High-pressure heater accident drainage pneumatic control valve

Abstract

The utility model discloses a high-pressure heater accident drainage pneumatic control valve which comprises a compressed air inlet assembly, a three-way air inlet valve, an air cylinder position retaining valve, a pneumatic valve air cylinder, a positioner, a first electromagnetic valve and a second electromagnetic valve. The compressed air inlet assembly is connected with the air inlet pipe; the compressed air inlet assembly is connected with the air outlet pipe; the air outlet pipe is connected with the three-way air inlet valve; the three-way air inlet valve is connected with the cylinder position retaining valve through a pipeline; the three-way air inlet valve is connected with the positioner through a pipeline; the positioner is connected with the pneumatic door cylinder; the positioner is connected with the first electromagnetic valve through a pipeline; the first electromagnetic valve is communicated with the outside atmosphere; the first electromagnetic valve is connected with the air cylinder position retaining valve through a pipeline; the cylinder position retaining valve is connected with the pneumatic door cylinder through a pipeline; the pneumatic door cylinder is connected with the second electromagnetic valve through a pipeline; and the second electromagnetic valve is communicated with the outside atmosphere. According to the high-pressure heater accident drainage pneumatic control valve, the opening speed of the high-pressure heater accident drainage pneumatic control valve is increased, and the response time is shortened.

Description

Technical Field

[0001] The utility model relates to the technical field of electric power engineering, in particular to a high pressure emergency drain pneumatic regulating valve. Background Art

[0002] The emergency drain regulating valve of the high-pressure heating system of the steam turbine (hereinafter referred to as the large unit) is a single-acting pneumatic regulating valve.

[0003] High-pressure booster drain includes normal drain and emergency drain. During normal operation, the high-pressure booster emergency drain regulating valve of the large machine is in the closed state, and the high-pressure booster normal drain regulating valve is in the automatically opened state. The drain adopts the step-by-step gravity flow method to maintain the high-pressure booster liquid level within the normal range. When the load fluctuates greatly or abnormal conditions such as the failure of the high-pressure booster normal drain regulating valve occur, causing the high-pressure booster liquid level to rise to the high liquid level, the high-pressure booster emergency drain regulating valve opens. The procedure to be executed when opening is: when the cylinder exhausts to a pressure lower than the regulating valve spring pressure, the high-pressure booster emergency drain regulating valve automatically opens. The time from the high water level to the high-pressure booster emergency drain regulating valve opening is about 10 seconds.

[0004] The above scheme has the following defects during implementation:

[0005] (1) Due to the small volume of the high-pressure heater, the water level rises rapidly, which can easily lead to the high-pressure heater being disconnected;

[0006] (2) The response time of the high pressure heater emergency drain regulating valve is long, which is not enough to maintain the high pressure heater water level within the normal range;

[0007] (3) After the high-pressure heater is disconnected, if the electric exhaust valve or check valve on the steam side of the high-pressure heater does not operate reliably or is not closed tightly, the water level will continue to rise, and there is a risk of water entering the turbine, which will directly endanger the safe operation of the turbine. Utility Model Content

[0008] In view of this, the utility model proposes a pneumatic regulating valve for high pressure emergency drain.

[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0010] A pneumatic regulating valve for high pressure emergency drain, comprising a compressed air intake assembly, a three-way intake valve, a cylinder position-keeping valve, a pneumatic valve cylinder, a positioner, a first solenoid valve and a second solenoid valve;

[0011] The compressed air intake assembly is connected to the air intake pipe; the compressed air intake assembly is connected to the air outlet pipe;

[0012] The air outlet pipe is connected to the three-way air inlet valve; the three-way air inlet valve is connected to the cylinder position-keeping valve through a pipeline; the three-way air inlet valve is connected to the positioner through a pipeline;

[0013] The positioner and the pneumatic door cylinder are connected to each other;

[0014] The positioner is connected to the first solenoid valve through a pipeline; the first solenoid valve is connected to the outside atmosphere; the first solenoid valve is connected to the cylinder position-keeping valve through a pipeline;

[0015] The cylinder position-keeping valve is connected to the pneumatic door cylinder through a pipeline; the pneumatic door cylinder is connected to the second solenoid valve through a pipeline;

[0016] The second solenoid valve is connected to the outside atmosphere.

[0017] Furthermore, the compressed air intake assembly includes a compressed air intake manual door and a compressed air filter.

[0018] Furthermore, the manual compressed air intake door is connected to the intake pipe; the manual compressed air intake door is connected to the outlet pipe.

[0019] Furthermore, the compressed air filter is embedded in the air outlet pipe.

[0020] Compared with the existing technology, the beneficial effects of the utility model are:

[0021] (1) To enable timely response when the high pressure heater emergency drain regulating valve is opened, which is conducive to maintaining the high pressure heater water level;

[0022] (2) Avoid abnormal conditions of high-pressure heater disconnection caused by untimely opening of the high-pressure heater emergency drain regulating valve;

[0023] (3) Reduce the risk of water ingress into the turbine;

[0024] (4) Avoid abnormal operating conditions such as overload and boiler overheating caused by high-pressure heater disconnection;

[0025] (5) Prevent the high-pressure booster from being disconnected and the accident from further expansion due to improper handling by the operating personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of the high pressure emergency drain pneumatic regulating valve during exhaust provided by the embodiment of the utility model;

[0027] Figure 2 A schematic diagram of the structure of the high pressure emergency drain pneumatic regulating valve during air intake provided by an embodiment of the utility model;

[0028] In the figure: 1. Manual door for compressed air intake; 2. Compressed air filter; 3. Three-way intake valve; 4. Cylinder retaining valve; 5. Pneumatic door cylinder; 6. Positioner; 7. First solenoid valve; 8. Second solenoid valve; 9. Inlet pipe; 10. Outlet pipe; 11. Positioner exhaust port. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does 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. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Example:

[0033] like Figure 1-2 As shown, a high pressure emergency drain pneumatic regulating valve includes a compressed air intake assembly, a three-way intake valve 3, a cylinder retaining valve 4, a pneumatic door cylinder 5, a positioner 6, a first solenoid valve 7 and a second solenoid valve 8.

[0034] The compressed air intake assembly comprises a compressed air intake manual door 1 and a compressed air filter 2. The compressed air intake manual door 1 is a manual valve.

[0035] The compressed air inlet manual door 1 is connected to the inlet pipe 9; the compressed air inlet manual door 1 is connected to the outlet pipe 10. The compressed air filter 2 is embedded in the outlet pipe 10.

[0036] The air outlet pipe 10 is connected to the three-way air intake valve 3; the three-way air intake valve 3 is connected to the cylinder position-keeping valve 4 through a pipeline; the three-way air intake valve 3 is connected to the positioner 6 through a pipeline.

[0037] like Figure 1-2 As shown, in the cylinder position-keeping valve 4, A and C are air chambers and B is the position-keeping valve core.

[0038] The positioner 6 and the pneumatic door cylinder 5 are connected to each other. Figure 1-2 The door rod is located between the middle pneumatic door cylinder 5 and the positioner 6. The positioner 6 is connected to the first electromagnetic valve 7 through a pipeline; the first electromagnetic valve 7 is connected to the outside atmosphere; the first electromagnetic valve 7 is connected to the cylinder position-keeping valve 4 through a pipeline. The positioner 6 has a positioner exhaust port 11.

[0039] The cylinder retaining valve 4 is connected to the pneumatic door cylinder 5 through a pipeline; the pneumatic door cylinder 5 is connected to the second solenoid valve 8 through a pipeline.

[0040] The second solenoid valve 8 is connected to the outside atmosphere.

[0041] Working principle:

[0042] Abnormal conditions such as large load fluctuations or failure of the normal drain regulating valve of the high-pressure heater cause the high-pressure heater liquid level to rise to a high liquid level. When the high liquid level triggers the high-pressure heater emergency drain pneumatic regulating valve, the emergency drain regulating valve is triggered or the DCS inputs the emergency regulating valve command, the high-pressure heater emergency drain pneumatic regulating valve releases pressure through the first and second routes at the same time. When the pressure is released to the point where the regulating valve starts to act, the second solenoid valve 8 of the first route is closed, and the second route continues to adjust the pressure relief;

[0043] The first pressure relief route is: pressure relief is performed through the second solenoid valve 8, and the exhaust process of compressed air is that the pneumatic door cylinder 5 flows to the second solenoid valve 8, and is discharged to the atmosphere by the second solenoid valve 8 for pressure relief;

[0044] The second pressure relief route is: pressure relief is carried out through the positioner exhaust port 11, and the exhaust process of compressed air is as follows: it flows from the pneumatic door cylinder to the cylinder retaining valve 4, the cylinder retaining valve 4 flows to the first solenoid valve 7, the first solenoid valve 7 flows to the positioner 6, and the pressure is discharged and relieved from the positioner exhaust port 11.

[0045] In this embodiment, the exhaust pipe of the high pressure emergency drain valve cylinder is thickened to increase the exhaust volume and shorten the exhaust time. Taking into account the exhaust speed and the bearing safety range of the cylinder diaphragm, the original 8mm outer diameter pipe is replaced with a 12mm outer diameter pipe.

[0046] In this embodiment, the pneumatic valve cylinder 5 of the high pressure emergency drain pneumatic regulating valve is independently provided with an exhaust pipe controlled by a solenoid valve: a second solenoid valve 8.

[0047] The pneumatic regulating valve for the high-pressure heater emergency drain provided in this embodiment has a faster opening speed and a shorter response time, which is beneficial for controlling the water level of the high-pressure heater within a normal range, preventing the occurrence of high-pressure heater group disconnection accidents, greatly reducing the risk of water ingress to the turbine, and preventing equipment damage.

[0048] The above are only preferred specific implementation methods of the utility model, but the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model, who makes equivalent replacements or changes based on the technical scheme and utility model concept of the utility model, should be covered by the protection scope of the utility model.

Claims

1. A pneumatic regulating valve for high pressure emergency drain, characterized in that: It comprises a compressed air intake assembly, a three-way intake valve (3), a cylinder position-keeping valve (4), a pneumatic door cylinder (5), a positioner (6), a first solenoid valve (7) and a second solenoid valve (8); The compressed air intake assembly is connected to an air intake pipe (9); the compressed air intake assembly is connected to an air outlet pipe (10); The air outlet pipe (10) is connected to the three-way air inlet valve (3); the three-way air inlet valve (3) is connected to the cylinder position-keeping valve (4) through a pipeline; the three-way air inlet valve (3) is connected to the positioner (6) through a pipeline; The positioner (6) and the pneumatic door cylinder (5) are connected to each other; The positioner (6) is connected to the first electromagnetic valve (7) through a pipeline; the first electromagnetic valve (7) is connected to the outside atmosphere; the first electromagnetic valve (7) is connected to the cylinder position-keeping valve (4) through a pipeline; The cylinder retaining valve (4) is connected to the pneumatic valve cylinder (5) via a pipeline; the pneumatic valve cylinder (5) is connected to the second solenoid valve (8) via a pipeline; The second solenoid valve (8) is connected to the outside atmosphere.

2. The pneumatic regulating valve for emergency drain of high pressure heater according to claim 1 is characterized in that: The compressed air intake assembly comprises a compressed air intake manual door (1) and a compressed air filter (2).

3. The pneumatic regulating valve for emergency drain of high pressure heater according to claim 2 is characterized in that: The compressed air inlet manual door (1) is connected to the inlet pipe (9); the compressed air inlet manual door (1) is connected to the outlet pipe (10).

4. The pneumatic regulating valve for emergency drain of high pressure heater according to claim 3 is characterized in that: The compressed air filter (2) is embedded in the interior of the air outlet pipe (10).

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