 to T5 form flow passages and the tubs T1 to T5 are sometimes referred to as first flow passages in the following structural description. The width of each of the tubs T1 to T5 is denoted by WW, and the depth of each of the tubs T1 to T5 is denoted by DD.
Channels CH correspond to the flow passages of the longitudinal grooves 38 in the patent literature 2. Channel flow passages connected to the same tub flow passage are collectively referred to as channel row, and the channel rows are assigned with numbers in the order, like CH1, CH2, CH3, CH4, and CH5. The channels in the same channel row are also assigned with numbers, for example, the channels in the channel row CH2 are assigned with CH21, CH22, CH23, CH24, CH25, and CH26 (see
In the following structural description, the channels forming the flow passages are sometimes referred to as second flow passages.
The pitch of channel arrangement in the same channel row is denoted by P. Channel central axes P1 and P2 of adjacent channel rows are arranged so as to be out of alignment by one half of the pitch. The width of the channel CH is denoted by W. The depth of the channel CH is denoted by D. The length of the channel is denoted by L.
As described above, fluid passes through the tubs that are first flow passages and the channels that are second flow passages.
The guidelines for dimensional design that causes efficient heat exchange in the prior art structure are explained below.
A first guideline is a relationship between the cross-sectional area of the tub T (denoted below by St) and the cross-sectional area of the channel CH (denoted below by Sc). Since the structure is such that the fluid leaving the channel CH flows in a diverging fashion in two directions, if simply 2Sc=St, no change in the speed of the flow occurs and no pool is formed. That is, 2Sc=St is considered to be a dimensional relationship in which flows of the same speed without turbulence are formed.
If St≦2Sc, that is, if the flow speed in the channel is slower than the flow speed in the tub, St≦2Sc is defined as a relationship in which either (i) the fluid does not impinge against the wall of the tub, or (ii) a relationship in which a laminar flow is generated.
When a laminar flow flowing along the tub wall without being disturbed is formed, the efficiency of heat exchange with the wall significantly lowers.
A relationship in which the fluid impinges against the wall is defined as 2Sc<St in the opposite meaning of the condition under which a laminar flow is formed.
A second guideline is a relationship between the length L of the channel CH and the width WW of the tub T.
In order for a flow that has gained a high flow speed in the channel CH to reach the wall of the tub T and impinge against the wall, the width WW of the tub T is desired to be at least shorter than the length L of the channel CH. When it is defined that a distance of transmission of the high flow speed of the flow that has left the channel CH to the wall corresponds to the length L of the channel CH, a design guideline that causes impingement is L>WW.
A third guideline is a positional relationship between the channels in the channel rows adjoining via the tub.
When the central axes P1 and P2 of the channels in the adjacent channel rows are coincident with each other, the fluid passing through the channel passes transversely through the in-between tub as a uniaxial laminar flow. That is, the fluid never impinges against the wall of the tub.
Even when the central axes P1 and P2 are not completely coincident with each other, as long as the channels in the adjacent channel rows partially overlap with each other, a flow that does not impinge against the tub wall is formed since the fluid flows preferentially into an easy-to-flow flow passage. Therefore, the channels in the adjacent channel rows must be arranged so as not to overlap with each other.
The overlapping portion is created when P≦2W is satisfied if the channel pitch P is used for representation.
Therefore, in order to avoid causing the channels in the adjacent channel rows to overlap with each other, P>2W needs to be satisfied.
The design guidelines to cause the fluid to impinge against the wall of the tub without forming a laminar flow have been described above. These guidelines are the present guidelines.
The present guidelines are summarized as follows:
2Sc<St (Sc, St are the cross-sectional areas of the channel CH and the tub T, respectively);
L>WW (L is the length of the channel CH, WW is the width of the tub T); and
P>2W (P, W are the arrangement pitch and the width of the channel CH, respectively).
Though
The channel may be not a groove but a hole. The shape of a cross-section of the tub may be rectangular, triangular, or elliptical.
The materials of the base 301 and the sealing plate 302 forming the prior art structure may be metal, graphite, ceramic, plastic, a composite material, or a combination of these.
The composite material may be a composite material of at least two or more of metal, carbon nanotube, graphene, carbon fiber, and plastic.
The material may be a plate, and the prior art structure may be manufactured by machining the plate as the base 301 by means of a die to shape the channels and the tubs in the base 301, and joining the sealing plate 302 to the base 301 by bonding.
When a peripheral material coming into contact with the heat exchanging apparatus 300 or the fluid has corrosive properties, the material surface of the heat exchanging apparatus 300 may be lined with resin, coated, or plated. The material surface may also be oxidized and protected with an oxide film.
Joining the base 301 and the sealing plate 302 to each other may be made by screwing. A rubber packing, a carbon packing, or another seal packing can also be used to join the base 301 and the sealing plate 302.
The above joining may also be joining performed by an adhesive.
The above fluid may be gas (air, for example) or liquid (water, for example).
Water is a special source material. Since water can be used as a source material of steam gas without specially preparing gas, water can be utilized as gas containing no oxygen gas.
High-temperature steam having a temperature of higher than 100° C. has a high ability of decomposing organic matter. If organic waste, such as meat, vegetables, wood chips, or plastics, is brought into contact with steam of approximately 1000° C., molecules thereof are cleaved or decomposed, and gas containing hydrogen, carbon, or oxygen is generated.
Even when meat is brought into contact with steam with a temperature lower than this temperature, for example, high-temperature steam of approximately 300° C., the strings of the meat can be changed so that the meat becomes tender and easy to chew. This is applicable to a safe barbecue using no fire.
The above gas having a high chemical potential that is extracted by bringing the above high-temperature steam and the gas containing waste or organic matter is reusable as an energy resource. Therefore, the heat exchanging apparatus performing this is an organic matter treatment apparatus.
The heat exchanging apparatus 300 is a single unit illustrated in a planar shape, but can be bent into a tube having a triangular or rectangular shape or other polygonal shapes. The heat exchanging apparatus 300 can take a cylindrical shape when being made from a plate having a circular tubular shape, not a planar shape.
The number, shapes, or arrangement positions of the fluid outlets 304 or the fluid inlets 303 can be freely designed. When a plurality of heat exchanging apparatuses 300 are connected, the plurality of heat exchanging apparatuses 300 can be connected in series by connecting the fluid inlet of an heat exchanging apparatus to the fluid outlet of another heat exchanging apparatus, or connected in parallel by connecting the fluid inlets of these heat exchanging apparatuses and connecting the fluid outlets of them.
Instead of changing the shape of the heat exchanging apparatus 300, a plurality of heat exchanging apparatuses 300 may be bonded to a surface of another tube or plate.
In order to heat fluid, a heater may be attached to the heat exchanging apparatus 300, or the heat exchanging apparatus 300 may be placed in a heated medium.
For example, it is known that it is effective to introduce air heated to high temperature in order to improve the combustion efficiency of a boiler. In order to achieve this object, it is preferred that the heat exchanging apparatus 300 be brought in contact with a combustion chamber or an exhaust piping of the boiler or be placed in the combustion chamber or the exhaust piping of the boiler to heat air so that the heated air can be introduced as heating air.
In order to cool the fluid, a coolant may be brought into contact with the heat exchanging apparatus 300, or the heat exchanging apparatus 300 may be placed in a low-temperature medium.
For example, high-temperature gas from a turbine or a combustion chamber can be efficiently cooled by causing the high-temperature gas to flow through the heat exchanging apparatus 300 as fluid and cooling this heat exchanging apparatus 300 in seawater.
In some cases, heat exchange between first gas and second gas is desired to be performed instantaneously. In order to achieve this object, it is preferred that a first heat exchanging apparatus 300 and a second heat exchanging apparatus 300 be jointed back to back via the sealing plate 302, and first gas be caused to flow through the first heat exchanging apparatus 300 and second gas be caused to flow through the second heat exchanging apparatus 300.
For example, when ammonia used in geothermal generation is desired to be cooled by air, high-temperature ammonia gas can be used as first gas, and air as second gas.
Design parameters of example 1 and example 2 are shown in
2Sc<St;
L>WW; and
P>2W.
In the example 1, a heat exchanging apparatus was manufactured by machining a stainless steel base material by means of an end mill to form tubs and channels in the base material, and screwing a stainless plate to the base material. A rod-like electric heater was embedded in the base and fluid was heated.
In the example 2, a heat exchanging apparatus was manufacture by forming tubs and channels in a stainless cylinder surface by means of a lathe and an end mill and tightly fitting this cylinder into a cylindrical stainless pipe.
A hole was opened at a central axis and a rod-like heater was embedded in the hole so that fluid could be heated.
In both of the heat exchanging apparatuses, nitrogen gas was caused to flow as fluid, and the heat exchange efficiency was equal to or more than 80% on the basis of a relationship between the consumed power of the heater and the flow rate and temperature of the nitrogen gas heated and discharged. Since the structure caused the gas to impinge, the heat exchange efficiency became higher as the flow rate increased because in principle the heat exchange efficiency became higher as the flow rate increases.
The present invention inexpensively provides small and light parts for producing a huge amount of gas or liquid heated to high temperature. The field of application of the present invention can be drying of a printed material, a downsized heating-cooling combination appliance, heat exchange in a heating and cooling apparatus for a material containing a toxic substance or a radioactive substance or for a corrosive material, high-speed generation of high-temperature steam, a heating vaporizing apparatus for waste, melting of industrial waste plastic, or the like.
The present invention is also advantageously applied to the technique of forming a solar battery or a flat panel display (FPD) on a large substrate such as a glass substrate inexpensively by heating film deposition.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-237211 | Nov 2013 | JP | national |
