JPH094989A - Condensed water deaeration device - Google Patents

Abstract

PURPOSE: To shorten a starting time by a method wherein a water storing tank is separately arranged from a hot well of a condensor, the water storing tank is not damaged in vacuum also during a stopped state of a plant, water in the tank is kept at its deaerated state and the deaerated water is in the water storing tank is recirculated when a recirculation is carried out. CONSTITUTION: When a plant is stopped in its operation, an air vent valve 14a is opened so as to break vacuum in a condensor 1. However, air vent valves 14b, 14c are kept closed and water in the water storing tank 3 is kept at its deaerated state. When a re-energization is carried out, a condensing valve 8 between a hot well 14 and a low pressure water feeding pump 5 is closed, a condensing valve 9 between the water storing tank 3 and the low pressure water feeding pump 5 is opened, an adjusting valve 11 between an energizing deaeration device 2 and the water storing tank 3 is opened, the low pressure water feeding pump 5 is energized so as to perform a condensed water re- circulating operation. With such an arrangement as above, it is possible to re-circulate the deaerated water in the water storing tank during the re- energization time and to perform an energization, resulting in that an energization time of the plant is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment for degassing condensate when starting a steam plant.

[0002]

2. Description of the Related Art If a non-condensable gas such as oxygen is dissolved in boiler feed water, electrical or chemical corrosion will occur in the boiler and auxiliary equipment, which must be removed. However, when the vacuum of the condenser is broken when the plant is stopped, the condensate in the condenser comes into contact with air and oxygen (O
₂ ) Be rich. Therefore, at the time of restart, it is necessary to sufficiently degas the condensate and supply it to the boiler.

FIG. 3 is a system diagram showing an example of a conventional condensate degassing system for startup. The deaerator (2) for start-up is integrally attached to the condenser (1), and the non-deaerated water in the hot well (4) after breaking the vacuum is removed by the low-pressure feed pump (5). ) To degas the condensate. In FIG. 3, (8), (13) and (18) are condensate valves, (11) is a deaerator water level control valve, and (17) is a condensate recirculation conduit.

[0004]

[Problems to be Solved by the Invention] DSS (Daily Start)
In some cases, it is required to start the plant in a short time and shift to normal operation, such as when the plant is restarted. However, if the condenser was vacuum-disrupted while the plant was stopped, it took time because of degassing at the time of restarting, and it was difficult to start it in the required short time.

[0005]

In order to solve the above-mentioned conventional problems, the present inventor has found that in a steam plant having a condenser, an airtight water storage tank different from the hot well of the condenser and a start-up are provided. Condensate for forming a water vaporizer and a condenser together with the condenser, and for communicating the bottom of the water storage tank with the outlet of the condenser valve provided in the conduit from the bottom of the hot well to the low pressure feed pump. A conduit with a valve, a conduit with a condensate valve from the outlet of the low-pressure feed pump to the upper part of the starting deaerator through the ground condenser, and from the bottom of the starting deaerator to the water storage tank. The present invention proposes a condensate degassing device, which is provided with a pipe line with a condensate valve reaching the upper part and an air vent valve communicating with the upper part of the water storage tank.

[0006]

Since the present invention has the above-described structure, if the deaerator for start-up and the air vent valves of the water storage tank are kept closed when the plant is stopped, the water in the water storage tank will not come into contact with the air, so Be kept in a good condition.

Therefore, at the time of restart, the condensate valve between the hot well and the low-pressure water supply pump is closed, and the condensate valve between the water storage tank and the low-pressure water supply pump and the condensate valve between the starting deaerator and the water storage tank are opened. Then, the low-pressure water supply pump is started and the condensate recirculation operation is performed. Then, the degree of vacuum in the condenser rises. After the vacuum rise is completed, the condensate valve downstream of the ground condenser is opened to start sending water to the boiler, and the plant is started with the entire water supply system in operation.

As described above, since the degassed water in the water storage tank can be recirculated and restarted at the time of restart, the startup time can be shortened.

[0009]

FIG. 1 is a system diagram showing a condensate degassing apparatus according to an embodiment of the present invention.

The condenser (1) has a starter deaerator (2).
And an airtight water storage tank (3) separate from the hot well (4) of the condenser are integrally mounted. The hot well (4) of the condenser (1) and the water storage tank (3) are
It has a structure that shares condensate at the same level. The capacity of the water storage tank (3) should be about 5 minutes of the rated water supply.

Condensate valve (8) provided in the conduit (6) from the bottom of the hot well (4) to the low pressure feed pump (5).
A conduit (7) for communicating the bottom of the water storage tank (3) is provided at the outlet of the conduit (7), and a condensate valve (9) is provided in this conduit. A condensate valve (18) is also provided in the condensate recirculation line (17) from the outlet of the low-pressure water supply pump (5) to the upper part of the starting deaerator (2) via the gland condenser (12). Further, in the conduit (10) from the bottom of the starting deaerator (2) to the upper part of the water storage tank (3), a condensate valve (11) for adjusting the water level of the starting deaerator (2). Is provided. Further, a condensate valve (13) is provided downstream of the branch portion where the condensate recirculation conduit (17) branches off downstream of the ground condenser (12). By operating each of these valves, the degassed condensate can be isolated.
Further, the condenser (1), the deaerator (2) for starting, and the water storage tank (3) are provided with air vent valves (14a) and (14), respectively.
b) and (14c) are provided. The reference numeral (15)
Is a level controller, and reference numeral (16) is a level switch.

FIG. 2 is a diagram showing a schematic structure of the condenser (1) of this embodiment, and FIG. 2 (a) is a front view of the condenser, and FIG.
2B is a side view of the same, and FIG. 2C is a plan view of the inside of the water storage tank. The condenser (1) has a structure integrated with the starting deaerator (2) and the water storage tank (3). The inside of the water storage tank (3) is partitioned by a partition plate.

When the plant is stopped, the air vent valve (14
Although a) is opened and the inside of the condenser (1) is vacuum-disrupted, the air vent valves (14b) and (14c) are kept closed. Therefore, the water in the hot well (4) comes into contact with air to dissolve oxygen and the like, but the water in the water storage tank (3) is kept in a deaerated state.

At the time of restart, the condensate valve (8) between the hot well (4) and the low pressure feed pump (5) is closed, and the condensate valve (9) between the water storage tank (3) and the low pressure feed pump (5) is closed. ) And the deaerator (2) for starting and the water storage tank (3) between the control valve (11)
Is opened, the low-pressure feed pump (5) is started, and the condensate recirculation operation is performed. Then, the degree of vacuum in the condenser (1) rises. After the vacuum rise is completed, the condensate valve (13) downstream of the ground condenser (12) is opened to start feeding water to the boiler, and the plant is started with all the water supply systems in operation.

Thus, at the time of restart, the water storage tank (3)
The water inside the hot well (4) is shared, that is, the pressures of the two are balanced and the condensate level is kept constant. It can be recirculated and activated, thus reducing activation time.

[0016]

According to the condensate degassing apparatus of the present invention, since the degassed water in the water storage tank can be recirculated and started at the time of restart, the start-up time of the plant can be shortened. Therefore, when the DSS is stopped, there is no need to constantly operate the circulating water pump to maintain the vacuum unlike the conventional case. As a result, the pump power cost can be reduced and an energy-saving plant can be realized.

[Brief description of drawings]

FIG. 1 is a system diagram showing a condensate degassing apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a schematic structure of the condenser of the above embodiment, FIG. 2 (a) is a front view of the condenser, FIG. 2 (b) is a side view thereof, and FIG. c) is a plan view of the inside of the water storage tank.

FIG. 3 is a system diagram showing an example of a conventional condensate degassing system for startup.

[Explanation of symbols]

(1) Condenser (2) Deaerator for start-up (3) Water storage tank (4) Hot well (5) Low-pressure water supply pump (6), (7) Pipe line (8), (9) Condensate valve ( 10) Pipe line (11) Condensation valve (deaerator water level control valve) (12) Ground condenser (13) Condensation valve (14a), (14b), (14c) Air vent valve (15) Level controller (16) ) Level switch (17) Condensate recirculation line (18) Condensate valve

Claims (1)

[Claims] 1. In a steam plant having a condenser,
An airtight water storage tank different from the hot well of the condenser and a deaerator for starting are integrally formed with the condenser, and are provided in a pipe line from the bottom of the hot well to the low pressure feed pump. A conduit with a condensate valve that connects the bottom of the water storage tank to the outlet of the condensate valve, and a condensate valve from the outlet of the low-pressure feed pump through the ground condenser to the top of the deaerator for start-up. Condensate characterized in that a conduit, a conduit with a condensate valve from the bottom of the starting deaerator to the upper part of the water storage tank, and an air vent valve communicating with the upper part of the water storage tank are provided. Degassing device.