Electric feed pump isolation method and electric feed pump isolation system thereof

Abstract

The invention relates to an electric feed pump isolation method and an electric feed pump isolation system thereof, and belongs to the field of thermal power generating unit feed pumps, and the method comprises the following steps: S1, when a unit is reduced to 50% of BMCR load, stopping a faulted feed pump, and checking that an air inlet electric door and a control valve of the feed pump are closed tightly; s2, after the rotating speed of the feed pump reaches 0, the electric feed pump is powered off; s3, pressure relief and drainage of the feed pump, closing a high-pressure door, closing a low-pressure door and closing an outlet electric door of the feed pump; s4, closing a manual door of a middle tap of the water feeding pump; s5, closing a manual dosing door at the inlet of the booster pump and the like; the device has the advantages that rapid and safe isolation maintenance of the electric feed pump is achieved, equipment damage is avoided, and the safety and economic benefits of unit operation are enhanced. Through the step-by-step pressure relief water drainage and isolation steps, it is ensured that the pressure in the system is effectively controlled before the water feeding pump is overhauled, and equipment damage or personnel injury caused by sudden pressure release is prevented.

Description

Technical Field

[0001] The invention relates to an isolation method for an electric water supply pump and belongs to the field of water supply pumps for thermal power units. Background Art

[0002] The operation of thermal power plants relies on a complex array of systems and equipment, among which feedwater pumps play a crucial role. They are responsible for transporting water from low-lying areas to high-lying areas to meet the needs of boilers for steam generation. However, due to the high temperatures, high pressures, and continuous operation of thermal power plants, feedwater pumps are subject to various failures during operation. These failures not only affect the power plant's power generation efficiency but can also lead to safety incidents.

[0003] Electric feedwater pumps are widely used in thermal power plants due to their high efficiency and ease of control. However, their complex mechanical structure and control system require meticulous maintenance when a malfunction occurs. A crucial step in this maintenance process is depressurization and draining, which involves releasing the water and pressure within the pump to ensure the safety of maintenance personnel. However, if this process is not handled properly, it can lead to a series of safety risks.

[0004] Among them, overpressure caused by reverse rotation of a feed pump is a serious safety hazard. During the shutdown or isolation of a feed pump, if the pump outlet valve is not closed tightly or the pressure in the system is improperly controlled, the internal pressure of the pump can rise rapidly, causing damage to the pump or pipeline, or even an explosion. Furthermore, reverse rotation of a feed pump can also lead to mechanical failures such as shaft breakage and bearing damage, further exacerbating the severity of the accident. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the present invention provides an isolation method for an electric water supply pump and an isolation system for the electric water supply pump. The technical solution of the present invention is:

[0006] A method for isolating an electric water supply pump comprises the following steps:

[0007] S1. When the unit load is reduced to 50% BMCR, shut down the faulty feedwater pump and check whether the feedwater pump's air inlet electric door and regulating valve are tightly closed;

[0008] S2. After the water pump speed reaches 0, the electric water pump is powered off;

[0009] S3. Depressurize and drain the water supply pump. Close the high-pressure valve first, then the low-pressure valve, and close the electric valve at the water supply pump outlet.

[0010] S4. Close the manual door of the middle tap of the water supply pump;

[0011] S5. Close the manual dosing door at the front pump inlet;

[0012] S6. Close the water pump reverse heating electric door;

[0013] S7. Close the minimum flow valve of the water supply pump and its front and rear stop valves;

[0014] S8. Slowly close the electric door at the feed pump inlet and make sure that the outlet pressure of the feed pump and the pre-pump does not increase. If the pressure increases, immediately open the electric door at the pre-pump inlet.

[0015] S9. Manually operate the water pump outlet electric door, booster tap electric door, intermediate tap manual door, reverse heating electric door, and the minimum flow valve front and rear stop doors and confirm that they are tightly closed. Then close the pre-pump inlet electric door to prevent overpressure in the pump.

[0016] S10. After isolating the water pump, shut off the power to the electric doors of the water pump outlet, the front pump inlet, the reverse heating electric door, the forward heating electric door, and the electric isolation doors before and after the minimum flow valve.

[0017] S11. Open the drain valve of the pre-pump body and the drain valve of the pre-pump inlet filter, and drain the water from the middle tap of the water pump at the same time;

[0018] S12. After the outlet pressure of the pre-pump drops to near 0 MPa and the return temperature of the sealing water of the water supply pump decreases, close the manual and electric doors of the sealing water at the driving and non-driving ends of the water supply pump; close the electric water supply pump exhaust butterfly valve, check that it is fully closed, close the drain electric door in front of the exhaust butterfly valve, and cut off the power to the electric door.

[0019] The step S9 also includes a step of determining whether the water pump is reversed, specifically: adding a determination function for the water pump reverse, which determines whether there is a possibility of reverse by monitoring the speed change rate ΔN(t).

[0020] The inversion judgment function comprises the following steps:

[0021] a. Calculate the real-time speed change rate ΔN(t) of the water feed pump;

[0022] b. Determine whether the speed N(t) of the water supply pump drops to 0;

[0023] c. If N(t) = 0, enter the reverse monitoring state;

[0024] d. In the reversal monitoring state, if ΔN(t)>0, the reversal alarm is triggered.

[0025] It also includes regular inspection and maintenance of the feedwater pump after it has been isolated.

[0026] It also includes real-time monitoring of the outlet pressure of the feed water pump and the inlet pressure of the fore pump during the isolation process of the feed water pump.

[0027] It also includes the use of an audible and visual alarm system to notify operators of possible reverse or other abnormal conditions during the isolation of the water pump.

[0028] An electric water supply pump isolation system for implementing the electric water supply pump isolation method includes:

[0029] Speed ​​monitoring module, used to monitor the real-time speed of the water feed pump;

[0030] The pressure monitoring module is used to monitor the outlet pressure of the water supply pump and the inlet pressure of the pre-pump; the reversal judgment module is used to judge whether there is a possibility of reversal based on the speed change rate; the alarm module is used to issue an alarm when signs of reversal are detected.

[0031] The reversal judgment module further includes a calculation unit for calculating the speed change rate ΔN(t) of the water supply pump.

[0032] The alarm module is an audible and visual alarm device, which is used to sound an alarm when a sign of reversal is detected.

[0033] The advantages of the present invention are: rapid and safe isolation and maintenance of the electric water supply pump is achieved, equipment damage is avoided, and the safety and economic benefits of the unit operation are enhanced.

[0034] Improved safety: Through gradual pressure relief, water discharge and isolation steps, the pressure in the system is effectively controlled before the water pump is repaired, preventing equipment damage or personal injury caused by sudden pressure release.

[0035] Reverse prevention: The introduction of a reverse judgment function can monitor and judge in real time whether the water supply pump is reversed. Once signs of reverse are detected, an alarm will be immediately issued and corresponding measures will be taken, thereby avoiding overpressure and other potential accidents caused by reverse.

[0036] Operational accuracy: Manual operation to confirm that each valve is tightly closed, as well as real-time monitoring of outlet and inlet pressures during the isolation process, improves operational accuracy and ensures the smooth progress of the isolation process.

[0037] Easy maintenance: Regular inspection and maintenance procedures help to promptly detect and resolve potential problems, reduce unexpected downtime, and improve the reliability and stability of the entire system.

[0038] High degree of automation: The design of the electric water pump isolation system integrates speed monitoring, pressure monitoring, reversal judgment and alarm modules, reducing the complexity and error rate of manual operation and improving the level of automation.

[0039] Real-time monitoring: The system can monitor key parameters of the water supply pump in real time, such as speed and pressure, allowing operators to respond quickly to various situations and improve emergency handling capabilities.

[0040] Sound and light alarm system: The sound and light alarm system can promptly notify operators of possible reversal or other abnormal situations, improving on-site response speed and ensuring the safety of operators and equipment BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the main structure of the system of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are merely exemplary and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solutions of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, and such modifications and replacements fall within the scope of protection of the present invention.

[0043] See also Figure 1 The present invention relates to an isolation method for an electric water supply pump, comprising the following steps: S1. When the unit is reduced to 50% BMCR load, stop the faulty water supply pump and check whether the water supply pump air inlet electric door and the regulating valve are tightly closed; S2. After the water supply pump speed reaches 0, cut off the power supply to the electric water supply pump; S3. Depressurize and drain the water supply pump, first close the high-pressure door, then close the low-pressure door, and close the water supply pump outlet electric door; S4. Close the water supply pump middle tap manual door; S5. Close the pre-pump inlet dosing manual door; S6. Close the water supply pump reverse warming electric door; S7. Close the water supply pump minimum flow valve and its front and rear stop valves; S8. Slowly close the water supply pump pre-pump inlet electric door; S9. Manually operate the water supply pump outlet electric door, the boost stage tap electric door, the middle tap manual door, the reverse warming electric door, the boost stage tap electric door, the middle tap manual door, the reverse warming electric door, the boost stage tap electric door, the intermediate ... reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric door, the reverse warming electric After confirming that the electric door and the stop doors before and after the minimum flow valve are tightly closed, close the electric door at the inlet of the pre-pump to prevent overpressure in the pump; S10. After the water supply pump is isolated, cut off the power supply to the electric door at the outlet of the water supply pump, the electric door at the inlet of the pre-pump, the reverse heating electric door, the positive heating electric door, and the electric isolation door before and after the minimum flow valve; S11. Open the drain gate of the pre-pump body and the drain gate of the pre-pump inlet filter, and drain the water from the middle tap of the water supply pump at the same time (usually 1 to 2 times); S12. After the outlet pressure of the pre-pump drops to near 0MPa and the return water temperature of the sealing water of the water supply pump drops, close the manual door and electric door of the sealing water at the drive end and non-drive end of the water supply pump; close the exhaust butterfly valve of the electric water supply pump, check that it is fully closed, close the drain electric door in front of the exhaust butterfly valve, and cut off the power supply to the electric door.

[0044] The step S9 also includes a step of determining whether the water pump is reversed, specifically: adding a determination function for the water pump reverse, which determines whether there is a possibility of reverse by monitoring the speed change rate ΔN(t).

[0045] The inversion judgment function comprises the following steps:

[0046] a. Calculate the real-time speed change rate ΔN(t) of the water feed pump;

[0047] b. Determine whether the speed N(t) of the water supply pump drops to 0;

[0048] c. If N(t) = 0, enter the reverse monitoring state;

[0049] d. In the reversal monitoring state, if ΔN(t)>0, the reversal alarm is triggered.

[0050] It also includes regular inspection and maintenance of the feedwater pump after it has been isolated.

[0051] It also includes real-time monitoring of the outlet pressure of the feed water pump and the inlet pressure of the fore pump during the isolation process of the feed water pump.

[0052] It also includes the use of an audible and visual alarm system to notify operators of possible reverse or other abnormal conditions during the isolation of the water pump.

[0053] The present invention also relates to an electric water supply pump isolation system for implementing the electric water supply pump isolation method, comprising:

[0054] Speed ​​monitoring module 1, used to monitor the real-time speed of the water supply pump;

[0055] The pressure monitoring module 2 is used to monitor the outlet pressure of the water supply pump and the inlet pressure of the pre-pump; the reversal judgment module 3 is used to judge whether there is a possibility of reversal based on the speed change rate; the alarm module 4 is used to issue an alarm when signs of reversal are detected.

[0056] The reversal judgment module 3 further includes a calculation unit for calculating the speed change rate ΔN(t) of the water supply pump.

[0057] The alarm module 4 is an audible and visual alarm device, which is used to sound an alarm when a sign of reversal is detected.

[0058] In the present invention, by providing the isolation method and isolation system of the electric water supply pump, the following are achieved:

[0059] Gradual Isolation: The feedwater pump is safely isolated by gradually reducing the unit load, shutting down the faulty pump, releasing pressure and draining the water, closing relevant valves, and shutting off the power. This step-by-step approach prevents equipment damage or abnormal system pressure caused by hasty operation.

[0060] Prevent reverse rotation: After the water pump speed drops to 0, a reverse judgment function is added to monitor the pump speed change rate in real time. Once an increasing trend in speed is detected, it is considered that reverse rotation may occur. At this time, the system will trigger an alarm to avoid overpressure and other potential dangers caused by reverse rotation.

[0061] Real-time monitoring: During the entire isolation process, the system will monitor the outlet pressure of the water pump and the inlet pressure of the front pump in real time to ensure that no pressure abnormalities occur during the isolation process and ensure the safety of operation.

[0062] Sound and light alarm system: Through the sound and light alarm system, operators can be informed of the occurrence of reversal or other abnormal situations in a timely manner, so that they can take countermeasures quickly, improving the system's response speed and operational safety.

[0063] Regular inspection and maintenance: The isolation method also includes regular inspection and maintenance of the water supply pump after isolation, which helps to detect and solve potential problems in time, reduce future failure rates, and extend the service life of the equipment.

[0064] Automation system integration: The electric water pump isolation system integrates speed monitoring, pressure monitoring, reversal judgment and alarm functions into one system, which improves the degree of automation of operation and reduces errors and omissions in human operation.

[0065] The technical effect of the present invention is to improve the safety and reliability of the isolation process of the water supply pump of the thermal power plant, reduce equipment damage and safety accidents caused by improper operation, and also improve the operating efficiency of the equipment and the convenience of maintenance.

[0066] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for isolating an electric water supply pump, characterized in that: The following steps are involved: S1. When the unit is reduced to 50% BMCR load, stop the faulty feedwater pump and check whether the feedwater pump air intake electric door and regulating valve are closed tightly; S2. After the speed of the water supply pump reaches 0, the electric water supply pump is powered off; S3. Depressurize and drain the water supply pump, close the high-pressure door first, then the low-pressure door, and close the electric door at the outlet of the water supply pump; S4. Close the manual door of the middle tap of the water supply pump; S5. Close the manual dosing door at the front pump inlet; S6. Close the water pump reverse heating electric door; S7. Close the minimum flow valve of the water supply pump and its front and rear stop valves; S8. Close the electric door of the feed water pump pre-pump inlet; S9. Manually operate the electric door at the outlet of the water pump, the electric door at the booster stage tap, the manual door at the intermediate tap, the electric door at the reverse heating, and the stop doors before and after the minimum flow valve, and confirm that they are tightly closed, then close the electric door at the inlet of the front pump to prevent overpressure in the pump; S10. After the water supply pump is isolated, the electric door at the outlet of the water supply pump, the electric door at the inlet of the front pump, the reverse heating electric door, the positive heating electric door, and the electric isolation doors before and after the minimum flow valve are powered off; S11. Open the drain gate of the front pump body and the drain gate of the filter screen at the front pump inlet, and drain the water from the middle tap of the water supply pump at the same time; S12. After the outlet pressure of the pre-pump drops to close to 0MPa and the return temperature of the sealing water of the water pump decreases, close the manual and electric doors of the sealing water at the driving and non-driving ends of the water pump; close the electric water pump exhaust butterfly valve, check that it is fully closed, close the drain electric door in front of the exhaust butterfly valve, and cut off the power to the electric door.

2. The isolation method of the electric water supply pump according to claim 1, characterized in that: The step S9 also includes a step of determining the reverse rotation of the water pump, specifically, adding a determination function for the reverse rotation of the water pump, wherein the determination function determines whether there is a possibility of reverse rotation by monitoring the rotation speed change rate ΔN(t).

3. The isolation method of the electric water supply pump according to claim 2, characterized in that: The inversion judgment function comprises the following steps: a. Calculate the real-time speed change rate ΔN(t) of the water supply pump; b. Determine whether the speed N(t) of the water supply pump drops to 0; c. If N(t) = 0, enter the reverse monitoring state; d. In the reversal monitoring state, if ΔN(t)>0, the reversal alarm is triggered.

4. The isolation method of an electric water supply pump according to claim 1, characterized in that: It also includes regular inspection and maintenance of the feedwater pump after it is isolated.

5. The isolation method of the electric water supply pump according to claim 4, characterized in that: It also includes real-time monitoring of the outlet pressure of the feed pump and the inlet pressure of the fore pump during the isolation process of the feed pump.

6. The isolation method of the electric water supply pump according to claim 1, characterized in that: It also includes the use of an audible and visual alarm system to notify operators of possible reversal or other abnormal conditions during the isolation of the water pump.

7. An electric water supply pump isolation system for implementing the electric water supply pump isolation method according to any one of claims 1 to 6, characterized in that: include: Speed ​​monitoring module, used to monitor the real-time speed of the water supply pump; Pressure monitoring module, used to monitor the outlet pressure of the water supply pump and the inlet pressure of the pre-pump; A reversal judgment module is used to judge whether there is a possibility of reversal according to the speed change rate; An alarm module is used to sound an alarm when signs of reversing are detected.

8. The electric water pump isolation system according to claim 7, characterized in that: The reverse rotation determination module further includes a calculation unit for calculating the rotation speed change rate ΔN(t) of the water supply pump.

9. The electric water pump isolation system according to claim 8, characterized in that: The alarm module is an audible and visual alarm device, which is used to sound an alarm when a sign of reversal is detected.

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