A method for expanding capacity of a transformer substation accident oil sump

Abstract

The application discloses a method for expanding capacity of an oil pool for transformer substation accidents, which comprises the following steps: switching the oil outlet of a main transformer to be communicated with a temporary oil tank; expanding the capacity of an original oil pool for accidents during the connection of the temporary oil tank and the oil outlet of the main transformer, and transforming the original oil pool for accidents into an oil pool for accidents with an effective capacity of more than 100% of the maximum oil volume of a single device; and connecting the oil outlet of the main transformer to the expanded oil pool for accidents after the expansion and transformation of the original oil pool for accidents are completed. The method can solve the problem that the prior art cannot expand the oil pool for accidents under the condition of ensuring safety in the case of a small site.

Description

TECHNICAL FIELD

[0001] The application relates to a method for expanding the capacity of an accident oil pool of a transformer substation and belongs to the technical field of the accident oil pool of the transformer substation. BACKGROUND

[0002] In 2019, the new national standard "Design Fireproof Standard for Thermal Power Plants and Transformer Substations (GB 50229-2019)" was introduced. The effective volume standard of the accident oil pool of the transformer substation has changed from 60% of the maximum oil volume of a single device to 100%. The change of the national standard leads to the need to expand the effective volume of the accident oil pool of the transformer substation. In the existing method, the capacity is expanded mainly by the following two methods:

[0003] 1) The original accident oil pool is demolished and rebuilt to expand its capacity.

[0004] 2) A small accident oil pool is added next to the original accident oil pool to achieve capacity expansion by being connected in series with the original accident oil pool.

[0005] The problem with method 1) is that it is risky because the function of the original accident oil pool needs to be stopped for the demolition and reconstruction of the original accident oil pool. However, if an accident occurs during the demolition and reconstruction of the original accident oil pool, the accident oil pool will not be able to accommodate the oil of the main transformer, resulting in an accident.

[0006] The problem with method 2) is that, first, in the case of a small site, there is not enough space to directly add an accident oil pool; second, the small accident oil pool needs to be lower in elevation than the original accident oil pool to form a pressure difference to make the oil flow into the small accident oil pool. The above two conditions limit the feasibility of this scheme.

[0007] Therefore, there is an urgent need for a method for expanding the accident oil pool under the condition of ensuring safety in the case of a small site. SUMMARY

[0008] The technical problem to be solved by the application is to provide a method for expanding the capacity of an accident oil pool of a transformer substation to overcome the shortcomings of the prior art.

[0009] The technical scheme of the application is a method for expanding the capacity of an accident oil pool of a transformer substation, which comprises:

[0010] Switching the oil outlet of the main transformer to be in communication with the temporary oil tank;

[0011] Expanding the capacity of the original accident oil pool during the connection of the temporary oil tank and the oil outlet of the main transformer, and reforming the original accident oil pool into an accident oil pool with an effective volume of more than 100% of the maximum oil volume of a single device;

[0012] Connecting the oil outlet of the main transformer to the expanded accident oil pool after the expansion and reform of the original accident oil pool are completed.

[0013] Before switching the main transformer oil outlet to communicate with the temporary oil tank, the temporary oil tank is filled with inert gas or nitrogen, so that the air in the temporary oil tank is replaced by inert gas or nitrogen.

[0014] Further, the temporary oil tank comprises a controller, a tank body, a flow meter and a gas suction pump;

[0015] The tank body is a sealed tank body, and the effective volume of the tank body is more than 100% of the maximum oil volume of a single device; the tank body communicates with the main transformer oil outlet; the flow meter is arranged on the main transformer oil outlet; and the gas suction pump communicates with the upper part of the tank body.

[0016] Further, a collection container is further included, and the collection container communicates with the tank body through the gas suction pump.

[0017] Further, an electromagnetic valve is further included, and the electromagnetic valve is arranged between the collection container and the gas suction pump, and the electromagnetic valve is electrically connected with the controller.

[0018] Further, the method for the controller to control the gas suction pump and the electromagnetic valve is:

[0019] The oil outlet flow rate of the main transformer oil outlet is monitored through the flow meter; if the accumulated oil outlet flow rate of the main transformer oil outlet is less than a first set accumulated threshold value and the oil outlet flow rate is greater than a first set flow rate threshold value, the controller controls the electromagnetic valve to open and controls the gas suction pump to suck gas; when the flow meter monitors that the accumulated oil outlet volume of the main transformer oil outlet is greater than a second set accumulated threshold value and the oil outlet flow rate is greater than a second set flow rate threshold value, the electromagnetic valve is controlled to close and the gas suction pump is controlled to stop sucking gas.

[0020] Specifically, the calculation method of the accumulated oil outlet volume of the main transformer oil outlet is:

[0021]

[0022] Wherein, Q is the accumulated oil outlet volume of the main transformer oil outlet, S is the cross-sectional area of the main transformer oil outlet, and t is the accumulated monitoring time of the flow meter.

[0023] The beneficial effects of the present application are:

[0024] 1) During the expansion of the accident oil pool, the temporary oil tank replaces the original accident oil pool, and after the expansion of the accident oil pool is completed, the main transformer oil outlet is connected to the expanded accident oil pool, which ensures safety, and when the original accident oil pool is expanded, the temporary oil tank can play the original role of the accident oil pool even if an accident occurs in the main transformer, and space is not occupied, and when the expansion of the main transformer is completed, the temporary oil tank can be removed and replaced with the expanded accident oil pool;

[0025] 2) The present application uses inert gas, so that the oil of the main transformer does not contact with oxygen after entering the temporary oil tank, thereby reducing the probability of explosion and combustion accident.

[0026] 3) The application monitors whether the main transformer is oiling through the flow meter, and if it is oiling, the inert gas in the tank is extracted by the air extraction pump to generate negative pressure in the tank, thereby extracting the oil in the main transformer, solving the problem of low hydraulic pressure and poor oiling of the main transformer due to the small height difference between the main transformer and the tank;

[0027] 4) The application collects the inert gas extracted from the tank by the air extraction pump to recycle and reduce the use cost;

[0028] 5) The application uses the electromagnetic valve to close the gas collection container to prevent the inert gas or nitrogen in the gas collection container from leaking when the air extraction pump is not working;

[0029] 6) The application uses the main transformer oil outlet flow accumulation to determine the electromagnetic valve and the air extraction pump start-stop, avoiding the problem of physical devices such as liquid level meters being easily damaged, and combining the flow rate threshold as a determination condition to avoid the misjudgment problem caused by the cumulative error of the flow meter. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the flow chart of the embodiment of the application;

[0031] Figure 2 is the circuit connection block diagram of the application. DETAILED DESCRIPTION

[0032] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings and specific embodiments of the specification.

[0033] Embodiment Example 1:

[0034] Reference Figure 1 and Figure 2 In order to expand the accident oil pool under the condition of small site and ensure safety, the following method is adopted in this embodiment, which includes the following steps:

[0035] Switch the main transformer 1 oil outlet to be connected with the temporary oil tank. This can be achieved by manual switching.

[0036] During the connection of the temporary oil tank and the main transformer 1 oil outlet, the original accident oil pool is expanded and modified, and the effective volume of the accident oil pool is modified to be more than 100% of the maximum oil volume of a single device. This can be achieved by installing a larger temporary oil tank around the original accident oil pool, and the effective volume of the temporary oil tank is increased to more than 100% of the maximum oil volume of a single device.

[0037] After the expansion of the original oil pool is completed, the oil outlet of the main transformer 1 is connected to the expanded oil pool. This can be achieved by manual switching and the like.

[0038] In order to ensure the safety of the operation, the following steps need to be taken during the operation:

[0039] Before switching the oil outlet of the main transformer 1 to be connected to the temporary oil tank, inert gas or nitrogen is filled into the temporary oil tank. This can be achieved by connecting the collection container 6 and the air pump 4, so as to replace the air in the temporary oil tank with inert gas or nitrogen, thereby reducing the risk of explosion.

[0040] The temporary oil tank includes a controller, a tank body 2, a flow meter 3 and an air pump 4. The tank body 2 is a sealed tank body 2 with an effective volume of more than 100%, and the flow meter 3 is arranged on the oil outlet of the main transformer 1. The air pump 4 is in communication with the upper part of the tank body 2, and the air pressure in the tank body 2 can be controlled by controlling the air pump 4 through the controller.

[0041] The electromagnetic valve 5 can be arranged between the collection container 6 and the air pump 4, for controlling the opening and closing of the collection container 6. The controller can control the operation of the electromagnetic valve 5 and the air pump 4 by monitoring the oil flow rate of the oil outlet of the main transformer 1. For example, when the oil flow rate is greater than a first set flow rate threshold and the cumulative oil output is less than a first set cumulative threshold, the controller can open the electromagnetic valve 5 and control the air pump 4 to perform air pumping. When the oil flow rate is greater than a second set flow rate threshold and the cumulative oil output is greater than a second set cumulative threshold, the controller can close the electromagnetic valve 5 and stop the operation of the air pump 4.

[0042] Specifically, the calculation method of the cumulative oil output of the oil outlet of the main transformer 1 is as follows:

[0043]

[0044] Wherein, Q is the cumulative oil output of the oil outlet of the main transformer 1, S is the cross-sectional area of the oil outlet of the main transformer 1, and t is the cumulative monitoring time of the flow meter 3.

[0045] The above is a further detailed description of the present application in combination with a specific preferred embodiment, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be regarded as falling within the protection scope of the present application.

Claims

1. A method of expanding the capacity of a transformer substation accident oil sump, characterized by, The method comprises: Switching the oil outlet of the main transformer (1) to communicate with the temporary oil tank; During the connection of the temporary oil tank and the oil outlet of the main transformer (1), expanding the original emergency oil tank, and transforming it into an emergency oil tank with an effective volume of more than 100% of the maximum oil volume of a single device; After the expansion and transformation of the original emergency oil tank are completed, connecting the oil outlet of the main transformer (1) to the expanded emergency oil tank; The temporary oil tank comprises a controller, a tank body (2), a flow meter (3), and a gas suction pump (4); The tank body (2) is a sealed tank body (2), and the effective volume of the tank body (2) is more than 100% of the maximum oil volume of a single device. The tank body (2) communicates with the oil outlet of the main transformer (1), the flow meter (3) is arranged on the oil outlet of the main transformer (1), and the gas suction pump (4) communicates with the upper part of the tank body (2); It also comprises a collection container (6) which communicates with the tank body (2) through the gas suction pump (4); It also comprises a solenoid valve (5) which is arranged between the collection container (6) and the gas suction pump (4) and is electrically connected with the controller; The method for the controller to control the gas suction pump (4) and the solenoid valve (5) is as follows: The flow meter (3) is used to monitor the oil outlet flow of the main transformer (1). If the cumulative oil outlet flow of the main transformer (1) is less than a first set cumulative threshold value and the oil outlet flow is greater than a first set flow rate threshold value, the controller controls the solenoid valve (5) to open and controls the gas suction pump (4) to suck gas. When the flow meter (3) monitors that the cumulative oil outlet volume of the main transformer (1) is greater than a second set cumulative threshold value and the oil outlet flow is greater than a second set flow rate threshold value, the solenoid valve (5) is controlled to close and the gas suction pump (4) is controlled to stop sucking gas.

2. The method of expanding the capacity of a transformer substation emergency sump according to claim 1, wherein, Before the oil outlet of the main transformer (1) is switched to communicate with the temporary oil tank, inert gas or nitrogen is filled into the temporary oil tank, so that the air in the temporary oil tank is replaced by inert gas or nitrogen.

3. The method of expanding the capacity of a transformer substation accident sump according to claim 1, characterized in that, The calculation method of the cumulative oil outlet volume of the oil outlet of the main transformer (1) is as follows: ； Wherein, Q is the cumulative oil outlet volume of the oil outlet of the main transformer (1), S is the cross-sectional area of the oil outlet of the main transformer (1), and t is the cumulative monitoring time of the flow meter (3).

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