WO2024041391A1 - Compressor control system and control method thereof - Google Patents

Abstract

The present application discloses a compressor control system in a refrigeration system and a control method. The refrigeration system comprises a compressor and an economizer, wherein the compressor comprises a sliding valve, and the economizer is provided with an inlet pipeline, a gas outlet pipeline and a liquid outlet pipeline. The compressor control system comprises: inlet pipeline sensors; gas outlet pipeline sensors; liquid outlet pipeline sensors; and a control device configured to: receive pressure parameters and temperature parameters of the inlet pipeline, the gas outlet pipeline and the liquid outlet pipeline; and control movement of the sliding valve on the basis of the pressure parameters and the temperature parameters, so as to adjust the position of the sliding valve. In the present application, the change in the actual internal volume ratio of the compressor is reflected by means of the change in the mass and density of a refrigerant discharged from an exhaust port of the compressor. The influence of economizer pipeline design and pressure drop is avoided, so that the calibration result of the internal volume ratio of the compressor is more accurate and reliable.

Description

Compressor control system and control method thereof Technical field

The present application relates to the field of refrigeration systems, and in particular to a compressor control system and a control method thereof in a refrigeration system.

Background technique

Screw compressors are common components in refrigeration systems. The screw compressor uses the tooth space volumes of a pair of screw rotors to mesh with each other, causing changes in the volume of the primitive composed of tooth-shaped spaces to complete the process of gas suction, compression and discharge. The internal volume ratio Vi (Vi=Vs/Vd) is an important operating parameter of the screw compressor, where Vs represents the rotor suction chamber volume and Vd represents the rotor exhaust chamber volume. By adjusting the position of the slide valve, the volume of the rotor exhaust chamber can be adjusted, thereby adjusting the internal volume ratio Vi.

According to the different working conditions of the refrigeration system, the system has different external volume ratio Vi _sys . Desirably, the internal volume ratio Vi of the compressor can match the external volume ratio Vi _sys of the refrigeration system, so that the rotor discharge chamber pressure of the compressor is equal to the discharge pressure of the refrigeration system, thereby avoiding over- or under-compression. The extra power consumption ensures that the compressor operates at optimal efficiency.

Contents of the invention

At least one object of the present application in a first aspect is to provide a compressor control system in a refrigeration system, the refrigeration system including a compressor and an economizer, wherein the compressor includes a slide valve and the economizer has an inlet pipe , gas outlet pipeline and liquid outlet pipeline, the compressor control system includes: an inlet pipeline sensor for detecting the pressure and temperature parameters of the inlet pipeline; a gas outlet pipeline sensor for detecting the pressure of the gas outlet pipeline and temperature parameters; a liquid outlet pipe sensor for detecting the pressure and temperature parameters of the liquid outlet pipe; and a control device configured to: receive the inlet pipe, the gas outlet pipe and the liquid Pressure parameters and temperature parameters of the outlet pipe; control the movement of the slide valve based on the pressure parameters and temperature parameters, thereby adjusting the position of the slide valve.

According to the above first aspect, the inlet pipe sensor includes an inlet pipe pressure sensor and an inlet pipe temperature sensor. The sensor, the inlet pipeline pressure sensor and the inlet pipeline temperature sensor are configured to detect the pressure parameters and temperature parameters of the inlet pipeline respectively; the gas outlet pipeline sensor includes a gas outlet pipeline pressure sensor and a gas outlet pipeline temperature sensor, so The gas outlet pipeline pressure sensor and the gas outlet pipeline temperature sensor are configured to detect the pressure parameters and temperature parameters of the gas outlet pipeline respectively; the liquid outlet pipeline sensor includes a liquid outlet pipeline pressure sensor and a liquid outlet pipeline temperature sensor, the The liquid outlet pipe pressure sensor and the liquid outlet pipe temperature sensor are configured to detect pressure parameters and temperature parameters of the liquid outlet pipe, respectively.

According to the above 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, and the control device is configured To: receive each pressure parameter and each temperature parameter of the inlet pipe, the gas outlet pipe and the liquid outlet pipe; calculate the calibration coefficient A of the compressor based on each pressure parameter and each temperature parameter; according to the external volume ratio Vi _sys and calibration coefficient A calculate the internal volume ratio Vi of the compressor; adjust the position of the slide valve according to the internal volume ratio Vi.

According to the above first aspect, the compressor further includes a driving device, the driving device is communicatively connected with the control device; the slide valve has a first position corresponding to the minimum internal volume ratio of the compressor and a first position corresponding to the minimum internal volume ratio of the compressor. a second position of the maximum internal volume ratio of the compressor; wherein the driving device is configured to drive the slide valve to move between the first position and the second position to adjust the Content volume ratio.

According to the above first aspect, the compressor has a suction pipe and a discharge pipe; the compressor control system further includes: a suction pressure sensor configured to detect the pressure of the suction pipe parameter; an exhaust pressure sensor configured to detect a pressure parameter of the exhaust pipe; wherein the control device is configured to detect a pressure parameter of the exhaust pipe based on the pressure parameter of the suction pipe and the exhaust pipe The pressure parameter is calculated to obtain the external volume ratio Vi _sys .

According to the above first aspect, the calculation of the calibration coefficient A of the compressor based on each pressure parameter and each temperature parameter includes: calculating the inlet refrigerant in the inlet pipeline based on the pressure parameters and temperature parameters of the inlet pipeline. The enthalpy value H ₁ ; the enthalpy value H 2 of the liquid refrigerant in the liquid outlet pipe is calculated based on the pressure parameters and temperature parameters of the liquid outlet pipe; the enthalpy value H ₂ is calculated based on the pressure parameters and temperature parameters of the gas outlet pipe The enthalpy value H ₃ of the gas refrigerant in the gas outlet pipe is determined; the calibration coefficient A is obtained according to the following formula: A=(H ₁ -H ₂ )/(H ₃ -H ₁ ).

According to the above first aspect, the control device is configured to calculate the internal volume ratio Vi according to the following formula: Vi=Vi _sys /(1+A).

At least one object of the second aspect of the present application is to provide a control method for a compressor control system in a refrigeration system. The refrigeration system includes a compressor and an economizer, wherein the compressor includes a slide valve, and the economizer There is an inlet pipeline, a gas outlet pipeline and a liquid outlet pipeline, and the control method includes the following steps: receiving pressure parameters and temperature parameters of the inlet pipeline, the gas outlet pipeline and the liquid outlet pipeline; based on each pressure parameter and each The temperature controls the movement of the slide valve, thereby adjusting the position of the slide valve.

According to the above second aspect, the refrigeration system has an external volume ratio Vi _sys , 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 each temperature to control the movement of the slide valve including: calculating the calibration coefficient A of the compressor based on each pressure parameter and each temperature parameter; calculating the internal volume ratio of the compressor based on the external volume ratio Vi _sys and the calibration coefficient A Vi; adjust the position of the slide valve according to the internal volume ratio Vi.

According to the above second aspect, the compressor has a suction pipe and an exhaust pipe, wherein the external volume ratio Vi _sys is calculated based on a pressure parameter of the suction pipe and a pressure parameter of the exhaust pipe.

According to the above second aspect, the inlet refrigerant enthalpy value H ₁ in the inlet pipe is calculated according to the pressure parameters and temperature parameters of the inlet pipe; the liquid is calculated according to the pressure parameters and temperature parameters of the liquid outlet pipe. The enthalpy value H ₂ of the liquid refrigerant in the outlet pipe; the enthalpy value H ₃ of the gas refrigerant in the gas outlet pipe is calculated according to the pressure parameters and temperature parameters of the gas outlet pipe; the calibration coefficient A is calculated according to the following formula: A=(H ₁ -H ₂ )/(H ₃ -H ₁ ).

According to the above second aspect, the internal volume ratio Vi is calculated according to the following formula: Vi=Vi _sys /(1+A).

Other features, advantages, and embodiments of the present application may be set forth or become apparent by consideration of the following detailed description, drawings, and claims. Furthermore, it is to be understood that both the foregoing summary and the following detailed description are exemplary and are intended to provide further explanation without limiting the scope of the application as claimed. However, the detailed description and specific examples are merely indicative of preferred embodiments of the present application. To those skilled in the art, various changes and modifications within the spirit and scope of the present application will become apparent from this detailed description. And easy to see.

Description of drawings

Figure 1 is a schematic structural diagram of a refrigeration system according to an embodiment of the present application;

Figure 2A is a schematic structural diagram of the compressor when the slide valve is in the first position;

Figure 2B is a schematic structural diagram of the compressor when the slide valve is in the second position;

Figures 3A-3C are structural block diagrams of the control device;

4A-4C are flow charts of the control method.

Detailed ways

Various embodiments of the present application will be described below with reference to the accompanying drawings, which constitute a part of this specification. It should be understood that although terms indicating directions are used in this application, such as "front", "back", "upper", "lower", "left", "right", "top", "bottom", etc. Various example structural parts and elements are used herein, but these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Since the embodiments disclosed in the present application can be arranged in different directions, these terms indicating directions are for illustration only and should not be regarded as limiting.

Figure 1 shows a schematic structural 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 that are fluidly connected in sequence.

The high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 107 of the compressor 100 enters the condenser 101 , releases heat to condense 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 part of the liquid refrigerant evaporates into a gaseous refrigerant and returns to the compressor 100. The other part of the liquid refrigerant is cooled into a subcooled liquid refrigerant and enters the throttling device 104, where it is throttled into low-pressure two-phase refrigeration. The refrigerant then enters the evaporator 102, absorbs heat in the evaporator 102 to evaporate into gaseous refrigerant, and finally returns to the compressor 100 through the suction port 106 of the compressor 100, completing the circulation flow of the refrigerant.

Refrigeration system 110 also includes a compressor control system including control device 120 . The compressor control system is used to control the internal volume ratio of the compressor so that the compressor rotor discharge chamber pressure (i.e. internal pressure) is consistent with the discharge pressure of the refrigeration system (i.e. external pressure), thereby avoiding over-compression or under-compression. Adjusting the internal volume ratio of the compressor in real time according to the operating conditions of the refrigeration system 110 can improve the operating efficiency of the refrigeration system and reduce energy consumption.

In the refrigeration system 110 including the economizer 103 of the present application, the change in the density of the refrigerant gas in the discharge chamber of the compressor 100 is used to reflect the change in the internal volume ratio Vi of the compressor, and the heat exchange energy of the economizer is used The principle of conservation obtains the calibration coefficient A, so that the internal volume ratio Vi can be calibrated to the equivalent internal volume ratio Vi*. Then the control device 120 sets the equivalent internal volume ratio Vi* equal to the external volume ratio Vi _sys of the refrigeration system, and then inverses the actual internal volume ratio of the compressor 100 based on the external volume ratio Vi _sys of the refrigeration system 110 and the calibration coefficient A. Vi, finally adjusting the position of the slide valve 232 of the compressor (see Figures 2A and 2B) according to the actual internal volume ratio Vi, can make the rotor discharge chamber pressure of the compressor 100 equal to the discharge pressure of the refrigeration system 110 Consistent to avoid over- or under-compression.

Specifically, the compressor control system includes a suction pressure sensor 127 and a discharge pressure sensor 128 . The suction pressure sensor 127 is provided on 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 between the discharge port 107 of the compressor 100 and the condenser 101 on the exhaust pipe 112. The suction pressure sensor 127 and the exhaust pressure sensor 128 are communicatively connected with the control device 120, and are respectively used to detect the suction pressure Ps in the suction pipe 111 and the exhaust pressure Pd in the exhaust pipe 112, and obtain respective pressure parameters. . The external volume ratio Vi _sys of the refrigeration system can be calculated through the suction pressure Ps and the discharge pressure Pd.

The economizer 103 is in fluid communication with the condenser 101 through the inlet pipe 113 , with the gas supply port 108 of the compressor 100 through the gas outlet pipe 114 , and with the throttling device 104 through the liquid outlet pipe 115 . The compressor control system also includes inlet pipe sensors, gas outlet pipe sensors, and liquid outlet pipe sensors. These sensors are also communicatively connected with the control device 120 . The inlet pipe sensor is arranged on the inlet pipe 113 for detecting the pressure and temperature in the inlet pipe 113 and obtaining respective pressure parameters and temperature parameters. exist In this embodiment, the inlet pipe sensor includes an inlet pipe pressure sensor 122 and an inlet pipe temperature sensor 121 . The gas outlet pipe sensor is arranged on the gas outlet pipe 114 for detecting the pressure and temperature in the gas outlet pipe 114 and obtaining respective pressure parameters and temperature parameters. In this embodiment, the gas outlet pipe sensor includes a gas outlet pipe pressure sensor 124 and a gas outlet pipe temperature sensor 123 . The liquid outlet pipe sensor is arranged on the liquid outlet pipe 115 for detecting the pressure and temperature in the liquid outlet pipe 115 and obtaining 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 .

By detecting the pressure and temperature in each pipe of the economizer 103, the enthalpy value H ₁ of the inlet refrigerant entering the economizer 103 from the inlet pipe 113 and the enthalpy value of the liquid refrigerant flowing out of the economizer 103 from the liquid outlet pipe 115 can be obtained. H ₂ , and the enthalpy H ₃ of the gas refrigerant flowing out of the economizer 103 from the gas outlet pipe 114 . The calibration coefficient A can be calculated based on the enthalpy value H ₁ of the inlet refrigerant, the enthalpy value H ₂ of the liquid refrigerant, and the enthalpy value H ₃ of the gas refrigerant. The calibration coefficient A reflects the change in the density of the compressor's discharge cavity caused by the economizer air supply.

According to the external volume ratio Vi _sys of the refrigeration system and the calibration coefficient A of the compressor, the internal volume ratio Vi of the compressor is calculated back to Vi = Vi _sys × (1 + A). The specific calculation method will be described in detail with reference to Figure 2A and Figure 2B.

2A and 2B show a schematic structural diagram of the compressor, wherein FIG. 2A shows the state when the slide valve is in the first position, and FIG. 2B shows the state when the slide valve is in the 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 in fluid communication with the suction pipe 111 through the suction port 106 . The discharge chamber 237 is in fluid communication with the suction pipe 111 through the suction port 106 . The gas port 107 is in fluid communication with the exhaust conduit 112 . The compression chamber 231 is formed by the tooth grooves of a pair of screw rotors, and the compression chamber 231 is fluidly connected to the suction chamber 236 and the exhaust chamber 237 . The air supply port 108 is in fluid communication with 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 for compression. Moreover, the refrigerant in the gas outlet pipe 114 can also flow into the compression chamber 231 through the air supply port 108 for compression. After the two parts of refrigerant are compressed, they enter the exhaust chamber 237 together, and are finally discharged into the exhaust pipe 112 through the exhaust port 107 to complete the compression process of the compressor 100 .

The compressor 100 also includes a slide valve 232 and a driving device 233. The driving device 233 is mechanically connected to the slide valve 232. To drive the slide valve 232 to move. And the driving device 233 is communicatively connected with 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 moves to the leftmost position (ie, the first position) as shown in FIG. 2A , the exhaust chamber 237 has the largest exhaust chamber volume and therefore has the smallest internal volume ratio. When the slide valve 232 moves to the rightmost position (ie, the second position) as shown in FIG. 2B , the exhaust chamber 237 has the smallest exhaust chamber volume, and therefore has the largest internal volume ratio. The driving device 233 is used to control the slide valve 232 to move between the first position and the second position to adjust the volume of the exhaust chamber 237 and thereby adjust the internal volume ratio Vi of the compressor 100 . Those skilled in the art can understand that the driving device 233 may include a position sensor (not shown in the figure) for detecting the position of the slide valve to control the movement position of the slide valve 232 .

Compared with a refrigeration system that does not include an economizer, even if the system operating conditions and the position of the slide valve 232 remain unchanged, the actual internal volume ratio of the compressor 100 will change due to the refrigerant entering the compression chamber 231 from the air supply port 108 . Therefore, if the position of the slide valve 232 is directly adjusted according to the external volume ratio Vi _sys of the refrigeration system 110 , the actual internal volume ratio Vi of the compressor 100 will be inconsistent with the external volume ratio Vi _sys of the refrigeration system 110 .

In the compressor control system of this application, the calibrated equivalent internal volume ratio Vi* is set equal to the external volume ratio Vi _sys , and then the internal volume ratio Vi of the compressor is obtained by inverse calculation based on the calibration coefficient A of the compressor. 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 consistent with the external volume ratio Vi _sys of the refrigeration system 110 .

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

The equivalent internal volume ratio Vi* of the compressor 100 is equal to ρd*/ρs, where ρd* represents the exhaust density of the compressor, and ρs represents the suction density of the compressor.

And ρs=m ₂ /Vs, ρd*=(m ₂ +m ₃ )/Vd. Here m ₂ represents the mass of the liquid refrigerant flowing out from the liquid outlet pipe 115, that is, the suction volume of the compressor, and m ₃ represents the mass of the gas refrigerant flowing out from the economizer gas outlet pipe 114, that is, the air supply volume of the economizer. Vs represents the suction chamber volume, and Vd represents the exhaust chamber volume. Thus, the calibration formula of the internal volume ratio Vi of the compressor is obtained, which is the equivalent internal volume ratio Vi* and internal volume ratio Vi of the compressor. The relationship is: Vi*=[(m ₂ +m ₃ )/m ₂ ]×Vi.

The control device 120 sets the equivalent internal volume ratio Vi* of the compressor 100 to be consistent with the system external volume ratio Vi _sys . That is, Vi _sys =Vi*=[(m ₂ +m ₃ )/m ₂ ]×Vi. Therefore, it can be deduced that Vi=Vi _sys ×[m ₂ /(m ₂ +m ₃ )].

Furthermore, since the refrigerant entering the economizer 103 from the inlet pipe 113 undergoes heat exchange inside the economizer 103, according to the thermal energy conservation of the economizer, the refrigerant satisfies m ₃ × (H ₃ -H ₁ ) = m ₂ × ( H ₁ –H ₂ ). Here m ₁ represents the total mass of inlet refrigerant entering the economizer 103 from the inlet pipe 113 .

Therefore, Vi _sys =[(m ₂ +m ₃ )/m ₂ ]×Vi=(1+m ₃ /m ₂ )×Vi=(1+A)×Vi. Calibration coefficient A of the compressor=(H ₁ -H ₂ )/(H ₃ -H ₁ ).

Therefore, the internal volume ratio of the compressor Vi=Vi _sys /(1+A) can be calculated based on the external volume ratio Vi _sys of the refrigeration system and the calibration coefficient A of the compressor.

3A-3C show a structural block diagram 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 with a control program 346. Each component in the control device 120, including the processor 342, input interface 343, output interface 344 and memory 345, is communicatively connected to the bus 341, so that 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 used to store programs, instructions and data, and the processor 342 reads the programs, instructions and data from the memory 345 and can 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.

As shown in Figures 3A-3C, the input interface 343 is 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 through the connection 347. The outlet pipe pressure sensor 126 , as well as the suction pressure sensor 127 and the exhaust pressure sensor 128 are communicatively connected to receive pressure and/or temperature parameters from each sensor and store these pressure and/or temperature parameters into the memory 345 . The output interface 344 is communicatively connected to the drive device 233 of the compressor 100 via a connection 348 . By executing the program 346 in the memory 345, the control device 120 controls the position of the slide valve 232 by controlling the drive device 233.

4A-4C are flow charts of the control method of the compressor control system.

At step 450, the process begins.

At step 451, the control device 120 performs step 452 to obtain the external volume ratio Vi _sys of the refrigeration system, and performs step 453 to obtain the calibration coefficient A of the compressor.

At step 454, the control device 120 calculates the internal volume ratio Vi of the compressor based on the obtained external volume ratio Vi _sys and the calibration coefficient A.

At step 455, the control device 120 controls the movement of the driving device 233 according to the internal volume ratio Vi to adjust the position of the slide valve 232.

At step 456, the control device 120 determines whether the refrigeration system 110 ends operation. When the refrigeration system 110 ends operation, step 457 is performed. When the refrigeration system 110 has not finished running, return to step 451.

At step 457, the process ends.

Among them, step 452 includes step 461 and step 462. In step 461 , the control device 120 receives pressure parameters from the suction pressure sensor 127 and the exhaust pressure sensor 128 .

In step 462, the control device 120 obtains the external volume ratio Vi _sys through calculation.

Step 453 includes step 464, step 465 and step 466. At step 464, the control device 120 receives the pressures of 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 parameters and temperature parameters.

In step 465, the control device 120 calculates the enthalpy H ₁ of the refrigerant in the inlet pipe 113 , the enthalpy H ₂ of the refrigerant in the liquid outlet pipe 115 , and the enthalpy of the refrigerant in the gas outlet pipe 114 _H3 .

In step 466, the control device 120 obtains the calibration coefficient A through calculation.

When the refrigeration system does not include an economizer, by making the internal volume ratio of the compressor consistent with the external volume ratio of the refrigeration system, the rotor discharge chamber pressure of the compressor can be made consistent with the discharge pressure of the refrigeration system. But when the refrigeration system When an economizer is included in the system, the refrigerant discharged from the exhaust port 107 includes the refrigerant sucked from the suction port 106 as well as the refrigerant sucked from the air supply port 108 . Therefore, compared with a refrigeration system that does not include an economizer, when the slide valve of the compressor is in the same position, under the same system operating conditions and suction pressure, the volume of refrigerant discharged from the exhaust port 107 is different. As the mass and density increase, the compressor's rotor exhaust chamber pressure is greater than the exhaust pressure of the refrigeration system, resulting in undesirable over-compression of the refrigeration system.

If the method of replacing the gas outlet pressure of the economizer with the suction pressure Ps of the refrigeration system is used to calibrate the external volume ratio Vi _sys of the refrigeration system, then set the slider position of the compressor to make the internal volume ratio Vi of the compressor equal to The calibrated external volume ratio Vi _sys is consistent. This calibration method, which uses pressure substitution to reflect the influence of the economizer, is greatly affected by pipeline design and pipeline pressure drop, making the calibration results inaccurate.

In this application, the internal volume ratio Vi of the compressor is calibrated to the external volume ratio Vi _sys of the system through changes in the mass and density of the refrigerant discharged from the exhaust port of the compressor and the operating conditions of the economizer. With the same equivalent internal volume ratio Vi*, the calibration results are more accurate and reliable. The calibration method of this application is only related to the enthalpy value at each connecting pipe of the economizer, and has nothing to do with the pipeline design and pipeline pressure drop, thus avoiding the influence of pressure drop. According to the calibration results, the compressor control system of the present application can adjust the internal volume ratio Vi of the compressor in real time according to the external volume ratio Vi _sys of the system during the operation of the refrigeration system, thereby improving the working efficiency of the refrigeration system and reducing the cost of the refrigeration system. energy consumption.

Moreover, in this application, when calculating the calibration coefficient A, there is no need to directly detect the mass or pressure. Instead, the calibration coefficient A is obtained by converting the mass ratio into an enthalpy value. The calculation method is simpler and more accurate.

In addition, since the compressor control system of the present application only needs to calculate the enthalpy values at the inlet and each outlet of the economizer, it is also suitable for controlling a compressor with multiple air supply ports.

Although the present disclosure has been described in connection with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or not, will become apparent to those of at least ordinary skill in the art. It may be obvious whether it is now or can be foreseen in the near future. Accordingly, the examples of embodiments of the present disclosure set forth above are intended to be illustrative and not restrictive. Various changes may be made without departing from the spirit or scope of the disclosure. Accordingly, this disclosure is intended to include all known or earlier developed alternatives, Modifications, variations, improvements and/or substantial equivalents. The technical effects and technical problems in this specification are illustrative rather than restrictive. It should be noted that the embodiments described in this specification may have other technical effects and may solve other technical problems.

Claims (12)

1. A compressor control system in a refrigeration system. The refrigeration system (110) includes a compressor (100) and an economizer (103). The compressor (100) includes a slide valve (232). The economizer (103) has an inlet pipe (113), a gas outlet pipe (114) and a liquid outlet pipe (115), characterized in that the compressor control system includes:

   Inlet pipe sensors (121, 122), used to detect the pressure and temperature parameters of the inlet pipe (113);

   Gas outlet pipe sensors (123, 124), used to detect the pressure and temperature parameters of the gas outlet pipe (114);

   Liquid outlet pipe sensors (125, 126) for detecting pressure and temperature parameters of the liquid outlet pipe (115); and

   Control device (120), the control device (120) is configured to:

   Receive pressure parameters and temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115);

   The movement of the slide valve (232) is controlled based on the pressure parameter and the temperature parameter, thereby adjusting the position of the slide valve (232).
2. The compressor control system in the refrigeration system according to claim 1, characterized in that:

   The inlet pipe sensor (121, 122) includes 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) are configured to respectively detect the inlet Pressure parameters and temperature parameters of pipeline (113);

   The gas outlet pipe sensor (123, 124) includes a gas outlet pipe pressure sensor (124) and a gas outlet pipe temperature sensor (123), and the gas outlet pipe pressure sensor (124) and the gas outlet pipe temperature sensor (123) are configured as Detect the pressure parameters and temperature parameters of the gas outlet pipe (114) respectively;

   The liquid outlet pipe sensor (125, 126) includes a liquid outlet pipe pressure sensor (126) and a liquid outlet pipe temperature sensor (125), which are configured to respectively detect The pressure parameters and temperature parameters of the liquid outlet pipe (115).
3. The compressor control system in the refrigeration system according to claim 2, 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) Used to adjust the internal volume ratio Vi of the compressor (100), it is characterized by:

   The control device (120) is configured to:

   Receive various pressure parameters and various temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115);

   Calculate the calibration coefficient A of the compressor (100) based on each pressure parameter and each temperature parameter;

   Calculate the internal volume ratio Vi of the compressor (100) according to the external volume ratio Vi _sys and the calibration coefficient A;

   The position of the slide valve (232) is adjusted according to the internal volume ratio Vi.
4. The compressor control system in the refrigeration system according to claim 3, characterized in that:

   The compressor (100) also includes a driving device (233), and the driving device (233) is communicatively connected with the control device (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);

   The driving 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 control system in the refrigeration system according to claim 3, characterized in that:

   The compressor (100) has a suction pipe (111) and an exhaust pipe (112);

   The compressor control system also includes:

   a suction pressure sensor (127), the suction pressure sensor (127) being configured to detect the pressure parameter of the suction pipe (111);

   an exhaust pressure sensor (128) configured to detect a pressure parameter of the exhaust pipe (112);

   Wherein, the control device (120) is configured to calculate the external volume ratio Vi _sys based on the pressure parameter of the suction pipe (111) and the pressure parameter of the exhaust pipe (112).
6. The compressor control system in the refrigeration system according to claim 5, characterized in that:

   The calculation of the calibration coefficient A of the compressor (100) based on each pressure parameter and each temperature parameter includes:

   The enthalpy value H ₁ of the inlet refrigerant in the inlet pipe (113) is calculated according to the pressure parameters and temperature parameters of the inlet pipe (113);

   The enthalpy value H ₂ of the liquid refrigerant in the liquid outlet pipe (115) is calculated according to the pressure parameters and temperature parameters of the liquid outlet pipe (115);

   The enthalpy value H ₃ of the gas refrigerant in the gas outlet pipe (114) is calculated according to the pressure parameters and temperature parameters of the gas outlet pipe (114);

   Calibration coefficient A is obtained according to the following formula:
   A=(H ₁ -H ₂ )/(H ₃ -H ₁ ).
7. The compressor control system in the refrigeration system according to claim 6, characterized in that:

   The control device (120) is configured to calculate the internal volume ratio Vi according to the following formula:
   Vi= _Visys /(1+A).
8. A control method for a compressor control system in a refrigeration system. The refrigeration system (110) includes a compressor (100) and an economizer (103), wherein the compressor (100) includes a slide valve (232), so The economizer (103) has an inlet pipe (113), a gas outlet pipe (114) and a liquid outlet pipe (115), and is characterized in that the control method includes the following steps:

   Receive pressure parameters and temperature parameters of the inlet pipe (113), the gas outlet pipe (114) and the liquid outlet pipe (115);

   The movement of the slide valve (232) is controlled based on various pressure parameters and various temperatures, thereby adjusting the position of the slide valve (232).
9. The control method of the compressor control system according to claim 8, characterized in that:

   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 control the internal volume ratio Vi of the compressor (100);

   The controlling the movement of the slide valve (232) based on various pressure parameters and various temperatures includes:

   Calculate the calibration coefficient A of the compressor (100) based on each pressure parameter and each temperature parameter;

   Calculate the internal volume ratio Vi of the compressor (100) according to the external volume ratio Vi _sys and the calibration coefficient A;

   The position of the slide valve (232) is adjusted according to the internal volume ratio Vi.
10. The control method of the compressor control system according to claim 9, characterized in that:

    The compressor (100) has a suction pipe (111) and an exhaust pipe (112), wherein the pressure parameters of the suction pipe (111) and the pressure parameters of the exhaust pipe (112) are calculated. The above-mentioned external volume ratio Vi _sys .
11. The control method of the compressor control system according to claim 9, characterized in that:

    The inlet refrigerant enthalpy value H ₁ in the inlet pipe (113) is calculated according to the pressure parameters and temperature parameters of the inlet pipe (113);

    The enthalpy value H ₂ of the liquid refrigerant in the liquid outlet pipe (115) is calculated according to the pressure parameters and temperature parameters of the liquid outlet pipe (115);

    The gas refrigerant enthalpy value H ₃ in the gas outlet pipe (114) is calculated according to the pressure parameters and temperature parameters of the gas outlet pipe (114);

    The calibration coefficient A is calculated according to the following formula: A=(H ₁ -H ₂ )/(H ₃ -H ₁ ).
12. The control method of the compressor control system according to claim 9, characterized in that:

    The internal volume ratio Vi is calculated according to the following formula:
    Vi= _Visys /(1+A).