Boiler flue directly connected flue gas waste heat recovery heat exchanger

Abstract

The invention relates to the technical field of heat exchangers, in particular to a boiler flue direct connection flue gas waste heat recovery heat exchanger which comprises a box body and a heat exchange device. The heat exchange device comprises a frame body and a plurality of heat exchange plates, and the heat exchange plates define a plurality of hot air cavities and a plurality of cold air cavities on the frame body. A plurality of heat exchange pipes are arranged on each heat exchange plate, each heat exchange pipe comprises a pipe body and a sponge layer, and the sponge layers are wound on the pipe bodies. According to the boiler flue directly-connected flue gas waste heat recovery heat exchanger, the heat exchange device is arranged, the heat exchange pipes are arranged on the heat exchange plates, flue gas flows in the hot air cavity after entering the hot air cavity and passes through the sponge layers on the heat exchange pipes, at the moment, water vapor in the flue gas flows to the cold air cavity along the sponge layers, and the waste heat of the flue gas is recovered. And on the basis of heat exchange of the heat exchange plates, auxiliary heat exchange is carried out in combination with the heat exchange pipes.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchangers, and in particular to a flue gas waste heat recovery heat exchanger directly connected to a boiler flue. Background Art

[0002] Plate heat exchanger is a commonly used waste heat recovery device. It realizes heat exchange by stacking multiple thin stainless steel plates to form countless microchannels. This heat exchanger has the advantages of compact structure, high temperature resistance, corrosion resistance, etc., and is widely used in all walks of life. When recovering boiler flue gas, by installing the waste heat recovery device at the boiler flue outlet, the waste heat of the flue gas enters one side of the waste heat recovery device from the flue gas inlet, and is sent out from the flue gas outlet after the waste heat recovery device absorbs heat and cools down. Normal temperature air is blown into the air inlet of the recovery device by the blower, enters the heating surface of the waste heat recovery device, and is sent out from the air outlet after being heated by the waste heat recovery device. The sent hot air can be used for flame retardant or drying materials. However, in actual use, although the heat exchange capacity of the heat exchanger is large, its heat exchange efficiency needs to be improved. Summary of the invention

[0003] The present invention provides a flue gas waste heat recovery heat exchanger directly connected to a boiler flue, so as to solve the problem that when the existing heat exchanger is in use, although the heat exchange amount of the heat exchanger is relatively large, the heat exchange efficiency thereof needs to be improved.

[0004] A boiler flue directly connected to flue gas waste heat recovery heat exchanger of the present invention adopts the following technical scheme: a boiler flue directly connected to flue gas waste heat recovery heat exchanger, comprising a box body and a heat exchange device, the heat exchange device is installed in the box body; the heat exchange device comprises a frame body and a plurality of heat exchange plates, the plurality of heat exchange plates are arranged in sequence on the frame body along a first direction, the first direction is a horizontal direction, the plurality of heat exchange plates define a plurality of hot air chambers and a plurality of cold air chambers arranged in sequence along the first direction on the frame body, and the hot air chambers and the cold air chambers are alternately distributed in sequence in the first direction; the hot air chambers are connected in a second direction, the second direction is a vertical direction, and flue gas flows in the hot air chambers, The cold air cavity is connected in a third direction, which is horizontal and perpendicular to the first direction, and room temperature gas flows in the cold air cavity; a plurality of heat exchange tubes are arranged on each heat exchange plate, and the plurality of heat exchange tubes are arranged in sequence along the second direction on the corresponding heat exchange plate, and the heat exchange tubes pass through the hot air cavity along the first direction and extend into the cold air cavity adjacent to the hot air cavity; the heat exchange tube includes a tube body and a sponge layer; the tube body is columnar, and a through hole is coaxially opened on the tube body, and the two ends along the axial direction of the tube body are respectively called the head end and the tail end, one end of the sponge layer is installed on the head end of the tube body, and the other end passes through the through hole and is wound around the tail end of the tube body.

[0005] Furthermore, a cold end inlet, a cold end outlet, a hot end inlet and a flue connection port are provided on the box body; the hot end inlet and the flue connection port are arranged face to face along the second direction on the box body, and the hot end inlet is connected with the flue connection port through a hot air cavity; the cold end inlet and the cold end outlet are arranged face to face along the third direction on the box body, and the cold end inlet is connected with the cold end outlet through a cold air cavity.

[0006] Furthermore, the tube body is arranged at an angle, and the part of the tube body that is in the hot air cavity is called the first tube section, and the part of the tube body that is in the cold air cavity is called the second tube section; the two ends of the first tube section along the axial direction of the tube body are respectively called the first end and the second end, the first end is located on the side of the second end that is away from the second tube section in the axial direction of the tube body, the first end is located on the side of the second end that is close to the hot end inlet in the second direction, and the sponge layer located on one side of the first tube section is in contact with the heat exchange plate, and two water collecting plates are arranged on one side of the hot end inlet, both of which are located in the hot air cavity, and the two water collecting plates are respectively arranged on the heat exchange plate where the tube body is located and another heat exchange plate that is adjacent to the heat exchange plate in the first direction.

[0007] Furthermore, a water collecting trough is provided on the water collecting plate, and the lower end of the water collecting plate is connected to a water pipe.

[0008] Furthermore, the interior of the tube body is hollow and has a corrugated section, which is located on one side of the second tube section and in the cold air cavity. The interior of the tube body is filled with an expansion fluid that can expand when heated.

[0009] Furthermore, the inclination directions of the tubes on every two heat exchange plates adjacently arranged in the first direction are opposite.

[0010] Furthermore, a sleeve is arranged inside the tube body, and the sleeve is located in the through hole and is coaxial with the through hole.

[0011] Furthermore, protective films are provided at both ends of the through hole.

[0012] Furthermore, a heat-insulating layer is provided between the heat exchange device and the box body, and heat-insulating cotton is provided on the heat-insulating layer.

[0013] Furthermore, the heat exchange tube is installed on the heat exchange plate through a mounting plate.

[0014] The beneficial effects of the present invention are as follows: a boiler flue directly connected flue gas waste heat recovery heat exchanger of the present invention is provided with a heat exchange device, and a heat exchange tube is provided on the heat exchange plate. When in use, the flue gas is passed into the hot air chamber. After entering the hot air chamber, the flue gas will flow in the hot air chamber and pass through the sponge layer on the heat exchange tube. At this time, the water vapor in the flue gas will follow the sponge layer to the cold air chamber, and liquefy into condensed water in the cold air chamber. In this process, latent heat is released, and part of the liquefied condensed water will be carried away by the air in the cold air chamber. In this process, the condensed water evaporates and takes away more heat, so that the waste heat of the flue gas is recovered. On the basis of heat exchange on the heat exchange plate, auxiliary heat exchange is performed in combination with the heat exchange tube, thereby improving the heat exchange efficiency of the heat exchange device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a boiler flue directly connected to a flue gas waste heat recovery heat exchanger of the present invention; Figure 2 A top view of the overall structure of an embodiment of a boiler flue directly connected to flue gas waste heat recovery heat exchanger of the present invention; Figure 3 for Figure 2 Sectional view along AA; Figure 4 It is a schematic diagram of a heat exchange device of an embodiment of a boiler flue directly connected to a flue gas waste heat recovery heat exchanger of the present invention; Figure 5 It is a front view of a heat exchange device of an embodiment of a boiler flue directly connected to a flue gas waste heat recovery heat exchanger of the present invention; Figure 6 for Figure 5 Cross-sectional view along the middle line BB; Figure 7 It is a schematic diagram of a partial structure of a heat exchange device of an embodiment of a boiler flue directly connected to a flue gas waste heat recovery heat exchanger of the present invention; Figure 8 for Figure 7 Enlarged view of point C in the middle; Fig. 9 A distribution diagram of multiple heat exchange tubes on a heat exchange plate of an embodiment of a flue gas waste heat recovery heat exchanger directly connected to a boiler flue of the present invention; Fig.10A schematic diagram of a heat exchange tube and a mounting plate of an embodiment of a flue gas waste heat recovery heat exchanger directly connected to a boiler flue of the present invention; Fig.11 A schematic diagram of a heat exchange tube of an embodiment of a flue gas waste heat recovery heat exchanger directly connected to a boiler flue of the present invention; Fig.12 for Fig.11 Sectional view along the middle edge at DD; Fig.13 It is a cross-sectional view of a pipe body of an embodiment of a flue gas waste heat recovery heat exchanger directly connected to a boiler flue according to the present invention.

[0017] In the figure: 100, box body; 110, cold end inlet; 120, cold end outlet; 130, hot end inlet; 140, flue connection port; 150, insulation layer; 160, water collecting plate; 170, water pipe; 200, heat exchange device; 210, frame; 220, heat exchange plate; 230, hot air chamber; 240, cold air chamber; 250, heat exchange tube; 251, tube body; 252, sponge layer; 253, corrugated section; 254, sleeve; 255, protective film; 260, mounting plate. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] An embodiment of a boiler flue directly connected to a flue gas waste heat recovery heat exchanger of the present invention is as follows: Figures 1 to 13 shown.

[0020] A boiler flue directly connected flue gas waste heat recovery heat exchanger comprises a box body 100 and a heat exchange device 200 , wherein the heat exchange device 200 is installed in the box body 100 .

[0021] The heat exchange device 200 includes a frame 210 and a plurality of heat exchange plates 220. The plurality of heat exchange plates 220 are sequentially arranged on the frame 210 along a first direction, which is a horizontal direction. The plurality of heat exchange plates 220 define a plurality of hot air chambers 230 and a plurality of cold air chambers 240 sequentially arranged along the first direction on the frame 210, and the hot air chambers 230 and the cold air chambers 240 are alternately distributed in the first direction. The hot air chambers 230 are connected in a second direction, which is a vertical direction, and smoke is passed through the hot air chambers 230. The cold air chambers 240 are connected in a third direction, which is a horizontal direction and perpendicular to the first direction. Normal temperature gas is passed through the cold air chambers 240. The cold air chambers 240 and the hot air chambers 230 are independent of each other.

[0022] See attached Figure 1 As shown, the first direction is Figure 1 The second direction is the direction indicated by the X axis. Figure 1 The third direction is the direction indicated by the Y axis. Figure 1 The direction is shown by the Z axis.

[0023] A plurality of heat exchange tubes 250 are arranged on each heat exchange plate 220. The plurality of heat exchange tubes 250 are arranged in sequence along the second direction on the corresponding heat exchange plate 220. The heat exchange tubes 250 pass through the hot air cavity 230 along the first direction and extend into the cold air cavity 240 adjacent to the hot air cavity 230. The heat exchange tube 250 includes a tube body 251 and a sponge layer 252. The tube body 251 is columnar, and a through hole is coaxially opened on the tube body 251. The two ends along the axis direction of the tube body 251 are respectively referred to as the head end and the tail end. One end of the sponge layer 252 is installed at the head end of the tube body 251, and the other end passes through the through hole and is wound around the tail end of the tube body 251.

[0024] Specifically, the heat exchange tube 250 is mounted on the heat exchange plate 220 through the mounting plate 260 .

[0025] In this embodiment, a heat exchange device 200 is provided, and a heat exchange tube 250 is provided on the heat exchange plate 220. When in use, the flue gas is passed into the hot air chamber 230. After entering the hot air chamber 230, the flue gas will flow in the hot air chamber 230 and pass through the sponge layer 252 on the heat exchange tube 250. The water vapor in the flue gas will follow the sponge layer 252 to the cold air chamber 240, and will be liquefied into condensed water in the cold air chamber 240. In this process, latent heat is released, and part of the liquefied condensed water will be carried away by the air in the cold air chamber 240. In this process, the condensed water evaporates and takes away more heat, thereby recovering the waste heat of the flue gas. On the basis of heat exchange of the heat exchange plate 220, auxiliary heat exchange is performed in combination with the heat exchange tube 250, thereby improving the heat exchange efficiency of the heat exchange device 200.

[0026] In this embodiment, the box body 100 is provided with a cold end inlet 110, a cold end outlet 120, a hot end inlet 130 and a flue connection port 140. The hot end inlet 130 and the flue connection port 140 are arranged face to face along the second direction on the box body 100, and the hot end inlet 130 is connected with the flue connection port 140 through the hot air cavity 230. The hot end inlet 130 is connected with the boiler flue, and the boiler flue is used to introduce flue gas into the hot air cavity 230. A chimney is arranged at the flue connection port 140 to facilitate the discharge of flue gas after heat exchange. The cold end inlet 110 and the cold end outlet 120 are arranged face to face along the third direction on the box body 100. The cold end inlet 110 is connected to the cold end outlet 120 through the cold air cavity 240. The cold end inlet 110 is connected to an external fan, and the fan is used to transport room temperature gas to the cold end inlet 110. The room temperature gas can enter the cold air cavity 240 from the cold end inlet 110 and be discharged from the cold end outlet 120 after passing through the cold air cavity 240.

[0027] Furthermore, an economizer is connected to the cold end outlet 120. By connecting the economizer to the cold end outlet 120, water can be heated. If only the economizer is connected, only water can be heated, and the effect is relatively simple. Alternatively, a boiler can also be connected to the cold end outlet 120 to heat or dry materials.

[0028] In this embodiment, a heat-insulating layer 150 is provided between the heat exchange device 200 and the box body 100, and heat-insulating cotton is provided on the heat-insulating layer 150. The heat-insulating layer 150 and the heat-insulating cotton are provided to prevent heat loss.

[0029] In this embodiment, the tube body 251 is arranged obliquely, and the part of the tube body 251 in the hot air chamber 230 is called the first tube section, and the part of the tube body 251 in the cold air chamber 240 is called the second tube section. The two ends of the first tube section along the axis direction of the tube body 251 are respectively called the first end and the second end, the first end is located on the side of the second end away from the second tube section in the axis direction of the tube body 251, the first end is located on the side of the second end close to the hot end inlet 130 in the second direction, and the sponge layer 252 located on one side of the first tube section abuts against the heat exchange plate 220, and two water collecting plates 160 are arranged on one side of the hot end inlet 130, both of which are located in the hot air chamber 230, and the two water collecting plates 160 are respectively arranged on the heat exchange plate 220 where the tube body 251 is located and another heat exchange plate 220 arranged adjacent to the heat exchange plate 220 in the first direction. A space is left between the two water collecting plates 160 to allow smoke to flow.

[0030] Specifically, a water collecting trough is provided on the water collecting plate 160 , and the lower end of the water collecting plate 160 is connected to the water pipe 170 , and the water pipe 170 is in communication with the water collecting trough.

[0031] The heat exchange tube 250 is tilted and the first end of the first tube section is located on the side of the second end thereof close to the hot end inlet 130 in the second direction, that is, the first end is located below the second end. When in use, the condensed water after liquefaction through the cold air chamber 240 can flow back to the hot air chamber 230 through the sponge layer 252, flow downward along the surface of the heat exchange plate 220 in the hot air chamber 230, and finally enter the water collecting tank and be led out from the water pipe 170, so as to prevent the condensed water from flowing back to the boiler flue and causing corrosion. The structure is simple, and the transition flue and other structures connecting the device and the boiler flue are omitted, so as to reduce the equipment installation investment cost. Moreover, part of the carbon dioxide and nitrogen oxides in the flue gas flow away with the condensed water to avoid entering the atmosphere, thereby reducing the emission of polluting gases.

[0032] In this embodiment, the tube body 251 is hollow inside and has a corrugated section 253 . The corrugated section 253 is located on one side of the second tube section and in the cold air cavity 240 . The tube body 251 is filled with expansion fluid that can expand when heated.

[0033] Furthermore, the inclination directions of the tubes 251 on every two heat exchange plates 220 adjacently arranged in the first direction are opposite.

[0034] In a further embodiment, the multiple heat exchange tubes 250 on the same heat exchange plate 220 are divided into two groups, the number of heat exchange tubes 250 in each group is the same, the two groups of heat exchange tubes 250 are symmetrically arranged about the central axis of the heat exchange plate 220 in the second direction, and the inclination degrees of the multiple heat exchange tubes 250 in the same group are different.

[0035] By arranging the corrugated section 253 on the tube body 251, when in use, the expansion fluid inside the tube body 251 expands after being heated, so that the volume inside the tube body 251 increases, and then the corrugated section 253 stretches and lengthens. The stretching and lengthening of the corrugated section 253 will cause one side of the second tube section to extend in the cold air chamber 240, press against the side wall of the heat exchange plate 220, and cause the heat exchange plate 220 itself to deform, increase the volume of the cold air chamber 240, and allow more room temperature gas to enter the cold air chamber 240. The increase in air flow will enhance the gas flow during the heat exchange process, help the gas exchange during the heat exchange process, enhance the conduction and exchange of heat, and further improve the heat exchange efficiency. In addition, arranging the heat exchange tube 250 with different inclinations can adjust the timing of the extension of the second tube section of the heat exchange tube 250, control the degree of increase in the volume of the cold air chamber 240, and avoid a sudden increase in the volume of the cold air chamber 240.

[0036] Specifically, a sleeve 254 is disposed inside the tube body 251 , and the sleeve 254 is located in the through hole and is coaxial with the through hole.

[0037] By providing the sleeve 254, the tube body 251 is limited so that the tube body 251 can maintain a coaxial state when it is extended and against the inner wall of the heat exchange plate 220.

[0038] In this embodiment, both ends of the through hole are provided with a protective film 255. The protective film 255 is provided to prevent the condensed water after liquefaction from flowing directly through the through hole.

[0039] In combination with the above embodiments, the specific working process is as follows: During use, the flue gas is passed into the hot air chamber 230 from the hot end inlet 130 side, and the normal temperature gas is sent into the cold air chamber 240 from the cold end inlet 110 side. The flue gas entering the hot air chamber 230 will exchange heat with the normal temperature gas entering the cold air chamber 240 through the heat exchange plate 220, and after entering the hot air chamber 230, the flue gas will flow in the hot air chamber 230 and pass through the sponge layer 252 on the heat exchange tube 250. The water vapor in the flue gas will follow the sponge layer 252 to the cold air chamber 240, and liquefy into condensed water in the cold air chamber 240. In this process, latent heat is released, and part of the liquefied condensed water will be carried away by the air in the cold air chamber 240. In this process, the condensed water evaporates and takes away more heat, so that the waste heat of the flue gas is recovered. On the basis of heat exchange of the heat exchange plate 220, auxiliary heat exchange is carried out in combination with the heat exchange tube 250. The condensed water liquefied by the cold air chamber 240 can flow back to the hot air chamber 230 through the sponge layer 252, flow downward along the surface of the heat exchange plate 220 in the hot air chamber 230, and finally enter the water collecting tank and be led out from the water pipe 170 to prevent the condensed water from flowing back to the boiler flue and causing corrosion. The expansion liquid inside the tube body 251 will also expand after being heated, so that the volume inside the tube body 251 increases, and then the corrugated section 253 stretches and lengthens. The stretching and lengthening of the corrugated section 253 will cause one side of the second tube section to extend in the cold air chamber 240, supporting the side wall of the heat exchange plate 220, causing the heat exchange plate 220 itself to deform, increasing the volume of the cold air chamber 240, so that more normal temperature gas can be introduced into the cold air chamber 240. The increase in air flow will enhance the gas flow in the heat exchange process, help the gas exchange in the heat exchange process, enhance the conduction and exchange of heat, and further improve the heat exchange efficiency.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A boiler flue directly connected to flue gas waste heat recovery heat exchanger, characterized in that: The heat exchange device comprises a box body and a heat exchange device, wherein the heat exchange device is installed in the box body; the heat exchange device comprises a frame body and a plurality of heat exchange plates, wherein the plurality of heat exchange plates are sequentially arranged on the frame body along a first direction, wherein the first direction is a horizontal direction, and the plurality of heat exchange plates define a plurality of hot air chambers and a plurality of cold air chambers sequentially arranged along the first direction on the frame body, and the hot air chambers and the cold air chambers are alternately distributed in sequence in the first direction; the hot air chambers are connected in a second direction, wherein the second direction is a vertical direction, and smoke is passed through the hot air chambers, and the cold air chambers are connected in a third direction, wherein the third direction is horizontal and parallel to the first direction. In the vertical direction, room temperature gas flows in the cold air cavity; a plurality of heat exchange tubes are arranged on each heat exchange plate, and the plurality of heat exchange tubes are arranged in sequence along the second direction on the corresponding heat exchange plate, and the heat exchange tubes pass through the hot air cavity along the first direction and extend into the cold air cavity adjacent to the hot air cavity; the heat exchange tube includes a tube body and a sponge layer; the tube body is columnar, and a through hole is coaxially opened on the tube body, and the two ends along the axial direction of the tube body are respectively called the head end and the tail end, one end of the sponge layer is installed on the head end of the tube body, and the other end passes through the through hole and is wound around the tail end of the tube body.

2. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 1, characterized in that: A cold end inlet, a cold end outlet, a hot end inlet and a flue connection port are provided on the box body; the hot end inlet and the flue connection port are arranged face to face along the second direction on the box body, the hot end inlet is connected with the flue connection port through a hot air cavity, the cold end inlet and the cold end outlet are arranged face to face along the third direction on the box body, and the cold end inlet is connected with the cold end outlet through a cold air cavity.

3. A boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 2, characterized in that: The tube body is arranged obliquely, and the part of the tube body in the hot air cavity is called the first tube section, and the part of the tube body in the cold air cavity is called the second tube section; the two ends of the first tube section along the axial direction of the tube body are respectively called the first end and the second end, the first end is located on the side of the second end away from the second tube section in the axial direction of the tube body, the first end is located on the side of the second end close to the hot end inlet in the second direction, and the sponge layer located on one side of the first tube section is in contact with the heat exchange plate, and two water collecting plates are arranged on one side of the hot end inlet, both of which are located in the hot air cavity, and the two water collecting plates are respectively arranged on the heat exchange plate where the tube body is located and another heat exchange plate arranged adjacent to the heat exchange plate in the first direction.

4. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 3 is characterized by: A water collecting trough is provided on the water collecting plate, and the lower end of the water collecting plate is connected with a water pipe.

5. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 3, characterized in that: The interior of the tube body is hollow and has a corrugated section, which is located at one side of the second tube section and in the cold air cavity. The interior of the tube body is filled with expansion fluid, which can expand when heated.

6. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 3, characterized in that: The inclination directions of the tubes on every two heat exchange plates adjacently arranged in the first direction are opposite.

7. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 3, characterized in that: A sleeve is arranged inside the tube body, and the sleeve is located in the through hole and is coaxial with the through hole.

8. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 3, characterized in that: Both ends of the through hole are provided with protective films.

9. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 1, characterized in that: A heat-insulating layer is arranged between the heat exchange device and the box body, and heat-insulating cotton is arranged on the heat-insulating layer.

10. The boiler flue directly connected flue gas waste heat recovery heat exchanger according to claim 1, characterized in that: The heat exchange tube is installed on the heat exchange plate through the mounting plate.

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