Drainage system for high-pressure heater of steam turbine in power plant
By introducing an emergency drain bypass and combined valve control into the high-pressure heater drain system, the problem of water level fluctuation in the high-pressure heater was solved, safe and controllable water level regulation was achieved, maintenance costs were reduced, and safe operation of the unit was ensured.
Patent Information
- Application Number
- CN202422654896.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-10-30
AI Technical Summary
During the operation of the high-pressure heater, the water level on the steam side is high and fluctuates greatly, which affects heat transfer and causes the risk of water backflow. In addition, the emergency drain electric door is easily damaged, affecting the safe operation of the unit and making spare parts expensive.
A power plant steam turbine high-pressure heater drain system is designed, including a main emergency drain line and a bypass. Through a combination of manual and electric valves, the emergency drain bypass is used as an auxiliary drain to adjust the high-pressure heater water level to avoid failure of the main emergency drain line. Manual valves are used as shut-off and regulating valves to ensure that the water level is controlled within a safe range.
Effectively controlling the water level of the high-pressure heater reduces maintenance costs, avoids the replacement of expensive spare parts, ensures the safe operation of the equipment, and has high feasibility and significant economic benefits.
Smart Images
Figure CN223399753U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of power plants, and in particular relates to a steam turbine high-pressure heater drain system for a power plant. Background Art
[0002] During operation of the high-pressure heater, the steam side water level is high and fluctuates greatly. When the unit is running at full load, the main regulating drain adjustment valve of the main steam side of the high-pressure heater is close to the fully open state, the steam side water level of the high-pressure heater is high (close to the high water level alarm value), and the water level of the high-pressure heater steam side cannot be maintained stable. The high steam side water level of the high-pressure heater will directly affect the heat transfer of the high-pressure heater, and even water will flow back into the steam turbine, causing water hammer accidents. However, due to the structure of the high-pressure heater, it cannot be repaired on site. If the internal leakage increases, it is necessary to open the high-pressure heater steam side emergency drain electric valve for auxiliary draining. The emergency drain electric valve is an imported part and the spare part is expensive. In addition, because the working medium of the emergency drain electric valve is a steam-water mixture, the working conditions are harsh, and the valve internals are easily washed away, which leads to the valve internal leakage and cannot be closed tightly. In addition, it is difficult to isolate the system, which will seriously affect the safe operation of the unit and even cause the unit to stop. Utility Model Content
[0003] The technical problem to be solved by the present invention is to provide a steam turbine high-pressure heater drain system for a power plant, which can effectively solve the problems of the prior art in that the steam side water level is high and fluctuates greatly during the operation of the high-pressure heater, the replacement cost of parts is expensive, and the safe operation of the unit is seriously affected.
[0004] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:
[0005] A power plant steam turbine high-pressure heater drain system includes multiple high-pressure heaters, an emergency drain main line, an emergency drain bypass and an accident expansion tank. The first high-pressure heater is connected to the steam turbine, and the multiple high-pressure heaters are connected in sequence by pipelines. The last high-pressure heater is connected to a deaerator through a pipeline. The multiple high-pressure heaters are all connected to the emergency drain main line and the emergency drain bypass. The high-pressure heaters are provided with a main drain port and an emergency drain port. One end of the emergency drain main line is connected to the main drain port, and the other end of the emergency drain main line is connected to the accident expansion tank. The emergency drain main line is provided with a first drain valve and a second drain valve. One end of the emergency drain bypass is connected to the emergency drain port, and the other end of the emergency drain bypass is connected to the accident expansion tank. The emergency drain bypass is provided with a third drain valve and a fourth drain valve.
[0006] As a preferred embodiment of the present invention, the high-pressure heater includes a first high-pressure heater, a second high-pressure heater and a third high-pressure heater. A first main regulating drain adjustment gate is provided on the pipeline between the first high-pressure heater and the second high-pressure heater, a second main regulating drain adjustment gate is provided on the pipeline between the second high-pressure heater and the third high-pressure heater, and a third main regulating drain adjustment gate is provided between the third high-pressure heater and the deaerator.
[0007] As a preferred solution of the present invention, the first drain valve is a manual valve, and the second drain valve is an electric valve.
[0008] As a preferred solution of the present utility model, the third drain valve is a manual valve, and the fourth drain valve is a manual valve.
[0009] As a preferred solution of the present invention, it also includes main feed water. The first high-pressure heater, the second high-pressure heater and the third high-pressure heater are all provided with a main feed water inlet. The main feed water is transported to the boiler through a pipeline in sequence with the third high-pressure heater, the second high-pressure heater and the first high-pressure heater.
[0010] The utility model provides a steam turbine high-pressure heater drain system for a power plant. Compared with the prior art, the beneficial effects are:
[0011] In operation, when the emergency drain main line is in full open state and still cannot meet the drainage requirements, the emergency drain bypass can be manually opened and appropriately used as auxiliary drain. Among them, the third drain valve is used as a shut-off valve, and the third drain valve is kept in full open state when the emergency drain bypass assists in draining. The fourth drain valve is only used as a regulating valve. The opening of the fourth drain valve is adjusted according to the required drainage volume, and then the position of the high-pressure heater is adjusted to ensure that the water level of the high-pressure heater is controlled within the safe water level range; therefore, through the setting of the emergency drain bypass, the controllability of the high-pressure heater water level can be better guaranteed, and the safe operation of the equipment can be effectively guaranteed. Therefore, there is no need to replace imported spare parts, and there is no need to replace the high-pressure heater, which solves the problem of difficult and expensive procurement of imported spare parts, greatly reduces maintenance costs, and has the advantages of high feasibility and obvious benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings of the embodiments are briefly introduced below.
[0013] Figure 1 The utility model is a structural schematic diagram of a steam turbine high-pressure heater drain system for a power plant provided by an embodiment of the present invention.
[0014] Markings in the figure:
[0015] High-pressure heater 1; first high-pressure heater 101; second high-pressure heater 102; third high-pressure heater 103; emergency drain main line 2; emergency drain bypass line 3; accident expansion tank 4; first drain valve 5; second drain valve 6; third drain valve 7; fourth drain valve 8; first main drain adjustment gate 9; second main drain adjustment gate 10; third main drain adjustment gate 11. DETAILED DESCRIPTION
[0016] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.
[0017] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.
[0018] like Figure 1 As shown, the preferred embodiment of the present invention provides a power plant steam turbine high-pressure heater drain system, which includes multiple high-pressure heaters 1, a critical drain main line 2, a critical drain bypass 3 and an accident expansion tank 4. The first high-pressure heater 1 is connected to the steam turbine, and the multiple high-pressure heaters 1 are connected in sequence through pipelines. The last high-pressure heater is connected to the deaerator through a pipeline. The multiple high-pressure heaters 1 are all connected to the critical drain main line 2 and the critical drain bypass 3. The high-pressure heaters The heat exchanger 1 is provided with a main drain outlet and an emergency drain outlet, one end of the emergency drain main line 2 is connected to the main drain outlet, and the other end of the emergency drain main line 2 is connected to the accident expansion tank 4, and the emergency drain main line 2 is provided with a first drain valve 5 and a second drain valve 6, one end of the emergency drain bypass 3 is connected to the emergency drain outlet, and the other end of the emergency drain bypass 3 is connected to the accident expansion tank 4, and the emergency drain bypass 3 is provided with a third drain valve 7 and a fourth drain valve 8.
[0019] In operation, when the emergency drain main line 2 is in a fully open state but still cannot meet the draining requirements, the emergency drain bypass 3 can be manually opened and appropriately used as an auxiliary drain. The third drain valve 7 is used as a shut-off valve, and the third drain valve 7 is kept in a fully open state when the emergency drain bypass 3 assists in draining. The fourth drain valve 8 is only used as a regulating valve. The opening of the fourth drain valve 8 is adjusted according to the required draining volume, and then the position of the high-pressure heater is adjusted to ensure that the water level of the high-pressure heater is controlled within a safe water level range. Therefore, through the setting of the emergency drain bypass 3, the controllability of the water level of the high-pressure heater can be better guaranteed, and the safe operation of the equipment can be effectively guaranteed. Therefore, there is no need to replace imported spare parts, and there is no need to replace the high-pressure heater, which solves the problem of difficult and expensive procurement of imported spare parts, greatly reduces maintenance costs, and has the advantages of high feasibility and obvious benefits.
[0020] Exemplarily, the high-pressure heater includes a first high-pressure heater 101, a second high-pressure heater 102 and a third high-pressure heater 103. A first main regulating drain adjustment gate 9 is provided on the pipeline between the first high-pressure heater 101 and the second high-pressure heater 102, a second main regulating drain adjustment gate 10 is provided on the pipeline between the second high-pressure heater 102 and the third high-pressure heater 103, and a third main regulating drain adjustment gate 11 is provided between the third high-pressure heater 103 and the deaerator.
[0021] In this embodiment, the first drain valve 5 is a manual valve, the second drain valve 6 is an electric valve, the third drain valve 7 is a manual valve, and the fourth drain valve 8 is a manual valve. Therefore, when the electric valve fails, the manual valve can be used to adjust the emergency drain branch or the emergency drain bypass 3 to avoid failure of the entire emergency drain branch or the emergency drain bypass 3, ensuring that the water level of the high-pressure heater is controlled within the safe water level range.
[0022] Illustratively, a power plant steam turbine high-pressure heater drain system also includes main feed water, and the first high-pressure heater 101, the second high-pressure heater 102 and the third high-pressure heater 103 are each provided with a main feed water inlet, and the main feed water is transported to the boiler through a pipeline in sequence with the third high-pressure heater 103, the second high-pressure heater 102 and the first high-pressure heater 101.
[0023] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0024] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.
Claims
1. A steam turbine high-pressure heater drain system for a power plant, characterized in that: It includes multiple high-pressure heaters, emergency drain main lines, emergency drain bypasses and accident expansion tanks. The first high-pressure heater is connected to the steam turbine, and the multiple high-pressure heaters are connected in sequence through pipelines. The last high-pressure heater is connected to the deaerator through a pipeline. The multiple high-pressure heaters are all connected to the emergency drain main line and the emergency drain bypass. The high-pressure heaters are provided with a main drain port and an emergency drain port. One end of the emergency drain main line is connected to the main drain port, and the other end of the emergency drain main line is connected to the accident expansion tank. The emergency drain main line is provided with a first drain valve and a second drain valve, one end of the emergency drain bypass is connected to the emergency drain port, and the other end of the emergency drain bypass is connected to the accident expansion tank. The emergency drain bypass is provided with a third drain valve and a fourth drain valve.
2. A power plant steam turbine high-pressure heater drain system according to claim 1, characterized in that: The high-pressure heater includes a first high-pressure heater, a second high-pressure heater and a third high-pressure heater. A first main regulating drain adjustment gate is provided on the pipeline between the first high-pressure heater and the second high-pressure heater, a second main regulating drain adjustment gate is provided on the pipeline between the second high-pressure heater and the third high-pressure heater, and a third main regulating drain adjustment gate is provided between the third high-pressure heater and the deaerator.
3. The power plant steam turbine high-pressure heater drain system according to claim 1, characterized in that: The first drain valve is a manual valve, and the second drain valve is an electric valve.
4. A power plant steam turbine high-pressure heater drain system according to claim 1, characterized in that: The third drain valve is a manual valve, and the fourth drain valve is a manual valve.
5. The power plant steam turbine high-pressure heater drain system according to claim 2, characterized in that: It also includes main feed water. The first high-pressure heater, the second high-pressure heater and the third high-pressure heater are all provided with a main feed water inlet. The main feed water is transported to the boiler through a pipeline in sequence with the third high-pressure heater, the second high-pressure heater and the first high-pressure heater.