Water-turbine generator set derivation oil groove oil water mixing monitoring method

Abstract

A water-turbine generator set pushing and guiding oil groove oil water mixing monitoring method comprises a first water content detection device installed on a pushing and guiding oil groove outlet pipeline and a second water content detection device installed on a pushing and guiding oil groove inlet pipeline. The water content difference between the second water content detection device and the first water content detection device is used for judging and deducing the oil tank water leakage degree. Sensitivity and accuracy of oil-water mixing monitoring of the oil tank can be greatly improved, an alarm signal can be sent in time at the initial stage of water leakage, measures can be taken in time to isolate fault equipment, and accident expansion is avoided.

Description

[0001] The present invention is a divisional application of "Device and method for monitoring oil-water mixing in the oil tank of a vertical-shaft semi-umbrella-type hydro-turbine generator set" (application number: 2023102787434; application date: 2023-03-21). Technical Field

[0002] The invention belongs to the technical field of monitoring oil-water mixing in a derived oil tank of a hydro-generator set, and in particular relates to a method for monitoring oil-water mixing in a derived oil tank of a hydro-generator set. Background Art

[0003] Vertical shaft and semi-umbrella type hydro-turbine generator sets are equipped with upper guide, lower guide, thrust bearing and other bearings from top to bottom. The thrust bearing is arranged under the generator rotor, and needs to bear the weight of the rotating part of the entire hydro-turbine generator set and the axial water thrust acting on the runner. As a key component of the hydro-turbine generator set, it is particularly important to keep it well cooled and lubricated. Therefore, a guide oil tank is arranged under the generator rotor to immerse the thrust bearing and its contact surface with the rotating part in oil; at the same time, an external water cooler is arranged to extract the oil in the guide oil tank and cool it before re-entering the oil tank for circulation.

[0004] In order to ensure the safe operation of the thrust bearing, it is also very important to monitor the oil quality in the oil tank. Hydropower plants usually use water as a cooling medium. The most common problem is that water enters the oil tank, causing the oil quality to deteriorate, thereby damaging the bearing. Therefore, a set of timely and accurate methods to monitor whether water has entered the oil tank is needed.

[0005] The current monitoring method is to install a moisture detection sensor in the oil tank. However, when the moisture detection sensor reaches the alarm threshold, the amount of water seepage in the oil tank is already very serious. Therefore, the current monitoring method cannot detect water seepage in time and the response is not timely. The alarm signal can only be issued when the water content (oil mixed with water) in the entire oil tank reaches a certain value. It is very lagging and insensitive, and the problem cannot be discovered as early as possible. Summary of the invention

[0006] In view of the technical problems existing in the background technology, the method for monitoring oil-water mixing in the oil tank of a hydro-turbine generator set provided by the present invention can greatly improve the sensitivity and accuracy of oil-water mixing monitoring in the oil tank, can promptly issue an alarm signal at the early stage of water leakage, and take timely measures to isolate faulty equipment to avoid the expansion of accidents.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve: A method for monitoring oil-water mixing in a derivation oil tank of a hydro-generator set, using a derivation oil tank oil-water mixing monitoring device, the derivation oil tank oil-water mixing monitoring device comprising a first water content detection device installed on the derivation oil tank outlet pipe, and a second water content detection device installed on the derivation oil tank inlet pipe, the water content difference between the second water content detection device and the first water content detection device is used to judge the degree of water leakage in the derivation oil tank; The first water content detection device comprises a first U-shaped tube and a first pressure reducing valve, and the second water content detection device comprises a second U-shaped tube and a second pressure reducing valve; The first water content detection device and the second water content detection device are both water content detection components, the water content detection component comprises a transparent box, an iodine tungsten lamp is installed on one side of the transparent box, a photovoltaic panel is installed on the other side of the transparent box, the iodine tungsten lamp and the photovoltaic panel are arranged oppositely, and the photovoltaic panel is connected in series with an ammeter and an indicating device to form an electrical circuit; The monitoring methods are: Step 1: start the circulating oil pump on the outlet pipeline of the derivation oil tank, adjust the size of the first pressure reducing valve and the second pressure reducing valve, so that the oil fills the transparent box and the oil in the transparent box is not disturbed; the first U-shaped tube and the second U-shaped tube are used to introduce less oil into the transparent box, and the first pressure reducing valve and the second pressure reducing valve are used to prevent the oil in the transparent box from flowing too fast and causing bubbles; Step 2: Turn on the iodine tungsten lamp, and the photovoltaic panel will generate direct current when receiving light. When the oil does not contain water, the direct current is a stable value; Step three, when the water from the cooler enters the oil pipe, the mixture of oil and water will appear milky white, which will block the light transmittance of the oil, thereby affecting the power generation of the photovoltaic panel. When the current difference detected by the first water content detection component and the second water content detection component is greater than the threshold value, it proves that the water from the cooler has entered the oil pipe.

[0008] Preferably, the first U-shaped tube is connected in parallel to the outlet pipe, and a first pressure reducing valve and a first water content detection component are installed on the first U-shaped tube; one end of the second U-shaped tube is connected to the inlet pipe, and the other end is connected to the derivation oil tank, and a second pressure reducing valve and a second water content detection component are installed on the second U-shaped tube.

[0009] Preferably, the first moisture content detection component and the second moisture content detection component have the same structure and are both moisture content detection components. The moisture content detection component includes a transparent box, an iodine tungsten lamp is installed on one side of the transparent box, and a photovoltaic panel is installed on the other side of the transparent box. The iodine tungsten lamp and the photovoltaic panel are arranged relative to each other, and the photovoltaic panel is connected in series with an ammeter and an indicating device to form an electrical circuit.

[0010] Preferably, the transparent box is a square box, and other surfaces of the transparent box are provided with shading plates, and the other surfaces are the other four surfaces except the iodine tungsten lamp and the photovoltaic panel.

[0011] Preferably, the indicating device is a fan or a lamp.

[0012] Preferably, the ammeters of the first water content detection component and the second water content detection component are electrically connected to an analog quantity processing module, and the analog quantity processing module is used to calculate the current values ​​of the two ammeters and the difference between the two ammeters.

[0013] Preferably, the first pressure reducing valve is located at the process rear end of the first water content detecting component, and the second pressure reducing valve is located at the process rear end of the second water content detecting component.

[0014] Preferably, a filter is provided on the inlet pipe.

[0015] The present invention can achieve the following beneficial effects: The present invention monitors the water content before and after entering the cooler, thereby monitoring whether the oil pipe is leaking. Because it is deduced that the water entering the oil tank is most likely from the cooler. After the technical improvement of the present invention, the detection sensitivity is greatly improved, and when a fault occurs, the water inlet fault can be quickly detected. The sensitivity and accuracy of monitoring oil mixed with water in the oil tank can be greatly improved, and an alarm signal can be issued in time at the early stage of water leakage, and measures can be taken in time to isolate the faulty equipment to avoid the expansion of the accident.

[0016] The present invention can solve the problem of inaccurate sampling of the monitoring device, can timely find the leakage position causing the oil in the oil tank to mix with water, and can take isolation measures in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a system diagram of the present invention; Figure 2 The working principle diagram of the water content detection member of the present invention; Figure 3 It is a diagram for deriving the working principle of the oil tank in the prior art; Figure 4 A curve diagram showing the change between the current and time of the first water content detection device and the second water content detection device under normal conditions of the present invention; Figure 5 It is a curve diagram of the change between the current and time of the first water content detection device and the second water content detection device under water inflow condition of the present invention.

[0018] In the figure: derivation oil tank 1, cooler 2, oil pump 3, first water content detection device 4, first U-shaped tube 401, first pressure reducing valve 402, second water content detection device 5, second U-shaped tube 501, second pressure reducing valve 502, water content detection part 6, transparent box 601, iodine tungsten lamp 602, photovoltaic panel 603, filter 7, analog processing module 8, traditional water content detection sensor 9. DETAILED DESCRIPTION Embodiment 1: The preferred solution is Figure 1 to Figure 2 As shown, a method for monitoring oil-water mixing in the derivation oil tank of a hydro-turbine generator set adopts a derivation oil tank oil-water mixing monitoring device, which includes a first water content detection device 4 installed on the outlet pipe of the derivation oil tank 1, and a second water content detection device 5 installed on the inlet pipe of the derivation oil tank 1. The water content difference between the second water content detection device 5 and the first water content detection device 4 is used to judge the degree of water leakage in the derivation oil tank 1. The present invention transfers the water content detection device to the oil pipe. Since the cross-sectional area of ​​the oil pipe is much smaller than the cross-sectional area of ​​the derivation oil tank 1, the water content detection is more sensitive. In addition, the monitoring principle of the present invention is: monitor the water content before and after entering the cooler, so as to monitor whether the oil pipe is leaking. Because the water in the derivation oil tank is most likely to come from the cooler. After the technical improvement of the present invention, the detection sensitivity is greatly improved, and when a fault occurs, the water inlet fault can be quickly monitored. Furthermore, the area detected by the conventional water content detection sensor is limited to the area where the sensor probe contacts the oil. When the water content is low, the water content cannot be detected quickly. Therefore, the present invention proposes an improved solution for water content detection: The first water content detection device 4 includes a first U-shaped tube 401, which is connected in parallel to the outlet pipe, and a first pressure reducing valve 402 and a first water content detection member are installed on the first U-shaped tube 401; the second water content detection device 5 includes a second U-shaped tube 501, one end of the second U-shaped tube 501 is connected to the inlet pipe, and the other end is connected to the derivation oil tank 1, and a second pressure reducing valve 502 and a second water content detection member are installed on the second U-shaped tube 501. The first water content detection member and the second water content detection member have the same structure, both of which are water content detection members 6, and the water content detection member 6 includes a transparent box 601, a tungsten iodine lamp 602 is installed on one side of the transparent box 601, and a photovoltaic panel 603 is installed on the other side of the transparent box 601, the tungsten iodine lamp 602 and the photovoltaic panel 603 are arranged relative to each other, and the photovoltaic panel 603 is connected in series with the ammeter and the indicating device to form an electrical circuit.

[0019] The photovoltaic panel 603 is arranged opposite to the iodine tungsten lamp 602, and the illuminated area is larger than the range of the traditional water content detection sensor. When the oil contains water, a milky white liquid will be formed, and the milky white liquid will block the light, thereby causing the current to change. The current change value is used to monitor the water content, which greatly improves the sensitivity of the detection. In order to avoid the interference of sunlight on the detection result, the present invention adds a sunshade to isolate sunlight or other light. Specifically, the transparent box 601 is a square box, and the other surfaces of the transparent box 601 are provided with sunshades, and the other surfaces are the other four surfaces except the iodine tungsten lamp 602 and the photovoltaic panel 603.

[0020] Further, the indicating device on the electric circuit is a fan or an electric lamp. For example, the brightness of the electric lamp will play a role in local display.

[0021] The ammeters of the first water content detection element and the second water content detection element are electrically connected to the analog quantity processing module 8, and the analog quantity processing module is used to calculate the current values ​​of the two ammeters and the difference between the two ammeters. The analog quantity processing module 8 can be a PLC controller.

[0022] The first pressure reducing valve 402 is located at the process rear end of the first water content detection component, and the second pressure reducing valve 502 is located at the process rear end of the second water content detection component. The first pressure reducing valve 402 and the second pressure reducing valve 502 are used to slow down the flow rate and reduce the generation of bubbles; at the same time, ensure that the transparent box 601 is full.

[0023] Furthermore, a filter 7 is provided on the inlet pipe to filter out impurities to prevent the impurities from interfering with the test results.

[0024] The monitoring method of the oil-water mixing monitoring device of the vertical shaft semi-umbrella type hydro-turbine generator set comprises the following steps: Step 1: start the circulating oil pump on the outlet pipe of the derivation oil tank 1, adjust the size of the first pressure reducing valve 402 and the second pressure reducing valve 502, so that the oil fills the transparent box 601, and the oil in the transparent box 601 is not disturbed; the first U-shaped tube 401 and the second U-shaped tube 501 are used to introduce less oil into the transparent box 601, and the first pressure reducing valve 402 and the second pressure reducing valve 502 are used to prevent the oil in the transparent box 601 from flowing too fast and causing bubbles; Step 2: Turn on the iodine tungsten lamp 602, and the photovoltaic panel 603 will generate direct current when receiving light. When the oil does not contain water, the direct current is a stable value. The curve of the current I changing with time T is as follows: Figure 4 The stable value is a relatively stable curve, but not an absolutely horizontal straight line.

[0025] Step 3: When the water from the cooler enters the oil pipe, the mixture of oil and water will appear milky white, which will block the light transmittance of the oil, thereby affecting the power generation of the photovoltaic panel. When the current difference detected by the first water content detection component and the second water content detection component is greater than the threshold, it proves that the water from the cooler has entered the oil pipe. The curve of current I changing with time T is shown in the figure below: Figure 5 shown.

[0026] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for monitoring oil-water mixing in a derived oil tank of a hydro-generator set, characterized in that: A derivation oil tank oil-water mixing monitoring device is used, the derivation oil tank oil-water mixing monitoring device comprising a first water content detection device (4) installed on the outlet pipe of the derivation oil tank (1), and a second water content detection device (5) installed on the inlet pipe of the derivation oil tank (1), the water content difference between the second water content detection device (5) and the first water content detection device (4) is used to judge the degree of water leakage of the derivation oil tank (1); The first water content detection device (4) comprises a first U-shaped tube (401) and a first pressure reducing valve (402), and the second water content detection device (5) comprises a second U-shaped tube (501) and a second pressure reducing valve (502); The first water content detection device (4) and the second water content detection device (5) are both water content detection components (6), wherein the water content detection component (6) comprises a transparent box (601), an iodine tungsten lamp (602) is mounted on one side of the transparent box (601), and a photovoltaic panel (603) is mounted on the other side of the transparent box (601), the iodine tungsten lamp (602) and the photovoltaic panel (603) are arranged relative to each other, and the photovoltaic panel (603) is connected in series with an ammeter and an indicating device to form an electrical circuit; The monitoring methods are: Step 1, start the circulating oil pump on the outlet pipe of the derivation oil tank (1), adjust the sizes of the first pressure reducing valve (402) and the second pressure reducing valve (502), so that the oil fills the transparent box (601) and the oil in the transparent box (601) is not disturbed; the first U-shaped tube (401) and the second U-shaped tube (501) are used to introduce a small amount of oil into the transparent box (601), and the first pressure reducing valve (402) and the second pressure reducing valve (502) are used to prevent the oil in the transparent box (601) from flowing too fast and causing bubbles; Step 2, turning on the iodine tungsten lamp (602), the photovoltaic panel (603) receives light and generates direct current, and when the oil does not contain water, the direct current is a stable value; Step three, when the water from the cooler enters the oil pipe, the mixture of oil and water will appear milky white, which will block the light transmittance of the oil, thereby affecting the power generation of the photovoltaic panel. When the current difference detected by the first water content detection component and the second water content detection component is greater than the threshold value, it proves that the water from the cooler has entered the oil pipe.

2. The method for monitoring oil-water mixing in the oil tank of a hydro-generator set according to claim 1, characterized in that: The first U-shaped tube (401) is connected in parallel to the outlet pipeline, and a first pressure reducing valve (402) and a first water content detection component are installed on the first U-shaped tube (401); one end of the second U-shaped tube (501) is connected to the inlet pipeline, and the other end is connected to the derivation oil tank (1), and a second pressure reducing valve (502) and a second water content detection component are installed on the second U-shaped tube (501).

3. The method for monitoring oil-water mixing in the oil tank of a hydro-generator set according to claim 3 is characterized by: The transparent box (601) is a square box, and other surfaces of the transparent box (601) are provided with shading plates, wherein the other surfaces are the other four surfaces except the iodine tungsten lamp (602) and the photovoltaic panel (603).

4. The method for monitoring oil-water mixing in the derived oil tank of a hydro-generator set according to claim 3 is characterized by: The indicating device is a fan or a light.

5. The method for monitoring oil-water mixing in the derived oil tank of a hydro-generator set according to claim 3, characterized in that: The ammeters of the first water content detection component and the second water content detection component are electrically connected to an analog quantity processing module (8), and the analog quantity processing module is used to calculate the current values ​​of the two ammeters and calculate the difference between the two ammeters.

6. The method for monitoring oil-water mixing in the derived oil tank of a hydro-generator set according to claim 2, characterized in that: The first pressure reducing valve (402) is located at the process rear end of the first water content detection component, and the second pressure reducing valve (502) is located at the process rear end of the second water content detection component.

7. The method for monitoring oil-water mixing in the derived oil tank of a hydro-generator set according to claim 2, characterized in that: A filter (7) is provided on the inlet pipe.

Images