A hydroelectric power hydraulic oil quality online and offline monitoring and alarm system and its working method

Abstract

The present invention discloses an online monitoring and alarm system for the quality of hydropower hydraulic oil and its working method, which belongs to the field of hydropower station operation and maintenance technology. It includes a control oil supply sampling branch pipe, a power oil supply sampling branch pipe, a sampling main pipe, a monitoring branch pipe, a flushing bypass branch pipe, a particle size sensor, a sampling branch pipe and an analysis and control device; it can effectively realize online monitoring and offline sampling of the power oil and control oil of the speed control oil system, and send the monitoring results to the analysis and control device in time. The analysis and control device can alarm according to the oil cleanliness exceeding the limit and notify the operating personnel to perform maintenance in time. By setting a sampling main pipe between the monitoring oil pipeline and the pressure oil tank drain pipe, the present invention can obtain comprehensive and representative oil samples, improve the accuracy of the monitoring values, and effectively prevent accidental shutdowns due to unqualified oil, ensuring the safe and stable operation of the turbine unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydropower station operation and maintenance, and in particular relates to an on-line monitoring and alarm system for the quality of hydropower hydraulic oil and a working method thereof. Background Art

[0002] The main users of hydropower hydraulic systems are high-precision components such as solenoid valves and servo valves. These components have extremely high requirements for oil quality. The regulations on the requirements for governor oil quality mainly include: GB / T 14541-2005 "Guidelines for Maintenance and Management of Mineral Turbine Oils for Power Plants", DL / T 1975-2019 "Maintenance Regulations for Oil Used in Turbine Control Systems" and NB / T 42095-2016 "Basic Technical Conditions for High-Pressure Governors of Small Hydropower Units". The regulations stipulate that the oil particle size grade must be below NAS7 and have relatively strict regulations on sampling points.

[0003] In recent years, numerous hydropower units, including some of the largest, have experienced unexpected shutdowns due to servo or solenoid valve jams caused by oil quality issues. These jams have also had a significant impact on the power grid. Subsequent analysis of these incidents revealed that the jams were caused by substandard oil quality or inadequate monitoring of oil particle deterioration. Oil quality monitoring, sampling, and oversight have been plagued by issues such as unrepresentative sampling points, long sampling intervals, and infrequent sampling, as well as the inability to dynamically monitor oil quality deterioration. Summary of the Invention

[0004] In order to solve the above-mentioned existing problems, the purpose of the present invention is to provide an online monitoring and alarm system for the quality of hydroelectric power hydraulic oil and its working method, which can realize online monitoring and offline sampling of power oil supply and return and control oil supply and return, prevent accidental shutdown due to unqualified oil, and ensure the safe and stable operation of the unit.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention discloses an online monitoring and alarm system for the quality of hydroelectric power hydraulic oil, comprising a control oil supply sampling branch pipe, a power oil supply sampling branch pipe, a sampling main pipe, a monitoring branch pipe, a flushing bypass branch pipe, a particle size sensor, a sampling branch pipe, and an analysis and control device;

[0007] One end of the control oil supply sampling branch pipe is connected to the control oil supply pipe, and the other end is connected to the inlet end of the sampling main pipe. The control oil supply sampling branch pipe is provided with a control oil supply sampling branch pipe stop valve; one end of the power oil supply sampling branch pipe is connected to the power oil supply pipe, and the other end is connected to the inlet end of the sampling main pipe. The power oil supply sampling branch pipe is provided with a power oil supply sampling branch pipe stop valve; the monitoring branch pipe and the flushing bypass branch pipe are arranged in parallel on the sampling main pipe, the monitoring branch pipe is provided with a particle size sensor, and the flushing bypass branch pipe is provided with a flushing bypass branch stop valve; the outlet end of the sampling main pipe is connected to the pressure oil tank drain pipe, and the sampling main pipe is provided with a sampling main pipe stop valve; the sampling main pipe is connected to an offline sampling pipe, and the offline sampling pipe is provided with an offline sampling pipe stop valve;

[0008] The control oil supply sampling branch pipe stop valve, the power oil supply sampling branch pipe stop valve, the particle size sensor, the flushing bypass branch pipe stop valve and the sampling main pipe stop valve are respectively connected to the analysis and control device.

[0009] Preferably, an adjustable orifice plate is provided at the inlet of the monitoring branch pipe.

[0010] Further preferably, the diameter of the adjustable orifice plate is adjustable from 5 to 10 mm.

[0011] Preferably, the control oil supply sampling branch pipe, the power oil supply sampling branch pipe and the sampling main pipe are connected through a three-way valve.

[0012] Preferably, the inlet ends of the monitoring branch pipe and the flushing bypass branch pipe are connected to the sampling main pipe through a first bypass three-way valve, and the outlet ends of the monitoring branch pipe and the flushing bypass branch pipe are connected to the sampling main pipe through a second bypass three-way valve.

[0013] Preferably, the offline sampling tube is connected to the sampling main tube through an offline sampling tube three-way valve, and a pressureless funnel is provided on the offline sampling tube.

[0014] The working method of the above-mentioned hydroelectric power hydraulic oil quality online and offline monitoring and alarm system disclosed in the present invention includes:

[0015] Power oil offline sampling: open the power oil supply sampling branch pipe stop valve, flushing bypass branch pipe stop valve and offline sampling pipe stop valve, close the control oil supply sampling branch pipe stop valve and sampling main pipe stop valve, and the power oil will flow from the power oil supply pipe through the power oil supply sampling branch pipe, sampling main pipe, flushing bypass branch pipe and offline sampling pipe into the sampling container in sequence;

[0016] Control oil offline sampling: open the control oil supply sampling branch pipe stop valve, flushing bypass branch pipe stop valve and offline sampling pipe stop valve, close the power oil supply sampling branch pipe stop valve and sampling main pipe stop valve, and the power oil will enter the sampling container from the control oil supply pipe through the control oil supply sampling branch pipe, sampling main pipe, flushing bypass branch pipe and offline sampling pipe in sequence;

[0017] Power oil online monitoring: Open the shutoff valves of the power oil supply sampling branch pipe and the sampling main pipe, and close the shutoff valves of the control oil supply sampling branch pipe, the flushing bypass branch pipe, and the offline sampling pipe. The power oil flows from the power oil supply pipe through the power oil supply sampling branch pipe, the sampling main pipe, and the particle size sensor, and then into the pressure oil tank drain pipe. The particle size sensor monitors the cleanliness of the power oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a power oil particle size contamination alarm is issued.

[0018] Online monitoring of control oil: open the control oil supply sampling branch pipe stop valve and the sampling main pipe stop valve, close the power oil supply sampling branch pipe stop valve, the flushing bypass branch pipe stop valve and the offline sampling pipe stop valve, and the control oil will flow from the control oil supply pipe through the control oil supply sampling branch pipe, the sampling main pipe, the particle size sensor and then into the pressure oil tank drain pipe; the particle size sensor monitors the oil cleanliness of the control oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a control oil particle size contamination alarm will be issued.

[0019] Preferably, before performing offline sampling of the power oil and the control oil, flushing is performed with a flushing oil volume of 5 times or more than the sampling volume.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] The present invention discloses an online monitoring and alarm system for hydroelectric power hydraulic oil quality. This system effectively implements online monitoring and offline sampling of the power oil and control oil in the speed control oil system, and promptly transmits the monitoring results to an analysis and control device. The analysis and control device can then issue an alarm based on oil cleanliness exceeding limits, promptly notifying operators to perform maintenance. By providing a sampling main pipe between the monitoring oil pipeline and the pressure oil tank drain pipe, the present invention can obtain comprehensive and representative oil samples, improving the accuracy of monitoring values. It can also effectively prevent accidental shutdowns caused by unqualified oil and ensure the safe and stable operation of the turbine unit.

[0022] The working method of the above-mentioned hydroelectric power hydraulic oil quality online monitoring and alarm system disclosed in the present invention has a high degree of automation, can obtain comprehensive and representative oil samples, saves manpower and material costs, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the hydroelectric power hydraulic oil quality online and offline monitoring and alarm system of the present invention;

[0024] Figure 2 This is a classification table for oil cleanliness.

[0025] In the figure: 1 is the control oil supply sampling branch pipe, 2 is the control oil supply sampling branch pipe stop valve, 3 is the power oil supply sampling branch pipe, 4 is the power oil supply sampling branch pipe stop valve, 5 is the sampling main pipe, 6 is the monitoring branch pipe, 7 is the flushing bypass branch pipe, 8 is the particle size sensor, 9 is the adjustable flow orifice plate, 10 is the flushing bypass branch pipe stop valve, 11 is the first bypass three-way valve, 12 is the second bypass three-way valve, 13 is the offline sampling pipe three-way valve, 14 is the offline sampling pipe stop valve, 15 is the pressureless funnel, 16 is the sampling main pipe stop valve, 17 is the power oil supply pipe, 18 is the control oil supply pipe, 19 is the pressure oil tank drain pipe, 20 is the pressure oil tank, and 21 is the return oil tank. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it:

[0027] Hydraulic oil in hydropower stations is primarily used in speed governor control systems and inlet shut-off valve control. This oil source provides the power for the speed governor control system and is primarily divided into two types: control oil and power oil. The control oil, after amplifying the electrical signal through the electro-hydraulic servo system into a hydraulic signal, primarily provides driving power to the main pressure regulating valve based on the control signal. The power oil, after amplification by the main pressure regulating valve, provides power to the servo, which drives the guide vanes to open and close, thereby controlling the unit's speed and load. The speed governor hydraulic oil typically has a pressure oil tank 20 and a return oil tank 21 as primary storage or energy storage devices. The oil pressure control system primarily consists of electrical switch nodes and a controller, responsible for starting and stopping the pressurized oil pump. Key users of control oil include servo valves, emergency stop solenoid valves, sectional solenoid valves, emergency solenoid valves, switching valves, and mechanical overspeed devices. Key users of power oil include the main pressure regulating valve, emergency pressure regulating valve, servo, and sectional shut-off valves.

[0028] Hydraulic oil in large and high-head hydropower station units, including cylinder valves or butterfly valves, is collectively referred to as inlet stop valves. Inlet stop valves lack adjustment capabilities and serve only to shut off water flow during emergency or normal shutdowns. The inlet stop valve primarily consists of a return oil tank and a pressure oil tank to power the valve's opening and closing. The oil pressure control system, comprised of electrical switch nodes and a controller, controls the start and stop of the pressurized oil pump. The inlet stop valve is primarily divided into power oil and control oil. Power oil users primarily include pressure regulating valves and servomotors, while control oil users primarily include switching valves and on / off solenoid valves.

[0029] like Figure 1 The present invention provides an online monitoring and alarm system for the quality of hydropower hydraulic oil, comprising a control oil supply sampling branch pipe 1, a power oil supply sampling branch pipe 3, a sampling main pipe 5, a monitoring branch pipe 6, a flushing bypass branch pipe 7, a particle size sensor 8, a sampling branch pipe, and an analysis and control device.

[0030] One end of the control oil supply sampling branch pipe 1 is connected to the control oil supply pipe 18, and the other end is connected to the inlet end of the sampling main pipe 5. The control oil supply sampling branch pipe 1 is provided with a control oil supply sampling branch pipe stop valve 2; one end of the power oil supply sampling branch pipe 3 is connected to the power oil supply pipe 17, and the other end is connected to the inlet end of the sampling main pipe 5. The power oil supply sampling branch pipe 3 is provided with a power oil supply sampling branch pipe stop valve 4; the monitoring branch pipe 6 and the flushing bypass branch pipe 7 are arranged in parallel on the sampling main pipe 5, the monitoring branch pipe 6 is provided with a particle size sensor 8, and the flushing bypass branch pipe 7 is provided with a flushing bypass branch pipe stop valve 10; the outlet end of the sampling main pipe 5 is connected to the pressure oil tank drain pipe 19, and the sampling main pipe 5 is provided with a sampling main pipe stop valve 16; the sampling main pipe 5 is connected to an offline sampling pipe, and the offline sampling pipe is provided with an offline sampling pipe stop valve 14;

[0031] The control oil supply sampling branch pipe stop valve 2, the power oil supply sampling branch pipe stop valve 4, the particle size sensor 8, the flushing bypass branch pipe stop valve 10 and the sampling main pipe stop valve 16 are respectively connected to the analysis and control device.

[0032] In a preferred embodiment of the present invention, an adjustable orifice plate 9 is provided at the inlet of the monitoring branch pipe 6. Preferably, the diameter of the adjustable orifice plate 9 is adjustable from 5 to 10 mm.

[0033] In a preferred embodiment of the present invention, the control oil supply sampling branch pipe 1, the power oil supply sampling branch pipe 3 and the sampling main pipe 5 are connected through a three-way valve.

[0034] In a preferred embodiment of the present invention, the inlet ends of the monitoring branch pipe 6 and the flushing bypass branch pipe 7 are connected to the sampling main pipe 5 through a first bypass three-way valve 11, and the outlet ends of the monitoring branch pipe 6 and the flushing bypass branch pipe 7 are connected to the sampling main pipe 5 through a second bypass three-way valve 12.

[0035] In a preferred embodiment of the present invention, the offline sampling tube is connected to the sampling main tube 5 through an offline sampling tube three-way valve 13 , and a pressureless funnel 15 is provided on the offline sampling tube.

[0036] The working method of the above-mentioned hydroelectric power hydraulic oil quality online and offline monitoring and alarm system includes:

[0037] Power oil offline sampling: Open the power oil supply sampling branch pipe stop valve 4, the flushing bypass branch pipe stop valve 10 and the offline sampling pipe stop valve 14, close the control oil supply sampling branch pipe stop valve 2 and the sampling main pipe stop valve 16, and the power oil will enter the sampling container from the power oil supply pipe 17 through the power oil supply sampling branch pipe 3, the sampling main pipe 5, the flushing bypass branch pipe 7 and the offline sampling pipe in sequence;

[0038] Control oil offline sampling: Open the control oil supply sampling branch pipe stop valve 2, the flushing bypass branch pipe stop valve 10 and the offline sampling pipe stop valve 14, close the power oil supply sampling branch pipe stop valve 4 and the sampling main pipe stop valve 16, and the power oil will enter the sampling container from the control oil supply pipe 18 through the control oil supply sampling branch pipe 1, the sampling main pipe 5, the flushing bypass branch pipe 7 and the offline sampling pipe in sequence;

[0039] Power oil online monitoring: Open the power oil supply sampling branch pipe shutoff valve 4 and the sampling main pipe shutoff valve 16, and close the control oil supply sampling branch pipe shutoff valve 2, the flushing bypass branch pipe shutoff valve 10, and the offline sampling pipe shutoff valve 14. The power oil flows from the power oil supply pipe 17 through the power oil supply sampling branch pipe 3, the sampling main pipe 5, and the particle size sensor 8, and then into the pressure oil tank drain pipe 19. The particle size sensor 8 monitors the cleanliness of the power oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a power oil particle size contamination alarm is issued.

[0040] Online monitoring of control oil: open the control oil supply sampling branch pipe stop valve 2 and the sampling main pipe stop valve 16, close the power oil supply sampling branch pipe stop valve 4, the flushing bypass branch pipe stop valve 10 and the offline sampling pipe stop valve 14, and the control oil will enter the pressure oil tank drain pipe 19 from the control oil supply pipe 18 through the control oil supply sampling branch pipe 1, the sampling main pipe 5, the particle size sensor 8 in sequence; the particle size sensor 8 monitors the oil cleanliness of the control oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a control oil particle size contamination alarm will be issued.

[0041] Before performing offline sampling of power oil and control oil, flush with flushing oil of more than 5 times the sampling volume, and then drain into the pressureless funnel 15 to be recovered into the waste oil tank.

[0042] The present invention will be further explained below with a specific embodiment:

[0043] This embodiment of the analysis and control device includes a controller, an AI board, a DO board, relays KC1, KC2, and KC3, and cables for signal transmission. Particle size sensor 8 continuously transmits particle size readings to the AI ​​board. The controller then logically determines the oil cleanliness level, provides level 1 and level 2 particle size alarms, and issues a particle size sensor fault alarm.

[0044] Specific connection process: granularity sensor 8 is connected to the AI ​​board. After logical judgment, the DO board controls the KC1 relay and sends the sensor fault signal to the LCU through the corresponding node of the KC1 relay; the DO board controls the KC2 relay and sends the granularity level 1 alarm signal to the LCU through the corresponding node of the KC2 relay; the DO board controls the KC3 relay and sends the granularity level 2 alarm signal to the LCU through the corresponding node of the KC3 relay. Specific logic of granularity alarm: such as Figure 2 According to the NAS grading standard, oil cleanliness is divided into 14 levels, with Level 00 being the highest and Level 12 being the lowest, indicating a higher degree of contamination. Oil cleanliness levels are represented by L, and the increase in cleanliness is represented by ΔL. Level 1 alarms are: L ≥ Level 8 or (ΔL ≥ 15% and 30 days); Level 2 alarms are: L ≥ Level 9 or (ΔL ≥ 25% and 30 days).

[0045] The above description is merely an embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention, or equivalent structures or equivalent process transformations made using the contents of the present invention's description and drawings, or direct or indirect applications in other related technical fields, should all be covered by the scope of protection of the present invention.

Claims

1. A hydropower hydraulic oil quality online and offline monitoring and alarm system, characterized in that: It includes a control oil supply sampling branch pipe (1), a power oil supply sampling branch pipe (3), a sampling main pipe (5), a monitoring branch pipe (6), a flushing bypass branch pipe (7), a particle size sensor (8), a sampling branch pipe and an analysis and control device; One end of the control oil supply sampling branch pipe (1) is connected to the control oil supply pipe (18), and the other end is connected to the inlet end of the sampling main pipe (5). The control oil supply sampling branch pipe (1) is provided with a control oil supply sampling branch pipe stop valve (2); one end of the power oil supply sampling branch pipe (3) is connected to the power oil supply pipe (17), and the other end is connected to the inlet end of the sampling main pipe (5). The power oil supply sampling branch pipe (3) is provided with a power oil supply sampling branch pipe stop valve (4); the monitoring branch The pipe (6) and the flushing bypass branch pipe (7) are arranged in parallel on the sampling main pipe (5); the monitoring branch pipe (6) is provided with a particle size sensor (8), and the flushing bypass branch pipe (7) is provided with a flushing bypass branch stop valve (10); the outlet end of the sampling main pipe (5) is connected to the pressure oil tank oil discharge pipe (19), and the sampling main pipe (5) is provided with a sampling main pipe stop valve (16); the sampling main pipe (5) is connected to an offline sampling pipe, and the offline sampling pipe is provided with an offline sampling pipe stop valve (14); The control oil supply sampling branch pipe stop valve (2), the power oil supply sampling branch pipe stop valve (4), the particle size sensor (8), the flushing bypass branch pipe stop valve (10) and the sampling main pipe stop valve (16) are respectively connected to the analysis and control device.

2. The hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 1 is characterized in that: An adjustable orifice plate (9) is provided at the inlet of the monitoring branch pipe (6).

3. The hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 2 is characterized in that: The diameter of the adjustable orifice plate (9) is adjustable within the range of 5 to 10 mm.

4. The hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 1 is characterized in that: The control oil supply sampling branch pipe (1), the power oil supply sampling branch pipe (3) and the sampling main pipe (5) are connected via a three-way valve.

5. The hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 1 is characterized in that: The inlet ends of the monitoring branch pipe (6) and the flushing bypass branch pipe (7) are connected to the sampling main pipe (5) through a first bypass three-way valve (11), and the outlet ends of the monitoring branch pipe (6) and the flushing bypass branch pipe (7) are connected to the sampling main pipe (5) through a second bypass three-way valve (12).

6. The hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 1 is characterized in that: The offline sampling tube is connected to the sampling main tube (5) through an offline sampling tube three-way valve (13), and a pressureless funnel (15) is provided on the offline sampling tube.

7. The operating method of the hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claims 1 to 6, characterized in that: include: Power oil offline sampling: open the power oil supply sampling branch pipe stop valve (4), the flushing bypass branch pipe stop valve (10) and the offline sampling pipe stop valve (14), close the control oil supply sampling branch pipe stop valve (2) and the sampling main pipe stop valve (16), and the power oil flows from the power oil supply pipe (17) through the power oil supply sampling branch pipe (3), the sampling main pipe (5), the flushing bypass branch pipe (7) and the offline sampling pipe into the sampling container in sequence; Control oil offline sampling: open the control oil supply sampling branch pipe stop valve (2), the flushing bypass branch pipe stop valve (10) and the offline sampling pipe stop valve (14), close the power oil supply sampling branch pipe stop valve (4) and the sampling main pipe stop valve (16), and the power oil enters the sampling container from the control oil supply pipe (18) through the control oil supply sampling branch pipe (1), the sampling main pipe (5), the flushing bypass branch pipe (7) and the offline sampling pipe in sequence; Power oil online monitoring: open the power oil supply sampling branch pipe stop valve (4) and the sampling main pipe stop valve (16), close the control oil supply sampling branch pipe stop valve (2), the flushing bypass branch pipe stop valve (10) and the offline sampling pipe stop valve (14), and the power oil flows from the power oil supply pipe (17) through the power oil supply sampling branch pipe (3), the sampling main pipe (5), the particle size sensor (8) and then into the pressure oil tank drain pipe (19); the particle size sensor (8) monitors the oil cleanliness of the power oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a power oil particle size pollution alarm is issued; Online monitoring of control oil: open the control oil supply sampling branch pipe stop valve (2) and the sampling main pipe stop valve (16), close the power oil supply sampling branch pipe stop valve (4), the flushing bypass branch pipe stop valve (10) and the offline sampling pipe stop valve (14), and the control oil flows from the control oil supply pipe (18) through the control oil supply sampling branch pipe (1), the sampling main pipe (5), the particle size sensor (8) and then into the pressure oil tank drain pipe (19); the particle size sensor (8) monitors the oil cleanliness of the control oil and sends the monitored value to the analysis and control device for comparison with the preset value. When the monitored value exceeds the preset value, a control oil particle size pollution alarm is issued.

8. The operating method of the hydroelectric power hydraulic oil quality online and offline monitoring and alarm system according to claim 7, characterized in that: Before performing offline sampling of power oil and control oil, flush with flushing oil of more than 5 times the sampling volume.

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