Parallel plate type heat exchanger set and heat exchange method

Abstract

The invention relates to the technical field of heat exchangers, in particular to a parallel plate heat exchanger set which comprises a hot side water inlet main pipe, a hot side water return main pipe, a cold side water inlet main pipe and a cold side water return main pipe. A plurality of cold fluid units are arranged on the surfaces of the cold side water inlet main pipe and the cold side water return main pipe, a plurality of heat exchanger bodies are arranged between the hot side water inlet main pipe and the hot side water return main pipe and between the cold side water inlet main pipe and the cold side water return main pipe, and a first connecting device is arranged between the second hot side water inlet branch pipe and the hot side water inlet main pipe. The third electromagnetic valves connected with the other one or more heat exchanger bodies are opened, and the heat exchanger bodies connected in parallel are added, so that the flow is increased, and the requirements of the hot fluid equipment body and the cold fluid equipment body are met; the other heat exchanger body is started to replace the heat exchanger body needing to be overhauled or replaced, and heat exchange work of the heat exchanger set is not affected.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and in particular to a parallel plate heat exchanger group and a heat exchange method. Background Art

[0002] A heat exchanger, also known as a heat exchanger, is a device that transfers part of the heat of a hot fluid to a cold fluid. Heat exchangers play an important role in chemical, petroleum, power, food, and many other industrial production processes. In chemical production, heat exchangers can be used as heaters, coolers, condensers, evaporators, and reboilers, and are widely used. However, plate heat exchangers are designed with different specifications for hot and cold fluid equipment, and heat exchangers cannot be stacked based on the flow rates of hot and cold fluid equipment. If a hot or cold fluid equipment with a high flow rate is replaced, the heat exchanger must be replaced, which is very inconvenient. Furthermore, if one heat exchanger is damaged and needs to be repaired or replaced, there is no other heat exchanger to quickly replace it, and the heat exchanger cannot be switched after long periods of operation. Summary of the Invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a parallel plate heat exchanger group and a heat exchange method.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A parallel plate heat exchanger group is designed, including a hot side water inlet main pipe, a hot side return water main pipe, a cold side water inlet main pipe and a cold side return water main pipe. The surfaces of the hot side water inlet main pipe and the hot side return water main pipe are provided with multiple hot fluid units, and the surfaces of the cold side water inlet main pipe and the cold side return water main pipe are provided with multiple cold fluid units. Multiple heat exchanger bodies are provided between the hot side water inlet main pipe, the hot side return water main pipe and the cold side water inlet main pipe and the cold side return water main pipe. A second hot side water inlet branch pipe and a second hot side return branch pipe are provided on one side surface of the heat exchanger body. A second cold side water inlet branch and a second cold side return branch are provided on the other side surface of the device body. A first connecting device is provided between the second hot side water inlet branch and the hot side water inlet main pipe, a second connecting device is provided between the second hot side return branch and the hot side return main pipe, a third connecting device is provided between the second cold side water inlet branch and the cold side water inlet main pipe, and a fourth connecting device is provided between the second cold side return branch and the cold side return main pipe. The first connecting device, the second connecting device, the third connecting device and the fourth connecting device have the same structure.

[0005] Preferably, the thermal fluid unit includes a first hot side water inlet branch, a first hot side return branch and a thermal fluid equipment body. The thermal fluid equipment body is connected to the hot side water inlet main pipe through the first hot side water inlet branch, and the thermal fluid equipment body is connected to the hot side return main pipe through the first hot side return branch. The surfaces of the first hot side water inlet branch and the first hot side return branch are both provided with a first stop valve and a first solenoid valve.

[0006] Preferably, the cold fluid unit includes a first cold side water inlet branch, a first cold side return branch and a cold fluid equipment body. The cold fluid equipment body is connected to the cold side water inlet main pipe through the first cold side water inlet branch, and the cold fluid equipment body is connected to the cold side return main pipe through the first cold side return branch. The surfaces of the first cold side water inlet branch and the first cold side return branch are both provided with a second shut-off valve and a second solenoid valve.

[0007] Preferably, the first connecting device includes a first connecting pipe, which is connected to the hot side water inlet main pipe, and a third stop valve and a third solenoid valve are provided on the surface of the first connecting pipe. A limit block is provided in a ring shape at one end of the second hot side water inlet branch pipe close to the first connecting pipe, and a covering block is rotatably connected to the surface of the second hot side water inlet branch pipe, and the inner wall of one side of the covering block is tightly pressed against the limiting block. The inner wall of the covering block is threadedly connected to one end of the first connecting pipe, and raw tape is wrapped between the inner wall of the covering block and the surface of the first connecting pipe.

[0008] Preferably, a first sealing gasket is provided between the second hot-side water inlet branch pipe and the first connecting pipe.

[0009] Preferably, an annular protrusion is provided on one side surface of the first sealing gasket close to the first connecting pipe, and an annular groove is opened on one side surface of the first connecting pipe close to the first sealing gasket, and the annular protrusion matches the annular groove and is clamped with each other.

[0010] Preferably, a positioning groove is provided in an annular manner on the inner wall of the first connecting pipe on one side close to the second hot side water inlet branch pipe, and a positioning block is integrally formed in an annular manner on the surface of the first sealing gasket on one side close to the positioning groove, and the positioning block matches the positioning groove.

[0011] Preferably, a second sealing gasket is provided between the limiting block and the covering block.

[0012] Preferably, the surfaces of the hot-side water inlet main pipe, the hot-side water return main pipe, the cold-side water inlet main pipe and the cold-side water return main pipe are all connected with a plurality of second connecting pipes, and the inner walls of the plurality of second connecting pipes are all threadedly connected with plugs.

[0013] The present invention also provides a heat exchange method for a parallel plate heat exchanger group, comprising the following steps: S1: First, wrap the raw tape around the first connecting pipe, then thread the cover block to the corresponding first connecting pipe, and install the first connecting device, the second connecting device, the third connecting device, and the fourth connecting device in sequence; S2: After multiple heat exchanger bodies are installed, the first solenoid valve of the unnecessary hot fluid unit is closed, and the second solenoid valve of the unnecessary cold fluid unit is closed. The first solenoid valve of the single hot fluid device body to be used is opened, and the second solenoid valve of the single cold fluid device body to be used is opened. The hot fluid device body to be used and the cold fluid device body to be used exchange heat through the heat exchanger body; S3: The hot fluid in the hot fluid device body enters the hot side water inlet main pipe through the first hot side water inlet branch pipe, and then flows back to the hot fluid device body through the first hot side water return branch pipe. The cold fluid in the cold fluid device body enters the cold side water inlet main pipe through the first cold side water inlet branch pipe, and then exchanges heat through the heat exchanger body. After heat exchange, the cold fluid flows back to the cold fluid device body through the second cold side water return branch pipe; S4: If the flow rate of the hot fluid device body and the cold fluid device body is large, the third solenoid valve connected to one or more heat exchanger bodies is opened to increase the heat exchanger bodies connected in parallel to increase the flow rate to meet the needs of the hot fluid device body and the cold fluid device body; S5: If the heat exchanger body needs to be repaired or replaced, the third solenoid valve connected to the heat exchanger body that needs to be repaired or replaced is closed; S6: Unscrewing the covering block from the first connecting pipe and then removing the heat exchanger body that needs to be repaired or replaced, at this time, opening another heat exchanger body to replace the heat exchanger body that needs to be repaired or replaced.

[0014] S7: The program control is performed through the control end, and the third solenoid valves on different heat exchanger bodies are switched on and off to achieve the effect of switching heat exchange between different heat exchanger bodies.

[0015] The present invention proposes a parallel plate heat exchanger group and heat exchange method, which have the following beneficial effects: the plate heat exchanger does not need to design heat exchanger bodies of different specifications according to the hot fluid device body and the cold fluid device body. If the flow rate of the hot fluid device body and the cold fluid device body is large, by opening the third solenoid valve connected to another one or more heat exchanger bodies, the parallel heat exchanger bodies are added to increase the flow rate to meet the needs of the hot fluid device body and the cold fluid device body, without having to replace the heat exchanger body, which is very convenient; At the same time, if the heat exchanger body is damaged and needs to be repaired or replaced, the third solenoid valve connected to the heat exchanger body that needs to be repaired or replaced is closed, and then the covering block is unscrewed from the first connecting pipe, and then the heat exchanger body that needs to be repaired or replaced is removed. At this time, another heat exchanger body is opened to replace the heat exchanger body that needs to be repaired or replaced, which does not affect the heat exchange work of the heat exchanger group. The program control is performed through the control end, and the opening and closing of the third solenoid valves on different heat exchanger bodies are switched to achieve the effect of switching heat exchange of different heat exchanger bodies, thereby avoiding long-term operation of the heat exchanger body and shortening the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention.

[0017] Figure 2 It is an enlarged view of position A of the present invention.

[0018] Figure 3 It is an enlarged view of position B of the present invention.

[0019] Figure 4 It is an enlarged view of position C of the present invention.

[0020] Figure 5 It is an enlarged view of position D of the present invention.

[0021] Figure 6 This is a cross-sectional view of the first connecting device structure of the present invention.

[0022] Figure 7 It is an enlarged view of position E of the present invention.

[0023] In the figure: hot side water inlet main pipe 1, hot side return water main pipe 2, cold side water inlet main pipe 3, cold side return water main pipe 4, first hot side water inlet branch pipe 5, first hot side return water branch pipe 6, hot fluid equipment body 7, first cold side water inlet branch pipe 8, first cold side return water branch pipe 9, cold fluid equipment body 10, heat exchanger body 11, first stop valve 12, first solenoid valve 13, second hot side water inlet branch pipe 14, second hot side return water branch pipe 15, second stop valve 16, second solenoid valve 17, second cold side water inlet branch pipe 18, second cold side return water branch pipe 19, first connecting pipe 20, third stop valve 21, third solenoid valve 22, limit block 23, covering block 24, raw tape 25, first sealing gasket 26, annular protrusion 27, annular groove 28, positioning groove 29, positioning block 30, second sealing gasket 31, second connecting pipe 32, plug 33. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] Reference Figure 1-7 A parallel plate heat exchanger group includes a hot side water inlet main pipe 1, a hot side return water main pipe 2, a cold side water inlet main pipe 3 and a cold side return water main pipe 4. The surfaces of the hot side water inlet main pipe 1 and the hot side return water main pipe 2 are provided with multiple hot fluid units, and the surfaces of the cold side water inlet main pipe 3 and the cold side return water main pipe 4 are provided with multiple cold fluid units. Multiple heat exchanger bodies 11 are provided between the hot side water inlet main pipe 1, the hot side return water main pipe 2 and the cold side water inlet main pipe 3 and the cold side return water main pipe 4. One side surface of the heat exchanger body 11 is provided with a second hot side water inlet branch pipe 14 and a second hot side water return branch pipe 15. A second cold side water inlet branch 18 and a second cold side return branch 19 are provided on the other side surface of the device body 11, a first connecting device is provided between the second hot side water inlet branch 14 and the hot side water inlet main pipe 1, a second connecting device is provided between the second hot side return branch 15 and the hot side return main pipe 2, a third connecting device is provided between the second cold side water inlet branch 18 and the cold side water inlet main pipe 3, and a fourth connecting device is provided between the second cold side return branch 19 and the cold side return main pipe 4. The first connecting device, the second connecting device, the third connecting device and the fourth connecting device have the same structure.

[0026] The thermal fluid unit includes a first hot-side water inlet branch 5, a first hot-side water return branch 6, and a thermal fluid device body 7. The thermal fluid device body 7 is connected to the hot-side water inlet main pipe 1 via the first hot-side water inlet branch 5, and is connected to the hot-side water return main pipe 2 via the first hot-side water return branch 6. A first stop valve 12 and a first solenoid valve 13 are provided on the surfaces of the first hot-side water inlet branch 5 and the first hot-side water return branch 6. If the first solenoid valve 13 connected to the thermal fluid device body 7 is closed, the thermal fluid device body 7 can be replaced. If the first solenoid valve 13 fails, the first stop valve 12 can be closed.

[0027] The cold fluid unit includes a first cold-side water inlet branch 8, a first cold-side water return branch 9, and a cold fluid device body 10. The cold fluid device body 10 is connected to the cold-side water inlet main pipe 3 via the first cold-side water inlet branch 8, and is connected to the cold-side water return main pipe 4 via the first cold-side water return branch 9. A second shut-off valve 16 and a second solenoid valve 17 are provided on the surfaces of the first cold-side water inlet branch 8 and the first cold-side water return branch 9. If the second solenoid valve 17 connected to the cold fluid device body 10 is closed, the cold fluid device body 10 can be replaced. If the second solenoid valve 17 fails, the second shut-off valve 16 can be closed.

[0028] The first connecting device includes a first connecting pipe 20, which is connected to the hot side water inlet main pipe 1. A third stop valve 21 and a third solenoid valve 22 are provided on the surface of the first connecting pipe 20. A limit block 23 is provided in a ring at one end of the second hot side water inlet branch pipe 14 close to the first connecting pipe 20. A covering block 24 is rotatably connected to the surface of the second hot side water inlet branch pipe 14. The inner wall of one side of the covering block 24 is tightly pressed against the limit block 23. The inner wall of the covering block 24 is threadedly connected to one end of the first connecting pipe 20. A raw tape 25 is wrapped between the inner wall of the covering block 24 and the surface of the first connecting pipe 20. By wrapping the raw tape 25, the first connecting pipe 20 and the covering block 24 are more tightly connected.

[0029] A first sealing gasket 26 is installed between the second hot-side water inlet branch pipe 14 and the first connecting pipe 20. The first sealing gasket 26 provides a seal. An annular protrusion 27 is provided on the side of the first sealing gasket 26 that is closest to the first connecting pipe 20. An annular groove 28 is formed on the side of the first connecting pipe 20 that is closest to the first sealing gasket 26. The annular protrusion 27 and the annular groove 28 mate and engage with each other. The annular protrusion 27 extends into the annular groove 28, further tightening the connection between the first connecting pipe 20 and the first sealing gasket 26.

[0030] A positioning groove 29 is formed in an annular manner on the inner wall of the first connecting pipe 20 on the side closest to the second hot-side water inlet branch pipe 14. A positioning block 30 is integrally formed in an annular manner on the surface of the first sealing gasket 26 on the side closest to the positioning groove 29. The positioning block 30 mates with the positioning groove 29. The positioning block 30 prevents the first sealing gasket 26 from warping and leaking liquid. At the same time, the positioning groove 29 accommodates the positioning block 30, preventing it from affecting the flow of fluid.

[0031] A second sealing gasket 31 is provided between the limiting block 23 and the covering block 24. The second sealing gasket 31 serves to make the limiting block 23 and the covering block 24 more tightly connected.

[0032] The hot-side inlet main pipe 1, the hot-side return main pipe 2, the cold-side inlet main pipe 3, and the cold-side return main pipe 4 are all connected by multiple second connecting pipes 32. The inner walls of the multiple second connecting pipes 32 are all threaded with plugs 33. By removing the plugs 33, a new heat exchanger body 11 can be connected.

[0033] A heat exchange method for a parallel plate heat exchanger group comprises the following steps: S1: First, wrap the raw tape 25 around the first connecting pipe 20, then thread the cover block 24 to the corresponding first connecting pipe 20, and install the first connecting device, the second connecting device, the third connecting device, and the fourth connecting device in sequence; S2: After the installation of multiple heat exchanger bodies 11 is completed, the first solenoid valve 13 of the unnecessary hot fluid unit is closed, and the second solenoid valve 17 of the unnecessary cold fluid unit is closed. The first solenoid valve 13 of the single hot fluid device body 7 to be used is opened, and the second solenoid valve 17 of the single cold fluid device body 10 to be used is opened. The hot fluid device body 7 to be used and the cold fluid device body 10 to be used exchange heat through the heat exchanger body 11; S3: The hot fluid in the hot fluid device body 7 enters the hot side water inlet main pipe 1 through the first hot side water inlet branch pipe 5, and then flows back to the hot fluid device body 7 through the first hot side water return branch pipe 6. The cold fluid in the cold fluid device body 10 enters the cold side water inlet main pipe 3 through the first cold side water inlet branch pipe 8, and then exchanges heat through the heat exchanger body 11. After heat exchange, the cold fluid flows back to the cold fluid device body 10 through the second cold side water return branch pipe 19; S4: If the flow rate of the hot fluid device body 7 and the cold fluid device body 10 is large, the third solenoid valve 22 connected to another one or more heat exchanger bodies 11 is opened to increase the heat exchanger body 11 in parallel to increase the flow rate to meet the needs of the hot fluid device body 7 and the cold fluid device body 10. There is no need to replace the heat exchanger body 11, which is very convenient. S5: If the heat exchanger body 11 needs to be repaired or replaced, the third solenoid valve 22 connected to the heat exchanger body 11 that needs to be repaired or replaced is closed; S6: Unscrew the covering block 24 from the first connecting pipe 20, and then remove the heat exchanger body 11 that needs to be repaired or replaced. At this time, open another heat exchanger body 11 to replace the heat exchanger body 11 that needs to be repaired or replaced, without affecting the heat exchange work of the heat exchanger group.

[0034] S7: The control end is used for program control to switch the opening and closing of the third solenoid valve 22 on different heat exchanger bodies 11 to achieve the effect of switching heat exchange between different heat exchanger bodies 11, thereby preventing the heat exchanger bodies 11 from working for a long time and shortening their service life.

[0035] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A parallel plate heat exchanger group, comprising a hot side water inlet main pipe (1), a hot side water return main pipe (2), a cold side water inlet main pipe (3) and a cold side water return main pipe (4), characterized in that: The surfaces of the hot side water inlet main pipe (1) and the hot side water return main pipe (2) are provided with a plurality of hot fluid units, and the surfaces of the cold side water inlet main pipe (3) and the cold side water return main pipe (4) are provided with a plurality of cold fluid units. A plurality of heat exchanger bodies (11) are provided between the hot side water inlet main pipe (1), the hot side water return main pipe (2), the cold side water inlet main pipe (3), and the cold side water return main pipe (4). A second hot side water inlet branch pipe (14) and a second hot side water return branch pipe (15) are provided on one side surface of the heat exchanger body (11), and a second cold side water inlet branch pipe (14) and a second hot side water return branch pipe (15) are provided on the other side surface of the heat exchanger body (11). A first connecting device is provided between the second hot side water inlet branch pipe (14) and the hot side water inlet main pipe (1), a second connecting device is provided between the second hot side water return branch pipe (15) and the hot side water return main pipe (2), a third connecting device is provided between the second cold side water inlet branch pipe (18) and the cold side water inlet main pipe (3), a fourth connecting device is provided between the second cold side water return branch pipe (19) and the cold side water return main pipe (4), and the first connecting device, the second connecting device, the third connecting device and the fourth connecting device have the same structure.

2. The parallel plate heat exchanger group according to claim 1, characterized in that: The thermal fluid unit comprises a first hot side water inlet branch pipe (5), a first hot side water return branch pipe (6) and a thermal fluid device body (7); the thermal fluid device body (7) is connected to the hot side water inlet main pipe (1) via the first hot side water inlet branch pipe (5); the thermal fluid device body (7) is connected to the hot side water return main pipe (2) via the first hot side water return branch pipe (6); and a first stop valve (12) and a first solenoid valve (13) are provided on the surfaces of the first hot side water inlet branch pipe (5) and the first hot side water return branch pipe (6).

3. The parallel plate heat exchanger group according to claim 1, characterized in that: The cold fluid unit comprises a first cold side water inlet branch pipe (8), a first cold side water return branch pipe (9) and a cold fluid equipment body (10); the cold fluid equipment body (10) is connected to the cold side water inlet main pipe (3) via the first cold side water inlet branch pipe (8); the cold fluid equipment body (10) is connected to the cold side water return main pipe (4) via the first cold side water return branch pipe (9); a second stop valve (16) and a second solenoid valve (17) are provided on the surfaces of the first cold side water inlet branch pipe (8) and the first cold side water return branch pipe (9).

4. The parallel plate heat exchanger group according to claim 1, characterized in that: The first connecting device comprises a first connecting pipe (20), the first connecting pipe (20) is connected to the hot side water inlet main pipe (1), a third stop valve (21) and a third solenoid valve (22) are provided on the surface of the first connecting pipe (20), a limiting block (23) is provided in an annular manner at one end of the second hot side water inlet branch pipe (14) close to the first connecting pipe (20), a covering block (24) is rotatably connected to the surface of the second hot side water inlet branch pipe (14), an inner wall of one side of the covering block (24) is tightly pressed against the limiting block (23), an inner wall of the covering block (24) is threadedly connected to one end of the first connecting pipe (20), and a raw tape (25) is wrapped between the inner wall of the covering block (24) and the surface of the first connecting pipe (20).

5. The parallel plate heat exchanger group according to claim 4, characterized in that: A first sealing gasket (26) is provided between the second hot-side water inlet branch pipe (14) and the first connecting pipe (20).

6. The parallel plate heat exchanger group according to claim 5, characterized in that: An annular protrusion (27) is provided on a surface of one side of the first sealing gasket (26) close to the first connecting tube (20), and an annular groove (28) is provided on a surface of one side of the first connecting tube (20) close to the first sealing gasket (26), wherein the annular protrusion (27) and the annular groove (28) match and are engaged with each other.

7. The parallel plate heat exchanger group according to claim 5, characterized in that: A positioning groove (29) is formed in an annular manner on the inner wall of one side of the first connecting pipe (20) close to the second hot-side water inlet branch pipe (14), and a positioning block (30) is formed in an annular manner on the surface of one side of the first sealing gasket (26) close to the positioning groove (29), and the positioning block (30) matches the positioning groove (29).

8. The parallel plate heat exchanger group according to claim 4, characterized in that: A second sealing gasket (31) is provided between the limiting block (23) and the covering block (24).

9. The parallel plate heat exchanger group according to claim 1, characterized in that: The surfaces of the hot-side water inlet main pipe (1), the hot-side water return main pipe (2), the cold-side water inlet main pipe (3) and the cold-side water return main pipe (4) are all connected with a plurality of second connecting pipes (32), and the inner walls of the plurality of second connecting pipes (32) are all threadedly connected with plugs (33).

10. A heat exchange method for a parallel plate heat exchanger group, characterized in that: The parallel plate heat exchanger group is a parallel plate heat exchanger group according to any one of claims 1 to 9, comprising the following steps: S1: First, the raw tape (25) is wrapped around the first connecting pipe (20), and then the covering block (24) is threadedly connected to the corresponding first connecting pipe (20), and the first connecting device, the second connecting device, the third connecting device and the fourth connecting device are installed in sequence; S2: After the installation of the plurality of heat exchanger bodies (11) is completed, the first solenoid valve (13) of the unnecessary hot fluid unit is closed, and the second solenoid valve (17) of the unnecessary cold fluid unit is closed. The first solenoid valve (13) of the single hot fluid device body (7) to be used is opened, and the second solenoid valve (17) of the single cold fluid device body (10) to be used is opened. The hot fluid device body (7) to be used and the cold fluid device body (10) to be used exchange heat through the heat exchanger body (11); S3: The hot fluid in the hot fluid device body (7) enters the hot side water inlet main pipe (1) through the first hot side water inlet branch pipe (5), and then the hot fluid flows back to the hot fluid device body (7) through the first hot side water return branch pipe (6). The cold fluid in the cold fluid device body (10) enters the cold side water inlet main pipe (3) through the first cold side water inlet branch pipe (8), and then heat is exchanged through the heat exchanger body (11). After heat exchange, the cold fluid flows back to the cold fluid device body (10) through the second cold side water return branch pipe (19); S4: If the flow rate of the hot fluid device body (7) and the cold fluid device body (10) is large, the third solenoid valve (22) connected to one or more heat exchanger bodies (11) is opened to increase the parallel heat exchanger body (11) to increase the flow rate to meet the needs of the hot fluid device body (7) and the cold fluid device body (10); S5: If the heat exchanger body (11) needs to be repaired or replaced, the third solenoid valve (22) connected to the heat exchanger body (11) that needs to be repaired or replaced is closed; S6: unscrewing the cover block (24) from the first connecting pipe (20), and then removing the heat exchanger body (11) that needs to be repaired or replaced. At this time, opening another heat exchanger body (11) to replace the heat exchanger body (11) that needs to be repaired or replaced; S7: Program control is performed through the control end to switch the opening and closing of the third solenoid valve (22) on different heat exchanger bodies (11) to achieve the effect of switching heat exchange between different heat exchanger bodies (11).

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