A fire-resistant oil moisture monitoring system and control method

Abstract

The application discloses an anti-combustion oil moisture monitoring system and a control method. The method adopts an online monitoring technology, can directly and real-timely measure the moisture value in the anti-combustion oil after the anti-combustion oil intelligent maintenance system is operated, and overcomes the problems of poor timeliness and limited sample quantity in the existing anti-combustion oil filtering technology, i.e. the moisture is measured in a laboratory after sampling on site, so that the measurement result data are less. The use cost of equipment is greatly reduced, the service life of a dehydration filter core is prolonged under the condition that the moisture of the oil is qualified, intelligent control is realized, the operation is simple, and the problem of high labor intensity is solved.

Description

Technical Field

[0001] This invention belongs to the technical field of phosphate ester fire-resistant oil systems for steam turbine speed control systems, specifically relating to a moisture monitoring system and control method for fire-resistant oil. Background Technology

[0002] Phosphate ester fire-resistant oil is mainly used in the turbine speed control system of power system generator sets. Its primary function is to provide power and protective oil to the high and intermediate pressure steam valve actuators, regulating and controlling the steam intake of the high and intermediate pressure cylinders of the turbine, and operating the main steam valve actuators. With the rapid development of the power industry, the number of large-capacity, high-parameter steam turbine units is increasing, placing higher demands on the speed control system. This makes fire-resistant oil highly susceptible to exceeding standards for indicators such as moisture content during operation. To ensure the safe operation of the speed control system, the power industry has strict requirements for various indicators of fire-resistant oil during operation.

[0003] As an open hydraulic system operating for extended periods, fire-resistant oil systems require contact with air, making it inevitable that moisture from the air will enter the oil. The primary sources of moisture are absorption of airborne moisture, such as leaky tank covers or a malfunctioning desiccant in the air filter at the top of the tank. Moisture during the system filling process can also enter through the pump inlet, leaky containers, or water leakage from the oil cooler. Therefore, water removal is essential for the use of fire-resistant oil. Moisture causes the hydrolysis of phosphate esters, producing acidic phosphate esters and phenols. These acidic products have an autocatalytic effect, reacting with other substances in the oil to further generate low-molecular-weight acids and high-molecular-weight compounds. These acidic products then catalyze further decomposition of the oil, accelerating its degradation.

[0004] Currently, the main method for dehydration in fire-resistant oil systems at power plants is adsorption dehydration using dehydration filter cartridges. Improper operation and maintenance of this method can lead to significant costs in terms of labor and consumables. Determining whether the moisture content is within acceptable limits requires laboratory personnel to regularly sample and analyze the water, which is not only time-consuming but also wastes considerable manpower. The process requires close cooperation between maintenance and laboratory personnel, and the equipment must remain running until the test results are available, resulting in wasted equipment and consumables. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fire-resistant oil moisture monitoring system and control method to solve the technical problems of high cost and high labor intensity of fire-resistant oil moisture maintenance equipment in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A fire-resistant oil moisture monitoring system includes a pre-pump filter, an oil pump, a dehydrator, a primary precision filter, and a secondary precision filter connected in sequence.

[0008] The oil pump pre-filter is connected in parallel with an online moisture monitoring device, and the dehydrator is connected in parallel with a dehydration electric bypass valve. The dehydration electric bypass valve is preset with a moisture target value and a moisture excess value.

[0009] The outlet of the oil pump is connected to a system pressure transmitter and a system pressure gauge, and the system pressure gauge is connected to a system pressure alarm switch;

[0010] A pressure transmitter is installed between the dehydrator and the primary precision filter, and a pressure transmitter is installed between the primary precision filter and the secondary precision filter; a differential pressure alarm is connected in parallel to the secondary precision filter.

[0011] The online moisture monitoring device, system pressure transmitter, pressure transmitter before the first-stage precision filter, pressure transmitter before the second-stage precision filter, and differential pressure alarm are all connected to a PLC controller, which is located in the control cabinet.

[0012] A further improvement of the present invention is that:

[0013] Preferably, the oil pump pre-filter is equipped with a filter element of a specific precision; the standard displacement of the oil pump is 10L / min.

[0014] Preferably, the outlet of the oil pump is connected to a system pressure gauge, and the system pressure gauge is connected to a system pressure alarm switch; the system pressure alarm switch is connected to a PLC controller.

[0015] Preferably, the oil pump is connected in parallel with a relief valve, the high-pressure inlet of the relief valve is connected to the outlet of the oil pump, and the low-pressure return port of the relief valve is connected to the inlet of the oil pump; the relief valve is set to 2.5MPa full return oil.

[0016] Preferably, the primary precision filter contains four filter elements with a filtration accuracy of 5μm; the secondary precision filter contains one filter element with a filtration accuracy of 1μm.

[0017] Preferably, a pressure gauge is installed between the dehydrator and the primary precision filter, before the primary precision filter.

[0018] Preferably, a temperature transmitter is provided at the outlet of the secondary precision filter, and the temperature transmitter is connected to a PLC controller.

[0019] A control method for the above-mentioned fuel oil moisture monitoring system, the control method being: comparing P with A and comparing P with B; where P is the average value P of 6 real-time moisture data, A is the preset moisture target value of the dehydrating electric bypass valve, and B is the moisture over-limit value; the real-time moisture data is obtained through an on-line monitoring device; when P < A, the dehydrating electric bypass valve is opened; when P is greater than B, the dehydrating electric bypass valve is closed; when A < P < B, the dehydrating electric bypass valve remains in its current state unchanged.

[0020] Preferably, the method for judging the replacement of the filter element in the dehydrator is: closing the dehydrating electric bypass valve, collecting the moisture on-line monitoring device once every 24 hours, and replacing the filter element when any of the following conditions is met:

[0021] (1) When four consecutive numbers satisfy an increasing relationship and the latest data is greater than 800, prompt to replace the filter element;

[0022] (2) When the latest data is greater than 1200, prompt to replace the filter element.

[0023] Preferably, when the preset value of the system pressure alarm is greater than 2.5 MPa and the pressure difference of the secondary precision filter is greater than 0.35 MPa, the equipment alarms and stops.

[0024] When the temperature displayed by the temperature transmitter > 35 °C, when any one of the pressure differences of the dehydrator, the primary precision filter, and the secondary precision filter is greater than the preset alarm value, the equipment alarms and stops.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention discloses an anti-fuel-oil moisture monitoring system and a control method. This method uses on-line monitoring technology to directly and real-time measure the moisture value in the anti-fuel oil after the anti-fuel oil moisture intelligent maintenance system operates, overcoming the problems of poor timeliness in the existing anti-fuel oil filtration technology where manual sampling is first carried out on-site and then moisture determination is carried out in the laboratory, and limited sample quantity resulting in few measurement result data. It greatly reduces the usage cost of the equipment, extends the service life of the dehydrating filter element while maintaining the qualified moisture of the oil quality, realizes intelligent control, has simple operation, and solves the problem of large manual labor intensity.

[0027] Furthermore, this system can set parameters through the control cabinet display screen. After algorithm calculation in the controller, when the moisture is lower or higher than the set threshold value, different actions of the dehydrating bypass valve are triggered respectively, avoiding the continuous input of the dehydrating filter element after the moisture is qualified, and also enabling the dehydrating filter element to be automatically put into operation in time when the moisture is unqualified. This can not only ensure the qualified moisture index of the anti-fuel oil, but also extend the service life of the dehydrating filter element.

[0028] Furthermore, the system can continuously monitor the moisture content of the fire-resistant oil system 24 hours a day and automatically reduce the moisture content in a timely manner. When the dehydration filter element is about to fail, the display screen will automatically issue a replacement reminder. It is easy to operate, reducing the workload of laboratory personnel and equipment operators. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the intelligent moisture maintenance system for fire-resistant oil of the present invention;

[0030] Figure 2 This is the bypass valve operation logic diagram of the intelligent water retention system for fire-resistant oil of the present invention;

[0031] Figure 3 This is a logic diagram of the dehydration filter replacement system of the fire-resistant oil moisture intelligent maintenance system of the present invention;

[0032] The components are as follows: 1-Inlet valve; 2-Filter before oil pump; 3-Oil pump; 4-System pressure gauge; 5-System pressure alarm switch; 6-System pressure transmitter; 7-Oil pump outlet valve; 8-Dehydrator; 9-Pressure transmitter before primary precision filter; 10-Pressure gauge before primary precision filter; 11-Dehydrator electric bypass valve; 12-Primary precision filter; 13-Pressure transmitter before secondary precision filter; 14-Pressure gauge before secondary precision filter; 15-Differential pressure alarm for secondary precision filter; 16-Secondary precision filter; 17-Temperature transmitter; 18-Drain valve; 19-Relief valve; 20-Inlet valve; 21-Outlet valve; 22-Online moisture monitoring device; 23-Control cabinet; 24-Display screen; 25-Alarm light; 26-Reset button; 27-Start button; 28-Stop button. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings:

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] An embodiment of the present invention discloses an intelligent water retention system for fire-resistant oil, comprising: a pre-pump filter 2, an oil pump 3, a dehydrator 8, a primary precision filter 12, and a secondary precision filter 16; the pre-pump filter 2 is externally connected to an oil inlet pipeline, and the secondary precision filter 16 is externally connected to an oil outlet pipeline; the oil inlet pipeline is equipped with an oil inlet valve 1, and the oil outlet pipeline is equipped with an oil outlet valve 18 and a temperature transmitter 17; the oil inlet pipeline passes sequentially through the pre-pump filter 2, the oil pump 3, the dehydrator 8, the primary precision filter 12, and the secondary precision filter 16 and is connected to the oil outlet pipeline.

[0036] In an embodiment of the present invention, the pre-pump filter 2 is located between the inlet valve 1 and the oil pump 3, and is equipped with a 100-mesh filter element to filter large particles in the oil and protect the oil pump 3. The standard displacement of the oil pump 3 is 10L / min. As a preferred embodiment, the front end of the pre-pump filter 2 is provided with an inlet valve 1 for connecting an external oil inlet pipeline.

[0037] In an embodiment of the present invention, the oil pump 3 is connected to a motor to drive the directional flow of oil, with a standard discharge capacity of 10L / min.

[0038] In an embodiment of the present invention, the dehydrator 8 is used to install the dehydration filter element. The oil inlet pipeline is provided with a first bypass before and after the dehydrator 8. A dehydration electric bypass valve 11 is installed on the first bypass. One end of the first bypass is connected to the pipeline between the oil pump outlet valve and the dehydrator, and the other end is connected to the pipeline between the dehydrator and the first-stage precision filter. The dehydration electric bypass valve 11 and the dehydrator 8 are connected in parallel and are used to receive signals from the controller to control the insertion and removal of the dehydration filter element.

[0039] In this embodiment of the invention, an oil pump outlet valve 7 is provided between the oil pump 3 and the dehydrator 8. A system pressure gauge 4 and a system pressure transmitter 6 are connected to the outlet of the oil pump 3. The system pressure gauge 4 is connected to a system pressure alarm switch 5. The system pressure transmitter 6, system pressure gauge 4, and system pressure alarm switch 5 are located in the pipeline between the oil pump and the oil pump outlet valve. The system pressure gauge 4 is used to display the oil pump outlet pressure on-site. The system pressure alarm switch 5 is a mechanical structure with a preset pressure of 2.5 MPa, SPDT type electrical contacts, and is connected to the PLC controller in the control cabinet. When the measured system pressure exceeds the preset value, it prevents damage to the dehydration filter element due to excessive pressure. The system pressure transmitter 6 is connected to the PLC controller in the control cabinet to display system pressure data and simultaneously calculates the pressure difference value of the dehydrator 8 with the pressure transmitter 13 before the first-stage precision filtration within the program.

[0040] In an embodiment of the present invention, an overflow valve 19 is also provided. The high-pressure inlet side of the overflow valve 19 is connected to the oil pump 3 and the oil pump outlet valve 7, and the low-pressure return side of the overflow valve 19 is connected to the pipeline between the pre-pump filter 2 and the oil pump 3. The overflow valve 19 is set to 2.5MPa full return oil pressure.

[0041] In this embodiment of the invention, the primary precision filter 12 is equipped with four 5-micron precision filter elements to filter larger impurity particles. A pressure gauge 10 and a pressure transmitter 9 are installed between the dehydrator 8 and the primary precision filter 12. The pressure gauge 10 displays the pressure of the primary precision filter 12 on-site, while the pressure transmitter 9 transmits data to the PLC controller in the control cabinet 23. The PLC controller calculates the pressure difference value of the primary precision filter 12 with the pressure transmitter 13 before the secondary precision filter. The pressure transmitter 9 is connected to the PLC controller in the control cabinet to collect pressure data for program calculations and display the data on the screen.

[0042] In this embodiment of the invention, the secondary precision filter 16 is equipped with a 1-micron precision filter element to filter fine impurity particles, achieving the purpose of precision filtration of fire-resistant fuel and preventing impurities from being introduced into the fire-resistant fuel system during maintenance. A pressure transmitter 13 is installed between the primary precision filter 12 and the secondary precision filter 16. The pressure transmitter 13 is connected to the PLC controller in the control cabinet to display the pressure before the filter. The oil inlet pipeline is connected to a second bypass at the inlet and outlet of the secondary precision filter 16. A differential pressure alarm 15 and a pressure gauge 14 are installed on the second bypass. The high-pressure oil inlet side of the differential pressure alarm 15 is located in the pipeline between the secondary precision filter 16 and the primary precision filter 12, and the low-pressure oil inlet side is located in the pipeline between the secondary precision filter 15 and the drain valve 18. The differential pressure alarm 15 is a mechanical structure with a preset pressure of 0.35MPa. It has SPDT type electrical contacts and is connected to the PLC controller in the control cabinet 23. Once the differential pressure across the secondary precision filter 16 measured by the differential pressure alarm 15 exceeds the set range, the internal spring will activate to trigger an alarm. When the secondary precision filter 16 is clogged, the internal contacts of the alarm will activate to trigger an alarm signal. The pressure gauge 14 in front of the secondary precision filter is used to display the pressure in front of the filter on site.

[0043] In an embodiment of the present invention, a temperature transmitter 17 is provided between the secondary precision filter 16 and the oil drain valve 18 to collect the system outlet oil temperature and connect to the controller in the control cabinet for program calculation. As one of the preferred solutions, an oil drain valve is provided at the rear end of the secondary precision filter 16 for connecting an external oil outlet pipeline.

[0044] In an embodiment of the present invention, an online moisture monitoring device 22 is connected in parallel to the oil pump pre-filter 2 in the oil inlet pipeline. The oil inlet of the moisture detection device 22 is connected between the oil inlet valve 1 and the oil pump pre-filter 2 to prevent the foam generated after the oil entering the monitoring device passes through any filter screen from affecting the data monitoring. An oil inlet valve 20 is provided before the oil inlet of the moisture detection device 22. The oil outlet of the moisture detection device 22 is connected between the oil pump filter 2 and the oil pump 3. The oil driving pressure provided by the oil pump 3 and the negative pressure at its inlet can drive the oil to flow in the online moisture monitoring device 22. An oil outlet valve 21 is provided at the oil outlet of the moisture detection device 22. The core of the online moisture monitoring device 22 is a self-developed online near-infrared spectral sensor.

[0045] In this embodiment of the invention, the intelligent maintenance system is a control system, which includes a control cabinet 23 and a PLC controller located within the control cabinet. The PLC controller is connected to a motor 2, a system pressure transmitter 6, a system pressure alarm 5, a pressure transmitter 9 before the first-stage precision filter, an electric bypass valve 11 for the dehydrator, a pressure transmitter 13 before the second-stage precision filter, a differential pressure switch 15, a temperature transmitter 17, and an online moisture monitoring device 22. It also includes a display screen 24, an alarm light 25, a reset button 26, a start button 27, and a stop button 28 located on the control cabinet. In this system, the PLC controller is a programmable logic controller (PLC) and is a commercially available product.

[0046] The bypass valve control method and filter replacement logic of the intelligent maintenance system are the core algorithms, which are used in conjunction with other components of the maintenance system to form the intelligent moisture maintenance system.

[0047] like Figure 1 As shown, the working principle of this intelligent moisture maintenance system is as follows:

[0048] Connect the inlet valve 1 line to the bottom drain port of the fire-resistant oil system tank, and connect the drain valve 18 line to the top return port of the fire-resistant oil tank. Open the inlet valve 1, the pump outlet valve 7, and the drain valve 18 in sequence. Set the moisture control threshold range, the differential pressure alarm value of the dehydrator 8, the differential pressure alarm value of the first-stage precision filter 12, and the pressure alarm value of the second-stage precision filter 16 in sequence on the display screen. Click the start button 27 on the control cabinet. The pump 3 starts running, and the oil in the fire-resistant oil system tank comes out and enters the inlet line. The fire-resistant oil passes through the pre-pump filter 2 to remove large particulate impurities. After being pressurized by the pump 3, it enters the dehydrator 8, the first-stage precision filter 12, the second-stage precision filter 16, and the drain valve 18 in sequence at a flow rate of 10L / min. Then, it returns to the fire-resistant oil tank through the drain line. During this process, the use of the dehydrator 8 is adjusted according to the monitoring values. After the pressure of each filter stabilizes, open the oil inlet valve 20 of the moisture monitoring device 22 and the oil return valve 21 of the online moisture monitoring device 22. The display screen 24 of the control cabinet 23 will then show the operation of the online moisture monitoring device. At this time, the intelligent moisture maintenance system will be put into operation. Figure 2 , Figure 3 The system is in an intelligent maintenance state under the control of the logic algorithm shown.

[0049] The operating principle of the dehydration electric bypass valve 11 in this intelligent moisture maintenance system is as follows:

[0050] On the display screen, the dehydration electric bypass valve 11 presets the moisture target value A and the moisture over-limit value B. After the moisture intelligent system is turned on and the intelligent maintenance system has been running stably for 1 hour, the PLC controller starts to automatically save the real-time moisture data transmitted by the moisture online monitoring device 22, saving the current real-time data every 2 hours. When the amount of data reaches 6 consecutive times, these 6 consecutive data are averaged, and the calculation result is P. P is compared with A and B. P < A means that the water content in the oil is lower than the set value of this part, and dehydration is not required. Therefore, the dehydration electric bypass valve 11 is opened, and the oil flows through the second bypass. When P > B, it means that the water content in the oil is lower than the set value of this part, and the dehydration bypass valve is closed, and the oil is dehydrated through the dehydrator 8; when A < P < B, the dehydration electric bypass valve 11 maintains its current state, that is, if it was in the open state before, it remains in the open state without action; if it was in the closed state before, it remains in the closed state without action until the collected data P B triggers an action.

[0051] As Figure 3 shown, the present invention also discloses a method for judging whether to replace the dehydration filter element in the dehydrator 8.

[0052] During the operation of the moisture intelligent maintenance system and when the dehydration electric bypass valve 11 is in the closed state, the oil is always processed through the dehydrator 8. The PLC controller saves the real-time moisture data C monitored by the moisture online monitoring device 22 at the moment when the valve is closed. Based on this as a base point, data is saved every 24 hours for 72 hours, and data D, E, and F are collected. These four numbers are polled and updated every 24 hours. If the four continuously saved data satisfy an increasing relationship and the latest data is greater than 800, it is prompted to replace the filter element; otherwise, it is prompted that the filter element is normal. If the increasing relationship is not satisfied and the latest real-time data is greater than 1200, it is also prompted to replace the filter element.

[0053] The embodiments of the present invention disclose a monitoring method, including the following steps:

[0054] During the operation of the moisture intelligent maintenance system, if the system pressure exceeds the preset value of the system pressure alarm 5, which is 2.5 MPa, and the differential pressure of the secondary precision filter 16 exceeds the preset value of the differential pressure alarm of the secondary precision filter 15, which is 0.35 MPa, the equipment alarms and stops, and the alarm information is displayed; during the operation, when the data of the temperature transmitter 17 is higher than 35 °C, if the differential pressure values of the dehydrator and the primary precision filter respectively exceed the preset alarm values on the display screen, both will alarm and stop, and the alarm information will be displayed. The viscosity of the oil is significantly affected by temperature changes, and the viscosity is proportional to the pressure passing through the filter. Therefore, the differential pressure values of the dehydrator and the primary precision filter can accurately reflect the state of the filter element only when the oil temperature is above 35 degrees.

[0055] Specifically, the pressure difference value of the dehydrator 8 is calculated by the difference between the system pressure transmitter 6 and the pressure transmitter 9 before the first-stage precision filter; the pressure difference value of the first-stage precision filter 12 is calculated by the difference between the pressure transmitter 9 before the first-stage precision filter and the pressure transmitter 13 before the second-stage precision filter; and the pressure transmitter 13 before the second-stage precision filter reflects the pressure value of the second-stage precision filter 16.

[0056] The method of this invention collects real-time moisture data of fire-resistant oil using an online moisture monitoring device. Based on a preset logic algorithm, the system control cabinet calculates and automatically activates the dehydration bypass electric valve, thereby achieving automatic insertion and removal of the dehydration filter element. The method also alerts the user based on moisture data to indicate whether the filter element inside the filter has failed, thus realizing intelligent moisture maintenance of fire-resistant oil. The intelligent moisture maintenance system and control method for fire-resistant oil proposed in this invention can significantly reduce the rate of moisture growth during the use of fire-resistant oil, slow down the rate of oil quality deterioration, effectively extend the life of the dehydration filter, save on manual maintenance costs of the fire-resistant oil system, achieve intelligent control, and improve work efficiency and system safety.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method for a moisture monitoring system for fire-resistant oil, characterized in that, The fuel oil anti-moisture monitoring system includes a pre-filter (2) before the oil pump, an oil pump (3), a dehydrator (8), a primary precision filter (12), and a secondary precision filter (16) connected in sequence; A moisture on-line monitoring device (22) is connected in parallel with the pre-filter (2) before the oil pump, a dehydrating electric bypass valve (11) is connected in parallel with the dehydrator (8), and a moisture target value and a moisture over-limit value are preset in the dehydrating electric bypass valve (11); The outlet of the oil pump (3) is connected with a system pressure transmitter (6) and a system pressure gauge (4), and the system pressure gauge (4) is connected with a system pressure alarm switch (5); A primary precision filter pre-pressure transmitter (9) is arranged between the dehydrator (8) and the primary precision filter (12), and a secondary precision filter pre-pressure transmitter (13) is arranged between the primary precision filter (12) and the secondary precision filter (16); A differential pressure alarm (15) is connected in parallel with the secondary precision filter (16); The moisture on-line monitoring device (22), the system pressure transmitter (6), the primary precision filter pre-pressure transmitter (9), the secondary precision filter pre-pressure transmitter (13), and the differential pressure alarm (15) are jointly connected with a PLC controller, and the PLC controller is arranged in a control cabinet (23); The control method of the fuel oil anti-moisture monitoring system is: comparing P with A, and comparing P with B; where P is the average value P of 6 real-time moisture data, A is the preset moisture target value of the dehydrating electric bypass valve (11), and B is the moisture over-limit value; The real-time moisture data is obtained through the on-line monitoring device (22); when P < A, the dehydrating electric bypass valve (11) is opened; when P is greater than B, the dehydrating electric bypass valve (11) is closed; when A < P < B, the dehydrating electric bypass valve (11) remains in the current state unchanged; The method for judging the replacement of the filter element in the dehydrator (8) is: closing the dehydrating electric bypass valve (11), collecting the moisture on-line monitoring device (22) once every 24 hours, and replacing the filter element when any of the following conditions is met: (1) When four consecutive numbers satisfy an increasing relationship and the latest data is greater than 800, a prompt to replace the filter element is given; (2) When the latest data is greater than 1200, a prompt to replace the filter element is given; When the preset value of the system pressure alarm is greater than 2.5 MPa and the differential pressure of the secondary precision filter (16) is greater than 〇.35 MPa, the equipment alarms and stops; When the temperature displayed by the temperature transmitter (17) > 35 °C, when any one of the differential pressure values of the dehydrator (8), the primary precision filter (12), and the secondary precision filter (16) is greater than the preset alarm value, the equipment alarms and stops.

2. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, A filter element with a precision of 100 meshes is installed in the pre-filter (2) before the oil pump; the standard displacement of the oil pump (3) is 10 L / min.

3. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, The outlet of the oil pump (3) is connected with a system pressure gauge (4), and the system pressure gauge (4) is connected with a system pressure alarm switch (5); The system pressure alarm switch (5) is connected with a PLC controller.

4. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, The oil pump (3) is connected in parallel with a relief valve (19). The high-pressure inlet of the relief valve (19) is connected to the outlet of the oil pump (3), and the low-pressure return port of the relief valve (19) is connected to the inlet of the oil pump (3). The relief valve (19) is set to 2.5MPa full return.

5. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, The primary precision filter (12) contains four filter elements with a filtration accuracy of 5 μm; the secondary precision filter (16) contains one filter element with a filtration accuracy of 1 μm.

6. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, A pressure gauge (10) is provided between the dehydrator (8) and the primary precision filter (12).

7. The control method for a moisture monitoring system for fire-resistant oil according to claim 1, characterized in that, A temperature transmitter (17) is installed at the outlet of the secondary precision filter (16), and the temperature transmitter (17) is connected to the PLC controller.

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