JPH0861011A - Separated storage method for deaeration and condensation - Google Patents

Abstract

PURPOSE: To enable immediate starting of a steam turbine plant without requiring deaerating operation at the re-starting of the plant even if a condenser is destructed by vacuum while it is stopped. CONSTITUTION: When a steam turbine plant is stopped, a separate deaerator for starting 3 is vacuated by a vacuum pump 6. Also the condensate in a condenser 2 of the steam turbine plant is fed condensedly from the condenser 2 to the deaerator for starting 3 by pressure difference for separated storage. Thus the plant is prepared for re-starting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deaerated condensate isolation method applied to a steam turbine condenser.

[0002]

2. Description of the Related Art The structure of a conventional condenser will be described with reference to FIG. In FIG. 2, reference numeral 1 is a steam turbine, and its condenser 2 is connected to a vacuum pump 6 via a condenser vacuum extraction valve 7. Further, the condenser 2 is connected to the boiler via the condensate pump 4 and the ground condenser 5, and is also connected to the downstream of the ground condenser 5 via the condensate recirculation valve 12.

Further, FIG. 3 shows a conventional system having a deaerator for starting. In FIG. 3, reference numeral 3 denotes a deaerator for starting, which is connected to the condenser 2 via the vent valve 9 and the condenser communication valve 10. Further, the deaerator 3 for startup is connected to the downstream of the ground condenser 5 via the condensate recirculation valve 12 and also to the steam system via the auxiliary steam supply valve 13.

In the conventional steam turbine plant having such a structure, when the condenser 2 is ruptured in vacuum, the deaerated water in the condenser hot well comes into contact with the atmosphere and the amount of dissolved oxygen in the condensate increases. Since the temperature rises significantly, when the plant is restarted, it is necessary to degas the condensate in the condenser hot well again after the vacuum of the condenser 2 has been established. , It took time to start the plant.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a condenser for a conventional steam turbine plant, which eliminates the deaeration operation required when the plant is restarted after a vacuum break and enables quick startup. The task is to do. In addition to this, an object of the present invention is to provide a method for handling deaerated condensate that satisfies the following conditions.

[0006] Degassing operation can be performed quickly even when the plant is cold.

[0007]. Ensure that the minimum condensate flow return to the gland condenser does not return to the condenser during vacuum rise when the plant is restarted (the deaerated water passing through the deaerator is not exposed to the atmosphere).

[0008] The expansion of the condenser hot well will also affect the building (excavation of the earth building), so the condenser hot well should be made as small as possible.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a small deaerator such as a deaerator for activating water in a condenser hot well, or a condenser-integrated starter. A method of sucking up and storing it in the water storage part of the plant using a vacuum pump such as an existing condenser vacuum pump will be adopted.

That is, according to the present invention, when the steam turbine plant is stopped, the small deaerator is evacuated by a vacuum pump to condense the condensate in the condenser of the steam turbine plant from the condenser due to the pressure difference. The method of transfer to a container and storage in isolation is adopted.

[0011]

In the present invention, when the vacuum of the condenser is broken, the vacuum of the small deaerator such as the starting deaerator is held by the above-mentioned method, and the connecting pipes provided between them are used. Due to the pressure difference, the condensate can be moved to the small deaerator side and stored. Therefore, according to the present invention, even if the condenser is vacuum-disrupted when the steam turbine plant is stopped, the steam turbine plant can be quickly started without degassing operation when the plant is restarted.

[0012]

The embodiment of the method according to the present invention is shown in FIG.
It will be specifically described based on. Note that FIG. 1 shows a system diagram of a steam turbine plant for carrying out the isolated storage method of degassed condensate according to the present invention. However, parts having the same configuration as the system in the system diagrams shown in FIGS. 2 and 3. Are denoted by the same reference numerals, and redundant description thereof will be omitted.

In FIG. 1, the top of the starting deaerator 3 is connected to a vacuum pump 6 via a starting deaerator vacuum extraction valve 8. Further, a condenser condensate water withdrawal valve 11 is interposed in the line from the condenser 2 to the condensate pump 4, and the bottom portion of the starting deaerator 3 is connected to the downstream side of the condensate water withdrawal valve 11. . Other configurations in the system diagram shown in FIG. 1 are shown in FIG.
It has the same configuration as the system shown in.

In the system of FIG. 1 thus constructed, the starting deaerator 3 is not used in normal load operation, but is used when a condensed water deaerating operation is required at the time of cold start. Therefore, the valves 8, 12, 13 are closed and the valve 11 is open.

In order to transfer the water in the condenser hot well to the starting deaerator 3 side when the steam turbine plant is stopped, the valves 7, 9 and 10 are closed, the valve 8 is opened, and the vacuum pump 6 is used to deaerate. The vacuum in the container 3 is maintained. From this state, the supply of turbine ground steam is stopped and the condensate pump 4 is stopped. As a result, as the internal pressure of the condenser 2 rises, the condensate in the condenser hot well moves to the starting deaerator 3 side through the condenser pipe and the valve 11. When the water in the condenser hot well is completely transferred to the starting deaerator 3, the valve 11 is closed to store the condensed water.

As described above, the deaerated condensate in the condenser 2 is isolated in the starting deaerator 3 when the steam turbine plant is stopped. Then, when the steam turbine plant is restarted, the deaerator 3 for start-up until the vacuum on the condenser 2 side is established.
Since the startup preparation is done on the side, the plant startup time can be shortened.

[0017]

By adopting the method of the present invention, deaeration and condensate water can be isolated when the steam turbine plant is stopped, and even when the steam turbine plant is restarted, the deaerator and condensate for start-up until the condenser side vacuum is established. Startup preparation (establishing ground steam) can be performed in a cycle composed of pumps.

As a result, it is possible to omit the conventional operation of degassing the hot well water after establishing the vacuum, and the plant start-up time can be shortened. The position of the bottom of the condenser is the same as the conventional one, and the installation level of the condensate pump is also the same as the conventional one, so there is little impact on the building side.

[Brief description of drawings]

FIG. 1 is a system diagram of a steam turbine plant for carrying out a method for isolating and storing degassed condensate according to the present invention.

FIG. 2 is a system diagram showing a conventional degassing system for condensing water in a steam turbine plant.

FIG. 3 is a system diagram showing a condensate treatment system including a conventional deaerator for startup.

[Explanation of symbols]

 1 Steam Turbine 2 Condenser 3 Start Deaerator 4 Condensate Pump 5 Ground Capacitor 6 Vacuum Pump 7 Condenser Vacuum Extraction Valve 8 Start Deaerator Vacuum Extraction Valve 9 Vent Valve 10 Condenser Communication Valve 11 Recovery Water condensate drain valve 12 Condensate recirculation valve 13 Auxiliary steam supply valve

Claims (1)

[Claims] 1. When the steam turbine plant is stopped, the compact deaerator is evacuated by a vacuum pump to condense water in the condenser of the steam turbine plant from the condenser to the compact deaerator due to a pressure difference. An isolated storage method for degassed condensate, which is characterized in that it is transferred and stored in isolation.