Refrigerating unit

Abstract

The utility model relates to the technical field of refrigerating equipment, in particular to a refrigerating unit. A refrigerating loop of the refrigerating unit comprises a condenser, a throttling device, an evaporator and a compressor which are communicated through a pipeline; the throttling device comprises a rotating shaft, a first shell and an expansion wheel arranged in the first shell, the rotating shaft is coaxially and fixedly connected with the expansion wheel, a first inlet and a first outlet are formed in the first shell, and after entering the first shell through the first inlet, a refrigerant pushes the expansion wheel to rotate to do work and then is discharged from the first outlet; the throttling device further comprises a second shell and a compression wheel arranged in the second shell, the rotating shaft is coaxially and fixedly connected with the compression wheel, a second inlet and a second outlet are formed in the second shell, and a refrigerant discharged by the evaporator enters the second shell through the second inlet, is compressed by the compression wheel and then is discharged from the second outlet. The air suction pressure of the compressor is improved, the power consumption of the compressor is reduced, and recycling of energy recycled in the throttling process of the throttling device is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration equipment, and in particular to a refrigeration unit. Background Art

[0002] Centrifugal compressors, as the main refrigeration equipment, are widely used in machinery, automobile, medical, food, electricity, building materials, petroleum, chemical and military industries.

[0003] Centrifugal refrigeration units mainly include evaporators, condensers, flash units, throttling devices and compressors. The throttling device usually uses throttling elements such as expansion valves or capillary tubes. This type of throttling element will play a role in throttling and reducing pressure during the working process, that is, throttling and cooling the high-temperature and high-pressure refrigerant to obtain low-temperature and low-pressure refrigerant. In this throttling process, the pressure and temperature are reduced, which will cause part of the energy to be dissipated and cannot be effectively collected and utilized. This part of the energy comes from the compression work of the compressor on the refrigerant, which is equivalent to wasting part of the compressor's power. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a refrigeration unit.

[0005] According to the refrigeration unit provided in the embodiment of the present application, the refrigeration circuit of the refrigeration unit includes a condenser, a throttling device, an evaporator and a compressor connected by pipelines;

[0006] The throttling device comprises a rotating shaft, a first shell and an expansion wheel arranged in the first shell, the rotating shaft is coaxially fixedly connected with the expansion wheel, the first shell is provided with a first inlet and a first outlet, after the refrigerant enters the first shell through the first inlet, it drives the expansion wheel to rotate and do work, and then is discharged from the first outlet;

[0007] The throttling device also includes a second shell and a compression wheel arranged in the second shell. The rotating shaft is coaxially and fixedly connected to the compression wheel. The second shell is provided with a second inlet and a second outlet. The refrigerant discharged from the evaporator enters the second shell through the second inlet, is compressed by the compression wheel and is discharged from the second outlet.

[0008] Furthermore, the refrigeration unit further comprises a gas-liquid separator, which is configured to receive the refrigerant discharged from the second outlet and supply gaseous refrigerant to the compressor.

[0009] Furthermore, the compressor is a two-stage compressor, and the refrigeration circuit also includes a flasher, which is arranged between the condenser and the evaporator, and an air supply branch is provided between the exhaust port of the flasher and the air supply port of the two-stage compressor.

[0010] Further, the throttling device includes a first throttling device and a second throttling device, the first throttling device is arranged between the condenser and the flasher, and the second throttling device is arranged between the flasher and the evaporator.

[0011] Further, at least one of the first throttling device and the second throttling device includes the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel.

[0012] Furthermore, the first throttling device and the second throttling device both include the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel, the second inlet of the first throttling device and the second inlet of the second throttling device are both connected to the evaporator, and the second outlet of the first throttling device and the second outlet of the second throttling device are both connected to the gas-liquid separator.

[0013] Furthermore, the first throttling device and the second throttling device both include the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel, the second inlet of the second throttling device is connected to the evaporator, the second outlet of the second throttling device is connected to the second inlet of the first throttling device, and the second outlet of the first throttling device is connected to the gas-liquid separator.

[0014] Furthermore, the liquid discharge port of the gas-liquid separator is connected to the evaporator via a liquid discharge pipeline.

[0015] Furthermore, the refrigeration unit further comprises a cooling circuit, the cooling circuit comprises a driving component and a cooling pipeline, the cooling pipeline is configured to perform heat exchange with the part to be radiated. The driving component is configured to drive the liquid in the gas-liquid separator to flow in the cooling circuit.

[0016] Furthermore, the rotating shaft is supported by a gas bearing.

[0017] The present application proposes a refrigeration unit with a throttling energy recovery function, in which the relatively high-pressure gas in the throttling device drives the expansion wheel to operate, and then drives the compression wheel to rotate through the rotating shaft, so that the compression wheel sucks in the gaseous refrigerant through the second inlet and compresses it to do work, thereby increasing the pressure of the gaseous refrigerant. The gaseous refrigerant is sucked away by the compressor and compressed again and then enters the condenser. Due to the work done by the compression wheel, the suction pressure of the compressor is increased, the power consumption of the compressor is reduced, and the reuse of energy recovered in the throttling process of the throttling device is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of a refrigeration unit provided in an embodiment of the present application is schematically given;

[0020] Figure 2 The structural diagram of the throttling device provided in the embodiment of the present application is schematically given;

[0021] Figure 3 The structure diagram of the second refrigeration unit provided in the embodiment of the present application is schematically given;

[0022] Figure 4 The structure diagram of the third refrigeration unit provided in the embodiment of the present application is schematically given;

[0023] Figure 5 A schematic diagram of the structure of a refrigeration unit in the related art is given schematically;

[0024] Figure 6 The structure diagram of the fourth refrigeration unit provided in the embodiment of the present application is schematically given;

[0025] Figure 7 A cross-sectional structural diagram of an ejector provided in an embodiment of the present application is schematically provided;

[0026] Figure 8 The structure diagram of the fifth refrigeration unit provided in the embodiment of the present application is schematically given;

[0027] Fig. 9 The structure diagram of the sixth refrigeration unit provided in the embodiment of the present application is schematically given;

[0028] Fig.10 A pressure-enthalpy diagram of a partial cycle process in a refrigeration unit provided in an embodiment of the present application is schematically shown.

[0029] In the figure:

[0030] 100. Condenser;

[0031] 200, throttling device; 210, first throttling device; 220, second throttling device; 201, rotating shaft; 202, first housing; 203, expansion wheel; 204, first inlet; 205, first outlet; 206, second housing; 207, compression wheel; 208, second inlet; 209, second outlet; 211, gas bearing;

[0032] 300, evaporator,

[0033] 400, gas-liquid separator;

[0034] 500. Compressor;

[0035] 600, controller;

[0036] 710, ejector; 711, ejection flow inlet; 712, outlet; 713, ejection flow inlet; 714, ejection portion; 715, housing; 716, receiving chamber; 717, mixing chamber; 718, diffusion chamber; 719, adjustment needle;

[0037] 720, high pressure pipeline; 730, low pressure pipeline; 740, cooling pipeline;

[0038] 810, flash device; 820, air supply branch. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0040] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a system, product or device comprising a series of units is not necessarily limited to those units explicitly listed, but may include units that are not explicitly listed or inherent to these products or devices.

[0041] In this application, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", "outer", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0042] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0043] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0045] The present application discloses a refrigeration unit, which includes a refrigeration circuit. Figure 1 As shown, the refrigeration circuit mainly includes a condenser 100, a throttling device 200, an evaporator 300, and a compressor 500 which are connected by pipelines. When the refrigeration unit is used to refrigerate a water system, the evaporator 300 mainly realizes refrigeration by absorbing heat through the refrigerant to lower the temperature of the water system; the condenser 100 mainly transfers the heat of the superheated gas of the refrigerant to the water system to achieve cooling of the refrigerant; the throttling device 200 mainly functions to throttle and cool the high-pressure refrigerant flowing out of the condenser 100 to achieve the pressure on the evaporator 300 side, and the pressure change in this process is dissipated through the throttling device 200; the compressor 500 mainly functions to realize the compression of the refrigerant, and convert the low-temperature and low-pressure refrigerant into the high-temperature and high-pressure refrigerant, which is achieved by consuming electrical energy in this process. Specifically, Figure 1 In the system shown, when the refrigeration unit is in normal operation, the compressor 500 absorbs low-temperature and low-pressure gaseous refrigerant and compresses it to produce high-temperature and high-pressure gaseous refrigerant. After the high-temperature and high-pressure gaseous refrigerant enters the condenser 100, the condenser 100 transfers the heat of the superheated gas of the refrigerant to the water system to achieve cooling of the refrigerant, and obtains medium-temperature and high-pressure liquid refrigerant. Then, the throttling and cooling effect of the throttling device 200 is further used to achieve the pressure on the evaporator 300 side. The refrigerant absorbs heat in the evaporator 300 to lower the temperature of the water system to achieve the refrigeration function. The low-temperature and low-pressure refrigerant discharged from the evaporator 300 is sucked into the compressor 500 and compressed again.

[0046] In the related art, the throttling device 200 usually uses a throttling element such as an expansion valve or a capillary tube. This type of throttling element will play a role of throttling and reducing pressure during the working process, that is, throttling and cooling the high-temperature and high-pressure refrigerant to obtain a low-temperature and low-pressure refrigerant. In this throttling process, the pressure and temperature are reduced, which will cause part of the energy to be dissipated and cannot be effectively collected and utilized. This part of the energy comes from the compression work of the compressor on the refrigerant, which is equivalent to wasting part of the power of the compressor.

[0047] Based on this, Figure 1 and 2 As shown, the present application provides a novel throttling device 200, which includes a rotating shaft 201, a first shell 202, and an expansion wheel 203 disposed in the first shell 202. The rotating shaft 201 is coaxially fixedly connected with the expansion wheel 203. The first shell 202 is provided with a first inlet 204 and a first outlet 205. The first inlet 204 is connected to the condenser 100 through a pipeline. After the high-pressure liquid refrigerant flowing out of the condenser 100 enters the first shell 202 through the first inlet 204, it pushes the expansion wheel 203 to rotate and do work, and then becomes a low-temperature and low-pressure refrigerant, which is then discharged from the first outlet 205. In this process, the rotating shaft 201 will rotate synchronously with the expansion wheel 203, and the throttling device 200 realizes throttling and reducing the pressure of the refrigerant while converting the energy into kinetic energy that is beneficial to be utilized, thereby realizing energy recovery during the throttling process.

[0048] In order to realize the utilization of energy recovered by the throttling device 200 during the throttling process, as Figure 1 As shown, the throttling device 200 further includes a second shell 206 and a compression wheel 207 disposed in the second shell 206. The rotating shaft 201 is coaxially fixedly connected with the compression wheel 207. The second shell 206 is provided with a second inlet 208 and a second outlet 209. The refrigerant discharged from the evaporator 300 enters the second shell 206 through the second inlet 208, is compressed by the compression wheel 207, and is discharged from the second outlet 209. The relatively high-pressure gas in the throttling device 200 drives the expansion wheel 203 to operate, and then drives the compression wheel 207 to rotate through the rotating shaft 201, so that the compression wheel 207 inhales the gaseous refrigerant through the second inlet 208 and compresses it to do work, thereby increasing the pressure of the gaseous refrigerant. The gaseous refrigerant is sucked away by the compressor 500 again and compressed and enters the condenser 100. Due to the work done by the compression wheel 207, the suction pressure of the compressor 500 is increased, the power consumption of the compressor 500 is reduced, and the energy recovered during the throttling process of the throttling device 200 is reused.

[0049] In some embodiments, the refrigeration unit further includes a gas-liquid separator 400, which is configured to receive the refrigerant discharged from the second outlet of the throttling device and supply gaseous refrigerant to the compressor. The refrigerant discharged from the second outlet of the throttling device enters the gas-liquid separator 400 to achieve gas-liquid separation. After the gaseous refrigerant flowing out of the evaporator 300 is compressed by the compression wheel 207 of the throttling device 200, there will be pressure loss and heat release during the flow process, so that liquid will be generated. The main purpose of the gas-liquid separator 400 is to separate the liquid from the gas in the refrigerant to achieve normal air intake of the compressor 500 and prevent the compressor 500 from inhaling liquid.

[0050] In some embodiments, Figure 3 and4 As shown, the compressor 500 is a two-stage compressor, and the refrigeration circuit also includes a flasher 810, which is arranged between the condenser 100 and the evaporator 300, and an air supply branch 820 is arranged between the exhaust port of the flasher 810 and the air supply port of the two-stage compressor. The flasher 810 can further throttle the liquid of the condenser 100, and produce medium and low temperature refrigerant for the secondary air supply and cooling of the compressor 500. When the refrigeration unit is in the normal operation process, the two-stage compressor absorbs the low-temperature and low-pressure gaseous refrigerant from the gas-liquid separator 400 and reaches the intermediate pressure after the first-stage compression. At this time, the gas after the first-stage compression is in an overheated state, and then the gas is supplemented through the exhaust port and the air supply port of the flasher 810 to cool down, and then the set pressure is reached by performing the second-stage compression. Since the power consumed by the second-stage compression is reduced through the intermediate cooling, the energy efficiency level of the refrigeration unit is indirectly improved.

[0051] Based on the above implementation, Figure 3 and 4 As shown, the throttling device 200 includes a first throttling device 210 and a second throttling device 220. The first throttling device 210 is arranged between the condenser 100 and the flash evaporator 810, and the second throttling device 220 is arranged between the flash evaporator 810 and the evaporator 300. During the operation of the refrigeration unit, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 500 is condensed by the condenser 100 to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is throttled and depressurized by the first throttling device 210 to obtain a medium-temperature and medium-pressure gas-liquid two-phase refrigerant, and then enters the flash evaporator 810. The liquid refrigerant at the bottom of the flash evaporator 810 continues to be throttled and depressurized by the second throttling device 220 to become a low-temperature and low-pressure refrigerant, and finally enters the evaporator 300 to complete heat absorption and gasification. The first throttling device 210 can obtain medium-temperature and medium-pressure refrigerant to enter the flash evaporator 810 to meet the flash pressure required for the operation of the flash evaporator 810, and obtain medium-temperature and medium-pressure gaseous refrigerant for replenishing air in the two-stage compressor; the second throttling device 220 can obtain low-temperature and low-pressure refrigerant to meet the temperature and pressure requirements on the evaporator 300 side, and realize the refrigeration effect of the refrigerant in the evaporator 300.

[0052] Wherein, the structure of at least one of the first throttling device 210 and the second throttling device 220 is as follows: Figure 2 As shown, at least one of the first throttling device 210 and the second throttling device 220 includes a rotating shaft 201, a first shell 202, an expansion wheel 203, a second shell 206 and a compression wheel 207. The first throttling device 210 and the second throttling device 220 can be selectively energy-recovered and reused as needed. For example, only the first throttling device 210 or the second throttling device 220 can be energy-recovered and reused, or both the first throttling device 210 and the second throttling device 220 can be energy-recovered and reused.

[0053] Alternatively, if Figure 2-4 As shown, the first throttling device 210 includes a rotating shaft 201, a first shell 202 and an expansion wheel 203 disposed in the first shell 202. The rotating shaft 201 is coaxially fixedly connected with the expansion wheel 203. The first shell 202 is provided with a first inlet 204 and a first outlet 205. The first inlet 204 is connected to the condenser 100 through a pipeline. After the high-pressure liquid refrigerant flowing out of the condenser 100 enters the first shell 202 through the first inlet 204, it pushes the expansion wheel 203 to rotate and do work, and then becomes a medium-temperature and medium-pressure refrigerant, and then is discharged from the first outlet 205. The first outlet 205 is connected to the liquid inlet of the flasher 810. In this process, the rotating shaft 201 will rotate synchronously with the expansion wheel 203. The first throttling device 210 realizes throttling and reducing the pressure of the refrigerant while converting the energy into kinetic energy that is conducive to utilization, thereby realizing energy recovery during the throttling process. In order to realize the utilization of the energy recovered by the first throttling device 210 during the throttling process, as Figure 2-4 As shown, the first throttling device 210 also includes a second shell 206 and a compression wheel 207 arranged in the second shell 206. The rotating shaft 201 is coaxially fixedly connected with the compression wheel 207. The second shell 206 is provided with a second inlet 208 and a second outlet 209. The refrigerant discharged from the evaporator 300 enters the second shell 206 through the second inlet 208, is compressed by the compression wheel 207, and is discharged from the second outlet 209. The relatively high-pressure gas in the first throttling device 210 drives the expansion wheel 203 to operate, and then drives the compression wheel 207 to rotate through the rotating shaft 201, so that the compression wheel 207 sucks in the gaseous refrigerant through the second inlet 208 and compresses it to do work, thereby increasing the pressure of the gaseous refrigerant. After being discharged, it will enter the gas-liquid separator 400, and the gaseous refrigerant will be sucked away and compressed by the compressor 500 again and then enter the condenser 100. Due to the work done by the compression wheel 207, the suction pressure of the compressor 500 is increased, the power consumption of the compressor 500 is reduced, and the reuse of the energy recovered during the throttling process of the first throttling device 210 is realized.

[0054] Alternatively, if Figure 2-4As shown, the second throttling device 220 includes a rotating shaft 201, a first shell 202, and an expansion wheel 203 disposed in the first shell 202. The rotating shaft 201 is coaxially fixedly connected with the expansion wheel 203. The first shell 202 is provided with a first inlet 204 and a first outlet 205. The first inlet 204 is connected to the liquid outlet of the flash evaporator 810 through a pipeline. After the medium-temperature and medium-pressure refrigerant flowing out of the flash evaporator 810 enters the first shell 202 through the first inlet 204, it pushes the expansion wheel 203 to rotate and do work, and then becomes a low-temperature and low-pressure refrigerant, and then is discharged from the first outlet 205. The first outlet 205 is connected to the evaporator 300. In this process, the rotating shaft 201 will rotate synchronously with the expansion wheel 203. The second throttling device 220 realizes throttling and reducing the pressure of the refrigerant while converting the energy into kinetic energy that is easily utilized, thereby realizing energy recovery during the throttling process. In order to further realize the utilization of the energy recovered by the second throttling device 220 during the throttling process, as shown Figure 2-4 As shown, the second throttling device 220 includes a second shell 206 and a compression wheel 207 arranged in the second shell 206, the rotating shaft 201 is coaxially fixedly connected with the compression wheel 207, and the second shell 206 is provided with a second inlet 208 and a second outlet 209. The refrigerant discharged from the evaporator 300 enters the second shell 206 through the second inlet 208, is compressed by the compression wheel 207, and is discharged from the second outlet 209. The compression wheel 207 is used as a compression wheel. The relatively high-pressure gas in the second throttling device 220 drives the expansion wheel 203 to operate, and then drives the compression wheel 207 to rotate through the rotating shaft 201, so that the compression wheel 207 sucks in the gaseous refrigerant through the second inlet 208 and compresses it to do work, thereby increasing the pressure of the gaseous refrigerant. After being discharged, it will enter the gas-liquid separator 400, and the gaseous refrigerant will be sucked away and compressed by the compressor 500 again and enter the condenser 100. Due to the work done by the compression wheel 207, the suction pressure of the compressor 500 is increased, and the power consumption of the compressor 500 is reduced, thereby realizing the reuse of energy recovered during the throttling process of the second throttling device 220.

[0055] In some embodiments, the first throttling device 210 and the second throttling device 220 are both as follows Figure 2 The structure shown in the figure, that is, the first throttling device 210 and the second throttling device 220 both include a rotating shaft 201, a first housing 202, an expansion wheel 203, a second housing 206 and a compression wheel 207. Figure 3 and 8As shown, the second inlet 208 of the first throttling device 210 and the second inlet 208 of the second throttling device 220 are both connected to the evaporator 300, and the second outlet 209 of the first throttling device 210 and the second outlet 209 of the second throttling device 220 are both connected to the gas-liquid separator 400. At this time, the refrigerant flowing out of the evaporator 300 is divided into two parallel paths and flows into the second inlet 208 of the first throttling device 210 and the second inlet 208 of the second throttling device 220 respectively. After being compressed in the first throttling device 210 and the second throttling device 220 respectively, they are gathered into the gas-liquid separator 400. At this time, the flow rate of the compressed refrigerant can be effectively increased, which is suitable for the working scene of large flow compression.

[0056] In some embodiments, the first throttling device 210 and the second throttling device 220 are both as follows Figure 2 The structure shown in the figure, that is, the first throttling device 210 and the second throttling device 220 both include a rotating shaft 201, a first housing 202, an expansion wheel 203, a second housing 206 and a compression wheel 207. Figure 4 and 9 As shown, the second inlet 208 of the second throttling device 220 is connected to the evaporator 300 , the second outlet 209 of the second throttling device 220 is connected to the second inlet 208 of the first throttling device 210 , and the second outlet 209 of the first throttling device 210 is connected to the gas-liquid separator 400 . At this time, the refrigerant flowing out of the evaporator 300 first flows into the second inlet 208 of the second throttling device 220, is compressed by the compression wheel 207 of the second throttling device 220, and flows out from the second outlet 209 of the second throttling device 220, and then continues to pass through the second inlet 208 of the first throttling device 210 to enter the second shell 206 of the first throttling device 210, and then is compressed by the compression wheel 207 of the first throttling device 210 and discharged from the second outlet 209 of the first throttling device 210 to the gas-liquid separator 400. By connecting the second throttling device 220 and the compression part of the first throttling device 210 in series, the two-stage compression of the gaseous refrigerant flowing out of the evaporator 300 is realized. At this time, the pressure head of the compressed refrigerant can be effectively improved, which is suitable for working scenarios with large pressure head compression.

[0057] In some embodiments, Figure 2 As shown, the rotating shaft 201 is supported by a gas bearing 211. The only lubricant used by the gas bearing 211 is air, which has no adverse effect on the environment and can be applied to the working environment of the pollution-free refrigeration unit. The gas bearing 211 can be further selected as a static pressure gas bearing or a dynamic pressure gas bearing. For the refrigeration unit of the present application, the power end of the rotating shaft 201 runs on the high-pressure side of the refrigeration system, and the turbine speed is relatively high, and it is preferably supported by a dynamic pressure gas bearing.

[0058] In the above embodiment, as the working process continues to run, the liquid in the gas-liquid separator 400 will continue to accumulate. If no method is found to lead it away, the compressor 500 will inhale liquid, causing damage to the compressor 500. Based on this, a drain pipe is connected to the drain port of the gas-liquid separator 400 to discharge the liquid in the gas-liquid separator 400, so as to maintain the liquid level in the gas-liquid separator 400 within a normal range and avoid the compressor 500 inhaling liquid. Optionally, the drain port of the gas-liquid separator 400 is connected to the evaporator 300 through a drain pipe. The liquid in the gas-liquid separator 400 can be led out in time through the drain pipe and the control valve thereon, so that it enters the evaporator for suction heat exchange and returns to the refrigerant circulation system. In order to make this part of the liquid refrigerant meet the working pressure requirements on the evaporator 300 side, a throttling element needs to be set on the drain pipe to throttle and reduce the pressure of this part of the liquid refrigerant.

[0059] In the above refrigeration circuit, when the refrigeration unit is working, the power consumed by the compressor 500 is mainly used to increase the refrigerant pressure. However, since the compressor 500 inevitably generates heat when working, and the electrical components of the controller 600 used to control the refrigeration unit will also heat up, it is necessary to use a liquid refrigerant with a relatively low temperature to cool down. Traditional cooling methods such as Figure 5 As shown in (taking a two-stage compressor system as an example), the high pressure of the condenser is used to transport the liquid refrigerant in it to the cooling system of the compressor's motor and controller for heat exchange and cooling, and the refrigerant that needs to enter the evaporator to exert a cooling effect is diverted out to cool the heating area. This part of the energy is generated after the compressor compresses and works, which is actually equivalent to consuming part of the power of the compressor, increasing the power consumption of the unit and reducing the energy efficiency of the unit. Based on this, the refrigeration unit of the present application also includes a cooling circuit, and the cooling circuit includes a driving component and a cooling pipeline. The cooling pipeline is configured to exchange heat with the part to be dissipated, and the driving component is configured to drive the liquid in the gas-liquid separator to flow in the cooling circuit. When the discharge port of the gas-liquid separator 400 is connected to the evaporator 300 through a discharge pipeline, a throttling element needs to be provided on the discharge pipeline in order to make this part of the liquid refrigerant meet the working pressure requirement on the evaporator 300 side. A part of the energy will also be dissipated during the throttling process. By using driving components and cooling pipelines, the liquid accumulated in the gas-liquid separator 400 can be used to cool the heating areas in the system, and the energy recovered by the throttling device 200 can also be partially used to drive the refrigerant to flow in the cooling pipeline, thereby reducing the energy consumption of the driving components.

[0060] The driving component can be specifically selected as an ejector 710. Figure 6 and 7As shown, taking a refrigeration unit with a single-stage compressor as an example, the cooling circuit of the refrigeration unit of the embodiment of the present application mainly includes an ejector 710, a high-pressure pipeline 720, a low-pressure pipeline 730 and a cooling pipeline 740, wherein the ejector flow inlet 711 of the ejector 710 is connected to the condenser 100 through the high-pressure pipeline 720, the outlet 712 of the ejector 710 is connected to the evaporator 300 through the low-pressure pipeline 730, one end of the cooling pipeline 740 is connected to the liquid outlet of the gas-liquid separator 400, and the other end is connected to the ejected flow inlet 713 of the ejector 710, and the cooling pipeline 740 is configured to perform heat exchange with the part to be dissipated. During normal operation of the unit, the high-pressure liquid refrigerant fluid in the condenser 100 is sprayed into the ejector 710 through the high-pressure pipeline 720 and the ejection flow inlet 711 of the ejector 710, and a pressure difference is formed inside and outside the ejector 710. At this time, under the action of the pressure difference, the low-temperature liquid refrigerant in the gas-liquid separator 400 will be sucked into the ejector 710 through the cooling pipeline 740 and the ejection flow inlet 713 as the ejection fluid, and then mixed with the refrigerant sprayed from the ejection flow inlet 711 in the ejector 710, and then the pressure is restored by pressure expansion to reach the specified pressure, and the refrigerant fluid is discharged from the outlet 712 and sent to the evaporator 300. In this process, the process of the high-pressure refrigerant of the condenser 100 passing through the ejector 710 is actually a process of throttling, reducing pressure and cooling, and can be directly sent to the evaporator 300 for use after the pressure is reduced. At the same time, the ejector 710 can be used to recover the pressure energy on the high-pressure side of the condenser 100 and convert it into kinetic energy. The bottom liquid refrigerant in the gas-liquid separator 400 flows under the driving force of the kinetic energy, and is transported to the area to be cooled through the cooling pipeline 740 for cooling, and finally enters the ejector 710. In this process, since the compressor 500 does not work on the refrigerant in the cooling circuit, it only recycles and utilizes the pressure energy in the throttling process of the ejector 710 as a driving force, and obtains low-temperature refrigerant from the gas-liquid separator 400 for cooling, which reduces the power consumption of the compressor 500, improves the energy efficiency level of the refrigeration unit, and achieves energy saving of the unit.

[0061] In some embodiments, the heat dissipation part includes the motor and controller 600 of the compressor 500, and the cooling pipeline 740 is sequentially connected in series with the motor and the controller 600. Specifically, the motor and the controller 600 of the compressor 500 have their own cooling systems, and the cooling pipeline 740 is sequentially connected in series with the cooling system of the motor and the cooling system of the controller 600. The ejected fluid comes from the gas-liquid separator 400, and the liquid flows through the motor and the controller 600 of the compressor 500 in sequence, and then enters the ejector 710 through the cooling pipeline 740, and finally enters the evaporator 300, so that the motor and the controller 600 are cooled without consuming additional power of the compressor 500, thereby improving the energy efficiency of the unit.

[0062] like Figure 7 As shown, a specific embodiment of the ejector 710 is given. The ejector 710 mainly includes an ejector 714 and a shell 715. The shell 715 is formed with a receiving chamber 716, a mixing chamber 717 and a diffusion chamber 718 in sequence. The nozzle of the ejector 714 extends into the receiving chamber 716. The ejection flow inlet 711 is arranged on the ejector 714, and the ejected flow inlet 713 is connected with the receiving chamber. The receiving chamber 716 gradually contracts in diameter in the direction close to the mixing chamber 717 to form a conical structure. The mixing chamber 717 is a cylindrical chamber. The diffusion chamber 718 gradually expands in diameter in the direction away from the mixing chamber 717 to form a conical structure. The high-pressure liquid refrigerant fluid in the condenser 100 enters the flow channel inside the ejector 714 through the ejection flow inlet 711. The flow channel in the ejector 714 is a contraction flow channel. When the high-pressure fluid is contraction-circulated to the nozzle position of the ejector 714, the flow velocity reaches the maximum and is ejected from the nozzle into the receiving chamber 716. The high-speed ejected fluid forms a negative pressure zone in the receiving chamber 716. At this time, under the action of the pressure difference, the liquid refrigerant in the gas-liquid separator 400 enters the receiving chamber 716 through the ejected fluid inlet 713 as the ejected fluid, and then mixes evenly with the fluid ejected from the ejection part 714 in the mixing chamber 717, and then recovers the pressure through the diffusion chamber 718 to reach the specified pressure and flows out from the outlet 712 to send the fluid to the evaporator 300. The ejected fluid comes from the gas-liquid separator 400, and the liquid flows through the motor and controller 600 of the compressor 500 in sequence, enters the mixing chamber 717 of the ejector 710 through the cooling circuit, and finally enters the evaporator 300. In the structure of the ejector 710, the high-pressure fluid is accelerated and depressurized by the ejector 714, a negative pressure area is formed in the chamber to obtain pressure energy that can be converted and utilized, and then the refrigerant fluid is decelerated and pressurized to the pressure value required by the evaporator 300 side in the expansion chamber 718, so that the refrigerant fluid can be further used for refrigeration in the evaporator 300 after flowing out of the ejector 710, so that only the pressure energy of the high-pressure fluid flowing out of the condenser 100 is recovered without dissipating the refrigeration effect of the refrigerant in the evaporator 300. Preferably, the ejector 710 also includes an adjustment needle 719, which is connected to the ejector 714 to adjust the fluid flow in the ejector 714. Specifically, the adjustment needle 719 is screwed on the injection part 714 and extends into the flow channel in the injection part 714. By rotating the adjustment needle 719, the amount of rotation of the adjustment needle 719 in the injection part 714 can be achieved, and then the distance between the end of the adjustment needle 719 and the nozzle of the injection part 714 can be adjusted, thereby changing the flow area of ​​the flow channel in the injection part 714, thereby achieving flow regulation of the refrigerant fluid under different working conditions.

[0063] like Figure 8 and 9As shown, the cooling circuit in the above embodiment is also applicable to the refrigeration unit of the two-stage compressor, and the cooling circuit provided in the embodiment of the present application can be used in conjunction with the new throttling device. Figure 6 As shown, the structural arrangement relationship of the throttling device 200 and the cooling circuit in the refrigeration unit of the single-stage compressor is given; Figure 8 As shown, the structural arrangement relationship of the first throttling device 210, the second throttling device 220 and the cooling circuit in the refrigeration unit of the two-stage compressor is given, wherein the compression part of the first throttling device 210 and the compression part of the second throttling device 220 are used in parallel; Fig. 9 As shown, the structural arrangement relationship of the first throttling device 210, the second throttling device 220 and the cooling circuit in the refrigeration unit of the two-stage compressor is given, wherein the compression part of the first throttling device 210 is used in series with the compression part of the second throttling device 220. It should be noted that when the compressor 500 is a two-stage compressor, the cooling pipeline 740 can be divided into two parallel branches, which are respectively used to cool the motors of the two compression sections of the two-stage compressor, and the two parallel branches are combined and then connected in series with the controller 600.

[0064] It should be noted that in Figure 6 , Figure 8 and Fig. 9 In the refrigeration unit shown, the throttling device 200 (first throttling device 210, second throttling device 220), gas-liquid separator 400 and cooling circuit provided in the embodiment of the present application work in coordination with each other. Figure 8 and Fig. 9Take the refrigeration unit as an example to illustrate, on the one hand, after the gaseous refrigerant flowing out of the evaporator 300 is compressed by the compression wheel 207 of the first throttling device 210 and the second throttling device 220, there will be pressure loss and heat release in the flow process, so that liquid will be produced. Then the main purpose of this part of the refrigerant entering the gas-liquid separator 400 is to separate the liquid and gas in the refrigerant to achieve normal air intake of the compressor 500. As the working process continues to run, the liquid in the gas-liquid separator 400 continues to accumulate. If no method is found to lead it away, the compressor 500 will inhale liquid, causing damage to the compressor 500. Therefore, the pressure energy recovered by the ejector 710 in the cooling circuit can timely lead the liquid in the gas-liquid separator 400 and circulate in the cooling circuit. loop, realizing cooling down of the heating area while maintaining the liquid level in the gas-liquid separator 400 within a normal range, avoiding liquid inhalation by the compressor 500; secondly, the gaseous refrigerant flowing out of the evaporator 300 has a relatively high pressure head after being compressed by the compression wheel 207 of the first throttling device 210 and the second throttling device 220. After the gas enters the gas-liquid separator 400, the internal working pressure is increased, which is more conducive to the liquid phase in the gas-liquid separator 400 being drained by the ejector 710. The ejection effect of the ejector 710 will be better, that is, the energy recovered by the first throttling device 210 and the second throttling device 220 can not only increase the suction pressure of the compressor 500 and reduce the power consumption of the compressor 500, but will also be partially used to drive the refrigerant circulation in the cooling circuit.

[0065] like Fig.10 As shown, the schematic diagram shows Figure 8 The pressure-enthalpy diagram of part of the cycle process in the refrigeration unit shown in the figure, the original compressor directly sucks air from the evaporator to the condenser pressure without passing through the compression part of the throttling device, and its compression work is as follows Figure 8 The sum of the black shadow and the red shadow. Figure 8 The refrigeration unit shown in the figure compresses the pressure of the evaporator to the pressure corresponding to the gas-liquid separator through energy recovery. The compressor compresses the suction air from the gas-liquid separator to the pressure corresponding to the condenser. The compression work is mainly the red shaded part, that is, Figure 8 The black shaded area in the graph is the recovery work.

[0066] The refrigeration unit with energy recovery function provided in the embodiment of the present application, on the one hand, guides the high-pressure refrigerant to the ejector 710 through the high-pressure pipeline 720, and the refrigerant after throttling and cooling through the ejector 710 is sent back to the evaporator 300. The ejector 710 recovers the pressure energy on the high-pressure side in the above process, and uses it to transport the liquid refrigerant to the heating areas such as the electrical components of the motor and the controller 600 for cooling, thereby realizing the cooling and energy saving effect of the unit by energy recovery; on the other hand, the throttling device of the new structure is used to recover the kinetic energy converted by the work of the high-pressure side refrigerator, compress the gaseous refrigerant to increase the pressure of the gaseous refrigerant, increase the suction pressure of the compressor 500, and reduce the power consumption of the compressor 500.

[0067] Some embodiments in this specification are described in a progressive or parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0068] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A refrigeration unit, characterized in that: The refrigeration circuit of the refrigeration unit includes a condenser, a throttling device, an evaporator and a compressor connected by pipelines; The throttling device comprises a rotating shaft, a first shell and an expansion wheel arranged in the first shell, the rotating shaft is coaxially fixedly connected with the expansion wheel, the first shell is provided with a first inlet and a first outlet, after the refrigerant enters the first shell through the first inlet, it drives the expansion wheel to rotate and do work, and then is discharged from the first outlet; The throttling device also includes a second shell and a compression wheel arranged in the second shell. The rotating shaft is coaxially and fixedly connected to the compression wheel. The second shell is provided with a second inlet and a second outlet. The refrigerant discharged from the evaporator enters the second shell through the second inlet, is compressed by the compression wheel and is discharged from the second outlet.

2. The refrigeration unit according to claim 1, characterized in that: The refrigeration unit further includes a gas-liquid separator configured to receive the refrigerant discharged from the second outlet and supply gaseous refrigerant to the compressor.

3. The refrigeration unit according to claim 2, characterized in that: The compressor is a two-stage compressor, and the refrigeration circuit further includes a flasher, which is arranged between the condenser and the evaporator. An air supply branch is provided between the exhaust port of the flasher and the air supply port of the two-stage compressor.

4. The refrigeration unit according to claim 3, characterized in that: The throttling device includes a first throttling device and a second throttling device, wherein the first throttling device is disposed between the condenser and the flasher, and the second throttling device is disposed between the flasher and the evaporator.

5. The refrigeration unit according to claim 4, characterized in that: At least one of the first throttling device and the second throttling device includes the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel.

6. The refrigeration unit according to claim 4, characterized in that: The first throttling device and the second throttling device both include the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel. The second inlet of the first throttling device and the second inlet of the second throttling device are both connected to the evaporator, and the second outlet of the first throttling device and the second outlet of the second throttling device are both connected to the gas-liquid separator.

7. The refrigeration unit according to claim 4, characterized in that: The first throttling device and the second throttling device both include the rotating shaft, the first shell, the expansion wheel, the second shell and the compression wheel. The second inlet of the second throttling device is connected to the evaporator, the second outlet of the second throttling device is connected to the second inlet of the first throttling device, and the second outlet of the first throttling device is connected to the gas-liquid separator.

8. The refrigeration unit according to any one of claims 2 to 7, characterized in that: The liquid discharge port of the gas-liquid separator is communicated with the evaporator through a liquid discharge pipeline.

9. The refrigeration unit according to any one of claims 2 to 7, characterized in that: The refrigeration unit also includes a cooling circuit, which includes a driving component and a cooling pipeline. The cooling pipeline is configured to perform heat exchange with a part to be cooled. The driving component is configured to drive the liquid in the gas-liquid separator to flow in the cooling circuit.

10. The refrigeration unit according to claim 1, characterized in that: The rotating shaft is supported by a gas bearing.

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