A dual cycle refrigeration system and air conditioner with a compressor and a fluorine pump

Abstract

The application discloses a double-cycle refrigerating system of a compressor and a fluorine pump and an air conditioner, and aims at solving the technical problem that the inlet cavitation margin of the fluorine pump in the existing double-cycle refrigerating system is small and cavitation and flow break often occur. The application comprises a water circulation assembly and a compressor, a first condenser, a second condenser, a fluorine pump, a throttling element and an evaporator which are sequentially connected to form a closed refrigerant loop; the water circulation assembly is used for providing cooling water to exchange heat with the refrigerant in the second condenser. In the embodiment, the refrigerant outlet end of the first condenser is connected with the second condenser, the first condenser plays a main heat exchange role of the refrigerant, the water circulation assembly provides cooling water to exchange heat with the refrigerant in the second condenser after the refrigerant enters the second condenser from the first condenser, thereby realizing secondary heat exchange of the refrigerant, and the second condenser also plays a liquid storage role, effectively improving the supercooling degree at the inlet of the fluorine pump, thereby solving the technical problem that cavitation and flow break often occur at the inlet of the fluorine pump.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more particularly to a dual-cycle refrigeration system and air conditioner with a compressor and a refrigerant pump. Background Technology

[0002] To reduce the energy consumption of air conditioning systems, refrigerant pump energy-saving technology is a new technology that has emerged in recent years. The core of refrigerant pump energy-saving technology is to use the power of a pump to circulate the refrigerant in the closed pipeline. Because the electrical power of the refrigerant pump is often much smaller than that of the compressor, the refrigerant pump system has high energy efficiency.

[0003] Because the compressor cycle and the refrigerant pump cycle require different amounts of refrigerant, existing technologies often include a receiver tank between the condenser and the refrigerant pump to accommodate the different refrigerant requirements of the two cycles. Increasing the liquid level in the receiver tank increases subcooling to prevent cavitation and flow interruption caused by low net positive suction head (NPSH) at the refrigerant pump inlet. However, to achieve the required subcooling, the receiver tank needs to be designed with a relative height lower than the condenser and higher than the refrigerant pump inlet. This method introduces significant challenges in piping design and easily leads to difficulties in pipe insulation and resistance losses. This can cause refrigerant vaporization within the piping, resulting in low NPSH at the refrigerant pump inlet, cavitation, and flow interruption, severely impacting the safe operation of the refrigerant pump.

[0004] Therefore, finding a technical solution that can solve the above-mentioned technical problems has become an important research topic for those skilled in the art. Summary of the Invention

[0005] This invention discloses a dual-cycle refrigeration system and air conditioner with a compressor and a refrigerant pump, which solves the technical problems of small net positive suction head (NPSH) at the inlet of the refrigerant pump in existing dual-cycle refrigeration systems, which often result in cavitation and flow interruption.

[0006] This invention provides a dual-cycle refrigeration system of a compressor and a refrigerant pump, including a water circulation component and a compressor, a first condenser, a second condenser, a refrigerant pump, a throttling element, and an evaporator connected in sequence to form a closed refrigerant circuit;

[0007] The water circulation assembly is used to provide cooling water for heat exchange with the refrigerant in the second condenser.

[0008] Optionally, the second condenser is a coaxial heat exchanger or a shell-and-tube heat exchanger.

[0009] Optionally, the water circulation assembly includes a first water pump and a first water storage tank. The inlet port of the first water pump is connected to the first water storage tank, the outlet port of the first water pump is connected to the cooling water inlet of the second condenser, and the cooling water outlet of the second condenser is located above the first water storage tank.

[0010] Optionally, it also includes a first precooling device, the cooling water outlet of the second condenser is connected to the first precooling device, the first condenser is equipped with a condensing fan, the first precooling device is located on the air inlet side of the first condenser, and the first water storage tank is located below the first precooling device.

[0011] Optionally, the second condenser is a condenser coil.

[0012] Optionally, the water circulation assembly includes a second water pump, a second water storage tank, and a spray device;

[0013] The inlet port of the second water pump is connected to the second water storage tank, the outlet port of the second water pump is connected to the spray device, the second condenser is located below the spray device, and the second water storage tank is located below the spray device.

[0014] Optionally, a second precooling device may also be included;

[0015] The first condenser is equipped with a condensing fan, and the second precooling device is located on the air inlet side of the first condenser, and the second precooling device is located below the spray device;

[0016] The second condenser is located inside the second water storage tank, or the second condenser is located between the spray device and the second precooling device, or the second condenser is located between the second precooling device and the second water storage tank.

[0017] Optionally, a first check valve is provided between the compressor and the first condenser.

[0018] Optionally, it may also include a first bypass line and a second bypass line;

[0019] One end of the first bypass pipe is connected to the pipe between the first one-way valve and the first condenser, and the other end of the first bypass pipe is connected to the pipe between the compressor and the evaporator. A second one-way valve is connected to the first bypass pipe.

[0020] One end of the second bypass line is connected to the pipeline between the second condenser and the refrigerant pump, and the other end of the second bypass line is connected to the pipeline between the refrigerant pump and the throttling element. A third check valve is connected to the second bypass line.

[0021] This invention provides an air conditioner, including an electronic control device and a dual-cycle refrigeration system consisting of the aforementioned compressor and refrigerant pump.

[0022] As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

[0023] In this embodiment, the liquid storage tank design in the existing dual-cycle system is eliminated. A second condenser is connected to the refrigerant outlet of the first condenser. The first condenser plays the main role in heat exchange of the refrigerant. After the refrigerant enters the second condenser from the first condenser, the water circulation component provides cooling water to exchange heat with the refrigerant in the second condenser, thereby realizing secondary heat exchange of the refrigerant. In addition, the second condenser also plays the role of liquid storage, effectively improving the subcooling at the inlet of the refrigerant pump. This solves the technical problems of cavitation and flow interruption that often occur at the inlet of the refrigerant pump, improves the operating efficiency and service life of the refrigerant pump, and ensures the energy-saving refrigeration effect of the dual-cycle refrigeration system of the compressor and refrigerant pump. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a dual-cycle refrigeration system with a compressor and a refrigerant pump.

[0026] Figure 2 This is a schematic diagram of one of the structural embodiments of the second condenser in the third specific implementation.

[0027] Figure 3 This is a schematic diagram of another structure in a third specific embodiment of the second condenser;

[0028] Figure 4 This is a structural schematic diagram of the fourth specific embodiment of the second condenser;

[0029] Diagram description: Compressor 1; First check valve 2; First condenser 3; Second condenser 4; Refrigerant pump 5; Throttling element 6; Evaporator 7; Second check valve 8; Third check valve 9; Condenser fan 10; Evaporator fan 11; First water pump 12; First water tank 13; First precooling device 14; First manifold 15; Refrigerant pipe 16; Second manifold 17; Second water pump 18; Second water tank 19; Spray device 20; Second precooling device 21. Detailed Implementation

[0030] This invention discloses a dual-cycle refrigeration system and air conditioner with a compressor and a refrigerant pump, which solves the technical problems of small net positive suction head (NPSH) at the inlet of the refrigerant pump in existing dual-cycle refrigeration systems, which often result in cavitation and flow interruption.

[0031] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] Please see Figures 1 to 4 The present invention provides a dual-cycle refrigeration system of a compressor and a refrigerant pump, comprising:

[0034] The water circulation assembly and the compressor 1, first condenser 3, second condenser 4, refrigerant pump 5, throttling element 6 and evaporator 7 connected in sequence to form a closed refrigerant circuit;

[0035] The water circulation component is used to provide cooling water for heat exchange with the refrigerant in the second condenser 4.

[0036] In this embodiment, the liquid storage tank design in the existing dual-cycle system is eliminated. A second condenser 4 is connected to the refrigerant outlet of the first condenser 3. The first condenser 3 plays the main role in heat exchange of the refrigerant. After the refrigerant enters the second condenser 4 from the first condenser 3, the water circulation component provides cooling water to exchange heat with the refrigerant in the second condenser 4, thereby realizing secondary heat exchange of the refrigerant. In addition, the second condenser 4 also plays the role of liquid storage, effectively improving the subcooling at the inlet of the refrigerant pump 5. This solves the technical problems of cavitation and flow interruption that often occur at the inlet of the refrigerant pump 5, improves the operating efficiency and service life of the refrigerant pump 5, and ensures the energy-saving refrigeration effect of the dual-cycle refrigeration system of compressor 1 and refrigerant pump 5.

[0037] Furthermore, in this embodiment, the first condenser 3 is equipped with a condensing fan 10, which is used to drive outdoor air to exchange heat with the refrigerant in the first condenser 3.

[0038] Please see Figure 1 In one specific embodiment, the second condenser 4 is a shell-and-tube heat exchanger or a tubular heat exchanger.

[0039] It should be noted that in a shell-and-tube heat exchanger, the refrigerant flows through the shell side and the cooling water flows through the tube side; the heat of the refrigerant is absorbed by the water flowing through the inner tube and flows away; the gaseous refrigerant enters from the top, releases heat on the outer wall of the inner tube, cools down and condenses into liquid refrigerant, and flows out from the liquid outlet at the bottom; the shell side has a large internal volume, so the shell-and-tube heat exchanger can serve both as a cooling and condensing unit and as a liquid storage unit.

[0040] When the second condenser 4 is a shell-and-tube heat exchanger or a tubular heat exchanger, the water circulation assembly in this embodiment specifically includes a first water pump 12 and a first water storage tank 13. The inlet port of the first water pump 12 is connected to the first water storage tank 13, the outlet port of the first water pump 12 is connected to the cooling water inlet of the second condenser 4, and the cooling water outlet of the second condenser 4 is located above the first water storage tank 13.

[0041] It should be noted that the first water pump 12 pumps the cooling water in the first water tank 13 into the cooling water inlet of the second condenser 4. The cooling water carries away the heat of the refrigerant in the second condenser 4 and then circulates back to the first water tank 13 from the cooling water outlet of the second condenser 4, thus completing the cooling water circulation.

[0042] In addition, in low-temperature environments, the first condenser 3, the second condenser 4, and the water circulation components mentioned above can also operate without water. That is, the outdoor low-temperature air is driven by the condenser fan 10 to directly exchange heat with the refrigerant in the first condenser 3, effectively solving the technical problem that current spray direct evaporation condensers also need to use water evaporation and antifreeze at low temperatures.

[0043] Based on the structure of the water circulation component, the dual-cycle refrigeration system also includes a first pre-cooling device 14. Specifically, the first pre-cooling device 14 can be a spray-type pre-cooling device, and the first pre-cooling device 14 is located on the air inlet side of the first condenser 3.

[0044] It should be noted that the first precooling device 14 pre-cools and increases the humidity of the air passing through the first condenser 3, which is beneficial to improving the heat exchange effect of the first condenser 3. The water mist from the first precooling device condenses into water droplets and falls back into the first water storage tank 13. Through the above design, the heat exchange effect of the first condenser 3 in this embodiment is better than that of a conventional spray direct evaporation condenser. In addition, in the above design, the heat exchange cold source of the second condenser 4 actually utilizes the cooling water that falls back into the first water storage tank 13 from the first precooling device 14, which is equivalent to multi-stage utilization of cooling capacity, making the dual-cycle refrigeration system more energy-efficient.

[0045] Please see Figure 4 In the second specific embodiment, the second condenser 4 is a condenser coil.

[0046] When the second condenser 4 is a condensing coil, the water circulation assembly includes a second water pump 18, a second water storage tank 19, and a spray device 20.

[0047] The inlet port of the second water pump 18 is connected to the second water storage tank 19, the outlet port of the second water pump 18 is connected to the spray device 20, the second condenser 4 is located below the spray device 20, and the second water storage tank 19 is located below the spray device 20.

[0048] It should be noted that, through the above design, the second water pump 18 sprays the cooling water in the second water storage tank 19 into the spray device 20. The cooling water sprayed out by the spray device 20 falls directly onto the second condenser 4. Some of the cooling water will vaporize the latent heat on the surface of the second condenser 4 to carry away the heat of the refrigerant, while the other part of the cooling water falls directly into the second water storage tank 19 for circulation.

[0049] In addition, in low-temperature environments, the first condenser 3, the second condenser 4, and the water circulation components mentioned above can also operate without water. That is, the outdoor low-temperature air is driven by the condenser fan 10 to directly exchange heat with the refrigerant in the first condenser 3, effectively solving the technical problem that current spray direct evaporation condensers also need to use water evaporation and antifreeze at low temperatures.

[0050] Based on the structure of the water circulation components described above, the dual-circulation refrigeration system also includes a second pre-cooling device 21;

[0051] The second precooling device 21 is located on the air inlet side of the first condenser 3, and the second precooling device 21 is located below the spray device 20;

[0052] The second condenser 4 is located inside the second water storage tank 19, or the second condenser 4 is located between the spray device 20 and the second precooling device 21, or the second condenser 4 is located between the second precooling device 21 and the second water storage tank 19.

[0053] Specifically, when the second condenser 4 is inside the second water tank 19, the cooling water in the second water tank 19 soaks the second condenser 4, thereby absorbing the heat of the refrigerant inside the second condenser 4. When the second condenser 4 is between the spray device 20 and the second precooling device 21, the cooling water sprayed by the spray device 20 contacts the surface of the second condenser 4. Part of the cooling water vaporizes and carries away the heat of the refrigerant, while the other part of the cooling water falls directly into the second precooling device 21. When the second condenser 4 is between the second precooling device 21 and the second water tank 19, the cooling water falling from the second precooling device 21 contacts the surface of the second condenser 4. Part of the cooling water vaporizes and carries away the heat of the refrigerant, while the other part of the cooling water falls directly into the second water tank 19 to continue circulation.

[0054] It should be noted that, through the design of the second precooling device 21, the outdoor air, driven by the condenser fan 10, first passes through the second precooling device 21 to achieve preliminary cooling, and then flows over the surface of the first condenser 3 to exchange heat with the refrigerant inside the first condenser 3. The air after heat exchange is then discharged outdoors by the condenser fan 10. In the above design, when the outdoor air passes through the second precooling device 21, the latent heat of vaporization of water can be effectively utilized to reduce the inlet air temperature of the first condenser 3, which is beneficial to improving the heat exchange effect of the refrigerant inside the first condenser 3, and further reduces the operating load of the compressor 1, thus achieving energy-saving effects.

[0055] In addition, the second precooling device 21 in this embodiment can be a wet film or a packing space filled with packing material. The packing material in the packing space can slow down the water flow rate, allowing the cooling water to have a longer contact time with the outdoor air, and effectively cooling and humidifying the outdoor air by utilizing the latent heat of water vaporization; the wet film also plays the role of cooling the outdoor air by utilizing the latent heat of water vaporization.

[0056] Please see Figures 2 to 3 Furthermore, in this embodiment, the condenser coil specifically includes a first manifold 15, a second manifold 17, and a refrigerant pipe 16;

[0057] The inlet end of the refrigerant pipe 16 is connected to the first manifold 15, and the outlet end of the refrigerant pipe 16 is connected to the second manifold 17. The first manifold 15 is connected to the refrigerant outlet end of the first condenser 3, and the second manifold 17 is connected to the refrigerant inlet end of the refrigerant pump 5.

[0058] It should be noted that, in the above specific embodiment, the refrigerant coming out of the first condenser 3 enters the first manifold 15, then flows from the first manifold 15 to the refrigerant pipe 16, then from the refrigerant pipe 16 to the second manifold 17, and finally from the second manifold 17 to the refrigerant pump 5.

[0059] In addition, such as Figure 2 As shown, when the refrigerant pipe 16 is a straight-through copper or steel pipe, the first manifold 15 and the second manifold 17 can be respectively arranged opposite each other at both ends of the refrigerant pipe 16, and the refrigerant pipe 16 is inclined from the first manifold 15 toward the second manifold 17. Alternatively, as... Figure 3 As shown, when the refrigerant pipe 16 is a horizontal U-shaped copper or steel pipe, the first manifold 15 and the second manifold 17 are located on the same side of the refrigerant pipe 16 and are arranged vertically. Specifically, the position of the first manifold 15 is higher than the position of the second manifold 17.

[0060] In the above specific embodiments, the structure of the first condenser 3 and the second condenser 4 can combine water cooling, air cooling and evaporative cooling, which can achieve the technical effects of low power of condenser fan 10, low condensing pressure of compressor 1 and low power of compressor 1 / fluorine pump 5, which is conducive to improving the overall energy efficiency.

[0061] Furthermore, the evaporator 7 in this embodiment is equipped with an evaporation fan 11.

[0062] It should be noted that the aforementioned evaporator fan 11 is used to blow the cold air that has been heat-exchanged through the evaporator 7 into the room.

[0063] Furthermore, in this embodiment, the throttling element 6 is preferably an expansion valve.

[0064] Furthermore, in this embodiment, a first one-way valve 2 is provided between the compressor 1 and the first condenser 3.

[0065] It should be noted that the design of the first one-way valve 2 mentioned above can protect the compressor outlet and prevent refrigerant backflow.

[0066] Furthermore, it also includes a first bypass line and a second bypass line;

[0067] One end of the first bypass pipe is connected to the pipe between the first one-way valve 2 and the first condenser 3, and the other end of the first bypass pipe is connected to the pipe between the compressor 1 and the evaporator 7. A second one-way valve 8 is connected to the first bypass pipe.

[0068] One end of the second bypass pipe is connected to the pipe between the second condenser 4 and the refrigerant pump 5, and the other end of the second bypass pipe is connected to the pipe between the refrigerant pump 5 and the throttling element 6. A third one-way valve 9 is connected to the second bypass pipe.

[0069] Furthermore, based on the above structural description of the dual-cycle refrigeration system of compressor 1 and refrigerant pump 5, the operating strategy of the dual-cycle refrigeration system of compressor 1 and refrigerant pump 5 will be described in detail below:

[0070] Mode 1: Summer wet-bulb temperature > T1, compressor in wet mode 1, compressor circulation is activated, water circulation component is activated;

[0071] The circulation path of the dual-cycle refrigeration system is: compressor 1 → first check valve 2 → first condenser 3 → second condenser 4 → third check valve 9 → expansion valve → evaporator 7 → compressor 1;

[0072] The function of the second condenser 4 is: partial condensation and heat dissipation + subcooling + liquid storage. The water circulation component is turned on to pre-cool the second condenser 4.

[0073] Mode 2: During the transitional season, T1 < wet-bulb temperature < T2, a mixed wet mode is used, with 5 refrigerant pumps for natural cooling and 1 compressor for supplemental cooling, and the water circulation component is turned on;

[0074] ① Scheme 1: The circulation path of the dual-cycle refrigeration system is: compressor 1 → first check valve 2 → first condenser 3 → second condenser 4 → refrigerant pump 5 → expansion valve → evaporator 7 → second check valve 8;

[0075] Option 2: When using a dual-system backup, one dual-cycle refrigeration system operates with a refrigerant pump for circulation, while the other dual-cycle refrigeration system operates with a compressor for supplemental cooling.

[0076] The function of the second condenser 4 is: partial condensation and heat dissipation + subcooling + liquid storage;

[0077] Mode 3: Winter dry bulb temperature > T2, wet bulb temperature < T2, refrigerant pump 5 wet mode, refrigerant pump 5 natural cooling circulation, water circulation component on;

[0078] The circulation path of the dual-cycle refrigeration system is: refrigerant pump 5 → expansion valve → evaporator 7 → second check valve 8 → first condenser 3 → second condenser 4 → refrigerant pump 5;

[0079] The function of the second condenser 4 is: partial condensation and heat dissipation + subcooling + liquid storage;

[0080] Mode 4: In winter, when the dry bulb temperature is <T2, the refrigerant pump 5 is in dry mode, only the natural cooling circulation of the refrigerant pump 5 is activated, and the water circulation component is turned off;

[0081] The circulation path of the dual-cycle refrigeration system is: refrigerant pump 5 → expansion valve → evaporator 7 → second check valve 8 → first condenser 3 → second condenser 4 → refrigerant pump 5;

[0082] The function of the second condenser 4 is to store liquid only. At this time, the dry bulb temperature is too low, and the water circulation components are at risk of freezing.

[0083] Example 2

[0084] Please see Figure 1 An air conditioner provided in this embodiment of the invention specifically includes an electronic control device and the aforementioned dual-cycle refrigeration system of compressor and refrigerant pump.

[0085] In this embodiment of the air conditioner, the liquid storage tank design in the existing dual-cycle system is eliminated. A second condenser 4 is connected to the refrigerant outlet of the first condenser 3. The first condenser 3 plays the main role in heat exchange of the refrigerant. After the refrigerant enters the second condenser 4 from the first condenser 3, the water circulation component provides cooling water to exchange heat with the refrigerant in the second condenser 4, thereby realizing secondary heat exchange of the refrigerant. In addition, the second condenser 4 also plays the role of liquid storage, effectively improving the subcooling at the inlet of the refrigerant pump 5. This solves the technical problems of cavitation and flow interruption that often occur at the inlet of the refrigerant pump 5, improves the operating efficiency and service life of the refrigerant pump 5, and ensures the energy-saving cooling effect of the dual-cycle refrigeration system of the compressor and refrigerant pump.

[0086] The above provides a detailed description of a dual-cycle refrigeration system and air conditioner with a compressor and refrigerant pump provided by the present invention. For those skilled in the art, based on the ideas of the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A dual cycle refrigeration system of a compressor and a fluorine pump, characterized in that, The water circulation assembly is used for providing heat exchange between cooling water and refrigerant in the second condenser (4); and the second condenser (4) is a condensing coil. The water circulation assembly comprises a second water pump (18), a second water storage tank (19) and a spraying device (20). The water inlet port of the second water pump (18) is connected with the second water storage tank (19), the water outlet port of the second water pump (18) is connected with the spraying device (20), the second condenser (4) is located below the spraying device (20), and the second water storage tank (19) is located below the spraying device (20). The second pre-cooling device (21) is further included.

2. The dual cycle refrigerant system of claim 1 wherein, The first condenser (3) is provided with a condensing fan (10), the second pre-cooling device (21) is located at the air inlet side of the first condenser (3), and the second pre-cooling device (21) is located below the spraying device (20). The second condenser (4) is located in the second water storage tank (19), or the second condenser (4) is located between the spraying device (20) and the second pre-cooling device (21), or the second condenser (4) is located between the second pre-cooling device (21) and the second water storage tank (19). The first one-way valve (2) is arranged between the compressor (1) and the first condenser (3).

3. The dual cycle refrigerant system of claim 1 wherein, The first bypass pipeline and the second bypass pipeline are further included.

4. The dual cycle refrigerant system of claim 3 wherein, One end of the first bypass pipeline is connected to a pipeline between the first one-way valve (2) and the first condenser (3), the other end of the first bypass pipeline is connected to a pipeline between the compressor (1) and the evaporator (7), and a second one-way valve (8) is connected to the first bypass pipeline. One end of the second bypass pipeline is connected to a pipeline between the second condenser (4) and the fluorine pump (5), the other end of the second bypass pipeline is connected to a pipeline between the fluorine pump (5) and the throttling element (6), and a third one-way valve (9) is connected to the second bypass pipeline. The double-cycle refrigeration system comprises an electric control device and the compressor and the fluorine pump according to any one of claims 1 to 4.

5. An air conditioner characterized by comprising: ​

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