A method and system for group control of pump sets in a power workshop

Abstract

This invention discloses a method and system for group control of pump sets in a power workshop, relating to the field of pump set control technology. It aims to solve the problem of low overall automation in existing secondary pump set control methods. The method includes the following steps: S1, based on the running time of the secondary pumps involved in the control, determine the pump with the shortest start-up time, designated as the first pump; the PID control loop sends the adjusted output frequency to all pumps; S2, determine whether the output frequency of this pump reaches a first amplitude; if so, initiate a first judgment process to determine whether to start the second pump; S3, based on the output frequencies of the first and second pumps, use a second judgment process to determine whether to start the third pump or stop the pump with the longest running time. This invention significantly improves the level of automation, not only greatly reducing the workload of operators and the need for manual intervention, but also making the overall system operation more stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of pump control technology, specifically to a method and system for group control of pump sets in a power workshop. Background Technology

[0002] In pharmaceutical power workshops, chilled water systems are core facilities ensuring stable operation of each workshop. Chiller units are supplied by the equipment manufacturer, and each unit can operate independently. The chilled water produced by the unit is pumped to a distributor / collector by a primary pump, and then distributed to the secondary pump sets. Currently, most companies' power workshops use two main modes for secondary pump control: First, when a single pump cannot meet the workshop's needs, operators must manually start a second pump in the DCS control system. In this case, one pump uses PID constant pressure control based on the outlet pressure (e.g., Chinese patent publication number CN208685705U), while the other uses fixed frequency control. If the pressure still cannot be met, operators must manually start a third pump and maintain fixed frequency control. Second, operators directly start two or more pump sets according to the production needs of the workshop, with each pump using constant pressure control based on the main outlet pipe pressure; secondary pumps cannot achieve coordinated adjustment.

[0003] The two secondary pump control modes described above share many common and unique drawbacks. Both have low overall automation levels and require manual start-up and shutdown by operators, significantly increasing their workload and making it prone to inappropriate start-up and shutdown timing due to delays or errors in manual judgment, hindering precise adaptation to dynamic changes in workshop load. In the first mode, only one pump participates in PID constant pressure control, while the remaining pumps operate at fixed frequency. This makes it impossible to finely adjust the operating status according to the actual load, easily leading to energy waste due to over-engineering. Furthermore, the combination of fixed-frequency and variable-frequency pumps can easily cause hydraulic mismatch issues. The second mode… In both modes, multiple pumps simultaneously perform constant pressure control based on the main pipe pressure, which can easily lead to mutual interference between the pumps, causing significant fluctuations in system pressure and flow. At the same time, both modes lack overall planning based on operating time, which can easily result in some pumps operating at high frequency for a long time while others are idle for a long time. This leads to uneven wear and tear on the pump set, and the pumps that operate frequently will fail prematurely due to excessive wear and tear, increasing the frequency and cost of equipment maintenance, reducing the overall service life of the pump set, and ultimately making it difficult to reliably guarantee the precise requirements of the pharmaceutical workshop for cold water supply. It may even indirectly affect the stable operation of production equipment. Summary of the Invention

[0004] This invention solves the problem of low overall automation in existing secondary pump group control methods, and proposes a group control method and system for power workshop pump groups, which significantly improves the level of automated operation. It not only greatly reduces the workload of operators and the need for manual intervention, but also makes the overall system operation more stable and reliable.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for group control of pump sets in a power workshop, comprising the following steps: S1, based on the running time of the secondary pumps involved in the control, determine the pump with the shortest start-up time, and record it as the first pump. The PID control loop will send the adjusted output frequency to all pumps. S2, determine whether the output frequency of the pump has reached the first amplitude. If so, start the first judgment process to determine whether to start the second pump. S3, based on the output frequencies of the first and second pumps, uses a second judgment process to determine whether to start the third pump or stop the pump that has been running the longest.

[0006] In the technical solution of the present invention, when the first pump is started, if the frequency of the inverter of the first pump reaches the upper limit of the specified range and cannot stabilize the main pipe pressure at the set value, after monitoring for a set period of time, the second pump is started according to the first judgment process, and the third pump is started according to the same judgment process; when the frequency of the inverter of the pump group drops to the lower limit of the specified range and the main pipe pressure continues to be higher than the set value for a set time, the pumps are gradually shut down according to the running time sequence.

[0007] The present invention is further configured such that step S2 includes: if the output frequency of the first pump does not reach the first amplitude, the PID control loop maintains the main pipe pressure stability by fine-tuning the output frequency of the pump.

[0008] In this technical solution, it is determined whether the output frequency of the first pump is less than the first amplitude. If it is less than the first amplitude, then the single pump operation is maintained.

[0009] The present invention is further configured such that: the first determination process includes: S21, when the total PID output frequency is greater than or equal to the first amplitude, the timing program is automatically triggered; S22, if the timing duration reaches the set threshold and the output frequency is still greater than or equal to the first amplitude, the second pump will be automatically started in order of the cumulative running time of each pump from shortest to longest.

[0010] In this technical solution, if the total PID output frequency is not less than the first amplitude, the system can trigger the timing program. After the corresponding timing period, if the output frequency is still not less than the first amplitude, the second pump will be started.

[0011] The present invention is further configured such that: the second judgment process of step S3 includes a continued start-up process and a shutdown process, wherein the shutdown process includes: after the total PID output frequency drops to the second amplitude, a timing program is started; if the timing duration reaches a set threshold and the output frequency is still less than the second amplitude, the pump with the longest running time is stopped according to the pump grouping order.

[0012] In this technical solution, if the total PID output frequency is less than the second amplitude, the timing program is started. If the output frequency is still less than the second amplitude after the corresponding timing period, the corresponding pump needs to be stopped.

[0013] The present invention is further configured such that step S1 includes: during the pump start-up control phase, the pumps are started sequentially in order of shortest to longest running time, based on the pump set outlet main pipe pressure and the cumulative running time of each pump.

[0014] The present invention is further configured such that after the first pump is started, the group control module is connected to the PID control loop and enters the automatic control mode.

[0015] The present invention is further configured such that: the continued startup process is based on the output frequency of the first pump and the second pump, and performs the same logical judgment as the first judgment process, to finally determine whether to start the third pump.

[0016] In this technical solution, the process for determining whether to start the third pump is the same as the process for determining whether to start the second pump.

[0017] A power workshop pump group control system, applicable to the aforementioned power workshop pump group control method, includes a group control module and a PID control loop connected to the group control module. The PID control loop performs unified control of the entire pump group. The group control module is connected to all secondary pump groups, and the secondary pump groups include several secondary pumps.

[0018] In this technical solution, the group control module is based on the pump group control algorithm to uniformly group all secondary pumps and build a PID control loop to achieve precise control of the pump group.

[0019] The present invention is further configured such that: the group control module has control authority over all bound pumps and is uniformly responsible for issuing start / stop commands and adjusting the operating frequency of the pump group.

[0020] In this technical solution, the group control module groups all pumps together and builds a PID control loop.

[0021] The present invention is further configured such that: the PID control loop performs closed-loop regulation with the pump outlet main pipe pressure setpoint as the control target, and synchronously sends the regulated output frequency to the frequency converters of all operating pumps.

[0022] The present invention provides a method for group control of pump sets in a power workshop, which can bring the following beneficial effects: This invention relates to a pump group control method for power workshops, which significantly improves the level of automation. It not only drastically reduces the workload of operators and the need for manual intervention, but also makes the overall system operation more stable and reliable. Furthermore, since the demands of the production workshop are dynamic, this algorithm can respond to these changes in real time. By continuously monitoring the main pipe pressure, it can promptly add or remove pumps, flexibly adapting to different operating conditions. This dynamic adjustment method also avoids energy waste and improves the operating efficiency of the pump groups. Attached Figure Description

[0023] Figure 1 This is a flowchart of a power workshop pump group control method according to the present invention.

[0024] Figure 2 This is a flowchart of the second judgment process of a power workshop pump group control method according to the present invention.

[0025] Figure 3 This is a first schematic diagram illustrating the applicable scenario of the power workshop pump group control method of the present invention.

[0026] Figure 4 This is a second schematic diagram illustrating the applicable scenario of the power workshop pump group control method of the present invention.

[0027] Attached reference numeral: 1. First chiller unit 2. Second chiller unit 3. Plate heat exchanger 4. Primary pump A 4-1, First primary pump A 4-2, Secondary Pump A 4-3, Third primary pump A 5. Primary pump B 5-1, First primary pump B 5-2, Secondary Pump B 6. Water collector 7. Bypass pipe 8. Water distributor 9. Secondary pump A 9-1, First and Secondary Pumps A 9-2, Secondary Pump A 9-3, Secondary Pump A 10. Secondary pump B 10-1, First and Secondary Pumps B 10-2, Secondary Pump B 10-3, Secondary Pump B 11. Secondary pump C 11-1, First and Secondary Pumps C 11-2, Secondary Pump C 12. Secondary pump D 12-1, First and Secondary Pumps D 12-2, Secondary Pump D. Detailed Implementation

[0028] Example 1 To address the technical problem of low overall automation in secondary pump group control methods, this embodiment proposes a group control method for power workshop pump groups, referencing... Figure 1 and Figure 2 It mainly includes the following steps.

[0029] Step S1: Based on the running time of the secondary pumps involved in the control, determine the pump with the shortest start-up time and designate it as the first pump. The PID control loop will then send the adjusted output frequency to all pumps.

[0030] More specifically, during the pump start-up control phase, the pumps are started sequentially in order of shortest to longest operating time, based on the pressure of the main outlet pipe of the pump set and the cumulative operating time of each pump.

[0031] Based on the pump group control algorithm, all secondary pumps can be uniformly grouped and a PID control loop can be built to achieve precise control of the pump group. After being put into operation, the system will prioritize starting the first pump based on the cumulative running time of each pump. At the same time, the PID control loop will switch to automatic mode, perform closed-loop regulation with the pump outlet main pipe pressure setpoint as the control target, and synchronously send the regulated output frequency to the frequency converters of all operating pumps.

[0032] After the first pump starts, the group control module connects to the PID control loop and enters the automatic control mode.

[0033] Step S2: Determine whether the output frequency of the first pump is not less than the first amplitude. If so, start the first judgment process to determine whether to start the second pump.

[0034] In one case of step S2, if the output frequency of the first pump is less than the first amplitude, the output frequency of the first pump can be fine-tuned through the PID control loop. The output frequency is continuously fine-tuned to maintain the main pipe pressure constant and the system maintains stable operation.

[0035] In this technical solution, it is determined whether the output frequency of the first pump is less than the first amplitude. If it is less than the first amplitude, then the single pump operation is maintained.

[0036] In another case of step S2, if the output frequency of the first pump is greater than or equal to the first amplitude, then the second pump is started through the first judgment process.

[0037] Specifically, the first judgment process mainly includes the following steps.

[0038] Step S21: When a single pump is running at full load and still cannot meet the production load demand, the system will automatically trigger the timing program after the total PID output frequency is greater than or equal to the first amplitude.

[0039] In step S22, if the timing duration reaches the set threshold and the output frequency is still in the high limit amplitude range (i.e., greater than or equal to the first amplitude), the system will automatically put the second pump into operation in order of the cumulative running time of each pump from shortest to longest.

[0040] In this technical solution, if the total PID output frequency is not less than the first amplitude, the system can trigger the timing program. After the corresponding timing period, if the output frequency is still not less than the first amplitude, the second pump will be started.

[0041] Step S3: Based on the output frequencies of the first and second pumps, a second judgment process is used to determine whether to start the third pump or stop the pump with the longest running time.

[0042] The second judgment process in step S3 mainly includes the start-up process and the shutdown process. The shutdown process includes the following steps: When the output capacity of the currently running pump group exceeds the production load demand, and the total PID output frequency drops to the lower limit amplitude value (second amplitude value), the system synchronously starts the timing program. If the timing duration reaches the set threshold and the output frequency is still in the lower limit amplitude range (less than the second amplitude value), the system stops the pump with the longest running time according to the pump grouping order.

[0043] In this technical solution, if the total PID output frequency is less than the second amplitude, the timing program is started. If the output frequency is still less than the second amplitude after the corresponding timing period, the corresponding pump needs to be stopped.

[0044] The startup process continues based on the output frequencies of the first and second pumps, and performs the same logical judgment as the first judgment process to finally determine whether to start the third pump.

[0045] In this technical solution, the process for determining whether to start the third pump is the same as the process for determining whether to start the second pump.

[0046] In the technical solution of the present invention, when the first pump is started, if the frequency of the inverter of the first pump reaches the upper limit of the specified range and cannot stabilize the main pipe pressure at the set value, after monitoring for a set period of time, the second pump is started according to the first judgment process, and the third pump is started according to the same judgment process; when the frequency of the inverter of the pump group drops to the lower limit of the specified range and the main pipe pressure continues to be higher than the set value for a set time, the pumps are gradually shut down according to the running time sequence.

[0047] During the pump start-up control phase, the system starts the pumps sequentially according to the total outlet pressure of the pump group and the cumulative running time of each pump, in ascending order of running time. Once the first pump is started, it immediately enters automatic control mode via a PID control loop. If the frequency of the pump's inverter is within the specified range and can stably maintain a constant total pressure, it remains in single-pump operation. If the first pump reaches the upper limit of the specified range under automatic control but still cannot stabilize the total pressure at the set value, the system will automatically start the second pump in the order of running time after continuous monitoring for a set period, and then achieve coordinated control of the two pumps through PID control. If the outlet pressure still does not meet the standard, the system will continue to start subsequent pump groups in sequence according to this logic until the pressure requirement is met. When multiple pumps are running in parallel, if the inverter frequency drops to the lower limit of the specified range and the total pressure remains higher than the set value for a set period, the system will gradually shut down the pumps in the order of running time.

[0048] During PID dynamic adjustment, due to the continuous fluctuation of the production workshop load, the system will determine and switch to three operating states in real time: First, if the operation of a single pump can meet the production load demand, the PID maintains a constant main pipe pressure by continuously fine-tuning the output frequency, and the system maintains stable operation; Second, if the operation of a single pump at full load still cannot match the production load demand, when the total PID output frequency reaches the high limit value, the system automatically triggers a timing program. If the timing duration reaches the set threshold and the output frequency is still in the high limit range, the system will automatically start the second pump in order of the shortest to the longest cumulative running time; Third, if the output capacity of the currently operating pump group exceeds the production load demand, when the total PID output frequency drops to the low limit value, the system synchronously starts a timing program. If the timing duration reaches the set threshold and the output frequency is still in the low limit range, the system will automatically stop the second pump in the order of pump grouping.

[0049] Through the above dynamic control logic, the number of operating pumps can be automatically optimized and adjusted based on the real-time load changes in the production workshop, while accurately maintaining a constant main pipe pressure, so as to achieve the optimal balance between system operating efficiency and energy consumption.

[0050] Example 2 This embodiment proposes a method for group control of pump sets in a power workshop, which mainly includes the following steps.

[0051] Step S1: Based on the running time of the secondary pumps involved in the control, determine the pump with the shortest start-up time and designate it as the first pump. The PID control loop will then send the adjusted output frequency to all pumps.

[0052] More specifically, during the pump start-up control phase, the pumps are started sequentially in order of shortest to longest operating time, based on the pressure of the main outlet pipe of the pump set and the cumulative operating time of each pump.

[0053] Based on the pump group control algorithm, all secondary pumps can be uniformly grouped and a PID control loop can be built to achieve precise control of the pump group. After being put into operation, the system will prioritize starting the first pump based on the cumulative running time of each pump. At the same time, the PID control loop will switch to automatic mode, perform closed-loop regulation with the pump outlet main pipe pressure setpoint as the control target, and synchronously send the regulated output frequency to the frequency converters of all operating pumps.

[0054] After the first pump starts, the group control module connects to the PID control loop and enters the automatic control mode.

[0055] Step S2: Determine whether the output frequency of the first pump is not less than the first amplitude. If so, start the first judgment process to determine whether to start the second pump.

[0056] In one case of step S2, if the output frequency of the first pump is less than the first amplitude, the output frequency of the first pump can be fine-tuned through the PID control loop. The output frequency is continuously fine-tuned to maintain the main pipe pressure constant and the system maintains stable operation.

[0057] In this technical solution, it is determined whether the output frequency of the first pump is less than the first amplitude. If it is less than the first amplitude, then the single pump operation is maintained.

[0058] In another case of step S2, if the output frequency of the first pump is greater than or equal to the first amplitude, then the second pump is started through the first judgment process.

[0059] Specifically, the first judgment process mainly includes the following steps.

[0060] Step S21: When a single pump is running at full load and still cannot meet the production load demand, the system will automatically trigger the timing program after the total PID output frequency is greater than or equal to the first amplitude.

[0061] In step S22, if the timing duration reaches the set threshold and the output frequency is still in the high limit amplitude range (i.e., greater than or equal to the first amplitude), the system will automatically put the second pump into operation in order of the cumulative running time of each pump from shortest to longest.

[0062] In this technical solution, if the total PID output frequency is not less than the first amplitude, the system can trigger the timing program. After the corresponding timing period, if the output frequency is still not less than the first amplitude, the second pump will be started.

[0063] Step S3: Based on the output frequencies of the first and second pumps, a second judgment process is used to determine whether to start the third pump or stop the pump with the longest running time.

[0064] The second judgment process in step S3 mainly includes the start-up process and the shutdown process. The shutdown process includes the following steps: When the output capacity of the currently running pump group exceeds the production load demand, and the total PID output frequency drops to the lower limit amplitude value (second amplitude value), the system synchronously starts the timing program. If the timing duration reaches the set threshold and the output frequency is still in the lower limit amplitude range (less than the second amplitude value), the system stops the pump with the longest running time according to the pump grouping order.

[0065] In this technical solution, if the total PID output frequency is less than the second amplitude, the timing program is started. If the output frequency is still less than the second amplitude after the corresponding timing period, the corresponding pump needs to be stopped.

[0066] The startup process continues based on the output frequencies of the first and second pumps, and performs the same logical judgment as the first judgment process to finally determine whether to start the third pump.

[0067] In this technical solution, the process for determining whether to start the third pump is the same as the process for determining whether to start the second pump.

[0068] In the technical solution of the present invention, when the first pump is started, if the frequency of the inverter of the first pump reaches the upper limit of the specified range and cannot stabilize the main pipe pressure at the set value, after monitoring for a set period of time, the second pump is started according to the first judgment process, and the third pump is started according to the same judgment process; when the frequency of the inverter of the pump group drops to the lower limit of the specified range and the main pipe pressure continues to be higher than the set value for a set time, the pumps are gradually shut down according to the running time sequence.

[0069] During the pump start-up control phase, the system starts the pumps sequentially according to the total outlet pressure of the pump group and the cumulative running time of each pump, in ascending order of running time. Once the first pump is started, it immediately enters automatic control mode via a PID control loop. If the frequency of the pump's inverter is within the specified range and can stably maintain a constant total pressure, it remains in single-pump operation. If the first pump reaches the upper limit of the specified range under automatic control but still cannot stabilize the total pressure at the set value, the system will automatically start the second pump in the order of running time after continuous monitoring for a set period, and then achieve coordinated control of the two pumps through PID control. If the outlet pressure still does not meet the standard, the system will continue to start subsequent pump groups in sequence according to this logic until the pressure requirement is met. When multiple pumps are running in parallel, if the inverter frequency drops to the lower limit of the specified range and the total pressure remains higher than the set value for a set period, the system will gradually shut down the pumps in the order of running time.

[0070] In pharmaceutical power workshops, the chilled water system is a core facility ensuring the stable operation of each workshop. The chilled water units are supplied by the equipment manufacturer, and each unit can operate independently. The chilled water produced by the units is pumped to the distributor and collector by a primary pump, and then distributed to the secondary pump sets. The secondary pump sets adopt a multi-pump parallel operation mode. The system can dynamically adjust the number of operating pump sets based on the operating time data of each pump collected by the DCS system and the actual load demand of the workshop, flexibly executing pump addition, reduction, and even complete shutdown operations, achieving optimal energy efficiency while precisely maintaining constant system pressure. This solution can efficiently adapt to dynamic changes in chilled water consumption in the workshop, ensuring production stability, significantly reducing system energy consumption, improving the automation level of the power workshop, and reducing the workload of operators. In addition, the PID centralized control mode effectively avoids the parameter fluctuation problems that are prone to occur when multiple pumps are independently adjusted, ensuring that key indicators such as system pressure and flow remain stable. Furthermore, the start-stop logic based on operating time sequencing can maximize the overall service life of the pump sets, reducing equipment maintenance frequency and costs.

[0071] Based on Example 1, this example also proposes a power workshop pump group control system, including a group control module and a PID control loop. The PID control loop is connected to the group control module and performs unified control of the entire pump group. The group control module is connected to all secondary pump groups, and the secondary pump groups include several secondary pumps.

[0072] In this technical solution, the group control module is based on the pump group control algorithm to uniformly group all secondary pumps and build a PID control loop to achieve precise control of the pump group.

[0073] The group control module has control permissions for all bound pumps and is responsible for issuing start / stop commands and adjusting the operating frequency of the pump group.

[0074] The PID control loop uses the pump outlet main pipe pressure setpoint as the control target for closed-loop regulation, and synchronously sends the regulated output frequency to the frequency converters of all operating pumps.

[0075] The PID control loop can perform dynamic adjustment processes, specifically including the following: Because the production workshop load is in a state of continuous fluctuation, the system will determine and switch to three operating states in real time: First, if a single pump can meet the production load demand, the PID maintains constant mains pressure by continuously fine-tuning the output frequency, and the system maintains stable operation; Second, if a single pump operating at full load still cannot match the production load demand, when the PID output frequency reaches the high frequency limit, the system automatically triggers a timing program. If the timing duration reaches the set threshold and the output frequency is still within the high limit range, the system will automatically start the second pump in order of the shortest to the longest cumulative running time; Third, if the output capacity of the currently operating pump group exceeds the production load demand, when the PID output frequency drops to the low frequency limit, the system synchronously starts a timing program. If the timing duration reaches the set threshold and the output frequency is still within the low limit range, the system will automatically stop the second pump according to the pump grouping order. Through the aforementioned dynamic control logic, this group control module can automatically optimize and adjust the number of operating pumps based on real-time load changes in the production workshop, while precisely maintaining a constant main pipe pressure, thereby achieving the optimal balance between system operating efficiency and energy consumption.

[0076] refer to Figure 3 and Figure 4 , Figure 3 and Figure 4 This is a schematic diagram of a secondary pump chilled water system with plate heat exchangers. After the chiller units (including the first chiller unit 1 and the second chiller unit 2) start up, they produce chilled water. The primary pumps (including primary pump A4 and primary pump B5; primary pump A4 includes the first primary pump A4-1, the second primary pump A4-2, and the third primary pump A4-3 connected in parallel; primary pump B5 includes the first primary pump B5-1, the second primary pump B5-2, and the third primary pump B5-3 connected in parallel) draw chilled water (including water flow that transfers cooling capacity through plate heat exchanger 3), pressurize it, and transmit it to the water collector 6. It is then delivered to the primary side water distributor 8 through the bypass valve 7. The plate heat exchanger transfers the cooling capacity to the secondary side water flow and cools it. After the chilled water from the side flows into the secondary side distributor, it is drawn and pressurized by the corresponding secondary pumps in each workshop (secondary pumps A9, B10, C11, and D12; secondary pump A9 includes first secondary pump A9-1, second secondary pump A9-2, and third secondary pump A9-3; secondary pump B10 includes first secondary pump B10-1, second secondary pump B10-2, and third secondary pump B10-3; secondary pump C11 includes first secondary pump C11-1 and second secondary pump C11-2; secondary pump D12 includes first secondary pump D12-1 and second secondary pump D12-2), and then transported through branch pipes to the cephalosporin workshop, the drug substitute workshop, the warehouse, and the power center workshops. Figure 4In the diagram, 'a' is the chilled water supply pipe for the spore-producing workshop, 'b' is the chilled water return pipe for the spore-producing workshop, 'c' is the chilled water supply pipe for the general medicine workshop, 'd' is the chilled water supply pipe for the general medicine workshop, 'e' is the chilled water supply pipe for the warehouse, 'f' is the chilled water return pipe for the warehouse, 'g' is the chilled water supply pipe for the power center, and 'h' is the chilled water return pipe for the power center.

[0077] A pressure transmitter is installed at the outlet manifold of the secondary pumps. This instrument can collect the pressure of the outlet manifold of the secondary pumps in real time and transmit it to the DCS control system. In the group control logic of this system, each secondary pump is not equipped with an individual PID control module, nor does it execute independent frequency conversion speed regulation or pressure control strategies. Instead, the secondary pumps corresponding to each workshop are grouped and integrated, and each pump group is equipped with a unified PID control loop. The operating time of each pump in the pump group is sorted according to the outlet manifold pressure of the secondary pumps, and the start-stop logic of adding or removing pumps is executed in ascending order of time. When the first pump cannot maintain the manifold pressure, the second pump in the pump group is automatically started to increase the system water supply capacity and raise the pressure. When the manifold pressure continues to be higher than the set value for a certain period of time, the pump with the longest operating time in the pump group is automatically shut down to reduce the system water supply load and lower the pressure. In this way, by controlling the start-stop of the pump group, the secondary side water supply pressure is accurately maintained and stabilized, while avoiding the complexity of independent adjustment of a single pump, ensuring the balance of cooling supply in the workshop, and thus achieving high efficiency and energy saving of pump group operation.

[0078] This embodiment offers the following technical advantages: 1. High degree of automation, requiring no manual intervention. Furthermore, centralized PID control avoids fluctuations caused by independent adjustment of multiple pumps, resulting in more stable system pressure; 2. Automatic pump addition / reduction control based on production workshop load ensures the pump set always operates within its high-efficiency range, effectively reducing energy consumption; 3. Start-stop logic based on running time sequencing maximizes the overall lifespan of the pump set and reduces maintenance frequency.

Claims

1. A method for group control of pump sets in a power workshop, characterized in that, Includes the following steps: S1, based on the running time of the secondary pumps involved in the control, determine the pump with the shortest start-up time, and record it as the first pump. The PID control loop will send the adjusted output frequency to all pumps. S2, determine whether the output frequency of the pump has reached the first amplitude. If so, start the first judgment process to determine whether to start the second pump. S3, based on the output frequencies of the first and second pumps, uses a second judgment process to determine whether to start the third pump or stop the pump that has been running the longest.

2. The method for group control of pump sets in a power workshop according to claim 1, characterized in that, Step S2 includes: if the output frequency of the first pump does not reach the first amplitude, the PID control loop fine-tunes the output frequency of the pump to maintain the stability of the main pipe pressure.

3. A method for group control of pump sets in a power workshop according to claim 1 or 2, characterized in that, The first judgment process includes: S21, when the total PID output frequency is greater than or equal to the first amplitude, the timing program is automatically triggered; S22, if the timing duration reaches the set threshold and the output frequency is still greater than or equal to the first amplitude, the second pump will be automatically started in order of the cumulative running time of each pump from shortest to longest.

4. The method for group control of pump sets in a power workshop according to claim 3, characterized in that, The second judgment process in step S3 includes a continued start-up process and a shutdown process. The shutdown process includes: after the total PID output frequency drops to the second amplitude, a timing program is started. If the timing duration reaches the set threshold and the output frequency is still less than the second amplitude, the pump with the longest running time is stopped according to the pump grouping order.

5. A method for group control of pump sets in a power workshop according to claim 1 or 2, characterized in that, Step S1 includes: during the pump start-up control phase, the pumps are started sequentially according to the pump set outlet main pipe pressure and the cumulative running time of each pump, in order of shortest to longest running time.

6. A method for group control of pump sets in a power workshop according to claim 1 or 2, characterized in that, After the first pump starts, the group control module connects to the PID control loop and enters the automatic control mode.

7. A method for group control of pump sets in a power workshop according to claim 4, characterized in that, The continued startup process determines whether to start the third pump based on the output frequencies of the first and second pumps and by performing the same logical judgment as the first judgment process.

8. A power workshop pump group control system, applicable to the power workshop pump group control method according to any one of claims 1-7, characterized in that, It includes a group control module and a PID control loop connected to the group control module. The PID control loop performs unified control of the entire pump group. The group control module is connected to all secondary pump groups, and the secondary pump groups include several secondary pumps.

9. A power workshop pump group control system according to claim 8, characterized in that, The group control module has control permissions for all bound pumps and is responsible for issuing start / stop commands and adjusting the operating frequency of the pump group.

10. A power workshop pump group control system according to claim 8 or 9, characterized in that, The PID control loop uses the pump outlet main pipe pressure setpoint as the control target for closed-loop regulation, and synchronously sends the regulated output frequency to the frequency converters of all operating pumps.

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