Compressor control system and control method

Abstract

The present application discloses a system and method for controlling a compressor in a refrigeration system. [Solution] A refrigeration system includes a compressor and an economizer, the compressor including a slide valve, and the economizer including an inlet pipe, a gas outlet pipe, and a liquid outlet pipe. The compressor control system includes an inlet pipe sensor, a gas outlet pipe sensor, a liquid outlet pipe sensor, and a controller configured to receive pressure and temperature parameters from the inlet pipe, the gas outlet pipe, and the liquid outlet pipe, and to control the movement of the slide valve based on the pressure and temperature parameters to adjust the position of the slide valve. In this application, changes in the actual internal volume ratio of the compressor reflect changes in the mass and density of the refrigerant discharged from the compressor's exhaust port. Because the effects of economizer pipe design and pressure drop are avoided, the calibration results of the compressor's internal volume ratio are more accurate and reliable.

Description

[Technical Field]

[0001] The present application relates to the field of refrigeration systems, and more particularly to a compressor control system and method in a refrigeration system. [Background technology]

[0002] Screw compressors are commonly used components in refrigeration systems. In a screw compressor, the tooth gap volumes of a pair of screw rotors interlock with each other, changing the basic volume of the tooth space, completing the processes of gas intake, compression, and exhaust. The internal volume ratio Vi (Vi = Vs / Vd) is an important operating parameter of a screw compressor, where Vs represents the volume of the rotor intake chamber and Vd represents the volume of the rotor exhaust chamber. The size of the rotor exhaust chamber volume can be adjusted by adjusting the position of the slide valve, thereby adjusting the internal volume ratio Vi.

[0003] According to different operating conditions of the refrigeration system, the system will have different external volume ratio Vi sys The internal volume ratio of the compressor, Vi, is the external volume ratio of the refrigeration system, Vi sys This allows the compressor rotor exhaust pressure to match the refrigeration system discharge pressure, thereby avoiding additional power consumption caused by over-compression or under-compression and ensuring the compressor operates at optimum efficiency. Summary of the Invention

[0004] At least one object of a first aspect of the present application is to provide a compressor control system in a refrigeration system including a compressor and an economizer, wherein the compressor includes a slide valve, and the economizer is provided with an inlet pipe, a gas outlet pipe, and a liquid outlet pipe, and the compressor control system includes an inlet pipe sensor that detects pressure parameters and temperature parameters of the inlet pipe, a gas outlet pipe sensor that detects pressure parameters and temperature parameters of the gas outlet pipe, a liquid outlet pipe sensor that detects pressure parameters and temperature parameters of the liquid outlet pipe, and a control device configured to receive the pressure parameters and temperature parameters of the inlet pipe, the gas outlet pipe, and the liquid outlet pipe, and to control movement of the slide valve based on the pressure parameters and temperature parameters to adjust the position of the slide valve.

[0005] According to the first aspect, the inlet pipe sensor includes an inlet pipe pressure sensor and an inlet pipe temperature sensor, which are configured to detect pressure parameters and temperature parameters of the inlet pipe, respectively; the gas outlet pipe sensor includes a gas outlet pipe pressure sensor and a gas outlet pipe temperature sensor, which are configured to detect pressure parameters and temperature parameters of the gas outlet pipe, respectively; and the liquid outlet pipe sensor includes a liquid outlet pipe pressure sensor and a liquid outlet pipe temperature sensor, which are configured to detect pressure parameters and temperature parameters of the liquid outlet pipe, respectively.

[0006] According to the first aspect, the refrigeration system has an external volume ratio Vi sys the compressor has an internal volume ratio Vi, the slide valve is used to adjust the internal volume ratio Vi of the compressor, the control device receives individual pressure parameters and individual temperature parameters of the inlet piping, the gas outlet piping and the liquid outlet piping, calculates a calibration coefficient A of the compressor based on the individual pressure parameters and the individual temperature parameters, and adjusts the external volume ratio Vi sysand configured to calculate an internal volume ratio Vi of the compressor according to the calibration coefficient A, and adjust the position of the slide valve according to the internal volume ratio Vi.

[0007] According to the first aspect, the compressor further includes a drive device, the drive device being communicatively connected to the control device, the slide valve having a first position corresponding to a minimum internal volume ratio of the compressor and a second position corresponding to a maximum internal volume ratio of the compressor, and the drive device being configured to drive the slide valve to move between the first position and the second position to adjust the internal volume ratio of the compressor.

[0008] According to the first aspect, the compressor is provided with an intake pipe and an exhaust pipe, and the compressor control system further includes an intake pressure sensor and an exhaust pressure sensor, the intake pressure sensor is configured to detect a pressure parameter of the intake pipe, and the exhaust pressure sensor is configured to detect a pressure parameter of the exhaust pipe, and the control device determines an external volume ratio Vi based on the pressure parameter of the intake pipe and the pressure parameter of the exhaust pipe. sys The method is configured to calculate:

[0009] According to the first aspect, calculating the calibration factor A of the compressor based on the individual pressure parameters and the individual temperature parameters includes: calculating an enthalpy value H1 of the inlet refrigerant in the inlet pipe according to the pressure parameter and the temperature parameter of the inlet pipe; calculating an enthalpy value H2 of the liquid refrigerant in the liquid outlet pipe according to the pressure parameter and the temperature parameter of the liquid outlet pipe; calculating an enthalpy value H3 of the gas refrigerant in the gas outlet pipe according to the pressure parameter and the temperature parameter of the gas outlet pipe; and obtaining the calibration factor A according to the following formula: A=(H1-H2) / (H3-H1).

[0010] According to the first aspect, the control device calculates the voltage V i by the following equation: V i =V i sys / (1+A) to calculate the internal volume ratio Vi.

[0011] At least one object of a second aspect of the present application is to provide a control method for a compressor control system in a refrigeration system, the refrigeration system including a compressor and an economizer, the compressor including a slide valve, and the economizer provided with an inlet pipe, a gas outlet pipe, and a liquid outlet pipe, the control method including steps of receiving pressure parameters and temperature parameters of the inlet pipe, the gas outlet pipe, and the liquid outlet pipe, and controlling movement of the slide valve based on the individual pressure parameters and the individual temperatures, and adjusting the position of the slide valve.

[0012] According to the second aspect, the refrigeration system has an external volume ratio Vi sys and the compressor has an internal volume ratio Vi, and the slide valve is used to control the internal volume ratio Vi of the compressor, and the control of the movement of the slide valve based on the individual pressure parameters and the individual temperature parameters includes calculating a calibration factor A of the compressor based on the individual pressure parameters and the individual temperature parameters, and calculating an external volume ratio Vi sys and calculating an internal volume ratio Vi of the compressor according to a calibration coefficient A; and adjusting the position of the slide valve according to the internal volume ratio Vi.

[0013] According to the second aspect, the compressor is provided with an intake pipe and an exhaust pipe, and an external volume ratio Vi sys is calculated based on the intake manifold pressure parameter and the exhaust manifold pressure parameter.

[0014] According to the second aspect, the enthalpy value H1 of the inlet refrigerant in the inlet pipe is calculated according to the pressure and temperature parameters of the inlet pipe, the enthalpy value H2 of the liquid refrigerant in the liquid outlet pipe is calculated according to the pressure and temperature parameters of the liquid outlet pipe, and the enthalpy value H3 of the gas refrigerant in the gas outlet pipe is calculated according to the pressure and temperature parameters of the gas outlet pipe, and the calibration coefficient A is calculated according to the following formula: A=(H1-H2) / (H3-H1).

[0015] According to the second aspect, the internal volume ratio Vi is calculated by the following formula: Vi=Visys It is calculated according to / (1+A).

[0016] Other features, advantages, and embodiments of the present application will be described or become apparent from consideration of the following detailed description, the accompanying drawings, and the claims. Furthermore, it should be understood that the above summary of the invention and the following specific embodiments are all exemplary and are intended to provide further explanation rather than limit the scope of the application as claimed. However, the detailed description and specific examples represent only preferred embodiments of the application. Various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a structural schematic diagram of a refrigeration system according to an embodiment of the present application; [Figure 2A] FIG. 2 is a structural schematic diagram of the compressor when the slide valve is in a first position. [Figure 2B] FIG. 4 is a structural schematic diagram of the compressor when the slide valve is in a second position. [Figure 3A] FIG. 2 is a structural block diagram of a control device. [Figure 3B] FIG. 2 is a structural block diagram of a control device. [Figure 3C] FIG. 2 is a structural block diagram of a control device. [Figure 4A] 10 is a flowchart of a control method. [Figure 4B] 10 is a flowchart of a control method. [Figure 4C] 10 is a flowchart of a control method. DETAILED DESCRIPTION OF THE INVENTION

[0018] Various specific embodiments of the present application will now be described with reference to the accompanying drawings, which form a part of this specification. Although directional terms such as "front," "rear," "upper," "lower," "left," "right," "top," and "bottom" are used herein to describe various exemplary structural parts and elements of the present application, it should be understood that these terms, as used herein, are determined solely based on the exemplary directions shown in the accompanying drawings for ease of description. Because the embodiments disclosed in the present application may be oriented in different directions, these directional terms are for illustrative purposes only and should not be considered limiting.

[0019] 1 shows a structural schematic diagram of a refrigeration system 110 according to the present application. As shown in Fig. 1, the refrigeration system 110 includes a compressor 100, a condenser 101, an economizer 103, a throttling device 104, and an evaporator 102, which are fluidly connected in sequence.

[0020] The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 107 of the compressor 100 enters the condenser 101, where it releases heat and condenses into liquid refrigerant, and then enters the economizer 103. In the economizer 103, a portion of the liquid refrigerant exchanges heat with another portion of the liquid refrigerant. A portion of the liquid refrigerant evaporates into gaseous refrigerant and returns to the compressor 100, while the other portion of the liquid refrigerant is cooled into subcooled liquid refrigerant and enters the throttle device 104, where it is throttled into low-pressure two-phase refrigerant and enters the evaporator 102, where it absorbs heat and evaporates into gaseous refrigerant, finally returning to the compressor 100 from the suction port 106 of the compressor 100, completing the refrigerant circulation.

[0021] The refrigeration system 110 further includes a compressor control system, which includes a controller 120. The compressor control system is used to control the internal volume ratio of the compressor, so that the pressure in the rotor exhaust chamber of the compressor (i.e., the internal pressure) matches the exhaust pressure of the refrigeration system (i.e., the external pressure), and avoid over-compression or under-compression. By adjusting the internal volume ratio of the compressor in real time according to the operating conditions of the refrigeration system 110, the operating efficiency of the refrigeration system can be improved and energy consumption can be reduced.

[0022] In the refrigeration system 110 equipped with the economizer 103 of the present application, the change in the internal volume ratio Vi of the compressor is reflected by utilizing the change in the density of the refrigerant gas in the exhaust chamber of the compressor 100, and the calibration coefficient A is calculated by utilizing the law of conservation of energy in the heat exchange of the economizer, so that the internal volume ratio Vi can be calibrated to the equivalent internal volume ratio Vi*. Next, the control device 120 converts the equivalent internal volume ratio Vi* into the external volume ratio Vi of the refrigeration system. sys and then the external volume ratio Vi of the refrigeration system 110 sys and the calibration factor A, the actual internal volume ratio Vi of the compressor 100 is inversely estimated, and finally, the position of the slide valve 232 (see FIGS. 2A and 2B) of the compressor is adjusted based on the actual internal volume ratio Vi so that the pressure in the rotor exhaust chamber of the compressor 100 matches the discharge pressure of the refrigeration system 110, thereby avoiding the occurrence of over-compression or under-compression situations.

[0023] Specifically, the compressor control system includes a suction pressure sensor 127 and a discharge pressure sensor 128. The suction pressure sensor 127 is provided in the suction pipe 111 between the suction port 106 of the compressor 100 and the evaporator 102, and the discharge pressure sensor 128 is provided in the discharge pipe 112 between the discharge port 107 of the compressor 100 and the condenser 101. The suction pressure sensor 127 and the discharge pressure sensor 128 are communicatively connected to the control device 120 and are used to detect the suction pressure Ps of the suction pipe 111 and the discharge pressure Pd of the discharge pipe 112 and acquire the respective pressure parameters. Based on the suction pressure Ps and the discharge pressure Pd, the external volume ratio Vi of the refrigeration system is calculated. syscan be calculated.

[0024] The economizer 103 is in fluid communication with the condenser 101 via an inlet pipe 113, with the gas refill port 108 of the compressor 100 via a gas outlet pipe 114, and with the throttling device 104 via a liquid outlet pipe 115. The compressor control system further includes an inlet pipe sensor, a gas outlet pipe sensor, and a liquid outlet pipe sensor. These sensors are also communicatively connected to the controller 120. The inlet pipe sensor is provided on the inlet pipe 113 and is used to detect the pressure and temperature in the inlet pipe 113 and obtain the respective pressure and temperature parameters. In this embodiment, the inlet pipe sensors include an inlet pipe pressure sensor 122 and an inlet pipe temperature sensor 121. The gas outlet pipe sensor is provided on the gas outlet pipe 114 and is used to detect the pressure and temperature in the gas outlet pipe 114 and obtain the respective pressure and temperature parameters. In this embodiment, the gas outlet pipe sensors include a gas outlet pipe pressure sensor 124 and a gas outlet pipe temperature sensor 123. The liquid outlet pipe sensor is provided in the liquid outlet pipe 115 and is used to detect the pressure and temperature in the liquid outlet pipe 115 and acquire the respective pressure parameters and temperature parameters. In this embodiment, the liquid outlet pipe sensor includes a liquid outlet pipe pressure sensor 126 and a liquid outlet pipe temperature sensor 125.

[0025] By detecting the pressure and temperature in each pipe of the economizer 103, it is possible to obtain an enthalpy value H1 of the inlet refrigerant entering the economizer 103 through the inlet pipe 113, an enthalpy value H2 of the liquid refrigerant exiting the economizer 103 through the liquid outlet pipe 115, and an enthalpy value H3 of the gas refrigerant exiting the economizer 103 through the gas outlet pipe 114. A calibration factor A can be calculated based on the inlet refrigerant enthalpy value H1, the liquid refrigerant enthalpy value H2, and the gas refrigerant enthalpy value H3. The calibration factor A reflects the change in density of the compressor discharge chamber caused by the economizer gas refill.

[0026] The internal volume ratio of the compressor is the external volume ratio Vi of the refrigeration system. sys Vi = Vi by back-calculating based on the compressor calibration factor A. sys ×(1+A). A specific calculation method will be described in detail with reference to Figures 2A and 2B.

[0027] 2A and 2B show schematic diagrams of the compressor, with FIG. 2A showing the state when the slide valve is in a first position and FIG. 2B showing the state when the slide valve is in a second position. As shown in FIGS. 2A and 2B, the compressor 100 includes a suction chamber 236, a discharge chamber 237, and a compression chamber 231. The suction chamber 236 is fluidly connected to the suction pipe 111 via the suction port 106, and the discharge chamber 237 is fluidly connected to the discharge pipe 112 via the discharge port 107. The compression chamber 231 is formed by the tooth grooves of the pair of screw rotors and is fluidly connected to the suction chamber 236 and the discharge chamber 237. The gas replenishment port 108 is fluidly connected to the compression chamber 231. Therefore, the refrigerant in the suction pipe 111 can enter the suction chamber 236 through the suction port 106 and then enter the compression chamber 231 and be compressed. In addition, the refrigerant in the gas outlet pipe 114 can also flow into the compression chamber 231 through the gas refill port 108 and be compressed. After being fully compressed, the two parts of the refrigerant enter the exhaust chamber 237 together and finally discharge into the exhaust pipe 112 through the exhaust port 107, completing the compression process of the compressor 100.

[0028] The compressor 100 further includes a slide valve 232 and a drive device 233. The drive device 233 is mechanically connected to the slide valve 232 and drives the slide valve 232 to move. The drive device 233 is also communicatively connected to the control device 120. The slide valve 232 has a first position corresponding to the minimum internal volume ratio of the compressor 100 and a second position corresponding to the maximum internal volume ratio of the compressor 100. Specifically, when the slide valve 232 is moved to the leftmost position (i.e., the first position) as shown in FIG. 2A , the exhaust chamber volume of the exhaust chamber 237 is maximized, and therefore the internal volume ratio is minimized. When the slide valve 232 is moved to the rightmost position (i.e., the second position) as shown in FIG. 2B , the exhaust chamber volume of the exhaust chamber 237 is minimized, and therefore the internal volume ratio is maximized. The drive device 233 is used to move the slide valve 232 between a first position and a second position to adjust the volume of the exhaust chamber 237 and adjust the internal volume ratio Vi of the compressor 100. It should be understood by those skilled in the art that the drive device 233 may include a position sensor (not shown) that is used to detect the position of the slide valve 232 in order to control the movement position of the slide valve 232.

[0029] Compared to a refrigeration system without an economizer, even if the system operating conditions and the position of the slide valve 232 remain unchanged, the refrigerant entering the compression chamber 231 from the gas refill port 108 also changes the actual internal volume ratio of the compressor 100. Therefore, changing the position of the slide valve 232 to change the external volume ratio Vi of the refrigeration system 110 is sys , the actual internal volume ratio Vi of the compressor 100 is adjusted directly according to the external volume ratio Vi of the refrigeration system 110. sys will no longer match.

[0030] In the compressor control system of the present application, the calibrated equivalent internal volume ratio Vi* is sysThen, the internal volume ratio Vi of the compressor is obtained by back-calculating according to the compressor calibration factor A, and the position of the slide valve 232 is adjusted according to the internal volume ratio Vi, so that the actual internal volume ratio of the compressor 100 is adjusted to the external volume ratio Vi of the refrigeration system 110. sys matches.

[0031] More specifically, the external volume ratio of the refrigeration system is Vi sys =(Pd / Ps)^(1 / k), where k is the adiabatic index of the refrigerant at the suction port of the compressor.

[0032] The equivalent internal volume ratio of the compressor 100 is Vi*=ρd* / ρs, where ρd* represents the discharge density of the compressor and ρs represents the suction density of the compressor.

[0033] On the other hand, ρs = m2 / Vs, and ρd* = (m2 + m3) / Vd. Here, m2 is the mass of liquid refrigerant flowing out from the liquid outlet piping 115, i.e., the gas suction volume of the compressor, and m3 is the mass of gas refrigerant flowing out from the economizer gas outlet piping 114, i.e., the gas replenishment volume of the economizer. Vs is the volume of the suction chamber, and Vd is the volume of the exhaust chamber. Therefore, the calibration formula for the internal volume ratio Vi of the compressor can be obtained. That is, the relationship between the equivalent internal volume ratio Vi* and the internal volume ratio Vi of the compressor is Vi* = [(m2 + m3) / m2] × Vi.

[0034] The controller 120 calculates the equivalent internal volume ratio Vi* of the compressor 100 in relation to the external volume ratio Vi sys Set it to match the Vi sys =Vi*=[(m2+m3) / m2]×Vi. Therefore, by back calculation, Vi=Vi sys ×[m2 / (m2+m3)] is obtained.

[0035] Furthermore, the refrigerant entering the economizer 103 from the inlet pipe 113 exchanges heat within the economizer 103, and therefore, according to the law of conservation of thermal energy of the economizer, m3 × (H3 − H1) = m2 × (H1 − H2) is satisfied, where m1 represents the total mass of the inlet refrigerant entering the economizer 103 from the inlet pipe 113.

[0036] Therefore, Vi sys = [(m2 + m3) / m2] × Vi = (1 + m3 / m2) × Vi = (1 + A) × Vi. The compressor calibration coefficient is A = (H1 - H2) / (H3 - H1).

[0037] Therefore, the internal volume ratio of the compressor is equal to the external volume ratio Vi of the refrigeration system. sys and the compressor calibration factor A, Vi = Vi sys It can be calculated as / (1+A).

[0038] 3A-3C are structural block diagrams of the control device 120. As shown in FIG. 3A, the control device 120 includes a bus 341, a processor 342, an input interface 343, an output interface 344, and a memory 345 having a control program 346. The individual components within the control device 120, including the processor 342, the input interface 343, the output interface 344, and the memory 345, are communicatively connected to the bus 341, and the processor 342 can control the operation of the input interface 343, the output interface 344, and the memory 345. Specifically, the memory 345 is configured to store programs, instructions, and data, and the processor 342 can read programs, instructions, and data from the memory 345 and write data to the memory 345. By executing the programs and instructions read from the memory 345, the processor 342 controls the operation of the input interface 343 and the output interface 344.

[0039] 3A-3C , the input interface 343 is communicatively connected to the inlet pipe temperature sensor 121 and the inlet pipe pressure sensor 122, the gas outlet pipe temperature sensor 123 and the gas outlet pipe pressure sensor 124, the liquid outlet pipe temperature sensor 125 and the liquid outlet pipe pressure sensor 126, and the suction pressure sensor 127 and the exhaust pressure sensor 128 via connection 347 to receive pressure and / or temperature parameters from the individual sensors and store these pressure and / or temperature parameters in memory 345. The output interface 344 is communicatively connected to the drive device 233 of the compressor 100 via connection 348. The control device 120 executes a program 346 in the memory 345 to control the drive device 233 and thereby the position of the slide valve 232.

[0040] 4A to 4C are flowcharts of a control method for the compressor control system.

[0041] In step 450, the program begins.

[0042] In step 451, the controller 120 executes step 452 to determine the external volume ratio Vi of the refrigeration system. sys and execute step 453 to obtain the compressor calibration factor A.

[0043] In step 454, the control device 120 calculates the obtained external volume ratio Vi sys Based on the and calibration factor A, calculate the internal volume ratio Vi of the compressor.

[0044] In step 455, the control device 120 controls the movement of the drive device 233 in accordance with the magnitude of the internal volume ratio Vi, and adjusts the position of the slide valve 232.

[0045] In step 456, the controller 120 determines whether the refrigeration system 110 has finished operating. If the refrigeration system 110 has finished operating, the controller 120 executes step 457. If the refrigeration system 110 has not finished operating, the controller 120 returns to step 451.

[0046] In step 457 the program ends.

[0047] Step 452 includes steps 461 and 462. In step 461, controller 120 receives pressure parameters of intake pressure sensor 127 and exhaust pressure sensor 128.

[0048] In step 462, the controller 120 calculates the external volume ratio Vi sys is obtained by calculation.

[0049] Step 453 includes step 464, step 465, and step 466. In step 464, controller 120 receives pressure and temperature parameters from inlet line temperature sensor 121 and inlet line pressure sensor 122, gas outlet line temperature sensor 123 and gas outlet line pressure sensor 124, and liquid outlet line temperature sensor 125 and liquid outlet line pressure sensor 126.

[0050] In step 465, the controller 120 calculates the enthalpy value of the refrigerant in the inlet line 113, H1, the enthalpy value of the refrigerant in the liquid outlet line 115, H2, and the enthalpy value of the refrigerant in the gas outlet line 114, H3.

[0051] In step 466, the controller 120 obtains the calibration factor A by calculation.

[0052] In a refrigeration system without an economizer, the pressure in the rotor discharge chamber of the compressor can be matched to the discharge pressure of the refrigeration system by matching the internal volume ratio of the compressor with the external volume ratio of the refrigeration system. However, in a refrigeration system with an economizer, the refrigerant discharged from the exhaust port 107 includes refrigerant drawn through the gas replenishment port 108 in addition to refrigerant drawn through the suction port 106. Therefore, compared to a refrigeration system without an economizer, if the compressor slide valve is in the same position and the system operating conditions and suction pressure are the same, the volume of the refrigerant discharged from the exhaust port 107 remains the same, but its mass and density increase. As a result, the pressure in the rotor discharge chamber of the compressor becomes higher than the discharge pressure of the refrigeration system, resulting in undesirable overcompression of the refrigeration system.

[0053] External volume ratio Vi of the refrigeration system sys If the method of replacing the economizer gas outlet pressure with the refrigeration system suction pressure Ps is used to calibrate, the position of the compressor slider is determined by the internal volume ratio Vi of the compressor being calibrated to the external volume ratio Vi. sys Such a calibration method that uses pressure displacement to account for the effects of the economizer is highly sensitive to piping design and piping pressure drop, resulting in inaccurate calibration results.

[0054] In this application, the internal volume ratio Vi of the compressor is determined by the external volume ratio Vi of the system depending on the changes in the mass and density of the refrigerant discharged from the compressor discharge port and the operating conditions of the economizer. sys The calibration results are more accurate and reliable. The calibration method of the present application is related only to the enthalpy values in the individual connecting piping of the economizer, and is independent of the piping design and piping pressure drop, thereby avoiding the influence of pressure drop. According to the calibration results, the compressor control system of the present application can adjust the external volume ratio Vi of the system during operation of the refrigeration system. sys The internal volume ratio Vi of the compressor can be adjusted in real time according to the demand, thereby improving the working efficiency of the refrigeration system and reducing energy consumption.

[0055] Furthermore, in this application, there is no need to directly detect mass or pressure when calculating the calibration factor A. Instead, the calibration factor A is obtained by converting the mass ratio into an enthalpy value. This calculation method is simpler and more accurate.

[0056] Furthermore, the compressor control system of the present application is also suitable for controlling compressors with multiple gas refill ports, since it only needs to calculate enthalpy values at the inlet and individual outlets of the economizer.

[0057] While the present disclosure has been described in conjunction with the exemplary embodiments outlined above, various alternatives, modifications, variations, improvements, and / or substantial equivalents, whether known or foreseeable now or in the near future, may become apparent to those skilled in the art. Accordingly, the exemplary embodiments of the present disclosure described above are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit or scope of the present disclosure. Accordingly, the present disclosure is intended to embrace all known or earlier-developed alternatives, modifications, variations, improvements, and / or substantial equivalents. The technical advantages and technical problems described herein are illustrative and not limiting. It should be noted that the embodiments described herein may have other technical advantages and solve other technical problems.

Claims

1. A compressor control system for a refrigeration system, the refrigeration system (110) comprising a compressor (100) and an economizer (103), the compressor (100) comprising a slide valve (232), the economizer (103) being provided with an inlet pipe (113), a gas outlet pipe (114), and a liquid outlet pipe (115), the compressor control system comprising: inlet pipe sensors (121, 122) for detecting pressure and temperature parameters of the inlet pipe (113); gas outlet pipe sensors (123, 124) for detecting pressure and temperature parameters of the gas outlet pipe (114); liquid outlet line sensors (125, 126) for detecting pressure and temperature parameters of the liquid outlet line (115); A control device (120) comprising: receiving pressure and temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115); configured to control the movement of the slide valve (232) based on the pressure parameter and the temperature parameter to adjust the position of the slide valve (232); A control device (120) A compressor control system comprising:

2. the inlet pipe sensors (121, 122) include an inlet pipe pressure sensor (122) and an inlet pipe temperature sensor (121), the inlet pipe pressure sensor (122) and the inlet pipe temperature sensor (121) being configured to detect the pressure parameter and the temperature parameter of the inlet pipe (113), respectively; the gas outlet pipe sensors (123, 124) comprise a gas outlet pipe pressure sensor (124) and a gas outlet pipe temperature sensor (123), the gas outlet pipe pressure sensor (124) and the gas outlet pipe temperature sensor (123) being configured to detect the pressure parameter and the temperature parameter of the gas outlet pipe (114), respectively; 2. The compressor control system for a refrigeration system according to claim 1, wherein the liquid outlet piping sensors (125, 126) comprise a liquid outlet piping pressure sensor (126) and a liquid outlet piping temperature sensor (125), the liquid outlet piping pressure sensor (126) and the liquid outlet piping temperature sensor (125) being configured to detect the pressure parameter and the temperature parameter of the liquid outlet piping, respectively.

3. The refrigeration system (110) has an external volume ratio Vi sys the compressor (100) has an internal volume ratio Vi, and the slide valve (232) is used to adjust the internal volume ratio Vi of the compressor (100); The control device (120) receiving the respective pressure parameters and the respective temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115); calculating a calibration factor A for the compressor (100) based on the individual pressure parameters and the individual temperature parameters; The external volume ratio Vi sys and calculating the internal volume ratio Vi of the compressor (100) according to the calibration coefficient A; The compressor control system in a refrigeration system of claim 2 , configured to adjust the position of the slide valve (232) according to the internal volume ratio Vi.

4. The compressor (100) further comprises a drive unit (233), the drive unit (233) being communicatively connected to the control unit (120); the slide valve (232) has a first position corresponding to a minimum internal volume ratio of the compressor (100) and a second position corresponding to a maximum internal volume ratio of the compressor (100); 4. The compressor control system in a refrigeration system according to claim 3, wherein the drive device (233) is configured to drive the slide valve (232) to move between the first position and the second position to adjust the internal volume ratio of the compressor (100).

5. The compressor (100) is provided with a suction pipe (111) and an exhaust pipe (112), The compressor control system further comprises: an inlet pressure sensor (127) configured to detect a pressure parameter of the inlet pipe (111); an exhaust pressure sensor (128) configured to detect a pressure parameter of the exhaust pipe (112); Equipped with The control device (120) determines the external volume ratio Vi based on the pressure parameter of the intake pipe (111) and the pressure parameter of the exhaust pipe (112). sys The compressor control system in a refrigeration system of claim 3 configured to calculate:

6. The calculation of the calibration factor A for the compressor (100) based on the individual pressure parameters and the individual temperature parameters comprises: The enthalpy value H of the inlet refrigerant in the inlet pipe (113) according to the pressure parameter and the temperature parameter of the inlet pipe (113) 1 and The enthalpy value H of the liquid refrigerant in the liquid outlet pipe (115) according to the pressure parameter and the temperature parameter of the liquid outlet pipe (115) 2 and The enthalpy value H of the gas refrigerant in the gas outlet pipe (114) according to the pressure parameter and the temperature parameter of the gas outlet pipe (114) 3 and The following formula: A=(H 1 -H 2 ) / (H 3 -H 1 ) to obtain the calibration coefficient A according to The compressor control system of claim 5, comprising:

7. The control device (120) is configured to calculate the following equation: Vi = Vi sys 7. The compressor control system in a refrigeration system according to claim 6, configured to calculate the internal volume ratio Vi according to / (1+A).

8. A control method for a compressor control system in a refrigeration system, the refrigeration system (110) comprising a compressor (100) and an economizer (103), the compressor (100) comprising a slide valve (232), the economizer (103) being provided with an inlet pipe (113), a gas outlet pipe (114), and a liquid outlet pipe (115), the control method comprising: receiving pressure and temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115); controlling the movement of the slide valve (232) based on the individual pressure parameters and the individual temperatures to adjust the position of the slide valve (232); A control method comprising:

9. The refrigeration system (110) has an external volume ratio Vi sys wherein the compressor (100) has an internal volume ratio Vi, and the slide valve (232) is used to control the internal volume ratio Vi of the compressor (100); Controlling the movement of the slide valve (232) based on the individual pressure parameters and the individual temperatures comprises: calculating a calibration factor A for the compressor (100) based on the individual pressure parameters and the individual temperature parameters; The external volume ratio Vi sys and calculating the internal volume ratio Vi of the compressor (100) according to the calibration coefficient A; adjusting the position of the slide valve (232) according to the internal volume ratio Vi; The method of claim 8, comprising:

10. The compressor (100) is provided with an intake pipe (111) and an exhaust pipe (112), and the external volume ratio Vi sys The control method for a compressor control system according to claim 9, wherein the pressure parameter of the intake pipe (111) and the pressure parameter of the exhaust pipe (112) are calculated based on the pressure parameter of the intake pipe (111).

11. The enthalpy value H of the refrigerant drawn into the inlet pipe (113) 1 is calculated based on the pressure parameter and the temperature parameter of the inlet pipe (113), The enthalpy value H of the liquid refrigerant in the liquid outlet pipe (115) 2 is calculated according to the pressure parameter and the temperature parameter of the liquid outlet pipe (115), The enthalpy value H of the gas refrigerant in the gas outlet pipe (114) 3 is calculated according to the pressure parameter and the temperature parameter of the gas outlet pipe (114), The calibration coefficient A is calculated by the following formula: A=(H 1 -H 2 ) / (H 3 -H 1 10. The control method for a compressor control system according to claim 9, wherein the calculated value is calculated according to the following formula:

12. The internal volume ratio Vi is expressed by the following formula: Vi = Vi sys 10. The control method for a compressor control system according to claim 9, wherein the calculated value is calculated according to / (1+A).

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