A flue gas waste heat exchanger and heat exchange system

Abstract

The utility model discloses a flue gas waste heat heat exchanger and heat exchange system belong to flue gas waste heat recovery equipment technical field, including the casing, the both ends of casing set up tube sheet subassembly respectively, set up several heat exchange pipes between two tube sheet subassembly, set up the through -hole of intercommunication with heat exchange pipe on tube sheet subassembly, the side of two tube sheet subassembly opposite sets up the tube side end socket, set up the tube side inlet on one of tube side end socket, set up the tube side outlet on one of tube side end socket, set up flue gas inlet and flue gas outlet on the casing, the heat exchange pipe is silicon carbide pipe, the heat exchange pipe inserts corresponding through -hole and carries out sealing cooperation, and the end of heat exchange pipe close to tube sheet subassembly is coaxially fixed and sets up the flow resistance ring, the heat exchange pipe is silicon carbide pipe in the utility model discloses, and silicon carbide pipe can be completely resistant to the corrosion caused by sulfur oxide etc. in flue gas, the flow resistance ring plays a certain blocking effect to acidic condensate, and the probability of the sealing effect between heat exchange pipe and tube sheet subassembly being invalid due to the corrosion effect is reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of flue gas waste heat recovery equipment, specifically relating to a flue gas waste heat heat exchanger and heat exchange system. Background Technology

[0002] Flue gas waste heat exchangers are typically installed in the flue gas exhaust pipes of industrial boilers, hot blast stoves, kilns, or other combustion equipment. The high-temperature flue gas generated during combustion passes through the shell side of the flue gas waste heat exchanger and exchanges heat with the heat transfer medium passing through the tube side of the flue gas waste heat exchanger. The heat transfer medium absorbs the waste heat of the flue gas, and the heat transfer medium can be water or air.

[0003] However, in traditional flue gas waste heat exchangers, the heat exchange tubes are mostly made of metal. The flue gas in the exhaust pipes contains carbon monoxide, carbon dioxide, nitrogen oxides, sulfur oxides, water vapor, and suspended particulate matter. Sulfur oxides and water vapor in the flue gas easily condense on the heat exchange tube walls, corroding the tubes. Furthermore, when the condensed acidic liquid reaches the connection between the heat exchange tubes and the tube sheet, its corrosive effect can cause the seal between the tubes and the tube sheet to fail, leading to the mixing of flue gas and the heat transfer medium. This not only affects the heat exchange efficiency but also contaminates the heat transfer medium. Utility Model Content

[0004] To address the problem of easy corrosion of heat exchange tubes in existing flue gas waste heat exchangers, this utility model provides a flue gas waste heat exchanger.

[0005] A flue gas waste heat exchanger includes a shell, tube sheet assemblies are respectively provided at both ends of the shell, a plurality of heat exchange tubes are fixedly arranged between the two tube sheet assemblies, through holes connected to the heat exchange tubes are provided on the tube sheet assemblies, and tube end caps are provided on the opposite sides of the two tube sheet assemblies.

[0006] One of the tube end caps is provided with a tube inlet, and the other tube end cap is provided with a tube outlet.

[0007] The casing is provided with a flue gas inlet and a flue gas outlet;

[0008] The heat exchange tube is a silicon carbide tube;

[0009] After the heat exchange tube is inserted into the corresponding through hole, a sealing fit is formed, and a flow-blocking ring is coaxially fixed on the end of the heat exchange tube near the tube sheet assembly.

[0010] Preferably, a plurality of support plates are arranged axially inside the housing, and the support plates are provided with support holes for each heat exchange tube to pass through;

[0011] The support plate divides the inner cavity of the shell into multiple partitioned cavities, and adjacent partitioned cavities are interconnected.

[0012] Each compartment has a flue gas inlet at the top and a flue gas outlet at the bottom.

[0013] Preferably, the upper and lower parts of the support plate are adapted to and fixedly connected to the inner wall of the shell, and the front and rear sides of the support plate form a communication channel with the inner wall of the shell.

[0014] Preferably, an elastic sleeve for supporting the heat exchange tube is coaxially fixed inside the support hole.

[0015] Preferably, an annular boss is coaxially provided in the through hole, a threaded sleeve is threaded on the side of the through hole facing the corresponding side tube end cap, a sealing assembly is fitted on the heat exchange tube between the annular boss and the threaded sleeve, and a gasket is fitted on the heat exchange tube between the threaded sleeve and the sealing assembly.

[0016] Preferably, the sealing assembly consists of a plurality of sealing rings arranged axially.

[0017] Preferably, the tube inlet and tube outlet are located on different tube end caps.

[0018] Preferably, the tube inlet and tube outlet are located on the same tube end cap, and the tube end cap is provided with a partition plate inside to divide the inner cavity of the tube end cap into two end cap cavities, which are respectively connected to the tube inlet and the tube outlet.

[0019] This utility model also provides a flue gas waste heat exchange system.

[0020] A flue gas waste heat exchange system includes an outer casing, and a plurality of flue gas waste heat exchangers are arranged horizontally inside the outer casing.

[0021] The outer casing is equipped with a smoke baffle, which divides the inner cavity of the outer casing into an upper smoke inlet chamber and a lower smoke outlet chamber.

[0022] The flue gas inlets of all flue gas waste heat exchangers are located in the inlet chamber, and the flue gas outlets of all flue gas waste heat exchangers are located in the outlet chamber.

[0023] This utility model also provides a flue gas waste heat exchange system.

[0024] A flue gas waste heat exchange system includes an outer casing, with a plurality of outer casing partitions arranged vertically inside the outer casing, the outer casing partitions dividing the inner cavity of the outer casing into a plurality of outer casing partition cavities, and a plurality of flue gas waste heat exchangers arranged horizontally inside each outer casing partition cavity.

[0025] Each outer casing compartment is equipped with a smoke baffle, which divides the outer casing compartment into an upper smoke inlet chamber and a lower smoke outlet chamber.

[0026] In each outer casing partition, the flue gas inlets of all flue gas waste heat exchangers are located in the inlet chamber, and the flue gas outlets of all flue gas waste heat exchangers are located in the outlet chamber.

[0027] The outer casing partition has a connecting hole.

[0028] The beneficial effects of this utility model are:

[0029] (1) The heat exchange tube in this utility model is a silicon carbide tube. The silicon carbide tube can fully withstand the corrosion caused by sulfur oxides in the flue gas, and has a longer service life, which solves the defect of existing metal heat exchange tubes being easily corroded.

[0030] (2) In this utility model, the flow-blocking ring plays a certain role in blocking the acidic condensate, thereby reducing the probability of the acidic condensate flowing into the through hole between the heat exchange tube and the tube sheet assembly, and reducing the probability of the sealing effect between the heat exchange tube and the tube sheet assembly failing due to corrosion.

[0031] (3) By setting up a support plate, this utility model can support the heat exchange tube on the one hand, and isolate each flue gas inlet and outlet on the other hand, reduce gas interference caused by the flow obstruction of the heat exchange tube after the flue gas enters the shell side, reduce pressure drop, and facilitate the rapid heat exchange and outflow of flue gas.

[0032] (4) The flue gas inlet and flue gas outlet in this utility model correspond to each other to achieve cross-flow heat exchange. Compared with the counter-flow heat exchange in the existing heat exchanger where gas enters from one end of the shell side and exits from the other end, it can accommodate a larger flue gas flow and a smaller pressure drop, thereby reducing the probability of acid liquid condensation and reducing the risk of corrosion.

[0033] (5) The flue gas waste heat exchange system in this utility model improves the adaptability of waste heat recovery of flue gas of different scales, and the baffle plate enables the flue gas to pass through the heat exchanger only, thereby improving the heat exchange capacity. Attached Figure Description

[0034] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0035] Figure 1 This is a schematic diagram of the flue gas waste heat exchanger in Embodiment 1 of this utility model;

[0036] Figure 2 This is a schematic diagram of the fit between the heat exchange tube and the support plate in this utility model;

[0037] Figure 3 This is a schematic diagram of the elastic sleeve on the support plate in this utility model;

[0038] Figure 4 This is a schematic diagram of the fit between the heat exchange tube and the tube sheet assembly in this utility model;

[0039] Figure 5 This is a schematic diagram of the structure of the flue gas waste heat exchanger in Embodiment 2 of this utility model;

[0040] Figure 6 This is a schematic diagram of the flue gas waste heat exchange system in Embodiment 3 of this utility model;

[0041] Figure 7 This is a schematic diagram of the flue gas waste heat exchange system in Embodiment 4 of this utility model;

[0042] in:

[0043] 1. Shell; 11. Flue gas inlet; 12. Flue gas outlet; 2. Tube sheet assembly; 21. Through hole; 22. Annular boss; 3. Heat exchange tube; 4. Tube end cap; 41. Tube inlet; 42. Tube outlet; 43. Partition plate; 5. Flow baffle ring; 6. Support plate; 61. Elastic sleeve; 7. Screw sleeve; 8. Gasket; 9. Sealing ring; 10. Outer casing; 101. Smoke baffle; 102. Smoke inlet chamber; 103. Smoke outlet chamber; 104. Outer casing partition plate. Detailed Implementation

[0044] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Example 1:

[0046] like Figure 1 As shown, a flue gas waste heat exchanger includes a shell 1, tube sheet assemblies 2 are respectively provided at both ends of the shell 1, a plurality of heat exchange tubes 3 are fixedly arranged between the two tube sheet assemblies 2, through holes 21 connected to the heat exchange tubes 3 are provided on the tube sheet assembly 2, and tube end caps 4 are provided on the opposite side of the two tube sheet assemblies 2.

[0047] One of the tube end caps 4 is provided with a tube inlet 41, and another of the tube end caps 4 is provided with a tube outlet 42;

[0048] The housing 1 is provided with a flue gas inlet 11 and a flue gas outlet 12;

[0049] The heat exchange tube 3 is a silicon carbide tube. Silicon carbide tubes can fully withstand corrosion caused by sulfur oxides in flue gas and have a longer service life. The tube sheet can be made of metal materials such as stainless steel and carbon steel to meet the requirements.

[0050] After the heat exchange tube 3 is inserted into the corresponding through hole 21, a sealing fit is formed. A flow-blocking ring 5 is coaxially fixed on the end of the heat exchange tube 3 near the tube sheet assembly 2. Multiple flow-blocking rings 5 ​​can be set on the end of the heat exchange tube 3 near the tube sheet assembly 2. The flow-blocking ring 5 plays a certain role in blocking the acidic condensate, thereby reducing the probability of the acidic condensate flowing into the through hole 21 between the heat exchange tube 3 and the tube sheet assembly 2, and reducing the probability of the sealing effect between the heat exchange tube 3 and the tube sheet assembly 2 failing due to corrosion.

[0051] Preferred, such as Figure 2 As shown, a plurality of support plates 6 are arranged axially inside the housing 1, and the support plates 6 are provided with support holes for each heat exchange tube 3 to pass through.

[0052] The support plate 6 divides the inner cavity of the shell 1 into multiple partitioned cavities, and adjacent partitioned cavities are interconnected.

[0053] Each partition chamber is provided with a flue gas inlet 11 at the top and a flue gas outlet 12 at the bottom. By setting multiple flue gas inlets 11 and outlets 12, the gas flow rate is increased and the pressure drop is reduced.

[0054] Preferably, the upper and lower parts of the support plate 6 are adapted to and fixedly connected to the inner wall surface of the shell 1, and the front and rear sides of the support plate 6 form a connecting channel with the inner wall of the shell 1, so that adjacent partition cavities can communicate with each other.

[0055] Preferred, such as Figure 3 As shown, an elastic sleeve 61 for supporting the heat exchange tube 3 is coaxially fixed inside the support hole. The heat exchange tube 3 is in direct contact with the elastic sleeve 61, which buffers the vibration of the heat exchange tube 3. Moreover, the heat exchange tube 3 will not directly contact the metal support plate 6 when vibrating, which can effectively reduce the risk of the silicon carbide tube breaking due to vibration and enhance the stability of the silicon carbide tube operation.

[0056] Preferred, such as Figure 4 As shown, an annular boss 22 is coaxially arranged inside the through hole 21. A threaded sleeve 7 is threaded onto the side of the through hole 21 facing the corresponding side tube end cap 4. A sealing assembly is fitted on the heat exchange tube 3 between the annular boss 22 and the threaded sleeve 7. A gasket 8 is fitted on the heat exchange tube 3 between the threaded sleeve 7 and the sealing assembly.

[0057] Preferably, the sealing assembly consists of a plurality of sealing rings 9 arranged axially.

[0058] During installation, the heat exchange tube 3 is inserted into the through hole 21, and then each sealing ring 9 is fitted onto the heat exchange tube 3. The threaded sleeve 7 is then installed and tightened, pressing the sealing rings 9 against the annular boss 22 via the gasket 8, thus achieving a sealed connection between the heat exchange tube 3 and the tube sheet assembly 2. The gasket 8 balances the clamping force, resulting in more uniform deformation of the sealing rings 9 and enhancing the sealing effect. The sealed connection between the heat exchange tube 3 and the tube sheet assembly 2 in this application can withstand 1.5 MPa and 200℃ hot water without leakage. A gap is left between the stepped end face of the inner hole of the threaded sleeve 7 and the end face of the heat exchange tube 3 to allow for movement during thermal expansion and contraction and vibration of the heat exchange tube 3.

[0059] Preferably, the tube inlet 41 and the tube outlet 42 are located on different tube end caps 4.

[0060] In Example 1, the tube-side medium flows in from the tube-side inlet 41 on one side of the tube-side end cap 4, then passes through the heat exchange tube 3, and flows out from the tube-side outlet 42 on the other side of the tube-side end cap 4.

[0061] Example 2:

[0062] Unlike in Example 1, as Figure 5 As shown, the tube inlet 41 and tube outlet 42 are located on the same tube head 4. The tube head 4 has a partition plate 43 inside, which divides the inner cavity of the tube head 4 into two head cavities. The two head cavities are respectively connected to the tube inlet 41 and the tube outlet 42. The first head cavity is connected to the tube inlet 41, and the second head cavity is connected to the tube outlet 42.

[0063] In Example 2, the tube-side medium flows in from the tube-side inlet 41 on the first end cap cavity, then enters the tube-side end cap 4 on the other side through the heat exchange tube 3 connected to the first end cap cavity, then enters the second end cap cavity through the heat exchange tube 3 connected to the second end cap cavity, and finally flows out from the tube-side outlet 42.

[0064] Example 3:

[0065] like Figure 6 As shown, a flue gas waste heat exchange system includes an outer casing 10, and a plurality of flue gas waste heat exchangers as described in Embodiment 1 or Embodiment 2 are arranged horizontally inside the outer casing 10.

[0066] The outer casing 10 is provided with a smoke baffle 101, which divides the inner cavity of the outer casing 10 into an upper smoke inlet chamber 102 and a lower smoke outlet chamber 103.

[0067] The flue gas inlet 11 of all flue gas waste heat exchangers is located in the flue gas inlet chamber 102, and the flue gas outlet 12 of all flue gas waste heat exchangers is located in the flue gas outlet chamber 103.

[0068] In Example 3, the upper opening of the outer casing 10 serves as the main flue gas inlet. The flue gas entering through the main flue gas inlet enters the flue gas inlet chamber 102, and then enters the shell side of the flue gas waste heat exchanger through each flue gas inlet 11. After exchanging heat with the heat transfer medium in the heat exchange tube 3, it enters the flue gas outlet chamber 103 through each flue gas outlet 12, and finally exits through the main flue gas outlet at the lower end of the outer casing 10.

[0069] Example 4:

[0070] like Figure 7 As shown, a flue gas waste heat exchange system includes an outer casing 10. Several outer casing partitions 104 are arranged vertically inside the outer casing 10. The outer casing partitions 104 divide the inner cavity of the outer casing 10 into several outer casing partition cavities. Several flue gas waste heat exchangers as described in Embodiment 1 or Embodiment 2 are arranged horizontally inside each outer casing partition cavity.

[0071] Each outer box partition cavity is equipped with a smoke baffle 101, which divides the outer box partition cavity into an upper smoke inlet cavity 102 and a lower smoke outlet cavity 103.

[0072] In each outer casing partition cavity, the flue gas inlet 11 of all flue gas waste heat exchangers is located in the flue gas inlet cavity 102, and the flue gas outlet 12 of all flue gas waste heat exchangers is located in the flue gas outlet cavity 103.

[0073] The outer casing partition 104 is provided with a connecting hole.

[0074] In Example 4, the upper end of the outer casing 10 is open as the main flue gas inlet. The flue gas entering through the main flue gas inlet enters the uppermost flue gas inlet chamber 102, and then enters the shell side of the uppermost flue gas waste heat exchanger through each flue gas inlet 11. After exchanging heat with the heat transfer medium in the heat exchange tube 3, it enters the corresponding flue gas outlet chamber 103 through each flue gas outlet 12, and then enters the next flue gas inlet chamber 102 through the corresponding connecting hole. This process continues until, after multiple heat exchanges, the flue gas is finally discharged from the flue gas outlet 12 of the lowermost flue gas waste heat exchanger to the lowermost flue gas outlet chamber 103, and finally discharged through the main flue gas outlet at the lower end of the outer casing 10.

[0075] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, they are not intended to limit the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the protection scope of the present utility model.

Claims

1. A flue gas waste heat exchanger, characterized in that, Includes a shell (1), with tube sheet assemblies (2) respectively provided at both ends of the shell (1), and a plurality of heat exchange tubes (3) fixedly arranged between the two tube sheet assemblies (2). The tube sheet assembly (2) is provided with through holes (21) that communicate with the heat exchange tubes (3), and tube end caps (4) are provided on the opposite side of the two tube sheet assemblies (2). One of the tube end caps (4) is provided with a tube inlet (41), and the other of the tube end caps (4) is provided with a tube outlet (42); The housing (1) is provided with a flue gas inlet (11) and a flue gas outlet (12); The heat exchange tube (3) is a silicon carbide tube; After the heat exchange tube (3) is inserted into the corresponding through hole (21), a sealing fit is formed. A flow-blocking ring (5) is coaxially fixed on the end of the heat exchange tube (3) near the tube sheet assembly (2).

2. The flue gas waste heat exchanger as described in claim 1, characterized in that, The housing (1) is provided with several support plates (6) arranged along the axial direction, and the support plates (6) are provided with support holes for each heat exchange tube (3) to pass through; The support plate (6) divides the inner cavity of the shell (1) into multiple partitioned cavities, and adjacent partitioned cavities are interconnected. Each partition chamber has a flue gas inlet (11) at the top and a flue gas outlet (12) at the bottom.

3. The flue gas waste heat exchanger as described in claim 2, characterized in that, The upper and lower parts of the support plate (6) are adapted to and fixedly connected to the inner wall of the shell (1), and the front and rear sides of the support plate (6) form a communication channel with the inner wall of the shell (1).

4. The flue gas waste heat exchanger as described in claim 2, characterized in that, An elastic sleeve (61) for supporting the heat exchange tube (3) is coaxially fixed inside the support hole.

5. The flue gas waste heat exchanger as described in claim 1, characterized in that, An annular boss (22) is coaxially arranged inside the through hole (21). A threaded sleeve (7) is threaded on the side of the through hole (21) facing the corresponding side tube end cap (4). A sealing assembly is fitted on the heat exchange tube (3) between the annular boss (22) and the threaded sleeve (7). A gasket (8) is fitted on the heat exchange tube (3) between the threaded sleeve (7) and the sealing assembly.

6. The flue gas waste heat exchanger as described in claim 5, characterized in that, The sealing assembly consists of several sealing rings (9) arranged axially.

7. The flue gas waste heat exchanger as described in claim 1, characterized in that, The tube inlet (41) and tube outlet (42) are located on different tube heads (4).

8. The flue gas waste heat exchanger as described in claim 1, characterized in that, The tube inlet (41) and tube outlet (42) are located on the same tube head (4). The tube head (4) is provided with a partition plate (43) to divide the inner cavity of the tube head (4) into two head cavities. The two head cavities are respectively connected to the tube inlet (41) and the tube outlet (42).

9. A flue gas waste heat exchange system, characterized in that, Includes an outer casing (10), and the interior of the outer casing (10) is provided with a plurality of flue gas waste heat exchangers as described in any one of claims 1 to 8; The outer casing (10) is provided with a smoke baffle (101), which divides the inner cavity of the outer casing (10) into an upper smoke inlet chamber (102) and a lower smoke outlet chamber (103); The flue gas inlet (11) of all flue gas waste heat exchangers is located in the flue gas inlet chamber (102), and the flue gas outlet (12) of all flue gas waste heat exchangers is located in the flue gas outlet chamber (103).

10. A flue gas waste heat exchange system, characterized in that, Includes an outer casing (10), wherein a plurality of outer casing partitions (104) are arranged in the vertical direction inside the outer casing (10), the outer casing partitions (104) divide the inner cavity of the outer casing (10) into a plurality of outer casing partition cavities, and each outer casing partition cavity is provided with a plurality of flue gas waste heat exchangers as described in any one of claims 1 to 8 in the horizontal direction. Each outer box partition is provided with a smoke baffle (101), which divides the outer box partition into an upper smoke inlet chamber (102) and a lower smoke outlet chamber (103); In each outer casing partition, the flue gas inlet (11) of all flue gas waste heat exchangers is located in the flue gas inlet chamber (102), and the flue gas outlet (12) of all flue gas waste heat exchangers is located in the flue gas outlet chamber (103). The outer casing partition (104) is provided with a connecting hole.

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