Centrifugal compressor performance data determination method, centrifugal compressor performance optimization method

Abstract

The embodiment of the application provides a centrifugal compressor performance data determination method and a centrifugal compressor performance optimization method, and belongs to the technical field of centrifugal compressors. The method comprises the following steps: combining an inlet guide vane opening degree and a compressor rotating speed to obtain a running mode combination; grouping original compressor running parameters based on the running mode combination to obtain grouped running parameters, including evaporator parameters, condenser parameters, refrigeration machine refrigeration capacity and unit running efficiency parameters; calculating a compressor flow coefficient and a pressure ratio according to the evaporator parameters, the condenser parameters and the refrigeration machine refrigeration capacity; calculating a compressor isentropic compression efficiency according to the condenser parameters; calculating a unit isentropic compression efficiency based on the unit running efficiency parameters and the compressor isentropic compression efficiency; and constructing a performance curve based on the compressor flow coefficient, the pressure ratio, the compressor isentropic compression efficiency and the unit isentropic compression efficiency. The embodiment of the application can accurately obtain performance data of a centrifugal compressor and improve the accuracy of performance optimization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal compressors, in particular to a centrifugal compressor performance data determination method and a centrifugal compressor performance optimization method. BACKGROUND

[0002] A centrifugal compressor is a power machine that applies force to gas through a high-speed rotating impeller to achieve efficient conversion of mechanical energy into gas pressure energy and kinetic energy. Centrifugal compressors are widely used in fields such as aircraft engines, gas turbine power generation, process flow pressurization, and large refrigerators. Large refrigerators are used in civil building refrigeration systems or factory cooling systems.

[0003] A centrifugal compressor is a component of a refrigerator unit. During use, the refrigerator unit automatically adjusts and controls according to the system environment, and is isolated from the user's refrigeration control system. However, it is difficult to accurately obtain the performance data of the centrifugal compressor, which makes it difficult to independently adjust and control the operation parameters of the refrigerator during use and to optimize the operation performance of the compressor.

[0004] Therefore, how to accurately obtain the performance data of the centrifugal compressor to improve the accuracy of performance optimization has become a technical problem to be solved. SUMMARY

[0005] The main purpose of the embodiments of the present application is to provide a centrifugal compressor performance data determination method and a centrifugal compressor performance optimization method, which are designed to accurately obtain the performance data of the centrifugal compressor to improve the accuracy of performance optimization.

[0006] To achieve the above-mentioned purpose, a first aspect of the embodiments of the present application provides a centrifugal compressor performance data determination method, which comprises:

[0007] Obtaining original compressor operating parameters; wherein the original compressor operating parameters include inlet guide vane opening and compressor speed;

[0008] Combining the inlet guide vane opening and the compressor speed to obtain a running mode combination;

[0009] Grouping the original compressor operating parameters based on the running mode combination to obtain grouped operating parameters; wherein the grouped operating parameters include evaporator parameters, condenser parameters, refrigerator refrigeration capacity, compressor discharge parameters, and unit operating efficiency parameters;

[0010] Calculating the flow coefficient according to the evaporator parameters, the condenser parameters, and the refrigerator refrigeration capacity to obtain the compressor flow coefficient and the compressor pressure ratio;

[0011] The compression efficiency is calculated based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters to obtain the compressor's isentropic compression efficiency.

[0012] The isentropic compression efficiency of the compressor unit is calculated based on the unit operating efficiency parameters and the compressor isentropic compression efficiency.

[0013] The compressor performance curve is obtained by constructing curves based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency.

[0014] In some embodiments, the evaporator parameters include evaporator saturation temperature and evaporator saturation pressure, and the condenser parameters include condenser saturation temperature and condenser saturation pressure; the step of calculating the compressor flow coefficient and compressor pressure ratio based on the evaporator parameters, the condenser parameters, and the refrigeration capacity of the refrigeration unit includes:

[0015] The saturated gas phase enthalpy of the evaporator is calculated based on the evaporator saturation temperature.

[0016] The saturated liquid phase enthalpy of the condenser is calculated based on the condenser saturation temperature.

[0017] The refrigeration capacity per unit refrigerant ratio is calculated based on the enthalpy of the saturated gas phase of the evaporator and the enthalpy of the saturated liquid phase of the condenser.

[0018] The refrigerant mass flow rate is calculated based on the cooling capacity of the refrigeration mechanism and the cooling capacity per unit refrigerant ratio.

[0019] The compressor flow coefficient is calculated based on the evaporator saturation temperature, the evaporator saturation pressure, and the refrigerant mass flow rate.

[0020] The compressor pressure ratio is calculated based on the evaporator saturation pressure and the condenser saturation pressure.

[0021] In some embodiments, the compressor discharge parameters include the compressor discharge temperature; the compression efficiency is calculated based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters to obtain the compressor's isentropic compression efficiency, including:

[0022] The compressor discharge enthalpy is calculated based on the compressor discharge temperature and the condenser saturation pressure.

[0023] The compressor specific shaft work per unit mass of refrigerant is calculated based on the enthalpy of the saturated gas in the evaporator and the enthalpy of the compressor exhaust gas.

[0024] The isentropic compression exhaust ratio enthalpy is calculated based on the evaporator saturation pressure, the evaporator saturation temperature, and the condenser saturation pressure.

[0025] The isentropic compression ratio shaft work per unit mass of refrigerant is calculated based on the enthalpy of the saturated gas phase of the evaporator and the enthalpy of the isentropic compression exhaust phase.

[0026] The isentropic compression efficiency of the compressor is obtained by calculating based on the compressor's specific shaft work and the isentropic compression specific shaft work.

[0027] In some embodiments, grouping the original compressor operating parameters based on the operating mode combination to obtain grouped operating parameters includes:

[0028] Based on the combination of operating modes, the original compressor operating parameters are grouped to obtain the initial compressor operating parameters;

[0029] The initial compressor operating parameters are segmented to obtain segmented operating parameters;

[0030] Stability screening is performed based on the sharding operation parameters to obtain the grouping operation parameters.

[0031] To achieve the above objectives, a second aspect of this application proposes a method for optimizing the performance of a centrifugal compressor, the method comprising:

[0032] Obtain the current operating parameters of the target centrifugal compressor;

[0033] Obtain a reference performance curve for the target centrifugal compressor; wherein the reference performance curve is obtained by the method described in the first aspect;

[0034] Based on the current operating parameters and the benchmark performance curve, the target optimization parameters are obtained by confirming the parameters.

[0035] The performance of the target centrifugal compressor is optimized based on the target optimization parameters.

[0036] In some embodiments, the current operating parameters include the current guide vane opening and the current rotational speed; the step of confirming the parameters based on the current operating parameters and the baseline performance curve to obtain the target optimization parameters includes:

[0037] The current mode combination is obtained by combining the current guide vane opening and the current rotation speed.

[0038] Based on the current combination of modes, the baseline performance curves are filtered to obtain the target performance curve;

[0039] The optimal value is obtained by querying the target performance curve to obtain the target optimization parameters.

[0040] To achieve the above objectives, a third aspect of this application provides a centrifugal compressor performance data determination device, the device comprising:

[0041] The compressor operating parameter acquisition module is used to acquire raw compressor operating parameters, including inlet guide vane opening and compressor speed.

[0042] The mode combination module is used to combine the inlet guide vane opening and the compressor speed to obtain the operating mode combination;

[0043] The parameter grouping module is used to group the original compressor operating parameters based on the operating mode combination to obtain grouped operating parameters; wherein, the grouped operating parameters include evaporator parameters, condenser parameters, refrigeration unit cooling capacity, compressor discharge parameters, and unit operating efficiency parameters;

[0044] The flow coefficient calculation module is used to calculate the flow coefficient based on the evaporator parameters, the condenser parameters and the refrigeration capacity of the refrigeration unit, so as to obtain the compressor flow coefficient and the compressor pressure ratio.

[0045] The compressor efficiency calculation module is used to calculate the compression efficiency based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters, and obtain the compressor isentropic compression efficiency.

[0046] The unit efficiency calculation module is used to calculate the compressor unit's isentropic compression efficiency based on the unit's operating efficiency parameters and the compressor's isentropic compression efficiency.

[0047] The performance curve construction module is used to construct curves based on the compressor flow coefficient, the compressor pressure ratio, the compressor isentropic compression efficiency, and the compressor group isentropic compression efficiency to obtain the compressor performance curve.

[0048] To achieve the above objectives, a fourth aspect of this application provides a centrifugal compressor performance optimization device, the device comprising:

[0049] The current operating parameter acquisition module is used to acquire the current operating parameters of the target centrifugal compressor;

[0050] A performance curve acquisition module is used to acquire a reference performance curve of the target centrifugal compressor; wherein the reference performance curve is obtained by the method described in the first aspect;

[0051] The parameter confirmation module is used to confirm the parameters based on the current operating parameters and the benchmark performance curve to obtain the target optimization parameters.

[0052] The performance optimization module is used to optimize the performance of the target centrifugal compressor based on the target optimization parameters.

[0053] To achieve the above objectives, a fifth aspect of the present application provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method described in the first aspect or the method described in the second aspect.

[0054] To achieve the above objectives, a sixth 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 or the method described in the second aspect.

[0055] The centrifugal compressor performance data determination method and centrifugal compressor performance optimization method proposed in this application obtain the original compressor operating parameters, including the inlet guide vane opening and compressor speed. These original operating parameters are then combined to obtain operating mode combinations, comprehensively covering different compressor operating states. Next, the original compressor operating parameters are grouped based on the operating mode combinations to obtain grouped operating parameters, making data classification clearer and more reasonable, facilitating targeted analysis. These grouped operating parameters include evaporator parameters, condenser parameters, compressor discharge parameters, refrigeration capacity, and unit operating efficiency parameters. Further, flow coefficients are calculated based on the evaporator parameters, condenser parameters, and refrigeration capacity to obtain the compressor flow coefficient and compressor pressure ratio, accurately quantifying the compressor flow characteristics. Based on the evaporator parameters, condenser parameters, and compressor discharge parameters, the compressor isentropic compression efficiency is obtained, accurately assessing the efficiency of the compressor compression process. Finally, based on the unit operating efficiency parameters and the compressor isentropic compression efficiency, the compressor unit's isentropic compression efficiency is calculated, considering the overall efficiency of the compressor unit. Finally, based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency, curves are constructed to obtain compressor performance curves. These curves can intuitively, comprehensively, and accurately reflect the performance of the compressor under different operating modes, providing a strong basis for optimizing operation, improving energy efficiency, and ensuring stable equipment operation. Attached Figure Description

[0056] Figure 1 This is a flowchart of the method for determining centrifugal compressor performance data provided in the embodiments of this application;

[0057] Figure 2 yes Figure 1 The flowchart of step S104 in the process;

[0058] Figure 3 yesFigure 1 The flowchart of step S105 in the process;

[0059] Figure 4 Example graphs showing the pressure ratio versus compressor flow coefficient curves under different combinations of operating modes provided in embodiments of this application;

[0060] Figure 5 Example graphs showing the isentropic compression efficiency versus compressor flow coefficient curves under different combinations of operating modes provided in the embodiments of this application;

[0061] Figure 6 Example graphs showing the isentropic compression efficiency versus compressor flow coefficient curves of compressor units under different combinations of operating modes provided in embodiments of this application;

[0062] Figure 7 This is a flowchart of the centrifugal compressor performance optimization method provided in the embodiments of this application;

[0063] Figure 8 yes Figure 7 The flowchart of step S703 in the process;

[0064] Figure 9 This is a schematic diagram of the centrifugal compressor performance data determination device provided in the embodiments of this application;

[0065] Figure 10 This is a schematic diagram of the centrifugal compressor performance optimization device provided in the embodiments of this application;

[0066] Figure 11 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0067] 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.

[0068] 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.

[0069] 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.

[0070] First, let's analyze some of the terms used in this application:

[0071] A centrifugal compressor is a type of power-driven machine that uses a high-speed rotating impeller to apply force to gas, achieving efficient conversion of mechanical energy into gas pressure energy and kinetic energy. Centrifugal compressors are widely used in fields such as aero engines, gas turbine power generation, process flow pressurization, and large-scale refrigeration machines. Among them, large-scale refrigeration machines are ubiquitous in refrigeration systems of civil buildings or cooling systems of factory workshops.

[0072] Inlet guide vanes (IGVs) are non-rotating blade assemblies typically located before the first-stage moving blades of a compressor or centrifugal compressor. The core function of inlet guide vanes is to adjust the angle, velocity, and direction of airflow entering the impeller by changing the guide vane's installation angle, thereby regulating the compressor's flow rate and outlet pressure. This enables efficient operation and meets the demands of varying operating conditions, making them a crucial component for ensuring stable equipment operation.

[0073] A diffuser is a device used to reduce fluid velocity and increase fluid pressure, commonly found in turbomachinery (such as gas turbines and centrifugal compressors). The core structure of a diffuser is a gradually expanding flow channel. By allowing the high-speed fluid to gradually decelerate within the channel, and based on the principle of energy conservation, part of the fluid's kinetic energy is converted into pressure energy, thus achieving a pressurization effect. Diffusers effectively improve system efficiency, reduce energy loss, and play a crucial role in ensuring stable equipment operation and performance optimization.

[0074] Pressure ratio, the ratio of compressor discharge pressure to intake pressure, is an important parameter for measuring compressor workload and efficiency. In refrigeration, air conditioning, and gas compression, pressure ratio reflects the degree of gas compression, directly affecting compressor energy consumption, discharge temperature, and operational reliability. A higher pressure ratio indicates a higher degree of gas compression, but an excessively high pressure ratio can lead to increased compressor power consumption, decreased efficiency, and even equipment failure; therefore, it must be properly controlled.

[0075] Isentropic processes, in thermodynamics, describe a process in which the entropy of a system remains constant. They are commonly seen in reversible adiabatic changes (where there is no heat exchange and no dissipation). The core condition is that the entropy change is zero, meaning the entropy values ​​of the initial and final states of the system are equal. Isentropic processes require no heat exchange between the system and its surroundings and are reversible. They are often used as an ideal benchmark in engineering to analyze the limiting performance of equipment such as nozzles and turbines, and to guide the selection of design parameters for power generation systems.

[0076] Specific enthalpy is an important parameter in thermodynamics that describes the energy state of a unit mass of matter. It is defined as the sum of the specific thermodynamic energy (internal energy) of a substance and the work done (the product of pressure and specific volume). It is used to characterize the energy possessed by a unit mass of a substance in a certain state and is often used to analyze energy conversion and transfer in thermodynamic processes, such as heating, cooling, and phase transition.

[0077] Specific cooling capacity is a key indicator in the performance evaluation of refrigeration equipment. It refers to the amount of cooling that a unit mass or unit volume of refrigerant can provide in a refrigeration cycle. The unit is usually 1. (watts / kg) or (Watts per cubic meter). Specific cooling capacity reflects the cooling ability of a refrigerant per unit mass or volume. The higher the specific cooling capacity, the greater the cooling capacity that the equipment can provide with the same amount or volume of refrigerant, and the higher the cooling efficiency and economy.

[0078] Centrifugal compressors are components of refrigeration units. The performance curve of a compressor is a crucial basis for compressor design and operation guidance. Typically, compressor performance curves are measured at the compressor manufacturing plant. However, for centrifugal refrigeration units, the centrifugal compressor is part of the refrigeration unit itself; manufacturers only provide the overall performance data of the refrigeration unit, not the performance characteristic curves of the centrifugal compressor. Therefore, in the application of centrifugal refrigeration units, analysis of the refrigeration system is rarely based on the compressor's performance characteristics. Furthermore, a refrigeration unit is usually a "black box," automatically adjusting and controlling itself according to the system environment during operation, isolated from the user's refrigeration control system.

[0079] Currently, compressor performance testing is mainly based on the compressor performance testing standard ASME PTE 10-1997. This involves varying compressor inlet conditions (temperature, pressure, gas type), as well as parameters such as pressure ratio and flow rate, to measure compressor performance data. However, actual testing consumes a large amount of electrical power, the testing platform is complex, and the cost is high, especially for large compressors.

[0080] However, due to the difficulty in accurately obtaining performance data of centrifugal compressors, it is impossible to autonomously adjust and control the operating parameters of the refrigeration unit during use, making it difficult to optimize the operating performance of the compressor.

[0081] Based on this, embodiments of this application provide a method for determining centrifugal compressor performance data and a method for optimizing centrifugal compressor performance, aiming to accurately obtain the performance data of centrifugal compressors in order to improve the accuracy of performance optimization.

[0082] The centrifugal compressor performance data determination method and centrifugal compressor performance optimization method provided in this application are specifically described through the following embodiments. First, the centrifugal compressor performance data determination method in this application embodiment is described.

[0083] 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.

[0084] Figure 1 This is an optional flowchart of the centrifugal compressor performance data determination method provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S107.

[0085] Step S101: Obtain the original compressor operating parameters; wherein, the original compressor operating parameters include the inlet guide vane opening and the compressor speed;

[0086] Step S102: Combine the inlet guide vane opening and compressor speed to obtain the operating mode combination;

[0087] Step S103: Group the original compressor operating parameters based on the combination of operating modes to obtain grouped operating parameters; wherein, the grouped operating parameters include evaporator parameters, condenser parameters, refrigeration unit cooling capacity, compressor discharge parameters and unit operating efficiency parameters;

[0088] Step S104: Calculate the flow coefficient based on the evaporator parameters, condenser parameters, and refrigeration capacity of the refrigeration unit to obtain the compressor flow coefficient and compressor pressure ratio;

[0089] Step S105: Calculate the compression efficiency based on the evaporator parameters, condenser parameters, and compressor discharge parameters to obtain the compressor's isentropic compression efficiency;

[0090] Step S106: Calculate the compressor unit's isentropic compression efficiency based on the unit's operating efficiency parameters and the compressor's isentropic compression efficiency.

[0091] Step S107: Based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency, curves are constructed to obtain the compressor performance curve.

[0092] Steps S101 to S107, as illustrated in this embodiment, involve obtaining the original compressor operating parameters, including the inlet guide vane opening and compressor speed. These parameters are then combined to obtain operating mode combinations, comprehensively covering different compressor operating states. Next, the original compressor operating parameters are grouped based on the operating mode combinations to obtain grouped operating parameters, making data classification clearer and more reasonable, facilitating targeted analysis. These grouped operating parameters include evaporator parameters, condenser parameters, compressor discharge parameters, refrigeration unit cooling capacity, and unit operating efficiency parameters. Further, flow coefficients are calculated based on the evaporator parameters, condenser parameters, and refrigeration unit cooling capacity to obtain the compressor flow coefficient and compressor pressure ratio, accurately quantifying the compressor flow characteristics. Based on the evaporator parameters, condenser parameters, and compressor discharge parameters, the compressor isentropic compression efficiency is obtained, accurately assessing the efficiency of the compressor compression process. Finally, the compressor unit isentropic compression efficiency is calculated based on the unit operating efficiency parameters and the compressor isentropic compression efficiency, considering the overall efficiency of the compressor unit. Finally, based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency, curves are constructed to obtain compressor performance curves. These curves can intuitively, comprehensively, and accurately reflect the performance of the compressor under different operating modes, providing a strong basis for optimizing operation, improving energy efficiency, and ensuring stable equipment operation.

[0093] In step S101 of some embodiments, the original compressor operating parameters are operating data generated by the centrifugal compressor under actual operating conditions over a long period of time. According to the statistics of annual operating data, the number of times the diffuser and hot gas bypass of the base-load variable frequency centrifugal chiller are opened and the operating time are not many for most of the time. Here, the operating conditions of diffuser and hot gas bypass are not considered, and the focus is on the acquisition of compressor characteristic curves when the inlet guide vane changes and the compressor speed changes.

[0094] Refrigeration compressors typically store operating data in seconds, including parameters such as evaporation temperature, condensation temperature, compressor discharge temperature, inlet guide vane opening, compressor speed, and motor current. The automatic control system of a refrigeration system typically stores operating data in minutes, such as 10 minutes, including refrigeration capacity and input power. This application's embodiment combines the refrigeration compressor's stored data with the refrigeration system's stored data, performing data analysis within the same time period.

[0095] Specifically, the original compressor operating parameters include, but are not limited to, inlet guide vane opening, compressor speed, evaporator parameters, condenser parameters, compressor discharge parameters, refrigeration capacity, refrigeration unit input power, and unit operating efficiency parameters.

[0096] Among them, the inlet guide vane opening degree refers to the degree to which the guide vanes at the compressor inlet are open, which affects the flow rate and direction of the gas entering the compressor.

[0097] Compressor speed refers to the number of revolutions the compressor rotor makes per minute, which determines the compressor's working frequency and gas compression capacity.

[0098] Evaporator parameters refer to the operating parameters of the evaporator during the operation of the compressor, including indicators such as temperature and pressure.

[0099] Condenser parameters refer to the operating parameters of the condenser during the operation of the compressor, including indicators such as temperature and pressure.

[0100] Compressor discharge parameters refer to the operating parameters of the compressor's discharge port during operation, including indicators such as discharge temperature and pressure.

[0101] Cooling capacity refers to the amount of heat absorbed by a refrigeration system from the environment per unit time.

[0102] Unit operating efficiency parameters refer to the performance parameters of the refrigeration system during operation, such as compressor power, system energy consumption, and refrigeration unit input power (referring to the electrical energy input to the refrigeration unit distribution cabinet per unit time).

[0103] In step S102 of some embodiments, the operating mode combination is a set of operating states formed by combining the two key parameters, inlet guide vane opening and compressor speed, in different ways. Different combinations represent the compressor's operating modes under different working conditions, comprehensively covering various possible operating conditions of the compressor, and helping to gain a deeper understanding of the compressor's performance characteristics under different combinations. By analyzing multiple operating modes, the optimal operating mode can be found, improving the compressor's efficiency and stability.

[0104] For example, the opening degree of the inlet guide vane can be set to different opening degrees such as 50%, 55%, 60%, 65%, 70%, 75%, and 78%, with a value range of 0-100%. The compressor speed can be set to different speeds such as 1000 r / min, 1500 r / min, and 2000 r / min. By combining these, a variety of operating modes can be obtained.

[0105] It should be noted that for centrifugal compressors (especially variable frequency compressors), the speed of the motor is directly proportional to the frequency of the input power supply. Therefore, the compressor speed can be expressed using the power supply frequency.

[0106] For example:

[0107] Combination 1 is [36.5Hz, 70%], which means that the inlet guide vane opening is 70% and the compressor speed is the operating speed of the compressor when the power supply frequency is 36.5Hz.

[0108] Combination 1 is [45Hz, 77%], which means that the inlet guide vane opening is 77% and the compressor speed is the operating speed of the compressor when the power supply frequency is 45Hz.

[0109] Understandably, by combining the inlet guide vane opening and compressor speed, multiple operating mode combinations can be obtained, comprehensively covering various possible operating conditions of the compressor. This helps to gain a deeper understanding of the compressor's performance characteristics under different combinations. It also facilitates subsequent analysis of different modes to find the optimal operating mode, thereby improving the compressor's efficiency and stability.

[0110] It should be noted that, due to the constantly changing operating conditions of the refrigeration unit, all of the above parameters are constantly changing. Furthermore, given the slow changes in the operating conditions of the refrigeration system, when the refrigeration unit is in quasi-steady-state operation, the compressor is considered to be operating in a steady state, and the various operating parameters can be used to analyze the performance data of the centrifugal compressor.

[0111] Specifically, in some embodiments, step S103 may include, but is not limited to, the following steps:

[0112] The original compressor operating parameters are grouped based on the combination of operating modes to obtain the initial compressor operating parameters;

[0113] The initial compressor operating parameters are segmented into data fragments to obtain segmented operating parameters;

[0114] Stability screening is performed based on the segmented operation parameters to obtain the grouped operation parameters.

[0115] First, the original compressor operating parameters are grouped according to the combination of operating modes to obtain the initial compressor operating parameters. Then, the initial compressor operating parameters are segmented according to time sequence to obtain segmented operating parameters, thus refining the data granularity. Finally, stability screening is performed based on the segmented operating parameters to obtain the grouped operating parameters. Unstable data is eliminated, which can accurately focus on stable and effective compressor operating data, providing a high-quality foundation for subsequent analysis and improving the accuracy of the research.

[0116] In some embodiments, data grouping is equivalent to finding the data parameters corresponding to each combination of operating modes from the original compressor operating parameters to form the initial compressor operating parameters.

[0117] Next, the continuous initial compressor operating parameters can be divided into data segments according to preset time segment thresholds (e.g., 20 minutes or 30 minutes as time segment thresholds), which are called segmented operating parameters.

[0118] Finally, it is determined whether the variation range of the inlet guide vane opening in the segmented operating parameters is within the preset opening range, and whether the variation range of the compressor speed is within the preset speed range.

[0119] If the variation range of the inlet guide vane opening is within the preset opening range, and the variation range of the compressor speed is within the preset speed range, then the centrifugal compressor is considered to be operating in a quasi-steady state during this time period. This segmented operating parameter is selected as a set of valid data and used as the grouped operating parameter.

[0120] If the compressor speed changes within the preset speed range, but the inlet guide vane opening changes outside the preset opening range, then the centrifugal compressor is considered not to be operating in a quasi-steady state during that time period, and the segmented operating parameter is removed.

[0121] If the change range of the inlet guide vane opening is within the preset opening range, but the change range of the compressor speed is not within the preset speed range, then the centrifugal compressor is considered not to be operating in a quasi-steady state during this time period, and the segmented operating parameter is removed.

[0122] In one embodiment, if the inlet guide vane opening varies within the range of [-1%, 1%] and the compressor speed varies within the range of [-0.1Hz, 0.1Hz], then the centrifugal compressor is considered to be operating in a quasi-steady state during this time period.

[0123] In some embodiments,

[0124] Evaporator parameters include: evaporator saturation temperature and evaporator saturation pressure;

[0125] Condenser parameters include: condenser saturation temperature and condenser saturation pressure;

[0126] Compressor discharge parameters include: compressor discharge temperature;

[0127] The unit's operating efficiency parameters include: frequency converter efficiency, motor efficiency, and bearing transmission efficiency;

[0128] Please see Figure 2 In some embodiments, step S104 may include, but is not limited to, steps S201 to S206:

[0129] Step S201: Calculate the saturated gas phase enthalpy of the evaporator based on the evaporator saturation temperature;

[0130] Step S202: Calculate the saturated liquid phase enthalpy of the condenser based on the condenser saturation temperature;

[0131] Step S203: Calculate the specific cooling capacity based on the enthalpy of the saturated gas in the evaporator and the enthalpy of the saturated liquid in the condenser.

[0132] Step S204: Calculate the refrigerant mass flow rate based on the refrigeration capacity of the refrigeration mechanism and the refrigerant ratio per unit refrigerant.

[0133] Step S205: Calculate the compressor flow coefficient based on the evaporator saturation temperature, evaporator saturation pressure, and refrigerant mass flow rate;

[0134] Step S206: Calculate the compressor pressure ratio based on the evaporator saturation pressure and the condenser saturation pressure.

[0135] Steps S201 to S206, as illustrated in this embodiment, calculate the saturated gas-to-evaporator enthalpy based on the evaporator saturation temperature and the saturated liquid-to-condenser enthalpy based on the condenser saturation temperature. Then, based on these two enthalpies, the specific refrigerant capacity is calculated, accurately measuring the refrigeration capacity of the refrigerator. Next, the refrigerant mass flow rate is calculated based on the refrigeration capacity and the specific refrigerant capacity. Finally, the compressor flow coefficient is calculated based on the evaporator saturation temperature, evaporator saturation pressure, and refrigerant mass flow rate; the compressor pressure ratio is calculated based on the evaporator saturation pressure and condenser saturation pressure. This helps to understand the energy utilization rate of the centrifugal compressor and facilitates subsequent performance optimization based on the compressor flow coefficient and compressor pressure ratio.

[0136] When discussing compressor characteristics and efficiency, they are usually expressed as pressure ratio varying with the refrigerant flow coefficient, and efficiency varying with the flow coefficient. The flow coefficient depends on the compressor inlet conditions (evaporator saturation pressure). and evaporator saturation temperature Correct the refrigerant flow rate m.

[0137] For the same model of centrifugal compressor, without considering the influence of impeller shape, the flow coefficient is as shown in formula (1):

[0138] (1);

[0139] In formula (1), This is the saturation temperature of the evaporator, in degrees Celsius.

[0140] This is the saturation pressure of the evaporator, in kPa.

[0141] This is the mass flow rate of the refrigerant circulating in the compressor, expressed in kg / s.

[0142] Specifically, refrigerant mass flow rate For the specific calculation process, please refer to formula (2):

[0143] (2);

[0144] In formula (2), The cooling capacity of the refrigeration unit is expressed in kW.

[0145] This refers to the refrigeration capacity per unit refrigerant ratio, expressed in kJ / kg.

[0146] In some embodiments, the cooling capacity of the refrigeration mechanism It can be obtained by measuring using the thermal equilibrium method, which will not be elaborated here.

[0147] The unit refrigerant ratio cooling capacity It can be calculated using formula (3):

[0148] (3);

[0149] In formula (3), The specific enthalpy of the refrigerant in superheated gaseous state at the inlet of the guide vane under stagnation conditions is expressed in kJ / kg.

[0150] This represents the specific enthalpy of the refrigerant in its saturated liquid state at the throttle valve inlet, expressed in kJ / kg.

[0151] Specifically, the specific enthalpy of the superheated gaseous refrigerant at the inlet of the guide vane in a stagnant state. Approximately equal to the enthalpy of the saturated gas in the evaporator ,Right now Among them, the enthalpy of the saturated gas in the evaporator It can be calculated based on the evaporator saturation temperature.

[0152] Specifically, the enthalpy of the saturated gas in the evaporator The calculation formula is shown in formula (4):

[0153] (4);

[0154] in, , , , The fitting coefficients for the relationship between saturated gaseous specific enthalpy and saturation temperature are shown in Table 1 below:

[0155]

[0156] Table 1

[0157] It should be noted that the fitting coefficient for the relationship between saturated gaseous specific enthalpy and saturation temperature was obtained by fitting the thermophysical property data of refrigerant R134a.

[0158] Specific enthalpy of refrigerant in saturated liquid state at the throttle valve inlet Approximately equal to the specific enthalpy of the saturated liquid in the condenser ,Right now Among them, the enthalpy of the saturated liquid in the condenser It can be calculated based on the saturation temperature of the condenser.

[0159] Specifically, the enthalpy of the saturated liquid in the condenser The calculation formula is shown in formula (5):

[0160] (5);

[0161] in, This is the saturation temperature of the condenser. , , , The fitting coefficients for the relationship between the specific enthalpy of saturated liquid and saturation temperature are shown in Table 2 below:

[0162]

[0163] Table 2

[0164] It should be noted that the fitting coefficient for the relationship between saturated liquid specific enthalpy and saturation temperature is obtained by fitting the thermophysical property data of refrigerant R134a. In some embodiments, the compressor flow coefficient... It can be abbreviated as .

[0165] It should be noted that the subscripts evap and cond represent the evaporator and condenser, respectively.

[0166] In some embodiments, the condenser saturation pressure can be used as a reference. and evaporator saturation pressure ratio Determine the compressor pressure ratio under different conditions.

[0167] Among them, condenser saturation pressure It is based on the condenser saturation temperature The calculated saturation pressure of the evaporator is shown in formula (6). It is based on the evaporator saturation temperature The calculation is shown in formula (7):

[0168] (6);

[0169] (7);

[0170] in, , , , The fitting coefficients for the relationship between saturation pressure and saturation temperature are shown in Table 3 below:

[0171]

[0172] Table 3

[0173] It should be noted that the fitting coefficient for the relationship between saturated liquid specific enthalpy and saturation temperature was obtained by fitting the thermophysical property data of refrigerant R134a.

[0174] In some embodiments, the compressor pressure ratio Abbreviated as .

[0175] Depending on the location of the input power boundary, isentropic compression efficiency can be divided into compressor isentropic compression efficiency and compressor unit isentropic compression efficiency. The former refers to the mechanical work output by the compressor bearing, while the latter refers to the electrical work at the input end of the variable frequency starter cabinet.

[0176] Please see Figure 3 In some embodiments, step S105 may include, but is not limited to, steps S301 to S305:

[0177] Step S301: Calculate the compressor discharge enthalpy based on the compressor discharge temperature and condenser saturation pressure.

[0178] Step S302: Calculate the compressor specific shaft work per unit mass of refrigerant based on the saturated gas specific enthalpy of the evaporator and the discharge specific enthalpy of the compressor.

[0179] Step S303: Calculate the isentropic compression exhaust enthalpy based on the evaporator saturation pressure, evaporator saturation temperature, and condenser saturation pressure.

[0180] Step S304: Calculate the isentropic compression ratio shaft work per unit mass of refrigerant based on the enthalpy of the saturated gas phase in the evaporator and the enthalpy of the isentropic compression exhaust phase.

[0181] Step S305: Calculate the compressor's isentropic compression efficiency based on the compressor's specific shaft work and isentropic compression specific shaft work.

[0182] Steps S301 to S305, as illustrated in this embodiment, involve calculating the compressor discharge enthalpy based on the compressor discharge temperature and condenser saturation pressure, and then calculating the compressor specific shaft work per unit mass of refrigerant based on the evaporator saturated gas specific enthalpy and the compressor discharge enthalpy. The isentropic compression discharge temperature of the compressor is calculated based on the condenser saturation pressure, evaporator saturation pressure, and evaporator saturation temperature, further yielding the isentropic compression discharge enthalpy. The isentropic compression specific shaft work per unit mass of refrigerant is then calculated based on the evaporator saturated gas specific enthalpy and the isentropic compression specific shaft work. Finally, the compressor isentropic compression efficiency is calculated based on the compressor specific shaft work and the isentropic compression specific shaft work, allowing for accurate evaluation of compressor performance and facilitating subsequent performance optimization based on the compressor's isentropic compression efficiency.

[0183] For a single-stage compressor, the isentropic compression efficiency of the compressor is shown in formula (8):

[0184] (8);

[0185] In formula (8), The isentropic compression efficiency of the compressor.

[0186] This indicates specific work, measured in kJ / kg. Subscripts indicate the process of moving from one position to another.

[0187] Indicates the inlet state point from the guide vane. When the corresponding isentropic compression reaches the saturation pressure state point of the condenser. The isentropic compression ratio work is the isentropic compression ratio shaft work per unit mass of refrigerant, and its unit is kJ / kg;

[0188] The compressor specific shaft work, expressed as the amount of refrigerant per unit mass from the outlet of the inlet guide vane to the inlet of the diffuser, is measured in kJ / kg.

[0189] Specifically, isentropic compression ratio shaft work Compared to the shaft power of the compressor They are represented as follows:

[0190] (9);

[0191] (10);

[0192] It should be noted that the refrigerant passes through both the inlet guide vane and the diffuser in an adiabatic process; therefore, the enthalpy values ​​at the inlet and outlet of the inlet guide vane / diffuser are equal, which can be expressed as:

[0193] (11);

[0194] (12);

[0195] In formula (12), The diffuser exhaust enthalpy, also known as the compressor exhaust enthalpy, is a function of temperature and pressure. It can be obtained from the stagnation temperature and stagnation pressure at the diffuser outlet. The stagnation temperature at the diffuser outlet is obtained through measurement and is the same as the compressor exhaust temperature. The stagnation pressure at the diffuser outlet can be approximated by the condenser saturation pressure. Therefore, the compressor exhaust enthalpy, or diffuser exhaust enthalpy, can be calculated based on the measured compressor exhaust temperature and condenser saturation pressure.

[0196] Specifically, the formula for calculating the compressor exhaust enthalpy (diffuser exhaust enthalpy) is shown in formula (13):

[0197] (13);

[0198] (14);

[0199] (15);

[0200] in, , , , , , , The fitting coefficients for the relationship between the specific enthalpy of superheated steam and pressure and temperature are shown in Table 4 below:

[0201]

[0202] Table 4

[0203] It should be noted that the fitting coefficient of the relationship between superheated steam specific enthalpy and pressure and temperature was obtained by fitting the thermophysical property data of refrigerant R134a.

[0204] Therefore, formula (10) can be expressed as:

[0205] (16);

[0206] In formula (16), The diffuser exhaust gas specific enthalpy, i.e., the compressor exhaust gas specific enthalpy. The enthalpy of the saturated gas in the evaporator.

[0207] In formula (9), The enthalpy of the exhaust gas under isentropic compression iso ... It is calculated based on the condenser saturation pressure and isentropic compression exhaust temperature.

[0208] In some embodiments, the isentropic compression exhaust temperature can be calculated using the following formula:

[0209] (17);

[0210] (18);

[0211] (19);

[0212] The solution yields:

[0213] (20);

[0214] in, Since is the specific entropy, which is a function of pressure and temperature, the expressions of the above formulas (18) and (19) are similar to those of formula (21):

[0215] (twenty one);

[0216] (twenty two);

[0217] (twenty three);

[0218] (twenty four);

[0219] in, , , , , , ,

[0220] , , , , , ,

[0221] , , , , , The fitting coefficients for the relationship between superheated steam specific entropy and pressure and temperature are shown in Table 5 below:

[0222]

[0223] Table 5

[0224] The isentropic compression ratio shaft work per unit mass of refrigerant is calculated based on the enthalpy of the saturated gas phase in the evaporator and the enthalpy of the isentropic compression exhaust phase.

[0225] Finally, the isentropic compression ratio shaft work is calculated. Compared to the shaft power of the compressor Substitute into formula (8) for calculation to obtain the isentropic compression efficiency of the compressor.

[0226] In step S106 of some embodiments, for a single-stage centrifugal compressor system, the electrical power input to the frequency converter is used as the external input power, and the isentropic compression efficiency of the compressor system is expressed as:

[0227] (25);

[0228] in, The isentropic compression efficiency of the compressor unit. For isentropic compression ratio shaft work, The specific electrical power input to the inverter of the refrigeration unit is expressed in kJ / kg.

[0229] Among them, the specific power input to the inverter of the chiller For the specific calculation process, please refer to formula (26):

[0230] (26);

[0231] In formula (26), The electrical power input to the frequency converter in the electrical system is expressed in kW.

[0232] The compressor has a shaft work ratio It can be represented as:

[0233] (27);

[0234] In formula (27), For inverter efficiency, For motor efficiency, For bearing transmission efficiency.

[0235] Finally, formula (25) can be expressed as:

[0236] (28).

[0237] In step S107 of some embodiments, after calculating the compressor flow coefficient, compressor isentropic compression efficiency, and compressor group isentropic compression efficiency of the centrifugal compressor corresponding to numerous operating mode combinations, curves are constructed and fitted based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, compressor group isentropic compression efficiency, and pressure ratio, respectively, to obtain the following compressor performance curves:

[0238] Curves showing the pressure ratio versus compressor flow coefficient for different combinations of operating modes (inlet guide vane opening, compressor speed); where pressure ratio and compressor flow coefficient are used as a coordinate system, with pressure ratio as the Y-axis and compressor flow coefficient as the X-axis; see details [link to documentation]. Figure 4 , Figure 4 Examples of pressure ratio to compressor flow coefficient curves for different combinations of operating modes (inlet guide vane opening, compressor speed), where N represents compressor speed and IGV represents inlet guide vane opening;

[0239] Curves showing the compressor's isentropic compression efficiency versus its flow coefficient for different operating mode combinations (inlet guide vane opening, compressor speed); where the compressor's isentropic compression efficiency and flow coefficient are used as a coordinate system, with the compressor's isentropic compression efficiency as the Y-axis and the compressor's flow coefficient as the X-axis; see details [link to documentation]. Figure 5 , Figure 5 Examples of compressor isentropic compression efficiency versus compressor flow coefficient curves for different combinations of operating modes (inlet guide vane opening, compressor speed), where N represents compressor speed and IGV represents inlet guide vane opening;

[0240] Curves showing the isentropic compression efficiency versus compressor flow coefficient for different operating mode combinations (inlet guide vane opening, compressor speed); where the isentropic compression efficiency and compressor flow coefficient are used as a coordinate system, with the isentropic compression efficiency as the Y-axis and the compressor flow coefficient as the X-axis; see details [link to documentation]. Figure 6 , Figure 6 The curves represent the isentropic compression efficiency versus compressor flow coefficient for compressor units with different operating mode combinations (inlet guide vane opening and compressor speed), where N represents compressor speed and IGV represents inlet guide vane opening.

[0241] Understandably, compressor performance curves visually demonstrate the changes in pressure ratio and compression efficiency under different compressor flow coefficients. They are normalized and independent of compressor inlet parameters, including inlet pressure, temperature, and gas type, providing operators with a clear reference. Operators can quickly adjust compressor operating parameters based on the performance curves, ensuring the compressor always operates within its optimal performance range, thereby improving production efficiency and product quality. For example, by observing the performance curves, it can be discovered that the compressor unit achieves the highest isentropic compression efficiency within a certain range of flow coefficients, allowing the compressor to be adjusted to operate within that flow range.

[0242] After determining the compressor performance curve of the centrifuge using the above-mentioned method for determining centrifugal compressor performance data, the performance optimization of the compressor during actual use can be guided.

[0243] Next, the centrifugal compressor performance optimization method in the embodiments of this application will be described.

[0244] Figure 7 This is an optional flowchart of the centrifugal compressor performance optimization method provided in the embodiments of this application. Figure 7 The method may include, but is not limited to, steps S701 to S704.

[0245] Step S701: Obtain the current operating parameters of the target centrifugal compressor;

[0246] Step S702: Obtain the baseline performance curve of the target centrifugal compressor;

[0247] Step S703: Based on the current operating parameters and the benchmark performance curve, confirm the parameters to obtain the target optimization parameters;

[0248] Step S704: Optimize the performance of the target centrifugal compressor based on the target optimization parameters.

[0249] Steps S701 to S704, as illustrated in this embodiment, involve acquiring the current operating parameters of the target centrifugal compressor and its baseline performance curve. This allows for parameter confirmation based on the current operating parameters and the baseline performance curve, resulting in target optimization parameters and identifying the optimal adjustment direction. Finally, performance optimization of the target centrifugal compressor based on these optimization parameters enables precise and efficient improvement of its performance, ensuring stable and efficient operation.

[0250] In step S701 of some embodiments, the target centrifugal compressor refers to a specific centrifugal compressor device that needs to be monitored and its performance optimized. Current operating parameters are data reflecting the target centrifugal compressor's current operating state.

[0251] The current operating parameters include the current guide vane opening and the current rotational speed. The current guide vane opening affects the gas flow rate into the compressor, while the current rotational speed determines the compressor's work capacity and efficiency.

[0252] In addition to the current guide vane opening and current speed, the current operating parameters may also include, but are not limited to, evaporator parameters, condenser parameters, refrigeration capacity of the refrigeration unit, and unit operating efficiency parameters.

[0253] In step S702 of some embodiments, the baseline performance curve is obtained by the centrifugal compressor performance data determination method provided in the embodiments of this application, and the performance curve is constructed by calling the embodiments shown in steps S101 to S107, S201 to S205, and S301 to S305 above.

[0254] The benchmark performance curves include, but are not limited to:

[0255] First reference curve: The pressure ratio ~ compressor flow coefficient curve for different combinations of operating modes (inlet guide vane opening, compressor speed);

[0256] Second reference curve: The isentropic compression efficiency of the compressor versus the compressor flow coefficient for different combinations of operating modes (inlet guide vane opening, compressor speed);

[0257] The third baseline curve is the curve of isentropic compression efficiency versus compressor flow coefficient for compressor units with different combinations of operating modes (inlet guide vane opening, compressor speed).

[0258] Please see Figure 8 In some embodiments, step S703 may also include, but is not limited to, steps S801 to S803:

[0259] Step S801: Based on the current guide vane opening and the current rotational speed, a combination of current modes is obtained;

[0260] Step S802: Based on the current mode combination, the benchmark performance curve is filtered to obtain the target performance curve;

[0261] Step S803: Query the optimal value based on the target performance curve to obtain the target optimization parameters.

[0262] Steps S801 to S803, as illustrated in this embodiment, accurately locate the equipment's operating state by combining the current guide vane opening and current rotational speed, thus obtaining the current mode combination. Next, the baseline performance curve is filtered based on the current mode combination to obtain the target performance curve, eliminating interference from irrelevant curves. Finally, the optimal value is queried based on the target performance curve to obtain the target optimization parameters, thereby quickly and accurately finding the optimal parameters suitable for the current operating state, improving equipment operating efficiency and performance.

[0263] In step S801 of some embodiments, the current guide vane opening and the current rotational speed are combined to obtain the current mode combination as [current rotational speed, current guide vane opening].

[0264] For example, the current mode combination can be [38.5Hz, 75%], which means that the inlet guide vane opening is 75% and the compressor speed is the operating speed of the compressor when the power frequency is 38.5Hz.

[0265] In step S802 of some embodiments, the baseline performance curves are filtered based on the current mode combination to obtain the best-matching performance curve, thus obtaining a first performance curve. Next, based on the first performance curve, performance curves with intersection points are identified from the baseline performance curves to obtain a second performance curve. Finally, the first and second performance curves are used as the target performance curves.

[0266] It should be noted that the intersection of the first performance curve and the second performance curve means that the operating mode corresponding to the first performance curve and the operating mode corresponding to the second performance curve can both meet the operating requirements of the intersection point. However, there are advantages and disadvantages to these two operating modes, and there is room for optimization.

[0267] Specifically, the target optimization parameters are obtained by querying the optimal value of the target performance curve based on the following strategy:

[0268] It is understandable that as the compressor flow coefficient decreases, the compressor's isentropic compression efficiency decreases; as the compressor flow coefficient decreases, the compressor unit's isentropic compression efficiency decreases. Therefore, it is necessary to avoid operating with a low compressor flow coefficient or operating at a low load rate, which requires increasing the compressor flow coefficient.

[0269] Reducing the opening of the inlet guide vanes increases refrigerant flow resistance, leading to increased compressor power. Conversely, reducing compressor speed and increasing the opening of the inlet guide vanes can achieve energy savings. Within the same pressure ratio range, when the compressor operates at similar speeds, adjusting the inlet guide vane opening can regulate the flow coefficient; a larger inlet guide vane opening results in a higher compressor flow coefficient.

[0270] Therefore, among the first and second performance curves, the mode corresponding to the curve with lower compressor speed and larger inlet guide vane opening is selected as the target operating mode.

[0271] Furthermore, the compressor speed and inlet guide vane opening corresponding to the target operating mode are the target optimization parameters.

[0272] In step S704 of some embodiments, the process of adjusting the inlet guide vane opening and compressor speed of the target centrifugal compressor by means of a control system or manual operation, based on the determined target optimization parameters, so that the performance indicators (such as efficiency, flow rate, pressure, etc.) of the target centrifugal compressor reach or approach the optimal state, can enable the centrifugal compressor to achieve better performance in actual operation, improve production efficiency, and reduce energy consumption.

[0273] Understandably, understanding the internal operating rules and characteristics of a refrigeration unit allows for better use, achieving higher efficiency and lower costs. As a core component of a refrigeration unit, it's essential to understand the operating performance curves of the centrifugal compressor. This enables users to adjust and control the refrigeration unit's operating parameters externally, such as the inlet guide vane opening and compressor speed. Furthermore, by utilizing external system parameters and combining them with the characteristics of both the compressor and the refrigeration unit, real-time optimization of compressor control strategies can achieve efficient and low-cost operation of the refrigeration unit.

[0274] In this embodiment, for the district cooling system, the refrigeration system is subject to large annual temperature variations and refrigeration load rate variations ranging from 0 to 100%. The operating conditions of the refrigeration system are wide, and each of the above parameters, such as compressor inlet temperature and pressure, flow rate and pressure ratio, inlet guide vane opening, and compressor speed, varies greatly throughout the year. The operating conditions are easy to achieve, and there is no need to build a test platform, which can greatly reduce research costs.

[0275] The centrifugal compressor performance data determination method and centrifugal compressor performance optimization method proposed in this application obtain curves of compressor pressure ratio, isentropic compression efficiency and other parameters as a function of flow coefficient by measuring the real-time operating parameters of the refrigeration unit. These curves include different inlet guide vane openings and different compressor speeds. They can be used to analyze the performance of centrifugal compressors and their impact on refrigeration efficiency, and can also be used to control the operation of the compressor through the refrigeration system.

[0276] Please see Figure 9 This application also provides a centrifugal compressor performance data determination device, which can implement the above-mentioned centrifugal compressor performance data determination method. The device includes:

[0277] The compressor operating parameter acquisition module 901 is used to acquire the original compressor operating parameters, including the inlet guide vane opening and the compressor speed.

[0278] The mode combination module 902 is used to combine the inlet guide vane opening and the compressor speed to obtain the operating mode combination;

[0279] The parameter grouping module 903 is used to group the original compressor operating parameters based on the combination of operating modes to obtain grouped operating parameters; among which, the grouped operating parameters include evaporator parameters, condenser parameters, refrigeration unit cooling capacity, compressor discharge parameters and unit operating efficiency parameters;

[0280] The flow coefficient calculation module 904 is used to calculate the flow coefficient based on the evaporator parameters, condenser parameters and refrigeration capacity of the refrigeration unit, and obtain the compressor flow coefficient and compressor pressure ratio.

[0281] The compressor efficiency calculation module 905 is used to calculate the compression efficiency based on the evaporator parameters, condenser parameters and compressor discharge parameters, and obtain the compressor isentropic compression efficiency.

[0282] The unit efficiency calculation module 906 is used to calculate the compressor unit's isentropic compression efficiency based on the unit's operating efficiency parameters and the compressor's isentropic compression efficiency.

[0283] The performance curve construction module 907 is used to construct curves based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency to obtain the compressor performance curve.

[0284] The specific implementation of the centrifugal compressor performance data determination device is basically the same as the specific implementation of the centrifugal compressor performance data determination method described above, and will not be repeated here.

[0285] Please see Figure 10 This application also provides a centrifugal compressor performance optimization device, which can implement the above-mentioned centrifugal compressor performance optimization method. The device includes:

[0286] The current operating parameter acquisition module 1001 is used to acquire the current operating parameters of the target centrifugal compressor;

[0287] The performance curve acquisition module 1002 is used to acquire the baseline performance curve of the target centrifugal compressor;

[0288] The parameter confirmation module 1003 is used to confirm parameters based on the current operating parameters and the benchmark performance curve to obtain the target optimization parameters.

[0289] The performance optimization module 1004 is used to optimize the performance of the target centrifugal compressor based on the target optimization parameters.

[0290] The specific implementation of the centrifugal compressor performance optimization device is basically the same as the specific implementation of the centrifugal compressor performance optimization method described above, and will not be repeated here.

[0291] 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 method for determining centrifugal compressor performance data or the method for optimizing centrifugal compressor performance. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0292] Please see Figure 11 , Figure 11 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0293] The processor 1101 can be implemented using a general-purpose CPU (Central Processing Unit), 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.

[0294] The memory 1102 can be implemented in the form of read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 1102 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 1102, and the processor 1101 calls and executes the centrifugal compressor performance data determination method or the centrifugal compressor performance optimization method of the embodiments of this application.

[0295] Input / output interface 1103 is used to implement information input and output;

[0296] The communication interface 1104 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.).

[0297] Bus 1105 transmits information between various components of the device (e.g., processor 1101, memory 1102, input / output interface 1103, and communication interface 1104);

[0298] The processor 1101, memory 1102, input / output interface 1103 and communication interface 1104 are connected to each other within the device via bus 1105.

[0299] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for determining centrifugal compressor performance data or the method for optimizing centrifugal compressor performance.

[0300] 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.

[0301] The centrifugal compressor performance data determination method and centrifugal compressor performance optimization method provided in this application obtain original compressor operating parameters, including inlet guide vane opening and compressor speed. These parameters are then combined to obtain operating mode combinations, comprehensively covering different compressor operating states. Next, the original compressor operating parameters are grouped based on the operating mode combinations to obtain grouped operating parameters, making data classification clearer and more reasonable, facilitating targeted analysis. These grouped operating parameters include evaporator parameters, condenser parameters, compressor discharge parameters, refrigeration unit cooling capacity, and unit operating efficiency parameters. Further, flow coefficients are calculated based on evaporator parameters, condenser parameters, and refrigeration unit cooling capacity to obtain the compressor flow coefficient and compressor pressure ratio, accurately quantifying the compressor flow characteristics. Based on the evaporator parameters, condenser parameters, and compressor discharge parameters, the compressor isentropic compression efficiency is obtained, accurately assessing the efficiency of the compressor compression process. Finally, based on the unit operating efficiency parameters and the compressor isentropic compression efficiency, the compressor unit isentropic compression efficiency is calculated, considering the overall efficiency of the compressor unit. Finally, based on the compressor flow coefficient, compressor pressure ratio, compressor isentropic compression efficiency, and compressor unit isentropic compression efficiency, curves are constructed to obtain compressor performance curves. These curves can intuitively, comprehensively, and accurately reflect the performance of the compressor under different operating modes, providing a strong basis for optimizing operation, improving energy efficiency, and ensuring stable equipment operation.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] The software tools or components not belonging to our company that appear in the embodiments of this application are for illustrative purposes only and do not represent actual use.

[0313] 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 determining the performance data of a centrifugal compressor, characterized in that, The method includes: Obtain the original compressor operating parameters; wherein, the original compressor operating parameters include the inlet guide vane opening degree and the compressor speed; By combining the inlet guide vane opening and the compressor speed, a combination of operating modes is obtained; The original compressor operating parameters are grouped based on the aforementioned operating mode combination to obtain grouped operating parameters; wherein, the grouped operating parameters include evaporator parameters, condenser parameters, refrigeration unit cooling capacity, compressor discharge parameters, and unit operating efficiency parameters; the refrigeration unit cooling capacity is obtained by measuring using a heat balance method; The flow coefficient is calculated based on the evaporator parameters, the condenser parameters, and the cooling capacity of the refrigeration unit to obtain the compressor flow coefficient and compressor pressure ratio. The compression efficiency is calculated based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters to obtain the compressor's isentropic compression efficiency. The isentropic compression efficiency of the compressor unit is calculated based on the unit operating efficiency parameters and the compressor isentropic compression efficiency. Based on the compressor flow coefficient, the compressor pressure ratio, the compressor isentropic compression efficiency, and the compressor group isentropic compression efficiency, curves are constructed to obtain compressor performance curves; wherein, the compressor performance curves include the pressure ratio to compressor flow coefficient curves, the compressor isentropic compression efficiency to compressor flow coefficient curves, and the compressor group isentropic compression efficiency to compressor flow coefficient curves for different operating mode combinations.

2. The method according to claim 1, characterized in that, The evaporator parameters include evaporator saturation temperature and evaporator saturation pressure, and the condenser parameters include condenser saturation temperature and condenser saturation pressure; the calculation of the flow coefficient based on the evaporator parameters, the condenser parameters, and the refrigeration capacity of the refrigeration unit to obtain the compressor flow coefficient and compressor pressure ratio includes: The saturated gas phase enthalpy of the evaporator is calculated based on the evaporator saturation temperature. The saturated liquid phase enthalpy of the condenser is calculated based on the condenser saturation temperature. The refrigeration capacity per unit refrigerant ratio is calculated based on the enthalpy of the saturated gas phase of the evaporator and the enthalpy of the saturated liquid phase of the condenser. The refrigerant mass flow rate is calculated based on the cooling capacity of the refrigeration mechanism and the cooling capacity per unit refrigerant ratio. The compressor flow coefficient is calculated based on the evaporator saturation temperature, the evaporator saturation pressure, and the refrigerant mass flow rate. The compressor pressure ratio is calculated based on the evaporator saturation pressure and the condenser saturation pressure.

3. The method according to claim 2, characterized in that, The compressor discharge parameters include the compressor discharge temperature; the compression efficiency is calculated based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters to obtain the compressor's isentropic compression efficiency, including: The compressor discharge enthalpy is calculated based on the compressor discharge temperature and the condenser saturation pressure. The compressor specific shaft work per unit mass of refrigerant is calculated based on the enthalpy of the saturated gas in the evaporator and the enthalpy of the compressor exhaust gas. The isentropic compression exhaust ratio enthalpy is calculated based on the evaporator saturation pressure, the evaporator saturation temperature, and the condenser saturation pressure. The isentropic compression ratio shaft work per unit mass of refrigerant is calculated based on the enthalpy of the saturated gas phase of the evaporator and the enthalpy of the isentropic compression exhaust phase. The isentropic compression efficiency of the compressor is obtained by calculating based on the compressor's specific shaft work and the isentropic compression specific shaft work.

4. The method according to claim 1, characterized in that, The process of grouping the original compressor operating parameters based on the operating mode combination to obtain grouped operating parameters includes: Based on the combination of operating modes, the original compressor operating parameters are grouped to obtain the initial compressor operating parameters; The initial compressor operating parameters are segmented to obtain segmented operating parameters; Stability screening is performed based on the sharding operation parameters to obtain the grouping operation parameters.

5. A method for optimizing the performance of a centrifugal compressor, characterized in that, The method includes: Obtain the current operating parameters of the target centrifugal compressor; the current operating parameters include the current guide vane opening and the current rotational speed; Obtain a reference performance curve for the target centrifugal compressor; wherein the reference performance curve is obtained by the centrifugal compressor performance data determination method according to any one of claims 1 to 4; The current mode combination is obtained by combining the current guide vane opening and the current rotation speed. The baseline performance curves are filtered based on the current mode combination to obtain the target performance curve; wherein, the target performance curve includes a first performance curve and a second performance curve; Based on the first performance curve and the second performance curve, the optimal value is queried to determine the target operating mode, and the parameters corresponding to the target operating mode are used as target optimization parameters; wherein, the target optimization parameters include compressor speed and inlet guide vane opening. The performance of the target centrifugal compressor is optimized based on the compressor speed and the inlet guide vane opening.

6. A device for determining the performance data of a centrifugal compressor, characterized in that, The device includes: The compressor operating parameter acquisition module is used to acquire raw compressor operating parameters, including inlet guide vane opening and compressor speed. The mode combination module is used to combine the inlet guide vane opening and the compressor speed to obtain the operating mode combination; The parameter grouping module is used to group the original compressor operating parameters based on the operating mode combination to obtain grouped operating parameters; wherein, the grouped operating parameters include evaporator parameters, condenser parameters, refrigeration unit cooling capacity, compressor discharge parameters, and unit operating efficiency parameters; the refrigeration unit cooling capacity is obtained by measuring using a heat balance method; The flow coefficient calculation module is used to calculate the flow coefficient based on the evaporator parameters, the condenser parameters and the refrigeration capacity of the refrigeration unit, so as to obtain the compressor flow coefficient and the compressor pressure ratio. The compressor efficiency calculation module is used to calculate the compression efficiency based on the evaporator parameters, the condenser parameters, and the compressor discharge parameters, and obtain the compressor isentropic compression efficiency. The unit efficiency calculation module is used to calculate the compressor unit's isentropic compression efficiency based on the unit's operating efficiency parameters and the compressor's isentropic compression efficiency. The performance curve construction module is used to construct curves based on the compressor flow coefficient, the compressor pressure ratio, the compressor isentropic compression efficiency, and the compressor group isentropic compression efficiency to obtain the compressor performance curve; wherein, the compressor performance curve includes the pressure ratio to compressor flow coefficient curve, the compressor isentropic compression efficiency to compressor flow coefficient curve, and the compressor group isentropic compression efficiency to compressor flow coefficient curve for different operating mode combinations.

7. A centrifugal compressor performance optimization device, characterized in that, The device includes: The current operating parameter acquisition module is used to acquire the current operating parameters of the target centrifugal compressor; the current operating parameters include the current guide vane opening and the current rotational speed; A performance curve acquisition module is used to acquire a reference performance curve of the target centrifugal compressor; wherein the reference performance curve is obtained by the centrifugal compressor performance data determination method according to any one of claims 1 to 4; The optimization parameter confirmation module is used to combine the current guide vane opening and the current rotational speed to obtain the current mode combination; The baseline performance curves are filtered based on the current mode combination to obtain the target performance curve; wherein, the target performance curve includes a first performance curve and a second performance curve; Based on the first performance curve and the second performance curve, the optimal value is queried to determine the target operating mode, and the parameters corresponding to the target operating mode are used as target optimization parameters; wherein, the target optimization parameters include compressor speed and inlet guide vane opening. The performance optimization module is used to optimize the performance of the target centrifugal compressor based on the compressor speed and the inlet guide vane opening.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the centrifugal compressor performance data determination method according to any one of claims 1 to 4, or the centrifugal compressor performance optimization method according to claim 5.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the centrifugal compressor performance data determination method according to any one of claims 1 to 4, or the centrifugal compressor performance optimization method according to claim 5.

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