Control method, device and system of centrifugal air compressor and medium

Abstract

The invention discloses a centrifugal air compressor control method, device and system and a medium, and the method comprises the steps that in response to an operation request of a centrifugal air compressor, a first-stage air inlet temperature value, a first-stage air inlet pressure value and a last-stage exhaust pressure value of the centrifugal air compressor are obtained; determining a pressure head of the centrifugal air compressor based on the first-stage air inlet temperature value, the first-stage air inlet pressure value and the final-stage exhaust pressure value; and controlling the centrifugal air compressor to work based on the pressure head. In the production process of the centrifugal air compressor, the pressure head serves as the minimum load / maximum load control value to control the air compressor to work, surge of the centrifugal air compressor is avoided, a bypass valve does not need to be used for deflating, the centrifugal air compressor always operates under the stable and efficient working condition, unnecessary energy loss is reduced, and the service life of the centrifugal air compressor is prolonged. Energy consumption is reduced, and operation cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of air compressors, and particularly to a control method, device, system and medium for a centrifugal air compressor. Background Art

[0002] In the related art, during the production process of a centrifugal air compressor, to prevent surging, the inlet valve is restricted to a fixed opening degree, so that the gas exceeding the flow rate needs to be converted into the atmosphere through a bypass valve, resulting in energy loss. Summary of the Invention

[0003] The present invention provides a control method, device, system and medium for a centrifugal air compressor to solve the technical problem that during the production process of a centrifugal air compressor, to prevent surging, the inlet valve is restricted to a fixed opening degree, so that the gas exceeding the flow rate needs to be converted into the atmosphere through a bypass valve, resulting in energy loss.

[0004] In a first aspect, a control method for a centrifugal air compressor is provided, including:

[0005] Responding to a running request of the centrifugal air compressor, obtaining the primary inlet air temperature value, primary inlet air pressure value and final stage exhaust pressure value of the centrifugal air compressor;

[0006] Based on the primary inlet air temperature value, primary inlet air pressure value and final stage exhaust pressure value, determining the head of the centrifugal air compressor;

[0007] Based on the head, controlling the operation of the centrifugal air compressor.

[0008] In a second aspect, a control device for a centrifugal air compressor is provided, including:

[0009] An obtaining module, configured to respond to a running request of the centrifugal air compressor and obtain the primary inlet air temperature value, primary inlet air pressure value and final stage exhaust pressure value of the centrifugal air compressor;

[0010] A determining module, configured to determine the head of the centrifugal air compressor based on the primary inlet air temperature value, primary inlet air pressure value and final stage exhaust pressure value;

[0011] A control module, configured to control the operation of the centrifugal air compressor based on the head.

[0012] In a third aspect, a centrifugal air compressor control system is provided, including:

[0013] At least one centrifugal air compressor;

[0014] Each centrifugal air compressor includes:

[0015] An inlet valve;

[0016] A controller, communicatively connected to at least one centrifugal air compressor, is configured to adjust the opening degree of an intake valve.

[0017] In a fourth aspect, a readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps of the above control method of the centrifugal air compressor are implemented.

[0018] In the solution implemented by the above control method, device, system and storage medium of the centrifugal air compressor, during the production process of the centrifugal air compressor, the head is calculated by collecting the first-stage intake temperature, first-stage intake pressure and last-stage exhaust pressure of the centrifugal air compressor in real time, and the head is used as the minimum load / maximum load control value to control the operation of the air compressor, avoiding surging of the centrifugal air compressor and eliminating the need to use a bypass valve for air release. While the centrifugal air compressor always operates under stable and efficient working conditions, unnecessary energy losses are reduced, energy consumption is lowered, and operating costs are saved. Description of the Drawings

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic flowchart of a control method of a centrifugal air compressor according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of a centrifugal air compression anti-surge control curve according to an embodiment of the present invention;

[0022] Figure 3 is a schematic structural diagram of a control device of a centrifugal air compressor according to an embodiment of the present invention. Detailed Embodiments

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It should be understood that the drawings in the present invention are only for the purpose of illustration and description, and are not used to limit the protection scope of the present invention.

[0024] In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present invention illustrate operations implemented according to some embodiments of the present invention. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present invention.

[0025] In addition, the embodiments described in the present invention are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention usually described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but only represents the selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0026] It should be noted that the term "comprising" will be used in the embodiments of the present invention to indicate the presence of the features stated hereinafter, but does not exclude the addition of other features. It should also be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] The following will describe this case in detail in conjunction with the relevant drawings of the specification.

[0028] In the embodiments of this specification, surge is a unique phenomenon that occurs when a centrifugal air compressor operates under a certain working condition. When the air flow rate entering the air compressor cannot enable the air compressor to generate sufficient pressure, so that the pressure of the external system (external pipeline) is greater than the pressure inside the air compressor, the check valve closes. At this time, the air compressor has no output, and air accumulates inside the air compressor, and the pressure continuously increases until the accumulated pressure is greater than the pressure of the external system, and the internal pressure of the air compressor blows open the check valve and discharges. After the gas is discharged, since there is not enough air to enable the air compressor to maintain continuous output, the internal pressure of the air compressor drops, the check valve closes, and air accumulates inside the air compressor again until the accumulated pressure is sufficient, and then it is discharged again. Repeating like this, it causes the output pressure and the motor load to fluctuate violently, the check valve to act frequently, and the machine to make a thumping sound. This phenomenon is called surge.

[0029] Thus, it can be seen that when the exhaust gas flow rate of a centrifugal air compressor suddenly drops or decreases to a certain extent, the resulting air flow reflux may trigger surge of the unit. The strong vibration of the unit brought about during surge will cause serious damage to the bearings, seals, etc. of the unit.

[0030] At present, there are two surge control strategies for centrifugal air compressors. One is to fix the position of the intake valve during the production process of the centrifugal air compressor, so that the intake valve is restricted to a fixed opening degree to prevent it from closing further. As a result, the gas exceeding the flow rate needs to be transferred to the atmosphere through the bypass valve, which causes energy loss. The other is to adopt the method of limiting the current to control the minimum load, which essentially controls the power input of the air compressor and then controls its operating conditions. Because to a certain extent, there is a correlation between the motor current and the flow rate of the air compressor. When the flow rate increases, the air compressor needs to do more work to compress more gas, so the motor current increases; conversely, when the flow rate decreases, the required power decreases and the current also decreases accordingly. By setting the lower limit value of the current, it is ensured that the air compressor operates under a relatively stable load state, avoiding entering the surge area due to too low a flow rate. However, this situation means that when the voltage fluctuates, the energy consumption cannot be effectively reduced. Enterprises need to pay more electricity bills to maintain the operation of the air compressor, increasing the production cost. Moreover, in the general environment of advocating energy conservation and emission reduction, the non-energy-saving operation mode does not meet the requirements of sustainable development. In addition, when the voltage drops, according to the characteristics of the motor, in order to maintain the operation of the air compressor, the motor needs to output a relatively stable power. When the voltage decreases, the current will increase accordingly. However, the voltage drop may cause the output torque of the motor to decrease, resulting in a tendency for the impeller speed of the air compressor to decrease. Although the flow rate remains temporarily unchanged at this time, if the voltage continues to drop or the drop amplitude is large, the impeller speed will decrease significantly, resulting in a decrease in the flow rate of the compressor. When the flow rate decreases below the surge flow rate, a surge phenomenon will be triggered.

[0031] Based on the above problems, this application proposes an efficient energy-saving control method for centrifugal air compressors. Using a variable pressure head, the calculated pressure head replaces the motor current measurement value as the minimum load control value. In actual production, the operating conditions of the compressor may change due to changes in intake conditions (such as temperature, pressure, gas composition, etc.). The correlation between the motor current and these intake conditions is not close, and it is difficult to accurately reflect the surge risk of the compressor according to the change of operating conditions; while the pressure head is directly related to the intake conditions and can reflect the working state of the compressor in real time as the operating conditions change, thus more effectively preventing surges.

[0032] Please refer to Figure 1 , this embodiment of the specification provides a control method for a centrifugal air compressor, and the method specifically includes the following steps:

[0033] S10: In response to the operation request of the centrifugal air compressor, obtain the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value of the centrifugal air compressor.

[0034] It can be understood that the execution subject of the present invention can be an LC-MS peak detection device, or a terminal or a server. Specifically, it is not limited here. In the embodiments of the present invention, the server is taken as the execution subject for illustration.

[0035] In this step, when a running request of a centrifugal air compressor (referred to as a centrifugal air compressor for short) is received, the centrifugal air compressor is started. During the operation of the centrifugal air compressor, the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust air pressure value of the centrifugal air compressor are collected in real time. Among them, the first-stage intake air temperature value refers to the temperature when air enters the first-stage compression chamber of the centrifugal air compressor; the first-stage intake air pressure value refers to the pressure when air enters the first-stage compression chamber of the centrifugal air compressor; the last-stage exhaust air pressure value refers to the pressure when air is discharged from the last-stage compression chamber of the centrifugal air compressor after multi-stage compression.

[0036] S20: Determine the head of the centrifugal air compressor based on the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust air pressure value.

[0037] In this step, the head refers to the energy increment obtained by a unit weight of fluid in the compressor, which reflects the compression ability of the compressor for air. In a centrifugal air compressor, the head reflects the work done by the air compressor to compress air from the intake state to the exhaust state. In actual production, the operating conditions of the centrifugal air compressor may change due to changes in intake conditions (such as temperature, pressure, etc.). The head is directly related to the intake conditions and can reflect the working state of the centrifugal air compressor in real time as the operating conditions change. Taking the head as the control value, the load of the centrifugal air compressor can be accurately adjusted. In addition, by introducing the last-stage exhaust air pressure for calculating the head, the last-stage exhaust air pressure directly reflects the final effect of the compression process of the centrifugal air compressor, enabling the calculation of the head to more comprehensively reflect the actual working state of the air compressor, and further enabling the control and monitoring based on the head to more accurately determine whether the compressor is approaching the surge boundary. Therefore, calculate the head through the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust air pressure value during the operation of the centrifugal air compressor to monitor the working state of the centrifugal compressor.

[0038] In an embodiment of the present application, a specific head calculation scheme is provided. In S20, that is, determine the head of the centrifugal air compressor based on the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust air pressure value, which specifically includes:

[0039] Input the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust air pressure value into the head calculation formula to calculate the head of the air compressor;

[0040] Among them, the head calculation formula is:

[0041]

[0042] Wherein, T H is the inlet air temperature value of the first stage, unit: degree Fahrenheit; P2 is the exhaust pressure value of the last stage, unit: PSI (pound-force per square inch); P1 is the inlet air pressure value of the first stage, unit: PSI (pound-force per square inch).

[0043] In this embodiment, during the multi-stage compression of the centrifugal air compressor, there are differences in the inlet air temperature of each stage. In the inlet air state of the stage with the highest temperature (i.e., the first stage), the gas density is lower and the compressibility is greater. The air compressor needs to overcome greater resistance to increase the pressure, and at this time, surging is most likely to be triggered. Therefore, considering the states of the cooling water and the air cooler, using this temperature to calculate the head can accurately simulate the operating conditions of the compressor under the most severe working conditions, making the calculated head closer to the critical value when surging actually occurs, thereby more accurately defining the surging boundary. Further, the inlet air pressure of the first stage is the initial pressure condition in the compression process of the centrifugal air compressor, which directly affects the compression ratio and head requirements of the subsequent stages. Considering the pressure drop of the pipeline and the inlet filter, accurately obtaining the inlet air pressure of the first stage and using it for head calculation and surging control can avoid the decline of system performance or equipment damage caused by the fluctuation of the inlet air pressure. Furthermore, the exhaust pressure of the last stage directly reflects the ability of the air compressor to overcome the system resistance and compress the gas to the required pressure, which is closely related to the surging phenomenon. When the exhaust pressure of the last stage is too high and the flow rate is insufficient, surging is likely to be triggered.

[0044] By the above method, introducing the inlet air temperature of the stage with the highest temperature, the inlet air pressure of the first stage, and the exhaust pressure of the last stage to calculate the head provides strong support for the effective prevention and control of surging.

[0045] S30: Control the centrifugal air compressor based on the head.

[0046] In this step, by adjusting the operating parameters of the centrifugal air compressor, the head is kept within a reasonable range, avoiding surging caused by too high or too low head. At the same time, based on the precise control of the head, it can ensure that the pressure and flow rate of the compressed air output by the centrifugal air compressor just meet the actual needs, without generating unnecessary excessive gas, thereby achieving energy conservation.

[0047] In an embodiment of the present application, a specific control scheme for the centrifugal air compressor is provided. In S30, that is, controlling the centrifugal air compressor based on the head, specifically includes the following steps S31 - S32:

[0048] S31: Compare the head with the first preset head threshold corresponding to the minimum load state and the second preset head threshold corresponding to the maximum load state.

[0049] S32: Adjust the opening degree of the intake valve of the air compressor based on the comparison result.

[0050] For steps S31 - S32, in a centrifugal compressor, there is a specific performance curve relationship between gas flow and head. The first preset head threshold corresponds to the minimum load state of the centrifugal air compressor and is the lower limit of the head value that ensures the centrifugal air compressor can operate stably and meet the minimum process requirements. When the head approaches or is lower than this threshold, it indicates that the load of the air compressor is too low, the gas flow may be insufficient, and the centrifugal air compressor may experience a surge phenomenon; the second preset head threshold corresponds to the maximum load state of the centrifugal air compressor and is the upper limit of the head value that the air compressor can reach within the safe operating range. When the head approaches or is higher than this threshold, it means that the load of the air compressor is too high, which means that the air compressor needs to overcome greater resistance to increase the gas pressure. At a certain rotational speed, if too high a head is to be achieved, the gas flow will decrease accordingly. When the flow rate decreases to the surge flow rate, the air flow inside the compressor becomes unstable, prone to rotational detachment, and thus a surge is triggered. The opening degree of the intake valve of the centrifugal air compressor directly affects the gas flow entering the air compressor. Based on the calculated head as the minimum load / maximum load control value, the opening degree of the intake valve is adjusted. By continuously fine-tuning the intake air volume, the head is stabilized within a suitable range, avoiding large fluctuations in head and flow rate, thereby effectively suppressing the inducement of surges and enabling the air compressor to always operate in a stable operating area (i.e., avoiding the surge line).

[0051] Optionally, the anti-surge control of the centrifugal air compressor uses the head as the control value. R & D personnel can set the minimum load head set value (i.e., the first preset head threshold) and the maximum load head set value (i.e., the second preset head threshold) according to the characteristics of the centrifugal air compressor, system requirements, and safety margin. This application does not make specific limitations here.

[0052] In an embodiment of the present application, a specific intake valve opening degree adjustment scheme is provided. In S32, that is, based on the comparison result, the opening degree of the intake valve of the centrifugal air compressor is adjusted, which specifically includes the following steps:

[0053] When the head is less than or equal to the first preset head threshold, obtain the motor current value of the centrifugal air compressor;

[0054] Based on the motor current value and the first preset current set value, through the proportional-integral-derivative control strategy, reduce the opening degree of the intake valve until the head is greater than the first preset head threshold and less than the second preset head threshold, and then stop adjusting the opening degree of the intake valve.

[0055] In this embodiment, during the production process, the head of the centrifugal air compressor is continuously monitored. When it is detected that the head is less than or equal to the first preset head threshold corresponding to the minimum load state, intervention is required at this time to avoid equipment surge. Specifically, the real-time motor current value is obtained. The magnitude of this current is directly related to the load of the centrifugal air compressor. According to the current difference between the real-time current value and the first preset current setting value, through proportional (P)-integral (I)-differential (D) operation, an adjustment signal is generated to drive the intake valve to reduce the opening degree, limit the air intake flow of the air compressor, and thus gradually increase the head. The adjustment is cycled until the head is within the safe range, that is, the first preset head threshold < real-time head < second preset head threshold.

[0056] In an embodiment of the present application, a specific intake valve opening adjustment scheme is provided. In S32, that is, based on the comparison result, the opening degree of the intake valve of the centrifugal air compressor is adjusted, which specifically includes the following steps:

[0057] When the head is greater than or equal to the second preset head threshold, obtain the motor current value of the centrifugal air compressor;

[0058] Based on the motor current value and the second preset current setting value, through the proportional-integral-differential control strategy, increase the opening degree of the intake valve until the head is less than the second preset head threshold and greater than the first preset head threshold, and then stop adjusting the opening degree of the intake valve.

[0059] In this embodiment, during the production process, the head of the centrifugal air compressor is continuously monitored. When it is detected that the head is greater than or equal to the second preset head threshold corresponding to the maximum load state, obtain the real-time motor current value of the air compressor. According to the current deviation between the real-time motor current value and the second preset current setting value, through PID operation, an adjustment signal is generated to drive the intake valve to increase the opening degree and reduce the head. The adjustment is cycled until the head is within the safe range, that is, the first preset head threshold < real-time head < second preset head threshold.

[0060] In the above manner, the head is used as the control value, and the head is indirectly controlled through current feedback. Combining the robustness of PID (proportional-integral-differential control strategy), it is ensured that the air compressor approaches the surge zone wirelessly without surging.

[0061] In actual application scenarios, such as Figure 2As shown, it is a schematic diagram of the anti-surge control curve of a centrifugal air compressor. In the figure, the abscissa represents the flow rate, indicating the gas volume flow rate of the air compressor; the ordinate represents the head. The natural surge point on the left side of the curve is the minimum flow rate point. Below this point, the air compressor enters the surge zone. The anti-surge control line set by the R & D personnel is between the minimum load process / control set value (Minload_SP) on the right side of the natural surge point and the natural surge point, which is used to reserve a safety margin. When it is summer, T H (the primary inlet air temperature value) increases, and the head (Minload_CV) shows an upward trend. The PID controller automatically increases the opening of the inlet valve to suppress the rise of the head and prevent surge. When it is winter, T H (the primary inlet air temperature value) decreases, and the opening of the inlet valve is reduced to save energy. In addition, due to system pressure fluctuations or an increase in the set pressure, the exhaust pressure increases, and the head shows an upward trend. The PID controller automatically increases the opening of the inlet valve to suppress the rise of the head and avoid surge. Conversely, when the exhaust pressure decreases, the opening of the inlet valve is reduced to save energy.

[0062] It can be seen that in the above solution, during the production process of the centrifugal air compressor, by collecting the primary inlet air temperature, primary inlet air pressure, and final stage exhaust pressure of the centrifugal air compressor in real time, the head is calculated, and the head is used as the minimum load / maximum load control value to control the operation of the air compressor, avoiding surge of the centrifugal air compressor and eliminating the need to use a bypass valve for bleeding. This enables the centrifugal air compressor to always operate under stable and efficient conditions, while reducing unnecessary energy losses, lowering energy consumption, and saving operating costs.

[0063] In one embodiment, a control device for a centrifugal air compressor is provided. The control device for the centrifugal air compressor corresponds one-to-one with the control method of the centrifugal air compressor in the above embodiment. As Figure 3 shown, the control device 100 of the centrifugal air compressor includes: an acquisition module 101, a determination module 102, and a control module 103. The detailed description of each functional module is as follows:

[0064] The acquisition module 101 is configured to obtain the primary inlet air temperature value, primary inlet air pressure value, and final stage exhaust pressure value of the centrifugal air compressor in response to an operation request of the centrifugal air compressor;

[0065] The determination module 102 is configured to determine the head of the centrifugal air compressor based on the primary inlet air temperature value, primary inlet air pressure value, and final stage exhaust pressure value;

[0066] The control module 103 is configured to control the operation of the centrifugal air compressor based on the head.

[0067] In one embodiment, the determination module 102 is specifically configured to:

[0068] Input the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust pressure value into the head calculation formula to calculate the head of the centrifugal air compressor;

[0069] Among them, the head calculation formula is:

[0070]

[0071] In one embodiment, the control module 103 is specifically configured to:

[0072] Compare the head with a first preset head threshold corresponding to the minimum load state and a second preset head threshold corresponding to the maximum load state;

[0073] Based on the comparison result, adjust the opening degree of the intake valve of the centrifugal air compressor.

[0074] In one embodiment, the control module 103 is further specifically configured to:

[0075] When the head is less than or equal to the first preset head threshold, obtain the motor current value of the centrifugal air compressor;

[0076] Based on the motor current value and the first preset current setting value, through the proportional-integral-derivative control strategy, reduce the opening degree of the intake valve until the head is greater than the first preset head threshold and less than the second preset head threshold, and then stop adjusting the opening degree of the intake valve.

[0077] In one embodiment, the control module 103 is further specifically configured to:

[0078] When the head is greater than or equal to the second preset head threshold, obtain the motor current value of the centrifugal air compressor;

[0079] Based on the motor current value and the second preset current setting value, through the proportional-integral-derivative control strategy, increase the opening degree of the intake valve until the head is less than the second preset head threshold and greater than the first preset head threshold, and then stop adjusting the opening degree of the intake valve.

[0080] The present invention provides a control device for a centrifugal air compressor, which calculates the head by collecting the first-stage intake air temperature, the first-stage intake air pressure, and the last-stage exhaust pressure of the centrifugal air compressor in real time, and uses the head as the minimum load / maximum load control value to control the operation of the air compressor, avoiding surging of the centrifugal air compressor and eliminating the need to use a bypass valve for bleeding, enabling the centrifugal air compressor to always operate under stable and efficient working conditions, while reducing unnecessary energy losses, lowering energy consumption, and saving operating costs.

[0081] For the specific limitations of the control device of the centrifugal air compressor, reference can be made to the limitations of the control method of the centrifugal air compressor in the foregoing text, which will not be elaborated herein. Each module in the control device of the above-mentioned centrifugal air compressor can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the electronic device in the form of hardware or be independent of it, or can be stored in the memory of the electronic device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0082] In one embodiment, a centrifugal air compressor control system is provided, which is applicable to the control method of the above-mentioned centrifugal air compressor. The system includes:

[0083] At least one centrifugal air compressor;

[0084] Each centrifugal air compressor includes:

[0085] An intake valve;

[0086] A controller, which is communicatively connected to at least one centrifugal air compressor, and the controller is used to adjust the opening degree of the intake valve.

[0087] A centrifugal air compressor control system provided by the present application. Specifically, the system includes one or more centrifugal air compressors. The intake valve is installed at the air inlet of each centrifugal air compressor and is used for the air flow entering the air compressor. The controller is communicatively connected to each centrifugal air compressor, and the opening degree of the intake valve is adjusted through the controller to avoid the air compressor from surging.

[0088] Optionally, the controller can be a PID controller. During the production process of the centrifugal air compressor, the PID controller calculates the head by receiving the first-stage intake temperature, first-stage intake pressure, and final-stage exhaust pressure of the air compressor, and takes the head as the minimum load / maximum load control value. The opening degree of the intake valve is adjusted through the proportional-integral-derivative control strategy, avoiding the centrifugal air compressor from surging and eliminating the need to use a bypass valve for air release. While the centrifugal air compressor always operates under stable and efficient working conditions, unnecessary energy losses are reduced, energy consumption is lowered, and operating costs are saved.

[0089] In one embodiment, each air compressor further includes:

[0090] An intake pipeline, which is connected to the intake valve;

[0091] A multi-stage compression assembly, where the multi-stage compression assembly includes a first-stage compression assembly (impeller) and a final-stage compression assembly;

[0092] A first temperature sensor, which is arranged on the intake pipeline;

[0093] A second temperature sensor, disposed on the last-stage compression assembly;

[0094] A pressure sensor, disposed on the intake pipe;

[0095] A motor;

[0096] A current transformer, disposed on the motor.

[0097] In this embodiment, for any centrifugal air compressor, the air compressor is provided with an intake pipe connected to an intake valve and a multi-stage compression assembly (such as an impeller). Among them, the multi-stage compression assembly includes a first-stage compression assembly communicating with the intake pipe and a last-stage compression assembly as the last stage of the multi-stage compression assembly. Further, the centrifugal air compressor further includes a temperature sensor and a pressure sensor. The first temperature sensor and the pressure sensor are disposed on the intake pipe to monitor the first-stage intake air temperature and the first-stage intake air pressure entering the first-stage compression assembly in real time; the second temperature sensor is disposed at the outlet end of the last-stage compression assembly to monitor the last-stage exhaust temperature. Furthermore, the centrifugal air compressor is also provided with a motor for providing rotational power for moving components such as the impeller, and a current transformer disposed on the motor for measuring the working current of the motor. During the production process of the centrifugal air compressor, by collecting the first-stage intake air temperature, the first-stage intake air pressure, and the last-stage exhaust pressure of the centrifugal air compressor in real time, the head is calculated, and the head is used as the minimum load / maximum load control value to control the operation of the air compressor, avoiding the surging of the centrifugal air compressor and eliminating the need to use a bypass valve for air release, enabling the centrifugal air compressor to always operate under stable and efficient working conditions, while reducing unnecessary energy losses, lowering energy consumption, and saving operating costs.

[0098] The centrifugal air compressor control system provided by this application automatically and precisely adjusts the opening degree of the air valve through a PID controller according to the change of the real-time head, enabling the centrifugal air compressor to approach the surge zone infinitely without surging, saving energy while preventing surging.

[0099] In one embodiment, the centrifugal air compressor control system further includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0100] In response to a running request of the centrifugal air compressor, obtain the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust pressure value of the centrifugal air compressor;

[0101] Based on the first-stage intake air temperature value, the first-stage intake air pressure value, and the last-stage exhaust pressure value, determine the head of the centrifugal air compressor;

[0102] Based on the head, control the operation of the centrifugal air compressor.

[0103] In one embodiment, a readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0104] In response to a running request of a centrifugal air compressor, obtain the head inlet air temperature value, the head inlet air pressure value, and the last stage exhaust pressure value of the centrifugal air compressor;

[0105] Based on the head inlet air temperature value, the head inlet air pressure value, and the last stage exhaust pressure value, determine the head of the centrifugal air compressor;

[0106] Based on the head, control the operation of the centrifugal air compressor.

[0107] It should be noted that for the functions or steps that the above-readable storage medium can achieve, reference can be made to the relevant descriptions on the server side and the client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0108] Those of ordinary skill in the art can understand that to implement all or part of the processes in the above method embodiments, it can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0109] Those skilled in the art can clearly understand that for the convenience and brevity of description, only the above division of each functional unit and module is used as an example. In practical applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

[0110] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for a centrifugal air compressor, characterized in that, Including: In response to a running request of a centrifugal air compressor, obtaining the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value of the centrifugal air compressor; Based on the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value, determining the head of the centrifugal air compressor; Based on the head, controlling the operation of the centrifugal air compressor.

2. The method according to claim 1, wherein The step of determining the head of the centrifugal air compressor based on the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value specifically includes: Inputting the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value into a head calculation formula to calculate the head of the centrifugal air compressor; Wherein, the head calculation formula is:

3. The method according to claim 1, wherein The step of controlling the operation of the centrifugal air compressor based on the head specifically includes: Comparing the head with a first preset head threshold value corresponding to the minimum load state and a second preset head threshold value corresponding to the maximum load state; Based on the comparison result, adjusting the opening degree of the intake valve of the centrifugal air compressor.

4. The method according to claim 3, characterized in that The step of adjusting the opening degree of the intake valve of the centrifugal air compressor based on the comparison result specifically includes: When the head is less than or equal to the first preset head threshold value, obtaining the motor current value of the centrifugal air compressor; Based on the motor current value and a first preset current setting value, through a proportional-integral-derivative control strategy, reducing the opening degree of the intake valve until the head is greater than the first preset head threshold value and less than the second preset head threshold value, and then stopping adjusting the opening degree of the intake valve.

5. The method according to claim 3, wherein The step of adjusting the opening degree of the intake valve of the centrifugal air compressor based on the comparison result specifically further includes: When the head is greater than or equal to the second preset head threshold value, obtaining the motor current value of the centrifugal air compressor; Based on the motor current value and a second preset current setting value, through a proportional-integral-derivative control strategy, increasing the opening degree of the intake valve until the head is less than the second preset head threshold value and greater than the first preset head threshold value, and then stopping adjusting the opening degree of the intake valve.

6. A control device for a centrifugal air compressor, characterized in that, Including: An acquisition module, configured to obtain the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value of the centrifugal air compressor in response to a running request of the centrifugal air compressor; A determination module, configured to determine the head of the centrifugal air compressor based on the primary intake air temperature value, the primary intake air pressure value, and the final stage exhaust pressure value; A control module, configured to control the operation of the centrifugal air compressor based on the head.

7. A centrifugal air compressor control system, characterized in that, Applicable to the control method of the centrifugal air compressor according to any one of claims 1 to 5, the system includes: At least one centrifugal air compressor; Each centrifugal air compressor includes: An intake valve; A controller, communicatively connected to the at least one centrifugal air compressor, and the controller is configured to adjust the opening degree of the intake valve.

8. The centrifugal air compressor control system according to claim 7, wherein, Each centrifugal air compressor further includes: An intake pipeline, connected to the intake valve; Multistage compression assembly, wherein the multistage compression assembly includes a first-stage compression assembly and a last-stage compression assembly; A first temperature sensor, disposed on the intake duct; A second temperature sensor, disposed on the last-stage compression assembly; A pressure sensor, disposed on the intake duct; A motor; A current transformer, disposed on the motor.

9. The centrifugal air compressor control system according to claim 7, wherein Further included are: A memory that stores programs or instructions; A processor, connected to the memory, and when the processor executes the programs or instructions, it implements the control method of the centrifugal air compressor according to any one of claims 1 to 5.

10. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method of the centrifugal air compressor according to any one of claims 1 to 5.

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