Enhanced vapor injection heat pump system and control method thereof

Abstract

The invention provides an enhanced vapor injection heat pump system and a control method thereof. The enhanced vapor injection heat pump system comprises a first intermediate heat exchanger, a second intermediate heat exchanger and a vortex tube. The refrigerant main loop comprises a first heat exchange main road section and a second heat exchange main road section; an inlet of the vortex tube is communicated with the economizer, a cold end outlet of the vortex tube is communicated with an enhanced vapor injection opening of the compressor through a first cold fluid branch or a second cold fluid branch, and a hot end outlet of the vortex tube is communicated with the enhanced vapor injection opening of the compressor through a hot fluid branch. Wherein the first cold fluid branch comprises a first heat exchange auxiliary road section which flows through the first intermediate heat exchanger and exchanges heat with the first heat exchange main road section, and the second cold fluid branch comprises a second heat exchange auxiliary road section which flows through the second intermediate heat exchanger and exchanges heat with the second heat exchange main road section; the energy of the enhanced vapor injection loop can be fully utilized, and the refrigerating and heating capacity of the system is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat pump systems, and more specifically, relates to an ejector-enhanced heat pump system and its control method. Background Art

[0003] Currently, in the case of a large temperature difference between indoor and outdoor environments for air-conditioning products, the refrigeration or heating capacity of the unit will decline to varying degrees. To alleviate this problem, technical means such as hot gas bypass, refrigerant heat storage, and ejector enhancement are commonly used in the industry to improve refrigeration or heating performance. Taking the ejector-enhanced heat pump system as an example, this system mainly consists of an ejector-enhanced compressor, an indoor heat exchanger, an outdoor heat exchanger, a four-way valve, an economizer, and pipelines connecting various components. However, the existing ejector-enhanced heat pump systems still have limitations in enhancing refrigeration and heating capabilities and are difficult to adapt to a wider range of indoor and outdoor temperature difference environments. Summary of the Invention

[0004] The object of the present invention is to propose an ejector-enhanced heat pump system and its control method, aiming to improve refrigeration and heating performance in the case of a large temperature difference between indoor and outdoor environments.

[0005] To achieve the above object, the technical solution adopted by the present invention is: The present invention proposes an ejector-enhanced heat pump system, including a compressor, a four-way valve, an indoor heat exchanger, an economizer, and an outdoor heat exchanger connected to form a main refrigerant circuit, and further including a first intermediate heat exchanger, a second intermediate heat exchanger, and a vortex tube; The main refrigerant circuit includes a first main heat exchange section located between the indoor heat exchanger and the economizer and flowing through the first intermediate heat exchanger, and a second main heat exchange section located between the economizer and the outdoor heat exchanger and flowing through the second intermediate heat exchanger; The inlet of the vortex tube is connected to the economizer, the cold end outlet of the vortex tube is connected to the ejector-enhanced port of the compressor through a first cold fluid branch or a second cold fluid branch, and the hot end outlet of the vortex tube is connected to the ejector-enhanced port of the compressor through a hot fluid branch; Wherein, the first cold fluid branch includes a first auxiliary heat exchange section flowing through the first intermediate heat exchanger and performing heat exchange with the first main heat exchange section, and the second cold fluid branch includes a second auxiliary heat exchange section flowing through the second intermediate heat exchanger and performing heat exchange with the second main heat exchange section.

[0006] Further, it further includes a gas-liquid separator and a third intermediate heat exchanger. The main refrigerant circuit further includes a third main heat exchange section located between the gas-liquid separator and the suction port of the compressor and flowing through the third intermediate heat exchanger, and the hot fluid branch includes a third auxiliary heat exchange section flowing through the third intermediate heat exchanger and performing heat exchange with the third main heat exchange section.

[0007] Further, after the first cold fluid branch or the second cold fluid branch merges with the hot fluid branch to form a merging branch, the merging branch is communicated with the jet enthalpy injection port of the compressor.

[0008] Further, a check valve is provided on the merging branch.

[0009] Further, control valves for controlling their own on-off states are provided on the first cold fluid branch, the second cold fluid branch, and the hot fluid branch.

[0010] Further, flow regulating valves are respectively provided at the cold end outlet and the hot end outlet of the vortex tube.

[0011] Further, the first intermediate heat exchanger, the second intermediate heat exchanger, and the third intermediate heat exchanger all adopt plate heat exchangers or shell-and-tube heat exchangers.

[0012] Further, the first inlet of the economizer is connected between the first intermediate heat exchanger and the second intermediate heat exchanger through a main branch, the first outlet of the economizer is connected between the first intermediate heat exchanger and the second intermediate heat exchanger through a first shunt branch, the first outlet of the economizer is communicated with the second inlet of the economizer through a second shunt branch, and the second outlet of the economizer is communicated with the inlet of the vortex tube through an auxiliary branch.

[0013] Further, a main throttle valve is provided on the first shunt branch, and an auxiliary throttle valve is provided on the second shunt branch.

[0014] The present invention also proposes a control method for a jet enthalpy injection heat pump system. The jet enthalpy injection heat pump system adopts the jet enthalpy injection heat pump system as described above. The control method for the jet enthalpy injection heat pump system includes: Obtain the working mode of the jet enthalpy injection heat pump system, where the working mode includes a refrigeration mode and a heating mode; Control the on-off states of the first cold fluid branch, the second cold fluid branch, and the hot fluid branch according to the working mode; Adjust the flow rate at the hot end outlet of the vortex tube according to the comparison result between the measured suction temperature and the target suction temperature of the compressor.

[0015] Compared with the prior art, the beneficial effects of the jet enthalpy injection heat pump system and its control method proposed by the present invention are as follows: The jet enthalpy injection heat pump system proposed by the present invention makes full use of the energy of the jet enthalpy injection loop through the vortex effect of the vortex tube, and can effectively increase the outlet subcooling degree of the condenser. This not only enhances the refrigeration and heating capabilities of the system, but also improves the operating energy efficiency ratio, enabling it to better adapt to a wider range of indoor and outdoor temperature difference conditions. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 Principle of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 1 ; Figure 2 Principle of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 2 ; Figure 3 Principle of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 3 ; Figure 4 Principle of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 4 ; Figure 5 Schematic diagram of the economizer proposed in the preferred embodiment of the present invention; Figure 6 Schematic diagram of the vortex tube proposed in the preferred embodiment of the present invention; Figure 7 Schematic diagram of the four-way valve proposed in the preferred embodiment of the present invention; Figure 8 Schematic diagram of the control method flow of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 1 ; Figure 9 Schematic diagram of the control method flow of the jet enthalpy-increasing heat pump system proposed in the preferred embodiment of the present invention Figure 2 ; Among them, the main reference signs in the drawings are as follows: 1, compressor; 3, indoor heat exchanger; 4, first intermediate heat exchanger; 9, second intermediate heat exchanger; 12, third intermediate heat exchanger; 7, main throttle valve; 8, auxiliary throttle valve; 10, outdoor heat exchanger; 11, gas-liquid separator; 13, first control valve; 14, second control valve; 15, third control valve; 16, first check valve; 17, second check valve; 18, third check valve; 19, fourth check valve; 20, fifth check valve; 2, four-way valve; 21, first interface; 22, second interface; 23, third interface; 24, fourth interface; 5. Economizer; 51. First inlet; 52. First outlet; 53. Second inlet; 54. Second outlet; 6. Vortex tube; 61. Inlet; 62. Cold end outlet; 63. Hot end outlet; 101. First cold fluid branch; 102. Second cold fluid branch; 103. Hot fluid branch; 104. Main branch; 105. First shunt branch; 106. Second shunt branch; 107. Auxiliary branch. Detailed implementation manners

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Currently, when the temperature difference between indoor and outdoor of air-conditioning products is relatively large, their refrigeration or heating capacity will decrease to varying degrees. To solve this problem, the industry usually adopts technical means such as hot gas bypass, refrigerant heat storage, and jet enthalpy increase to enhance the refrigeration or heating performance. Taking the jet enthalpy increase heat pump system as an example, this system mainly consists of a jet enthalpy increase compressor, an indoor heat exchanger, an outdoor heat exchanger, a four-way valve, an economizer, and pipelines connecting various components. However, the existing jet enthalpy increase heat pump system still has certain limitations in improving the refrigeration and heating performance, and it is difficult to fully adapt to a wider range of indoor and outdoor temperature difference environments. Based on this, the present invention proposes a new type of jet enthalpy increase heat pump system and its control method, aiming to further improve the refrigeration and heating performance under larger indoor and outdoor temperature differences.

[0020] Please refer to Figures 1 to 4 、 Figure 6 The jet enthalpy increase heat pump system proposed in the preferred embodiment of the present invention mainly consists of the following components connected to form a refrigerant main circuit: compressor 1, four-way valve 2, indoor heat exchanger 3, economizer 5, and outdoor heat exchanger 10. In addition, the jet enthalpy increase heat pump system also includes a first intermediate heat exchanger 4, a second intermediate heat exchanger 9, and a vortex tube 6.

[0021] The refrigerant main circuit includes a first main heat exchange section located between the indoor heat exchanger 3 and the economizer 5 and flowing through the first intermediate heat exchanger 4, and a second main heat exchange section located between the economizer 5 and the outdoor heat exchanger 10 and flowing through the second intermediate heat exchanger 9; The inlet 61 of the vortex tube 6 is communicated with the economizer 5, the cold end outlet 62 of the vortex tube 6 is communicated with the jet enthalpy increase port of the compressor 1 through the first cold fluid branch 101 or the second cold fluid branch 102, and the hot end outlet 63 of the vortex tube 6 is communicated with the jet enthalpy increase port of the compressor 1 through the hot fluid branch 103; Among them, the first cold fluid branch 101 includes a first heat exchange auxiliary section that flows through the first intermediate heat exchanger 4 and exchanges heat with the first heat exchange main section, and the second cold fluid branch 102 includes a second heat exchange auxiliary section that flows through the second intermediate heat exchanger 9 and exchanges heat with the second heat exchange main section.

[0022] In this jet-increased enthalpy heat pump system, the vortex effect of the vortex tube 6 is utilized to separate the fluid from the economizer 5 into two cold and hot fluids. The cold fluid is discharged from the cold end outlet 62 of the vortex tube 6, while the hot fluid is discharged from the hot end outlet 63.

[0023] When the jet-increased enthalpy heat pump system is in the heating mode, the cold fluid discharged from the cold end of the vortex tube 6 enters the compressor 1 after flowing through the first intermediate heat exchanger 4 via the first cold fluid branch 101. During this process, the first heat exchange auxiliary section of the first cold fluid branch 101 exchanges heat with the first heat exchange main section of the refrigerant main circuit in the first intermediate heat exchanger 4. This process can increase the subcooling degree of the fluid at the outlet of the indoor heat exchanger 3, thereby improving the heating energy efficiency of the entire system.

[0024] When the jet-increased enthalpy heat pump system is in the cooling mode, the cold fluid discharged from the cold end of the vortex tube 6 enters the compressor 1 after flowing through the second intermediate heat exchanger 9 via the second cold fluid branch 102. During this process, the second heat exchange auxiliary section of the second cold fluid branch 102 exchanges heat with the second heat exchange main section of the refrigerant main circuit in the second intermediate heat exchanger 9. This process can increase the subcooling degree of the fluid at the outlet of the outdoor heat exchanger 10, thereby improving the cooling energy efficiency of the entire system.

[0025] It should be clear that when the jet-increased enthalpy heat pump system is in the heating mode, the indoor heat exchanger 3 operates as a condenser, while the outdoor heat exchanger 10 operates as an evaporator. On the contrary, when the jet-increased enthalpy heat pump system is in the cooling mode, the indoor heat exchanger 3 operates as an evaporator, while the outdoor heat exchanger 10 operates as a condenser.

[0026] In addition, regardless of whether the jet-increased enthalpy heat pump system is in the heating mode or the cooling mode, the hot fluid discharged from the hot end of the vortex tube 6 enters the compressor 1 through the hot fluid branch 103. In the heating mode, this hot fluid branch 103 and the aforementioned first cold fluid branch 101 form a jet-increased enthalpy circuit; while in the cooling mode, this hot fluid branch 103 and the aforementioned second cold fluid branch 102 form a jet-increased enthalpy circuit.

[0027] Therefore, the jet-increased enthalpy heat pump system proposed by the present invention can make full use of the energy of the jet-increased enthalpy circuit, effectively increasing the subcooling degree at the outlet of the condenser. This not only enhances the cooling and heating capabilities of the system but also improves the operating energy efficiency ratio, enabling it to better adapt to a wider range of indoor and outdoor temperature differences. Under high-temperature cooling and low-temperature heating conditions, the operating effect of the system has been significantly improved.

[0028] In a preferred embodiment of the present invention, as Figure 2 shown, the jet-injected enthalpy-increasing heat pump system further includes a gas-liquid separator 11 and a third intermediate heat exchanger 12. The main refrigerant circuit further includes a third main heat exchange section located between the gas-liquid separator 11 and the suction port of the compressor 1 and flowing through the third intermediate heat exchanger 12. The hot fluid branch 103 includes a third auxiliary heat exchange section flowing through the third intermediate heat exchanger 12 and performing heat exchange with the third main heat exchange section. In addition, a suction temperature sensor is provided at the suction port of the compressor 1, and the temperature of the suction port can be detected.

[0029] In this jet-injected enthalpy-increasing heat pump system, the hot fluid discharged from the hot end of the vortex tube 6 enters the compressor 1 after flowing through the third intermediate heat exchanger 12 via the hot fluid branch 103. During this process, the third auxiliary heat exchange section of the hot fluid branch 103 exchanges heat with the third main heat exchange section of the main refrigerant circuit in the third intermediate heat exchanger 12. This process can effectively increase the superheat degree of the fluid at the outlet of the gas-liquid separator 11, thereby reducing the risk of liquid carry-over at the suction of the compressor 1.

[0030] In a preferred embodiment of the present invention, as Figure 2 shown, the first cold fluid branch 101 or the second cold fluid branch 102 merges with the hot fluid branch 103 to form a merged branch and is then connected to the jet-injected enthalpy port of the compressor 1.

[0031] In this jet-injected enthalpy-increasing heat pump system, when the system is in the heating mode, the first cold fluid branch 101 will flow through the first intermediate heat exchanger 4, while the hot fluid branch 103 will flow through the third intermediate heat exchanger 12. At this time, the fluids of the first cold fluid branch 101 and the hot fluid branch 103 are mixed and then enter the compressor 1. This process can effectively reduce the risk of liquid carry-over in the jet-injected enthalpy circuit of the compressor 1. When the system switches to the cooling mode, the second cold fluid branch 102 will flow through the second intermediate heat exchanger 9, while the hot fluid branch 103 will flow through the third intermediate heat exchanger 12. At this time, the fluids of the second cold fluid branch 102 and the hot fluid branch 103 are mixed and then enter the compressor 1, which can also effectively reduce the risk of liquid carry-over in the jet-injected enthalpy circuit of the compressor 1.

[0032] In a preferred embodiment of the present invention, as Figure 2 shown, a check valve, namely the first check valve 16, is provided on the merged branch.

[0033] The check valve is provided to ensure that the fluid can only flow in one direction, thereby preventing system instability or damage caused by backflow. When the jet-injected enthalpy heat pump system operates in the heating or cooling mode, the check valve can ensure that the fluid on the merged branch smoothly enters the compressor 1, avoiding interfering with the normal operation of the system due to backflow. This design further improves the stability and reliability of the jet-injected enthalpy heat pump system and optimizes its overall performance.

[0034] In a preferred embodiment of the present invention, as Figure 2 shown, control valves for controlling their own on-off states are provided on the first cold fluid branch 101, the second cold fluid branch 102, and the hot fluid branch 103. Specifically, a first control valve 13 is provided on the first cold fluid branch 101, a second control valve 14 is provided on the second cold fluid branch 102, and a third control valve 15 is provided on the hot fluid branch 103. The first control valve 13, the second control valve 14, and the third control valve 15 can all be selected as solenoid valves.

[0035] The setting of these control valves enables the system to flexibly adjust the on-off states of each branch according to actual needs, thereby achieving more precise control of the jet-enhanced enthalpy heat pump system. In the heating mode, the first control valve 13 and the third control valve 15 are opened to allow the fluids in the first cold fluid branch 101 and the hot fluid branch 103 to enter the compressor 1, forming a jet-enhanced enthalpy loop. During this process, the second control valve 14 remains closed to prevent the fluid in the second cold fluid branch 102 from interfering with the heating effect. In the cooling mode, the second control valve 14 and the third control valve 15 are opened to allow the fluids in the second cold fluid branch 102 and the hot fluid branch 103 to enter the compressor 1, forming a jet-enhanced enthalpy loop. During this process, the first control valve 13 remains closed to avoid the fluid in the first cold fluid branch 101 from interfering with the cooling effect.

[0036] In a preferred embodiment of the present invention, flow regulating valves are respectively provided at the cold end outlet 62 and the hot end outlet 63 of the vortex tube 6. The regulating valve can be selected as a stepless proportional regulating valve to achieve precise control of the fluid flow rate at each outlet.

[0037] The setting of these flow regulating valves further improves the flexibility and control accuracy of the system. By adjusting the fluid flow rates discharged from the cold end and the hot end of the vortex tube 6, the system can more precisely control the ratio of the cold fluid to the hot fluid flowing to the jet-enhanced enthalpy port of the compressor 1, thereby effectively reducing the risk of liquid carry-over at the compressor 1 suction and in the jet-enhanced enthalpy loop.

[0038] In a preferred embodiment of the present invention, the first intermediate heat exchanger 4, the second intermediate heat exchanger 9, and the third intermediate heat exchanger 12 all adopt plate heat exchangers or shell-and-tube heat exchangers.

[0039] Both plate heat exchangers and shell-and-tube heat exchangers possess excellent heat exchange performance and can efficiently and rapidly achieve heat transfer between two fluids. Although they are similar in terms of high-efficiency heat exchange and compact design, plate heat exchangers are more prominent in terms of heat transfer efficiency, structural flexibility, and lightweight, while shell-and-tube heat exchangers have obvious advantages in terms of pressure resistance, seismic performance, and medium adaptability. In practical applications, the selection of which heat exchanger to use requires comprehensive consideration of specific operating conditions, such as the properties of the fluids, space limitations, and maintenance requirements, etc., and a comprehensive trade-off should be made.

[0040] In addition, the indoor heat exchanger 3 can be a finned-tube heat exchanger, a plate heat exchanger, a shell-and-tube heat exchanger, etc., the outdoor heat exchanger 10 can be a finned-tube heat exchanger, etc., and the economizer 5 can be a plate heat exchanger or a shell-and-tube heat exchanger, etc.

[0041] In a preferred embodiment of the present invention, as Figure 2 , Figure 5 , Figure 6 shown, the first inlet 51 of the economizer 5 is connected between the first intermediate heat exchanger 4 and the second intermediate heat exchanger 9 through the main branch 104, the first outlet 52 of the economizer 5 is connected between the first intermediate heat exchanger 4 and the second intermediate heat exchanger 9 through the first shunt branch 105, the first outlet 52 of the economizer 5 communicates with the second inlet 53 of the economizer 5 through the second shunt branch 106, and the second outlet 54 of the economizer 5 communicates with the inlet 61 of the vortex tube 6 through the auxiliary branch 107.

[0042] In this jet-increased enthalpy heat pump system, when the system is in the heating mode, the refrigerant (also known as the refrigerant) flowing out of the indoor heat exchanger 3 first flows through the first intermediate heat exchanger 4 and then enters the first inlet 51 of the economizer 5. The refrigerant flowing out of the first outlet 52 of the economizer 5 is divided into two paths: one path flows through the first shunt branch 105 to the second intermediate heat exchanger 9, and the other path flows through the second shunt branch 106 into the second inlet 53 of the economizer 5, then flows out through the second outlet 54, and enters the vortex tube 6 through the auxiliary branch 107. When the system is in the cooling mode, the refrigerant flowing out of the outdoor heat exchanger 10 first flows through the second intermediate heat exchanger 9 and then enters the first inlet 51 of the economizer 5. The refrigerant flowing out of the first outlet 52 of the economizer 5 is also divided into two paths: one path flows through the first shunt branch 105 to the first intermediate heat exchanger 4, and the other path flows through the second shunt branch 106 into the second inlet 53 of the economizer 5, then flows out through the second outlet 54, and enters the vortex tube 6 through the auxiliary branch 107. The design of this economizer 5 can ensure an efficient and stable connection between the main refrigerant circuit and the vortex tube 6, thereby ensuring the operating efficiency and reliability of the entire system. Through the vortex effect of the vortex tube 6, the energy of the jet-increased enthalpy circuit can be effectively utilized, avoiding energy waste, and thus significantly improving the energy efficiency of the whole machine.

[0043] In a preferred embodiment of the present invention, as Figure 2 shown, a main throttle valve 7 is provided on the first shunt branch 105, and an auxiliary throttle valve 8 is provided on the second shunt branch 106. Both the main throttle valve 7 and the auxiliary throttle valve 8 can adopt electronic expansion valves.

[0044] The coordinated setting of the main throttle valve 7 and the auxiliary throttle valve 8 enables the system to flexibly adjust the refrigerant flow according to the operating conditions, thereby further optimizing the overall performance. The main throttle valve 7 is responsible for regulating and controlling the refrigerant flow from the economizer 5 to the first intermediate heat exchanger 4 or the second intermediate heat exchanger 9 to ensure that the intermediate heat exchanger can efficiently perform heat exchange. At the same time, the auxiliary throttle valve 8 is responsible for regulating and controlling the refrigerant flow returning to the economizer 5 to maintain the stability of the internal pressure of the economizer 5. Through the coordinated action of the main throttle valve 7 and the auxiliary throttle valve 8, the reliability and adaptability of the system are enhanced, enabling it to maintain a good operating state under various different working conditions.

[0045] Based on the detailed introduction of the jet-injection heat pump system above, the control method thereof will be briefly described next.

[0046] Please refer to Figure 8 together, the control method of the jet-injection heat pump system includes the following steps: Obtain the working mode of the jet-injection heat pump system, where the working mode includes a refrigeration mode and a heating mode; Control the on-off states of the first cold fluid branch, the second cold fluid branch, and the hot fluid branch according to the working mode; Adjust the flow rate at the hot end outlet of the vortex tube according to the comparison result between the measured suction temperature of the compressor and the target suction temperature.

[0047] As Figure 9 shown, in practical applications, after the jet-injection heat pump system is started, it will first identify the working mode selected by the user. If the heating mode is selected, the first control valve and the third control valve are opened, while the second control valve is closed; if the refrigeration mode is selected, the second control valve and the third control valve are opened, while the first control valve is closed. The system monitors the suction temperature of the compressor in real time, compares it with the preset target value, and adjusts the opening degree of the flow regulating valve at the hot end outlet of the vortex tube according to the comparison result, thereby achieving precise control of the flow rate at the hot end outlet of the vortex tube. The specific adjustment strategy is as follows: when the measured suction temperature > the target suction temperature + deviation value, the flow rate at the hot end outlet of the vortex tube is reduced; when the measured suction temperature < the target suction temperature - deviation value, the flow rate at the hot end outlet of the vortex tube is increased; when the target suction temperature - deviation value < the measured suction temperature and the measured suction temperature < the target suction temperature + deviation value, the flow rate at the hot end outlet of the vortex tube remains unchanged.

[0048] The present invention significantly improves the refrigeration and heating performance of the system by introducing a vortex tube into the jet-increased enthalpy heat pump system. The system dynamically adjusts the flow rate at the hot end outlet of the vortex tube according to the difference between the measured suction temperature and the target suction temperature of the compressor, thereby more effectively reducing the risk of liquid carry-over at the compressor suction. This improvement not only effectively protects the compressor but also significantly enhances the operational reliability of the system.

[0049] To more comprehensively understand the present invention, the structure of the jet-increased enthalpy heat pump system will be described in detail below in conjunction with the accompanying drawings.

[0050] As Figure 2 , Figures 5 to 7 shown, the jet-increased enthalpy heat pump system mainly consists of the following components: compressor 1, four-way valve 2, indoor heat exchanger 3, intermediate heat exchanger, economizer 5, vortex tube 6, main throttle valve 7, auxiliary throttle valve 8, outdoor heat exchanger 10, gas-liquid separator 11, first control valve 13, second control valve 14, third control valve 15, first check valve 16, second check valve 17, third check valve 18, fourth check valve 19, and fifth check valve 20. Among them, the economizer 5 has a first inlet 51, a first outlet 52, a second inlet 53, and a second outlet 54, the vortex tube 6 has an inlet 61, a cold end outlet 62, and a hot end outlet 63, and the four-way valve 2 has a first interface 21, a second interface 22, a third interface 23, and a fourth interface 24.

[0051] As Figure 2 , Figure 3 shown, when the jet-increased enthalpy heat pump system is in the heating mode: First, the high-temperature and high-pressure gaseous refrigerant enters the first interface 21 of the four-way valve 2 after passing through the compressor 1, flows out from the second interface 22, and then enters the indoor heat exchanger 3; Then, after flowing out from the indoor heat exchanger 3, it flows through the first intermediate heat exchanger 4, enters the first inlet 51 of the economizer 5 through the second check valve 17, and the refrigerant flowing out from the first outlet 52 is divided into two parts; One part of the refrigerant passes through the main throttle valve 7, flows through the fifth check valve 20 and the second intermediate heat exchanger 9, then enters the outdoor heat exchanger 10, flows out from the outdoor heat exchanger 10, enters the fourth interface 24 of the four-way valve 2, flows out from the third interface 23, and enters the suction port of the compressor 1 after passing through the gas-liquid separator 11 and the third intermediate heat exchanger 12; The other part of the refrigerant passes through the auxiliary throttle valve 8, flows into the second inlet 53 of the economizer 5, flows out from the second outlet 54, enters the inlet 61 of the vortex tube 6, and the fluid entering the vortex tube 6 is divided into two parts; the cold fluid flows out from the cold end outlet 62, passes through the first control valve 13, and enters the first intermediate heat exchanger 4; the hot fluid flows out from the hot end outlet 63, passes through the third control valve 15, and enters the third intermediate heat exchanger 12; Finally, the refrigerant after heat exchange in the first intermediate heat exchanger 4 and the third intermediate heat exchanger 12 is mixed and then enters the jet enthalpy injection port of the compressor 1 through the first one-way valve 16, completing the auxiliary circuit compression cycle.

[0052] As Figure 2 , Figure 4 shown, when the jet enthalpy injection heat pump system is in the refrigeration mode: First, the high-temperature and high-pressure gaseous refrigerant enters the first interface 21 of the four-way valve 2 after passing through the compressor 1, flows out from the fourth interface 24 and then enters the outdoor heat exchanger 10. Second, after flowing out from the indoor heat exchanger 3, it flows through the second intermediate heat exchanger 9, passes through the fourth one-way valve 19 and enters the first inlet 51 of the economizer 5. The refrigerant after flowing out from the first outlet 52 is divided into two parts. One part of the refrigerant passes through the main throttle valve 7, flows through the third one-way valve 18 and the first intermediate heat exchanger 4 and then enters the indoor heat exchanger 3. After flowing out from the indoor heat exchanger 3, it enters the second interface 22 of the four-way valve 2, flows out from the third interface 23, passes through the gas-liquid separator 11 and the third intermediate heat exchanger 12 and then enters the suction port of the compressor 1, completing the main circuit compression cycle.

[0053] The other part of the refrigerant passes through the auxiliary throttle valve 8, flows into the fourth interface 24 of the economizer 5, flows out from the third interface 23 and then enters the inlet 61 of the vortex tube 6. The fluid entering the vortex tube 6 is divided into two parts. The cold fluid flows out from the cold end outlet 62, passes through the second control valve 14 and enters the second intermediate heat exchanger 9. The hot fluid flows out from the hot end outlet 63, passes through the third control valve 15 and enters the third intermediate heat exchanger 12. Finally, the refrigerant after heat exchange in the second intermediate heat exchanger 9 and the third intermediate heat exchanger 12 is mixed and then enters the jet enthalpy injection port of the compressor 1 through the first one-way valve 16, completing the auxiliary circuit compression cycle.

[0054] The present invention proposes a jet enthalpy injection heat pump system with a vortex tube, which belongs to a quasi-two-stage compression system of an intermediate gas-injected compressor. Through the vortex effect generated by the vortex tube, the system can optimize the energy utilization efficiency of the jet enthalpy injection circuit to the greatest extent. By efficiently utilizing the energy of the jet enthalpy injection circuit, the system not only improves the subcooling degree at the condenser outlet and the superheat degree at the compressor suction port, but also effectively reduces the risks of liquid carry-over at the compressor suction and in the enthalpy injection circuit, thereby significantly enhancing the refrigeration and heating performance of the system, improving the operating energy efficiency ratio, and ensuring the stable operation of the system under large indoor and outdoor temperature differences.

[0055] In the description of the present invention, it should be understood that unless otherwise clearly specified and defined, when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0056] In addition, the orientation or positional relationship indicated by terms such as "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0057] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0058] In addition, the terms "mounted", "connected", and "joined" 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 or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A jet-increased enthalpy heat pump system, comprising a compressor, a four-way valve, an indoor heat exchanger, an economizer, and an outdoor heat exchanger that are connected to form a main refrigerant circuit, characterized in that, It also includes a first intermediate heat exchanger, a second intermediate heat exchanger, and a vortex tube; The main refrigerant circuit includes a first main heat exchange section located between the indoor heat exchanger and the economizer and flowing through the first intermediate heat exchanger, and a second main heat exchange section located between the economizer and the outdoor heat exchanger and flowing through the second intermediate heat exchanger; The inlet of the vortex tube is communicated with the economizer, the cold end outlet of the vortex tube is communicated with the jet enthalpy increase port of the compressor through a first cold fluid branch or a second cold fluid branch, and the hot end outlet of the vortex tube is communicated with the jet enthalpy increase port of the compressor through a hot fluid branch; Wherein, the first cold fluid branch includes a first heat exchange auxiliary section flowing through the first intermediate heat exchanger and performing heat exchange with the first main heat exchange section, and the second cold fluid branch includes a second heat exchange auxiliary section flowing through the second intermediate heat exchanger and performing heat exchange with the second main heat exchange section.

2. The jet-increased enthalpy heat pump system according to claim 1, wherein It also includes a gas-liquid separator and a third intermediate heat exchanger. The main refrigerant circuit also includes a third main heat exchange section located between the gas-liquid separator and the suction port of the compressor and flowing through the third intermediate heat exchanger. The hot fluid branch includes a third heat exchange auxiliary section flowing through the third intermediate heat exchanger and performing heat exchange with the third main heat exchange section.

3. The jet enthalpy increase heat pump system according to claim 2, wherein, The first cold fluid branch or the second cold fluid branch and the hot fluid branch converge to form a converging branch and then are communicated with the jet enthalpy increase port of the compressor.

4. The jet-injected heat pump system according to claim 3, wherein A check valve is arranged on the converging branch.

5. The jet-increased enthalpy heat pump system according to claim 1, characterized in that Control valves for controlling their own on-off states are arranged on the first cold fluid branch, the second cold fluid branch, and the hot fluid branch.

6. The jet enthalpy boost heat pump system according to claim 1, wherein Flow regulating valves are respectively arranged at the cold end outlet and the hot end outlet of the vortex tube.

7. The jet-increased enthalpy heat pump system according to claim 2, wherein The first intermediate heat exchanger, the second intermediate heat exchanger, and the third intermediate heat exchanger all adopt plate heat exchangers or shell-and-tube heat exchangers.

8. The jet-increased enthalpy heat pump system according to claim 1, wherein The first inlet of the economizer is connected between the first intermediate heat exchanger and the second intermediate heat exchanger through a main branch, the first outlet of the economizer is connected between the first intermediate heat exchanger and the second intermediate heat exchanger through a first shunt branch, the first outlet of the economizer is communicated with the second inlet of the economizer through a second shunt branch, and the second outlet of the economizer is communicated with the inlet of the vortex tube through an auxiliary branch.

9. The jet enthalpy-increasing heat pump system according to claim 8, wherein, A main throttle valve is arranged on the first shunt branch, and an auxiliary throttle valve is arranged on the second shunt branch.

10. A control method for a jet enthalpy-increasing heat pump system, characterized in that, The jet enthalpy increase heat pump system adopts the jet enthalpy increase heat pump system according to any one of claims 2-9. The control method of the jet enthalpy increase heat pump system includes: Obtaining the working mode of the jet enthalpy increase heat pump system, wherein the working mode includes a refrigeration mode and a heating mode; Controlling the on-off states of the first cold fluid branch, the second cold fluid branch, and the hot fluid branch according to the working mode; Adjusting the flow rate of the hot end outlet of the vortex tube according to the comparison result between the measured suction temperature of the compressor and the target suction temperature.

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