Protection device for monitoring oil level of main oil tank of steam turbine

Abstract

The utility model relates to the technical field of oil tank oil level detection, and discloses a protection device for monitoring the oil level of a main oil tank of a steam turbine, which comprises a differential pressure transmitter, the differential pressure transmitter comprises a positive pressure detection port and a negative pressure detection port, and the outer wall of the main oil tank is provided with a first sampling hole and a second sampling hole. The first sampling hole is located above the liquid level of the maximum oil storage amount of the main oil tank, the second sampling hole is located in the lower end of the main oil tank, and the first sampling hole and the second sampling hole are communicated with the negative pressure detection port and the positive pressure detection port through connecting pieces respectively. The differential pressure transmitter can measure the pressure change in the main oil tank through the negative pressure detection port and the positive pressure detection port to calculate the oil level; the negative pressure detection port and the positive pressure detection port are connected with the first sampling hole and the second sampling hole respectively, the oil level is calculated according to the pressure difference in the main oil tank caused by oil level change, and the detection mode eliminates interference of zero position change caused by factors such as micro negative pressure generated when the main oil tank works on a measurement result.

Description

Technical Field

[0001] This utility model relates to the field of oil tank level detection technology, specifically to a protection device for monitoring the oil level in the main oil tank of a steam turbine. Background Technology

[0002] In the existing turbine oil tank level measurement system, only a single inductive oil level measuring device is configured for local measurement. This device can sense changes in oil level in real time and transmit the generated inductive signal to a locally installed secondary instrument. The secondary instrument processes the signal and converts it into a 4-20mA standard signal with a range of ±400mm. The signal is then transmitted to the DCS system to realize real-time display of oil level data and over-limit alarm function.

[0003] Existing technologies use a fixed normal oil level as the zero-point reference. However, during long-term operation, the actual oil level in the tank may change due to factors such as slight negative pressure generated during operation and the accumulation of impurities. If the operator fails to recalibrate the zero point in time, it will cause systematic deviations in the measurement results, affecting the accuracy and reliability of the oil level data. To address this issue, we propose a protective device for monitoring the oil level in the main oil tank of a steam turbine. Utility Model Content

[0004] The present invention aims to provide a protective device for monitoring the oil level in the main oil tank of a steam turbine, in order to solve the problem that during long-term operation, the actual oil level in the tank may change due to factors such as the accumulation of impurities and equipment deformation, resulting in systematic deviations in the measurement results and affecting the accuracy and reliability of the oil level data.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a protection device for monitoring the oil level in the main oil tank of a steam turbine, comprising a differential pressure transmitter installed on one side of the main oil tank, the differential pressure transmitter including a positive pressure detection port and a negative pressure detection port, a first sampling port and a second sampling port being provided on the outer wall of the main oil tank, the first sampling port being located above the liquid level of the main oil tank at its maximum storage capacity, and the second sampling port being located on the lower outer wall of the main oil tank, the first sampling port and the second sampling port being connected to the negative pressure detection port and the positive pressure detection port respectively through connecting parts, the differential pressure transmitter being able to measure the pressure change in the main oil tank through the negative pressure detection port and the positive pressure detection port to calculate the oil level.

[0006] The beneficial effects of this scheme are as follows: By connecting the negative pressure detection port and positive pressure detection port of the differential pressure transmitter to the first sampling port above the liquid level in the main oil tank and the second sampling port at the bottom, respectively, the oil level is calculated by utilizing the pressure difference in the main oil tank caused by changes in oil level. This detection method eliminates the interference of zero-point changes caused by factors such as slight negative pressure generated during the operation of the main oil tank and the accumulation of impurities on the measurement results. Compared with inductive oil level measuring devices, it can more accurately and stably reflect the actual oil level height, reduce measurement errors, and in this scheme, even under special operating conditions such as turbine startup, shutdown, and drastic load changes, which cause large fluctuations in the oil level in the main oil tank, the differential pressure transmission can accurately measure the oil level by the change in pressure difference in the main oil tank.

[0007] Preferably, as an improvement, the connector is made of seamless steel pipe.

[0008] The beneficial effects are as follows: Seamless steel pipes have no longitudinal welds during the production process, and the structure is continuous and complete. Compared with welded steel pipes, they can effectively avoid leakage problems caused by poor sealing at the welds. When the first and second sampling holes are connected to the differential pressure transmitter respectively, the integrity of the pressure signal transmission can be ensured, preventing the ingress of outside air or leakage of oil vapor in the main oil tank, ensuring the accuracy of differential pressure measurement, and avoiding measurement errors and safety hazards caused by leakage.

[0009] Preferably, as an improvement, the distance between the first sampling hole and the upper wall of the main oil tank is set to 120-160mm.

[0010] The beneficial effects are as follows: by setting the distance between the first sampling hole and the upper wall of the main oil tank to 120-160mm, it can prevent oil from flowing back into the negative pressure pipeline of the differential pressure transmitter, avoid measurement failure caused by oil blockage or pipeline corrosion, and improve system reliability.

[0011] Preferably, as an improvement, the distance between the second sampling hole and the lower wall of the main oil tank is set to 240-280mm.

[0012] The beneficial effects are as follows: by setting the distance between the second sampling port and the lower wall of the main oil tank to 240-280mm, the area of ​​impurities such as sludge and metal debris deposited at the bottom of the main oil tank can be avoided. Since the positive pressure detection port of the differential pressure transmitter collects pressure through the second sampling port, if the second sampling port is close to the bottom of the main oil tank, impurities may block the second sampling port, causing abnormal pressure and affecting the measurement accuracy.

[0013] Preferably, the diameters of the first sampling hole and the second sampling hole are set to 14 mm.

[0014] Preferably, the thickness of the seamless steel pipe is set to 2mm.

[0015] Preferably, as an improvement, the protection device is configured with three sets, and two sets of consistent or close measurement data are selected from the three sets of measurement data as the true data.

[0016] The beneficial effects are as follows: when a data deviation occurs in one of the devices due to sensor failure, abnormal signal transmission, or component damage, by comparing the three sets of data and selecting two sets of consistent or close data as the true data, the oil level monitoring failure caused by the failure of a single device can be effectively avoided, ensuring the continuous and stable operation of the turbine main oil tank oil level monitoring system and reducing the risk of equipment failure or safety accidents caused by monitoring data errors. Attached Figure Description

[0017] Figure 1 This is a front view of the main oil tank and protection device according to an embodiment of the present invention. Detailed Implementation

[0018] The following detailed description illustrates the specific implementation method:

[0019] The reference numerals in the accompanying drawings include: 1. Main oil tank; 2. Sludge oil area; 3. Clean oil area; 4. Differential pressure transmitter; 5. Positive pressure detection port; 6. Negative pressure detection port; 7. First sampling port; 8. Second sampling port; 9. Connecting component.

[0020] Example

[0021] The basic implementation examples are as follows: Figure 1 As shown, Figure 1The protective device shown is for monitoring the oil level of the main oil tank 1 of a steam turbine. It includes a main oil tank 1, a sludge zone 2 on the left side of the main oil tank 1, and a clean oil zone 3 on the right side of the main oil tank 1. The sludge zone 2 and the clean oil zone 3 are separated by a metal plate. It also includes a differential pressure transmitter 4 located on the right side of the main oil tank 1. The differential pressure transmitter 4 includes a positive pressure detection port 5 and a negative pressure detection port 6. A first sampling hole 7 and a second sampling hole 8 are provided on the outer wall of the main oil tank 1. The diameters of the first sampling hole 7 and the second sampling hole 8 are set to 14 mm. The first sampling hole 7 is located above the maximum oil level of the main oil tank 1, and the distance between the first sampling hole 7 and the upper wall of the main oil tank 1 is set to 120-160 mm. The second sampling hole 8 is located on the lower outer wall of the main oil tank 1, and the distance between the second sampling hole 8 and the lower wall of the main oil tank 1 is set to 240-280 mm. The second sampling port 8 is connected to the negative pressure detection port 6 and the positive pressure detection port 5 respectively through the connector 9. The connector 9 is made of seamless steel pipe with a thickness of 2mm. The differential pressure transmitter 4 can measure the pressure change in the main oil tank 1 through the negative pressure detection port 6 and the positive pressure detection port 5 to calculate the oil level. In this embodiment, the protection device is set to three sets, and two sets of consistent or close measurement data are selected from the three sets of measurement data as the real data. In order to avoid the AC oil pump, DC oil pump, oil injector and other devices in the main oil tank 1 from affecting the first sampling port 7 and the second sampling port 8 when they are operating, the first sampling port 7 and the second sampling port 8 are kept at a safe distance of 600-800mm from the AC oil pump, DC oil pump, oil injector and other devices. The first sampling port 7 is opened at a distance of 200-400mm from the edge of the manhole door of the main oil tank 1.

[0022] The specific implementation process is as follows:

[0023] By connecting the negative pressure detection port 6 and positive pressure detection port 5 of the differential pressure transmitter 4 to the first sampling port 7 above the liquid surface of the main oil tank 1 and the second sampling port 8 at the bottom, respectively, the oil level is calculated using the pressure difference in the main oil tank 1 caused by the change in oil level. This detection method eliminates the interference of zero-point changes caused by factors such as the slight negative pressure generated during the operation of the main oil tank 1 and the accumulation of impurities on the measurement results. Compared with the inductive oil level measuring device, it can more accurately and stably reflect the actual oil level height, reduce measurement errors, and by comparing three sets of data and selecting two sets of consistent or close data as the true data, it can effectively avoid the failure of oil level monitoring caused by the failure of a single device, ensure the continuous and stable operation of the turbine main oil tank 1 oil level monitoring system, and reduce the risk of equipment failure or safety accidents caused by incorrect monitoring data.

[0024] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A protection device for turbine main tank level monitoring, characterized by: The differential pressure transmitter is arranged on one side of the main oil tank, and includes a positive pressure detection port and a negative pressure detection port.

2. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 1, characterized in that: The connecting piece is a seamless steel pipe.

3. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 2, characterized in that: The distance between the first sampling hole and the upper wall of the main oil tank is 120-160 mm.

4. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 3, characterized in that: The distance between the second sampling hole and the lower wall of the main oil tank is 240-280 mm.

5. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 4, characterized in that: The diameters of the first sampling hole and the second sampling hole are 14 mm.

6. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 5, characterized in that: The thickness of the seamless steel pipe is 2 mm.

7. A protection device for oil level monitoring of a main oil reservoir of a steam turbine according to claim 1, characterized in that: The protection device is three groups, and two consistent or close measurement data are selected from the three groups of measurement data as true data.

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