Leak-proof control method of heat exchanger

Abstract

The invention relates to the technical field of heat pumps, in particular to an anti-leakage control method for a heat exchanger. The problem that an existing heat exchanger has the leakage risk is solved. In order to achieve the purpose, one side of the heat exchanger communicates with a liquid outlet pipeline and a liquid return pipeline, a first control valve is arranged on the liquid outlet pipeline, and the anti-leakage control method comprises the steps that the operation pressure of the heat exchanger is obtained; comparing the running pressure with a preset pressure threshold value; and selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result. By means of the mode, the first control valve can prevent high-pressure refrigerants from entering a room from the liquid outlet pipeline, and therefore the high-pressure refrigerants are prevented from damaging the room.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and particularly to a leakage prevention control method for a heat exchanger. Background Art

[0002] The CO2 heat pump system has advantages such as high heating temperature and strong low-temperature heating capacity, and has great application and promotion prospects in household / commercial scenarios such as heat pump water heaters and heat pump floor heating. However, different from traditional refrigerants, when CO2 is used as a refrigerant, the operating pressure exceeds 10 MPa, there is a risk of excessive pressure, and relatively high requirements are imposed on the pressure resistance and safety of the components of the CO2 heat pump system.

[0003] Among them, the heat exchanger component is a key component for heat conversion and is also the position for energy transfer between indoors and outdoors. Water and CO2 are separated by only one wall. Once the heat exchange wall is damaged, high-pressure CO2 will rush into the water system pipeline and then enter the user's indoor space, causing harm indoors.

[0004] Correspondingly, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] In order to solve at least one of the above problems in the prior art, that is, to solve the problem that the existing heat exchanger has a leakage risk, the present application provides a leakage prevention control method for a heat exchanger. The heat exchanger has a refrigerant inlet, a refrigerant outlet, a liquid inlet, and a liquid outlet; the liquid inlet is connected to a return liquid pipeline, the liquid outlet is connected to a liquid discharge pipeline, and a first control valve is provided on the liquid discharge pipeline.

[0006] The leakage prevention control method includes:

[0007] Obtain the operating pressure of the heat exchanger;

[0008] Compare the operating pressure with a preset pressure threshold;

[0009] Based on the comparison result, selectively control the first control valve to block the liquid discharge pipeline.

[0010] In the case of adopting the above technical solution, during the operation of the heat exchanger, the heat exchange wall may be damaged, resulting in the mixing of the fluids on both sides of the heat exchanger. The first control valve can prevent high-pressure refrigerant from entering the indoor through the liquid discharge pipeline, thereby preventing harm to the indoor environment.

[0011] In a preferred technical solution of the above leakage prevention control method, the step of "obtaining the operating pressure of the heat exchanger" includes:

[0012] Obtain at least one of the internal pressure of the heat exchanger, the pressure of the return liquid pipeline, and the pressure of the liquid discharge pipeline.

[0013] In the case of adopting the above technical solution, after the heat exchange wall is damaged, the pressure changes generated at various parts of the heat exchanger are different. By obtaining the pressure changes at different positions, it is possible to more accurately determine whether the heat exchanger is leaking.

[0014] In a preferred technical solution of the above anti-leakage control method, a pressure detection component is provided on the liquid outlet pipeline, and the "obtaining the operating pressure of the heat exchanger" includes:

[0015] Obtaining the pressure of the liquid outlet pipeline.

[0016] In the case of adopting the above technical solution, due to the effect of the liquid flow direction, the pressure change on the liquid outlet pipeline is relatively obvious. By quickly detecting the pressure change on the liquid outlet pipeline through the pressure detection component, it provides a basis for quickly and accurately judging whether the heat exchanger is leaking.

[0017] In a preferred technical solution of the above anti-leakage control method, the step of "selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result" includes:

[0018] When the operating pressure is greater than or equal to the preset pressure threshold, controlling the first control valve to block the liquid outlet pipeline.

[0019] In a preferred technical solution of the above anti-leakage control method, the step of "selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result" further includes:

[0020] When the operating pressure is less than the preset pressure threshold, controlling the first control valve to maintain its current state.

[0021] In a preferred technical solution of the above anti-leakage control method, the anti-leakage control method further includes:

[0022] Based on the operating pressure, determining the pressure growth rate of the heat exchanger;

[0023] Comparing the magnitude of the pressure growth rate with a preset rate threshold;

[0024] When the operating pressure is greater than or equal to the preset pressure threshold and the pressure growth rate is greater than or equal to the preset rate threshold, controlling the first control valve to block the liquid outlet pipeline.

[0025] In the case of adopting the above technical solution, by combining and comparing the pressure and the pressure growth rate, it is possible to more accurately judge whether the heat exchanger is leaking, and prevent the high-pressure refrigerant from flushing into the room through the liquid outlet pipeline after the heat exchanger leaks.

[0026] In a preferred technical solution of the above anti-leakage control method, a second control valve is provided on the liquid return pipeline, and the anti-leakage control method further includes:

[0027] While controlling the first control valve to block the liquid outlet pipeline, control the second control valve to block the liquid return pipeline.

[0028] In the case of adopting the above technical solution, after the heat exchanger leaks, the second control valve can prevent the high-pressure refrigerant from flowing back into the room through the liquid return pipeline.

[0029] In a preferred technical solution of the above anti-leakage control method, the anti-leakage control method further includes:

[0030] After controlling the first control valve to block the liquid outlet pipeline, send out a heat exchanger leakage alarm signal.

[0031] In the case of adopting the above technical solution, after the heat exchanger leaks, on the premise of ensuring indoor safety, send out the signal of heat exchanger leakage to ensure that users can know in time.

[0032] In a preferred technical solution of the above anti-leakage control method, the anti-leakage control method further includes:

[0033] After controlling the first control valve to block the liquid outlet pipeline, stop the refrigerant supply of the heat exchanger.

[0034] In the case of adopting the above technical solution, it is possible to prevent the refrigerant from continuing to enter the heat exchanger after the heat exchanger leaks, thus avoiding potential safety hazards.

[0035] In a preferred technical solution of the above anti-leakage control method, a pressure relief valve is provided on the liquid return pipeline or the liquid outlet pipeline.

[0036] In the case of adopting the above technical solution, the pressure relief valve can release the pressure accumulated on the liquid return pipeline or the liquid outlet pipeline. Brief Description of the Drawings

[0037] The following describes the anti-leakage control method of the heat exchanger of the present application with reference to the drawings and in combination with the CO2 heat pump heating system. In the drawings:

[0038] Figure 1 is a main flow schematic diagram of the anti-leakage control method of the heat exchanger according to an embodiment of the present application;

[0039] Figure 2 is a main step flow schematic diagram of selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result according to an embodiment of the present application;

[0040] Figure 3Logic diagram of a preferred embodiment of the present application;

[0041] Figure 4 Schematic diagram of a CO2 heat pump heating system according to an embodiment of the present application.

[0042] List of Reference Signs

[0043] 10. Heat exchanger; 11. Refrigerant inlet; 12. Refrigerant outlet; 13; Liquid inlet; 14. Liquid outlet; 15. Heat exchange wall; 21. Liquid return pipeline; 22. Liquid outlet pipeline; 23. Water pump; 30. Pressure detection component; 40. Control valve; 60. First pressure relief valve; 70. Check valve; 80. Expansion tank; 90. Second pressure relief valve. Detailed implementation manners

[0044] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application. For example, although this embodiment is introduced in combination with a CO2 heat pump heating system, this is not intended to limit the protection scope of the present application. Without departing from the principle of the present application, those skilled in the art can apply the present application to other application scenarios. For example, the heat exchanger in this embodiment can be arranged in other heat pump systems.

[0045] It should be noted that in the description of the present application, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, "a plurality of" means at least two.

[0046] In addition, it should also be noted that in the description of the present application, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0047] As described in the background art, the CO2 heat pump system has the advantages of high heating temperature and strong low-temperature heating capacity, and has great application and promotion prospects in household / commercial scenarios such as heat pump water heaters and heat pump floor heating. However, different from traditional refrigerants, when CO2 is used as a refrigerant, the operating pressure exceeds 10 MPa, there is a risk of excessive pressure, and high requirements are imposed on the pressure resistance and safety of the components of the CO2 heat pump system.

[0048] Among them, the heat exchanger component is the key component for heat conversion and is also the location for energy transfer between indoors and outdoors. Water and CO2 are only separated by a wall. Once the heat exchange wall is damaged, high-pressure CO2 will rush into the water system pipeline and then enter the user's indoor space, causing harm indoors.

[0049] The following will refer to Figure 1 and Figure 4 to describe the anti-leakage control method of the heat exchanger of the present application. Among them, Figure 1 is the main process schematic diagram of the anti-leakage control method of the heat exchanger of an embodiment of the present application; Figure 4 is the schematic diagram of a CO2 heat pump heating system of an embodiment of the present application.

[0050] To solve the problem of the existing heat exchanger having a leakage risk, the present application provides an anti-leakage control method for a heat exchanger. As shown in Figure 1 and Figure 4 , the heat exchanger 10 has a refrigerant inlet 11, a refrigerant outlet 12, a liquid inlet 13, and a liquid outlet 14; the liquid inlet 13 is connected to the liquid return pipeline 21, the liquid outlet 14 is connected to the liquid outlet pipeline 22, and a first control valve 40 is provided on the liquid outlet pipeline 22.

[0051] As shown in Figure 4 , taking the CO2 heat pump heating system as an example, two cavities are provided inside the heat exchanger 10, which are respectively used to accommodate CO2 and water. The two cavities are separated by a heat exchange wall 15. After the high-pressure CO2 enters the inside of the heat exchanger 10 from the refrigerant inlet 11 and exchanges heat with water, it flows out from the refrigerant outlet 12. Water enters the inside of the heat exchanger 10 from the liquid return pipeline 21 through the liquid inlet 13 and enters the liquid outlet pipeline 22 through the liquid outlet 14. During the operation of the heat exchanger 10, the heat exchange wall 15 may be damaged, resulting in the mixing of high-pressure CO2 and water, and under the action of pressure, the high-pressure CO2 may rush into the liquid outlet pipeline 22.

[0052] The anti-leakage control method of the heat exchanger in the embodiment of the present application mainly includes the following steps:

[0053] S101, obtaining the operating pressure of the heat exchanger;

[0054] S102, comparing the operating pressure with a preset pressure threshold;

[0055] S103, selectively control the first control valve to block the liquid outlet pipeline based on the comparison result.

[0056] Through the method described in the above steps S101 to S103, the operating pressure at the heat exchanger can be obtained in real time or intermittently. Compare the obtained operating pressure with the preset pressure threshold that has been set. Since the operating pressure is very high when CO2 is used as the refrigerant, it is possible to quickly judge whether the heat exchange wall 15 may be damaged according to the pressure change, and block the liquid outlet pipeline 22 after the heat exchange wall 15 is damaged, preventing the high-pressure CO2 from flushing into the room through the liquid outlet pipeline 22 and causing harm to the room.

[0057] In one implementation, the "obtaining the operating pressure of the heat exchanger" in the above step S101 includes:

[0058] Obtain at least one of the internal pressure of the heat exchanger, the pressure of the liquid return pipeline, and the pressure of the liquid outlet pipeline.

[0059] In this implementation, when the heat exchanger 10 is operating, the pressures at various places are not the same. Those skilled in the art can obtain one or more of the pressure in the refrigerant chamber, the pressure in the liquid chamber, the pressure of the liquid return pipeline, and the pressure of the liquid outlet pipeline in the heat exchanger according to the needs. For example, obtain the pressure in the liquid chamber of the heat exchanger and the pressure on the liquid outlet pipeline at the same time, and then compare the obtained different operating pressures with the corresponding preset pressure thresholds, which can more accurately judge whether the heat exchanger leaks. Through the above method, it is possible to judge whether the heat exchange wall 15 may be damaged by comparing the operating pressure at a single place with the preset pressure threshold, or to make the judgment result more accurate by comprehensively comparing the operating pressures at various places with the preset pressure thresholds.

[0060] Preferably, a pressure detection component is provided on the liquid outlet pipeline. The above "obtaining the operating pressure of the heat exchanger" includes:

[0061] Obtain the pressure of the liquid outlet pipeline.

[0062] In this implementation, as Figure 4 shown, a pressure sensor 30 is provided on the liquid outlet pipeline 22, and the pressure on the liquid outlet pipeline 22 can be obtained more quickly through the pressure sensor 30. Of course, Figure 4Only one setting method of the pressure detection component is shown, but its specific setting is not fixed, and those skilled in the art can make changes according to requirements. For example, the pressure sensor 30 can also be set on the liquid return pipeline 21, or inside the heat exchanger 10, at the liquid inlet 13 or the liquid outlet 14. Those skilled in the art can set the pressure sensor 30 at different positions according to requirements. Due to the water flow direction in the liquid return pipeline 21 and the liquid outlet pipeline 22, the pressure change generated on the liquid outlet pipeline 22 is relatively obvious, and the difficulty of setting the pressure sensor 30 on the liquid outlet pipeline 22 is relatively low. Therefore, setting the pressure sensor 30 on the liquid outlet pipeline 22 is a better choice. Of course, multiple pressure sensors 30 can also be set to detect the pressure at different positions, and by comprehensively comparing their magnitudes with the preset pressure threshold, it can be more accurately determined whether the heat exchanger 10 leaks. In addition, the pressure detection component can also be set as a pressure gauge, and the value of the pressure gauge can be directly read through a controller connected to the pressure gauge.

[0063] In one implementation manner, the step of "selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result" in the above step S103 includes:

[0064] When the operating pressure is greater than or equal to the preset pressure threshold, control the first control valve to block the liquid outlet pipeline.

[0065] When the operating pressure is less than the preset pressure threshold, control the first control valve to maintain its current state.

[0066] Continue to refer to Figure 4 , a first control valve 40 is provided on the liquid outlet pipeline 22, wherein the first control valve 40 is set as an electromagnetic valve or other electrically controlled valves. In this implementation manner, taking the operating pressure of the heat exchanger obtained as the pressure on the liquid outlet pipeline 22 as an example, the first control valve 40 is default in the open state, that is, the liquid outlet pipeline 22 remains unblocked. When the operating pressure is greater than or equal to the preset pressure threshold, the first control valve 40 closes, thereby blocking the liquid outlet pipeline to prevent high-pressure CO2 from entering the room through the liquid outlet pipeline 22. When the operating pressure is less than the preset pressure threshold, the first control valve 40 continues to maintain the open state. Among them, the preset pressure threshold can be preset at the factory or manually input by the technician according to the installation site. When the operating pressure is less than this pressure threshold, the first control valve 40 continues to maintain the open state, otherwise, the first control valve 40 is closed to block the liquid outlet pipeline 22.

[0067] Those skilled in the art understand that the above control method is not immutable. For example, when obtaining the operating pressure of the heat exchanger as the pressure in the refrigerant chamber of the heat exchanger 10, after the heat exchanger 10 leaks, that is, the heat exchange wall 15 is damaged, the internal pressure of the refrigerant chamber becomes smaller. At this time, when the operating pressure is less than or equal to the preset pressure threshold, the first control valve 40 closes, and when the operating pressure is greater than or equal to the preset pressure threshold, the first control valve 40 remains open.

[0068] The following refers to Figure 2 , Figure 2 which is a schematic diagram of the main steps for selectively controlling the first control valve to block the liquid outlet pipeline based on the comparison result of an embodiment of the present application.

[0069] In some embodiments, the following steps can be used to more accurately determine whether the heat exchanger leaks, and control the first control valve to block the liquid outlet pipeline when the heat exchanger leaks:

[0070] S201, determine the pressure growth rate of the heat exchanger based on the operating pressure;

[0071] S202, compare the pressure growth rate with the preset rate threshold;

[0072] S203, when the operating pressure is greater than or equal to the preset pressure threshold and the pressure growth rate is greater than or equal to the preset rate threshold, control the first control valve to block the liquid outlet pipeline.

[0073] Since during the normal operation of the heat exchanger, certain pressure changes will also occur inside the heat exchanger or on the liquid outlet pipeline and the liquid return pipeline. In this embodiment, by intermittently obtaining the operating pressure of the heat exchanger, the pressure growth rate can be determined. When both conditions are met, that is, when the operating pressure is greater than or equal to the preset pressure threshold and the pressure growth rate is greater than or equal to the preset rate threshold, control the first control valve to block the liquid outlet pipeline. Through the method described in the above steps S201 to S203, it is possible to more accurately determine whether the heat exchanger leaks and prevent the inconvenience caused by misjudgment.

[0074] Those skilled in the art understand that in this embodiment, only one method of combining the operating pressure and the pressure growth rate to determine whether the heat exchanger leaks is provided, but its setting is not necessary, and those skilled in the art can increase or decrease it according to needs. In an alternative embodiment, without comparing the pressure growth rate, it is also possible to determine whether the heat exchanger leaks only by a single operating pressure or a comprehensive comparison of multiple operating pressures. When comparing the pressure growth rate, it is also possible to compare the pressure growth rates of multiple parts. Additionally, when the obtained operating pressure is the pressure in the refrigerant cavity of the heat exchanger 10, the pressure reduction rate can be determined based on the operating pressure at this location, and when the operating pressure is less than or equal to the preset pressure threshold and the pressure reduction rate is greater than or equal to the preset rate threshold, the first control valve is controlled to block the liquid outlet pipeline.

[0075] In some embodiments, a second control valve is provided on the liquid return pipeline, and a pressure relief valve is provided on the liquid return pipeline or the liquid outlet pipeline. Among them, the second control valve can be the same solenoid valve as the first control valve or other electrically controlled valves. The anti-leakage control method further includes:

[0076] While controlling the first control valve to block the liquid outlet pipeline, control the second control valve to block the liquid return pipeline.

[0077] In this embodiment, after the heat exchanger is damaged, high-pressure CO2 may simultaneously rush into the liquid outlet pipeline and the liquid return pipeline, and the backflow of high-pressure CO2 after rushing into the liquid return pipeline may damage the components upstream of the heat exchanger. Through the above method, it is possible to block the liquid outlet pipeline and the liquid return pipeline simultaneously after determining that the heat exchanger leaks, preventing high-pressure CO2 from rushing into the room or damaging the components upstream of the heat exchanger. After blocking the liquid outlet pipeline and the liquid return pipeline, the pressure of the liquid outlet pipeline and the liquid return pipeline may increase. To ensure safety, a pressure relief valve can be set on the pipeline to release a part of the pressure, as Figure 4 shown, a first pressure relief valve 60 is provided on the liquid return pipeline 21, and an expansion tank 80 and a second pressure relief valve 90 are provided on the liquid outlet pipeline 22. Among them, the expansion tank 80 can also balance the pressure in the liquid outlet pipeline 22 by absorbing moisture or injecting water into the liquid outlet pipeline 22.

[0078] Those skilled in the art understand that the setting of the second control valve is not necessary, as Figure 4As shown in the figure, in one embodiment, the water pump 23 pumps water flow into the liquid return pipeline 21, and then the water flow flows through the one-way valve 70 to the heat exchanger 10. After the heat exchanger 10 leaks, that is, the heat exchange wall 15 is damaged, the high-pressure CO2 enters the liquid outlet pipeline 22 and the liquid return pipeline 21 respectively. The first control valve 40 can block the liquid outlet pipeline 22, and the one-way valve 70 can prevent the high-pressure CO2 from flowing back further and damaging the components upstream of it. Of course, in the case where the one-way valve 70 is not provided, the pressure generated by the water pump 23 can also ensure that the high-pressure CO2 is more likely to flow into the liquid outlet pipeline 22 rather than the liquid return pipeline 21. In addition, the first pressure relief valve 60 and the second pressure relief valve 90 may not be provided. In the case where the first pressure relief valve 60 or the second pressure relief valve 90 is provided, those skilled in the art can also change their specific setting positions. In an alternative embodiment, the second pressure relief valve 90 is provided on the liquid outlet pipeline 22 upstream of the first control valve 40. In another alternative embodiment, only the first pressure relief valve 60 is provided, or multiple pressure relief valves are provided at different positions.

[0079] In one embodiment, the anti-leakage control method further includes:

[0080] After controlling the first control valve to block the liquid outlet pipeline, an alarm signal for heat exchanger leakage is issued, and the refrigerant supply to the heat exchanger is stopped.

[0081] In this embodiment, after the heat exchanger leaks, first, the liquid outlet pipeline is blocked by controlling the first control valve to ensure indoor safety. And on this premise, the refrigerant supply to the heat exchanger can be stopped by controlling the compressor to shut down, etc., to prevent further leakage of high-pressure CO2, and at the same time, an alarm signal for heat exchanger leakage is sent out to notify the user faster. Among them, the heat exchanger alarm signal can be a sound alarm, a light alarm, or can be completed by sending information to the terminal device. Those skilled in the art understand that the ways of sending out the heat exchanger leakage alarm signal and stopping the refrigerant supply to the heat exchanger are not fixed, and both can be not set, or not set at the same time, or those skilled in the art can adjust their execution order according to the requirements.

[0082] Next, refer to Figure 3 to introduce a preferred embodiment of the anti-leakage control method of the heat exchanger of the present application. Figure 3 This is the logic diagram of a preferred embodiment of the present application.

[0083] As Figure 3 shown, in a possible embodiment,

[0084] S301, obtain the operating pressure of the heat exchanger.

[0085] S302, based on the operating pressure, determine the pressure growth rate of the heat exchanger.

[0086] S303. Compare the magnitudes of the operating pressure and the preset pressure threshold value. If it holds that the operating pressure is greater than or equal to the preset pressure threshold value, then execute S304; otherwise, end the judgment program.

[0087] S304. Compare the magnitudes of the pressure growth rate and the preset rate threshold value. If it holds that the pressure growth rate is greater than or equal to the preset rate threshold value, then execute S305; otherwise, end the judgment program.

[0088] S305. Control the first control valve to close.

[0089] S306. Control the second control valve to close.

[0090] S307. Send out an alarm signal for heat exchanger leakage.

[0091] S308. Control the compressor to stop operating.

[0092] Through the method described in the above steps S301 to S308, comprehensively comparing the operating pressure and the pressure growth rate can more accurately determine whether the heat exchanger leaks, thereby preventing the inconvenience caused by misjudgment. When it is determined that the heat exchanger leaks, by controlling the first control valve and the second control valve to close, the liquid outlet pipeline and the liquid return pipeline are blocked respectively, preventing high-pressure CO2 from flushing into the room through the liquid outlet pipeline or the liquid return pipeline, and avoiding harm to the room. On the premise of ensuring safety, an alarm signal is sent to the outside to remind technicians to repair as soon as possible, and the refrigerant supply of the heat exchanger can be stopped by controlling the compressor to shut down and other means, thereby preventing more high-pressure CO2 from entering the heat exchanger and some water vapor from entering the refrigerant path, thus avoiding potential safety hazards.

[0093] Those skilled in the art understand that the execution order of the above control method is not fixed. Those skilled in the art can adjust its execution order or delete the above steps according to requirements, as long as the normal functions of this application are not affected. In an alternative embodiment, the pressure growth rate and the preset rate threshold can be compared first, and then the operating pressure and the preset pressure threshold can be compared. Of course, it is also possible not to compare the pressure growth rate and the preset rate threshold. Among them, the preset pressure threshold can also be a pressure range measured by a technician. When the operating pressure is less than this pressure range, the comparison of the pressure growth rate and the preset rate threshold can be omitted, and the first control valve remains open. When the operating pressure is within this range, the pressure growth rate and the preset rate threshold are compared, and whether to close the first control valve and the second control valve is determined according to the comparison result. When the operating pressure is greater than this pressure range, the first control valve and the second control valve can be directly closed without comparing the pressure growth rate and the preset rate threshold. In another alternative embodiment, the first control valve and the second control valve can be closed simultaneously, and the refrigerant supply to the heat exchanger can also be stopped first and then the heat exchanger leakage alarm signal can be sent. In another alternative embodiment, after obtaining the operating pressure of the heat exchanger, the operating pressure and the preset pressure threshold are compared first. After it is established that the operating pressure is greater than or equal to the preset pressure threshold, the pressure growth rate of the heat exchanger is then determined, and then the pressure growth rate and the preset rate threshold are compared. When the pressure growth rate is greater than or equal to the preset rate threshold, the first control valve and the second control valve are controlled to close.

[0094] Those skilled in the art will appreciate that although some of the embodiments described herein include certain features included in other embodiments but not others, the combination of features of different embodiments is within the scope of this application and forms different embodiments. For example, in the claims of this application, any one of the claimed embodiments can be used in any combination.

[0095] So far, the technical solutions of this application have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of this application is obviously not limited to these specific embodiments. Without departing from the principle of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this application.

Claims

1. A leakage prevention control method for a heat exchanger, characterized in that The heat exchanger has a refrigerant inlet, a refrigerant outlet, a liquid inlet, and a liquid outlet; the liquid inlet is communicated with a liquid return pipeline, the liquid outlet is communicated with a liquid discharge pipeline, and a first control valve is arranged on the liquid discharge pipeline; The anti-leakage control method includes: Obtaining the operating pressure of the heat exchanger; Comparing the magnitude of the operating pressure with a preset pressure threshold; Based on the comparison result, selectively controlling the first control valve to block the liquid discharge pipeline.

2. The anti-leakage control method according to claim 1, wherein The "obtaining the operating pressure of the heat exchanger" includes: Obtaining at least one of the internal pressure of the heat exchanger, the pressure of the liquid return pipeline, and the pressure of the liquid discharge pipeline.

3. The anti-leakage control method according to claim 2, characterized in that, A pressure detection component is arranged on the liquid discharge pipeline, and the "obtaining the operating pressure of the heat exchanger" includes: Obtaining the pressure of the liquid discharge pipeline.

4. The anti-leakage control method according to claim 1, wherein The step of "based on the comparison result, selectively controlling the first control valve to block the liquid discharge pipeline" includes: When the operating pressure is greater than or equal to the preset pressure threshold, controlling the first control valve to block the liquid discharge pipeline.

5. The anti-leakage control method according to claim 1, wherein The step of "based on the comparison result, selectively controlling the first control valve to block the liquid discharge pipeline" further includes: When the operating pressure is less than the preset pressure threshold, controlling the first control valve to maintain the current state.

6. The anti-leakage control method according to claim 4, wherein The anti-leakage control method further includes: Based on the operating pressure, determining the pressure growth rate of the heat exchanger; Comparing the magnitude of the pressure growth rate with a preset rate threshold; When the operating pressure is greater than or equal to the preset pressure threshold and the pressure growth rate is greater than or equal to the preset rate threshold, controlling the first control valve to block the liquid discharge pipeline.

7. The anti-leakage control method according to claim 6, characterized in that A second control valve is arranged on the liquid return pipeline, and the anti-leakage control method further includes: While controlling the first control valve to block the liquid discharge pipeline, controlling the second control valve to block the liquid return pipeline.

8. The anti-leakage control method according to claim 1, wherein The anti-leakage control method further includes: After controlling the first control valve to block the liquid discharge pipeline, sending out a heat exchanger leakage alarm signal.

9. The anti-leakage control method according to claim 1, characterized in that The anti-leakage control method further includes: After controlling the first control valve to block the liquid discharge pipeline, stopping the refrigerant supply of the heat exchanger.

10. The anti-leakage control method according to claim 1, characterized in that A pressure relief valve is arranged on the liquid return pipeline or the liquid discharge pipeline.

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