Four-pipe heat pump unit

Abstract

The utility model relates to a four-pipe heat pump unit. The four-pipe heat pump unit comprises an injection assembly and a plurality of unit modules. The four-pipe heat pump unit has multiple working modes, at least one unit module is in a non-working state in each working mode, and a circulating system used for circulating refrigerants is formed through the other unit modules in the working state. The injection assembly comprises a working state and a non-working state. And in a non-working state, the injection assembly is not communicated with the circulating system. The injection assembly is used for being switched into the working state under the set condition and communicating with the circulation system so as to guide the refrigerant from the unit module in the non-working state back to the circulation system. According to the structural arrangement of the four-pipe heat pump unit, the situations of system alarm, shutdown and the like caused by insufficient coolant supply in a circulating system are avoided, the working mode of the injection assembly is more direct and simpler, and when the injection assembly is in the working state, the four-pipe heat pump unit does not need to be paused or switched to other modes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioning systems, and in particular to a four-pipe heat pump unit. BACKGROUND

[0002] The working system of the four-pipe heat pump unit includes multiple heat exchangers. In the working process, each mode has a heat exchanger in a non-working state. Under certain environmental conditions, such as heat recovery mode at low ambient temperature or heating mode at high ambient temperature, the sealing problem in the four-way valve may cause refrigerant leakage. Over time, this leakage may gradually transfer refrigerant to the heat exchanger in the non-working state, thereby reducing the amount of refrigerant participating in the system circulation, causing insufficient liquid supply, and possibly triggering system alarms and shutdowns, while also increasing the risk of heat exchanger freeze. SUMMARY

[0003] The present application provides a four-pipe heat pump unit to solve some or all of the deficiencies in the related art.

[0004] The present application provides a four-pipe heat pump unit, comprising an ejector assembly and multiple unit modules. The four-pipe heat pump unit has multiple working modes, each working mode having at least one unit module in a non-working state and forming a circulation system for circulating refrigerant through the remaining unit modules in a working state.

[0005] The ejector assembly includes a working state and a non-working state. In the non-working state, the ejector assembly is not connected to the circulation system. The ejector assembly is used to switch to the working state and connect to the circulation system under a set condition to guide refrigerant from the unit module in the non-working state back to the circulation system.

[0006] Optionally, the unit module includes a compressor, a plate heat exchanger, an oil separator, a fin heat exchanger, and an evaporator.

[0007] The working mode includes a heating mode, and the set condition is that the suction saturation temperature of the compressor is greater than the outlet water temperature of the evaporator. In the heating mode, the evaporator is in a non-working state, and the compressor, plate heat exchanger, oil separator, and fin heat exchanger form the circulation system; and / or the working mode includes a heat recovery mode, and the set condition is that the suction saturation temperature of the compressor is greater than the ambient temperature. In the heat recovery mode, the fin heat exchanger is in a non-working state, and the compressor, plate heat exchanger, oil separator, and evaporator form the circulation system.

[0008] Optionally, the ejector assembly comprises a first end, a second end and a third end. The first end is connectable to and disconnectable from the oil separator. The second end is connectable to and disconnectable from the evaporator and the finned heat exchanger respectively. The third end is connectable to and disconnectable from the evaporator and the finned heat exchanger respectively.

[0009] In the heating mode, when the corresponding set condition is satisfied, the first end is connected to the oil separator, the second end is disconnected from the evaporator and connected to the finned heat exchanger, and the third end is connected to the evaporator and disconnected from the finned heat exchanger; and / or, in the heat recovery mode, when the corresponding set condition is satisfied, the first end is connected to the oil separator, the second end is connected to the evaporator and disconnected from the finned heat exchanger, and the third end is disconnected from the evaporator and connected to the finned heat exchanger.

[0010] Optionally, the ejector assembly comprises an ejector and first, second and third solenoid valves. The first solenoid valve is connected between the first end and the oil separator. The second solenoid valve is connected between the third end and the finned heat exchanger. The third solenoid valve is connected between the third end and the evaporator.

[0011] In the heating mode, when the corresponding set condition is satisfied, the second solenoid valve is closed, and the first and third solenoid valves are opened; and / or, in the heat recovery mode, when the corresponding set condition is satisfied, the third solenoid valve is closed, and the first and second solenoid valves are opened.

[0012] Optionally, the ejector assembly comprises a first end, a second end and a third end. The first end is connectable to and disconnectable from the oil separator. The second end is connectable to and disconnectable from the evaporator and the finned heat exchanger respectively. The third end is connectable to and disconnectable from the evaporator and the finned heat exchanger respectively.

[0013] In the heating mode, when the corresponding set condition is satisfied, the first end is connected to the oil separator, the second end is disconnected from the evaporator and connected to the finned heat exchanger, and the third end is connected to the evaporator and disconnected from the finned heat exchanger; and / or, in the heat recovery mode, when the corresponding set condition is satisfied, the first end is connected to the oil separator, the second end is connected to the evaporator and disconnected from the finned heat exchanger, and the third end is disconnected from the evaporator and connected to the finned heat exchanger.

[0014] Optionally, the ejector assembly comprises an ejector and a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve and a fifth electromagnetic valve. The first electromagnetic valve is connected between the first end and the oil separator. The second electromagnetic valve is arranged to be connected between the third end and the finned heat exchanger. The third electromagnetic valve is connected between the second end and the finned heat exchanger. The fourth electromagnetic valve is connected between the second end and the evaporator. The fifth electromagnetic valve is connected between the third end and the evaporator.

[0015] In the heating mode, when the corresponding set condition is met, the second electromagnetic valve and the fourth electromagnetic valve are closed, and the first electromagnetic valve, the third electromagnetic valve and the fifth electromagnetic valve are opened; and / or in the heat recovery mode, when the corresponding set condition is met, the third electromagnetic valve and the fifth electromagnetic valve are closed, and the first electromagnetic valve, the second electromagnetic valve and the fourth electromagnetic valve are opened.

[0016] Optionally, the four-pipe heat pump unit further comprises a pre-distributor. The pre-distributor is connected between the finned heat exchanger and the third electromagnetic valve.

[0017] Optionally, the four-pipe heat pump unit further comprises a controller, a sensor, a first four-way reversing valve, a second four-way reversing valve and a defrosting electromagnetic valve. The ejector assembly, the sensor, the first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve are electrically connected to the controller. The first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve are connected between the plate heat exchanger, the oil separator, the finned heat exchanger and the evaporator. The sensor is configured to acquire at least one of the suction saturation temperature of the compressor, the outlet water temperature of the evaporator and the ambient temperature. The controller is configured to control the energization state of the first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve to control the working mode of the four-pipe heat pump unit, and to control the ejector assembly to switch between the working state and the non-working state according to the detection information of the sensor.

[0018] Optionally, the ejector assembly comprises an ejector, and the ejector comprises a body and a nozzle. The body is internally formed with a mixing cavity, and the side wall of the body is provided with an inlet end, a discharge end and an introduction end which are in communication with the mixing cavity. The nozzle extends into the mixing cavity from the inlet end and faces the discharge end.

[0019] Optionally, the running time of the ejector assembly is negatively correlated with the pressure ratio of the four-pipe heat pump unit.

[0020] The technical scheme provided by the embodiments of the present application can have the following beneficial effects:

[0021] From the above embodiments, the structure of the four-pipe heat pump unit of the present application can guide the refrigerant in the unit module in a non-working state back to the circulating system through the ejector assembly in different working modes, thereby avoiding the insufficient supply of coolant in the circulating system, causing system alarm, shutdown and other conditions, and the working mode of the ejector assembly is more direct and simple. When the ejector assembly is in working state, the four-pipe heat pump unit does not need to be suspended or switched to other modes. As can be seen, the four-pipe heat pump unit of the present application has higher continuity and stability when working, effectively reduces energy loss during operation, avoids large water temperature fluctuations, and thus ensures the user experience. In addition, the structure of the ejector assembly is simple, the production cost is low, and the control process of the system also has high convenience, effectively expanding the application range of the four-pipe heat pump unit.

[0022] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The system framework diagram of the four-pipe heat pump unit in an embodiment of the present application;

[0025] Figure 2 The system framework diagram of the four-pipe heat pump unit in another embodiment of the present application;

[0026] Figure 3 The structure schematic diagram of the ejector in an embodiment of the present application;

[0027] Figure 4 The relationship curve diagram between the running time and pressure ratio of the ejector in an embodiment of the present application;

[0028] Figure 5 The intermittent working schematic diagram of the ejector in an embodiment of the present application.

[0029] Explanation of reference signs:

[0030] 100. Four-pipe heat pump unit; 1. Ejector assembly; 11. First end; 12. Second end; 13. Third end; 14. Ejector; 141. Body; 1411. Mixing chamber; 141a. Inlet end; 141b. Discharge end; 141c. Inlet end; 142. Nozzle; 15. First solenoid valve; 16. Second solenoid valve; 17. Third solenoid valve; 18. Fourth solenoid valve; 19. Fifth solenoid valve; 2. Unit module; 21. Compressor; 22. Plate heat exchanger; 23. Oil separator; 24. Finned heat exchanger; 25. Evaporator; 3. Pre-distributor; 4. First four-way reversing valve; 5. Second four-way reversing valve; 6. Defrosting solenoid valve. Detailed Implementation

[0031] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0032] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0033] like Figure 1 and Figure 2 As shown, this application provides a four-pipe heat pump unit 100, including: an ejector assembly 1 and multiple unit modules 2. The four-pipe heat pump unit 100 has multiple operating modes, in each operating mode at least one unit module 2 is in a non-operating state, and a circulation system for refrigerant circulation is formed by the remaining unit modules 2 in the operating state.

[0034] The ejector assembly 1 has an operating state and a non-operating state. In the non-operating state, the ejector assembly 1 is not connected to the circulation system. The ejector assembly 1 is used to switch to the operating state and connect to the circulation system under set conditions in order to guide the refrigerant from the non-operating unit module 2 back to the circulation system.

[0035] In actual working scenarios, in each working mode of the four-pipe heat pump unit 100, there will be a unit module 2 in a non-working state, and due to the sealing problem inside the circulating system, the refrigerant in the circulating system may leak into the unit module 2 in the non-working state, thereby causing insufficient refrigerant in the circulating system, triggering unit alarm and other problems. The structure of the four-pipe heat pump unit 100 in the present application can guide the refrigerant in the unit module 2 in the non-working state back to the circulating system through the injection assembly 1 in different working modes, thereby avoiding insufficient refrigerant supply in the circulating system, causing system alarm, shutdown and other conditions, and the working mode of the injection assembly 1 is more direct and simple. When the injection assembly 1 is in the working state, the four-pipe heat pump unit 100 does not need to be suspended or switched to other modes. As can be seen, the four-pipe heat pump unit 100 of the present application has higher continuity and stability when working, effectively reduces energy loss during operation, avoids large temperature fluctuations, and thus ensures the user's experience. In addition, the structure of the injection assembly 1 is simple, the production cost is low, and the control process of the system also has high convenience, effectively expanding the application range of the four-pipe heat pump unit 100.

[0036] In an optional embodiment, the unit module 2 includes a compressor 21, a plate heat exchanger 22, an oil separator 23, a fin heat exchanger 24, and an evaporator 25.

[0037] The working mode of the four-pipe heat pump unit 100 includes a heating mode, at this time, the set condition is that the suction saturation temperature of the compressor 21 is greater than the outlet water temperature of the evaporator 25. In this mode, the evaporator 25 is in a non-working state, and the compressor 21, the plate heat exchanger 22, the oil separator 23 and the fin heat exchanger 24 form a circulating system.

[0038] In addition, the working mode of the four-pipe heat pump unit 100 also includes a heat recovery mode, at this time, the set condition is that the suction saturation temperature of the compressor 21 is greater than the ambient temperature. In this mode, the fin heat exchanger 24 is in a non-working state, and the compressor 21, the plate heat exchanger 22, the oil separator 23 and the evaporator 25 form a circulating system.

[0039] In an actual working scenario, when the four-pipe heat pump unit 100 is in the heating mode, the evaporator 25 is in a non-working state. If the system detects that the suction saturation temperature of the compressor 21 is greater than the outlet water temperature of the evaporator 25 at this time, it can be proved that the refrigerant in the circulating system has leaked into the evaporator 25. Therefore, the injection assembly 1 enters the working state according to the set condition, and then the refrigerant in the evaporator 25 is guided back into the circulating system. Similarly, when the four-pipe heat pump unit 100 is in the heat recovery mode, the finned heat exchanger 24 is in a non-working state. If the system detects that the suction saturation temperature of the compressor 21 is greater than the ambient temperature at this time, it can be proved that the refrigerant in the circulating system has leaked into the finned heat exchanger 24. Therefore, the injection assembly 1 also enters the working state according to the set condition, and then the refrigerant in the finned heat exchanger 24 is guided back into the circulating system.

[0040] Therefore, the four-pipe heat pump unit 100 of the present application has the advantages of simple and effective structure, high autonomy, and does not need to interrupt the current working mode of the four-pipe heat pump unit 100, effectively improving the continuity and stability of the working process of the four-pipe heat pump unit 100, and thus ensuring the user's experience.

[0041] It should be noted that in the scheme described in the present embodiment, the four-pipe heat pump unit 100 simultaneously includes the heating mode, the cooling mode, the heat recovery mode and the defrosting mode. In some other optional embodiments, only one or several of the above working modes can be included, or other modes other than the above working modes can be included, and therefore the present application does not limit this. However, the scheme of guiding the refrigerant in the unit module 2 in a non-working state back into the circulating system by setting the injection assembly 1 should fall within the scope described in the present application.

[0042] As shown in FIG. 1, the four-pipe heat pump unit 100 includes a compressor 21, an oil separator 23, an injection assembly 1, an evaporator 25, a condenser 22, a finned heat exchanger 24, and a valve 26. Figure 1 As shown in FIG. 2, in an optional embodiment, the injection assembly 1 includes a first end 11, a second end 12 and a third end 13. The first end 11 is connected to the oil separator 23 in an on-off manner. The second end 12 is connected to the compressor 21. The third end 13 is connected to the evaporator 25 and the finned heat exchanger 24 in an on-off manner, respectively.

[0043] In the heating mode, when the corresponding set condition is met, the first end 11 is in communication with the oil separator 23, and the third end 13 is in communication with the evaporator 25 and is disconnected from the finned heat exchanger 24.

[0044] In combination with the above-described content and the Figure 1It can be seen that in the heating mode, when the set condition is triggered, it indicates that the refrigerant has leaked into the evaporator 25. At this time, the first end 11 of the injection assembly 1 is in communication with the oil separator 23, the third end 13 is in communication with the evaporator 25, and is disconnected with the finned heat exchanger 24, that is, the refrigerant in the evaporator 25 can be injected out through the high-pressure fluid in the oil separator 23 and flow into the compressor 21 through the second end 12, and then into the circulating system to continue to work.

[0045] And in the heat recovery mode, when the corresponding set condition is met, the first end 11 is in communication with the oil separator 23, the third end 13 is disconnected with the evaporator 25 and is in communication with the finned heat exchanger 24.

[0046] Similarly, in the heat recovery mode, when the set condition is triggered, it indicates that the refrigerant has leaked into the finned heat exchanger 24. At this time, the third end 13 of the injection assembly 1 is switched to be in communication with the finned heat exchanger 24 and is disconnected with the evaporator 25, that is, the refrigerant in the finned heat exchanger 24 can be injected out through the high-pressure fluid in the oil separator 23 and flow into the compressor 21 through the second end 12, and then into the circulating system to continue to work.

[0047] Therefore, the four-pipe heat pump unit 100 effectively improves the working efficiency and autonomy in the working process by the setting of the injection assembly 1, and also ensures that the circulating system has sufficient refrigerant supply, so that the unit alarm and shutdown are not triggered, thereby ensuring the user's experience.

[0048] As shown in Figure 1 In an optional embodiment, the injection assembly 1 includes an ejector 14 and first, second and third electromagnetic valves 15, 16 and 17. The first electromagnetic valve 15 is connected between the first end 11 and the oil separator 23. The second electromagnetic valve 16 is arranged to be connected between the third end 13 and the finned heat exchanger 24. The third electromagnetic valve 17 is connected between the third end 13 and the evaporator 25.

[0049] When the four-pipe heat pump unit 100 triggers the corresponding set condition, the first electromagnetic valve 15 is opened to enable the ejector 14 to access the circulating system. Then according to the specific working condition, the second and third electromagnetic valves 16 and 17 are opened correspondingly to access the unit module 2 in the non-working state, and then guide the leaked refrigerant back to the circulating system. The four-pipe heat pump unit 100 of the present application only needs to control the opening and closing of the first, second and third electromagnetic valves 15, 16 and 17 to achieve the purpose of guiding the refrigerant in the non-working unit module 2 back to the circulating system. It can be seen that the structure of the injection assembly 1 is simple and effective, and its working efficiency is high and the working process is stable, which effectively saves the production and use costs.

[0050] In a specific use scenario, when the four-pipe heat pump machine is in a heating mode and the corresponding set condition is met, the ejector assembly 1 controls the second electromagnetic valve 16 to be closed and the first electromagnetic valve 15 and the third electromagnetic valve 17 to be opened in response to the set condition.

[0051] When the four-pipe heat pump machine is in a heat recovery mode and the corresponding set condition is met, the ejector assembly 1 controls the third electromagnetic valve 17 to be closed and the first electromagnetic valve 15 and the second electromagnetic valve 16 to be opened in response to the set condition.

[0052] In actual use, when the four-pipe heat pump machine is in the heating mode, the ejector assembly 1 can control the opening and closing of the electromagnetic valves to inject the refrigerant in the evaporator 25 in a non-working state into the compressor 21. When the four-pipe heat pump machine is in the heat recovery mode, the ejector assembly 1 can also control the opening and closing of the electromagnetic valves to inject the refrigerant in the finned heat exchanger 24 in a non-working state into the compressor 21. As can be seen, the ejector assembly 1 has high autonomy and working efficiency, and can inject different unit modules 2 according to the corresponding working scenario, thereby ensuring the stable operation of the entire circulating system.

[0053] As shown in FIG. 1, in an optional embodiment, the second end 12 is connected to the evaporator 25 and the finned heat exchanger 24 in a breakable manner. Figure 2

[0054] In this embodiment, the second end 12 of the ejector assembly 1 is arranged to be connected to the evaporator 25 and the finned heat exchanger 24 in a breakable manner. Therefore, when the four-pipe heat pump unit 100 is in the heating mode and the corresponding set condition is met, the first end 11 is in communication with the oil separator 23, the second end 12 is disconnected from the evaporator 25 and connected to the finned heat exchanger 24, and the third end 13 is connected to the evaporator 25 and disconnected from the finned heat exchanger 24, so that the leaked refrigerant can be injected from the evaporator 25 to the finned heat exchanger 24.

[0055] Similarly, when the four-pipe heat pump unit 100 is in the heat recovery mode and the corresponding set condition is met, the first end 11 is in communication with the oil separator 23, the second end 12 is connected to the evaporator 25 and disconnected from the finned heat exchanger 24, and the third end 13 is disconnected from the evaporator 25 and connected to the finned heat exchanger 24, so that the leaked refrigerant can be injected from the finned heat exchanger 24 to the evaporator 25.

[0056] In other words, in this embodiment, when the four-pipe heat pump unit 100 is in different working modes, the structure of the ejector assembly 1 can directly inject refrigerant between the evaporator 25 and the finned heat exchanger 24, and it can be seen that the structure of the ejector assembly 1 in this embodiment has better adaptability and wider application range. ​

[0057] As Figure 2 shown, in an optional embodiment, the ejector assembly 1 includes an ejector 14 and a first electromagnetic valve 15, a second electromagnetic valve 16, a third electromagnetic valve 17, a fourth electromagnetic valve 18 and a fifth electromagnetic valve 19. The first electromagnetic valve 15 is connected between the first end 11 and an oil separator 23. The second electromagnetic valve 16 is arranged to be connected between the third end 13 and a finned heat exchanger 24. The third electromagnetic valve 17 is connected between the second end 12 and the finned heat exchanger 24. The fourth electromagnetic valve 18 is connected between the second end 12 and an evaporator 25. The fifth electromagnetic valve 19 is connected between the third end 13 and the evaporator 25.

[0058] In the heating mode, when the corresponding set conditions are met, the second electromagnetic valve 16 and the fourth electromagnetic valve 18 are closed, and the first electromagnetic valve 15, the third electromagnetic valve 17 and the fifth electromagnetic valve 19 are opened.

[0059] In the heat recovery mode, when the corresponding set conditions are met, the third electromagnetic valve 17 and the fifth electromagnetic valve 19 are closed, and the first electromagnetic valve 15, the second electromagnetic valve 16 and the fourth electromagnetic valve 18 are opened.

[0060] In actual working scenarios, when the four-pipe heat pump unit 100 is in the heating mode and the corresponding set conditions are triggered, the first electromagnetic valve 15 is opened to connect the ejector 14 to the circulating system, and then the third electromagnetic valve 17 and the fifth electromagnetic valve 19 are opened to connect the second end 12 to the finned heat exchanger 24 and the third end 13 to the evaporator 25, thereby connecting the non-working evaporator 25 and guiding the leaked refrigerant to the finned heat exchanger 24. Similarly, when the four-pipe heat pump unit 100 is in the heat recovery mode and the corresponding set conditions are triggered, the first electromagnetic valve 15 is opened to connect the ejector 14 to the circulating system, and then the second electromagnetic valve 16 and the fourth electromagnetic valve 18 are opened to connect the second end 12 to the evaporator 25 and the third end 13 to the finned heat exchanger 24, thereby connecting the non-working finned heat exchanger 24 and guiding the leaked refrigerant to the evaporator 25.

[0061] In this embodiment, the four-pipe heat pump unit 100 can eject the leaked refrigerant from the evaporator 25 to the finned heat exchanger 24 or from the finned heat exchanger 24 to the evaporator 25 by controlling the opening and closing of the first electromagnetic valve 15, the second electromagnetic valve 16, the third electromagnetic valve 17, the fourth electromagnetic valve 18 and the fifth electromagnetic valve 19, thereby achieving the purpose of guiding the refrigerant in the non-working unit module 2 back to the circulating system, effectively expanding the application range and working efficiency of the ejector assembly 1.

[0062] As Figure 2As shown, in an optional embodiment, the four-pipe heat pump unit 100 further comprises a pre-distributor 3. The pre-distributor 3 is connected between the finned heat exchanger 24 and the third solenoid valve 17.

[0063] When the injection assembly 1 guides the refrigerant to flow from the evaporator 25 into the finned heat exchanger 24, the pre-distributor 3 can better distribute the refrigerant into the finned heat exchanger 24, thereby improving the working efficiency of the finned heat exchanger 24, and also playing a certain protection effect on the compressor 21, thus further improving the working efficiency, stability, reliability and safety of the four-pipe heat pump unit 100.

[0064] In an optional embodiment, the four-pipe heat pump unit 100 further comprises a controller, a sensor, a first four-way reversing valve 4, a second four-way reversing valve 5 and a defrosting solenoid valve 6. The injection assembly 1, the sensor, the first four-way reversing valve 4, the second four-way reversing valve 5 and the defrosting solenoid valve 6 are electrically connected to the controller. The first four-way reversing valve 4, the second four-way reversing valve 5 and the defrosting solenoid valve 6 are connected between the plate heat exchanger 22, the oil separator 23, the finned heat exchanger 24 and the evaporator 25. The sensor is used to obtain at least one of the suction saturation temperature of the compressor 21, the outlet water temperature of the evaporator 25 and the ambient temperature. The controller is used to control the energization state of the first four-way reversing valve 4, the second four-way reversing valve 5 and the defrosting solenoid valve 6 to control the working mode of the four-pipe heat pump unit 100, and to control the injection assembly 1 to switch between the working state and the non-working state according to the detection information of the sensor.

[0065] It should be noted that in the actual application process of the four-pipe heat pump unit 100, the sensor can be configured as a pressure sensor, so as to obtain the suction saturation temperature of the compressor 21 by detecting the suction pressure of the compressor 21. Of course, the sensor can also be configured as a temperature sensor, so as to directly detect the outlet water temperature of the evaporator 25 and the ambient temperature. Therefore, the present application does not limit this.

[0066] The controller of the four-pipe heat pump unit 100 receives the detection information sent by the sensor, and judges whether the injection assembly 1 needs to enter the working state according to the specific working mode of the current four-pipe heat pump unit 100, and then injects the leaked refrigerant.

[0067] In the working process, when the four-pipe heat pump unit 100 is in the cooling mode, the first four-way reversing valve 4 and the second four-way reversing valve 5 are not energized, at this time the controller controls the injection assembly 1 to be in the non-working state, and controls the defrosting solenoid valve 6 to be closed (i.e. not energized).

[0068] When the four-pipe heat pump unit 100 is in heating mode, both the first four-way reversing valve 4 and the second four-way reversing valve 5 are energized. At this time, the controller makes a judgment based on the detection information sent by the sensor. When the monitoring information meets the preset conditions, the controller controls the ejector assembly 1 to connect to the circulation system, that is, to be in working state.

[0069] When the four-pipe heat pump unit 100 is in heat recovery mode, the first four-way reversing valve 4 is energized, while the second four-way reversing valve 5 is de-energized. Similarly, the controller makes a judgment based on the detection information sent by the sensor. When the monitoring information meets the preset conditions, it controls the ejector assembly 1 to connect to the circulation system, that is, to be in working state.

[0070] When the four-pipe heat pump unit 100 is in defrost mode, neither the first four-way reversing valve 4 nor the second four-way reversing valve 5 is energized. At this time, the controller controls the ejector assembly 1 to be in a non-working state and controls the defrost solenoid valve 6 to open.

[0071] like Figure 3 As shown, in an optional embodiment, the ejector 14 includes a body 141 and a nozzle 142. A mixing chamber 1411 is formed inside the body 141, and the sidewall of the body 141 has an inlet end 141a, an outlet end 141b, and an inlet end 141c communicating with the mixing chamber 1411. The nozzle 142 extends into the mixing chamber 1411 from the inlet end 141a and faces the outlet end 141b.

[0072] Combination Figure 3 As can be seen, the ejector 14 uses the high-pressure fluid at the inlet end 141a to eject the fluid (i.e., refrigerant) at the inlet end 141c into the mixing chamber 1411, and then discharges it through the outlet end 141b. Therefore, the ejector 14 has a simple and effective structure. While improving the working efficiency and stability of the four-pipe heat pump unit 100, it also effectively controls its production and operating costs, thus significantly improving its practicality and expanding its application range.

[0073] like Figure 4 As shown, in an optional embodiment, the runtime of the ejector assembly 1 is negatively correlated with the pressure ratio of the four-pipe heat pump unit 100. In the figure, the horizontal axis (PR) represents the pressure ratio of the four-pipe heat pump unit 100, and the vertical axis (TIME) represents the runtime of the ejector assembly 1.

[0074] from Figure 4As can be seen, the four-pipe heat pump unit 100 can determine the operation time of the ejector 14 according to the pressure ratio of the system when the system is running. Specifically, when the four-pipe heat pump unit 100 is running, the smaller the pressure ratio PR of the overall system, the longer the operation time TIME of the control ejector 14, and the larger the pressure ratio PR of the system, the shorter the operation time TIME of the control ejector 14. For example, when the pressure ratio is between PR1-PR2, the operation time of the control ejector 14 is T3; and when the pressure ratio is between PR3-PR4, the operation time of the control ejector 14 is T1. The leakage amount of the refrigerant can be determined by the pressure ratio of the system, so as to control the operation time of the ejector 14 according to different situations, so as to ensure that enough refrigerant can be injected back into the circulating system, and the stability of the system when running is ensured.

[0075] The application also provides a control method of the four-pipe heat pump unit 100, which comprises:

[0076] S1, when the four-pipe heat pump unit 100 is in the first type of set working mode, the control ejector assembly 1 is in a non-working state;

[0077] S2, when the four-pipe heat pump unit 100 is in the second type of set working mode, and the set operation parameter of the unit module 2 reaches the set condition, the control ejector assembly 1 is switched from the non-working state to the working state, so that the ejector assembly 1 is in communication with the circulating system, and the refrigerant in the unit module 2 in the non-working state is guided back to the circulating system.

[0078] In the control method, when the four-pipe heat pump unit 100 is in different working modes, the refrigerant in the unit module 2 in the non-working state can be guided back to the circulating system by controlling the ejector assembly 1 to enter the working state, so as to avoid the insufficient supply of coolant in the circulating system, causing system alarm, shutdown and other situations, and the control method is direct and simple. When the ejector assembly 1 is in the working state, the four-pipe heat pump unit 100 does not need to be paused or switched to other modes. As can be seen, the control method can make the four-pipe heat pump unit 100 have higher continuity and stability when working, effectively reduce the energy loss in the running process, avoid large water temperature fluctuations, and thus ensure the user's experience.

[0079] It should be noted that in the optional embodiment, the first type of set working mode and the second type of set working mode can be set according to the actual unit function and structure, such as setting the first type of set working mode to only include the refrigeration mode, or setting the second type of set working mode to only include the heating mode, etc. Therefore, the application does not limit this.

[0080] In the control method, the first type of set working mode includes the refrigeration mode and the defrosting mode, and the second type of set working mode includes the heating mode and the heat recovery mode. In the heating mode, the evaporator 25 is in a non-working state, and the compressor 21, the plate heat exchanger 22, the oil separator 23 and the fin heat exchanger 24 form a circulation system. The set condition is that the suction saturation temperature of the compressor 21 is greater than the outlet water temperature of the evaporator 25. In the heat recovery mode, the fin heat exchanger 24 is in a non-working state, and the compressor 21, the plate heat exchanger 22, the oil separator 23 and the evaporator 25 form a circulation system. The set condition is that the suction saturation temperature of the compressor 21 is greater than the ambient temperature.

[0081] In an actual working scenario, when the four-pipe heat pump unit 100 is in the heating mode, the evaporator 25 is in a non-working state. If the system detects that the suction saturation temperature of the compressor 21 is greater than the outlet water temperature of the evaporator 25 at this time, it can be proved that the refrigerant in the circulation system has leaked into the evaporator 25. Therefore, the injection assembly 1 enters the working state according to the set condition, and then the refrigerant in the evaporator 25 is guided back to the circulation system. Similarly, when the four-pipe heat pump unit 100 is in the heat recovery mode, the fin heat exchanger 24 is in a non-working state. If the system detects that the suction saturation temperature of the compressor 21 is greater than the ambient temperature at this time, it can be proved that the refrigerant in the circulation system has leaked into the fin heat exchanger 24. Therefore, the injection assembly 1 also enters the working state according to the set condition, and then the refrigerant in the fin heat exchanger 24 is guided back to the circulation system.

[0082] Therefore, the control method is simple and effective, has high autonomy, and does not need to interrupt the current working mode of the four-pipe heat pump unit 100, effectively improving the continuity and stability of the working process of the four-pipe heat pump unit 100, and thus ensuring the user experience.

[0083] In an optional embodiment, when the four-pipe heat pump unit 100 is in the second type of set working mode and the set operating parameter of the unit module 2 reaches the set condition in S2, the control of the injection assembly 1 from the non-working state to the working state can include:

[0084] S21, in the heating mode, when the corresponding set condition is met, the second electromagnetic valve 16 is closed, and the first electromagnetic valve 15 and the third electromagnetic valve 17 are opened.

[0085] S22, in the heat recovery mode, when the corresponding set condition is met, the third electromagnetic valve 17 is closed, and the first electromagnetic valve 15 and the second electromagnetic valve 16 are opened.

[0086] When the four-pipe heat pump unit 100 triggers the corresponding set conditions, the control method opens the first electromagnetic valve 15 to enable the ejector 14 to access the circulating system. Then according to the specific working condition, the second electromagnetic valve 16 and the third electromagnetic valve 17 are opened correspondingly to access the unit module 2 in the non-working state, and then the leaked refrigerant is guided back to the circulating system. The control method only needs to control the opening and closing of the first electromagnetic valve 15, the second electromagnetic valve 16 and the third electromagnetic valve 17 to achieve the purpose of guiding the refrigerant in the non-working state of the unit module 2 back to the circulating system. It can be seen that the control method has high operation efficiency and stable control process, and effectively saves production and use costs.

[0087] In optional embodiments, when the four-pipe heat pump unit 100 is in the second type of set working mode and the set operating parameters of the unit module 2 reach the set conditions in S2, the control of the ejector assembly 1 from the non-working state to the working state can include:

[0088] S23, in the heating mode, when the corresponding set conditions are met, the second electromagnetic valve 16 and the fourth electromagnetic valve 18 are closed, and the first electromagnetic valve 15, the third electromagnetic valve 17 and the fifth electromagnetic valve 19 are opened.

[0089] S24, in the heat recovery mode, when the corresponding set conditions are met, the third electromagnetic valve 17 and the fifth electromagnetic valve 19 are closed, and the first electromagnetic valve 15, the second electromagnetic valve 16 and the fourth electromagnetic valve 18 are opened.

[0090] In the control method, by controlling the opening and closing of the first electromagnetic valve 15, the second electromagnetic valve 16, the third electromagnetic valve 17, the fourth electromagnetic valve 18 and the fifth electromagnetic valve 19, the leaked refrigerant can be injected from the evaporator 25 to the finned heat exchanger 24, or from the finned heat exchanger 24 to the evaporator 25, thereby achieving the purpose of guiding the refrigerant in the non-working state of the unit module 2 back to the circulating system, effectively expanding the application range and working efficiency of the ejector assembly 1.

[0091] In optional embodiments, when the four-pipe heat pump unit 100 is in the second type of set working mode and the set operating parameters of the unit module 2 reach the set conditions in S2, the control of the ejector assembly 1 from the non-working state to the working state can include:

[0092] S25, control the ejector assembly 1 to be in the working state, and until the operating parameters reach the closing conditions, control the ejector assembly 1 to switch back to the non-working state

[0093] S26, control the ejector assembly 1 to be intermittently switched between the working state and the non-working state, and until the operating parameters reach the closing conditions, control the ejector assembly 1 to switch back to the non-working state.

[0094] In the control method, according to the actual demand of the user and the specific structure and function of the unit, two control modes of S25 and S26 can be selected.

[0095] In S25, after the control of the ejector 14 into the working state, the ejector 14 will work until the detection information sent by the sensor returns to normal (i.e. below the set condition), and the control of the ejector 14 is disconnected and in a non-working state. In S26, referring to the detection information sent by the sensor, the control of the ejector 14 is intermittently switched between the working state and the non-working state until the detection information sent by the sensor returns to normal, and the control of the ejector 14 is disconnected and in a non-working state. Figure 5 It can be seen that after the ejector 14 enters the working state, the control of the ejector 14 is intermittently switched between the working state and the non-working state until the detection information sent by the sensor returns to normal, and the control of the ejector 14 is disconnected and in a non-working state.

[0096] Of course, in some other optional embodiments, the ejector 14 can also be controlled to operate in other working modes, for example: the ejector 14 is controlled to operate at the maximum working efficiency at the start, and the working efficiency is continuously reduced over time until the ejector 14 stops working, and the like. Therefore, the present application does not limit this.

[0097] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of the present application is not limited to the precise structure described in the above embodiments and shown in the drawings; any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A four-pipe heat pump unit, characterized by comprising: The ejector assembly and a plurality of unit modules; wherein the four-pipe heat pump unit has a plurality of working modes, and in each working mode, at least one unit module is in a non-working state, and the remaining unit modules in a working state form a circulation system for circulating refrigerant; The ejector assembly includes a working state and a non-working state; in the non-working state, the ejector assembly is not connected with the circulation system; the ejector assembly is used to switch to the working state under a set condition and is connected with the circulation system to guide the refrigerant from the unit module in the non-working state back to the circulation system. The unit module includes a compressor, a plate heat exchanger, an oil separator, a fin heat exchanger and an evaporator; 2. The four-temperature heat pump unit of claim 1, wherein, The working mode includes a heating mode, and the set condition is that the suction saturation temperature of the compressor is greater than the outlet water temperature of the evaporator; in the heating mode, the evaporator is in a non-working state, and the compressor, the plate heat exchanger, the oil separator and the fin heat exchanger form the circulation system; and / or the working mode includes a heat recovery mode, and the set condition is that the suction saturation temperature of the compressor is greater than the ambient temperature; in the heat recovery mode, the fin heat exchanger is in a non-working state, and the compressor, the plate heat exchanger, the oil separator and the evaporator form the circulation system. The ejector assembly includes a first end, a second end and a third end; the first end is connected with the oil separator in an on-off manner; the second end is connected with the compressor; the third end is connected with the evaporator and the fin heat exchanger in an on-off manner respectively; 3. The four-temperature heat pump unit of claim 2, wherein, In the heating mode, when the corresponding set condition is met, the first end is connected with the oil separator, the third end is connected with the evaporator and disconnected with the fin heat exchanger; And / or, in the heat recovery mode, when the corresponding set condition is met, the first end is connected with the oil separator, the third end is disconnected with the evaporator and connected with the fin heat exchanger. The ejector assembly includes an ejector and first, second and third electromagnetic valves; the first electromagnetic valve is connected between the first end and the oil separator; the second electromagnetic valve is arranged between the third end and the fin heat exchanger; the third electromagnetic valve is connected between the third end and the evaporator; 4. The four-temperature heat pump unit of claim 3, wherein, In the heating mode, when the corresponding set condition is met, the second electromagnetic valve is closed, and the first and third electromagnetic valves are opened; and / or, in the heat recovery mode, when the corresponding set condition is met, the third electromagnetic valve is closed, and the first and second electromagnetic valves are opened. The ejector assembly includes a first end, a second end and a third end; the first end is connected with the oil separator in an on-off manner; the second end is connected with the evaporator and the fin heat exchanger in an on-off manner respectively; the third end is connected with the evaporator and the fin heat exchanger in an on-off manner respectively; 5. The four-temperature heat pump unit of claim 2, wherein, ​ In the heating mode, when the corresponding set conditions are met, the first end is communicated with the oil separator, the second end is disconnected with the evaporator and communicated with the finned heat exchanger, and the third end is communicated with the evaporator and disconnected with the finned heat exchanger; and / or, in the heat recovery mode, when the corresponding set conditions are met, the first end is communicated with the oil separator, the second end is communicated with the evaporator and disconnected with the finned heat exchanger, and the third end is disconnected with the evaporator and communicated with the finned heat exchanger.

6. The four-temperature heat pump unit of claim 5, wherein, The ejector assembly comprises an ejector and first, second, third, fourth and fifth electromagnetic valves; the first electromagnetic valve is connected between the first end and the oil separator; the second electromagnetic valve is arranged and connected between the third end and the finned heat exchanger; the third electromagnetic valve is connected between the second end and the finned heat exchanger; the fourth electromagnetic valve is connected between the second end and the evaporator; and the fifth electromagnetic valve is connected between the third end and the evaporator. In the heating mode, when the corresponding set conditions are met, the second electromagnetic valve and the fourth electromagnetic valve are closed, and the first, third and fifth electromagnetic valves are opened; and / or, in the heat recovery mode, when the corresponding set conditions are met, the third and fifth electromagnetic valves are closed, and the first, second and fourth electromagnetic valves are opened.

7. The four-temperature heat pump unit of claim 6, wherein, The four-pipe heat pump unit further comprises a pre-distributor connected between the finned heat exchanger and the third electromagnetic valve.

8. The four-temperature heat pump unit of claim 2, wherein, The four-pipe heat pump unit further comprises a controller, a sensor, a first four-way reversing valve, a second four-way reversing valve and a defrosting electromagnetic valve; the ejector assembly, the sensor, the first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve are electrically connected with the controller; the first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve are connected between the plate heat exchanger, the oil separator, the finned heat exchanger and the evaporator; the sensor is used to acquire at least one of the suction saturation temperature of the compressor, the outlet water temperature of the evaporator and the ambient temperature; the controller is used to control the energization state of the first four-way reversing valve, the second four-way reversing valve and the defrosting electromagnetic valve to control the working mode of the four-pipe heat pump unit, and to control the ejector assembly to switch between the working state and the non-working state according to the detection information of the sensor.

9. The four-temperature heat pump unit of claim 1, wherein, The ejector assembly comprises an ejector, which comprises: a body, an internal mixing cavity is formed in the body, and a side wall of the body is provided with an inlet end, a discharge end and an introduction end communicated with the mixing cavity; a nozzle, which extends into the mixing cavity from the inlet end and faces the discharge end.

10. The four-temperature heat pump unit of claim 1, wherein, The operating time of the ejector assembly is negatively correlated with the pressure ratio of the four-pipe heat pump unit.

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