JPS6293698A - Turbine exhaust-gas treater - 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 particularly relates to a turbine exhaust gas treatment device in a nuclear power plant.

[Technical Background of the Invention and Problems thereof] In atomic couplants, radioactive emissions are reduced by adopting an activated carbon exhaust gas system, etc. in order to reduce radioactive emissions. In conventional nuclear couplers, during normal operation, an air extractor that uses reactor steam as the working steam source is operated, and exhaust gas is activated (passed through the primary exhaust gas system and released from the stack. , the reactor steam pressure is reduced to a pressure that can drive the air extractor (e.g. 14 km
2g>, the steam from the station boiler (for example 7.
Exhaust gas is continuously processed by switching to a start/stop air extractor whose operating source is 8k (J/Cm2 (]).

Working steam is used by reducing the pressure of the reactor steam pressure 70k (1/cm2 g) to saturated steam of 14k (]/cm2 g using a pressure reducing valve. However, even if the steam pressure in the reactor drops during shutdown, equipment Since the humidity level is delayed due to the retained heat of the piping, the working steam has a temperature of 14K (1/cm2)
g of superheated steam may be supplied. At this time, the temperature of the turbine exhaust gas treatment device would rise, affecting subsequent equipment, and there was a risk that continuous treatment of exhaust gas would not be possible.

(Object of the Invention) An object of the present invention is to provide a turbine exhaust gas treatment device that can reduce radioactivity and continuously release exhaust gas even when the plant is stopped.

[Summary of the Invention] A turbine exhaust gas treatment device according to the present invention includes an air extractor that extracts exhaust gas from a condenser using main steam, an activated carbon exhaust gas treatment system connected to the air extractor, and the air extractor. and a starting/stopping ejector driven by the in-house boiler steam installed in parallel with the plant. Alternatively, it is characterized in that it is configured to operate when the main steam becomes superheated steam and rises above the saturated steam temperature.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. A reactor pressure vessel 1 is connected to a turbine 3 by a main steam pipe 2. The main steam pipe 2 is provided with a main steam isolation valve 4, and the inlet of the turbine 3 is provided with a main steam stop valve 5.

During normal operation of the turbine 3, the reactor pressure vessel 1
Main steam is sent to the turbine 3 via the main steam isolation valve 4 and the main steam stop valve 5, and then condensed in the condenser 6. Furthermore, a turbine bypass pipe 8 having a turbine bypass valve 7 is provided between the main steam pipe 2 and the condenser 6 on the upstream side of the main steam stop valve 5 . Note that these devices are exactly the same as those in conventional nuclear turbine plants.

On the other hand, an air extractor 9 is connected to the condenser 6. A plurality of rows of an exhaust gas preheater 10, an exhaust gas recombiner 11, and an exhaust gas condenser 12 are connected to the air extractor 9, and an activated carbon exhaust gas system 13 and an exhaust gas vacuum pump 14 are connected in this order. It is connected to cylinder 15.

The air extractor 9 has a first stage ejector 16 and a second stage ejector 17, each operated by main steam, and an intercondenser 18 between both epictors 16 and 17.
is connected. Electrically operated valves 19, 20, and 21 are provided upstream of the rough construction unit 16 and upstream and downstream of the second stage ejector 17, respectively. Said painter U
Vise gauges 23, 24 and thermometers 25, 26 are provided downstream of the duct 16, 17, the driving steam supply main steam line 22, and the second stage ejector 17, respectively.

Therefore, in the present invention, the first stage ejector 27 for starting and stopping is operated by the steam of the station boiler in parallel with the electric valve 19 and the first stage ejector 16 in the air extractor 9.
is being charred. Roughly in parallel with the electric valves 20, 21 and the second stage ejector 17, a second stage ejector 28 for starting and stopping is provided which is operated by steam from the local boiler. Note that 29, 30, and 31 are electric valves.

In addition, the steam line 22 of the main steam isolation valve lid 16.17
Similarly, an in-house boiler steam line 32 is provided that supplies driving steam to the start/stop ejectors 27, 28. 2 for inlet and start/stop of this in-house boiler steam line 32
At the exit of the stage ejector 28, pressure gauges 33 and 346 and thermometers 3 and 36 are provided, respectively.

Next, the operation of the turbine exhaust gas treatment device according to the present invention will be explained. When the plant is shut down, preparations for the plant shutdown are first made in the same way as before.

When the reactor pressure starts to drop, the pressure gauge 23 and thermometer 25 of the ejector drive main steam line 22 of the air extractor 9
and the outlet pressure gauge 24 and hygrometer 2 of the second stage ejector 17.
Ejectors 16 and 17 will continue to operate without monitoring 6 and 6.

The main steam pressure is the pressure at which the air extractor 9 can be driven (e.g. 1
4kMcm" (J) or less, both epictors 16 and 17 of the air extractor 9 are stopped, and the electric valve 19.
20.211] L; Electric valve 29.30 after Ko (1)
Open the
Both start/stop ejectors 27 and 28 are started using Cm2 g of saturated steam as the operating source. At this time, the operation is switched to manual or automatic.

In addition, although the main steam pressure ensures a pressure (for example, 14 kg/cm2g>) that allows the air extractor 9 to be driven, the steam temperature increases and the saturated steam (for example, 14 kg/cm2g)
Even if the temperature exceeds 198°C (198°C) at g, stop the air extractor 9's painter 16.17, close the electric valve 19, 20, 21, and close the electric valve 2.
9.30.31 Open both ejectors for starting and stopping 27゜2
8 to start manually or automatically.

There, the reactor pressure decreased roughly to 2.5k (1/C
The turbine bypass valve 7 is closed when the temperature reaches approximately m2 (l).The reactor water is cooled sequentially by a residual heat removal system (not shown).
Do J. Subsequently, the main steam isolation valve 4 is closed to isolate the reactor side and the turbine side, and the air in the condenser is continuously passed through the activated carbon exhaust gas system 13 in a high vacuum state to be purified and then released.

[Effects of the Invention] As described above, in the present invention, a starting/stopping lifter driven by in-house boiler steam is provided in parallel with the air extractor,
The start/stop epi-lidder is configured to operate when the main steam pressure falls below the pressure that is possible to operate the air extractor during plant shutdown, or when the main steam becomes superheated steam and rises above the saturated steam temperature. Therefore, when the plant is stopped, the plant can be stopped safely and in a well-procedure manner without stopping air extraction from the condenser.

[Brief explanation of drawings]

The drawing is a system diagram showing an embodiment of the turbine exhaust gas treatment device according to the present invention. 1... I Kyoko reactor pressure J vessel 2... Main steam pipe 3... Turbine, 6... Condenser 9...
Air extractor, 10... Exhaust gas preheater 13...
・Activated carbon exhaust gas system 15...Exhaust pipe 16...1st stage esector 17...2nd stage shrimp 18...Intercondenser 22...Main steam line for driving ejector 27, 28...
・Epi-lid for starting and stopping 32... In-house steam line representative Patent attorney Noriyuki Chika Yudo Hirofumi Mitsumata

Claims (1)

[Claims] Driven by an air extractor that extracts exhaust gas from the condenser using main steam, an activated carbon exhaust gas treatment system connected to this air extractor, and steam from an in-house boiler installed in parallel with the air extractor. The start/stop ejector is activated when the main steam pressure falls below the pressure at which the air extractor can operate, or when the main steam becomes superheated steam and the temperature rises below the saturated steam temperature. A turbine exhaust gas treatment device characterized in that it is configured to operate when the turbine rises.