Patent Application
20220349664
The present invention relates to a heat exchanger cleaning system and a heat exchanger cleaning method, and more particularly, to a heat exchanger cleaning system with improved cleaning efficiency of a target rotating body, which is a component of a heat exchanger, as well as a heat exchanger cleaning method.
Nitrogen oxides (NOx) are included in exhaust gas discharged from combustion engines such as boilers, and these nitrogen oxides cause pollution so that these need to be removed before being discharged into the atmosphere. As a method for removing nitrogen oxides contained in exhaust gas, selective catalytic reduction (SCR) is mainly used. Meanwhile, when the exhaust gas passes through an SCR device, a concentration of sulfur trioxide in the exhaust gas increases, and ammonia (NH3) used in the catalytic reaction of the SCR device may react with sulfur trioxide and moisture (H2O) included in the exhaust gas to form ammonium hydrogen sulfate (NH4HSO4)—also called ammonium bisulfate. When the heat exchanger (gas-air heater (GAH) or gas-gas heater (GGH)) installed at the rear of the SCR device is operated continuously for a long time, foreign substances (reactants) including ammonium hydrogen sulfate would be accumulated in the heat exchanger, hence causing a problem of deteriorating ventilation in the heat exchanger.
In order to solve this problem, a heat exchanger cleaning device (soot blower) may be installed in the upper and/or lower part of the heat exchanger so as to remove foreign substances accumulated in the heat exchanger.
Conventionally, a method of removing foreign substances by injecting high-temperature steam or high-pressure water into the heat exchanger has been used. However, when high-pressure water is injected, the concentration of moisture in the exhaust gas increases and causes a problem of deteriorating the performance and lifespan of a device installed at the rear end of the heat exchanger (for example, a dust collector). Therefore, it is necessary to separately provide a device for recovering a large amount of wastewater generated due to the above method.
Korean Patent Registration No. 10-1555227 (Patent Document 1) discloses a dry cleaning method using dry ice pellets instead of spraying high-pressure water. This method is effective when only ammonium hydrogen sulfate is present as a foreign substance, but it is difficult to remove foreign substances comprising a combination of different components due to deterioration in fuel quality, etc. Specifically, when the foreign substance is frozen due to low atmospheric temperature, there is a problem that foreign substances cannot be effectively removed by only the above cleaning method.
Korean Patent Registration No. 10-1387024 (Patent Document 2) discloses a method of removing foreign substances from the inside of the heat exchanger by injecting hot steam and dry ice pellets inside the heat exchanger. According to this method, high-temperature steam and dry ice pellets are injected in a flow direction of air supply and/or exhaust gas from a cleaning device disposed on the inlet side of the heat exchanger. However, since the temperature at the inlet of the heat exchanger into which the exhaust gas flows is high, a sublimation speed of the dry ice pellets may be accelerated and therefore cleaning effects may be reduced. If the high-temperature steam injected from the cleaning device disposed at the inlet of the heat exchanger into which the supplied air is introduced into the boiler, damage to the boiler may occur and thermal efficiency of the boiler may also be reduced. In addition, even if hot steam and dry ice pellets are sprayed, the target is still rotating and a cleaner is also moving, hence causing a problem that cleaning effects at a specific target point may be deteriorated.
(Patent Document 1) KR10-1555227 B
(Patent Document 2) KR10-1387024 B
An object of the present invention is to provide a heat exchanger cleaning system with improved cleaning efficiency of a target rotating body (“target rotor”), which is a component of a heat exchanger, as well as a heat exchanger cleaning method.
The heat exchanger cleaning system according to an embodiment of the present invention may include: a target rotor that rotates around a virtual rotation axis extending in one direction; a first inlet positioned above the target rotor; a first outlet positioned below the target rotor and opposed to the first inlet; a second inlet positioned below the target rotor and spaced apart from the first outlet; a second outlet positioned above the target rotor and opposed to the second inlet; and a first soot blower positioned in an inner space of the first inlet.
The first inlet may be a passage through which a first gas is introduced toward the target rotor. The first outlet may be a passage through which the first gas passing through the target rotor is discharged. The second inlet may be a passage through which a second gas having a temperature lower than that of the first gas is introduced toward the target rotor. The second outlet may be a passage through which the second gas passing through the target rotor is discharged.
The first soot blower may include a first nozzle through which a first material is injected toward the target rotor, and a second nozzle through which a second material is injected toward the target rotor. The second nozzle may be positioned at a predetermined interval from the first nozzle.
A first distance of the first nozzle spaced apart from the virtual rotation axis of the target rotor may be substantially the same as a second distance of the second nozzle spaced apart from the virtual rotation axis of the target rotor.
Each of the first nozzle and the second nozzle may be located on the circumference of a concentric circle of the target rotor, and may be positioned to face each of target points spaced apart from each other.
The first material and the second material may be sequentially injected onto one target point of the target rotor when the target rotor rotates around the virtual rotation axis.
The first material may be high-temperature steam and the second material may be dry ice pellets.
The first soot blower may be disposed adjacent to the second outlet.
The heat exchanger cleaning system according to an embodiment of the present invention may further include a second soot blower positioned in an inner space of the first outlet.
The second soot blower may include a third nozzle through which the first material is injected toward the target rotor, and a fourth nozzle through which the second material is injected toward the target rotor. The fourth nozzle may be positioned at a predetermined interval from the third nozzle.
A third distance of the third nozzle spaced apart from the virtual rotation axis of the target rotor may be substantially the same as a fourth distance of the fourth nozzle spaced apart from the virtual rotation axis of the target rotor.
Each of the third nozzle and the fourth nozzle may be located on the circumference of a concentric circle of the target rotor, and may be positioned to face each of target points spaced apart from each other.
The second soot blower may be disposed adjacent to the second inlet.
The heat exchanger cleaning system according to an embodiment of the present invention may further include a driving unit for adjusting the positions of the first soot blower and the second soot blower.
The driving unit may move the first soot blower and the second soot blower to move away from or closer to the virtual rotation axis of the target rotor. The driving unit may arrange the first soot blower such that the first distance and the second distance are substantially equal to each other by adjusting a spaced distance between the first and second nozzles. The driving unit may arrange the second soot blower such that the third distance and the fourth distance are substantially equal to each other by adjusting a spaced distance between the third and fourth nozzles.
While the target rotor is rotating, the first material and the second material may be continuously sprayed simultaneously.
A heat exchanger cleaning method using the above heat exchanger cleaning system according to an embodiment of the present invention may include: positioning the first soot blower in the inner space of the first inlet; injecting the first material through the first nozzle of the first soot blower and, simultaneously, injecting the second material through the second nozzle of the first soot blower toward the target rotor during rotation of the target rotor; and removing foreign substances since the first material and the second material sequentially reach one point of the target rotor.
The first distance of the first nozzle spaced apart from the virtual rotation axis of the target rotor may be substantially the same as the second distance of the second nozzle spaced apart from the virtual rotation axis of the target rotor.
The first material may be high-temperature steam, and the second material may be dry ice pellets.
In the step of positioning the first soot blower, the first soot blower may be disposed adjacent to the second outlet. Further, each of the first nozzle and the second nozzle may be positioned on the circumference of a concentric circle of the target rotor, and may be positioned to face each of target points that are spaced apart from each other.
The heat exchanger cleaning method according to an embodiment of the present invention may further include: positioning a second soot blower in an inner space of the first outlet; and injecting the first material through the third nozzle of the second soot blower and, simultaneously, injecting the second material through the fourth nozzle of the second soot blower toward the target rotor during rotation of the target rotor.
In this regard, a third distance of the third nozzle spaced apart from the virtual rotation axis of the target rotor may be substantially the same as a fourth distance of the fourth nozzle spaced apart from the virtual rotation axis of the target rotor.
In the step of positioning the second soot blower, the second soot blower may be disposed adjacent to the second inlet. Further, each of the third nozzle and the fourth nozzle may be positioned on the circumference of a concentric circle of the target rotor, and may be positioned to face each of target points that are spaced apart from each other.
The heat exchanger cleaning method according to an embodiment of the present invention may further include: adjusting the position of each of the first soot blower and the second soot blower by a driving unit connected to the first soot blower and the second soot blower during rotation of the target rotor.
In the step of adjusting the position of each of the first soot blower and the second soot blower, each of the first soot blower and the second soot blower may move away from or closer to the virtual rotation axis of the target rotor. Further, a spaced distance between the first nozzle and the second nozzle of the first soot blower may be adjusted so that the first distance and the second distance are substantially equal to each other. Further, a spaced distance between the third nozzle and the fourth nozzle of the second soot blower may be adjusted so that the third distance and the fourth distance are substantially equal to each other.
The heat exchanger cleaning system and the heat exchanger cleaning method according to an embodiment of the present invention can effectively remove foreign substances from the target rotor since high-temperature steam and dry ice pellets are injected at the same point of the target rotor.
The present invention may include various alterations and modifications, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form of disclosure. Instead, it is to be understood as including all changes, equivalents, and substitutes included in the spirit and scope of the present invention.
In the present application, terms such as “include” or “have” are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that possibility for the presence or addition of elements, numbers, steps, actions, components, parts or combinations thereof does not preclude in advance. Further, if a component (or part) is said to be “above” (or “on”) another component (or part), this means not only that a component is “directly above” the other component (or part) but also that another component may be present therebetween. Likewise, if a component (or part) is said to be “below” (or “under”) another component (or part), this means not only that a component is “directly below” the other component (or part) but also that another component may be present therebetween. Further, the “above” (or “on”) and “below” (or “under”) refer to the position of a horizontal heat exchanger as viewed from the side (which may be referred to as the front side or the rear side depending on the point of view) (See
In describing each drawing, similar reference numerals have been used for similar elements. Terms such as first and second may be used to describe various elements, but elements should not be limited by such terms. The terms are only used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Singular expressions include multiple expressions unless the context clearly indicates otherwise.
Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.
First, referring to
The target rotor 10 may rotate around a virtual rotation axis 1 extending in a first direction DR1. The target rotor 10 is a device for mutually exchanging heat between high-temperature gas and low-temperature gas that pass through the target rotor 10 while rotating around the virtual rotation axis 1. For example, the above device may be an air preheater or a gas preheater.
The target rotor 10 may include an outer frame 11, an inner frame 13, and a heat exchange plate 15.
The outer frame 11 may have a predetermined height extending in the first direction DR1, and may be an annular frame that cross the first direction DR1 and have an inner space corresponding to a plane formed in a second direction DR2 and a third direction DR3 crossing each other.
The inner frame 13 may be a frame that divides the inner space of the outer frame 11 in a radial direction and a circumferential direction.
The heat exchange plate 15 may be provided in an area partitioned by the outer frame 11 and the inner frame 13. The heat exchange plate 15 may be a lattice-shaped or corrugated metal plate.
The first inlet 20 may be positioned above the target rotor 10. The first inlet 20 may be a passage through which the first gas G1 is introduced toward the target rotor 10. Herein, the first inlet 20 may be connected to a facility (not shown) such as a boiler, wherein the first gas G1 may be a high temperature gas discharged from the inside of the facility (not shown). For example, the first gas G1 may be substantially exhaust gas.
The first outlet 23 may be disposed under the target rotor 10. The first outlet 23 may be positioned opposite to the first inlet 20 with the target rotor 10 interposed therebetween. The first outlet 23 may be a passage through which the first gas G1 introduced through the first inlet 20 passes through the target rotor 10 and then is discharged to the outside. A temperature of the first gas G1 discharged through the first outlet 23 may be lower than a temperature of the first gas G1 introduced through the first inlet 20.
The second inlet 30 may be disposed under the target rotor 10. The second inlet 30 may be positioned to be spaced apart from the first outlet 23. The second inlet 30 may be a passage through which the second gas G2 is introduced toward the target rotor 10. Herein, the second gas G2 is a gas having a temperature lower than that of the first gas G1, and may be, for example, air supplied from the outside.
The second outlet 33 may be disposed on top of the target rotor 10. The second outlet 33 may be positioned to be spaced apart from the first inlet 20. The second outlet 33 may be positioned to face the second inlet 30 with the target rotor 10 interposed therebetween. The second outlet 33 may be a passage through which the second gas G2 introduced through the second inlet 30 passes through the target rotor 10 and then is discharged. A temperature of the second gas G2 discharged through the second outlet 33 may be higher than a temperature of the second gas G2 introduced through the second inlet 30. Further, the temperature of the second gas G2 discharged through the second outlet 33 may be lower than the temperature of the first gas G1 introduced through the first inlet 20.
The second outlet 33 may be connected to a facility (not shown), and in this case, the second gas G2 may be supplied into the facility (not shown).
The soot blower 100 may be a device for cleaning the target rotor 10 and may be positioned in a region above and/or below the target rotor 10.
In an embodiment of the present invention, the soot blower 100 may include a first soot blower 101 and a second soot blower 102.
The first soot blower 101 may be positioned in an area above the target rotor 10 and may be disposed in an inner space of the first inlet 20.
The second soot blower 102 may be positioned in a region under the target rotor 10 and may be disposed in an inner space of the first outlet 23. Further, the second soot blower 102 may be positioned to face the first soot blower 101.
The first soot blower 101 and the second soot blower 102 will be described in more detail later.
The driving unit 50 may adjust the positions of the first soot blower 101 and the second soot blower 102 together/simultaneously or respectively. The driving unit 50 may adjust the positions of the first soot blower 101 and the second soot blower 102 to move away from or closer to the virtual rotation axis 1. In this case, the first soot blower 101 and the second soot blower 101 may maintain a distance spaced apart from the target rotor 10 by a predetermined interval, while moving in a direction parallel to a plane formed by the second direction DR2 and the third direction DR3.
First, referring to
The first soot blower 101 may include a first supply unit 110 to supply a first material M1 and a second supply unit 120 to supply a second material M2. In one embodiment of the present invention, the first material M1 may be high-temperature steam, and the second material M2 may be dry ice pellets.
The first supply unit 110 may include a first supply path 111 through which the first material M1 moves and a first nozzle 113 through which the first material M1 is injected. The first nozzle 113 may be positioned to be spaced apart from the virtual rotation axis 1 by a first distance D1.
The second supply unit 120 may include a second supply path 121 through which the second material M2 moves and a second nozzle 123 through which the second material M2 is injected. The second nozzle 123 may be positioned at a predetermined interval from the first nozzle 113. The second nozzle 123 may be positioned to be spaced apart from the virtual rotation axis 1 by a second distance D2.
In an embodiment of the present invention, the first nozzle 113 and the second nozzle 123 are located on a plane substantially parallel to another plane formed by the second direction DR2 and the third direction DR3, respectively, the first distance D1 and the second distance D2 may be substantially equal to each other. That is, the first nozzle 113 and the second nozzle 123 are disposed on the circumference of a concentric circle of the target rotor 10, respectively, and may be positioned to face each of target points spaced apart from each other.
While the target rotor 10 is rotating, the first material M1 and the second material M2 may be continuously injected simultaneously. Accordingly, on one concentric circle of the target rotor 10, the second material M2 can sequentially reach at a point where the first material M1 was injected.
The first soot blower 101 may be disposed adjacent to a second region R2 that is an area on the target rotor 10, in which the second outlet 33 is disposed.
When the first gas G1 flows into the first inlet 20 in a high-temperature state, a temperature of an inner space of the first inlet 20 can be maintained in a high-temperature state similar to that of the first gas G1. When the first soot blower 101 injects the first material M1 and the second material M2 from the inner space of the first inlet 20, it may be difficult for the first material M1 and the second material M2 to reach the target rotor 10 due to the temperature of the inner space of the first inlet 20. In particular, when the second material M2 is provided as dry ice pellets, the dry ice pellets may be sublimated by the temperature of the inner space of the first inlet 20 in a high temperature state.
Accordingly, the first soot blower 101 may be disposed in a place where a temperature is relatively low even within the first region R1. That is, the first soot blower 101 is located as close to the second region R2 as possible even within the first region R1, so that an amount of sublimation of the dry ice pellets may be reduced as much as possible.
Referring to
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The second soot blower 102 may include a third supply unit 130 to supply the first material M1 and a fourth supply unit 140 to supply the second material M2.
The third supply unit 130 may include a third supply path 131 through which the first material M1 moves and a third nozzle 133 through which the first material M1 is injected. The third nozzle 133 may be positioned to be spaced apart from the virtual rotation axis 1 by a third distance D3.
The fourth supply unit 140 may include a fourth supply path 141 through which the second material M2 moves and a fourth nozzle 143 through which the second material M2 is injected. The fourth nozzle 143 may be positioned at a predetermined interval from the third nozzle 133. The fourth nozzle 143 may be positioned to be spaced apart from the virtual rotation shaft 1 by a fourth distance D4.
In an embodiment of the present invention, the third nozzle 133 and the fourth nozzle 143 are located on a plane substantially parallel to another plane formed by the second direction DR2 and the third direction DR3, respectively, the third distance D3 and the fourth distance D4 may be substantially equal to each other. That is, the third nozzle 133 and the fourth nozzle 143 are respectively disposed on the circumference of a concentric circle of the target rotor 10, and may be positioned to face each other and face target points located spaced apart from each other
While the target rotor 10 is rotating, the first material M1 and the second material M2 may be continuously injected simultaneously. Accordingly, on one concentric circle of the target rotor 10, the second material M2 may sequentially reach a point where the first material M1 was injected.
The second soot blower 102 may be positioned under the target rotor 10 and adjacent to a fourth region R4, which is an area in which the second inlet 30 is disposed.
A temperature of the first gas G1 discharged through the first outlet 23 after passing through the target rotor 10 is lower than a temperature of the first gas G1 introduced through the first inlet 20, but may be higher than a temperature of the second gas G2 introduced through the second inlet 30.
Accordingly, the second soot blower 102 is positioned as close to the fourth region R4 as possible within the third region R3, whereby an amount of subliming the dry ice pellets as the second material M2 can be reduced as much as possible.
Further, the second soot blower 102 may inject a larger amount of the first material M1 and the second material M2 than the first soot blower 101.
As the first material M1 and the second material M2 are injected in a direction opposite to the direction in which the first gas G1 is discharged through the first outlet 23, it may be difficult for the first material M1 and the second material M2 injected from the second blower 102 to reach the target rotor 10.
At this time, since the amount of the first material M1 and the second material M2 injected from the second soot blower 102 are increased, it is possible to easily remove the foreign substances on a lower portion of the target rotor 10.
Referring to
Conventionally, the second soot blower 102 was positioned to overlap the fourth region R4. However, in this case, the first material and the second material M2 injected from the second soot blower 102 were introduced into the facility (not shown), hence causing a problem of deteriorating facility characteristics. On the other hand, in an embodiment of the present invention, the second soot blower 102 may be positioned to overlap the third region R3, therefore, it is possible to prevent the first material M1 and the second material M2 injected from the second soot blower 102 from flowing into the facility (not shown). In other words, according to the present invention, for example, the soot blower is not disposed in the second region R2 and the fourth region R4 where air supplied from the outside is introduced into and then pass through the regions.
Referring to
Referring to
When the first material M1 and the second material M2 sequentially reach one point of the target rotor 10, foreign substances of the target rotor 10 may be easily removed.
First, the first material M1 may reach a first point P1 of the target rotor 10. As the target rotor 10 rotates in a counterclockwise direction, the first point P1 migrates in the counterclockwise direction. Further, when the first material M1 reaches a new second point P2, the second material M2 may reach the first point P1.
Accordingly, it is possible to easily remove foreign substances from the first point P1 where the first material M1 and the second material M2 sequentially reached.
Referring to
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Referring to
Referring to
Hereinafter, a heat exchanger cleaning method for cleaning the target rotor 10 using the heat exchanger cleaning system will be described. For convenience of explanation, a description that is duplicated with the description of the above-described heat exchanger cleaning system will be omitted.
The heat exchanger cleaning method according to an embodiment of the present invention may include: positioning the first soot blower 101 in the inner space of the first inlet 20; injecting the first material M1 through the first nozzle 113 of the first soot blower 101 and, simultaneously, injecting the second material M2 through the second nozzle 123 of the first soot blower 101 toward the target rotor during rotation of the target rotor 10; and removing foreign substances since the first material M1 and the second material M2 sequentially reach one point of the target rotor 10.
In this regard, the first distance D1 of the first nozzle 113 spaced apart from the virtual rotation axis 1 of the target rotor 10 may be substantially the same as the second distance D2 of the second nozzle 123 spaced apart from the he virtual rotation axis 1 of the target rotor 10.
The first material M1 may be high-temperature steam, and the second material M2 may be dry ice pellets.
In the step of positioning the first soot blower 101, the first soot blower 101 may be disposed adjacent to the second outlet 33 above the target rotor 10.
The first distance D1 of the first nozzle 113 spaced apart from the virtual rotation axis 1 of the target rotor 10, may be substantially the same as the second distance D2 of the second nozzle 123 spaced apart from the virtual rotation axis 1 of the target rotor 10.
The heat exchanger cleaning method according to an embodiment of the present invention may further include: positioning the second soot blower 102 in the inner space of the first outlet 23 under the target rotor 10; and injecting the first material M1 through the third nozzle 133 of the second soot blower 102 and, simultaneously, injecting the second material M2 through the fourth nozzle 143 of the second soot blower 102 toward the target rotor 10 during rotation of the target rotor 10.
The third distance D3 of the third nozzle 133 spaced apart from the virtual rotation axis 1 of the target rotor 10 may be substantially the same as the fourth distance D4 of the fourth nozzle 143 spaced apart from the virtual rotation axis 1.
In the step of positioning the second soot blower 102, the second soot blower 102 may be disposed adjacent to the second inlet 30 under the target rotor 10.
The heat exchanger cleaning method according to an embodiment of the present invention may further include: adjusting the position of each of the first soot blower 101 and the second soot blower 102 by a driving unit 50 connected to the first soot blower 101 and the second soot blower 102 during rotation of the target rotor 10.
Each of the first soot blower 101 and the second soot blower 102 may move away from or closer to the virtual rotation axis 1 of the target rotor 10. At this time, a spaced distance between the first nozzle 113 and the second nozzle 123 of the first soot blower 101 may be appropriately adjusted such that the first distance D1 and the second distance D2 are substantially equal to each other, and similarly, a spaced distance between the third nozzle 133 and the fourth nozzle 143 of the second soot blower 102 may be appropriately adjusted such that the third distance D3 and the fourth distance D4 are substantially equal to each other.
As such, although the above description was provided with reference to the preferred embodiments of the present invention, it would be understood by those skilled in the art or those having ordinary knowledge in the relevant technical field that various modifications and alterations of the present invention could be made within the scope of the present invention without departing from the spirit and scope of the invention described in the appended claims later.
Therefore, the technical scope of the present invention should not be limited to the content described in the detailed description of the specification, but should be determined only by the claims.
10: target rotor 20: first inlet
23: first outlet 30: second inlet
33: second outlet 101: first soot blower
102: second soot blower 50: driving unit
113: first nozzle 123: second nozzle
133: third nozzle 143: fourth nozzle
M1: first material M2: second material
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2019-0090749 | Jul 2019 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2019/011806 | 9/11/2019 | WO |
