Self-cleaning oil way filtering device of steam turbine EH oil system

Abstract

The utility model discloses a self-cleaning oil way filtering device of a steam turbine EH oil system, which comprises double filter elements connected in parallel, a differential pressure transducer connected with the filter elements, a switching valve, a backwashing pipeline and a control module, one end of the switching valve is connected with the output end of an oil pump, the other end of the switching valve is connected with the input ends of the filter elements, and the output ends of the filter elements are connected with a main oil tank. One end of the backwashing pipeline is connected with the output end of the oil pump, the other end is connected with the output end of the filter element, and the control module is electrically connected with the differential pressure sensor and the switching valve. The two independent filter elements are arranged, alternate filtering of an oil way is achieved through the switching valve, continuous oil supply of the oil way is guaranteed, and the shutdown risk of a unit is reduced; the backwashing mechanism is driven by the oil pressure difference of the system, the blocked filter element is automatically washed through reverse oil flow, external power is not needed, and the stability of the EH oil system is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of steam turbine EH oil system, specifically a self-cleaning oil circuit filtration device for steam turbine EH oil system. Background Technology

[0002] The existing 680MW thermal power unit's EH oil system is equipped with two independent pump systems, each with a capacity of 100%. Each pump consists of an AC electric oil pump, inlet and outlet filters, unloading valves, overflow valves, etc. Because this system only uses a single-stage filter element (model HC9601FDP8Z), the following problems exist in actual production: 1) The filter element is prone to clogging. A review of maintenance records shows that the EH oil pump outlet filter needs to be replaced every month for each unit. During replacement, the system needs to switch to the standby pump, posing a risk of oil pressure interruption in the EH oil system, thus affecting the safe and stable operation of the unit; 2) Manual maintenance costs are high, and because the EH oil pump outlet filter is located on top of the oil tank, there is a risk of falls during filter replacement; 3) Although the EH oil pump outlet filter is equipped with a differential pressure alarm device, it lacks a backwashing structure and has a low level of automation, which does not conform to the current trend of building smart power plants. Utility Model Content

[0003] The purpose of this invention is to provide a self-cleaning oil circuit filtration device for a steam turbine EH oil system to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a self-cleaning oil circuit filtration device for a steam turbine EH oil system, comprising: two filter elements connected in parallel, a differential pressure sensor, a switching valve, a backwashing pipeline, and a control module connected to the filter elements. One end of the switching valve is connected to the output end of the oil pump, and the other end is connected to the input end of the filter element. The output end of the filter element is connected to the oil tank. One end of the backwashing pipeline is connected to the output end of the oil pump, and the other end is connected to the output end of the filter element. The control module is electrically connected to the differential pressure sensor and the switching valve respectively.

[0005] During normal operation, the oil is filtered through the first filter element A, and the first differential pressure sensor monitors it in real time. When the differential pressure exceeds the set threshold (the set threshold is 0.69 MPa), the first switching valve closes the channel where the first filter element A is located and opens the channel where the second filter element B is located, and the oil is switched to the second filter element B. At the same time, the third switching valve and the backwash valve are opened to backwash the first filter element A using the system oil pressure, and impurities are discharged through the drain pipe. After the flushing is completed, filter element A returns to standby status, and the cycle alternates.

[0006] Compared to existing technologies, this invention features two independent filter elements, which are used to achieve alternating filtration of the oil circuit through a switching valve, ensuring continuous oil supply and reducing the risk of unit shutdown. The backwashing mechanism is driven by the system oil pressure difference, which automatically flushes the clogged filter elements through reverse oil flow, requiring no external power and improving the stability of the EH oil system.

[0007] In one embodiment of this application, the dual filter elements include a first filter element and a second filter element, the differential pressure sensor includes a first differential pressure sensor and a second differential pressure sensor, and the switching valve includes a first switching valve and a second switching valve; wherein, the first filter element and the second filter element are connected in parallel, one end of the first switching valve is connected to the output end of the first oil pump, and the other end is connected to the input end of the first filter element, the input end of the first differential pressure sensor is connected to the input end of the first filter element, the output end of the first differential pressure sensor is connected to the output end of the first filter element, the output end of the first filter element is connected to the main oil tank, one end of the second switching valve is connected to the output end of the second oil pump, and the other end is connected to the input end of the second filter element, the input end of the second differential pressure sensor is connected to the input end of the second filter element, the output end of the second differential pressure sensor is connected to the output end of the second filter element, and the output end of the second filter element and the differential pressure sensor are connected to the main oil tank.

[0008] In one embodiment of this application, the backwashing pipeline includes a third switching valve, a fourth switching valve, and a backwashing valve. One end of the third switching valve is connected to the output end of the first oil pump, and the other end is connected to the backwashing valve. One end of the fourth switching valve is connected to the output end of the second oil pump, and the other end is connected to the backwashing valve. The backwashing valve is connected to the output ends of the first filter element and the second filter element, respectively.

[0009] In one embodiment of this application, a one-way valve is also included, and the two filter elements are respectively connected to the main oil tank through the one-way valve.

[0010] In one embodiment of this application, an overflow valve is also provided between the dual filter elements and the main oil tank.

[0011] In one embodiment of this application, the control module further includes an alarm unit, which is used to send a warning signal when the filter element or system is abnormal.

[0012] In one embodiment of this application, the switching valve is a solenoid valve or a hydraulic control valve.

[0013] In one embodiment of this application, a flow meter is also provided between the oil pump and the switching valve.

[0014] In one embodiment of this application, a drain pipe is also included, which is connected to the output end of the dual filter elements to discharge the rinsed impurities from the filter elements and into the sedimentation tank.

[0015] In one embodiment of this application, the control module includes an integrated PLC or a microcontroller. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a self-cleaning oil circuit filter device for a steam turbine EH oil system provided in an embodiment of this application;

[0018] Figure Labels

[0019] 101. First oil pump; 102. Second oil pump; 200. Flow meter; 301. First switching valve; 302. Second switching valve; 401. First filter element; 402. Second filter element; 501. First differential pressure sensor; 502. Second differential pressure sensor; 601. Third switching valve; 602. Fourth switching valve; 603. Backwash valve; 700. Main oil tank; 800. Sedimentation tank; 900. Check valve; 1000. Overflow valve. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and 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 this application.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] Please see Figure 1 A self-cleaning oil circuit filtration device for a steam turbine EH oil system includes: two filter elements connected in parallel, a differential pressure sensor, a switching valve, a backwashing pipeline, and a control module connected to the filter elements. One end of the switching valve is connected to the output end of the oil pump, and the other end is connected to the input end of the filter element. The output end of the filter element is connected to the main oil tank 700. One end of the backwashing pipeline is connected to the output end of the oil pump, and the other end is connected to the output end of the filter element. The control module is electrically connected to the differential pressure sensor and the switching valve respectively.

[0025] During normal operation, the oil is filtered through the first filter element A, and the first differential pressure sensor monitors it in real time. When the differential pressure exceeds the set threshold (the set threshold is 0.69 MPa), the first switching valve closes the channel where the first filter element A is located and opens the channel where the second filter element B is located, and the oil is switched to the second filter element B. At the same time, the third switching valve and the backwash valve are opened to backwash the first filter element A using the system oil pressure, and impurities are discharged through the drain pipe. After the flushing is completed, filter element A returns to standby status, and the cycle alternates.

[0026] Compared to existing technologies, this invention features two independent filter elements, which are used to achieve alternating filtration of the oil circuit through a switching valve, ensuring continuous oil supply and reducing the risk of unit shutdown. The backwashing mechanism is driven by the system oil pressure difference, which automatically flushes the clogged filter elements through reverse oil flow, requiring no external power and improving the stability of the EH oil system.

[0027] In some embodiments, the dual filter elements include a first filter element 401 and a second filter element 402, the differential pressure sensor includes a first differential pressure sensor 501 and a second differential pressure sensor 502, and the switching valve includes a first switching valve 301 and a second switching valve 302; wherein, the first filter element 401 and the second filter element 402 are connected in parallel, one end of the first switching valve 301 is connected to the output end of the first oil pump 101, and the other end is connected to the input end of the first filter element 401, and the input end of the first differential pressure sensor 501 is connected to the input end of the first filter element 401. The output end of the differential pressure sensor 501 is connected to the output end of the first filter element 401, and the output end of the first filter element 401 is connected to the main oil tank 700. One end of the second switching valve 302 is connected to the output end of the second oil pump 102, and the other end is connected to the input end of the second filter element 402. The input end of the second differential pressure sensor 502 is connected to the input end of the second filter element 402, and the output end of the second differential pressure sensor 502 is connected to the output end of the second filter element 402. The output end of the second filter element 402 and the differential pressure sensor are connected to the main oil tank 700.

[0028] Two independent filter elements are installed, with the filter element material being a multi-layer stainless steel sintered mesh and a precision of ≤5μm; the oil circuit is alternately filtered through a switching valve to ensure the continuous operation of the EH oil system and avoid unit shutdowns caused by filter element clogging.

[0029] In some embodiments, the backwashing pipeline includes a third switching valve 601, a fourth switching valve 602, and a backwashing valve 603. One end of the third switching valve 601 is connected to the output end of the first oil pump 101, and the other end is connected to the backwashing valve 603. One end of the fourth switching valve 602 is connected to the output end of the second oil pump 102, and the other end is connected to the backwashing valve 603. The backwashing valve 603 is connected to the output ends of the first filter element 401 and the second filter element 402, respectively. The backwashing pipeline is connected to the filter element outlet end and utilizes oil pressure difference to drive backwashing. The reverse oil flow automatically flushes clogged filter elements without external power. This extends filter element life, reduces maintenance workload, and improves the stability of the EH oil system.

[0030] In some embodiments, a one-way valve 900 is also included, and the two filter elements are respectively connected to the main oil tank 700 through the one-way valve 900. The one-way valve 900 is provided to prevent oil backflow.

[0031] In some embodiments, an overflow valve 1000 is also provided between the dual filter elements and the main oil tank 700. The overflow valve 1000 opens at 16.4-16.6 MPa, realizing intelligent control of oil circuit filtration.

[0032] In some embodiments, the control module further includes an alarm unit, which sends a warning signal when the filter element or system malfunctions. By combining a differential pressure sensor and an alarm unit, remote monitoring of the filter element's status is achieved.

[0033] In some embodiments, the switching valve is a solenoid valve or a hydraulically controlled valve. Using a solenoid valve or hydraulically controlled valve results in a response time of ≤1 second, improving the self-cleaning efficiency of the turbine oil circuit.

[0034] In some embodiments, a flow meter 200 is also provided between the oil pump and the switching valve, enabling intelligent monitoring of the oil circuit status.

[0035] In some embodiments, a drain pipe is also included, which is connected to the output end of the dual filter elements to discharge the rinsed impurities from the filter elements and into the settling oil tank 800. The rinsed impurities are discharged into the settling oil tank 800 through an independent drain pipe, and then the filtered EH oil is returned to the oil tank through an external oil filter to avoid secondary pollution.

[0036] In some embodiments, the control module includes an integrated PLC or microcontroller. Intelligent monitoring reduces the risk of oil contamination and improves turbine control accuracy.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-cleaning oil passage filter device for a steam turbine EH oil system, characterized by, The application relates to a double-filter core parallel connection type oil filter, which comprises differential pressure sensors, switching valves, backwashing pipelines and a control module connected with filter cores, one end of the switching valve is connected with an output end of an oil pump, the other end is connected with an input end of the filter core, an output end of the filter core is connected with a main oil tank, one end of the backwashing pipeline is connected with the output end of the oil pump, the other end is connected with an output end of the filter core, and the control module is electrically connected with the differential pressure sensors and the switching valves. The double-filter core comprises a first filter core and a second filter core, the differential pressure sensors comprise a first differential pressure sensor and a second differential pressure sensor, and the switching valves comprise a first switching valve and a second switching valve; wherein the first filter core and the second filter core are connected in parallel, one end of the first switching valve is connected with an output end of a first oil pump, the other end is connected with an input end of the first filter core, an input end of the first differential pressure sensor is connected with the input end of the first filter core, an output end of the first differential pressure sensor is connected with an output end of the first filter core, the output end of the first filter core is connected with the main oil tank, one end of the second switching valve is connected with an output end of a second oil pump, the other end is connected with an input end of the second filter core, an input end of the second differential pressure sensor is connected with the input end of the second filter core, an output end of the second differential pressure sensor is connected with an output end of the second filter core, and the output end of the second filter core is connected with the main oil tank.

2. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, The backwashing pipeline comprises a third switching valve, a fourth switching valve and a backwashing valve, wherein one end of the third switching valve is connected with the output end of the first oil pump, the other end is connected with the backwashing valve; one end of the fourth switching valve is connected with the output end of the second oil pump, the other end is connected with the backwashing valve; and the output ends of the first filter core and the second filter core are connected with the backwashing valve.

3. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 2, characterized by, The double-filter core is connected with the main oil tank through a one-way valve.

4. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, An overflow valve is arranged between the double-filter core and the main oil tank.

5. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, The control module further comprises an alarm unit which is used for sending a pre-warning signal when the filter core or the system is abnormal.

6. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, The switching valve is an electromagnetic valve or a liquid control valve.

7. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, A flowmeter is arranged between the oil pump and the switching valve.

8. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, A blowdown pipeline is arranged, and the blowdown pipeline is connected with the output ends of the double-filter cores and is used for discharging impurities from the filter core into a sediment oil tank after washing.

9. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, The control module comprises an integrated PLC or a microcontroller.

10. The self-cleaning oil passage filter device of a steam turbine EH oil system according to claim 1, characterized by, ​

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