Compressor cooling structure, refrigeration system, air conditioner and control method

Abstract

The present invention discloses a compressor cooling structure, a refrigeration system, an air conditioner and a control method, which belong to the field of compressor cooling; they are applied to a multi-compressor refrigeration cycle loop, and the cooling pipeline provides low-temperature refrigerant for the compressor, and the refrigerant returns to the evaporator through the return air pipeline after cooling the compressor. The ejector inlet in the cooling pipeline is connected to the condenser, and the refrigerant can be obtained from the condenser. The ejector port is connected to the evaporator, and the outlet is connected to the compressor through an electronic expansion valve. When the unit is running at a high pressure ratio, the ejector mixes the low-pressure refrigerant of the evaporator with the high-pressure refrigerant of the evaporator to reduce the refrigerant pressure. Since the refrigerant temperature changes in direct proportion to the refrigerant pressure, the refrigerant temperature can be reduced to ensure that the ejector outlet can provide low-temperature refrigerant to the compressor. In this way, at a high pressure ratio, the ejector inlet and outlet of the cooling pipeline can also provide low-temperature refrigerant, which ensures the cooling effect of the cooling pipeline and the reliable operation of the unit.

Description

Technical Field

[0001] The present invention relates to the field of compressor cooling, and in particular to a compressor cooling structure, a refrigeration system, an air conditioner and a control method. Background Art

[0002] Most of the current refrigeration system units use a single compressor, whether single-stage compression or double-stage compression. This solution is more suitable for refrigeration or heating conditions with a relatively small pressure ratio P0 (condensing pressure / evaporation pressure). However, with the increasing demand for high-pressure ratio conditions in the market, such as some ultra-high temperature heat pumps operating at high outlet water temperatures, it is difficult for a single compressor unit to meet such conditions. Therefore, dual-compressor or multi-compressor multi-stage compression refrigeration systems are more widely used in units to meet various refrigeration and heating needs in the market.

[0003] Large refrigeration units generate a lot of heat during operation. If they are not cooled in time, the heat accumulation will cause the temperature of the internal winding of the compressor to rise, and in severe cases, the compressor will burn out. At present, most chillers use the following cooling method: liquid refrigerant is taken from one side of the condenser, throttled, enters the compressor cavity to gasify and cool the compressor, and then returns to the evaporator from the compressor cavity. For conventional chillers, this method can achieve good results, but for dual compressor refrigeration systems with high compression ratios, it is difficult to ensure the cooling effect of the compressor.

[0004] For the dual compressor refrigeration system, the heat generation is greater. Under the high pressure ratio condition, the temperature of the condenser refrigerant liquid is very high. The conventional compressor cooling method cannot fully cool the compressor and cannot ensure the safe and reliable operation of the unit. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a compressor cooling structure, a refrigeration system, an air conditioner and a control method to solve the problem that under high pressure ratio conditions, the temperature of the condenser refrigerant liquid is very high, and the conventional compressor cooling method cannot fully cool the compressor and cannot ensure the safe and reliable operation of the unit.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] In a first aspect, a compressor cooling structure is provided, which is applied to a multi-compressor refrigeration cycle loop, wherein all compressors in the multi-compressor refrigeration cycle loop are connected in series, including a cooling pipeline and a return air pipeline;

[0008] The cooling pipeline includes an ejector and an electronic expansion valve;

[0009] The inlet of the ejector is connected to the condenser of the multi-compressor refrigeration cycle, the ejection port is connected to the evaporator of the multi-compressor refrigeration cycle, and the outlet of the ejector is respectively connected to each compressor of the multi-compressor refrigeration cycle through the electronic expansion valve to provide liquid refrigerant for each compressor;

[0010] One end of the return air pipeline is connected to the compressor, and the other end is connected to the evaporator, so as to transport the refrigerant vaporized in the compressor to the evaporator.

[0011] Furthermore, it also includes a controller, and an electromagnetic valve is arranged between the ejection port of the ejector and the evaporator; the electromagnetic valve is electrically connected to the controller, and when the difference between the pressure at the condenser and the pressure at the evaporator is greater than a first preset value, the controller controls the electromagnetic valve to open; when the difference between the pressure at the condenser and the pressure at the evaporator is less than a second preset value, the controller controls the electromagnetic valve to disconnect.

[0012] Furthermore, the cooling pipeline includes a first cooling pipeline, and an outlet of a first ejector in the first cooling pipeline is respectively connected to each compressor of the multi-compressor refrigeration cycle through a first electronic expansion valve.

[0013] Furthermore, the first electronic expansion valve is connected to the controller so that the controller controls the opening of the first electronic expansion valve according to the real-time power of the unit where the multi-compressor refrigeration cycle loop is located.

[0014] Furthermore, the cooling pipeline includes a second cooling pipeline, and an independent electronic expansion valve is arranged between the outlet of the second ejector in the second cooling pipeline and each compressor of the multi-compressor refrigeration cycle loop.

[0015] Further, the independent electronic expansion valve is connected to the controller so that the controller controls the opening of the independent electronic expansion valve according to the winding temperature of the compressor to which the independent electronic expansion valve is connected.

[0016] Furthermore, an independent solenoid valve is provided between the outlet of the second ejector and each compressor of the multi-compressor refrigeration cycle circuit, and the independent solenoid valve is connected to the controller. When the compressor connected to the independent solenoid valve is started, the controller controls the independent solenoid valve to open; when the compressor connected to the independent solenoid valve is stopped, the controller controls the independent solenoid valve to close.

[0017] Furthermore, a throttling orifice plate is provided at the outlet of the ejector.

[0018] In a second aspect, a refrigeration system is provided, comprising a structure described in any one of the technical solutions provided in the first aspect.

[0019] In a third aspect, an air conditioner is provided, comprising the refrigeration system in the technical solution provided in the second aspect.

[0020] In a fourth aspect, a compressor cooling control method is provided, which is applied to the refrigeration system in the technical solution provided in the second aspect, and the control method comprises the following steps:

[0021] Obtain parameters in multiple refrigeration cycle loops;

[0022] The components of the refrigeration system are controlled according to the parameters.

[0023] Further, the parameters include the operation status of the compressor, and the components of the refrigeration system controlled according to the parameters include:

[0024] When a start command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling line is controlled to open;

[0025] When a stop command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling pipeline is controlled to close after a delay of a preset time.

[0026] Further, the parameter includes a compressor winding temperature, and the components of the refrigeration system are controlled according to the parameter, including:

[0027] When the compressor is running, the opening degree of the independent electronic expansion valve corresponding to the compressor is controlled according to the winding temperature.

[0028] Further, the parameter includes a difference between a condenser pressure and an evaporator pressure, and the components of the refrigeration system are controlled according to the parameter, including:

[0029] When the difference is greater than a first preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to open;

[0030] When the difference is less than a second preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to be closed.

[0031] Furthermore, the parameters include the real-time power of the unit where the refrigeration system is located, and the components of the refrigeration system are controlled according to the parameters, including:

[0032] The opening degree of the first electronic expansion valve in the first cooling pipeline is controlled according to the real-time power.

[0033] Beneficial effects:

[0034] The technical solution of the present application provides a compressor cooling structure, a refrigeration system, an air conditioner and a control method, which are applied to a multi-compressor refrigeration cycle circuit, including a cooling pipeline and a return air pipeline; the cooling pipeline provides low-temperature refrigerant for the compressor, and the refrigerant returns to the evaporator through the return air pipeline after cooling the compressor. The ejector inlet in the cooling pipeline is connected to the condenser, and the refrigerant can be obtained from the condenser. The ejector port is connected to the evaporator, and the outlet is connected to the compressor through an electronic expansion valve. When the unit is running at a high pressure ratio, the ejector mixes the low-pressure refrigerant of the evaporator with the high-pressure refrigerant of the evaporator to reduce the refrigerant pressure. Since the refrigerant temperature changes in direct proportion to the refrigerant pressure, the refrigerant temperature can be reduced to ensure that the ejector outlet can provide low-temperature refrigerant to the compressor. In this way, at a high pressure ratio, the ejector inlet and outlet of the cooling pipeline can also provide low-temperature refrigerant, which ensures the cooling effect of the cooling pipeline and the reliable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 is a schematic diagram of a compressor cooling structure provided by an embodiment of the present invention;

[0037] Figure 2 1 is a schematic diagram of a compressor cooling structure applied to a dual compressor refrigeration cycle provided by an embodiment of the present invention;

[0038] Figure 3 It is a flow chart of a compressor cooling control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0040] It should be noted that a multi-compressor refrigeration cycle circuit is a plurality of compressors connected in series, taking a dual-compressor refrigeration cycle circuit as an example; Figure 1As shown, the dual compressor refrigeration cycle includes a first compressor M1 and a second compressor M2 connected in series, the second compressor M2 is connected to the condenser 1, the condenser 1 is connected to the evaporator 2 through the throttling device 3, and the evaporator 2 is connected to the first compressor M1.

[0041] In the first embodiment, the present invention provides a compressor cooling structure for use in a multi-compressor refrigeration cycle loop, in which all compressors in the multi-compressor refrigeration cycle loop are connected in series. Figure 1 , Figure 1 A dual compressor refrigeration cycle is used for illustration, including a cooling line and a return air line 4;

[0042] The cooling pipeline includes an ejector 5 and an electronic expansion valve 6;

[0043] The inlet of the ejector 5 is connected to the condenser 1 of the multi-compressor refrigeration cycle loop, the ejection port is connected to the evaporator 2 of the multi-compressor refrigeration cycle loop, and the outlet of the ejector 5 is respectively connected to each compressor of the multi-compressor refrigeration cycle loop through the electronic expansion valve 7 to provide liquid refrigerant for each compressor;

[0044] One end of the return air pipeline 4 is connected to the compressor, and the other end is connected to the evaporator 2 so as to transport the refrigerant vaporized in the compressor to the evaporator 2 .

[0045] The compressor cooling structure provided by the embodiment of the present invention is applied to a multi-compressor refrigeration cycle circuit, including a cooling pipeline and a return air pipeline; the cooling pipeline provides low-temperature refrigerant for the compressor, and the refrigerant returns to the evaporator through the return air pipeline after cooling the compressor. The ejector inlet in the cooling pipeline is connected to the condenser, and the refrigerant can be obtained from the condenser. The ejector port is connected to the evaporator, and the outlet is connected to the compressor through an electronic expansion valve. When the unit is operating at a high pressure ratio, the ejector mixes the low-pressure refrigerant of the evaporator with the high-pressure refrigerant of the evaporator to reduce the refrigerant pressure. Since the refrigerant temperature changes in direct proportion to the refrigerant pressure, the refrigerant temperature can be reduced to ensure that the ejector outlet can provide low-temperature refrigerant to the compressor. In this way, at a high pressure ratio, the ejector inlet and outlet of the cooling pipeline can also provide low-temperature refrigerant, which ensures the cooling effect of the cooling pipeline and the reliable operation of the unit.

[0046] In the second embodiment, the present invention takes a dual compressor refrigeration cycle structure as an example to provide a specific compressor cooling structure, including a first cooling pipeline and a second cooling pipeline.

[0047] The first cooling pipeline: the liquid inlets of the condenser 1 and the evaporator 2 are respectively connected to the inlet and the injection port of the first ejector 51 through pipelines, and a third solenoid valve SV3 is connected in series between the injection port and the evaporator 2. The opening and closing of the third solenoid valve SV3 is automatically controlled by reading the pressure difference (condensing pressure - evaporating pressure) of the refrigeration unit. When the pressure difference is small, the controller closes the third solenoid valve SV3 to ensure the inlet and outlet pressure difference of the cooling pipeline and the cooling effect of the cooling pipeline. When the pressure difference is large, the controller controls the third solenoid valve SV3 to open to ensure the inlet and outlet pressure difference of the cooling pipeline and the cooling effect of the cooling pipeline. The ejector outlet is connected in series with a first throttling orifice 8 and a first electronic expansion valve EXV1 through a pipeline. The aperture of the throttling orifice is calculated according to the cooling capacity required for cooling the compressor in the design working condition. The first electronic expansion valve EXV1 controls its opening by reading the real-time power rate of the unit, thereby controlling the amount of refrigerant, automatically adapting to the cooling requirements under different working conditions, and then dividing into two branches to enter the first compressor M1 and the second compressor M2 respectively; after the liquid refrigerant enters the compressor cavity, it is vaporized in the compressor cavity to cool the compressor, and then returns to the evaporator 2 through the return air pipeline.

[0048] The second cooling pipeline: the liquid inlets of the condenser 1 and the evaporator 2 are respectively connected to the inlet and the injection port of the second ejector 52 through pipelines, and a fourth solenoid valve SV4 is connected in series between the injection port and the evaporator 2. The opening and closing of the fourth solenoid valve SV4 is automatically controlled by reading the pressure difference (condensing pressure - evaporating pressure) of the refrigeration unit. When the pressure difference is small, the controller closes the solenoid valve to ensure the inlet and outlet pressure difference of the cooling pipeline and the cooling effect of the cooling pipeline. When the pressure difference is large, the controller controls the third solenoid valve SV3 to open to ensure the inlet and outlet pressure difference of the cooling pipeline and the cooling effect of the cooling pipeline. After the liquid comes out of the ejector, it passes through a second throttling orifice plate 9 and is divided into two branches. The aperture of the throttling orifice plate is calculated according to the cooling capacity required for cooling the compressor under the design working conditions. The branch where the first compressor M1 is located is connected in series with a first solenoid valve SV1 and a second electronic expansion valve EXV2, and the branch where the second compressor M2 is located is connected in series with a second solenoid valve SV2 and a third electronic expansion valve EXV3. The opening and closing of the first solenoid valve SV1 and the second solenoid valve SV2 are controlled by whether the corresponding compressor is started or not. When the compressor is started, the solenoid valve of the corresponding branch is opened; when the compressor is stopped, the solenoid valve of the corresponding branch is closed. The opening of the second electronic expansion valve EXV2 and the third electronic expansion valve EXV3 is controlled by reading the internal winding temperature of the compressor of the corresponding branch compressor. The liquid refrigerant finally enters the compressor cavity, and after being vaporized in the compressor cavity to cool the compressor, it returns to the evaporator 2 through the return air pipeline.

[0049] The specific compressor cooling structure provided by the embodiment of the present invention has two cooling pipelines that both control the opening and closing of the solenoid valve by detecting the evaporation and condensation pressure difference and adopt injection to take liquid. The inlet on one side of the ejector is connected to the condenser liquid taking bag, and the inlet on the other side is connected to the evaporator liquid taking bag. A solenoid valve is connected in series on the pipeline connected to the evaporator, and the outlet is connected to the cooling pipeline. By injecting liquid, liquid refrigerant with a lower temperature can still be obtained under high-temperature heat pump conditions to ensure the cooling effect. In combination with a suitable throttling orifice plate, the throttling loss can be reduced and the energy efficiency of the unit can be improved.

[0050] In the third embodiment, the present invention provides a refrigeration system, including the compressor cooling structure provided by the first embodiment or the second embodiment. In the refrigeration system provided by the embodiment of the present invention, the two cooling paths are controlled by different parameters respectively, and the two paths are connected in parallel, and can be opened and adjusted at the same time. One cooling path is connected in series with a throttling orifice plate and an electronic expansion valve, and then divided into two cooling pipelines connected to different compressor compressor chambers. The opening of the electronic expansion valve is automatically adjusted according to the real-time power rate of the unit through a certain control logic; the other cooling pipeline is connected to a throttling orifice plate, and then divided into two paths, each of which is connected in series with a solenoid valve and an electronic expansion valve, and the electronic expansion valve controls its opening through control logic according to the compressor winding temperature. Both cooling pipelines control the opening and closing of the solenoid valve by detecting the evaporation and condensation pressure difference and adopt the method of liquid extraction by injection. The inlet on one side of the ejector is connected to the condenser liquid extraction bag, and the inlet on the other side is connected to the evaporator liquid extraction bag. A solenoid valve is connected in series on the pipeline connecting the evaporator, and the outlet is connected to the cooling pipeline. Through the injection of liquid, under the high-temperature heat pump working condition, liquid refrigerant with a lower temperature can still be obtained to ensure the cooling effect, and with the appropriate throttling orifice plate, the throttling loss is reduced and the energy efficiency of the unit is improved.

[0051] In the fourth embodiment, the present invention provides an air conditioner, including the refrigeration system provided in the third embodiment. In the refrigeration system, the ejector inlet of the cooling pipeline is connected to the condenser, and the refrigerant can be obtained from the condenser. The ejector port is connected to the evaporator through a solenoid valve, and the outlet is connected to the compressor through an electronic expansion valve. The controller controls the opening and closing of the solenoid valve. When the unit operates at a low pressure ratio, the controller controls the solenoid valve to close, and there is a pressure difference between the ejector inlet and outlet, so that the ejector can provide sufficient refrigerant to the compressor; when the unit operates at a high pressure ratio, the controller opens the solenoid valve to reduce the refrigerant temperature at the ejector outlet. In this way, regardless of the low pressure ratio or the high pressure ratio, the ejector inlet and outlet pressure difference of the cooling pipeline is sufficient, so that the ejector can provide sufficient refrigerant to the compressor, ensuring the cooling effect of the cooling pipeline and the reliable operation of the unit.

[0052] In a fifth embodiment, the present invention provides a compressor cooling control method, which is applied to the refrigeration system provided in the third embodiment, such as Figure 3 As shown, the control method includes the following steps:

[0053] S11: Obtaining parameters in multiple refrigeration cycle loops;

[0054] S12: Control components of the refrigeration system according to parameters.

[0055] Specifically, the parameters include the operating status of the compressor, and the components of the refrigeration system are controlled according to the parameters, including: when a start command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling pipeline is controlled to open; when a stop command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling pipeline is controlled to close after a preset delay.

[0056] The parameters include the compressor winding temperature, and the components of the refrigeration system are controlled according to the parameters, including: when the compressor is running, controlling the opening of the independent electronic expansion valve corresponding to the compressor according to the winding temperature.

[0057] The parameters include the difference between the condenser pressure and the evaporator pressure. The components of the refrigeration system are controlled according to the parameters, including: when the difference is greater than a first preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to open; when the difference is less than a second preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to close.

[0058] The parameters include the real-time power of the unit in which the refrigeration system is located, and the components of the refrigeration system are controlled according to the parameters, including: controlling the opening of the first electronic expansion valve in the first cooling pipeline according to the real-time power.

[0059] Taking the dual compressor refrigeration cycle in the second embodiment as an example, the specific control method is described. After the unit is started, the controller reads the condensing pressure Pc and evaporating pressure Pe of the refrigeration unit, and calculates the pressure difference △P=Pc-Pe. When △P<P SET (P SET , cooling liquid taking solenoid valve set pressure difference), the third solenoid valve SV3 and the fourth solenoid valve SV4 are closed; when △P>K1*P SET , (K1, cooling liquid taking solenoid valve pressure difference proportional coefficient, set according to actual needs), the third solenoid valve SV3 and the fourth solenoid valve SV4 are opened; when P SET <△P<K1*P SET , the third solenoid valve SV3 and the fourth solenoid valve SV4 maintain the state. When the machine is shut down, the third solenoid valve SV3 and the fourth solenoid valve SV4 are closed.

[0060] Control method of the first electronic expansion valve EVX1 in the first cooling pipeline:

[0061] 1) When powered on for the first time, the first electronic expansion valve EVX1 performs a reset action. The reset action is to first open it to 100%, then close it to 120% (close it to 0, indicating that it is quickly closed), and then open it to the initial opening D0. D0 is determined according to actual needs.

[0062] 2) After detecting the unit start-up command, the electronic expansion valve EVX1 is controlled by the unit power rate, and the target opening of the electronic expansion valve EVX1 is D1=A*Q+B, (A is the opening proportional coefficient of the first electronic expansion valve EVX1; Q is the power rate (Q=unit real-time power / rated power); B is a constant), and the opening is adjusted once every first preset time period, and the first preset time period is determined according to actual conditions. In particular, when D1<D0, D1=D0.

[0063] 3) After the unit shutdown is detected, the first electronic expansion valve EVX1 opens to the initial opening degree D0 after a delay of 60S.

[0064] Control method of the first solenoid valve SV1 and the second solenoid valve SV2 of the second cooling pipeline:

[0065] When the unit detects the start-up command of the first compressor M1 or the second compressor M2, the first solenoid valve SV1 and the second solenoid valve SV2 on the corresponding branch are opened; when the unit detects that the first compressor M1 or the second compressor M2 has been shut down, the first solenoid valve SV1 and the second solenoid valve SV2 on the corresponding branch are closed after a delay of 60s, and the opening command of the first solenoid valve SV1 and the second solenoid valve SV2 has a higher priority than the closing command.

[0066] Control method of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3 of the second cooling pipeline:

[0067] 1) When the electronic expansion valve is powered on for the first time, a reset action is performed, which is to open 100% first, close 120%, and then open to the initial opening D4 of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3. It should be noted that the initial openings of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3 can be different or the same, and the embodiment of the present invention is described as the same.

[0068] 2) After the compressor is detected to be started, after a delay of 60s, the opening of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3 are controlled by the corresponding compressor winding temperature, and the action cycle is adjusted once every second preset time length and third preset time length respectively. The second preset time length and the third preset time length are determined according to actual conditions).

[0069] Electronic expansion valve adjustment target: compressor winding temperature T 压缩机绕组 ±3℃;

[0070] Compressor winding temperature deviation △T: Compressor winding temperature -T 压缩机绕组 ;

[0071] When the compressor winding temperature deviation △T is within ±3℃: the opening degree of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3 does not change;

[0072] When the compressor winding temperature deviation △T is outside ±3℃:

[0073] The second electronic expansion valve EVX2 opening increment D2 = Kp*△T1, Kp is the opening increment proportional coefficient of the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3, Kp can be set according to actual needs, △T1 is the compressor winding temperature deviation of the first compressor M1 connected to the branch where the second electronic expansion valve EVX2 is located;

[0074] Similarly, the opening increment D3 of the third electronic expansion valve EVX3 = Kp*△T2, Kp can be set according to actual needs, and △T2 is the compressor winding temperature deviation of the second compressor M2 connected to the branch where the third electronic expansion valve EVX3 is located.

[0075] 3) After the unit shutdown is detected, the second electronic expansion valve EVX2 and the third electronic expansion valve EVX3 are opened to the initial opening degree D4 of the electronic expansion valves EVX2 and EVX3 after a delay of 60S.

[0076] The control method provided by the embodiment of the present invention controls the opening and closing of the solenoid valve by detecting the evaporation and condensation pressure difference and adopts injection to take liquid. The inlet on one side of the ejector is connected to the condenser liquid taking bag, and the inlet on the other side is connected to the evaporator liquid taking bag. A solenoid valve is connected in series on the pipeline connected to the evaporator, and the outlet is connected to the cooling pipeline. By injecting liquid, under the high-temperature heat pump working condition, liquid refrigerant with a lower temperature can still be obtained to ensure the cooling effect. In combination with a suitable throttling orifice plate, the throttling loss can be reduced and the energy efficiency of the unit can be improved.

[0077] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0078] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0079] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0080] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0081] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0082] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0083] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0085] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A compressor cooling structure, It is characterized in that Applicable to a multi-compressor refrigeration cycle loop, in which all compressors are connected in series, including a cooling pipeline and a return air pipeline; The cooling pipeline includes an ejector and an electronic expansion valve; The inlet of the ejector is connected to the condenser of the multi-compressor refrigeration cycle, the ejection port is connected to the evaporator of the multi-compressor refrigeration cycle, and the outlet of the ejector is respectively connected to each compressor of the multi-compressor refrigeration cycle through the electronic expansion valve to provide liquid refrigerant for each compressor; One end of the return air pipeline is connected to the compressor, and the other end is connected to the evaporator, so as to transport the refrigerant vaporized in the compressor to the evaporator.

2. The structure according to claim 1, Features: It also includes a controller, and an electromagnetic valve is arranged between the ejection port of the ejector and the evaporator; the electromagnetic valve is electrically connected to the controller, and when the difference between the pressure at the condenser and the pressure at the evaporator is greater than a first preset value, the controller controls the electromagnetic valve to open; when the difference between the pressure at the condenser and the pressure at the evaporator is less than a second preset value, the controller controls the electromagnetic valve to disconnect.

3. The structure according to claim 2, Features: The cooling pipeline includes a first cooling pipeline, and the outlet of a first ejector in the first cooling pipeline is respectively connected to each compressor of the multi-compressor refrigeration cycle loop through a first electronic expansion valve.

4. The structure according to claim 3, Features: The first electronic expansion valve is connected to the controller so that the controller controls the opening degree of the first electronic expansion valve according to the real-time power of the unit where the multi-compressor refrigeration cycle loop is located.

5. The structure according to claim 2, Features: The cooling pipeline includes a second cooling pipeline, and an independent electronic expansion valve is arranged between the outlet of the second ejector in the second cooling pipeline and each compressor of the multi-compressor refrigeration cycle loop.

6. The structure according to claim 5, Features: The independent electronic expansion valve is connected to the controller so that the controller controls the opening degree of the independent electronic expansion valve according to the winding temperature of the compressor connected to the independent electronic expansion valve.

7. The structure according to claim 5, Features: An independent solenoid valve is also provided between the outlet of the second ejector and each compressor of the multi-compressor refrigeration cycle circuit. The independent solenoid valve is connected to the controller. When the compressor connected to the independent solenoid valve is started, the controller controls the independent solenoid valve to open; when the compressor connected to the independent solenoid valve is stopped, the controller controls the independent solenoid valve to close.

8. The structure according to claim 1, Features: The outlet of the ejector is provided with a throttling orifice plate.

9. The structure according to claim 1, Features: The multi-compressor refrigeration cycle is a dual-compressor refrigeration cycle.

10. A refrigeration system, Features: The invention comprises the structure described in any one of claims 1 to 9.

11. An air conditioner, Features: A refrigeration system comprising the refrigeration system of claim 10.

12. A compressor cooling control method, It is characterized in that Applied to the refrigeration system of claim 10, the control method comprises the following steps: Obtain parameters in multiple refrigeration cycle loops; The components of the refrigeration system are controlled according to the parameters.

13. The method according to claim 12, Features: When the refrigeration system of claim 10 includes the structure of claim 7, the parameters include the operation status of the compressor, and the components of the refrigeration system controlled according to the parameters include: When a start command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling line is controlled to open; When a stop command of the compressor is detected, the independent solenoid valve corresponding to the compressor in the second cooling pipeline is controlled to close after a delay of a preset time.

14. The method according to claim 12, Features: When the refrigeration system of claim 10 includes the structure of claim 5, the parameter includes the compressor winding temperature, and the components of the refrigeration system controlled according to the parameter include: When the compressor is running, the opening degree of the independent electronic expansion valve corresponding to the compressor is controlled according to the winding temperature.

15. The method according to claim 12, Features: When the refrigeration system described in claim 2 includes the structure of claim 2, the cooling pipeline includes a first cooling pipeline, and the outlet of the first ejector in the first cooling pipeline is connected to each compressor of the multi-compressor refrigeration cycle through a first electronic expansion valve; the cooling pipeline includes a second cooling pipeline, and an independent electronic expansion valve is provided between the outlet of the second ejector in the second cooling pipeline and each compressor of the multi-compressor refrigeration cycle; The parameter includes a difference between a condenser pressure and an evaporator pressure, and the components of the refrigeration system are controlled according to the parameter, including: When the difference is greater than a first preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to open; When the difference is less than a second preset value, the solenoid valves of the first cooling pipeline and the second cooling pipeline are controlled to be closed.

16. The method according to claim 12, Features: When the refrigeration system of claim 10 includes the structure of claim 3, the parameter includes the real-time power of the unit where the refrigeration system is located, and the components of the refrigeration system controlled according to the parameter include: The opening degree of the first electronic expansion valve in the first cooling pipeline is controlled according to the real-time power.

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