Refrigerator performance prediction method and device, electronic equipment and storage medium

Abstract

Embodiments of the present application provide a refrigeration machine performance prediction method and device, electronic equipment and storage medium, belonging to the technical field of refrigeration machines. The method comprises: obtaining operating state parameters of a refrigeration machine unit, the refrigeration machine unit comprising a refrigerant system, the refrigerant system comprising an evaporator, a condenser and a compressor, the operating state parameters comprising a first saturation temperature and a steam superheat degree of the evaporator, a second saturation temperature and a liquid subcooling degree of the condenser, and a discharge temperature of the compressor; calculating a first energy efficiency coefficient of the refrigerant system according to the first saturation temperature, the steam superheat degree, the second saturation temperature, the liquid subcooling degree and the discharge temperature; obtaining a rolling bearing transmission efficiency and a motor efficiency of the refrigeration machine unit; and calculating a second energy efficiency coefficient of the refrigeration machine unit according to the rolling bearing transmission efficiency, the motor efficiency and the first energy efficiency coefficient. The embodiments of the present application can improve the accuracy of refrigeration machine performance prediction.

Description

Technical Field

[0001] This application relates to the field of refrigeration technology, and in particular to a method, apparatus, electronic device and storage medium for predicting the performance of a refrigeration machine. Background Technology

[0002] In related technologies, performance prediction models are used to predict the energy efficiency of refrigeration units. However, most performance prediction models are empirical models built based on the refrigeration unit's factory performance parameter curves, including parameters such as refrigeration unit energy efficiency, cooling load rate, chilled water temperature, and cooling water temperature. Due to the complexity of refrigeration units, empirical models have significant limitations and cannot fully reflect the thermodynamic nature of various operating conditions, resulting in low accuracy in refrigeration unit performance prediction. Summary of the Invention

[0003] The main objective of this application is to provide a method, apparatus, electronic device, and storage medium for predicting the performance of a refrigerator, aiming to improve the accuracy of refrigerator performance prediction.

[0004] To achieve the above objectives, a first aspect of this application proposes a method for predicting the performance of a refrigeration unit, the method comprising:

[0005] The operating status parameters of the refrigeration unit are obtained; wherein the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and vapor superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor;

[0006] The first energy efficiency coefficient of the refrigerant system is calculated based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature.

[0007] Obtain the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit;

[0008] The second energy efficiency coefficient of the refrigeration unit is calculated based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient.

[0009] In some embodiments, calculating the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, the vapor superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature includes:

[0010] Calculate the first saturation pressure of the evaporator based on the first saturation temperature;

[0011] Calculate the second saturation pressure of the condenser based on the second saturation temperature;

[0012] The first energy efficiency coefficient is calculated based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature.

[0013] In some embodiments, the compressor includes inlet guide vanes and a diffuser, and the refrigerant system further includes a throttling device and refrigerant. The calculation of the first efficiency coefficient based on the first saturation temperature, the first saturation pressure, the vapor superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature includes:

[0014] Based on the first saturation temperature, the first saturation pressure, and the steam superheat, the specific enthalpy of the refrigerant at the inlet of the guide vane is calculated to obtain the first inlet specific enthalpy;

[0015] Based on the second saturation temperature and the liquid subcooling, the specific enthalpy of the refrigerant at the inlet of the throttling device is calculated to obtain the second inlet specific enthalpy;

[0016] Based on the second saturation pressure and the exhaust temperature, the specific enthalpy of the refrigerant at the outlet of the diffuser is calculated to obtain the diffuser outlet specific enthalpy;

[0017] The first energy efficiency coefficient is calculated based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy.

[0018] In some embodiments, calculating the first energy efficiency coefficient based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy includes:

[0019] Calculate the specific refrigeration capacity per unit mass of the refrigerant in the evaporator based on the first inlet specific enthalpy and the second inlet specific enthalpy;

[0020] Calculate the specific input shaft work of the refrigerant per unit mass in the compressor based on the first inlet specific enthalpy and the diffuser outlet specific enthalpy;

[0021] The first energy efficiency coefficient is calculated based on the specific cooling capacity and the specific input shaft work.

[0022] In some embodiments, obtaining the rolling bearing transmission efficiency of the refrigeration unit includes:

[0023] Obtain the mapping relationship; wherein the mapping relationship is used to indicate the relationship between the bearing transmission efficiency of the refrigeration unit and the saturation temperature of the evaporator;

[0024] Based on the first saturation temperature and the mapping relationship, the bearing transmission efficiency of the refrigeration unit is calculated to obtain the rolling bearing transmission efficiency.

[0025] In some embodiments, calculating the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient includes:

[0026] Multiply the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient to obtain the first intermediate parameter;

[0027] The bearing transmission energy loss ratio is determined based on the rolling bearing transmission efficiency.

[0028] Multiply the motor efficiency by the bearing transmission energy loss ratio to obtain the second intermediate parameter;

[0029] Subtracting the first intermediate parameter from the second intermediate parameter yields the second energy efficiency coefficient.

[0030] In some embodiments, after calculating the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient, the method further includes:

[0031] Obtain the input electrical power of the refrigeration unit;

[0032] The cooling capacity of the refrigeration unit is predicted based on the input electrical power and the second energy efficiency coefficient.

[0033] To achieve the above objectives, a second aspect of this application provides a refrigerator performance prediction device, the device comprising:

[0034] The first acquisition module is used to acquire the operating status parameters of the refrigeration unit; wherein, the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and vapor superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor;

[0035] The first calculation module is used to calculate the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature.

[0036] The second acquisition module is used to acquire the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit.

[0037] The second calculation module is used to calculate the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient.

[0038] To achieve the above objectives, a third aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect.

[0039] To achieve the above objectives, a fourth aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0040] The refrigeration unit performance prediction method, device, electronic equipment, and computer-readable storage medium proposed in this application calculate the predicted energy efficiency of the refrigerant system based on operating parameters such as the first saturation temperature and steam superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the compressor discharge temperature, thus obtaining a first energy efficiency coefficient. To comprehensively reflect the thermodynamic nature of the refrigeration unit under various operating conditions, the influence of the rolling bearing transmission efficiency and motor efficiency on energy efficiency prediction is considered. Based on the rolling bearing transmission efficiency, motor efficiency, and the first energy efficiency coefficient, the predicted energy efficiency of the refrigeration unit is calculated, resulting in a second energy efficiency coefficient. This allows for accurate assessment of the real-time operating energy efficiency of the refrigeration unit, improving the accuracy of refrigeration performance prediction. Attached Figure Description

[0041] Figure 1 This is a flowchart of the refrigerator performance prediction method provided in the embodiments of this application;

[0042] Figure 2 yes Figure 1 The flowchart of step S120 in the middle;

[0043] Figure 3 yes Figure 2 The flowchart of step S230 in the middle;

[0044] Figure 4 yes Figure 3 The flowchart of step S340 in the text;

[0045] Figure 5 yes Figure 1 The flowchart of step S130 in the process;

[0046] Figure 6 This is a temperature entropy diagram of a typical single-stage centrifugal compression refrigeration cycle provided in the embodiments of this application;

[0047] Figure 7 This is a diagram illustrating the mapping relationship between bearing transmission efficiency and evaporator saturation temperature provided in the embodiments of this application.

[0048] Figure 8 yes Figure 1 The flowchart of step S140 in the middle;

[0049] Figure 9 This is another flowchart of the refrigerator performance prediction method provided in the embodiments of this application;

[0050] Figure 10 This is a schematic diagram of the structure of the refrigeration machine performance prediction device provided in the embodiments of this application;

[0051] Figure 11 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0053] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0055] The Coefficient of Performance (COP) of a fixed-frequency chiller is an energy efficiency indicator that evaluates the cooling capacity output per unit of input electrical work. Related technologies predict the chiller's energy efficiency using performance prediction models. However, most performance prediction models are empirical models built upon the chiller's factory performance parameter curves, incorporating parameters such as chiller energy efficiency, cooling load rate, chilled water temperature, and cooling water temperature. During real-time operation of the chiller, data such as cooling load rate, chilled water temperature, and cooling water temperature are measured, and the chiller's energy efficiency is obtained by combining the measured data with the empirical model. Due to the complexity of chillers, empirical models have significant limitations and cannot fully reflect the thermodynamic nature of various operating conditions, resulting in low accuracy in energy efficiency prediction. Consequently, it is difficult to accurately assess the real-time operating energy efficiency of the chiller, leading to low accuracy in chiller performance prediction.

[0056] Based on this, embodiments of this application provide a method, apparatus, electronic device, and computer-readable storage medium for predicting the performance of a refrigeration unit, aiming to improve the accuracy of refrigeration unit performance prediction.

[0057] The refrigerator performance prediction method, refrigerator performance prediction device, electronic device and computer-readable storage medium provided in the embodiments of this application are specifically described through the following embodiments. First, the refrigerator performance prediction method in the embodiments of this application is described.

[0058] The refrigeration performance prediction method provided in this application relates to the field of refrigeration technology. This method can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application implementing the refrigeration performance prediction method, but is not limited to the above forms.

[0059] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0060] Figure 1 This is an optional flowchart of the chiller performance prediction method provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S110 to S140.

[0061] Step S110: Obtain the operating status parameters of the refrigeration unit; wherein, the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and vapor superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor.

[0062] Step S120: Calculate the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, steam superheat, second saturation temperature, liquid subcooling, and exhaust temperature.

[0063] Step S130: Obtain the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit;

[0064] Step S140: Calculate the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, motor efficiency, and the first energy efficiency coefficient.

[0065] In step S110 of some embodiments, during the operation of the refrigeration unit, the operating status parameters of the refrigeration unit are measured in real time. These operating status parameters are physical quantities describing various states of the refrigeration unit during operation. The refrigeration unit is a dual-mode refrigeration unit, with both modes including ice-making and air-conditioning. The refrigeration unit includes a refrigerant system, which comprises an evaporator, a condenser, and a compressor. The operating status parameters include the saturation temperature of the evaporator (first saturation temperature), the vapor superheat of the evaporator, the saturation temperature of the condenser (second saturation temperature), the liquid subcooling of the condenser, and the discharge temperature of the compressor.

[0066] Please see Figure 2 In some embodiments, step S120 may include, but is not limited to, steps S210 to S230:

[0067] Step S210: Calculate the first saturation pressure of the evaporator based on the first saturation temperature;

[0068] Step S220: Calculate the second saturation pressure of the condenser based on the second saturation temperature;

[0069] Step S230: Calculate the first energy efficiency coefficient based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature.

[0070] In step S210 of some embodiments, a one-to-one functional relationship exists between saturation temperature and saturation pressure. Substituting the first saturation temperature of the evaporator into this functional relationship yields the first saturation pressure of the evaporator. This functional relationship is approximated using a polynomial, which includes coefficients, an independent variable, an exponent of the independent variable, and a dependent variable. The coefficients are the fitting coefficients between saturation pressure and saturation temperature. The independent variable can be saturation temperature, and the dependent variable can be saturation pressure. The functional relationship between saturation pressure and saturation temperature is expressed as follows:

[0071] ,

[0072] in, The saturation temperature is expressed in °C. This is the saturation pressure, expressed in kPa. , , , All are coefficients.

[0073] The coefficient values ​​are expressed in scientific notation, and the coefficient values ​​are shown in Table 1:

[0074] Table 1

[0075]

[0076] In step S220 of some embodiments, the condenser saturation pressure is a function of the condenser saturation temperature, expressed as:

[0077] ,

[0078] in, This indicates the second saturation pressure, i.e., the condenser saturation pressure; This indicates the second saturation temperature, which is the saturation temperature of the condenser. This represents the functional relationship between saturation pressure and saturation temperature.

[0079] Substituting the second saturation temperature of the condenser into the functional relationship mentioned in step S210, the second saturation pressure of the condenser is obtained.

[0080] In step S230 of some embodiments, the predicted energy efficiency of the refrigerant system is calculated based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature, thereby obtaining the first energy efficiency coefficient of the refrigerant system.

[0081] Through the above steps S210 to S230, the predicted energy efficiency of the refrigerant system can be obtained, and the predicted energy efficiency of the refrigeration unit can be calculated based on the predicted energy efficiency.

[0082] Please see Figure 3In some embodiments, step S230 may include, but is not limited to, steps S310 to S340:

[0083] Step S310: Calculate the specific enthalpy of the refrigerant at the inlet of the guide vane based on the first saturation temperature, the first saturation pressure, and the steam superheat, and obtain the first inlet specific enthalpy.

[0084] Step S320: Calculate the specific enthalpy of the refrigerant at the inlet of the throttling device based on the second saturation temperature and the liquid subcooling, and obtain the second inlet specific enthalpy;

[0085] Step S330: Calculate the specific enthalpy of the refrigerant at the diffuser outlet based on the second saturation pressure and exhaust temperature, and obtain the diffuser outlet specific enthalpy;

[0086] Step S340: Calculate the first energy efficiency coefficient based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy.

[0087] In step S310 of some embodiments, the compressor includes an inlet guide vane and a diffuser, and the refrigerant system also includes a throttling device and refrigerant. The throttling device can be a throttling valve, and the refrigerant is R134a refrigerant. The refrigerant is in a gaseous state at the inlet of the inlet guide vane and has a certain superheat, i.e., vapor superheat, which can be obtained by measurement. The first inlet specific enthalpy is the specific enthalpy of the superheated gas of the refrigerant at the inlet guide vane. By substituting the first saturation temperature, the first saturation pressure, and the vapor superheat into the superheated gas specific enthalpy formula, the specific enthalpy of the superheated gaseous refrigerant at the inlet guide vane inlet is calculated to obtain the first inlet specific enthalpy. The superheated gas specific enthalpy formula is a function of temperature and pressure, determined by the temperature of the superheated gas of the refrigerant and the saturation pressure of the evaporator. The superheated gas specific enthalpy formula is expressed as:

[0088] ,

[0089] Where h represents specific enthalpy, the unit is kJ / kg; the subscript g indicates that the refrigerant is in a superheated gaseous state; the subscript 0IGVin indicates the state point, the first digit 0 indicates the stagnation state, and IGVin indicates the IGV inlet of the guide vane; Indicates the specific enthalpy of a superheated gas; This represents the first saturation pressure, expressed in kPa. This indicates the first saturation temperature, expressed in °C. The value indicates the degree of steam superheat, in °C; + indicates the addition operator.

[0090] The relationship between the specific enthalpy of superheated gas and pressure and temperature can be approximated by a polynomial as follows:

[0091] ,

[0092] in, Indicates pressure, Indicates temperature; , , , , , , This is the fitting coefficient between the specific enthalpy of the superheated gas and pressure and temperature.

[0093] The fitting coefficients of the polynomials are expressed in scientific notation, as shown in Table 2:

[0094] Table 2

[0095]

[0096] In step S320 of some embodiments, the refrigerant is in a liquid state at the inlet of the throttling device, possessing a certain degree of subcooling, i.e., liquid subcooling, which can be obtained through measurement. The second inlet specific enthalpy is the specific enthalpy of the subcooled liquid at the inlet of the throttling device. Substituting the second saturation temperature and the liquid subcooling into the liquid specific enthalpy formula, the specific enthalpy of the saturated liquid refrigerant at the inlet of the throttling device is calculated, yielding the second inlet specific enthalpy. The liquid specific enthalpy mainly depends on temperature, with pressure having a relatively small impact. Therefore, the specific enthalpy of the subcooled liquid is approximately taken as the saturated liquid specific enthalpy corresponding to the refrigerant temperature.

[0097] The specific enthalpy of a liquid is a function of temperature and can be expressed as:

[0098] ,

[0099] Where h represents specific enthalpy, in kJ / kg; the subscript ls indicates that the refrigerant is in a saturated liquid state; the subscript throttlein indicates the inlet of the throttling device; Indicates the specific enthalpy of a saturated liquid; This indicates the second saturation temperature, expressed in °C. The symbol represents the degree of liquid subcooling, in °C; the hyphen (-) represents the subtraction operator.

[0100] The relationship between the specific enthalpy of a saturated liquid and its saturation temperature can be approximated by a polynomial as follows:

[0101] ,

[0102] in, This indicates the saturation temperature, expressed in °C. , , and All are fitting coefficients between the specific enthalpy of saturated liquid and the saturation temperature.

[0103] The fitting coefficients of the polynomials are expressed in scientific notation, as shown in Table 3:

[0104] Table 3

[0105]

[0106] Besides superheated gaseous and saturated liquid states, the physical states of refrigerants also include saturated gaseous states. The specific enthalpy of a saturated gaseous state is a function of the saturation temperature and can be approximated using a polynomial as follows:

[0107] ,

[0108] in, It is expressed as saturated gaseous enthalpy, with units of kJ / kg; This indicates the saturation temperature, expressed in °C. , , and This represents the fitting coefficient between the saturated gaseous specific enthalpy and the saturation temperature.

[0109] The fitting coefficients are shown in Table 4:

[0110] Table 4

[0111]

[0112] In step S330 of some embodiments, the diffuser outlet enthalpy is a function of temperature and pressure, and can be calculated from the stagnation temperature and stagnation pressure at the diffuser outlet. Substituting the second saturation pressure and discharge temperature into the superheated gas enthalpy formula, the enthalpy of the superheated gaseous refrigerant at the diffuser outlet is calculated, yielding the diffuser outlet enthalpy. The second saturation pressure of the condenser is approximated as the stagnation pressure, and the discharge temperature of the compressor is approximated as the stagnation temperature. The diffuser outlet enthalpy is expressed as:

[0113] ,

[0114] Where h represents specific enthalpy, the unit is kJ / kg; the subscript g indicates that the refrigerant is in a superheated gaseous state; the subscript 0VGDout indicates the state point, the first digit 0 indicates the stagnation state, and VGDout indicates the diffuser VGD outlet; Indicates the specific enthalpy of a superheated gas; This represents the second saturation pressure, expressed in kPa. This indicates the exhaust temperature, expressed in °C.

[0115] In step S340 of some embodiments, the first energy efficiency coefficient of the refrigerant system is calculated based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy.

[0116] Through the above steps S310 to S340, the energy efficiency of the refrigerant system can be predicted, so as to predict the energy efficiency of the refrigeration unit based on the energy efficiency of the refrigerant system.

[0117] Please see Figure 4 In some embodiments, step S340 may include, but is not limited to, steps S410 to S430:

[0118] Step S410: Calculate the specific cooling capacity of a unit mass of refrigerant in the evaporator based on the specific enthalpy of the first inlet and the specific enthalpy of the second inlet.

[0119] Step S420: Calculate the specific input shaft work of a unit mass of refrigerant in the compressor based on the first inlet specific enthalpy and the diffuser outlet specific enthalpy;

[0120] Step S430: Calculate the first energy efficiency coefficient based on the specific cooling capacity and specific input shaft work.

[0121] In step S410 of some embodiments, the first inlet specific enthalpy is the inlet specific enthalpy of the guide vane, and the second inlet specific enthalpy is the inlet specific enthalpy of the throttling device. Subtracting the first inlet specific enthalpy from the second inlet specific enthalpy yields the specific refrigeration capacity per unit mass of refrigerant, i.e., 1 kg of refrigerant, in the evaporator. The specific refrigeration capacity is expressed as:

[0122] ,

[0123] in, Indicates specific cooling capacity; Indicates the specific enthalpy of the first inlet; This indicates the enthalpy of the second inlet.

[0124] In step S420 of some embodiments, the specific input shaft work corresponding to a unit mass of refrigerant in the compressor is the difference between the specific enthalpy at the diffuser inlet and the specific enthalpy at the inlet guide vane outlet, which can be expressed as:

[0125] ,

[0126] in, Indicates the specific input shaft work; VGDin indicates the diffuser inlet. Indicates the diffuser inlet specific enthalpy; IGVout indicates the inlet guide vane outlet. This indicates the specific enthalpy of the imported guide vane.

[0127] The refrigerant's passage through the inlet guide vanes and diffuser is an adiabatic process, with equal enthalpy values ​​at the inlet and outlet, which can be expressed as:

[0128] ,

[0129] ,

[0130] in, Indicates the specific enthalpy of the imported guide vane at the outlet; This indicates the inlet enthalpy of the guide vane, i.e., the first inlet enthalpy; Indicates the diffuser inlet specific enthalpy; This indicates the diffuser outlet specific enthalpy.

[0131] The specific enthalpy at the diffuser outlet can be subtracted from the specific enthalpy at the first inlet to obtain the specific input shaft work per unit mass of refrigerant in the compressor. That is, the specific input shaft work can be re-expressed as:

[0132] ,

[0133] in, Indicates the work done by the input shaft; Indicates the diffuser outlet specific enthalpy; This indicates the enthalpy of the first inlet.

[0134] In step S430 of some embodiments, the ratio between specific cooling capacity and specific input shaft work is calculated to obtain the first energy efficiency coefficient of the refrigerant system. The first energy efficiency coefficient of the refrigerant system is expressed as:

[0135] ,

[0136] in, Indicates the first energy efficiency coefficient; This indicates the specific cooling capacity per unit mass of refrigerant in the evaporator, expressed in kJ / kg. This indicates the specific input shaft work per unit mass of refrigerant in the compressor, expressed in kJ / kg.

[0137] The first energy efficiency coefficient can also be expressed as:

[0138] ,

[0139] in, Specific enthalpy of the first inlet; Enthalpy of the second inlet; This is the specific enthalpy at the diffuser outlet.

[0140] Steps S410 to S430 above use specific enthalpy to reflect the thermophysical properties of the refrigerant, so as to accurately predict the energy efficiency of the refrigerant system based on specific enthalpy.

[0141] Obtain the rolling bearing transmission efficiency and motor efficiency of the dual-condition refrigeration unit. For AC motors, the motor efficiency is constant within a certain power range. Based on the refrigeration unit's motor nameplate, the AC motor efficiency can be determined to be 95.5%.

[0142] Please see Figure 5 In some embodiments, step 130 may include, but is not limited to, steps S510 to S520:

[0143] Step S510: Obtain the mapping relationship; wherein the mapping relationship is used to indicate the relationship between the bearing transmission efficiency of the refrigeration unit and the saturation temperature of the evaporator;

[0144] Step S520: Calculate the bearing transmission efficiency of the refrigeration unit based on the first saturation temperature and the mapping relationship, and obtain the rolling bearing transmission efficiency.

[0145] In step S510 of some embodiments, for rolling bearing drives, the evaporator refrigerant temperature affects the cooling of the bearing drive, while the refrigerant gas density affects the mechanical transmission friction. Therefore, the rolling bearing drive efficiency can be considered a function of the evaporator saturation temperature, expressed as:

[0146] ,

[0147] in, Indicates the bearing transmission efficiency; This indicates the saturation temperature of the evaporator; This represents the mapping relationship between bearing transmission efficiency and evaporator saturation temperature.

[0148] Please see Figure 6 , Figure 6 This is a temperature-entropy diagram for a typical single-stage centrifugal compression refrigeration cycle. The diagram illustrates four processes: condenser cooling, expansion valve throttling, evaporator refrigeration, and compressor compression. Compressor compression further includes three processes: inlet guide vane adjustment, impeller compression, and diffuser adjustment. For a dual-condition refrigeration unit, the evaporator temperature can vary from -6.6℃ to 6℃. Statistical analysis was performed on different operating conditions of the refrigeration unit, and regression analysis was conducted to obtain the mapping relationship between the bearing transmission efficiency of the refrigeration unit and the saturation temperature of the evaporator. The mapping relationship is shown below. Figure 7 As shown. The mapping relationship is approximated using a polynomial as follows:

[0149] ,

[0150] in, This indicates the saturation temperature of the evaporator; , , The fitting coefficients are those of the polynomial.

[0151] The fitting coefficients are shown in Table 5:

[0152] Table 5

[0153]

[0154] This mapping relationship highlights a difference in the impact of dual-mode refrigeration units and base-load refrigeration units on refrigeration unit performance. The main reason is that dual-mode refrigeration is divided into ice-making and air-conditioning modes, where the evaporator saturation temperature can vary widely, from -6.6℃ to 6℃. Calculations and analysis show that if the rolling bearing efficiency is set to a constant, similar to the efficiency of AC motors, there will be significant errors in the predicted COP and cooling capacity values ​​for both ice-making and air-conditioning modes.

[0155] In step S520 of some embodiments, the first saturation temperature is substituted into the mapping relationship to calculate the bearing transmission efficiency of the refrigeration unit and obtain the rolling bearing transmission efficiency.

[0156] By considering the impact of evaporator temperature on bearing transmission efficiency during dual-condition operation, the above steps S510 to S520 can improve the accuracy of energy efficiency prediction.

[0157] The overall energy efficiency COP of a refrigeration unit is expressed as:

[0158] ,

[0159] in, The specific cooling capacity per unit mass of refrigerant in a refrigeration unit, expressed in kJ / kg; This is the specific electrical work per unit mass of refrigerant in the refrigeration unit, expressed in kJ / kg.

[0160] The specific input shaft work per unit mass of refrigerant in a fixed-frequency compressor can be expressed as:

[0161] ,

[0162] in, This indicates the specific electrical work output per unit mass of refrigerant. , These represent the motor efficiency and the rolling bearing transmission efficiency, respectively.

[0163] For single-stage centrifugal compressors using open-loop motors, refrigerant is typically used for bearing drive for cooling, consuming a portion of the evaporator's cooling capacity, which can be expressed as:

[0164] ,

[0165] in, This indicates the specific cooling capacity per unit mass of refrigerant in the evaporator.

[0166] Or it can be expressed as:

[0167] ,

[0168] then:

[0169] ,

[0170] ,

[0171] in, This represents the first energy efficiency coefficient of the refrigerant system; This indicates the energy efficiency coefficient of the refrigeration unit.

[0172] The rolling bearing transmission efficiency of a dual-condition refrigeration unit can be calculated based on the above mapping relationship. In some embodiments, if the above mapping relationship does not exist, the cooling capacity of the refrigeration unit can be measured. and the power of the refrigeration unit motor The energy efficiency of the refrigeration unit is obtained by calculating the ratio between the cooling capacity and the motor power. Based on the above The calculation formula is based on the measured energy efficiency of the refrigeration unit. The first energy efficiency coefficient of the refrigeration unit refrigerant system In addition to the motor efficiency, the bearing transmission efficiency was calculated. As the evaporator temperature decreases, the rolling bearing transmission efficiency increases to some extent.

[0173] Please see Figure 8 In some embodiments, step 140 may include, but is not limited to, steps S810 to S840:

[0174] Step S810: Multiply the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient to obtain the first intermediate parameter;

[0175] Step S820: Determine the bearing transmission energy loss ratio based on the rolling bearing transmission efficiency;

[0176] Step S830: Multiply the motor efficiency and the bearing transmission energy loss ratio to obtain the second intermediate parameter;

[0177] Step S840: Subtract the first intermediate parameter and the second intermediate parameter to obtain the second energy efficiency coefficient.

[0178] In step S810 of some embodiments, this application embodiment considers the influence of bearing transmission efficiency on evaporator temperature changes and proposes a theoretical model for the energy efficiency COP of a dual-condition fixed-frequency centrifugal chiller, namely the COP calculation formula including the first energy efficiency coefficient mentioned above. This model can be used to predict the real-time operating energy efficiency COP of the dual-condition fixed-frequency centrifugal chiller, thereby enabling real-time analysis and optimization of operating performance. The chiller's operating conditions include ice-making condition, air-conditioning condition, and transition condition between the two conditions.

[0179] Increase the transmission efficiency of rolling bearings Motor efficiency and the first energy efficiency coefficient Multiply them to obtain the first intermediate parameter.

[0180] In step S820 of some embodiments, 1 is subtracted from the rolling bearing transmission efficiency to obtain the bearing transmission energy loss ratio.

[0181] In step S830 of some embodiments, the motor efficiency is... Multiplying this by the ratio of energy loss in bearing transmission yields the second intermediate parameter.

[0182] In step S840 of some embodiments, the first intermediate parameter and the second intermediate parameter are subtracted to predict the energy efficiency of the chiller unit and obtain the second energy efficiency coefficient.

[0183] Through the above steps S810 to S840, the energy efficiency of the chiller unit can be accurately and in real time predicted.

[0184] Please see Figure 9 In some embodiments, after step S140, the refrigerator performance prediction method may also include, but is not limited to, steps S910 to S920:

[0185] Step S910: Obtain the input electrical power of the chiller unit;

[0186] Step S920: Predict the cooling capacity of the chiller unit based on the input electrical power and the second energy efficiency coefficient.

[0187] In step S910 of some embodiments, for many operating refrigeration systems, there is no refrigeration capacity measurement device installed. In order to achieve adaptive and accurate prediction of refrigeration capacity, the specific input electrical work corresponding to the unit mass of refrigerant of the refrigeration unit is obtained, and the input electrical power of the refrigeration unit distribution cabinet is obtained.

[0188] In step S920 of some embodiments, the input electrical power and the second energy efficiency coefficient are multiplied to predict the cooling capacity of the chiller unit. The formula for calculating the cooling capacity is expressed as:

[0189] ,

[0190] in, This indicates the cooling capacity of the refrigeration unit; Indicates input electrical power; This represents the second energy efficiency coefficient of the refrigeration unit; This represents the multiplication operator.

[0191] Through the above steps S910 to S920, the cooling capacity of the refrigeration unit can be accurately predicted.

[0192] This application proposes a performance prediction method for a dual-condition fixed-frequency single-stage centrifugal compressor refrigerator. By measuring the refrigerant state parameters during compressor operation and combining this with a model of bearing transmission efficiency varying with evaporator temperature, the real-time energy efficiency coefficient of performance (COP) of the dual-condition single-stage centrifugal compressor refrigerator is predicted. Furthermore, based on the measured input power of the refrigerator, the real-time cooling capacity is predicted. The model considers the impact of evaporator temperature on refrigerator performance at different cooling temperatures during ice-making and air-conditioning operations. According to the method proposed in this application, the real-time COP of the refrigerator can be accurately predicted even without measuring the refrigerator's cooling capacity. It can also be used to predict the real-time cooling capacity of the refrigerator under ice-making and air-conditioning conditions, and can be used to verify the accuracy of dual-condition refrigerator cooling capacity measurements. The prediction model in this application is based on a thermodynamic theoretical model of refrigerant thermodynamic cycle efficiency and efficiency characteristic models of motors, bearing transmissions, etc. It has few parameter variables, is simple and convenient to use, and has a wide range of applications due to the use of a refrigerator theoretical model combined with the actual thermal properties of the refrigerant.

[0193] Please see Figure 10 This application also provides a refrigerator performance prediction device, which can implement the above-described refrigerator performance prediction method. The refrigerator performance prediction device includes:

[0194] The first acquisition module 1010 is used to acquire the operating status parameters of the refrigeration unit; wherein, the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and steam superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor;

[0195] The first calculation module 1020 is used to calculate the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, steam superheat, second saturation temperature, liquid subcooling and exhaust temperature;

[0196] The second acquisition module 1030 is used to acquire the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit.

[0197] The second calculation module 1040 is used to calculate the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, motor efficiency, and the first energy efficiency coefficient.

[0198] The specific implementation of this refrigeration machine performance prediction device is basically the same as the specific embodiment of the refrigeration machine performance prediction method described above, and will not be repeated here.

[0199] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described refrigerator performance prediction method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0200] Please see Figure 11 , Figure 11 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0201] The processor 1110 can be implemented using a general-purpose central processing unit (CPU), microprocessor, application specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0202] The memory 1120 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 1120 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 1120 and is called and executed by the processor 1110 using the refrigerator performance prediction method of the embodiments of this application.

[0203] The input / output interface 1130 is used to implement information input and output;

[0204] The communication interface 1140 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0205] Bus 1150 transmits information between various components of the device (e.g., processor 1110, memory 1120, input / output interface 1130, and communication interface 1140);

[0206] The processor 1110, memory 1120, input / output interface 1130 and communication interface 1140 are connected to each other within the device via bus 1150.

[0207] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described refrigerator performance prediction method.

[0208] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0209] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0210] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0211] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0212] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0213] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0214] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0215] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0216] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0217] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0218] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0219] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for predicting the performance of a refrigeration unit, characterized in that, The method includes: The operating status parameters of the refrigeration unit are obtained; wherein the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and vapor superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor; The first energy efficiency coefficient of the refrigerant system is calculated based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature. Obtain the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit; The second energy efficiency coefficient of the refrigeration unit is calculated based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient. The calculation of the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature includes: The first saturation pressure of the evaporator is calculated based on the first saturation temperature; the second saturation pressure of the condenser is calculated based on the second saturation temperature; the first energy efficiency coefficient is calculated based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature. The compressor includes inlet guide vanes and a diffuser, and the refrigerant system further includes a throttling device and refrigerant. The calculation of the first energy efficiency coefficient based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature includes: Based on the first saturation temperature, the first saturation pressure, and the steam superheat, the specific enthalpy of the refrigerant at the inlet of the guide vane is calculated to obtain the first inlet specific enthalpy; based on the second saturation temperature and the liquid subcooling, the specific enthalpy of the refrigerant at the inlet of the throttling device is calculated to obtain the second inlet specific enthalpy; based on the second saturation pressure and the exhaust temperature, the specific enthalpy of the refrigerant at the outlet of the diffuser is calculated to obtain the diffuser outlet specific enthalpy; based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy, the first energy efficiency coefficient is calculated; The step of calculating the second energy efficiency coefficient of the refrigeration unit based on the transmission efficiency of the rolling bearing, the efficiency of the motor, and the first energy efficiency coefficient includes: Multiply the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient to obtain a first intermediate parameter; determine the bearing transmission energy loss ratio based on the rolling bearing transmission efficiency; multiply the motor efficiency and the bearing transmission energy loss ratio to obtain a second intermediate parameter; subtract the first intermediate parameter from the second intermediate parameter to obtain the second energy efficiency coefficient.

2. The method according to claim 1, characterized in that, The calculation of the first energy efficiency coefficient based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy includes: Calculate the specific refrigeration capacity per unit mass of the refrigerant in the evaporator based on the first inlet specific enthalpy and the second inlet specific enthalpy; Calculate the specific input shaft work of the refrigerant per unit mass in the compressor based on the first inlet specific enthalpy and the diffuser outlet specific enthalpy; The first energy efficiency coefficient is calculated based on the specific cooling capacity and the specific input shaft work.

3. The method according to claim 1, characterized in that, The process of obtaining the rolling bearing transmission efficiency of the refrigeration unit includes: Obtain the mapping relationship; wherein the mapping relationship is used to indicate the relationship between the bearing transmission efficiency of the refrigeration unit and the saturation temperature of the evaporator; Based on the first saturation temperature and the mapping relationship, the bearing transmission efficiency of the refrigeration unit is calculated to obtain the rolling bearing transmission efficiency.

4. The method according to any one of claims 1 to 3, characterized in that, After calculating the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient, the method further includes: Obtain the input electrical power of the refrigeration unit; The cooling capacity of the refrigeration unit is predicted based on the input electrical power and the second energy efficiency coefficient.

5. A refrigeration machine performance prediction device, characterized in that, The device includes: The first acquisition module is used to acquire the operating status parameters of the refrigeration unit; wherein, the refrigeration unit includes a refrigerant system, the refrigerant system includes an evaporator, a condenser and a compressor, and the operating status parameters include the first saturation temperature and vapor superheat of the evaporator, the second saturation temperature and liquid subcooling of the condenser, and the discharge temperature of the compressor; The first calculation module is used to calculate the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature. The second acquisition module is used to acquire the rolling bearing transmission efficiency and motor efficiency of the refrigeration unit. The second calculation module is used to calculate the second energy efficiency coefficient of the refrigeration unit based on the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient. The calculation of the first energy efficiency coefficient of the refrigerant system based on the first saturation temperature, the steam superheat, the second saturation temperature, the liquid subcooling, and the exhaust temperature includes: The first saturation pressure of the evaporator is calculated based on the first saturation temperature; the second saturation pressure of the condenser is calculated based on the second saturation temperature; the first energy efficiency coefficient is calculated based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature. The compressor includes inlet guide vanes and a diffuser, and the refrigerant system further includes a throttling device and refrigerant. The calculation of the first energy efficiency coefficient based on the first saturation temperature, the first saturation pressure, the steam superheat, the second saturation temperature, the second saturation pressure, the liquid subcooling, and the exhaust temperature includes: Based on the first saturation temperature, the first saturation pressure, and the steam superheat, the specific enthalpy of the refrigerant at the inlet of the guide vane is calculated to obtain the first inlet specific enthalpy; based on the second saturation temperature and the liquid subcooling, the specific enthalpy of the refrigerant at the inlet of the throttling device is calculated to obtain the second inlet specific enthalpy; based on the second saturation pressure and the exhaust temperature, the specific enthalpy of the refrigerant at the outlet of the diffuser is calculated to obtain the diffuser outlet specific enthalpy; based on the first inlet specific enthalpy, the second inlet specific enthalpy, and the diffuser outlet specific enthalpy, the first energy efficiency coefficient is calculated; The step of calculating the second energy efficiency coefficient of the refrigeration unit based on the transmission efficiency of the rolling bearing, the efficiency of the motor, and the first energy efficiency coefficient includes: Multiply the rolling bearing transmission efficiency, the motor efficiency, and the first energy efficiency coefficient to obtain a first intermediate parameter; determine the bearing transmission energy loss ratio based on the rolling bearing transmission efficiency; multiply the motor efficiency and the bearing transmission energy loss ratio to obtain a second intermediate parameter; subtract the first intermediate parameter from the second intermediate parameter to obtain the second energy efficiency coefficient.

6. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 4.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 4.

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