Method, device and equipment for compressor control and storage medium

Abstract

The invention relates to the technical field of compressors, and discloses a compressor control method, device and equipment and a storage medium. The compressor comprises a hot gas bypass valve, and the method comprises the steps that under the condition that it is determined that the current operation state of the compressor meets the compressor surge entering condition, the first current opening degree of an air inlet guide piece in the compressor and the second current opening degree of the hot gas bypass valve are obtained; maintaining or increasing the first current opening degree and the second current opening degree to correspondingly obtain a first adjustment opening degree and a second adjustment opening degree; and according to the first adjusting opening degree and the second adjusting opening degree, operation of an air inlet guide piece and a hot air bypass valve in the compressor is controlled correspondingly. In this way, the compression ratio of the compressor is reduced, and then the probability of the surge phenomenon of the compressor is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, for example, to methods, devices, equipment and storage media for compressor control. Background Art

[0002] Centrifugal compressors are widely used in industrial applications, such as air conditioning, refrigeration, heat pumps, and chemical industries. They need to operate stably under different load conditions to meet the temperature and pressure requirements of various uses. However, centrifugal compressors may experience surge during operation, that is, the airflow at the compressor inlet becomes unstable, resulting in problems such as reduced compressor performance, increased noise, and increased wear.

[0003] At present, centrifugal compressors can use variable frequency speed regulation technology to reduce the compressor speed in certain situations, reduce surge and increase equipment life. However, variable frequency speed regulation compressor technology automatically adjusts the operating speed of the compressor according to the difference between the actual temperature of the chilled water and the target temperature. Its response speed is not fast enough and not accurate enough.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] The embodiments of the present disclosure provide a method, device, apparatus and storage medium for compressor control to solve the technical problem of surge phenomenon during compressor operation. The compressor includes a hot gas bypass valve.

[0007] In some embodiments, the method comprises:

[0008] When it is determined that the current operating state of the compressor meets the compressor surge condition, obtaining a first current opening degree of an intake guide vane in the compressor and a second current opening degree of a hot gas bypass valve;

[0009] Maintain or increase the first current opening and the second current opening, and correspondingly obtain the first adjusted opening and the second adjusted opening;

[0010] According to the first adjustment opening and the second adjustment opening, the operation of the air intake guide vane and the hot gas bypass valve in the compressor are controlled respectively.

[0011] In some embodiments, the device for compressor control includes a processor and a memory storing program instructions, and the processor is configured to execute the above-mentioned method for compressor control when executing the program instructions.

[0012] In some embodiments, the storage medium stores program instructions, and when the program instructions are run, the above-mentioned method for compressor control is executed.

[0013] The method, device and apparatus for compressor control provided by the embodiments of the present disclosure can achieve the following technical effects:

[0014] The compressor includes a hot gas bypass valve, and when the operating state of the compressor meets the conditions for entering compressor surge, the opening of the compressor guide vane and the hot gas bypass valve can be maintained or increased to allow more high-pressure side gas to bypass to the low-pressure side, thereby increasing the pressure on the low-pressure side, thereby reducing the compression ratio of the compressor and further reducing the probability of compressor surge.

[0015] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0017] Figure 1 is a flow chart of a compressor control method provided by an embodiment of the present disclosure;

[0018] Figure 2 is a flow chart of a compressor control method provided by an embodiment of the present disclosure;

[0019] Figure 3 is a flow chart of a compressor control method provided by an embodiment of the present disclosure;

[0020] Figure 4 is a structural schematic diagram of a compressor control device provided by an embodiment of the present disclosure;

[0021] Figure 5 is a structural schematic diagram of a compressor control device provided by an embodiment of the present disclosure;

[0022] Figure 6 is a structural schematic diagram of a compressor control device provided by an embodiment of the present disclosure;

[0023] Figure 7It is a schematic diagram of a device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0025] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0026] Unless otherwise stated, the term "plurality" means two or more.

[0027] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0028] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0029] In the disclosed embodiment, the compressor uses a hot gas bypass valve to perform anti-surge control to ensure stable operation of the compressor under various working conditions. In addition, the opening range of the hot gas bypass valve is adjusted to optimize energy consumption and improve energy efficiency, thereby reducing the operating cost of the compressor under low load conditions.

[0030] The hot gas bypass valve is a mechanical device that uses the balance principle of refrigerant pressure and spring force to control the valve inlet / outlet pressure. It can bypass the high-pressure refrigerant to the low-pressure side of the system to keep the system working normally at a given minimum suction pressure. In the disclosed embodiment, the opening of the hot gas bypass valve is adjustable and controllable. In this way, the compression ratio of the compressor can be adjusted by adjusting the opening of the hot gas bypass valve to reduce the probability of compressor surge.

[0031] Figure 1 is a flow chart of a compressor control method provided by an embodiment of the present disclosure. The compressor includes a hot gas bypass valve, such as Figure 1As shown, the compressor control process includes:

[0032] Step 101: When it is determined that the current operating state of the compressor meets the compressor surge condition, a first current opening degree of an intake guide vane in the compressor and a second current opening degree of a hot gas bypass valve are obtained.

[0033] Surge is an unstable phenomenon in the compressor system, which may cause system performance degradation or even damage. Therefore, the compressor may be configured with a condition for entering compressor surge. When the operating state of the compressor meets the condition for entering compressor surge, it indicates that the compressor is about to experience surge. There are multiple ways to determine whether the current operating state of the compressor meets the condition for entering compressor surge. In some embodiments, determining whether the current operating state of the compressor meets the condition for entering compressor surge includes: monitoring the current of the compressor with a set sampling period, obtaining the current fluctuation rate corresponding to each sampling period, and determining the current fluctuation rate greater than the set current fluctuation rate as the first current fluctuation rate. When the current number of consecutive occurrences of the first current fluctuation rate is greater than the set number with the current moment as the end point, it is determined that the current operating state of the compressor meets the condition for entering compressor surge.

[0034] For example: the sampling period N1s can be set to monitor the current of the compressor, and in each set sampling period N1s, the current of the compressor can be collected every N2s, so that K sampled currents can be obtained in each set sampling period N1s, that is, in some embodiments, N1=N2*K. Among them, in each group of samples, the maximum value I1, the minimum value I2, and the average value I3 can be obtained respectively, so that the current fluctuation rate corresponding to each set sampling period N1s=(I1-I2) / I3. If the current fluctuation rate>the set current fluctuation rate appears n times continuously with the current moment as the end point, it is determined that the surge condition is met, and it can be determined that the current operating state of the compressor meets the compressor surge condition, and the corresponding anti-surge operation needs to be performed. 。

[0035] In some embodiments, the compression ratio of the compressor can be monitored to determine whether the operating state of the compressor meets the compressor surge conditions, that is, determining whether the current operating state of the compressor meets the conditions for entering compressor surge includes: obtaining the current compression ratio of the compressor, and when the current compression ratio is greater than the surge safety setting value, determining that the current operating state of the compressor meets the conditions for entering compressor surge.

[0036] Since surge is a phenomenon that may occur in compressors, in related technologies, a surge safety margin value is configured in the compressor. When the operating state of the compressor meets the conditions for entering compressor surge, it indicates that the compressor is about to experience surge. Therefore, the surge safety margin value can be reduced to obtain the corresponding surge safety setting value. For example: Surge safety setting value = surge safety margin value * surge safety margin value percentage. In this way, when the current compression ratio is greater than the surge safety margin value * surge safety margin value percentage, it can be determined that the current operating state of the compressor meets the conditions for entering compressor surge, and corresponding anti-surge operation is required. 。

[0037] In the disclosed embodiment, anti-surge operation is achieved by adjusting the corresponding openings of the air intake guide vane and the hot gas bypass valve in the compressor. Therefore, when it is determined that the current operating state of the compressor meets the conditions for entering compressor surge, it is necessary to obtain the opening of the air intake guide vane in the compressor and the opening of the hot gas bypass valve, which can correspond to the first current opening and the second current opening respectively at the current moment.

[0038] Step 102: Maintain or increase the first current opening and the second current opening, and correspondingly obtain a first adjusted opening and a second adjusted opening.

[0039] After maintaining or increasing the first current opening and the second current opening, in the compressor, the high-pressure side gas can pass through the hot gas bypass valve to the low-pressure side, so that the low-pressure pressure will increase, the compression ratio of the compressor will decrease, and the probability of surge occurrence will decrease accordingly.

[0040] In some embodiments, obtaining the first adjustment opening and the second adjustment opening includes: when the first current opening is less than or equal to the first set opening, determining the second set opening as the first adjustment opening, and, when the first current opening is greater than the first set opening, determining the first current opening as the first adjustment opening, wherein the second set opening is greater than the first set opening; when the second current opening is less than or equal to the third set opening, determining the third set opening as the second adjustment opening, and, when the second current opening is greater than the third set opening, determining the smaller value between the sum of the second current opening and the set increase value and the maximum set opening as the second adjustment opening.

[0041] The first set opening can be a%, the second set opening can be c%, the third set opening can be b%, and the set increase value can be d%. It can be determined according to the performance and application scenario of the compressor. For example, a% can be 30%, 35%, 40%, 45%, etc., c% can be 50%, 55%, 60%, etc., b% can be 45%, 50%, 55%, etc., and d% can be 10%, 20%, 25%, etc.

[0042] In some embodiments, if the first current opening Vd1≤35%, 52% can be determined as the first adjustment opening, that is, the first current opening is increased. If Vd1>35%, Vd1 is determined as the first adjustment opening, that is, the first current opening is maintained. If the second current opening Vd2≤48%, 48% can be determined as the second adjustment opening, that is, the second current opening is maintained, and if Vd2>48%, (Vd2+10%) can be compared with the maximum set opening, if (Vd2+10%)<maximum set opening, (Vd2+10%) can be determined as the second adjustment opening, and if (Vd2+10%)≥maximum set opening, the maximum set opening can be determined as the second adjustment opening, that is, the smaller value between the two is determined as the second adjustment opening, that is, the second current opening is increased.

[0043] Step 103: According to the first adjustment opening and the second adjustment opening, the operation of the intake guide vane and the hot gas bypass valve in the compressor are controlled respectively.

[0044] After the first adjustment opening and the second adjustment opening are determined, the operation of the intake guide vane and the hot gas bypass valve in the compressor can be controlled according to the first adjustment opening and the second adjustment opening. In this way, the high-pressure side gas in the compressor can pass through the hot gas bypass valve to the low-pressure side, thereby increasing the low-pressure pressure, reducing the compression ratio of the compressor, and reducing the probability of surge.

[0045] It can be seen that in the embodiment of the present disclosure, the compressor includes a hot gas bypass valve, and when the operating state of the compressor meets the conditions for entering compressor surge, the opening of the compressor guide vane and the hot gas bypass valve can be maintained or increased to allow more high-pressure side gas to bypass to the low-pressure side, thereby increasing the pressure on the low-pressure side, thereby reducing the compression ratio of the compressor and further reducing the probability of compressor surge.

[0046] Of course, when the current operating state of the compressor meets the conditions for exiting compressor surge, the compressor needs to exit anti-surge operation. In some embodiments, when it is determined that the current operating state of the compressor meets the conditions for exiting compressor surge, if it is determined that the compressor has no load reduction request, the second current opening of the hot gas bypass valve is reduced to obtain a third adjusted opening, and the operation of the hot gas bypass valve is controlled according to the third adjusted opening.

[0047] Among them, if the judgment of entering compressor surge condition is made by monitoring the current of the compressor, if the current number of times the first current fluctuation rate appears continuously for a set time, for example, 300s, with the current moment as the end point, is less than or equal to the set number n, it can be determined that the current operating state of the compressor meets the condition of exiting compressor surge. If the judgment of entering compressor surge condition is made by monitoring the compression ratio of the compressor, if the current compression ratio is less than or equal to the surge safety setting value, it can be determined that the current operating state of the compressor meets the condition of exiting compressor surge.

[0048] If the current operating state of the compressor satisfies the compressor surge exit condition and the compressor has no load reduction request, then the anti-surge operation needs to be exited. In some embodiments, exiting the anti-surge operation and obtaining the third adjustment opening includes: when the second current opening is less than the fourth set opening, determining the fifth set opening as the third adjustment opening, wherein the fifth set opening is less than the fourth set opening; when the second current opening is greater than or equal to the fourth set opening, determining the larger value between the difference between the second current opening and the set reduction value and the minimum set opening as the third adjustment opening.

[0049] The fourth setting opening degree may be e%, and the fifth setting opening degree may be f%, and the setting reduction value may be g%. The setting may be determined according to the performance and application scenario of the compressor. For example, e% may be 30%, 35%, 40%, etc., and f% may be 10%, 15%, 20%, etc., and g% may be 10%, 20%, 25%, etc.

[0050] In some embodiments, if the second current opening Vd2<30%, 20% may be determined as the third adjustment opening, and the operation of the hot gas bypass valve may be controlled according to the third adjustment opening. If the second current opening Vd2≥30%, the larger value between (Vd2-15%) and the minimum set opening may be determined as the third adjustment opening, and the operation of the hot gas bypass valve may be controlled according to the third adjustment opening.

[0051] In the disclosed embodiment, the compressor not only uses the hot gas bypass valve for anti-surge control, but also optimizes energy consumption and improves energy efficiency by adjusting the opening range of the hot gas bypass valve, that is, uses the hot gas bypass valve for energy regulation control. In addition, anti-surge control takes precedence over energy regulation control. Therefore, when it is determined that the current operating state of the compressor meets the conditions for exiting compressor surge, the compressor can also perform energy regulation control. Of course, the capacity regulation control of the compressor can be a default function, or, in some embodiments, the energy regulation control can correspond to a function button. After the user activates the function button, the compressor can use the hot gas bypass valve for energy regulation control.

[0052] In some embodiments, when it is determined that the current operating state of the compressor satisfies the conditions for entering a compressor low load, but does not satisfy the conditions for entering a compressor surge, that is, when it is determined that the current operating state of the compressor satisfies the conditions for exiting a compressor surge, and the current operating state of the compressor satisfies the conditions for entering a compressor low load, the chilled water temperature of the compressor is monitored; when the chilled water temperature is less than a first set temperature and the first duration corresponding to the temperature is greater than or equal to a first set time, the hot gas bypass valve is controlled to start and increase operation; when the chilled water temperature is greater than or equal to the first set temperature, and less than or equal to the second set temperature, the hot gas bypass valve is controlled to maintain unchanged operation.

[0053] In the disclosed embodiment, the compressor needs to perform energy regulation control when it is in a low-load operating state, and the opening of the air intake guide vane in the compressor can be used to determine whether the compressor is in a low-load operating state. Among them, a set entry opening can be determined based on the set minimum opening corresponding to the air intake guide, for example: set entry opening = set minimum opening + h%. In this way, the opening of the compressor air intake guide vane is monitored with a set sampling period. If the current moment is taken as the end point, the opening of the air intake guide vane sampled for N consecutive cycles is less than the set entry opening, it can be determined that the current operating state of the compressor meets the condition of entering the compressor low load. Of course, if the current moment is taken as the end point, the opening of the air intake guide vane sampled for N consecutive cycles is greater than or equal to the set entry opening, it can be determined that the current operating state of the compressor meets the condition of exiting the compressor low load.

[0054] When the current operating state of the compressor meets the conditions for exiting compressor surge and the conditions for entering compressor low load, energy regulation control can be performed, and the chilled water temperature of the compressor needs to be monitored.

[0055] The hot gas bypass valve is determined according to the design requirements of the unit unloading, the size of the compressor and other factors, and therefore, may correspond to an adjustable opening temperature T of the hot gas bypass valve. Therefore, the first set temperature may be determined according to the target temperature of the compressor, the shutdown temperature difference, and the adjustable opening temperature T of the hot gas bypass valve, that is, the first set temperature may be = target temperature - shutdown temperature difference + adjustable opening temperature T of the hot gas bypass valve. And the sum of the first set temperature + the set temperature i°C may be determined as the second set temperature.

[0056] The shutdown temperature may be between 1-3°C, for example, 2°C, and i°C may be 0.2°C, 0.5°C, 0.8°C, and so on.

[0057] In this way, when the monitored chilled water temperature is less than the first set temperature and the first duration T1 is greater than or equal to the first set time, that is, when the monitored chilled water temperature is less than the first set temperature and lasts for more than the first set time, the hot gas bypass valve can be controlled to start increasing operation. When the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature, the hot gas bypass valve can be controlled to maintain unchanged operation.

[0058] In some embodiments, controlling the hot gas bypass valve to start increasing operation includes: when the hot gas bypass valve is in a closed state, controlling the hot gas bypass valve to operate with a minimum set opening; when the hot gas bypass valve is in an operating state, determining the smaller value of the sum of the second current opening of the hot gas bypass valve and the set amplitude and the maximum set opening as a fourth adjustment opening, and controlling the operation of the hot gas bypass valve according to the fourth adjustment opening.

[0059] That is, when the hot gas bypass valve is closed, it is necessary to open the hot gas bypass valve and control the operation of the hot gas bypass valve with the minimum set opening. When the hot gas bypass valve is already opened, the set amplitude can be p%. The smaller value between (Vd2+p%) and the maximum set opening can be determined as the fourth adjustment opening, and the operation of the hot gas bypass valve is controlled according to the fourth adjustment opening.

[0060] Of course, in some embodiments, when it is determined that the current operating state of the compressor meets the conditions for exiting the compressor low load, if the chilled water temperature is greater than the second set temperature and the second duration corresponding to the temperature is greater than or equal to the second set time, the difference between the second current opening of the hot gas bypass valve and the set amplitude, and the larger value between 0, is determined as the fifth adjustment opening, and the operation of the hot gas bypass valve is controlled according to the fifth adjustment opening.

[0061] If the sampling opening of the air intake guide vane is greater than or equal to the set entry opening for N consecutive cycles, it can be determined that the current operating state of the compressor meets the conditions for exiting the compressor low load, and the monitored chilled water temperature is greater than the second set temperature and the second duration corresponding to the temperature is greater than or equal to the second set time. For example, the chilled water temperature is greater than the second set temperature for 5 seconds. At this time, the hot gas bypass valve needs to be closed, where the set amplitude can be q%. The larger value between (Vd2-q%) and 0 can be determined as the fifth adjustment opening, and the operation of the hot gas bypass valve is controlled according to the fifth adjustment opening.

[0062] It can be seen that in the embodiment of the present disclosure, the opening, holding and closing states of the hot gas bypass valve can be automatically adjusted according to parameters such as the chilled water temperature, the target temperature, and the shutdown temperature difference, so as to achieve energy regulation and reduce energy consumption. In addition, anti-surge control takes precedence over energy regulation control to ensure that when the anti-surge conditions are met, the hot gas bypass valve is controlled according to anti-surge first. This helps to protect the compressor from surge damage and extend the life of the equipment. In addition, the maximum opening, minimum opening, adjustment range and other parameters of the hot gas bypass valve can be flexibly set, that is, the control parameters can be customized according to needs, and fine adjustment can be achieved, which also improves the operating efficiency and stability of the compressor.

[0063] The operation flow is collected into a specific embodiment below to illustrate the compressor control process provided by the embodiment of the present invention.

[0064] In one embodiment of the present disclosure, the first setting opening a% may be 40%, the second setting opening c% may be 50%, the third setting opening b% may be 50%, the setting increase value d% may be 20%, the fourth setting opening e% may be 30%, the fifth setting opening f% may be 10%, and the setting decrease value g% may be 10%.

[0065] Figure 2 is a flow chart of a compressor control method provided by an embodiment of the present disclosure. Figure 2 As shown, the compressor control process includes:

[0066] Step 201: monitor the current of the compressor with a set sampling period, obtain the current fluctuation rate corresponding to each sampling period, determine the current fluctuation rate greater than the set current fluctuation rate as the first current fluctuation rate, and monitor the compression ratio of the compressor.

[0067] Step 202: Determine whether the current number of times the first current fluctuation rate appears continuously is greater than a set number n. If yes, execute step 204; otherwise, execute step 203.

[0068] Step 203: Determine whether the current compression ratio of the compressor is greater than the surge safety setting value. If yes, execute step 204; otherwise, execute step 211.

[0069] Among them, surge safety setting value = surge safety margin value * surge safety margin value percentage.

[0070] Steps 202 and 203 determine whether the current operating state of the compressor meets the compressor surge condition. The order of the two is not limited.

[0071] Step 204: The compressor obtains a first current opening degree of an intake guide vane in the compressor and a second current opening degree of a hot gas bypass valve.

[0072] Step 205: Determine whether the first current opening Vd1 ≤ 40% is established. If yes, execute step 206; otherwise, execute step 207.

[0073] Step 206 : The compressor determines 50% as the first adjustment opening, controls the operation of the air intake guide vane, and proceeds to step 208 .

[0074] Step 207 : The compressor determines the first current opening as the first adjusted opening, controls the operation of the air intake guide vane, and proceeds to step 208 .

[0075] Step 208: Determine whether the second current opening Vd2 ≤ 50% is established. If yes, execute step 209; otherwise, execute step 210.

[0076] Step 209 : the compressor determines 50% as the second adjustment opening, and controls the hot gas bypass valve to operate, and then proceeds to step 211 .

[0077] Step 210: The compressor determines the smaller value between (Vd2+20%) and the maximum set opening as the second adjustment opening, controls the operation of the hot gas bypass valve, and proceeds to step 211.

[0078] Step 211: Determine whether the duration of the first current fluctuation rate not occurring n times continuously is greater than 300 seconds. If yes, execute step 213; otherwise, execute step 212.

[0079] Step 212: Determine whether the duration of the compression ratio being less than or equal to the surge safety setting value is greater than 300 seconds. If yes, execute step 213; otherwise, execute step 201.

[0080] Step 213: Determine whether the compressor has a load reduction requirement. If yes, return to step 201; otherwise, execute step 214.

[0081] Step 214: The compressor obtains the second current opening degree Vd2 corresponding to the current moment.

[0082] Step 215: Determine whether the second current opening Vd2<30% is established. If so, execute step 216; otherwise, execute step 217.

[0083] Step 216: The compressor determines 10% as the third adjustment opening degree, and controls the hot gas bypass valve to operate.

[0084] Step 217: The compressor determines the larger value between (Vd2-10%) and the minimum set opening as the third adjustment opening, and controls the hot gas bypass valve to operate.

[0085] After steps 216 and 217 , the current anti-surge process ends and the process returns to step 201 .

[0086] It can be seen that in the present embodiment, the compressor includes a hot gas bypass valve, and when the operating state of the compressor meets the conditions for entering compressor surge, more high-pressure side gas can be bypassed to the low-pressure side by maintaining or increasing the opening of the compressor guide vane and the hot gas bypass valve, thereby increasing the pressure on the low-pressure side, thereby reducing the compression ratio of the compressor and further reducing the probability of compressor surge.

[0087] In this embodiment, the compressor not only uses the hot gas bypass valve to perform anti-surge control, but also performs energy regulation control by adjusting the hot gas bypass valve. In addition, anti-surge control takes precedence over energy regulation control. Therefore, after step 216 or step 217, the compressor can perform energy regulation control. The energy regulation function of the compressor is turned on.

[0088] Figure 3 It is a flow chart of a compressor control method provided by an embodiment of the present disclosure.

[0089] like Figure 3 As shown, the compressor control process includes:

[0090] Step 301: The compressor monitors the hot gas bypass valve opening and the chilled water temperature at a set sampling period, and determines the current valve opening that is less than the set entry opening as the entry valve opening.

[0091] The current operating state of the compressor does not meet the requirements for compressor surge adjustment, that is, after step 216 or step 217, the operating parameters of the compressor continue to be detected, including: the opening of the hot gas bypass valve and the chilled water temperature.

[0092] Among them, the set entry opening = set minimum opening + h%.

[0093] Step 302: Determine whether the current number of consecutive occurrences of the inlet valve opening is greater than the set continuous number N. If yes, execute step 303; otherwise, execute step 310.

[0094] Step 303: Determine whether the first duration corresponding to the chilled water temperature being less than the first set temperature is greater than or equal to the first set time. If so, execute step 304; otherwise, execute step 307.

[0095] The first set time may be 10s, 12s, 15s, etc., and the first set temperature may be = target temperature - shutdown temperature difference + adjustable opening temperature T of the hot gas bypass valve.

[0096] Step 304: Determine whether the hot gas bypass valve is in a closed state. If so, execute step 305; otherwise, execute step 306.

[0097] Step 305: The compressor controls the hot gas bypass valve to operate at the minimum setting opening.

[0098] Step 306: The compressor determines the smaller value between (Vd2+p%) and the maximum set opening as the fourth adjustment opening, and controls the operation of the hot gas bypass valve according to the fourth adjustment opening.

[0099] Among them, Vd2 is the second current opening, and the setting range can be p%.

[0100] Step 307: Determine whether the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature. If yes, execute step 308; otherwise, execute step 309.

[0101] The sum of the first set temperature + the set temperature i° C. may be determined as the second set temperature.

[0102] Step 308: The compressor controls the hot gas bypass valve to maintain unchanged operation.

[0103] Step 309: Determine whether the second duration corresponding to the chilled water temperature being greater than the second set temperature is greater than or equal to the second set time. If so, execute step 311; otherwise, execute step 310.

[0104] Step 310: Determine whether the current number of times that the hot gas bypass valve opening is less than or equal to the inlet valve opening is greater than the set continuous number N. If yes, execute step 311; otherwise, return to step 301.

[0105] Step 311 : The compressor determines the larger value between (Vd2-q%) and 0 as the fifth adjustment opening, and controls the operation of the hot gas bypass valve according to the fifth adjustment opening. Return to step 301 .

[0106] Among them, Vd2 is the second current opening, and the setting range can be q%.

[0107] Since the anti-surge control takes precedence over the energy regulation control, after step 311 , the process returns to step 201 .

[0108] It can be seen that in this embodiment, the compressor can automatically adjust the opening, holding and closing states of the hot gas bypass valve according to parameters such as the chilled water temperature, the target temperature, and the shutdown temperature difference to achieve energy regulation and reduce energy consumption. In addition, anti-surge control takes precedence over energy regulation control to ensure that when the anti-surge conditions are met, the hot gas bypass valve is controlled according to anti-surge first. This helps protect the compressor from surge damage and prolongs the life of the equipment. In addition, the maximum opening, minimum opening, adjustment range and other parameters of the hot gas bypass valve can be flexibly set, that is, the control parameters can be customized according to needs, and fine adjustment can be achieved, which also improves the operating efficiency and stability of the compressor.

[0109] According to the above process for compressor control, a device for compressor control can be constructed.

[0110] Figure 4 is a schematic diagram of a structure of a compressor control device provided by an embodiment of the present disclosure. The compressor includes a hot gas bypass valve, such as Figure 4 As shown, the compressor control device 400 includes: a first acquisition module 410 , a first adjustment module 420 and a first control module 430 .

[0111] The first acquisition module 410 is configured to acquire a first current opening of an intake guide vane in the compressor and a second current opening of a hot gas bypass valve when it is determined that the current operating state of the compressor meets a compressor surge condition.

[0112] The first adjustment module 420 is configured to maintain or increase the first current opening and the second current opening, and correspondingly obtain the first adjusted opening and the second adjusted opening.

[0113] The first control module 430 is configured to control the operation of the intake guide vane and the hot gas bypass valve in the compressor according to the first adjustment opening and the second adjustment opening, respectively.

[0114] In some embodiments, it also includes: a surge entry module, which is configured to monitor the current of the compressor with a set sampling period, obtain the current fluctuation rate corresponding to each sampling period, and determine the current fluctuation rate that is greater than the set current fluctuation rate as the first current fluctuation rate. When the current number of consecutive occurrences of the first current fluctuation rate is greater than the set number with the current moment as the end point, it is determined that the current operating state of the compressor meets the conditions for entering compressor surge; or, the current compression ratio of the compressor is obtained. When the current compression ratio is greater than the surge safety setting value, it is determined that the current operating state of the compressor meets the conditions for entering compressor surge.

[0115] In some embodiments, the first adjustment module 420 includes:

[0116] The first determination unit is configured to determine the second set opening as the first adjustment opening when the first current opening is less than or equal to the first set opening, and to determine the first current opening as the first adjustment opening when the first current opening is greater than the first set opening, wherein the second set opening is greater than the first set opening.

[0117] The second determination unit is configured to determine the third set opening as the second adjustment opening when the second current opening is less than or equal to the third set opening, and to determine the smaller value between the sum of the second current opening and the set increase value and the maximum set opening as the second adjustment opening when the second current opening is greater than the third set opening.

[0118] In some embodiments, it also includes: a second control module, which is configured to reduce the second current opening of the hot gas bypass valve to obtain a third adjusted opening when it is determined that the current operating state of the compressor meets the conditions for exiting compressor surge and when it is determined that the compressor has no load reduction request, and control the operation of the hot gas bypass valve according to the third adjusted opening.

[0119] In some embodiments, the second control module includes:

[0120] The third determining unit is configured to determine a fifth set opening as a third adjustment opening when the second current opening is smaller than the fourth set opening, wherein the fifth set opening is smaller than the fourth set opening.

[0121] The fourth determining unit is configured to determine the larger value between the difference between the second current opening and the set reduction value and the minimum set opening as the third adjustment opening when the second current opening is greater than or equal to the fourth set opening.

[0122] In some embodiments, it also includes:

[0123] A second acquisition module is configured to monitor the chilled water temperature of the compressor when it is determined that the current operating state of the compressor meets the compressor surge exit condition and the current operating state of the compressor meets the compressor low load entry condition;

[0124] The third control module is configured to control the hot gas bypass valve to start and increase operation when the first duration corresponding to the chilled water temperature is lower than the first set temperature is greater than or equal to the first set time; and to control the hot gas bypass valve to maintain unchanged operation when the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature.

[0125] In some embodiments, the third control module includes:

[0126] The first control unit is configured to control the hot gas bypass valve to operate at a minimum set opening when the hot gas bypass valve is in a closed state; when the hot gas bypass valve is in an operating state, determine the smaller value between the sum of the second current opening of the hot gas bypass valve and the set amplitude and the maximum set opening as a fourth adjustment opening, and control the operation of the hot gas bypass valve according to the fourth adjustment opening.

[0127] In some embodiments, it also includes:

[0128] The fourth control module is configured to, when it is determined that the current operating state of the compressor meets the conditions for exiting the compressor low load, determine the larger value of the difference between the second current opening of the hot gas bypass valve and the set amplitude and 0 as the fifth adjustment opening, and control the operation of the hot gas bypass valve according to the fifth adjustment opening, if the second duration corresponding to the chilled water temperature is greater than the second set temperature is greater than or equal to the second set time.

[0129] The compressor control process for the compressor control device is further described below in conjunction with the embodiments.

[0130] In this embodiment, the first setting opening a% can be 40%, the second setting opening c% can be 50%, the third setting opening b% can be 50%, the setting increase value d% can be 20%, the fourth setting opening e% can be 30%, the fifth setting opening f% can be 10%, and the setting decrease value g% can be 10%.

[0131] Figure 5 Schematic diagram of a compressor control device provided by an embodiment of the present disclosure. Figure 5 As shown, the compressor control device 400 includes: a first acquisition module 410 , a first adjustment module 420 , and a first control module 430 , and further includes: a surge entry module 440 , a second control module 450 , a second acquisition module 460 , a third control module 470 , and a fourth control module 480 .

[0132] In this embodiment, during the operation of the compressor, a sampling period is set to monitor the operating parameters of the compressor, including: the compressor current, compression ratio, intake guide vane opening, hot gas bypass valve opening, chilled water temperature, etc., and the current fluctuation rate corresponding to each sampling period can be obtained.

[0133] In this way, if the first current fluctuation rate appears n times in succession, where the first current fluctuation rate is greater than the current setting fluctuation rate, the surge entry module 440 can determine that the current operating state of the compressor meets the conditions for entering compressor surge, or, if the monitored current compression ratio is greater than the surge safety setting value, the surge entry module 440 can also determine that the current operating state of the compressor meets the conditions for entering compressor surge.

[0134] At this time, the first acquisition module 410 acquires the first current opening Vd1 of the intake guide vane in the compressor and the second current opening Vd2 of the hot gas bypass valve. If Vd1≤40%, the first adjustment module 420 may determine 50% as the first adjustment opening, and if Vd1>40%, the first adjustment module 420 may determine the first current opening as the first adjustment opening, so that the first control module 430 controls the operation of the intake guide vane according to the first adjustment opening.

[0135] If Vd2≤50%, the first adjustment module 420 may determine 50% as the second adjustment opening; otherwise, the first adjustment module 420 may determine the smaller value between (Vd2+20%) and the maximum set opening as the second adjustment opening, so that the first control module 430 may control the operation of the hot gas bypass valve according to the second adjustment opening.

[0136] If the duration of the first current fluctuation rate not occurring for n consecutive times is greater than 300s, or the duration of the compression ratio being less than or equal to the surge safety setting value is less than 300s, and there is no load reduction requirement for the compressor, the second control module 450 can reduce the second current opening of the hot gas bypass valve to obtain a third adjustment opening, and control the operation of the hot gas bypass valve according to the third adjustment opening. Wherein, when Vd2<30%, the second control module 450 can determine 10% as the third adjustment opening and control the operation of the hot gas bypass valve. Otherwise, the second control module 450 can determine the larger value between (Vd2-10%) and the minimum setting opening as the third adjustment opening and control the operation of the hot gas bypass valve.

[0137] The current running state of the compressor does not meet the compressor surge entry condition, that is, meets the compressor surge exit condition. At this time, if it is detected that the hot gas bypass valve opening is less than the set entry opening for N consecutive times, it can be determined to enter energy control. The second acquisition module 460 acquires the chilled water temperature of the compressor.

[0138] If the first duration corresponding to the chilled water temperature being less than the first set temperature is greater than or equal to the first set time, the third control module 470 may control the hot gas bypass valve to start increasing operation. If the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature, the third control module 470 controls the hot gas bypass valve to maintain unchanged operation. When controlling the hot gas bypass valve to start increasing operation, if the hot gas bypass valve is in a closed state, the third control module 470 controls the hot gas bypass valve to operate with a minimum set opening. If the hot gas bypass valve is in an operating state, the third control module 470 determines the smaller value between (Vd2+p%) and the maximum set opening as the fourth adjustment opening, and controls the operation of the hot gas bypass valve according to the fourth adjustment opening. Vd2 is the second current opening, and the setting range can be p%.

[0139] If the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature, the third control module 470 may control the hot gas bypass valve to maintain unchanged operation.

[0140] If the second duration corresponding to the chilled water temperature being greater than the second set temperature is greater than or equal to the second set time, or the current number of times that the hot gas bypass valve opening is less than or equal to the inlet valve opening appears continuously is greater than the set duration number N, then it is necessary to exit energy control. At this time, the fourth control module 480 determines the larger value between (Vd2-q%) and 0 as the fifth adjustment opening, and controls the operation of the hot gas bypass valve according to the fifth adjustment opening. Among them, Vd2 is the second current opening, and the setting range can be q%.

[0141] It can be seen that in this embodiment, the compressor is equipped with a hot gas bypass valve. Therefore, the device for controlling the compressor can use the hot gas bypass valve to perform anti-surge control to ensure the stable operation of the compressor under various working conditions. In addition, the device for controlling the compressor can also use the hot gas bypass valve to achieve energy regulation and reduce energy consumption. In addition, anti-surge control takes precedence over energy regulation control to ensure that when the anti-surge conditions are met, the hot gas bypass valve is controlled according to anti-surge first. This helps to protect the compressor from surge damage and extend the life of the equipment. In addition, the maximum opening, minimum opening, adjustment range and other parameters of the hot gas bypass valve can be flexibly set, that is, the control parameters can be customized according to needs, and fine adjustment can be achieved, which also improves the operating efficiency and stability of the compressor.

[0142] Combination Figure 6 , the embodiment of the present disclosure provides a device 600 for compressor control, comprising:

[0143] The processor 1000 and the memory 1001 may also include a communication interface 1002 and a bus 1003. The processor 1000, the communication interface 1002, and the memory 1001 may communicate with each other through the bus 1003. The communication interface 1002 may be used for information transmission. The processor 1000 may call the logic instructions in the memory 1001 to execute the method for compressor control of the above embodiment.

[0144] In addition, the logic instructions in the above-mentioned memory 1001 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0145] The memory 1001 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 1000 executes the function application and data processing by running the program instructions / modules stored in the memory 1001, that is, the method for compressor control in the above method embodiment is implemented.

[0146] The memory 1001 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 1001 may include a high-speed random access memory and may also include a non-volatile memory.

[0147] An embodiment of the present disclosure provides a compressor control device, including: a processor and a memory storing program instructions, wherein the processor is configured to execute a compressor control method when executing the program instructions.

[0148] Combination Figure 7 , the embodiment of the present disclosure provides a device 700, including: a device body, and the above-mentioned compressor control device 400 (600). The compressor control device 400 (600) is installed on the device body. The installation relationship described here is not limited to placement inside the product, but also includes installation connections with other components of the product, including but not limited to physical connections, electrical connections or signal transmission connections. It can be understood by those skilled in the art that the compressor control device 500 (600) can be adapted to a feasible device body, thereby realizing other feasible embodiments.

[0149] The device 700 may be a compressor unit including a compressor control device, or the device may be a central air conditioner, a condensing unit, etc. equipped with a compressor unit.

[0150] An embodiment of the present disclosure provides a storage medium storing program instructions, which, when run, execute the above-mentioned method for compressor control.

[0151] An embodiment of the present disclosure provides a computer program product, which includes a computer program stored on a storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the above-mentioned compressor control method.

[0152] The above-mentioned storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0153] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes, or a transient storage medium.

[0154] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible changes. Unless explicitly required, individual components and functions are optional, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of the present disclosure includes the entire scope of the claims, and all available equivalents of the claims. When used in this application, although the terms "first", "second", etc. may be used in this application to describe each element, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without changing the meaning of the description, the first element can be called the second element, and similarly, the second element can be called the first element, as long as all occurrences of the "first element" are renamed consistently and all occurrences of the "second element" are renamed consistently. The first element and the second element are both elements, but may not be the same element. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates, the singular forms "a", "an" and "the" are intended to include the plural forms as well. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listings. In addition, when used in this application, the term "comprise" and its variants "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups of these. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method or device including the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0155] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0156] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0157] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for compressor control, characterized in that: The compressor includes a hot gas bypass valve, the method comprising: When it is determined that the current operating state of the compressor meets the compressor surge condition, obtaining a first current opening degree of an intake guide vane in the compressor and a second current opening degree of a hot gas bypass valve; Maintain or increase the first current opening and the second current opening, and correspondingly obtain the first adjusted opening and the second adjusted opening; According to the first adjustment opening and the second adjustment opening, the operation of the air intake guide vane and the hot gas bypass valve in the compressor are controlled respectively.

2. The method according to claim 1, characterized in that Determining whether the current operating state of the compressor meets the compressor surge condition includes: The current of the compressor is monitored with a set sampling period to obtain the current fluctuation rate corresponding to each sampling period, and the current fluctuation rate greater than the set current fluctuation rate is determined as the first current fluctuation rate. When the current number of consecutive occurrences of the first current fluctuation rate is greater than the set number with the current moment as the end point, it is determined that the current operating state of the compressor meets the compressor surge condition; or, The current compression ratio of the compressor is obtained, and when the current compression ratio is greater than the surge safety setting value, it is determined that the current operating state of the compressor meets the compressor surge condition.

3. The method according to claim 1, characterized in that The obtaining of the first adjustment opening and the second adjustment opening comprises: When the first current opening is less than or equal to the first set opening, the second set opening is determined as the first adjustment opening, and when the first current opening is greater than the first set opening, the first current opening is determined as the first adjustment opening, wherein the second set opening is greater than the first set opening; When the second current opening is less than or equal to the third set opening, the third set opening is determined as the second adjustment opening, and when the second current opening is greater than the third set opening, the smaller value between the sum of the second current opening and the set increase value and the maximum set opening is determined as the second adjustment opening.

4. The method according to claim 1, characterized in that: Also includes: When it is determined that the current operating state of the compressor meets the conditions for exiting compressor surge, if it is determined that the compressor has no load reduction request, the second current opening of the hot gas bypass valve is reduced to obtain a third adjusted opening, and the operation of the hot gas bypass valve is controlled according to the third adjusted opening.

5. The method according to claim 4, characterized in that The obtaining of the third adjustment opening comprises: In the case where the second current opening is smaller than the fourth set opening, determining the fifth set opening as the third adjustment opening, wherein the fifth set opening is smaller than the fourth set opening; When the second current opening is greater than or equal to the fourth set opening, a larger value between a difference between the second current opening and the set reduction value and the minimum set opening is determined as the third adjustment opening.

6. The method according to any one of claims 1 to 5, characterized in that: Also includes: When it is determined that the current operating state of the compressor meets the compressor surge exit condition and the current operating state of the compressor meets the compressor low load entry condition, monitoring the chilled water temperature of the compressor; When the first duration corresponding to the chilled water temperature being lower than the first set temperature is greater than or equal to the first set time, the hot gas bypass valve is controlled to start increasing operation; When the chilled water temperature is greater than or equal to the first set temperature and less than or equal to the second set temperature, the hot gas bypass valve is controlled to maintain unchanged operation.

7. The method according to claim 6, characterized in that The control of the hot gas bypass valve to start increasing operation includes: When the hot gas bypass valve is in a closed state, the hot gas bypass valve is controlled to operate at a minimum set opening; When the hot gas bypass valve is in operation, the smaller value between the sum of the second current opening of the hot gas bypass valve and the set amplitude and the maximum set opening is determined as the fourth adjustment opening, and the operation of the hot gas bypass valve is controlled according to the fourth adjustment opening.

8. The method according to claim 6, characterized in that Also includes: When it is determined that the current operating state of the compressor meets the conditions for exiting the compressor low load, if the chilled water temperature is greater than the second set temperature and the second duration corresponding to the temperature is greater than or equal to the second set time, the larger value of the difference between the second current opening of the hot gas bypass valve and the set amplitude and 0 is determined as the fifth adjustment opening, and the operation of the hot gas bypass valve is controlled according to the fifth adjustment opening.

9. A device for compressor control, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to perform the method for compressor control according to any one of claims 1 to 8 when executing the program instructions.

10. A device, characterized in that: include: Equipment body; The device for compressor control as claimed in claim 9 is installed on the equipment body.

11. A storage medium storing program instructions, characterized in that: When the program instructions are executed, the method for compressor control as described in any one of claims 1 to 8 is executed.

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