Control method, control device, processor and compressor unit for a compressor unit

Abstract

This invention provides a control method, control device, processor, and compressor unit for a compressor unit, belonging to the field of compressor technology. The compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system provides sealing gas to the compressor body and includes a regulating valve. The control method for the compressor unit includes: acquiring the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system; determining the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure; determining a target opening adjustment strategy for the regulating valve based on the internal pressure and operating condition information; and adjusting the opening of the regulating valve according to the target opening adjustment strategy when the current flow rate is not equal to the target flow rate, so as to control the current flow rate at the target flow rate. This invention can improve the stability of sealing gas flow control.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically to a control method, control device, processor, and compressor unit for compressor units. Background Technology

[0002] In existing technologies, during the operation of compressor units, the flow rate of sealing gas is typically controlled by automatically adjusting the valve opening using PID control. However, during certain operating phases of the compressor unit, such as the purging phase, the pressure difference between the compressor's inlet and outlet has not yet been established, making stable control of the sealing gas flow rate impossible using PID control. Therefore, existing technologies suffer from unstable sealing gas flow rate control. Summary of the Invention

[0003] The purpose of this invention is to provide a control method, control device, processor, and compressor unit for compressor units, so as to solve the problem of unstable control of sealing gas flow in the prior art.

[0004] To achieve the above objectives, a first aspect of the present invention provides a control method for a compressor unit, the compressor unit including a compressor body and a dry gas sealing system, the dry gas sealing system being used to supply sealing gas to the compressor body, the dry gas sealing system including a regulating valve, and the control method including:

[0005] Obtain the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system;

[0006] Determine the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure.

[0007] Determine the target opening adjustment strategy for the control valve based on internal pressure and operating condition information;

[0008] When the current flow rate is not equal to the target flow rate, the opening of the regulating valve is adjusted according to the target opening adjustment strategy to control the current flow rate at the target flow rate.

[0009] In this embodiment of the invention, determining the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure includes: determining the pressure range where the internal pressure is located; and determining the target flow rate as a preset target flow rate corresponding to the pressure range.

[0010] In this embodiment of the invention, determining the target opening adjustment strategy for the regulating valve based on internal pressure and operating condition information includes: determining the pressure range where the internal pressure is located; determining the corresponding adjustment time interval and adjustment opening ratio based on a preset correspondence relationship, wherein the preset correspondence relationship is the relationship between the pressure range, operating condition information, adjustment time interval, and adjustment opening ratio; and determining the target opening adjustment strategy as increasing the adjustment opening ratio at each adjustment time interval.

[0011] In this embodiment of the invention, the operating condition information includes purging condition or pressurizing condition, and the adjustment opening ratio of each pressure range corresponding to the purging condition or pressurizing condition is positively correlated with the pressure value of each pressure range.

[0012] In this embodiment of the invention, after adjusting the opening of the regulating valve according to the target opening adjustment strategy, the method further includes: acquiring the outlet pressure and inlet pressure of the compressor body; determining whether the dry gas sealing system is in a preset stable state based on the outlet pressure, inlet pressure, and current flow rate, wherein the preset stable state is a state in which the difference between the outlet pressure and the inlet pressure is greater than a preset pressure difference and the current flow rate is greater than or equal to a preset steady-state flow rate; and performing PID control on the flow rate of the sealing gas in the dry gas sealing system when the dry gas sealing system is in the preset stable state and the duration of maintaining the preset stable state reaches a preset duration.

[0013] In this embodiment of the invention, the control method further includes: acquiring the current temperature of the sealing gas in the dry gas sealing system; determining a target temperature control strategy based on the current temperature; and controlling the temperature of the sealing gas in the dry gas sealing system according to the target temperature control strategy.

[0014] In this embodiment of the invention, the dry gas sealing system further includes a heating device; determining a target temperature control strategy based on the current temperature includes: when the current temperature is in a low temperature range, controlling the power of the heating device to a preset power; when the current temperature is in a non-low temperature range, performing PID control on the power of the heating device based on the preset target temperature and the preset PID coefficient to achieve temperature control of the sealing gas.

[0015] In this embodiment of the invention, there are multiple low-temperature zones, and the preset power corresponding to each low-temperature zone is negatively correlated with the temperature value of each low-temperature zone.

[0016] In this embodiment of the invention, there are multiple non-low temperature ranges; the power of the heating device is controlled by PID according to the preset target temperature and the preset PID coefficient, including: the power of the heating device is controlled by PID according to the preset target temperature corresponding to each non-low temperature range and the preset PID coefficient corresponding to each non-low temperature range.

[0017] In this embodiment of the invention, the air supply port connecting the dry gas sealing system to the outside is equipped with a booster skid, which includes multiple booster pumps. The control method further includes: obtaining the running time of each booster pump; updating the running priority of each booster pump according to the running time, wherein the running priority is negatively correlated with the running time; and controlling the operation of each booster pump based on the running priority.

[0018] In this embodiment of the invention, there are multiple compressor units, and multiple dry gas sealing systems are connected to the outside world through a single booster skid to supply gas. The control method further includes: determining that there is a target compressor unit among the multiple compressor units, wherein the target compressor unit is a compressor unit in a stable flow state of sealing gas; controlling the target compressor unit to stop supplying gas through the booster skid, and controlling any compressor unit among the multiple compressor units other than the target compressor unit to supply gas through the booster skid.

[0019] A second aspect of the present invention provides a processor configured to execute the control method for a compressor unit as described above.

[0020] A third aspect of the present invention provides a control device for a compressor unit, the compressor unit including a compressor body and a dry gas sealing system, the dry gas sealing system being used to supply sealing gas to the compressor body, the dry gas sealing system including a regulating valve, the control device including: a pressure detection device for detecting the internal pressure of the compressor body; a flow detection device for detecting the current flow rate of the sealing gas in the dry gas sealing system; and a processor according to the above.

[0021] A fourth aspect of the present invention provides a compressor unit, comprising: a compressor body; a dry gas sealing system for supplying sealing gas to the compressor body, including a regulating valve; and a control device for the compressor unit according to the above.

[0022] The aforementioned control method for compressor units acquires the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system. Based on the internal pressure, it determines the target flow rate of the sealing gas in the dry gas sealing system. Then, based on the internal pressure and operating condition information, it determines the target opening adjustment strategy for the regulating valve. Thus, when the current flow rate does not equal the target flow rate, the opening of the regulating valve is adjusted according to the target opening adjustment strategy to control the current flow rate at the target flow rate. This technical solution considers the flow control of the sealing gas under different operating conditions of the compressor unit. The target flow rate of the sealing gas changes with the internal pressure of the compressor body, and the target opening adjustment strategy of the regulating valve changes with the operating conditions of the compressor unit and the internal pressure of the compressor body. When there is a deviation between the current flow rate and the target flow rate, adjusting the opening of the regulating valve based on the target opening adjustment strategy can improve the stability of the sealing gas flow control, ensure the safe and stable operation of the compressor unit, provide a stable and accurate sealing gas flow rate for the compressor unit under different operating conditions, and eliminate the need for manual judgment, reducing the probability of human error and prediction errors.

[0023] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 The schematic diagram illustrates a flow chart of a control method for a compressor unit according to an embodiment of the present invention;

[0026] Figure 2 The schematic diagram illustrates a structural block diagram of a control device for a compressor unit according to an embodiment of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] Figure 1 The diagram illustrates a flow chart of a control method for a compressor unit according to an embodiment of the present invention. Figure 1 As shown, in this embodiment of the invention, a control method for a compressor unit is provided. The compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system is used to provide sealing gas to the compressor body. The dry gas sealing system includes a regulating valve. Taking the application of this control method to a processor as an example, the control method may include the following steps:

[0031] Step S102: Obtain the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system.

[0032] Step S104: Determine the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure.

[0033] Step S106: Determine the target opening adjustment strategy for the regulating valve based on the internal pressure and operating condition information.

[0034] Step S108: When the current flow rate is not equal to the target flow rate, adjust the opening of the regulating valve according to the target opening adjustment strategy to control the current flow rate at the target flow rate.

[0035] It can be understood that a compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system is connected to the compressor body and provides clean, dry sealing gas to the compressor body, which can then compress process gases and other gases. The dry gas sealing system includes a regulating valve, which can be installed on the inlet passage of the dry gas sealing system to regulate the flow rate of the sealing gas entering the compressor body. The internal pressure of the compressor body is the cylinder pressure, which can be detected by pressure detection equipment. The compressor unit's operating condition information refers to its running status information, which may include purging, pressurizing, and venting conditions. The current flow rate of the sealing gas is the flow rate of the sealing gas in the dry gas sealing system at the current moment, which can be detected by flow detection equipment. The target flow rate is the desired sealing gas flow rate. The target opening adjustment strategy is the method for adjusting the opening of the regulating valve based on the internal pressure of the compressor body and the compressor unit's operating condition information.

[0036] Specifically, the processor can acquire the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system. The internal pressure of the compressor body can be obtained through pressure detection equipment, and the current flow rate of the sealing gas in the dry gas sealing system can be obtained through flow detection equipment. Further, the processor can determine the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure of the compressor body. For example, it can determine the target flow rate of the sealing gas in the dry gas sealing system based on the current internal pressure of the compressor body, using a pre-stored correspondence between the internal pressure of the compressor body and the target flow rate of the sealing gas. This correspondence can be in the form of an algorithm or a table. Furthermore, the processor can determine the target opening adjustment strategy for the regulating valve based on the internal pressure and operating condition information. For example, it can determine the target opening adjustment strategy for the corresponding regulating valve based on the current internal pressure and operating condition information, using a pre-stored correspondence between the internal pressure, operating condition information, and opening adjustment strategy. This correspondence can be in the form of a table. After determining the target flow rate, the processor can compare the target flow rate with the current flow rate. If the current flow rate is not equal to the target flow rate, the processor can adjust the opening of the control valve according to the target opening adjustment strategy to control the current flow rate at or near the target flow rate. Furthermore, it is understandable that a certain deviation is permissible between the current flow rate and the target flow rate. That is, if the deviation between the current flow rate and the target flow rate is within the allowable error range, the processor may not need to adjust the opening of the control valve according to the target opening adjustment strategy to avoid repeated adjustments that could reduce the sensitivity of the control valve.

[0037] The aforementioned control method for compressor units acquires the internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system. Based on the internal pressure, it determines the target flow rate of the sealing gas in the dry gas sealing system. Then, based on the internal pressure and operating condition information, it determines the target opening adjustment strategy for the regulating valve. Thus, when the current flow rate does not equal the target flow rate, the opening of the regulating valve is adjusted according to the target opening adjustment strategy to control the current flow rate at the target flow rate. This technical solution considers the flow control of the sealing gas under different operating conditions of the compressor unit. The target flow rate of the sealing gas changes with the internal pressure of the compressor body, and the target opening adjustment strategy of the regulating valve changes with the operating conditions of the compressor unit and the internal pressure of the compressor body. When there is a deviation between the current flow rate and the target flow rate, adjusting the opening of the regulating valve based on the target opening adjustment strategy can improve the stability of the sealing gas flow control, ensure the safe and stable operation of the compressor unit, provide a stable and accurate sealing gas flow rate for the compressor unit under different operating conditions, and eliminate the need for manual judgment, reducing the probability of human error and prediction errors.

[0038] In one embodiment, determining the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure includes: determining the pressure range where the internal pressure is located; and determining the target flow rate as a preset target flow rate corresponding to the pressure range.

[0039] It is understandable that there are multiple pressure ranges, which can be predetermined. The preset target flow rate is the pre-set flow rate of the sealing gas. Different pressure ranges correspond to different preset target flow rates; that is, the correspondence between pressure ranges and preset target flow rates can be preset and stored.

[0040] Specifically, after acquiring the internal pressure of the compressor body, the processor can determine the pressure range within which that internal pressure lies, and determine the target flow rate as a preset target flow rate corresponding to that pressure range. Furthermore, the preset target flow rate corresponding to the pressure range can be determined based on a pre-stored correspondence between pressure ranges and preset target flow rates. For example, when the pressure range is 1 MPa to 5 MPa, the target flow rate corresponding to that pressure range can be 350 Nm³. 3 / h; When the pressure range is 0MPa to 1MPa, the target flow rate corresponding to this pressure range can be 250Nm³. 3 / h; When the pressure range is 5MPa to 10MPa, the target flow rate corresponding to this pressure range can be 420Nm. 3 / h.

[0041] In this embodiment of the application, by determining the pressure range in which the internal pressure of the compressor body is located, and determining the target flow rate as the preset target flow rate corresponding to the pressure range, that is, by segmenting the internal pressure of the compressor body, segmented control of the sealing airflow is achieved, which is to achieve step control of the sealing airflow.

[0042] In one embodiment, determining the target opening adjustment strategy for the regulating valve based on internal pressure and operating condition information includes: determining the pressure range in which the internal pressure is located; determining the corresponding adjustment time interval and adjustment opening ratio based on a preset correspondence relationship, wherein the preset correspondence relationship is the relationship between the pressure range, operating condition information, adjustment time interval, and adjustment opening ratio; and determining the target opening adjustment strategy as increasing the adjustment opening ratio at each adjustment time interval.

[0043] It can be understood that the preset correspondence is the relationship between the four factors that are predetermined and stored: pressure range, operating condition information, adjustment time interval, and adjustment opening ratio. In other words, different pressure ranges and operating condition information can correspond to different adjustment time intervals and adjustment opening ratios. The adjustment time interval is the interval between adjustments to the opening of the control valve, such as 5 seconds or 10 seconds, and the adjustment opening ratio is the adjustment amount of the control valve opening, such as 5% or 3%.

[0044] Specifically, the processor can first determine the pressure range of the compressor body's internal pressure, and based on a preset correspondence, determine the corresponding adjustment time interval and adjustment opening ratio according to the pressure range and operating condition information. The target opening adjustment strategy is to increase the adjustment opening ratio every adjustment time interval. For example, when the pressure range is 1MPa to 5MPa and the operating condition is venting, the adjustment time interval can be 3 seconds and the adjustment opening ratio can be 1%; when the pressure range is 1MPa to 5MPa and the operating condition is purging, the adjustment time interval can be 10 seconds and the adjustment opening ratio can be 3%; when the pressure range is 0MPa to 1MPa and the operating condition is venting, the adjustment time interval can be 3 seconds and the adjustment opening ratio can be 2.5%; and when the pressure range is 0MPa to 1MPa and the operating condition is purging, the adjustment time interval can be 10 seconds and the adjustment opening ratio can be 1.5%.

[0045] In this embodiment, by pre-setting the correspondence between pressure range, operating condition information, adjustment time interval, and adjustment opening ratio, the adjustment time interval and adjustment opening ratio of the proportional valve change with the changes in pressure range and operating condition, which can more accurately achieve step control of sealing airflow and thus achieve stable control of sealing airflow.

[0046] In one embodiment, the operating condition information includes purging operating condition or pressurizing operating condition, and the adjustment opening ratio of each pressure range corresponding to the purging operating condition or pressurizing operating condition is positively correlated with the pressure value of each pressure range.

[0047] It is understandable that when the compressor unit is operating in purging or pressurizing mode, the regulating opening ratio corresponding to the pressure range is positively correlated with the pressure value of the pressure range. That is, the higher the pressure value within the pressure range, the larger the regulating opening ratio of the regulating valve for each adjustment time interval. For example, if the compressor unit is operating in purging or pressurizing mode, the regulating opening ratio can be 1.5% when the pressure range is 0MPa to 1MPa, 3% when the pressure range is 1MPa to 5MPa, and 5% when the pressure range is 5MPa to 10MPa. In other words, when the compressor unit is operating in purging or pressurizing mode, the regulating opening ratio increases with the increase of the pressure range.

[0048] In this embodiment, the adjustment opening ratio of each pressure range corresponding to the purging or pressurizing condition is positively correlated with the pressure value of each pressure range, which can accelerate the flow control process of the sealing gas under the purging or pressurizing condition and improve the operating efficiency of the compressor unit.

[0049] In one embodiment, after adjusting the opening of the regulating valve according to the target opening adjustment strategy, the method further includes: acquiring the outlet pressure and inlet pressure of the compressor body; determining whether the dry gas sealing system is in a preset stable state based on the outlet pressure, inlet pressure, and current flow rate; and performing PID control on the flow rate of the sealing gas in the dry gas sealing system when the dry gas sealing system is in a preset stable state and the duration of maintaining the preset stable state reaches a preset duration, wherein the preset stable state is a state in which the difference between the outlet pressure and the inlet pressure is greater than a preset pressure difference and the current flow rate is greater than or equal to a preset steady-state flow rate.

[0050] It can be understood that the preset steady state is a state where the difference between the compressor's outlet pressure and inlet pressure is greater than a preset pressure difference and the current flow rate is greater than or equal to the preset steady-state flow rate. The preset pressure difference is a pre-set pressure difference value, such as 0.25 MPa, and the preset steady-state flow rate is a pre-set sealing gas flow rate value indicating that the dry gas sealing system has initially stabilized, such as 320 Nm³. 3 / h. The preset duration is the pre-set time length, such as 10 seconds or 15 seconds.

[0051] Specifically, the processor can obtain the outlet and inlet pressures of the compressor body through a pressure detection device, and determine whether the dry gas sealing system is in a preset stable state based on the outlet pressure, inlet pressure, and current flow rate. Specifically, it determines the difference between the outlet and inlet pressures and compares this difference with a preset pressure difference (e.g., 0.25 MPa), and compares the current flow rate with a preset steady-state flow rate (e.g., 320 Nm³). 3 When the difference between the outlet pressure and the inlet pressure is greater than the preset pressure difference and the current flow rate is greater than or equal to the preset steady-state flow rate, it indicates that the dry gas sealing system is in a preset stable state. The duration for which the several gas sealing systems maintain this preset stable state reaches the preset duration (e.g., 10 seconds), at which point the inlet and outlet pressure difference of the compressor body has been established and the flow rate of the sealing gas is in a stable state. At this time, the processor can perform PID control on the flow rate of the sealing gas in the dry gas sealing system.

[0052] In this embodiment, by first performing step control on the flow rate of the sealing gas, and then performing PID control on the flow rate of the sealing gas after reaching a preset stable state, stable control of the sealing gas flow rate can be further achieved.

[0053] Understandably, when the flow rate of the sealing gas in the dry gas sealing system is unstable, the temperature of the sealing gas in the dry gas sealing system will also be affected. In one embodiment, the control method for the compressor unit further includes: acquiring the current temperature of the sealing gas in the dry gas sealing system; determining a target temperature control strategy based on the current temperature; and controlling the temperature of the sealing gas in the dry gas sealing system according to the target temperature control strategy.

[0054] It can be understood that the target temperature control strategy is a temperature control strategy for the sealing gas in the dry gas sealing system determined based on the temperature of the sealing gas in the dry gas sealing system. In other words, the temperature control strategy for the sealing gas will change with the change of the temperature of the sealing gas.

[0055] Specifically, the processor can obtain the current temperature of the sealing gas in the dry gas sealing system, determine the target temperature control strategy corresponding to the current temperature based on the current temperature, and then control the temperature of the sealing gas in the dry gas sealing system according to the target temperature control strategy.

[0056] In this embodiment of the application, the temperature of the sealing gas is also controlled during the process of controlling the flow rate of the sealing gas, which can improve the operating efficiency of the compressor unit and is conducive to the stable and safe operation of the dry gas sealing system.

[0057] In one embodiment, the dry gas sealing system further includes a heating device; determining a target temperature control strategy based on the current temperature includes: when the current temperature is in a low-temperature range, controlling the power of the heating device to a preset power; when the current temperature is in a non-low-temperature range, performing PID control on the power of the heating device based on the preset target temperature and a preset PID coefficient to achieve temperature control of the sealing gas.

[0058] It can be understood that the low-temperature range is a predetermined low-temperature range, such as 0℃ to 35℃. The non-low-temperature range is the temperature range outside the low-temperature range, which can be understood as the high-temperature range. The heating device is a device used to heat the sealing gas, such as a heater. The preset power is the preset power of the heating device. Furthermore, the processor can output different proportional values ​​to change the power of the heating device. For example, if the processor outputs 100%, it indicates that the power of the heating device is 100% of its rated power; if the processor outputs 50%, it indicates that the power of the heating device is 50% of its rated power. The preset target temperature is the preset desired temperature of the sealing gas, and the preset PID coefficient is the preset coefficient of PID control. The preset PID coefficient may include proportional coefficient and / or integral coefficient and / or derivative coefficient.

[0059] Specifically, the processor can determine whether the current temperature of the sealing gas in the dry gas sealing system is in the low temperature range or not. If the current temperature is in the low temperature range, the processor can directly control the power of the heating device to the preset power, that is, set the power of the heating device to the preset power. If the current temperature is in the non-low temperature range, the processor can perform PID control on the power of the heating device according to the preset target temperature and the preset PID coefficient to achieve temperature control of the sealing gas in the dry gas sealing system.

[0060] In this embodiment, the temperature control strategies for the sealing gas in the low-temperature and high-temperature stages are different. In the low-temperature stage, step control is used to directly control the power of the heating device to a preset power. In the high-temperature stage, PID control is used to control the power of the heating device to achieve control of the sealing gas temperature. Step control in the low-temperature stage can achieve stable and efficient control of the sealing gas temperature, while PID control in the high-temperature stage can achieve fine control of the sealing gas temperature, thereby extending the service life of the dry gas sealing system.

[0061] In one embodiment, there are multiple low-temperature zones, and the preset power corresponding to each low-temperature zone is negatively correlated with the temperature value of each low-temperature zone.

[0062] It is understandable that the smaller the temperature value in the low-temperature range, the larger the preset power corresponding to the low-temperature range. For example, when the low-temperature range is 0℃ to 25℃, the preset power can be 100% of the rated power, and when the low-temperature range is 25℃ to 35℃, the preset power can be 50% of the rated power.

[0063] In one embodiment, there are multiple non-low temperature zones; PID control of the power of the heating device is performed according to a preset target temperature and a preset PID coefficient, including: PID control of the power of the heating device according to the preset target temperature corresponding to each non-low temperature zone and the preset PID coefficient corresponding to each non-low temperature zone.

[0064] It is understandable that when there are multiple non-low temperature ranges, a preset target temperature and preset PID coefficient can be set for each non-low temperature range.

[0065] Specifically, if there are multiple non-low temperature zones, the processor can perform PID control on the power of the heating device based on the preset target temperature and the preset PID coefficient corresponding to each non-low temperature zone, so as to achieve temperature control of the sealing gas in the dry gas sealing system.

[0066] In one embodiment, the air supply port connecting the dry gas sealing system to the outside is equipped with a booster skid, which includes multiple booster pumps. The control method further includes: acquiring the running time of each booster pump; updating the operating priority of each booster pump according to the running time, wherein the operating priority is negatively correlated with the running time; and controlling the operation of each booster pump based on the operating priority.

[0067] It is understandable that the function of the booster skid is to increase pressure. The running time is the length of time the booster pump has been running. The running priority is the order in which the booster pumps run. Understandably, the longer the running time of a booster pump, the lower its running priority, and the shorter the running time of a booster pump, the higher its running priority.

[0068] Specifically, the processor can obtain the runtime of each booster pump and update the running priority of each booster pump according to the runtime, thereby controlling the operation of each booster pump based on the running priority, so as to achieve the effect of balancing the running time and improving the reliability of the equipment.

[0069] In one embodiment, there are multiple compressor units, and multiple dry gas sealing systems are connected to the outside world through a single booster skid to supply gas. The control method further includes: determining that there is a target compressor unit among the multiple compressor units, wherein the target compressor unit is a compressor unit in a stable flow state of sealing gas; controlling the target compressor unit to stop supplying gas through the booster skid, and controlling any compressor unit among the multiple compressor units other than the target compressor unit to supply gas through the booster skid.

[0070] It can be understood that a stable sealing gas flow state is a state in which the sealing gas within the compressor unit can flow in the forward direction. That is, the difference between the outlet pressure and the inlet pressure of the compressor body reaches a certain preset value, indicating that the inlet and outlet pressure difference of the compressor body is established. The target compressor unit is the compressor unit in a stable sealing gas flow state.

[0071] Specifically, when there are multiple compressor units, there are also multiple dry gas sealing systems. Multiple dry gas sealing systems share a single pressurization skid. If there is a target compressor unit among the multiple compressor units that is in a stable sealing gas flow state, the processor can control the target compressor unit to stop supplying gas through the pressurization skid, and control any compressor unit among the multiple compressor units other than the target compressor unit to supply gas through the pressurization skid.

[0072] In existing technologies, in compressor stations where multiple electrically driven centrifugal compressor units operate in parallel, these units often share a single dry gas sealing booster skid, which is typically equipped with two or three booster pumps. After the compressor unit is running stably, it can provide sealing gas from its own high-pressure outlet process gas or provide sealing gas to other compressor units.

[0073] If no compressor unit provides sealing gas, during the purging, pressurizing, and venting phases of operation when the inlet and outlet pressure differentials are not established, the dry gas sealing booster pump must provide external sealing gas. Since the sealing gas supply from the booster skid can only meet the needs of one compressor unit at a time, the start-up or shutdown of the compressor unit must consider whether the booster pump is being used by other compressor units. Only if it is not being used can the start-up and shutdown operations of this compressor unit be performed.

[0074] Currently, during the start-up and shutdown of the compressor unit, the supply of sealing gas requires extensive manual judgment, leading to frequent misoperations and inaccurate predictions. Furthermore, while the flow rate of the sealing gas is controlled by conventional PID automatic adjustment of the pneumatic diaphragm valve opening, during purging, pressurization, and venting phases, the inlet and outlet pressure differential has not yet been established, making stable PID control unsustainable. Additionally, the unstable sealing gas flow rate can cause frequent overheating of the sealing gas process pipeline heaters, requiring manual intervention from on-site personnel and posing a risk of dry gas seal damage.

[0075] To reduce the uncertainty of the safe operation of the dry gas seal system caused by untimely or misjudgment of manual operation during the start-up and shutdown of compressor units, it is necessary to study an adaptive dry gas seal control technology under operating conditions such as unit purging, pressurization, and venting. This technology can improve the automation level of the existing unit control system and meet the needs of the pipeline control center for remote start-up and shutdown of units, and has a very broad application prospect.

[0076] Specifically, in one particular embodiment, the control method for the compressor unit may include the following:

[0077] (1) Automatic priority determination function for booster pump:

[0078] The booster skid is equipped with 2 or 3 booster pumps. These pumps automatically switch operating priorities based on runtime, balancing operating time and improving equipment reliability. When the booster skid is not occupied, the booster pumps can automatically switch priorities.

[0079] (2) Shared control function for booster skid:

[0080] When the compressor unit starts up automatically or stops automatically, if the dry gas sealing inlet valve and the anti-surge valve are not fully closed, meaning that the sealing gas flow rate in the compressor unit cannot be guaranteed to flow in the positive direction, then the compressor unit will occupy the booster skid. If the booster skid is occupied by a compressor unit, the start-up or shutdown of other compressor units will not be allowed.

[0081] (3) Seal flow control function during purging and pressurization stages:

[0082] During the purging and pressurizing phases of the compressor unit, the program automatically executes the sealing flow control function for these phases. The compressor cylinder pressure is calibrated in three stages, with different setpoints and different MT adjustment parameters assigned to the dry gas sealing flow controller within each pressure range (where M is the adjustment opening ratio and T is the adjustment time interval). By controlling the parameters as they change with increasing cylinder pressure, stable control of the sealing gas flow rate can be achieved. After repeated on-site testing and verification, the following parameter control was ultimately determined:

[0083] When the compressor cylinder pressure is ≤1MPa, the set value is 250Nm. 3 / h, M is 1.5%, T is 10s;

[0084] When the compressor cylinder pressure is between 1 MPa and 5 MPa, the set value is 350 Nm. 3 / h, M is 3%, T is 10s;

[0085] When the compressor cylinder pressure is >5MPa, the set value is 420Nm. 3 / h, M is 5%, T is 5S.

[0086] (4) Automatic air release control function:

[0087] After the compressor unit triggers a normal or pressure-maintaining shutdown command, a five-step procedure for venting is set:

[0088] The program controls the opening of the dry gas seal inlet valve; after the compressor unit stops running, if the sealing gas flow is insufficient or the difference between the outlet pressure and the cylinder pressure is less than the set value, the program controls the closing of the loading valve; the program controls the opening of the venting valve and starts the venting stage sealing flow control; after the compressor cylinder pressure is completely released, the dry gas seal inlet valve is closed; after the dry gas seal inlet valve is closed, the shutdown command is automatically reset.

[0089] (5) Sealing flow control function during venting phase:

[0090] When the compressor unit triggers a normal or pressure-holding shutdown command, it automatically executes the sequential control process. The program controls the closing of the loading valve and the opening of the venting valve. Then, it automatically executes the sealing flow control during the venting phase. The dry gas sealing flow controller outputs a certain initial opening degree, and the compressor cylinder pressure is calibrated in three stages. In each pressure range, different set values ​​and different MT adjustment parameters are given to the dry gas sealing flow controller (where the adjustment parameter M is the adjustment opening ratio and the adjustment parameter T is the adjustment time interval). By controlling the parameters as the cylinder pressure decreases, stable control of the sealing gas flow can be achieved.

[0091] After repeated on-site testing and verification, the following parameter control was finally determined:

[0092] When the compressor cylinder pressure is >5MPa, the set value is 420Nm. 3 / h, M is 2%, T is 3S;

[0093] When the compressor cylinder pressure is between 1 MPa and 5 MPa, the set value is 350 Nm. 3 / h, M is 1%, T is 3S;

[0094] When the compressor cylinder pressure is ≤1MPa, the set value is 250Nm. 3 / h, M is 2.5%, T is 3S.

[0095] In addition, if (compressor outlet pressure - compressor inlet pressure) > 0.25 MPa and the sealing gas flow rate is ≥ 320 Nm3 / h, then after a 10-second delay, the step control can be switched to PID control.

[0096] (6) Dry gas seal heater temperature segmentation control function:

[0097] After achieving stable control of the sealing gas flow rate using the above method, the temperature of the dry gas sealing heating gas is controlled in segments. Step control is used in the low-temperature segment, while different PID parameters are used within each segment of the high-temperature segment to achieve stable control of the temperature heater. After repeated on-site testing and verification, the following parameter control was finally determined:

[0098] When the sealing gas temperature is <25℃, the controller output is 100%, using step control;

[0099] When the sealing gas temperature is between 25℃ and 35℃, the controller output is 50%, using step control.

[0100] When the sealing gas temperature is greater than 35℃, the controller outputs 25%, switching from step control to PID control.

[0101] The sealing gas temperature is ≥65℃, and the controller output is ≥30%, with the PID setting value at 5℃.

[0102] The sealing gas temperature is ≥65℃, and the controller output is 20% < 30% with the PID setpoint being 10℃.

[0103] The sealing gas temperature is ≥65℃, while the controller output is ≤20%, and the PID setting value is 25℃.

[0104] When the sealing gas temperature is 55℃ < 65℃, the PID setting value is 45℃; when the sealing gas temperature is ≤ 55℃, the PID setting value is 50℃.

[0105] When the sealing gas temperature is between 35℃ and 55℃, the D value of the PID is 15; when the sealing gas temperature is greater than 55℃, the D value of the PID is 5.

[0106] When the sealing gas temperature is ≤25℃, the I value of the PID is 30; when the sealing gas temperature is 25℃ < 35℃, the I value of the PID is 40; when the sealing gas temperature is 35℃ ≤ 55℃, the I value of the PID is 60.

[0107] When the sealing gas temperature is ≥60℃, the P value of the PID is 800; when the sealing gas temperature is <60℃, the P value of the PID is 200.

[0108] In summary, the technical solution provided by the embodiments of the present invention ensures the safe and stable operation of the dry gas sealing system, provides a stable and accurate sealing gas flow rate for the sealing system at different operating stages, avoids frequent overheating of the dry gas sealing heater, and eliminates potential safety hazards caused by human operation.

[0109] This invention provides a processor configured to execute a control method for a compressor unit according to the above embodiments.

[0110] like Figure 2As shown, this embodiment of the invention provides a control device for a compressor unit. The compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system provides sealing gas to the compressor body and includes a regulating valve. The control device includes: a pressure detection device 210 for detecting the internal pressure of the compressor body; a flow detection device 220 for detecting the current flow rate of the sealing gas in the dry gas sealing system; and a processor 230 according to the above embodiment. Understandably, the processor 230 is configured to execute the control method for the compressor unit according to the above embodiment.

[0111] This invention provides a compressor unit, including: a compressor body; a dry gas sealing system for supplying sealing gas to the compressor body, including a regulating valve; and a control device for the compressor unit according to the above embodiments.

[0112] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0113] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0114] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0115] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0116] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0117] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0118] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0119] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0120] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A control method for a compressor unit, characterized in that, The compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system is used to supply sealing gas to the compressor body. The dry gas sealing system includes a regulating valve. The control method includes: The internal pressure of the compressor body, the operating condition information of the compressor unit, and the current flow rate of the sealing gas in the dry gas sealing system are obtained. The target flow rate of the sealing gas in the dry gas sealing system is determined based on the internal pressure. The target opening adjustment strategy for the regulating valve is determined based on the internal pressure and the operating condition information. If the current flow rate is not equal to the target flow rate, the opening of the regulating valve is adjusted according to the target opening adjustment strategy to control the current flow rate at the target flow rate. The step of determining the target opening adjustment strategy for the regulating valve based on the internal pressure and the operating condition information includes: Determine the pressure range in which the internal pressure is located; Based on a preset correspondence, the corresponding adjustment time interval and adjustment opening ratio are determined according to the pressure range and the operating condition information, wherein the preset correspondence is the relationship between the pressure range, the operating condition information, the adjustment time interval, and the adjustment opening ratio. The target opening adjustment strategy is determined to be to increase the adjustment opening ratio at each adjustment time interval.

2. The control method according to claim 1, characterized in that, Determining the target flow rate of the sealing gas in the dry gas sealing system based on the internal pressure includes: Determine the pressure range in which the internal pressure is located; The target flow rate is determined to be the preset target flow rate corresponding to the pressure range.

3. The control method according to claim 1, characterized in that, The operating condition information includes purging or pressurizing conditions, and the adjustment opening ratio of each pressure range corresponding to the purging or pressurizing conditions is positively correlated with the pressure value of each pressure range.

4. The control method according to claim 1, characterized in that, After adjusting the opening of the regulating valve according to the target opening adjustment strategy, the method further includes: Obtain the outlet pressure and inlet pressure of the compressor body; The dry gas sealing system is determined to be in a preset stable state based on the outlet pressure, the inlet pressure, and the current flow rate. The preset stable state is a state in which the difference between the outlet pressure and the inlet pressure is greater than a preset pressure difference and the current flow rate is greater than or equal to a preset steady-state flow rate. When the dry gas sealing system is in the preset stable state and the duration of maintaining the preset stable state reaches the preset duration, the flow rate of the sealing gas in the dry gas sealing system is controlled by PID.

5. The control method according to any one of claims 1 to 4, characterized in that, The control method further includes: Obtain the current temperature of the sealing gas within the dry gas sealing system; Determine the target temperature control strategy based on the current temperature; The temperature of the sealing gas in the dry gas sealing system is controlled according to the target temperature control strategy.

6. The control method according to claim 5, characterized in that, The dry gas sealing system further includes a heating device; the step of determining the target temperature control strategy based on the current temperature includes: When the current temperature is in the low-temperature range, the power of the heating device is controlled to a preset power. When the current temperature is in a non-low temperature range, the power of the heating device is controlled by PID according to the preset target temperature and preset PID coefficients to achieve temperature control of the sealing gas.

7. The control method according to claim 6, characterized in that, There are multiple low-temperature zones, and the preset power corresponding to each low-temperature zone is negatively correlated with the temperature value of each low-temperature zone.

8. The control method according to claim 6, characterized in that, The number of non-low temperature zones is multiple; the step of performing PID control on the power of the heating device based on a preset target temperature and preset PID coefficients includes: The power of the heating device is controlled by PID based on the preset target temperature corresponding to each of the non-low temperature ranges and the preset PID coefficients corresponding to each of the non-low temperature ranges.

9. The control method according to claim 1, characterized in that, The dry gas sealing system is equipped with a pressure boosting skid at its air supply port connecting to the outside environment. The pressure boosting skid includes multiple pressure boosting pumps. The control method further includes: Obtain the running time of each of the aforementioned booster pumps; The operating priority of each booster pump is updated according to the running time, wherein the operating priority is negatively correlated with the running time; The operation of each booster pump is controlled based on the stated operating priority.

10. The control method according to claim 1, characterized in that, The compressor units are multiple, and the multiple dry gas sealing systems are connected to the outside environment through a single booster skid for gas supply. The control method further includes: A target compressor unit is identified among the plurality of compressor units, wherein the target compressor unit is a compressor unit in a stable flow state of sealing gas; Control the target compressor unit to stop supplying gas through the booster skid, and control any compressor unit other than the target compressor unit among the plurality of compressors to supply gas through the booster skid.

11. A processor, characterized in that, It is configured to perform the control method for a compressor unit according to any one of claims 1 to 10.

12. A control device for a compressor unit, characterized in that, The compressor unit includes a compressor body and a dry gas sealing system. The dry gas sealing system is used to supply sealing gas to the compressor body. The dry gas sealing system includes a regulating valve. The control device includes: Pressure detection equipment is used to detect the internal pressure of the compressor body; A flow detection device is used to detect the current flow rate of the sealing gas within the dry gas sealing system; and The processor according to claim 11.

13. A compressor unit, characterized in that, include: Compressor body; A dry gas sealing system, used to supply sealing gas to the compressor body, includes a regulating valve; and The control device for a compressor unit according to claim 12.

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