A carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil

Abstract

The present invention discloses a carbon dioxide heat pump system with the function of recovering the waste heat of lubricating oil, which comprises: a compressor, an oil-gas separator, a cooler, a fresh air intake device, a gas-liquid separator, a liquid storage tank, an expansion valve, an evaporator, an evaporator fan, a fresh air exhaust device, and an oil waste heat recovery device; the low-temperature refrigerant outlet of the gas-liquid separator is connected to the refrigerant inlet of the oil waste heat recovery device, the refrigerant outlet of the oil waste heat recovery device is connected to the refrigerant inlet of the compressor, the lubricating oil outlet of the oil-gas separator is connected to the lubricating oil inlet of the oil waste heat recovery device, and the lubricating oil outlet of the oil waste heat recovery device is connected to the lubricating oil inlet of the compressor. In the present invention, by setting the oil waste heat recovery device, the recovery of the heat of the lubricating oil is realized, and the temperature of the lubricating oil is reduced to the normal level.

Description

Technical Field

[0001] The invention relates to the technical field of heat pumps, and in particular to a carbon dioxide heat pump system with a lubricating oil waste heat recovery function. Background Art

[0002] As global environmental protection requirements become increasingly stringent, the application of environmentally friendly refrigerants has always been a hot topic in the HVAC and refrigeration industries. The international code for carbon dioxide refrigerant is R744, which is a pure natural refrigerant with a high volume ratio of volume refrigeration capacity. It is favored by the HVAC and refrigeration industries. With the rapid popularization of carbon dioxide refrigerants, heat pumps using carbon dioxide refrigerants are also being used more and more widely. In carbon dioxide heat pumps and carbon dioxide refrigeration systems, since carbon dioxide refrigerants are easily fused with lubricating oil, an oil separator must be installed, otherwise the lubricating oil in the compressor will follow the carbon dioxide refrigerant into the system, quickly causing the compressor to be short of oil, or even causing the compressor to burn out due to lack of effective lubrication. However, the existing carbon dioxide heat pump system has the following problems: the heat in the lubricating oil is lost to the outside air when passing through the lubricating oil radiator, resulting in heat energy waste; there is no fresh air device, and the fresh air device needs to be purchased and installed separately, which prolongs the installation time and increases the cost.

[0003] In the prior art, Chinese utility model patent application number CN201921788566.X proposes a carbon dioxide compressor and a refrigeration system thereof. The carbon dioxide compressor includes: a housing, a motor, a cylinder assembly and an exhaust distributor. The cylinder assembly includes: a first cylinder for performing two-stage compression and a second cylinder for performing one-stage compression; an upper cover exhaust port is provided on the housing, and the first exhaust port of the first cylinder is connected to the cavity of the housing. After the gas is discharged from the first exhaust port, it enters the cavity and is then discharged from the compressor through the upper cover exhaust port; the second exhaust port of the second cylinder is connected to the inlet of the exhaust distributor. The utility model effectively reduces the pressure of the compressor and the refrigeration system, reduces the exhaust temperature of the compressor, and improves the working efficiency of the compressor; by limiting the volume ratio of the first cylinder and the second cylinder and the ratio of the volume of the two cylinders to the exhaust area, the air replenishment structure required by the existing two-stage compressor is removed, the air flow turbulence caused by the air replenishment structure is avoided, and the stability of the compressor operation is improved. However, the heat of the compressor lubricating oil in the utility model patent application is not recycled, resulting in heat energy waste, and there is no integrated fresh air device, resulting in extended installation time and increased costs. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a carbon dioxide heat pump system with a lubricating oil waste heat recovery function.

[0005] The carbon dioxide heat pump system with the function of recovering the waste heat of lubricating oil includes: a compressor, an oil-gas separator, a cooler, a fresh air intake device, a gas-liquid separator, a liquid storage tank, an expansion valve, an evaporator, an evaporator fan, a fresh air exhaust device, and an oil waste heat recovery device; the refrigerant outlet of the compressor on the compressor is connected to the refrigerant inlet of the oil-gas separator on the oil-gas separator through a refrigerant pipeline, the refrigerant outlet of the oil-gas separator on the oil-gas separator is connected to the refrigerant inlet of the cooler on the cooler through a refrigerant pipeline, the refrigerant outlet of the cooler on the cooler is connected to the high-temperature refrigerant inlet of the gas-liquid separator on the upper right side of the gas-liquid separator through a refrigerant pipeline via the fresh air intake device, the heat transfer medium inlet and the heat transfer medium outlet of the cooler are respectively connected to the heating pipeline, the high-temperature refrigerant outlet of the gas-liquid separator on the lower right side of the gas-liquid separator is connected to the liquid storage tank, the expansion valve, and the evaporator in sequence through a refrigerant pipeline, the evaporator is connected to the low-temperature refrigerant inlet of the gas-liquid separator at the bottom of the gas-liquid separator through a refrigerant pipeline via the fresh air exhaust device, the evaporator fan for increasing the air flow is fixed on the top of the evaporator, the low-temperature refrigerant outlet of the gas-liquid separator at the top of the gas-liquid separator is connected to the refrigerant inlet of the oil waste heat recovery device on the upper left side of the oil waste heat recovery device through a refrigerant pipeline, the refrigerant outlet of the oil waste heat recovery device on the upper right side of the oil waste heat recovery device is connected to the refrigerant inlet of the compressor on the left side of the compressor through a refrigerant pipeline, the lubricating oil outlet of the oil-gas separator at the bottom of the oil-gas separator is connected to the lubricating oil inlet of the oil waste heat recovery device on the oil waste heat recovery device through a lubricating oil pipeline, and the lubricating oil outlet of the oil waste heat recovery device on the oil waste heat recovery device is connected to the lubricating oil inlet of the compressor at the bottom of the compressor through a lubricating oil pipeline.

[0006] Further, the oil waste heat recovery device is a heat pipe heat exchanger, including: a recovery device upper shell, a recovery device lower shell connected to the bottom of the recovery device upper shell, an oil waste heat recovery device partition connected to the top of the recovery device lower shell, and the oil waste heat recovery device partition divides the internal cavity of the oil waste heat recovery device into an oil waste heat recovery device upper channel for passing refrigerant located above the oil waste heat recovery device partition and an oil waste heat recovery device lower channel for passing lubricating oil located below the oil waste heat recovery device partition 11.7. Heat pipe holes are provided on the oil waste heat recovery device partition, and heat pipe elements for heat exchange are inserted and fixed in the heat pipe holes. The upper part of the heat pipe element is located in the oil waste heat recovery device upper channel, and the lower part is located in the oil waste heat recovery device lower channel.

[0007] Further, the oil-gas separator is a cyclone oil-gas separator.

[0008] Further, a float valve for controlling the liquid level height of the lubricating oil is arranged inside the oil-gas separator and connected to the lubricating oil outlet of the oil-gas separator.

[0009] Further, a coil pipe for cooling is wound and fixed on the outer surface of the oil-gas separator. The upper end of the coil pipe is connected to the low-temperature refrigerant outlet of the gas-liquid separator, and the lower end is connected to the refrigerant inlet of the compressor.

[0010] Further, the oil waste heat recovery device further includes a proportional regulating valve for regulating the lubricating oil flow rate, which is arranged on the lubricating oil pipeline connected to the lubricating oil inlet of the oil waste heat recovery device.

[0011] Further, the oil waste heat recovery device further includes an oil temperature sensor for detecting the lubricating oil temperature, which is arranged on the lubricating oil pipeline connected to the lubricating oil outlet of the oil waste heat recovery device.

[0012] Further, the fresh air intake device includes: an intake device housing, an intake radiator arranged in the intake device housing, and an intake fan connected to the inner wall of the intake device housing.

[0013] Further, the fresh air exhaust device includes: an exhaust device housing, an exhaust radiator arranged in the exhaust device housing, and an exhaust fan connected to the inner wall of the exhaust device housing.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. For the carbon dioxide heat pump system with the lubricating oil waste heat recovery function, by setting up the oil waste heat recovery device, both the recovery of the lubricating oil heat and the reduction of the lubricating oil temperature to the normal level are achieved.

[0016] 2. For the carbon dioxide heat pump system with the lubricating oil waste heat recovery function, by setting up the fresh air heat exchanger and the exhaust air heat exchanger, the integration of the fresh air device is realized, the repeated construction of the fresh air device is avoided, and the construction time and cost are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are schematic structural diagrams of the present invention.

[0018] As shown in the figure markings: 1 - compressor, 1.1 - refrigerant inlet of the compressor, 1.2 - refrigerant outlet of the compressor, 1.3 - lubricating oil inlet of the compressor, 2 - oil-gas separator, 2.1 - refrigerant inlet of the oil-gas separator, 2.2 - refrigerant outlet of the oil-gas separator, 2.3 - lubricating oil outlet of the oil-gas separator, 3 - cooler, 3.1 - refrigerant inlet of the cooler, 3.2 - refrigerant outlet of the cooler, 3.3 - heat transfer medium inlet, 3.4 - heat transfer medium outlet, 4 - fresh air intake device, 4.1 - housing of the intake device, 4.2 - intake radiator, 4.3 - intake fan, 5 - gas-liquid separator, 5.1 - high-temperature refrigerant inlet of the gas-liquid separator, 5.2 - high-temperature refrigerant outlet of the gas-liquid separator, 5.3 - low-temperature refrigerant outlet of the gas-liquid separator, 5.4 - low-temperature refrigerant inlet of the gas-liquid separator, 6 - liquid storage tank, 7 - expansion valve, 8 - evaporator, 9 - evaporator fan, 10 - fresh air exhaust device, 10.1 - housing of the exhaust device, 10.2 - exhaust radiator, 10.3 - exhaust fan, 11 - oil waste heat recovery device, 11.1 - refrigerant inlet of the oil waste heat recovery device, 11.2 - refrigerant outlet of the oil waste heat recovery device, 11.3 - lubricating oil inlet of the oil waste heat recovery device, 11.4 - lubricating oil outlet of the oil waste heat recovery device, 11.5 - upper channel of the oil waste heat recovery device, 11.6 - lower channel of the oil waste heat recovery device, 11.7 - partition of the oil waste heat recovery device, 11.8 - heat pipe element, 11.9 - upper housing of the recovery device, 11.10 - lower housing of the recovery device, 12 - coil, 13 - lubricating oil pipeline. Detailed implementation manners

[0019] The following clearly and completely describes the detailed implementation manners of the carbon dioxide heat pump system with lubricating oil waste heat recovery function according to the present invention in conjunction with the accompanying drawings of the specification.

[0020] As shown in the attached drawings, the carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil includes: a compressor 1, an oil-gas separator 2, a cooler 3, a fresh air intake device 4, a gas-liquid separator 5, a liquid storage tank 6, an expansion valve 7, an evaporator 8, an evaporator fan 9, a fresh air exhaust device 10, and an oil waste heat recovery device 11; the refrigerant outlet 1.2 of the compressor on the compressor 1 is connected to the refrigerant inlet 2.1 of the oil-gas separator on the oil-gas separator 2 through a refrigerant pipeline (not shown in the figure), the refrigerant outlet 2.2 of the oil-gas separator on the oil-gas separator 2 is connected to the refrigerant inlet 3.1 of the cooler on the cooler 3 through a refrigerant pipeline, the refrigerant outlet 3.2 of the cooler on the cooler 3 is connected to the high-temperature refrigerant inlet 5.1 of the gas-liquid separator at the upper right of the gas-liquid separator 5 through a refrigerant pipeline via the fresh air intake device 4, the heat transfer medium inlet 3.3 and the heat transfer medium outlet 3.4 of the cooler 3 are respectively connected to a heating pipeline (not shown in the figure), the high-temperature refrigerant outlet 5.2 of the gas-liquid separator at the lower right of the gas-liquid separator 5 is connected to the liquid storage tank 6, the expansion valve 7, and the evaporator 8 in sequence through a refrigerant pipeline, the evaporator 8 is connected to the low-temperature refrigerant inlet 5.4 at the bottom of the gas-liquid separator 5 through a refrigerant pipeline via the fresh air exhaust device 10, the evaporator fan 9 for increasing the air flow is fixed on the top of the evaporator 8, the low-temperature refrigerant outlet 5.3 at the top of the gas-liquid separator 5 is connected to the refrigerant inlet 11.1 at the upper left of the oil waste heat recovery device 11 through a refrigerant pipeline, the refrigerant outlet 11.2 at the upper right of the oil waste heat recovery device 11 is connected to the refrigerant inlet 1.1 at the left of the compressor 1 through a refrigerant pipeline, the lubricating oil outlet 2.3 of the oil-gas separator at the bottom of the oil-gas separator 2 is connected to the lubricating oil inlet 11.3 of the oil waste heat recovery device on the oil waste heat recovery device 11 through a lubricating oil pipeline 13, and the lubricating oil outlet 11.4 of the oil waste heat recovery device on the oil waste heat recovery device 11 is connected to the lubricating oil inlet 1.3 at the bottom of the compressor 1 through a lubricating oil pipeline 13.

[0021] Further, the oil waste heat recovery device 11 is a heat pipe heat exchanger, including: a recovery device upper housing 11.9, a recovery device lower housing 11.10 connected to the bottom of the recovery device upper housing 11.9, an oil waste heat recovery device partition 11.7 connected to the top of the recovery device lower housing 11.10, the oil waste heat recovery device partition 11.7 divides the internal cavity of the oil waste heat recovery device 11 into an oil waste heat recovery device upper channel 11.5 for passing refrigerant above the oil waste heat recovery device partition 11.7 and an oil waste heat recovery device lower channel 11.6 for passing lubricating oil below the oil waste heat recovery device partition 11.7, a heat pipe hole (not shown in the figure) is provided on the oil waste heat recovery device partition 11.7, and the heat pipe element 11.8 for heat exchange is inserted and fixed in the heat pipe hole, the upper part of the heat pipe element 11.8 is located in the oil waste heat recovery device upper channel 11.5, and the lower part is located in the oil waste heat recovery device lower channel 11.6.

[0022] Further, the oil-gas separator 2 is a cyclone oil-gas separator.

[0023] Further, a float valve (not shown in the figure) for controlling the lubricating oil liquid level is arranged inside the oil-gas separator 2 and connected to the lubricating oil outlet 2.3 of the oil-gas separator.

[0024] Further, a coil pipe 12 for cooling is wound and fixed on the outer surface of the oil-gas separator 2. The upper end of the coil pipe 12 is connected to the low-temperature refrigerant outlet 5.3 of the gas-liquid separator, and the lower end is connected to the refrigerant inlet 1.1 of the compressor.

[0025] Further, the oil waste heat recovery device 11 further includes a proportional regulating valve (not shown in the figure) for adjusting the lubricating oil flow rate arranged on the lubricating oil pipeline 13 connected to the lubricating oil inlet 11.3 of the oil waste heat recovery device.

[0026] Further, the oil waste heat recovery device 11 further includes an oil temperature sensor (not shown in the figure) for detecting the lubricating oil temperature arranged on the lubricating oil pipeline 13 connected to the lubricating oil outlet 11.4 of the oil waste heat recovery device.

[0027] Further, the fresh air intake device 4 includes: an intake device housing 4.1, an intake radiator 4.2 arranged inside the intake device housing 4.1, and an intake fan 4.3 connected to the inner wall of the intake device housing 4.1.

[0028] Further, the fresh air exhaust device 10 includes: an exhaust device housing 10.1, an exhaust radiator 10.2 arranged inside the exhaust device housing 10.1, and an exhaust fan 10.3 connected to the inner wall of the exhaust device housing 10.1.

[0029] The working principle of the carbon dioxide heat pump system with lubricating oil waste heat recovery function according to the present invention is briefly introduced as follows in combination with the accompanying drawings of the specification:

[0030] When the carbon dioxide heat pump system with lubricating oil waste heat recovery function is working, the refrigerant is compressed by the compressor 1 to become a refrigerant containing lubricating oil, and then enters the oil-gas separator 2. Under the action of the oil-gas separator 2, the lubricating oil remains at the bottom of the oil-gas separator 2, and the refrigerant without lubricating oil is discharged from the oil-gas separator refrigerant outlet 2.2, enters the cooler 3 and exchanges heat with the heat transfer medium flowing in from the heating pipeline; the refrigerant after heat exchange first passes through the air intake radiator 4.2 to exchange heat with the cold air entering the room, and then enters the gas-liquid separator 5 to exchange heat with the refrigerant discharged from the exhaust radiator 10.2. The vapor contained in the refrigerant passing through the gas-liquid separator 5 It condenses into liquid and enters the liquid storage tank 6 together with the refrigerant. The liquid remains in the liquid storage tank 6, and the refrigerant is discharged from the liquid storage tank 6. After passing through the expansion valve 7, the refrigerant is rapidly decompressed and cooled and enters the evaporator 8. When passing through the evaporator 8, the refrigerant absorbs heat from the outside air, and then enters the exhaust radiator 10.2. When passing through the exhaust radiator 10.2, it exchanges heat with the room temperature air discharged to the outside, and the temperature rises. Then it passes through the gas-liquid separator 5 and exchanges heat with the refrigerant discharged from the intake radiator 4.2. The temperature further rises, and then it enters the oil waste heat recovery device 11, absorbs heat from the high-temperature lubricating oil through the heat pipe element 11.8, and finally returns to the compressor 1, and the cycle continues.

[0031] When the carbon dioxide heat pump system with lubricating oil waste heat recovery function is working, the lubricating oil in the refrigerant accumulates at the bottom of the oil-gas separator 2 under the action of the oil-gas separator 2. When the set liquid level of the float valve inside the oil-gas separator 2 is reached, the float valve opens, and the lubricating oil leaves the oil-gas separator 2 under the action of the refrigerant pressure, enters the oil waste heat recovery device 11 to exchange heat with the refrigerant, and then returns to the compressor 1, and the cycle continues. In addition, the coil 12 welded on the outer wall of the oil-gas separator 2 flows with low-temperature refrigerant, which can cool the oil-gas separator 2 and enhance the condensation effect of the oil-gas separator 2.

[0032] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be thought of by those skilled in the art shall fall into the protection scope of the present invention.

Claims

1. A carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil, characterized in that, The carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil includes: a compressor (1), an oil-gas separator (2), a cooler (3), a fresh air intake device (4), a gas-liquid separator (5), a liquid storage tank (6), an expansion valve (7), an evaporator (8), an evaporator fan (9), a fresh air exhaust device (10), and an oil waste heat recovery device (11); the refrigerant outlet (1.2) of the compressor on the compressor (1) is connected to the refrigerant inlet (2.1) of the oil-gas separator on the oil-gas separator (2) through a refrigerant pipeline, the refrigerant outlet (2.2) of the oil-gas separator on the oil-gas separator (2) is connected to the refrigerant inlet (3.1) of the cooler on the cooler (3) through a refrigerant pipeline, the refrigerant outlet (3.2) of the cooler on the cooler (3) is connected to the high-temperature refrigerant inlet (5.1) of the gas-liquid separator at the upper right of the gas-liquid separator (5) through a refrigerant pipeline via the fresh air intake device (4), the heat transfer medium inlet (3.3) and the heat transfer medium outlet (3.4) on the cooler (3) are respectively connected to a heating pipeline, the high-temperature refrigerant outlet (5.2) of the gas-liquid separator at the lower right of the gas-liquid separator (5) is connected to the liquid storage tank (6), the expansion valve (7), and the evaporator (8) in sequence through a refrigerant pipeline, the evaporator (8) is connected to the low-temperature refrigerant inlet (5.4) of the gas-liquid separator at the bottom of the gas-liquid separator (5) through a refrigerant pipeline via the fresh air exhaust device (10), the evaporator fan (9) is fixed at the top of the evaporator (8), the low-temperature refrigerant outlet (5.3) of the gas-liquid separator at the top of the gas-liquid separator (5) is connected to the refrigerant inlet (11.1) of the oil waste heat recovery device at the upper left of the oil waste heat recovery device (11) through a refrigerant pipeline, the refrigerant outlet (11.2) of the oil waste heat recovery device at the upper right of the oil waste heat recovery device (11) is connected to the refrigerant inlet (1.1) of the compressor on the left side of the compressor (1) through a refrigerant pipeline, the lubricating oil outlet (2.3) of the oil-gas separator at the bottom of the oil-gas separator (2) is connected to the lubricating oil inlet (11.3) of the oil waste heat recovery device on the oil waste heat recovery device (11) through a lubricating oil pipeline (13), and the lubricating oil outlet (11.4) of the oil waste heat recovery device on the oil waste heat recovery device (11) is connected to the lubricating oil inlet (1.3) of the compressor at the bottom of the compressor (1) through a lubricating oil pipeline (13); The oil-gas separator (2) is a cyclone oil-gas separator; A coiled pipe (12) is wound and fixed on the outer surface of the oil-gas separator (2), the upper end of the coiled pipe (12) is connected to the low-temperature refrigerant outlet (5.3) of the gas-liquid separator, and the lower end is connected to the refrigerant inlet (1.1) of the compressor; A float valve connected to the lubricating oil outlet (2.3) of the oil-gas separator is arranged inside the oil-gas separator (2).

2. The carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil according to claim 1, characterized in that, The oil waste heat recovery device (11) is a heat pipe heat exchanger, including: a recovery device upper housing (11.9), a recovery device lower housing (11.10) connected to the bottom of the recovery device upper housing (11.9), a partition (11.7) of the oil waste heat recovery device is connected to the top of the recovery device lower housing (11.10), and the partition (11.7) of the oil waste heat recovery device divides the internal cavity of the oil waste heat recovery device (11) into an upper channel (11.5) of the oil waste heat recovery device located above the partition (11.7) of the oil waste heat recovery device and a lower channel (11.6) of the oil waste heat recovery device located below the partition (11.7) of the oil waste heat recovery device. Heat pipe holes are provided on the partition (11.7) of the oil waste heat recovery device, and heat pipe elements (11.8) are inserted and fixed in the heat pipe holes. The upper parts of the heat pipe elements (11.8) are located in the upper channel (11.5) of the oil waste heat recovery device, and the lower parts are located in the lower channel (11.6) of the oil waste heat recovery device.

3. The carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil according to claim 1, characterized in that, The oil waste heat recovery device (11) further includes a proportional regulating valve provided on a lubricating oil pipeline (13) connected to an oil waste heat recovery device lubricating oil inlet (11.3).

4. The carbon dioxide heat pump system with the function of recovering the waste heat of lubricating oil according to claim 3, characterized in that, The oil waste heat recovery device (11) further includes an oil temperature sensor provided on a lubricating oil pipeline (13) connected to an oil waste heat recovery device lubricating oil outlet (11.4).

5. The carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil according to claim 1, characterized in that The fresh air intake device (4) includes: an intake device housing (4.1), an intake radiator (4.2) provided in the intake device housing (4.1), and an intake fan (4.3) connected to the inner wall of the intake device housing (4.1).

6. The carbon dioxide heat pump system with the function of recovering waste heat of lubricating oil according to claim 1, wherein, The fresh air exhaust device (10) includes: an exhaust device housing (10.1), an exhaust radiator (10.2) provided in the exhaust device housing (10.1), and an exhaust fan (10.3) connected to the inner wall of the exhaust device housing (10.1).

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