JPS588992A - Sidestream condensation system - Google Patents

Abstract

PURPOSE:To rationalize arrangement and pipings of means in the sidestream condensation system by a method wherein condensating and desalting bypass lines provided at a plurality of condensating and desalting devices are normally opened partially, closed when a seawater leakag occurs in the condenser so as to flow condensate to the condensing and desalting devices. CONSTITUTION:In the normal operation, a predetermined amount of condensate from a condensating and filtering device 6 is sent to some of the plurality of condensing and desalting devices 17 to undergo a water quality treatment therein, whereas th rest flows through a bypass valve 18. The condensate, both from the device 17 and through a valve 18, joints at the outlet of the condensing and desalting device 17. If a salt detector 19 detects a seawater leakage in a coolant pipe group in the condenser 1, the detector 19 provides an output representing the amount of leakage to a discriminator 20, which closes rapidly the bypass valve 18 of the condensing and desalting device 17 as soon as the leakage reaches a permissible limit value. Under this control, the whole amount of the condensate fow through all of the condensing and desalting devices 17, thereby preventing any entrance of chlorine ions into the nuclear reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sidestream condensate system.

The configuration of a conventional IJ-mu condensate system will be explained with reference to FIG.

Steam turbine exhaust steam and feed water heater drain are condensed in the condenser 1 and enter the first hot well 2 as condensate.

The condensate in the first hot well 2 is pressurized by a condensate purification circulation pump 3 and sent to a condensate purification device having a condensate E-filtration device 6 and a condensate desalination device 7, where it is treated for water quality (impurity treatment). After that, a gland steam condenser 8 condenses the sealed steam in the gland section of the turbine and valves, and air condenses the exhaust steam of the steam ejector used to extract non-condensable gas in the condenser 1. It is sent to the extractor 9.

The condensate whose temperature has increased due to heat exchange in the grand steam condenser 8 and the air extractor 9 returns to the condenser second real well 14 from the suction header 13 of the condensate pump via the water level control valve 12 .

Of the condensate that enters the condensate pump suction header 13 via the water level control valve 12 of the side stream tank 11,
Condensate pump 1 adjusts the required flow rate according to the power plant operating load.
5, the water is sent to the main system 16. The remaining surplus water overflows from the upper part of the second real well 14 and
Return to Honto Well 2.

The intermediate storage tank 11 is installed for the purpose of applying pressure to the side stream condensate system using a static head to prevent water column separation and recombination, and the water level is kept constant by a water level control valve 12.

In such a side stream condensate system, the most important elements in the layout plan and piping plan are the condensate filtration device 6 and the condensate desalination device 17. This means that each device is divided into about 10 series, and each series has an inlet/outlet valve, a flow rate detection device, a flow rate control valve, a condensate filtration tower, or
This is because there is a condensate desalination tower and each branch pipe, which is the largest in the height and horizontal directions, and also constitutes a complicated pipe route. In this way, the large number of series of condensate purification equipment, that is, the number of towers, becomes a factor that precludes rational layout planning and piping planning.

An object of the present invention is to provide a side stream condensate system in which the arrangement plan of each device and the piping plan are rationalized.

A feature of the present invention is that the condensate desalination equipment bypass lines installed in a plurality of condensate desalination equipment are operated with some of them open during proper operation, and seawater leakage from the condensers occurs. In the side stream condensate system, the condensate is detected by a salt detection device, the bypass line is closed, and the condensate is passed through all the condensate desalination devices to purify the condensate.

A side stream condensate system that is an embodiment of the present invention @
Shown in Figure 2.

In the figure, steam turbine exhaust steam and feed water heater drain are condensed in a condenser 1 and enter a first real well 2 as condensate. The condensate in the first real well 2 is pressurized by the condensate purification circulation pump 3 and subjected to water quality treatment by the condensate filtration device 6. A certain required flow rate of the condensate that has exited the condensate filtration device 6 is passed through a part of the condensate desalination device 17 for water quality treatment, and the remaining flow passes through the bypass valve 18 and is then transferred to the condensate desalination device 1.
Merge at exit 7. The combined condensate undergoes heat exchange in the grand steam condenser 8 and the gust extractor 9, and then passes through the water level control valve 12.
The required amount is sent to the main system 16 by the condensate pump 15 according to the operating load of the power plant, and the excess condensate enters the condenser second real well 14. , overflows and the first condenser
Return to Honto Well 2.

Of the condensate filtration device 6 and condensate desalination device 17, which have condensate water quality treatment functions, the condensate filtration device 6 mainly removes crud in condensate, and the condensate desalination device 17 mainly removes chlorine. Its function is to remove ions.

During normal operation, the system configuration shown in Figure 1 is sufficient to ensure the quality of the water supply at the reactor inlet. Desalination equipment 1
Even if there is condensate that bypasses the condensate filter 7, most of the crud is removed by the condensate filtration device 6. In the condensate desalination device 17, when seawater leaks from the cooling pipes of the condenser 1, chlorine ions are carried into the reactor and cause stress corrosion cracking of reactor components and piping made of stainless steel. It is installed for the purpose of removing chlorine ions to prevent this.

Here, the salt detection device 19 detects seawater leakage from the cooling pipe nest in the condenser 1, and determines the amount of seawater leakage using the determination device 20.
Output to. The determiner 20 suddenly closes the bypass valve 18 of the condensate desalination device 17 when the amount of seawater leakage reaches an allowable limit value. With this control, all condensate passes through all the condensate desalination devices 17, and chlorine ions are not brought into the reactor.

In this case, the condensate flow rate of the sidestream condensate system decreases, which appears as a drop in the level of the condenser second real well 14, but at this time, stable operation can be achieved by reducing the reactor load. Continued.

Here, just by reducing the number of condensate demineralization columns, it is possible to reduce equipment by approximately 700 million yen.

According to the present invention, there are the following effects.

It is now possible to reduce the number of condensate desalination equipment towers, improving building space and maintenance/inspection space, and streamlining the piping planning around the condensate desalination equipment, which was previously considered to be extremely complicated. become a target.

[Brief explanation of the drawing]

FIG. 1 is a conventional side stream condensate system diagram, and FIG. 2 is a side stream condensate system diagram according to an embodiment of the present invention.

Claims (1)

[Claims] 1. The first well of the condenser that stores condensed water from the exhaust steam of the steam turbine and sends the condensate to the condensate purification system, and the first well of the condenser that stores condensate from the condensate purification system. In a side stream condensate system comprising two main wells and a main system branching from a system that leads condensate from the condensate purification system to the second real well and supplying the amount of condensate required by the power generation plant, the condensate A bypass valve is installed in a plurality of condensate desalination devices provided in the purification system, a condensate salt test device is installed near the first real well, and the bypass valve is installed in accordance with the detection signal of the salt test device. A side stream condensate system characterized by installing a control device that operates the opening and closing of the side stream condensate system.