JP2001246202A - Degassing device sealing vapor system installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a degassing device sealing vapor system installation of thermal power and atomic power plants to simplify the sealing vapor system at a time of the stop of the plants. SOLUTION: A line having an on-off valve 3, a heated vapor pressure control valve 4 and an on-off motor-operated valve 5 is connected to a degassing device 1 from an auxiliary vapor line 60. A bypass line 11 is provided to the on-off motor-operated valve 5, and an on-off piston valve 12 and an orifice 13 are provided to the bypass line 11. A control unit 10 takes in a pressure signal in the degassing device 1 from a pressure sensor 9 at times of start and stop and opens the on-off valve 5 and sets the heated vapor pressure control valve 4 to a predetermined open degree and opens the on-off piston valve 12 to supply vapor to the degassing device 1 through the orifice 13 to hold the pressure in the degassing device 1 to atmospheric pressure or more. A seal vapor line becomes simple constitution consisting of the on-off valve 12 and the orifice 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degasifier seal steam system facility for a thermal and nuclear power plant, which simplifies the seal steam system and ensures the function of the seal.

[0002]

2. Description of the Related Art FIG. 4 is a view showing a system of a deaerator in a thermal power plant and a nuclear power plant. Reference numeral 1 denotes a deaerator which removes gas such as air from heating water from a low-pressure heater and sends the gas to a high-pressure heater. It is a device to send. The water condensed by the condenser 40 is sent to the low-pressure heaters 42 a and 42 b by the condensing pump 41 and is heated to be heated water. The heated water from the low-pressure heater 42 b is sent from the pipe 2 to the deaerator 1. In the deaerator, the condensate is brought into direct contact with the steam from the steam turbine outlet, and the condensate is raised to the saturation temperature of the pressure inside the deaerator to remove non-condensable gas such as air. The heated water degassed by the deaerator 1 is sent to the high-pressure heaters 44a and 44b by the pump 43 and becomes high-temperature water supply.
Sent to the boiler.

FIG. 5 is a diagram showing details of a heating steam system and a sealing steam system of the deaerator described above. In the figure, a heating steam line to which heating steam is sent from an auxiliary steam line 60 via an on-off valve 3, a heating steam pressure control valve 4, and an on-off electric valve 5 is connected to a pipe 2 of the deaerator 1.
Further, the on-off valve 6, the seal steam pressure control valve 7, and the on-off piston valve 8 are connected to the pipe 2 of the deaerator 1 through the same auxiliary steam line 60.
A seal steam line to which the seal steam is supplied is connected. The opening and closing operations of the valves 3, 4, 5, 6, 7, and 8 and the opening of the valves are controlled by the control device 10, respectively. The above-described heated steam line supplies steam from the auxiliary steam line 60 at the start of the plant, at a low load, or when the load is suddenly reduced, and backs up the bleed air from the steam turbine. In order to prevent the atmosphere from flowing into the deaerator tank and increasing the amount of dissolved oxygen in the tank to oxidize the system and generate rust, deaeration is performed based on a pressure signal from the pressure sensor 9. This is a line for introducing steam into the vessel 1 and keeping the inside of the deaerator 1 at atmospheric pressure or higher.

[0004] In the steam system of the deaerator having the above configuration, the amount of steam in the seal steam line is considerably smaller than the amount of steam in the auxiliary heating steam line, and the amount of auxiliary steam is several tens times that of seal steam. When heating steam is supplied from the auxiliary steam line, the on-off valve 5 is simultaneously opened according to a command from the control device 10, the heating steam pressure control valve 4 is set to a predetermined opening degree, and steam is supplied for a predetermined time. Similarly, when the seal steam is supplied, the control device 10 detects the stop of the unit, closes the opening / closing piston valve 8, sets the seal steam pressure control valve 7 to a predetermined opening, and removes the seal steam. The gas is supplied into the gasifier 1, and the pressure signal of the pressure sensor 9 in the deaerator is maintained so that the atmospheric pressure is equal to or higher than the atmospheric pressure.

[0005] It is conceivable to substitute the seal steam line by controlling the opening degree thereof by the pressure control valve 4 of the heating steam line. However, as described above, the sealing steam amount is small, and is 1/10 or less of the heating steam amount. Since the opening of the large-volume pressure control valve 4 is controlled as a small opening, the valve cannot be accurately controlled in a slightly open state, resulting in an on / off operation, which is not preferable. Therefore, conventionally, a sealing steam line was provided separately from the heating steam line, and an on-off valve 6, a pressure control valve 7, and an on-off piston valve 8 were required.

[0006]

As described above, in the conventional heating steam system of a deaerator, a deaerator heating steam line and a deaerator sealing steam line are respectively connected to an auxiliary steam line for exclusive use. Steam is supplied to the porcelain, and the steam system of the apparatus becomes complicated, and simplification of the system has been desired. However, if an attempt is made to supply the seal steam to a heated steam line having a large steam flow rate, the pressure control valve of the heated steam line is turned on / off in a slightly opened state as described above, and noise is generated and the valve is not operated. There is a problem that the reliability of the device is impaired.

Accordingly, the present invention provides a deaerator seal steam system facility which simplifies the seal steam line of the deaerator and provides a simple seal line to perform the same deaerator seal function as the conventional one. The task was to do.

[0008]

The present invention provides the following means (1) to (3) to solve the above-mentioned problems.

(1) A heating steam system having a pressure control valve for supplying heating steam from the auxiliary steam line to the deaerator when the plant is started or stopped, and a sealing steam system for supplying sealing steam. In the steam system equipment for a deaerator, the seal steam system includes a bypass line arranged in parallel with the heating steam system on the downstream side of the pressure control valve of the heating steam system. And an orifice connected in series.

(2) A heating steam system having a pressure control valve for supplying heating steam from the auxiliary steam line to the deaerator when the plant is started or stopped, and a sealing steam system for supplying sealing steam. In the steam system equipment for a deaerator, the seal steam system is provided in parallel with the heating steam system, and an outlet end is opened into a liquid phase in the deaerator via an on-off piston valve. And deaerator seal steam system equipment.

(3) The outlet end of the seal steam system is connected to a downcomer of the deaerator instead of opening into the liquid phase of the deaerator. Deaerator seal steam system equipment.

In (1) of the present invention, when the plant is stopped, the inside of the deaerator is set to a pressure higher than the atmospheric pressure to prevent the inhalation of the atmosphere and seal with steam so that dissolved oxygen does not increase and rust is generated in the system. Things are going on. In the seal steam system, open the pressure control valve of the heating steam system from the auxiliary steam line, flow steam to the bypass line, open the bypass line opening and closing piston valve, supply a predetermined amount of steam from the orifice to the deaerator, and The pressure inside is maintained above atmospheric pressure. The supplied seal steam is smaller than the heating steam amount, but even if the pressure control valve of the heating steam system is opened, the required steam amount set at the orifice is stably supplied from the bypass line to the deaerator, The pressure control valve of the heating steam system can also supply steam without fluctuation. (1) of the present invention
In this case, since the pressure control valve of the heating steam system is also used for supplying the sealing steam, the sealing steam system is simplified as compared with the related art.

In (2) of the present invention, the amount of the seal steam is set by the on-off valve of the seal steam system, and the outlet end of the seal steam is opened in the liquid phase in the deaerator. Independently of the heating steam system, the line passes through only the opening and closing piston valve, and is supplied to the tank via the liquid phase of the deaerator, so that the inside of the deaerator can be maintained at atmospheric pressure or higher. Therefore, the seal steam is supplied in a simple seal steam system without using the heating steam system.

In (3) of the present invention, since the outlet end of the seal steam system is connected to the downcomer, the steam is supplied from the auxiliary steam line to the on-off valve independently of the heating steam system as in the above (2) invention. It is supplied to the downcomer through the only line, and is supplied from the downcomer through the liquid phase into the tank to maintain the inside of the deaerator at or above atmospheric pressure. Therefore, the same effect as that of the invention (2) can be obtained with a simple seal steam system.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a system diagram of a deaerator seal steam system facility according to a first embodiment of the present invention. In the figure, reference numerals 1 to 5 and 9, 10, and 60 have the same functions as those of the conventional example shown in FIG. 5, and are denoted by the same reference numerals and are described as they are. , Reference numerals 11, 12, and 13, which will be described in detail below.

In FIG. 1, a heating steam system including an on-off valve 3, a heating steam pressure control valve 4, and an on-off motorized valve 5 is provided from an auxiliary steam line 60 as in the prior art.
Steam can be supplied to Reference numeral 11 denotes a bypass line which includes an opening / closing piston valve 12 and an orifice 13 and is arranged in parallel with the opening / closing electric valve 5 of the heating steam system. This configuration replaces the conventional line including the on-off valve 6, the pressure control valve 7, and the on-off piston valve 8 shown in FIG. 5, and the system is simplified.

In the first embodiment of the above configuration, when supplying the seal vapor to the deaerator 1, the control device 10 detects the stop of the unit, and detects the stop of the unit and outputs the pressure from the pressure sensor 9 to the inside of the deaerator 1. The pressure signal is fetched, the opening of the pressure control valve 4 is set to a predetermined steam flow rate so that the pressure of the deaerator 1 becomes equal to or higher than the atmospheric pressure, and the opening and closing piston valve 12 is controlled to open. The orifice 13 is selected so that the required seal vapor flow rate is obtained.

By such control, the auxiliary steam line 60
The steam flows from the opening set by the pressure control valve 4 into the bypass line 11, reaches a constant flow rate in a constant flow path set by the orifice 13, passes through the pipe 2, and enters a predetermined position into the deaerator 1. The steam is supplied for a period of time to maintain the inside of the deaerator 1 at or above the atmospheric pressure. In this case, since the flow rate set by the orifice 13 is a constant amount, the flow rate of the pressure control valve 4 also has a small fluctuation, the ON / OFF operation is suppressed, and the seal steam can be supplied at a stable steam flow rate. .

FIG. 2 is a system diagram of a deaerator seal steam system facility according to a second embodiment of the present invention. In the figure, a portion different from the first embodiment is a portion provided with a pipe 21 and an on-off piston valve 20 instead of the bypass line 11, the on-off piston valve 12, and the orifice 13 shown in FIG. It is the same as FIG.

In FIG. 2, a pipe 21 is provided from the auxiliary steam line 60 via an on-off piston valve 20,
The end of the pipe 21 penetrates through the deaerator 1 and opens into the liquid phase on the bottom surface of the deaerator 1. In the second embodiment having such a configuration, when supplying the seal steam, the control device 10 takes in the pressure signal in the deaerator 1 from the pressure sensor 9 and the pressure in the deaerator 1 becomes large. The on-off piston valve 20 is opened for a predetermined time so that the pressure becomes equal to or higher than the atmospheric pressure, and steam is directly injected from the pipe 21 into the liquid phase in the deaerator 1. The introduced steam heats the inside of the deaerator liquid phase and maintains the inside of the deaerator 1 at or above atmospheric pressure. The steam flow rate when the opening / closing piston valve 20 is opened should be selected so as to have a necessary capacity for the seal steam flow rate.

In the second embodiment, the supply of the seal steam is performed by opening and closing only the opening and closing piston valve 20 without operating all of the on-off valve 3, the pressure control valve 4, and the on-off electric valve 5 of the heating steam line. Since the necessary sealing steam is supplied, the same effect as that of the first embodiment can be obtained with a simple configuration.

FIG. 3 is a system diagram of a deaerator seal steam system facility according to a third embodiment of the present invention. In the figure, a portion different from the first embodiment is a portion provided with a pipe 31 and an on-off piston valve 30 instead of the bypass line 11, the on-off piston valve 12, and the orifice 13 shown in FIG. Further, as compared with the second embodiment shown in FIG. 2, the tip of the pipe 21 is opened in the liquid phase in the deaerator 1 in the second embodiment, but in the third embodiment, Piping 31
Is connected to the downcomer pipe 50 of the deaerator 1.

According to the third embodiment of the above configuration, when supplying the seal steam, the control device 10 takes in the pressure signal in the deaerator 1 from the pressure sensor 9 and The open / close piston valve 30 is opened for a predetermined time so that the pressure is equal to or higher than the atmospheric pressure, and steam is supplied from the pipe 31 to the downcomer 50. The steam heats the downcomer 50 and the condenser in the deaerator liquid phase to maintain the inside of the deaerator 1 at or above atmospheric pressure. The capacity of the open / close piston valve 30 is selected so as to obtain a steam flow required for sealing.

In the third embodiment, the supply of the seal steam is performed by opening and closing only the on-off piston valve 30 without operating all of the on-off valve 3, the pressure control valve 4, and the on-off electric valve 5 of the heating steam line. Since the necessary sealing steam is supplied, the first embodiment and the second embodiment can be simply configured.
The same effect as in the embodiment can be obtained.

[0025]

The deaerator seal steam system of the present invention has the following features.
(1) A heating steam system having a pressure control valve for supplying heating steam from the auxiliary steam line to the deaerator when the plant is started or stopped or when the load is rapidly reduced, and a seal steam for supplying the seal steam. In the steam system equipment of a deaerator having a system, the seal steam system includes a bypass line arranged in parallel with the heating steam system on the downstream side of the pressure control valve of the heating steam system. An on-off valve and an orifice are connected in series and provided. With such a configuration, in the seal steam system, the pressure control valve of the heating steam system is opened from the auxiliary steam line to flow steam to the bypass line, and the opening / closing piston valve of the bypass line is opened to send a predetermined amount of steam from the orifice to the deaerator. Supply and keep the inside of the deaerator above atmospheric pressure. The supplied seal steam is smaller than the heating steam amount, but even if the pressure control valve of the heating steam system is opened, the required steam amount set at the orifice is stably supplied from the bypass line to the deaerator, The pressure control valve of the heating steam system can also supply steam without fluctuation. (1) of the present invention
In this case, since the pressure control valve of the heating steam system is also used for supplying the sealing steam, the sealing steam system is simplified as compared with the related art.

[0026] According to a second aspect of the present invention, in the steam system equipment having the same configuration as the premise of the first aspect, the seal steam system is provided in parallel with the heating steam system, and an outlet end is provided via an on-off piston valve. It is characterized in that it opens into the liquid phase in the deaerator. With such a configuration, the seal steam heats the liquid phase of the deaerator from the auxiliary steam line, independently of the heating steam system, through a line including only the opening and closing piston valve, and maintains the inside of the deaerator at or above the atmospheric pressure. be able to. Therefore,
A simple seal steam system that supplies seal steam without using a heated steam system.

In (3) of the present invention, since the outlet end of the seal steam system is connected to the downcomer, the steam is supplied from the auxiliary steam line to the on-off valve independently of the heating steam system as in the above (2) invention. It is supplied to the downcomer through the only line, and heats the downcomer and the condenser of the deaerator to maintain the inside of the deaerator at or above atmospheric pressure. Therefore, the same effect as that of the invention (2) can be obtained with a simple seal steam system.

[Brief description of the drawings]

FIG. 1 is a system diagram of a deaerator seal steam system facility according to a first embodiment of the present invention.

FIG. 2 is a system diagram of a deaerator seal steam system facility according to a second embodiment of the present invention.

FIG. 3 is a system diagram of a deaerator seal steam system facility according to a third embodiment of the present invention.

FIG. 4 is a general system diagram of a deaerator in a thermal power plant.

FIG. 5 is a system diagram of a conventional deaerator seal steam system facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deaerator 2, 21, 31 Piping 3 On-off valve 4 Heating steam pressure control valve 5 On-off electric valve 9 Pressure sensor 10 Control device 11 Bypass line 12, 20, 30 On-off piston valve 13 Orifice 50 Downcomer 60 Auxiliary steam line

Claims (3)

[Claims] 1. A heating steam system having a pressure control valve for supplying heating steam from the auxiliary steam line to the deaerator when starting or stopping the plant, and a degassing system having a sealing steam system for supplying sealing steam. In the steam system equipment of the porcelain, the seal steam system includes a bypass line arranged in parallel with the heating steam system on the downstream side of the pressure control valve of the heating steam system, and an on-off valve and an orifice are provided in the bypass line. And a degasser seal steam system facility, which are connected in series. 2. A heating steam system having a pressure control valve for supplying heating steam from the auxiliary steam line to the deaerator when the plant is started or stopped, and a degassing system having a sealing steam system for supplying sealing steam. In the steam system equipment for a porcelain, the seal steam system is provided in parallel with the heating steam system, and an outlet end is opened into a liquid phase in the deaerator via an on-off valve. Deaerator seal steam system equipment. 3. The method according to claim 2, wherein the outlet end of the seal steam system is connected to a downcomer of the deaerator instead of opening into the liquid phase of the deaerator. Deaerator seal steam system equipment.