JPS60120294A - Nuclear power plant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a nuclear power plant, particularly a boiling water plant equipped with a turbine bypass system that bypasses a turbine and releases steam generated in a nuclear reactor to a main condenser. Regarding nuclear power plants.

[Technical background of the invention and its problems] Conventionally, in boiling water nuclear power plants, the turbine is stopped during plant startup or shutdown operation.

When a nuclear reactor is in operation, it is necessary to release the steam generated within the reactor.Also, if surplus steam is generated due to sudden load during normal plant operation, the turbine bypass valve is opened and the condenser is removed. It is necessary to release excess steam to the tank.

FIG. 1 is a schematic diagram of a boiling water nuclear power plant equipped with a conventional turbine bypass device.

In the figure, the steam generated in the reactor 1 is transferred to the main steam pipe 1.
4 through the king steam stop valve 21. The steam is guided to the turbine 2 through the steam control valve 22, and after doing work by rotating the rotary machine 3, the turbine 2 is led to the condenser 4.The ascites from the condenser 4 is then sent to the low pressure condensate pump 5. The water is guided to the condensate purification device 6 at is heated and returned to the reactor 1. Also, from the turbine 2, both feed water heaters 8. Bleed check valve 23.23 and bleed pipe 15 to lO
．． 15 are connected.

On the other hand, a turbine binosu valve 24 is installed in the middle of the main steam pipe 14.
, a turbine bypass device is provided which leads to the condenser 4 via a bypass steam pipe 16. This turbine bypass device is used to release the steam generated in the reactor to the condenser 4 because the reactor 1 is in operation while the turbine 2 is stopped during startup or shutdown of the plant, or when the load suddenly decreases. The tM water container 4 is provided to release excess steam generated by the tM water container 4. The steam led to the condenser 4 is cooled by the cooling water 30E and becomes condensate, but all the heat at this time is discarded through the cooling water 30, resulting in heat loss. There were 0 defects. [Objective of the Invention] The present invention was made in order to eliminate the above-mentioned defects. The purpose of the present invention is to provide a nuclear power generation plant designed to achieve this goal.

[Summary of the Invention] In order to achieve the above object, the present invention provides a piping system for transporting steam generated in a nuclear reactor from a main steam pipe to a main turbine, through a watertight and feed water heater, and back to the reactor. In a nuclear power plant provided with a turbine pass steam pipe that branches from a steam pipe, passes through the main turbine, and is connected to the condenser, the main steam pipe of the turbine bypass steam pipe is provided. A branch pipe is further provided on the downstream side of the branch point, and an accumulator is provided in this branch pipe, and the steam generated in the accumulator is sent to the feed water heater or the condenser.

Makeup water to the accumulator is supplied from a condensate storage tank, and a turbine gland seal steam generator can also be disposed in the piping from the accumulator to the feed water heater.

[Embodiments of the invention] An embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows a schematic diagram of one embodiment of the present invention.
The same parts as those in the figures will be described with the same reference numerals. As shown in the figure, the steam generated from the reactor 1 is transferred to the main steam pipe 14.
Turn on the main steam stop valve 21 and the steam control valve 22.Turbine 2
The turbine 2 rotates the rotating machine 3 and other parts to perform work, and then the water is guided to the condenser 4. Then, condensate is drained from the condenser 4, and a condensate purification device 6 is used with the low pressure condensate pump 5.
The high pressure condensate pump 7 further supplies the water to the feed water heater 8.
After being guided and heated, the reactor feed water pump 9 guides it to the high pressure feed water heater lO, where it is heated and returned to the reactor 1. Further, a pipe branched from the main steam pipe 14, passed through the turbine bypass valve 24, and branched from the middle of the bypass steam pipe 16 is connected to a bypass steam stop valve 25.
and is connected to an accumulator 11 provided downstream. The steam generated in the accumulator 11 is transferred to the heating steam pipe 1
7 is connected to the bleed pipe 15 which is connected from the turbine 2 to the feedwater heater 8 via the heated steam check valve 27 . Also,
Pipes branched from upstream of the bypass steam stop valve 25 provided in the bypass steam pipe 16 are connected to the turbine 2 on one side and to the condenser 4 on the other side via the bypass steam relief valve 26 . Furthermore, a relief steam pipe 18 is installed which branches off from the heating steam pipe 17 and connects to the condenser 4 via a relief steam stop valve. In order to keep the water level in the accumulator 11 constant, makeup water is fed from the condensate storage tank 12 by the makeup water pump 13.

Next, we will explain the operation of this embodiment.0 Now, when the plant is started up, steam is generated in the reactor 1, and the turbine 2 is not started, the reactor steam is transferred to the turbine bypass valve 24. is open and flows into the bypass steam pipe 16. Additionally, when the load on the turbine 2 suddenly decreases during plant operation, the steam control valve 22 closes by that amount to limit the amount of steam flowing into the turbine 2, but the reactor cannot follow this, so excess steam The turbine bypass valve 24 opens and the steam flows into the bypass steam pipe 16.

In such a case, if the bypass steam relief valve 26 is closed and the bypass steam stop valve 25 is opened, the steam will flow into the accumulator 11 and heat the water in it, increasing the water temperature and internal pressure. . A heating steam pipe 17 is connected to the accumulator 1.
7 is connected to the bleed pipe 5, and a heated steam check valve 27 is provided in the middle so that it opens at a certain pressure or higher.

When the pressure in the accumulator Il increases above that pressure, the steam in the accumulator 11 is transferred to the heating steam pipe 17.
, the heated steam flows through the check valve 27 and the bleed pipe 15 to the feed water heater 8 and is used as heating steam.

If the opening pressure setting value of the heating steam stop valve 27 is set slightly higher than the steam pressure in the bleed pipe 15, the accumulator 1
Due to the inflow of steam from 1, the bleed restriction from turbine 2 is commensurately reduced. As a result, the amount of steam in the turbine 2 increases and the output of the turbine increases, but since the output of the turbine 2 is suppressed by the load of the generator 3, there is a surplus of steam and the turbine control device is activated. When the steam control valve 22 is throttled down by the required amount, steam will be left over by that amount on the reactor 1 side, so the output control device of the reactor will operate to reduce the thermal output and reduce the amount of steam generated.

Further, the heating steam pipe 17 is provided with a branch, and the steam is connected to the condenser 4 through the steam release pipe 18 via the steam release stop valve 28. This is to open the relief steam stop valve 28 and release steam to the condenser 4 when the pressure inside the accumulator 11 increases while the feed water heater 8 is stopped for maintenance etc. In addition, the bypass steam pipe 16 has a bypass steam relief valve 2.
6 is provided and is normally closed, but if the accumulator 11 is out of operation for maintenance or the like, it is left open to allow bypass steam to escape directly to the condenser 4.

FIG. 3 is a schematic diagram of another embodiment of the present invention, and the same parts as in FIG. 2 are given the same reference numerals, and detailed explanation thereof will be omitted.

The difference between this embodiment and the embodiment shown in FIG. This is the configuration. That is, as shown in FIG.
It branches from the upstream side of the relief steam stop valve 28 of the heating steam pipe 17 provided in The seal steam generation candy 20 is configured to be connected to the feed water heater 8.The main steam pipe 141r1!) is distributed upstream from the bypass steam pipe 16 branched from the main steam pipe 14, and the turbine clamp seal steam generation The piping is connected to the turbine gland seal steam generator 20 through the control valve 3I, and this piping system is designed to send a certain amount of cavity air from the main steam pipe 14 to the two-bing gland seal steam generator 30. belongs to.

As explained above, according to each of the above embodiments (2), while the steam generated by the accumulator is used, the amount of steam generated in the reactor can be reduced, so the life of the reactor fuel can be extended by that much. In addition, unless the amount of steam generated by the reactor is suppressed, the turbine bleed air negative will be reduced, so the turbine output will increase, making it possible to meet the temporary demand for increased output.

[Effects of the Invention] According to the present invention, the life of the reactor fuel can be extended by IA, the water supply system can be started up quickly, and the thermal shock of the condenser due to release to bypass steam can also be reduced. It is possible to provide a nuclear power plant having such excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a boiling water nuclear power generating plant equipped with a conventional exhaust system in a turbine 2, Fig. 2 is a schematic diagram of an embodiment of the present invention, and Fig. 3 is a schematic diagram of another embodiment of the present invention. FIG. 2 is a schematic diagram of an example. ■... Nuclear reactor 2... Turbine 4... Condenser 5, 7, 9.13... Pump 6...
・Condensate purification system @ 8, 10... Feed water heater l]...
Accumulator 12... Condensate storage tank 14...
Main steam pipe 16...Bypass steam pipe 17...Heating steam pipe 20...Turbine grand seal steam generator 21...
・Main steam stop valve 22...Steam control valve 24...Bypass valve 25...Bypass steam stop valve 2ti...Bypass steam relief valve 27.29...Heating steam check valve 31...Adjustment Patent attorney Yoshiaki Inomata (1 person #1) 1st
Figure 2

Claims (1)

[Scope of Claims] (1) A piping system in which the steam generated in the nuclear reactor is returned from the main steam pipe through the main turbine, the condenser, and the feedwater heater to the reactor again, and the live steam pipe branches off the In a nuclear power plant that is provided with a turbine bypass steam pipe that bypasses the main turbine and is connected to the condenser, the turbine bypass steam pipe is downstream of a branch point of the main steam pipe (a second branch pipe is provided). , an accumulator is provided in the branch pipe, and the steam generated in the accumulator is transferred to the
A nuclear power plant characterized in that the water is sent to a feed water heater or the condenser. (2) Nuclear power plant 1 according to claim 1, wherein make-up water to the accumulator is supplied from a condensate storage tank.
m plant. (8) A nuclear power plant according to claim WJ1, wherein a turbine gland seal steam generator is disposed in a pipe leading from an accumulator to a feed water heater.