Method and control system for preventing electric fire pump of stable high-pressure fire water supply system from overcurrent trip

Abstract

The invention belongs to the field of stable high-pressure fire water supply systems, and particularly relates to a method and a control system for preventing an electric fire pump of a stable high-pressure fire water supply system from overcurrent trip, which can prevent the electric fire pump from trip caused by direct starting of the pump when the pressure of a fire pipe network is too low under an abnormal working condition through adjustment of an automatic control system. The pump starting time of the stable high-pressure fire water supply system during fire alarm operation under the abnormal working condition is saved, and the emergency reliability and the operation stability of the stable high-pressure fire water supply system under the abnormal working condition are improved.

Description

Technical Field

[0001] The present invention belongs to the field of stable high-pressure fire water supply system, and in particular relates to a method and a control system for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent. Background Art

[0002] The stable high-pressure fire water supply system is a fire water system that uses a pressure-stabilizing pump to maintain the fire water pressure of the pipe network greater than or equal to 0.7MPa. Usually, this function is achieved by controlling the pressure-stabilizing pump connected to the fire pipe network to automatically start and stop according to the pressure of the fire pipe network or by installing a pressure-holding pressure relief valve in the fire pipe network. When a fire alarm occurs, the fire water pump of the stable high-pressure fire water supply system automatically starts based on the pressure drop signal of the pipe network. According to the requirements of 8.3.8 of the "Design Fire Protection Standards for Petrochemical Enterprises": The main pump of the fire water pump should be an electric pump, and the standby pump should be a diesel engine pump.

[0003] In the prior art, when the stable high-pressure fire water supply system has an abnormal working condition and needs to be stopped for pressure relief, if a fire occurs during this period, especially when a fire hydrant has been opened at the fire scene, if the stable high-pressure fire water supply system is put into automatic operation at this time, after the electric fire pump fails to start due to overcurrent, only the diesel engine pump will start overload. If the requirements of 8.3.8 of the "Petrochemical Enterprise Design Fire Protection Standard" that the main pump of the fire water pump should be an electric pump and the standby pump should be a diesel engine pump are met, and the electric fire pump should be started first, it is necessary to close the outlet valve of the electric fire pump to a very small level in the manual state before starting. As the pressure of the pipeline network increases, it is also necessary to open the outlet valve of the electric fire pump without overcurrent. Manual operation is cumbersome and time-consuming, affecting fire safety. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method and a control system for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent.

[0005] The embodiment of the present invention provides a method for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent, comprising the following steps:

[0006] Step 1: Real-time monitoring of the status of the fire control cabinet, which is divided into automatic, stop, and manual; real-time monitoring of the motor current of each electric fire pump; real-time monitoring of the fire pipe network pressure; real-time monitoring of the status of the electric regulating valve at the outlet of each electric fire pump;

[0007] Step 2, when the fire control cabinet is in manual or stopped state, the monitoring module feeds back the state of the fire control cabinet to the control module, the control module intervenes, and the electric regulating valve at the outlet of the electric fire pump is closed to the set value SP1, wherein the set value SP1 is the valve position opening that does not exceed the rated current of the electric fire pump motor after the electric fire pump is started when the fire pipe network pressure is 0 or the fire pipe network pressure is the static water pressure of the fire water tank;

[0008] Step 3, when the fire control cabinet is in manual state and the electric fire pump is started to replenish the pressure of the fire pipe network, the control module intervenes, and the outlet electric regulating valve of the started electric fire pump is opened to the expected value SP2, wherein the expected value SP2 is the valve position opening when the actual current is equal to the rated current of the electric fire pump motor;

[0009] Step 4: When the fire control cabinet is in the automatic state and the fire pipe network pressure is higher than the set starting pressure of the last electric fire pump, the control module intervenes and all the electric regulating valves at the outlets of the electric fire pumps are fully opened;

[0010] Step 5: When the fire control cabinet is in automatic state and the fire pipe network pressure is lower than the set starting pressure of the last electric fire pump, the control module intervenes and the electric regulating valve at the outlet of the electric fire pump is closed to the expected value SP3, wherein the expected value SP3 is the valve position opening when the actual current is equal to the maximum working current of the electric fire pump motor.

[0011] The embodiment of the present invention provides a control system for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent, comprising:

[0012] The monitoring module is used to monitor the status of the fire control cabinet in real time; monitor the motor status and current of each electric fire pump in real time; monitor the pressure of the fire pipe network in real time; monitor the status of the electric regulating valve at the outlet of each electric fire pump in real time;

[0013] The control module is used to judge the status of the fire control cabinet and the status and current of each electric fire pump, and the opening status of the electric regulating valve at the outlet of the electric fire pump according to the data of the monitoring module, and adjust the opening of the electric regulating valve at the outlet of the electric fire pump according to the judgment situation;

[0014] The control module includes a controller and a plurality of start-stop control units corresponding to the electric regulating valves at the outlet of the electric fire pump. The start-stop control unit is configured to send start-stop control information to the controller to instruct the corresponding electric regulating valves at the outlet of the electric fire pump to open and close when the corresponding electric fire pump is stopped or running.

[0015] The control module also includes an operating parameter setting unit, which is configured to send parameter setting information to the controller to adjust the opening of the electric regulating valve at the outlet of the electric fire pump, and the operating parameters include the rated current of the electric fire pump motor and the maximum operating current of the electric fire pump motor.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention prevents the electric fire pump from jumping due to direct pumping when the fire pipe network pressure is too low under abnormal working conditions through the adjustment of the automatic control system, thereby saving the pump starting time of the stable high-pressure fire water supply system when the fire alarm is running under abnormal working conditions, and improving the emergency reliability and operation stability of the stable high-pressure fire water supply system when abnormal working conditions occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following describes an embodiment of a method and control system for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent with reference to the accompanying drawings.

[0019] Figure 1 A flow chart of a method for preventing an electric fire pump in a stable high-pressure fire water supply system from tripping due to overcurrent, provided in the first embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, they are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, if the descriptions of "first", "second", etc. are involved in the present invention, they are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments:

[0024] like Figure 1 As shown, the first embodiment of the present disclosure provides a method for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent, comprising the following steps:

[0025] Step 1: Real-time monitoring of the status of the fire control cabinet, which is divided into automatic, stop, and manual; real-time monitoring of the motor current of each electric fire pump; real-time monitoring of the fire pipe network pressure; real-time monitoring of the status of the electric regulating valve at the outlet of each electric fire pump;

[0026] Step 2, when the fire control cabinet is in manual or stopped state, the monitoring module feeds back the state of the fire control cabinet to the control module, the control module intervenes, and the electric regulating valve at the outlet of the electric fire pump is closed to the set value SP1, wherein the set value SP1 is the valve position opening that does not exceed the rated current of the electric fire pump motor after the electric fire pump is started when the fire pipe network pressure is 0 or the fire pipe network pressure is the static water pressure of the fire water tank;

[0027] Step 3, when the fire control cabinet is in manual state and the electric fire pump is started to replenish the pressure of the fire pipe network, the control module intervenes, and the outlet electric regulating valve of the started electric fire pump is opened to the expected value SP2, wherein the expected value SP2 is the valve position opening when the actual current is equal to the rated current of the electric fire pump motor;

[0028] Step 4: When the fire control cabinet is in the automatic state and the fire pipe network pressure is higher than the set starting pressure of the last electric fire pump, the control module intervenes and all the electric regulating valves at the outlets of the electric fire pumps are fully opened;

[0029] Step 5: When the fire control cabinet is in automatic state and the fire pipe network pressure is lower than the set starting pressure of the last electric fire pump, the control module intervenes, and the electric regulating valve at the outlet of the electric fire pump is closed to the expected value SP3, wherein the expected value SP3 is the valve position opening when the actual current is equal to the maximum working current of the electric fire pump motor;

[0030] The above steps are written into the PLC program to realize the electric fire pump current control and the electric regulating valve opening at the outlet of the electric fire pump.

[0031] Embodiment 2 of the present disclosure provides a control system for preventing an electric fire pump of a stable high-pressure fire water supply system from tripping due to overcurrent, comprising:

[0032] The monitoring module is used to monitor the status of the fire control cabinet in real time; monitor the motor status and current of each electric fire pump in real time; monitor the pressure of the fire pipe network in real time; monitor the status of the electric regulating valve at the outlet of each electric fire pump in real time;

[0033] The control module is used to judge the status of the fire control cabinet and the status and current of each electric fire pump, and the opening status of the electric regulating valve at the outlet of the electric fire pump according to the data of the monitoring module, and adjust the opening of the electric regulating valve at the outlet of the electric fire pump according to the judgment situation;

[0034] The control module includes a controller and multiple start-stop control units corresponding to the electric regulating valves at the outlet of the electric fire pump. The start-stop control unit is configured to send start-stop control information to the controller to instruct the corresponding electric regulating valves at the outlet of the electric fire pump to open and close when the corresponding electric fire pump is stopped or running.

[0035] The control module also includes an operating parameter setting unit, which is configured to send parameter setting information to the controller to adjust the opening of the electric regulating valve at the outlet of the electric fire pump. The operating parameters include the rated current of the electric fire pump motor and the maximum operating current of the electric fire pump motor.

[0036] It should be noted that the method and control system for preventing the electric fire pump of the stable high-pressure fire water supply system from tripping due to overcurrent does not change the start and stop logic of the pressure-stabilizing pump and the electric fire pump; the control system for preventing the electric fire pump of the stable high-pressure fire water supply system from tripping due to overcurrent can use the PLC or DCS of the original stable high-pressure fire water supply system as a control module.

[0037] The following are the operating instructions for the fire control cabinet:

[0038] First turn on the "power selection switch" to power the touch screen and PLC.

[0039] Fire control cabinet "stop" operation

[0040] Set "Auto / Stop / Manual" to "Stop". At this time, the electric fire pump loses power and the signal is fed back to the PLC. After a delay of 5 seconds, the electric regulating valve at the outlet of the electric fire pump is closed to the set value SP1. SP1 is displayed in percentage and can be set through the PLC.

[0041] Fire control cabinet manual operation

[0042] Put "Auto / Stop / Manual" on the "Manual" side. At this time, the electric fire pump is powered, and the signal is fed back to the PLC. After a delay of 5 seconds, the electric regulating valve at the outlet of the electric fire pump is closed to the set value SP1. SP1 is displayed as a percentage and can be set by the PLC. Press the "Start" button and "Stop" button of the pressure regulating pump to start and stop the 1# pressure regulating pump and the 2# pressure regulating pump in turn. The main circuits of the two pressure regulating pumps are directly started by the power frequency. If the pressure regulating pump cannot be started, it may be that the thermal relay is protected. You need to reset it manually by pressing the "reset" button on the thermal relay. Press the "Start" button and "Stop" button of the electric fire pump to start and stop the 1# electric fire pump and the 2# electric fire pump in turn. The main circuits of the two electric fire pumps are directly started by the power frequency. At this time, the water pressure signal and motor current signal of the fire pipe network are fed back to the PLC. The PLC controls the opening or closing of the electric regulating valve at the outlet of the electric fire pump until it is fully opened or closed to the expected value SP2 through the actual value of the motor current close to the rated current value.

[0043] Fire control cabinet automatic operation

[0044] Put "Auto / Stop / Manual" on the "Auto" side, and the two pressure-stabilizing pumps will run alternately according to the water pressure of the fire pipe network. The start and stop of the pressure-stabilizing pumps can be done through the pressure transmitter installed on the outlet main pipe of the two pressure-stabilizing pumps. Set the start and stop pressure values ​​of the pressure-stabilizing pumps through the parameter setting interface on the touch screen. The two pressure-stabilizing pumps run alternately and automatically. When any one fails, the other one will automatically start. The start pressure of the pressure-stabilizing pump is 0.8MPa, and the stop pressure is 1.2MPa. If any electric fire pump is running, the output of the pressure-stabilizing pump will be stopped. The start pressure of the first electric fire pump is 0.75MPa, and the start pressure of the second electric fire pump is 0.7MPa. The PLC receives the water pressure signal feedback of the fire pipe network and the motor current of each electric fire pump and the valve position feedback of the outlet electric regulating valve in real time. If the water pressure of the fire pipe network is greater than 0.7MPa, the valve position control opening of the outlet electric regulating valve of each electric fire pump is 100%. If the water pressure of the fire pipe network is less than 0.7MPa, the two electric fire pumps have been started, and the electric regulating valve at the outlet of the electric fire pump is closed to the expected value SP3. After the electric fire pump is started, if the output is insufficient, the pressure will continue to drop. At this time, the pressure will continue to be lower than the diesel engine pump starting pressure (preliminarily set at 0.5MPa). The PLC records this time for more than 60 seconds (the delay time is adjustable) and then starts the No. 1 diesel engine fire pump. If the pressure of the fire pipe network continues to decrease or the No. 1 diesel fire pump is in a fault state, the No. 2 diesel fire pump will be started. Automatic stop of the fire pump is not allowed.

[0045] The embodiments of the present invention have so far described the technical solutions of the present invention in conjunction with the preferred implementations shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific implementations. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for preventing an electric fire pump in a stable high-pressure fire water supply system from tripping due to overcurrent, characterized in that: The steps include: Step 1: Real-time monitoring of the status of the fire control cabinet, which is divided into automatic, stop, and manual; real-time monitoring of the motor current of each electric fire pump; real-time monitoring of the fire pipe network pressure; real-time monitoring of the status of the electric regulating valve at the outlet of each electric fire pump; Step 2, when the fire control cabinet is in manual or stopped state, the monitoring module feeds back the state of the fire control cabinet to the control module, the control module intervenes, and the electric regulating valve at the outlet of the electric fire pump is closed to the set value SP1, wherein the set value SP1 is the valve position opening that does not exceed the rated current of the electric fire pump motor after the electric fire pump is started when the fire pipe network pressure is 0 or the fire pipe network pressure is the static water pressure of the fire water tank; Step 3, when the fire control cabinet is in manual state and the electric fire pump is started to replenish the pressure of the fire pipe network, the control module intervenes, and the outlet electric regulating valve of the started electric fire pump is opened to the expected value SP2, wherein the expected value SP2 is the valve position opening when the actual current is equal to the rated current of the electric fire pump motor; Step 4: When the fire control cabinet is in the automatic state and the fire pipe network pressure is higher than the set starting pressure of the last electric fire pump, the control module intervenes and all the electric regulating valves at the outlets of the electric fire pumps are fully opened; Step 5: When the fire control cabinet is in automatic state and the fire pipe network pressure is lower than the set starting pressure of the last electric fire pump, the control module intervenes and the electric regulating valve at the outlet of the electric fire pump is closed to the expected value SP3, wherein the expected value SP3 is the valve position opening when the actual current is equal to the maximum working current of the electric fire pump motor.

2. A control system to prevent overcurrent tripping of electric fire pumps in a stable high-pressure fire water supply system, characterized in that: include: The monitoring module is used to monitor the status of the fire control cabinet in real time; monitor the motor status and current of each electric fire pump in real time; monitor the pressure of the fire pipe network in real time; monitor the status of the electric regulating valve at the outlet of each electric fire pump in real time; The control module is used to judge the status of the fire control cabinet and the status and current of each electric fire pump, and the opening status of the electric regulating valve at the outlet of the electric fire pump according to the data of the monitoring module, and adjust the opening of the electric regulating valve at the outlet of the electric fire pump according to the judgment situation; The control module includes a controller and a plurality of start-stop control units corresponding to the electric regulating valves at the outlet of the electric fire pump. The start-stop control unit is configured to send start-stop control information to the controller to instruct the corresponding electric regulating valves at the outlet of the electric fire pump to open and close when the corresponding electric fire pump is stopped or running. The control module also includes an operating parameter setting unit, which is configured to send parameter setting information to the controller to adjust the opening of the electric regulating valve at the outlet of the electric fire pump, and the operating parameters include the rated current of the electric fire pump motor and the maximum operating current of the electric fire pump motor.

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