Control methods, devices, systems and media for centrifugal air compressors

Abstract

This invention discloses a control method, device, system, and medium for a centrifugal air compressor. The method includes: in response to an operating request from the centrifugal air compressor, acquiring the first-stage inlet temperature, first-stage inlet pressure, and final-stage exhaust pressure of the centrifugal air compressor; determining the compressor head based on the first-stage inlet temperature, first-stage inlet pressure, and final-stage exhaust pressure; and controlling the operation of the centrifugal air compressor based on the compressor head. During the production process of the centrifugal air compressor, by controlling the compressor operation using the compressor head as the minimum / maximum load control value, surge in the centrifugal air compressor is avoided, and the use of a bypass valve for venting is eliminated. This ensures that the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs.

Description

Technical Field

[0001] This invention relates to the field of air compressor technology, and in particular to a control method, device, system and medium for a centrifugal air compressor. Background Technology

[0002] In related technologies, to prevent surge during the production of centrifugal air compressors, the intake valve is restricted to a fixed opening, requiring excess gas to be diverted to the atmosphere via a bypass valve, resulting in energy loss. Summary of the Invention

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

[0004] Firstly, a control method for a centrifugal air compressor is provided, including:

[0005] In response to the operation request of the centrifugal air compressor, the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust pressure of the centrifugal air compressor are obtained.

[0006] The head of the centrifugal air compressor is determined based on the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust air pressure.

[0007] The operation of the centrifugal air compressor is controlled based on the pressure head.

[0008] Secondly, a control device for a centrifugal air compressor is provided, comprising:

[0009] The acquisition module is used to acquire the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust air pressure value of the centrifugal air compressor in response to the operation request of the centrifugal air compressor.

[0010] The determination module is used to determine the head of the centrifugal air compressor based on the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value.

[0011] The control module is used to control the operation of the centrifugal air compressor based on the pressure head.

[0012] Thirdly, a centrifugal air compressor control system is provided, comprising:

[0013] At least one centrifugal air compressor;

[0014] Each centrifugal air compressor includes:

[0015] Intake valve;

[0016] The controller is communicatively connected to at least one centrifugal air compressor and is used to adjust the opening of the intake valve.

[0017] Fourthly, a readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the steps of the control method for the centrifugal air compressor described above.

[0018] In the aforementioned control method, device, system, and storage medium for centrifugal air compressors, during the production process of the centrifugal air compressor, the pressure head is calculated by real-time acquisition of the first-stage inlet temperature, first-stage inlet pressure, and final-stage exhaust pressure of the centrifugal air compressor. The pressure head is then used as the minimum / maximum load control value to control the operation of the air compressor. This avoids surge in the centrifugal air compressor and eliminates the need for a bypass valve to release air. As a result, the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0021] Figure 2 This is a schematic diagram of the anti-surge control curve of centrifugal air compression in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the control device for a centrifugal air compressor in one embodiment of the present invention. Detailed Implementation

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

[0024] Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or performed simultaneously. Moreover, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0025] Furthermore, the embodiments described herein are merely some, not all, of the embodiments of the invention. The components of the embodiments of the invention described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the 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 a feature subsequently declared, but does not exclude the addition of other features. It should also be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] The following is a detailed description of this case, in conjunction with the relevant accompanying drawings in the instruction manual.

[0028] In the embodiments described in this specification, surge is a unique phenomenon that occurs when a centrifugal air compressor operates under certain conditions. When the airflow entering the air compressor is insufficient to generate enough pressure, such that the pressure in the external system (external pipeline) exceeds the internal pressure of the air compressor, the check valve closes. At this time, the air compressor has no output, and air accumulates inside, causing the pressure to increase until it exceeds the pressure of the external system. At this point, the internal pressure of the air compressor forces open the check valve and discharges the gas. After the gas is discharged, because there is not enough air to maintain continuous output, the internal pressure of the air compressor drops, the check valve closes, and air accumulates again inside the air compressor until the accumulated pressure is sufficient, at which point it is discharged again. This cycle repeats, causing severe fluctuations in output pressure and motor load, frequent check valve operation, and a popping sound from the machine. This phenomenon is called surge.

[0029] Therefore, when the exhaust flow rate of a centrifugal air compressor suddenly decreases or reduces to a certain extent, it may cause airflow backflow, leading to surge in the unit. The severe vibrations caused by surge can severely damage the unit's bearings, seals, and other components.

[0030] Current surge control strategies for centrifugal air compressors include two approaches: one is to fix the intake valve position during compressor production, limiting its opening to a fixed degree to prevent further closure. This results in excess gas being diverted to the atmosphere via a bypass valve, leading to energy loss. The other approach uses current-limiting control to minimize load, essentially controlling the compressor's power input and thus its operating conditions. This is because motor current is related to the compressor's flow rate; as flow increases, the compressor needs to do more work to compress more gas, thus increasing the motor current; conversely, as flow decreases, the required power decreases, and the current decreases accordingly. By setting a lower current limit, the compressor operates under a relatively stable load, preventing excessively low flow rates and surge. However, this approach means that energy consumption cannot be effectively reduced during voltage fluctuations. Companies need to pay higher electricity bills to maintain compressor operation, increasing production costs. Furthermore, in an environment that advocates energy conservation and emission reduction, energy-inefficient operation is inconsistent with sustainable development requirements. Furthermore, when the voltage drops, according to the characteristics of the motor, the motor needs to output relatively stable power to maintain the operation of the air compressor. When the voltage decreases, the current will increase accordingly. However, a voltage drop may cause a decrease in the motor's output torque, leading to a tendency for the air compressor's impeller speed to decrease. Although the flow rate remains temporarily unchanged at this time, if the voltage continues to drop or the drop is significant, the impeller speed will decrease noticeably, resulting in a reduction in the compressor's flow rate. When the flow rate decreases below the surge flow rate, a surge phenomenon will occur.

[0031] To address the aforementioned issues, this application proposes a high-efficiency, energy-saving control method for centrifugal air compressors. This method utilizes a variable pressure head, where the calculated pressure head replaces the measured motor current value as the minimum load control value. In actual production, the compressor's operating conditions may change due to variations in intake conditions (such as temperature, pressure, and gas composition). The motor current is not closely correlated with these intake conditions, making it difficult to accurately reflect the compressor's surge risk based on changes in operating conditions. In contrast, the pressure head is directly related to intake conditions and can reflect the compressor's operating status in real time as conditions change, thus more effectively preventing surge.

[0032] Please see Figure 1 This specification provides a control method for a centrifugal air compressor, which specifically includes the following steps:

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

[0034] It is understood that the executing entity of this invention can be an LC-MS peak detection device, a terminal, or a server; the specific implementation is not limited here. This embodiment of the invention will be described using a server as an example.

[0035] In this step, upon receiving an operation request from the centrifugal air compressor (hereinafter referred to as the centrifugal air compressor), the centrifugal air compressor is started. During the operation of the centrifugal air compressor, the first-stage inlet air temperature, first-stage inlet air pressure, and final-stage exhaust pressure are collected in real time. The first-stage inlet air temperature refers to the temperature of the air entering the first-stage compression chamber of the centrifugal air compressor; the first-stage inlet air pressure refers to the pressure of the air entering the first-stage compression chamber; and the final-stage exhaust pressure refers to the pressure of the air discharged from the last stage compression chamber after multiple stages of compression.

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

[0037] In this step, head refers to the energy gain per unit weight of fluid in the compressor, reflecting the compressor's ability to compress air. In centrifugal air compressors, head represents the work done by the compressor to compress air from the intake state to the exhaust state. In actual production, the operating conditions of a centrifugal air compressor may change due to variations in intake conditions (such as temperature and pressure). Head is directly related to intake conditions and can reflect the compressor's working status in real time as operating conditions change. Using head as a control value, the load on the centrifugal air compressor can be precisely adjusted. Furthermore, by incorporating the final stage exhaust pressure into the head calculation, the final stage exhaust pressure directly reflects the final effect of the centrifugal air compressor's compression process. This allows the head calculation to more comprehensively reflect the actual operating state of the air compressor, thereby enabling head-based control and monitoring to more accurately determine whether the compressor is approaching the surge boundary. Therefore, by calculating the head using the initial stage intake temperature, initial stage intake pressure, and final stage exhaust pressure during the operation of the centrifugal air compressor, the operating status of the centrifugal compressor is monitored.

[0038] In one embodiment of this application, a specific head calculation scheme is provided. In S20, the head of the centrifugal air compressor is determined based on the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value. Specifically, this includes:

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

[0040] The formula for calculating the pressure head is as follows:

[0041]

[0042] In the formula, T H P1 is the first-stage intake air temperature, in degrees Fahrenheit; P2 is the last-stage exhaust pressure, in PSI (pounds per square inch); P1 is the first-stage intake pressure, in PSI (pounds per square inch).

[0043] In this embodiment, during multi-stage compression in a centrifugal air compressor, the intake temperatures of each stage differ. The highest-temperature stage (the first stage) has lower gas density and greater compressibility, requiring the compressor to overcome greater resistance to increase pressure, making it most susceptible to surge. Therefore, considering the conditions of the cooling water and air cooler, using this temperature to calculate the pressure head accurately simulates the compressor's operation under the worst conditions, making the calculated pressure head closer to the critical value at which surge actually occurs, thus more accurately defining the surge boundary. Furthermore, the first-stage intake pressure is the initial pressure condition of the centrifugal air compressor's compression process, directly affecting the compression ratio and pressure head requirements of subsequent stages. Considering the pressure drop in pipelines and intake filter air, accurately obtaining the first-stage intake pressure and using it for pressure head calculation and surge control avoids system performance degradation or equipment damage caused by intake pressure fluctuations. Finally, the final-stage discharge pressure directly reflects the air compressor's ability to overcome system resistance and compress gas to the required pressure; it is closely related to surge. When the final-stage discharge pressure is too high and the flow rate is insufficient, surge is easily triggered.

[0044] By introducing the highest-temperature first-stage intake temperature, first-stage intake pressure, and first-stage final-stage exhaust pressure calculation head through the above method, strong support is provided for the effective prevention and control of surge.

[0045] S30: Controls the operation of the centrifugal air compressor based on the pressure head.

[0046] In this step, by adjusting the operating parameters of the centrifugal air compressor, the pressure head is kept within a reasonable range. This avoids surge caused by excessively high or low pressure head. At the same time, based on the precise control of the pressure head, it can be ensured that the compressed air pressure and flow rate output by the centrifugal air compressor just meet the actual needs, without generating unnecessary excess gas, thereby achieving energy saving.

[0047] In one embodiment of this application, a specific control scheme for a centrifugal air compressor is provided. In S30, that is, based on the pressure head, the operation of the centrifugal air compressor is controlled, specifically including the following steps S31-S32:

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

[0049] S32: Based on the comparison results, adjust the opening degree of the air compressor's intake valve.

[0050] For steps S31-S32, there is a specific performance curve relationship between gas flow rate and pressure head in a centrifugal compressor. The first preset pressure head threshold corresponds to the minimum load state of the centrifugal air compressor and is the energy-saving trigger value to ensure stable operation and meet minimum process requirements. When the pressure head is close to or below this threshold, it indicates that although the air compressor can maintain stable operation, the intake air volume is excessive. The second preset pressure head threshold corresponds to the maximum load state of the centrifugal air compressor and is the upper limit of the pressure head that the air compressor can achieve within the safe operating range. When the pressure head is close to or above this threshold, it means that the air compressor is overloaded, and the air compressor needs to overcome greater resistance to increase the gas pressure. At a certain speed, if an excessively high pressure head is to be achieved, the gas flow rate will decrease accordingly. When the flow rate decreases to the surge flow rate, the airflow inside the compressor becomes unstable and prone to rotational separation, thus triggering surge. The opening of the intake valve of a centrifugal air compressor directly affects the gas flow rate entering the compressor. The intake valve opening is adjusted based on the calculated pressure head as the minimum / maximum load control value. By continuously fine-tuning the intake volume, the pressure head is stabilized within a suitable range, avoiding large fluctuations in pressure head and flow rate. This effectively suppresses the causes of surge and ensures that the air compressor always operates in a stable operating range (i.e., avoiding the surge line).

[0051] Optionally, the anti-surge control of the centrifugal air compressor uses head as the control value. Researchers can set the minimum load head setting value (i.e., the first preset head threshold) and the maximum load head setting 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 one embodiment of this application, a specific intake valve opening adjustment scheme is provided. In S32, that is, adjusting the opening of the intake valve of the centrifugal air compressor based on the comparison result, the specific steps include the following:

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

[0054] Based on the motor current value and the first preset current setting value, the opening of the intake valve is reduced through a proportional-integral-derivative control strategy until the pressure head is greater than the first preset pressure head threshold and less than the second preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

[0055] In this embodiment, the pressure head of the centrifugal air compressor is continuously monitored during production. When the pressure head is detected to be less than or equal to the first preset pressure head threshold corresponding to the minimum load state, intervention is required to save energy. Specifically, the real-time motor current value is acquired, and this current magnitude is directly related to the centrifugal air compressor load. Based on the current difference between the real-time current value and the first preset current setting value, an adjustment signal is generated through proportional (P)-integral (I)-derivative (D) calculation to drive the intake valve to reduce its opening, limiting the air intake flow of the air compressor, thereby gradually increasing the pressure head. This adjustment is repeated until the pressure head is within a safe range, i.e., satisfying the condition that the first preset pressure head threshold < real-time pressure head < second preset pressure head threshold.

[0056] In one embodiment of this application, a specific intake valve opening adjustment scheme is provided. In S32, that is, adjusting the opening of the intake valve of the centrifugal air compressor based on the comparison result, the following steps are also included:

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

[0058] Based on the motor current value and the second preset current setting value, the opening of the intake valve is increased through a proportional-integral-derivative control strategy until the pressure head is less than the second preset pressure head threshold and greater than the first preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

[0059] In this embodiment, during production, the pressure head of the centrifugal air compressor is continuously monitored. When the pressure head is detected to be greater than or equal to the second preset pressure head threshold corresponding to the maximum load state, the real-time motor current value of the air compressor is acquired. Based on the current deviation between the real-time motor current value and the second preset current setting value, an adjustment signal is generated through PID calculation to drive the intake valve to increase its opening and reduce the pressure head. This adjustment is repeated until the pressure head is within a safe range, i.e., satisfying the condition that the first preset pressure head threshold < real-time pressure head < second preset pressure head threshold.

[0060] By using the above method, the pressure head is used as the control value, and the pressure head is indirectly controlled through current feedback. Combined with the robustness of PID (proportional-integral-differential) control strategy, it is ensured that the air compressor can approach the surge zone without surging.

[0061] In practical application scenarios, such as Figure 2The diagram shows a schematic of the anti-surge control curve for a centrifugal air compressor. The horizontal axis represents flow rate, indicating the volumetric flow rate of the air compressor; the vertical axis represents pressure head. The natural surge point to the left of the curve is the minimum flow rate point; below this point, the air compressor enters the surge zone. The minimum load process / control setpoint (Minload_SP) to the right of the natural surge point is the anti-surge control line set by the R&D personnel to reserve a safety margin. In summer, T... H As the initial intake air temperature rises, the pressure head (Minload_CV) tends to increase. The PID controller automatically increases the intake valve opening to suppress the pressure head increase and prevent surge. In winter, T... H A decrease in the initial intake air temperature reduces the intake valve opening, saving energy. Furthermore, due to system pressure fluctuations or an increase in the set pressure, the exhaust pressure rises, causing the pressure head to tend to rise. The PID controller automatically increases the intake valve opening to suppress the pressure head rise and prevent surge; conversely, a decrease in exhaust pressure reduces the intake valve opening, saving energy.

[0062] As can be seen, in the above scheme, during the production process of centrifugal air compressor, the pressure head is calculated by real-time acquisition of the first-stage inlet temperature, first-stage inlet pressure, and last-stage exhaust pressure of the centrifugal air compressor. The pressure head is then used as the minimum / maximum load control value to control the operation of the air compressor. This avoids surge in the centrifugal air compressor and eliminates the need to use a bypass valve for venting. As a result, the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs.

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

[0064] The acquisition module 101 is used to acquire the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value of the centrifugal air compressor in response to the operation request of the centrifugal air compressor.

[0065] The determination module 102 is used to determine the head of the centrifugal air compressor based on the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value.

[0066] Control module 103 is used to control the operation of the centrifugal air compressor based on the pressure head.

[0067] In one embodiment, the determining module 102 is specifically used for:

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

[0069] The formula for calculating the pressure head is as follows:

[0070]

[0071] In one embodiment, the control module 103 is specifically used for:

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

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

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

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

[0076] Based on the motor current value and the first preset current setting value, the opening of the intake valve is reduced through a proportional-integral-derivative control strategy until the pressure head is greater than the first preset pressure head threshold and less than the second preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

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

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

[0079] Based on the motor current value and the second preset current setting value, the opening of the intake valve is increased through a proportional-integral-derivative control strategy until the pressure head is less than the second preset pressure head threshold and greater than the first preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

[0080] This invention provides a control device for a centrifugal air compressor. By collecting the first-stage inlet temperature, first-stage inlet pressure, and last-stage exhaust pressure of the centrifugal air compressor in real time, the pressure head is calculated and used as the minimum / maximum load control value to control the operation of the air compressor. This avoids surge in the centrifugal air compressor and eliminates the need to use a bypass valve for venting. This ensures that the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs.

[0081] Specific limitations regarding the control device for centrifugal air compressors can be found in the above description of the control methods for centrifugal air compressors, and will not be repeated here. Each module in the aforementioned control device for centrifugal air compressors can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in the electronic device, or stored in the memory of the electronic device as software, so that the processor can call and execute the corresponding operations of each module.

[0082] In one embodiment, a centrifugal air compressor control system is provided, applicable to the control method of the centrifugal air compressor described above, the system comprising:

[0083] At least one centrifugal air compressor;

[0084] Each centrifugal air compressor includes:

[0085] Intake valve;

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

[0087] This application provides a centrifugal air compressor control system. Specifically, the system includes one or more centrifugal air compressors, with an intake valve installed at the intake port of each centrifugal air compressor to control the airflow entering the compressor. A controller is communicatively connected to each centrifugal air compressor, and adjusts the opening of the intake valve to prevent compressor surge.

[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 inlet air temperature, first-stage inlet air pressure, and final-stage exhaust pressure of the air compressor. The head is used as the minimum / maximum load control value. The intake valve opening is adjusted through a proportional-integral-derivative control strategy to avoid surge of the centrifugal air compressor and eliminate the need to use a bypass valve for venting. This ensures that the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs.

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

[0090] The intake pipe connects to the intake valve.

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

[0092] The first temperature sensor is located on the intake pipe;

[0093] The second temperature sensor is located on the final stage compression assembly;

[0094] Pressure sensor, installed on the intake pipe;

[0095] Electric motor;

[0096] Current transformers are installed on the motor.

[0097] In this embodiment, for any centrifugal air compressor, the compressor includes an intake pipe connected to the intake valve and a multi-stage compression assembly (such as an impeller). The multi-stage compression assembly includes a first-stage compression assembly connected to the intake pipe and a final-stage compression assembly, which is the last stage in the multi-stage compression assembly. Further, the centrifugal air compressor also includes a temperature sensor and a pressure sensor. The first temperature sensor and pressure sensor are located on the intake pipe to monitor the first-stage intake air temperature and pressure entering the first-stage compression assembly in real time. The second temperature sensor is located at the outlet end of the final-stage compression assembly to monitor the final-stage exhaust temperature. Furthermore, the centrifugal air compressor also includes a motor to provide rotational power to moving parts such as the impeller, and a current transformer located on the motor to measure the motor's operating current. During the production process of centrifugal air compressors, the pressure head is calculated by collecting the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust pressure in real time. The pressure head is then used as the minimum / maximum load control value to control the operation of the air compressor. This avoids surge in the centrifugal air compressor and eliminates the need to use a bypass valve for venting. As a result, the centrifugal air compressor always operates under stable and efficient conditions, while reducing unnecessary energy loss, lowering energy consumption, and saving operating costs.

[0098] The centrifugal air compressor control system provided in this application automatically and precisely adjusts the opening of the air valve through a PID controller based on real-time changes in pressure head, so that the centrifugal air compressor is as close as possible to the surge zone without surge, thus preventing surge and saving energy.

[0099] In one embodiment, the centrifugal air compressor control system further includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0100] In response to the operation request of the centrifugal air compressor, the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust pressure of the centrifugal air compressor are obtained.

[0101] The head of the centrifugal air compressor is determined based on the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust air pressure.

[0102] The operation of the centrifugal air compressor is controlled based on the pressure head.

[0103] In one embodiment, a readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0104] In response to the operation request of the centrifugal air compressor, the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust pressure of the centrifugal air compressor are obtained.

[0105] The head of the centrifugal air compressor is determined based on the first-stage inlet air temperature, first-stage inlet air pressure, and last-stage exhaust air pressure.

[0106] The operation of the centrifugal air compressor is controlled based on the pressure head.

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

[0108] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory 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), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0109] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0110] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the 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, include: In response to the operation request of the centrifugal air compressor, the first-stage inlet temperature, first-stage inlet pressure and last-stage exhaust pressure of the centrifugal air compressor are acquired. The head of the centrifugal air compressor is determined based on the first-stage inlet temperature value, the first-stage inlet pressure value, and the last-stage exhaust pressure value. The centrifugal air compressor is controlled to operate based on the pressure head. The step of controlling the operation of the centrifugal air compressor based on the pressure head specifically includes: The pressure head is compared with a first preset pressure head threshold corresponding to the minimum load state and a second preset pressure head threshold corresponding to the maximum load state; Based on the comparison results, the opening degree of the intake valve of the centrifugal air compressor is adjusted.

2. The method according to claim 1, characterized in that, The step of determining the head of the centrifugal air compressor based on the first-stage inlet air temperature, the first-stage inlet air pressure, and the last-stage exhaust pressure specifically includes: The first-stage intake temperature value, the first-stage intake pressure value, and the last-stage exhaust pressure value are input into the head calculation formula to calculate the head of the centrifugal air compressor. The formula for calculating the pressure head is as follows:

3. The method according to claim 1, characterized in that, The step of adjusting the opening degree of the intake valve of the centrifugal air compressor based on the comparison results specifically includes: When the pressure head is less than or equal to the first preset pressure head threshold, the motor current value of the centrifugal air compressor is obtained; Based on the motor current value and the first preset current setting value, the opening of the intake valve is reduced through a proportional-integral-derivative control strategy until the pressure head is greater than the first preset pressure head threshold and less than the second preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

4. The method according to claim 1, characterized in that, The step of adjusting the opening of the intake valve of the centrifugal air compressor based on the comparison results further includes: When the pressure head is greater than or equal to the second preset pressure head threshold, the motor current value of the centrifugal air compressor is obtained; Based on the motor current value and the second preset current setting value, the opening of the intake valve is increased through a proportional-integral-derivative control strategy until the pressure head is less than the second preset pressure head threshold and greater than the first preset pressure head threshold, at which point the adjustment of the intake valve opening is stopped.

5. A control device for a centrifugal air compressor, characterized in that, include: The acquisition module is used to acquire the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value of the centrifugal air compressor in response to the operation request of the centrifugal air compressor. The determination module is used to determine the head of the centrifugal air compressor based on the first-stage inlet air temperature value, the first-stage inlet air pressure value, and the last-stage exhaust pressure value. A control module is used to control the operation of the centrifugal air compressor based on the pressure head; The control module is specifically used for: Compare the pressure head with the first preset pressure head threshold corresponding to the minimum load state and the second preset pressure head threshold corresponding to the maximum load state; Based on the comparison results, adjust the opening of the intake valve of the centrifugal air compressor.

6. A centrifugal air compressor control system, characterized in that, A control method applicable to a centrifugal air compressor according to any one of claims 1 to 4, the system comprising: At least one centrifugal air compressor; Each centrifugal air compressor includes: Intake valve; A controller, communicatively connected to the at least one centrifugal air compressor, is used to adjust the opening of the intake valve.

7. The centrifugal air compressor control system according to claim 6, characterized in that, Each centrifugal air compressor also includes: An intake pipe is connected to the intake valve; A multi-stage compression component, wherein the multi-stage compression component includes a first-stage compression component and a last-stage compression component; A first temperature sensor is installed on the air intake pipe; A second temperature sensor is disposed on the final stage compression assembly; A pressure sensor is installed on the intake pipe; Electric motor; A current transformer is installed on the motor.

8. The centrifugal air compressor control system according to claim 6, characterized in that, Also includes: A memory that stores programs or instructions; A processor, connected to the memory, implements the control method for a centrifugal air compressor as described in any one of claims 1 to 4 when executing the program or instructions.

9. 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 for the centrifugal air compressor as described in any one of claims 1 to 4.

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