A 300MW unit high pressure regulating valve rear steam pipe drainage system

Abstract

A steam pipe drainage system after a high-pressure regulating valve of a 300MW unit belongs to the technical field of drainage systems. The utility model solves the problem that in the existing steam turbine body drainage system, the high-pressure steam pipe connected to the high-pressure regulating valve has different pressures in the pipe due to the different opening and closing states of the high-pressure regulating valve, resulting in a large pressure difference that affects the economic efficiency of the unit. The No. 1 high-pressure regulating valve of the utility model is connected to the high-pressure cylinder through the No. 1 high-pressure steam pipe, the No. 1 high-pressure steam pipe is connected to the main body drainage expansion tank through the No. 1 high-pressure steam pipe drainage pipe, the No. 1 high-pressure steam pipe drainage pipe is provided with a first manual stop valve, the No. 2 high-pressure regulating valve is connected to the high-pressure cylinder through the No. 2 high-pressure steam pipe, the No. 2 high-pressure steam pipe is connected to the main body drainage expansion tank through the No. 2 high-pressure steam pipe drainage pipe, and the No. 2 high-pressure steam pipe drainage pipe is provided with a second manual stop valve. The steam pipe drainage system of the utility model reduces the economic losses caused by the pressure difference.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbine high-pressure steam pipe drainage system, in particular to a 300MW unit high-pressure regulating valve rear steam pipe drainage system. Background Art

[0002] The steam turbine high-pressure steam pipe drain system is used to discharge a large amount of condensed water when the steam turbine is started and stopped. In order to effectively prevent water shock caused by turbine overspeed, overheating, water inflow accidents and water accumulation in the pipeline, the condensed water stored in the steam pipeline must be discharged in time to ensure the safe operation of the unit. At the same time, clean condensed water can also be recovered, which is beneficial to improving the economy of the unit. The system discharges the water generated by the high-pressure steam pipe of the steam turbine. These systems ensure that the inside of the steam turbine remains superheated steam, prevent corrosion and other damage to the steam turbine, and thus ensure the normal operation and long-term reliability of the steam turbine.

[0003] In the steam turbine high-pressure steam pipe drain system, the drain design of the steam pipe behind the high-pressure regulating valve is imperfect. Due to the different opening and closing states of each high-pressure regulating valve during operation, the pressure difference between the high-pressure steam pipes connected to the high-pressure regulating valve is large. At full load, the pressure difference between the two high-pressure steam pipes is about 5MPa. The two drain pipes are connected together, which will cause the high-pressure main steam in the high-pressure steam pipe with high pressure during operation to continuously flow into the high-pressure steam pipe with lower pressure. The resulting pressure loss affects the economy of the unit and causes certain economic losses.

[0004] Therefore, the present application proposes a steam pipe drainage system after the high-pressure regulating valve of a 300MW unit to solve the above problems. Utility Model Content

[0005] The purpose of the research and development of the utility model is to solve the problem that in the existing steam turbine body drain system, when the steam turbine is in the valve state, the high-pressure steam pipes connected to different high-pressure regulating valves have different pressures in the pipes due to the different opening and closing states of the high-pressure regulating valves, resulting in a large pressure difference that affects the economic efficiency of the unit and causes certain losses. A brief overview of the utility model is given below to provide a basic understanding of certain aspects of the utility model.

[0006] The technical solution of this utility model:

[0007] A steam pipe drain system after a high-pressure regulating valve of a 300MW unit comprises a No. 1 high-pressure regulating valve, a No. 2 high-pressure regulating valve, a No. 3 high-pressure regulating valve, a No. 4 high-pressure regulating valve, a first high-pressure main steam valve and a second high-pressure main steam valve, wherein the No. 1 high-pressure regulating valve is connected to a high-pressure cylinder through a No. 1 high-pressure steam pipe, the high-pressure cylinder is connected to the No. 4 high-pressure regulating valve through a No. 4 high-pressure steam pipe, the No. 1 high-pressure steam pipe is connected to a drain expansion tank to a main body through a No. 1 high-pressure steam pipe drain pipe, a first manual stop valve is arranged on the No. 1 high-pressure steam pipe drain pipe, the No. 2 high-pressure regulating valve is connected to the high-pressure cylinder through a No. 2 high-pressure steam pipe, the high-pressure cylinder is connected to the No. 3 high-pressure regulating valve through a No. 3 high-pressure steam pipe, the No. 2 high-pressure steam pipe is connected to the drain expansion tank to a main body through a No. 2 high-pressure steam pipe drain pipe, and a second manual stop valve is arranged on the No. 2 high-pressure steam pipe drain pipe.

[0008] Furthermore, the No. 1 high-pressure regulating valve and the No. 4 high-pressure regulating valve are connected to the first high-pressure main steam valve through a pipeline, and the No. 2 high-pressure regulating valve and the No. 3 high-pressure regulating valve are connected to the second high-pressure main steam valve through a pipeline.

[0009] Furthermore, the No. 4 high-pressure steam pipe is connected to the main body drain expansion tank through the No. 4 high-pressure steam pipe drain pipe, the No. 1 high-pressure steam pipe drain pipe and the No. 4 high-pressure steam pipe drain pipe are gathered into the same pipeline and connected to the main body drain expansion tank, and the first drain valve and the first drain pneumatic main valve are arranged on the pipeline.

[0010] Furthermore, the No. 3 high-pressure steam pipe is connected to the main body drain expansion tank through the No. 3 high-pressure steam pipe drain pipe, the No. 2 high-pressure steam pipe drain pipe and the No. 3 high-pressure steam pipe drain pipe are gathered into the same pipeline and connected to the main body drain expansion tank, and a second drain pneumatic main valve and a second drain valve are arranged on the pipeline.

[0011] The utility model has the following beneficial effects:

[0012] The utility model discloses a steam pipe drain system after a high-pressure regulating valve of a 300MW unit. When the steam turbine is in sequential operation, on the basis of the original drain system, a first manual stop valve and a second manual stop valve are respectively installed on the No. 1 high-pressure steam pipe drain pipe of the No. 1 high-pressure steam pipe with large internal pressure and on the No. 2 high-pressure steam pipe drain pipe of the No. 2 high-pressure steam pipe. When the equipment is started and stopped, the first manual stop valve and the second manual stop valve are opened to discharge the high-pressure main steam in the No. 1 high-pressure steam pipe and the No. 2 high-pressure steam pipe from the No. 1 high-pressure steam pipe drain pipe and the No. 2 high-pressure steam pipe drain pipe to the de-body drain expansion tank and the de-body drain expansion tank, so that there is no large pressure difference between the No. 1 high-pressure steam pipe and the No. 4 high-pressure steam pipe, and there is no large pressure difference between the No. 2 high-pressure steam pipe and the No. 3 high-pressure steam pipe, thereby reducing the economic loss caused by the pressure difference and improving the economy of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the steam pipe drain system after the high-pressure regulating valve of a 300MW unit.

[0014] In the figure: 1-No. 1 high-pressure regulating valve, 2-No. 2 high-pressure regulating valve, 3-No. 3 high-pressure regulating valve, 4-No. 4 high-pressure regulating valve, 5-first high-pressure main steam valve, 6-second high-pressure main steam valve, 7-No. 1 high-pressure steam pipe, 8-No. 2 high-pressure steam pipe, 9-No. 3 high-pressure steam pipe, 10-No. 4 high-pressure steam pipe, 11-high-pressure cylinder, 12-first manual stop valve, 13-second manual stop valve, 14-first drain pneumatic main valve, 15-first drain valve, 16-second drain pneumatic main valve, 17-second drain valve, 18-body drain expansion tank, 20-No. 1 high-pressure steam pipe drain pipe, 21-No. 4 high-pressure steam pipe drain pipe, 22-No. 2 high-pressure steam pipe drain pipe, 23-No. 3 high-pressure steam pipe drain pipe. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is described below by specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0016] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection (i.e., non-detachable connection) includes but is not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection, and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as threaded connection, snap connection, pin connection, and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and hinge connection is selected for detachable connection.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] Embodiment 1, combination Figure 1The embodiment is described. A 300MW unit high-pressure regulating valve rear steam pipe drainage system in the embodiment comprises a No. 1 high-pressure regulating valve 1, a No. 2 high-pressure regulating valve 2, a No. 3 high-pressure regulating valve 3, a No. 4 high-pressure regulating valve 4, a first high-pressure main steam valve 5 and a second high-pressure main steam valve 6. The No. 1 high-pressure regulating valve 1 is connected to a high-pressure cylinder 11 through a No. 1 high-pressure steam pipe 7. The high-pressure cylinder 11 is connected to the No. 4 high-pressure regulating valve 4 through a No. 4 high-pressure steam pipe 10. The No. 1 high-pressure steam pipe 7 is connected to the No. 1 high-pressure main steam valve 5 through a No. 1 high-pressure main steam valve 6. The steam pipe drain pipe 20 is connected to the de-body drain expansion tank 18, a first manual stop valve 12 is arranged on the No. 1 high-pressure steam pipe drain pipe 20, the No. 2 high-pressure regulating valve 2 is connected to the high-pressure cylinder 11 through the No. 2 high-pressure steam pipe 8, the high-pressure cylinder 11 is connected to the No. 3 high-pressure regulating valve 3 through the No. 3 high-pressure steam pipe 9, the No. 2 high-pressure steam pipe 8 is connected to the de-body drain expansion tank 18 through the No. 2 high-pressure steam pipe drain pipe 22, and a second manual stop valve 13 is arranged on the No. 2 high-pressure steam pipe drain pipe 22.

[0019] When the equipment is running, the No. 1 high-pressure regulating valve 1 and the No. 2 high-pressure regulating valve 2 are in the normally open state, the No. 4 high-pressure regulating valve 4 is in the normally closed state, and the No. 3 high-pressure regulating valve 3 is appropriately half-opened according to the on-site conditions. Therefore, when the equipment is started and shut down, the normally open state of the No. 1 high-pressure regulating valve 1 and the No. 2 high-pressure regulating valve 2 is compared with the half-open state of the No. 3 high-pressure regulating valve 3 and the normally closed state of the No. 4 high-pressure regulating valve 4. A large pressure difference will be formed between the No. 1 high-pressure steam pipe 7 and the No. 4 high-pressure steam pipe 10, and a large pressure difference will also be formed in the No. 2 high-pressure steam pipe 8 and the No. 3 high-pressure steam pipe 9, resulting in a large pressure loss;

[0020] In order to reduce the pressure difference between the No. 1 high-pressure steam pipe 7 and the No. 4 high-pressure steam pipe 10, and between the No. 2 high-pressure steam pipe 8 and the No. 3 high-pressure steam pipe 9, a No. 1 high-pressure steam pipe drain pipe 20 is connected to the pipeline of the No. 1 high-pressure steam pipe 7, and is connected to the main body drain expansion container 18 through the No. 1 high-pressure steam pipe support rod 20. A first manual stop valve 12 is arranged on the No. 1 high-pressure steam pipe drain pipe 20, and the model of the first manual stop valve 12 is J61Y-P55-170V-DN50MM. A No. 2 high-pressure steam pipe drain pipe 22 is connected to the pipeline of the No. 2 high-pressure steam pipe 8, and is connected to the main body drain expansion container 18 through the No. 2 high-pressure steam pipe drain pipe 22. A second manual stop valve 13 is installed on the pipeline of the No. 2 high-pressure steam pipe drain pipe 22, and the model of the second manual stop valve 13 is J61Y-P55-170V-DN50MM. When the equipment is started When shutting down, the first manual stop valve 12 and the second manual stop valve 13 are opened, and part of the high-pressure main steam in the No. 1 high-pressure steam pipe 7 and the No. 2 high-pressure steam pipe 8 is respectively input into the de-body water-draining expansion tank 18 and the de-body water-draining expansion tank 18 through the No. 1 high-pressure steam pipe drain pipe 20 and the No. 2 high-pressure steam pipe drain pipe 22, and the remaining high-pressure main steam flows into the high-pressure cylinder 11, and then is respectively output through the No. 3 high-pressure steam pipe 9 and the No. 4 high-pressure steam pipe 10. The No. 3 high-pressure steam pipe 9 is connected to the No. 3 high-pressure steam pipe drain pipe 23, and the No. 4 high-pressure steam pipe 10 is connected to the No. 4 high-pressure steam pipe drain pipe 21. The steam is discharged into the de-body water-draining expansion tank 10 and the de-body water-draining expansion tank 18 through the No. 3 high-pressure steam pipe drain pipe 23 and the No. 4 high-pressure steam pipe drain pipe 21. When the equipment is operating normally, the first manual stop valve 12 and the second manual stop valve 13 are closed;

[0021] The No. 1 high-pressure steam pipe drain pipe 20 and the No. 4 high-pressure steam pipe drain pipe 21 are merged into the same pipeline and output to the main body drain expansion tank 18, on which the first drain pneumatic main valve 14 and the first drain valve 15 are installed, and the first drain pneumatic main valve 14 and the first drain valve 15 are in a normally open state. The No. 2 high-pressure steam pipe drain pipe 22 and the No. 3 high-pressure steam pipe drain pipe 23 are merged into the same pipeline and output to the main body drain expansion tank 18, on which the second drain pneumatic main valve 16 and the second drain valve 17 are installed, and the second drain pneumatic main valve 16 and the second drain valve 17 are in a normally open state.

[0022] This embodiment is only an illustrative description of the present application and does not limit its protection scope. Those skilled in the art may also make partial changes thereto, and as long as they do not exceed the spirit of the present application, they are all within the protection scope of the present application.

Claims

1. A 300MW unit high-pressure regulating valve rear steam pipe drainage system, characterized by: The invention comprises a No. 1 high-pressure regulating valve (1), a No. 2 high-pressure regulating valve (2), a No. 3 high-pressure regulating valve (3), a No. 4 high-pressure regulating valve (4), a first high-pressure main steam valve (5) and a second high-pressure main steam valve (6); the No. 1 high-pressure regulating valve (1) is connected to a high-pressure cylinder (11) through a No. 1 high-pressure steam pipe (7); the high-pressure cylinder (11) is connected to the No. 4 high-pressure regulating valve (4) through a No. 4 high-pressure steam pipe (10); the No. 1 high-pressure steam pipe (7) is connected to a main body drain expansion container (11) through a No. 1 high-pressure steam pipe drain pipe (20) 8), a first manual stop valve (12) is arranged on the No. 1 high-pressure steam pipe drain pipe (20), a No. 2 high-pressure regulating valve (2) is connected to the high-pressure cylinder (11) through the No. 2 high-pressure steam pipe (8), the high-pressure cylinder (11) is connected to the No. 3 high-pressure regulating valve (3) through the No. 3 high-pressure steam pipe (9), the No. 2 high-pressure steam pipe (8) is connected to the main body drain expansion container (18) through the No. 2 high-pressure steam pipe drain pipe (22), and a second manual stop valve (13) is arranged on the No. 2 high-pressure steam pipe drain pipe (22).

2. A 300MW unit high-pressure regulating valve rear steam pipe drainage system according to claim 1, characterized in that: The No. 1 high-pressure regulating valve (1) and the No. 4 high-pressure regulating valve (4) are connected to the first high-pressure main steam valve (5) through pipelines, and the No. 2 high-pressure regulating valve (2) and the No. 3 high-pressure regulating valve (3) are connected to the second high-pressure main steam valve (6) through pipelines.

3. A 300MW unit high-pressure regulating valve rear steam pipe drainage system according to claim 2, characterized in that: The No. 4 high-pressure steam pipe (10) is connected to the main body drain expansion tank (18) through the No. 4 high-pressure steam pipe drain pipe (21); the No. 1 high-pressure steam pipe drain pipe (20) and the No. 4 high-pressure steam pipe drain pipe (21) are collected on the same pipeline and connected to the main body drain expansion tank (18); a first drain valve (15) and a first drain pneumatic main valve (14) are arranged on the pipeline.

4. A 300MW unit high-pressure regulating valve rear steam pipe drainage system according to claim 2, characterized in that: The No. 3 high-pressure steam pipe (9) is connected to the main body drain expansion tank (18) via the No. 3 high-pressure steam pipe drain pipe (23); the No. 2 high-pressure steam pipe drain pipe (22) and the No. 3 high-pressure steam pipe drain pipe (23) are collected on the same pipeline and connected to the main body drain expansion tank (18); a second drain pneumatic main valve (16) and a second drain valve (17) are provided on the pipeline.

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