JPS5915897A - Auxiliary boiler device for reactor 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 is directed to auxiliary nuclear reactor plants equipped with a plurality of auxiliary boilers. Regarding Ira equipment.

[Technical background of the invention]

For example, a boiling water reactor plant is equipped with an auxiliary boiler equipped with multiple auxiliary boilers that use fuel such as heavy oil. For example, they are used for heating inside nuclear reactor buildings, hot water supply for laundry facilities and shower facilities for employees, and as a heat source for waste treatment systems.

On the other hand, the turbine gland section of the generator-driving turbine in the nuclear reactor plant performs a shaft sealing function by supplying a portion of the main steam that is frequently generated from the reactor pressure vessel to the gland steam generator and start/stop estimator. However, it is configured to prevent leakage of main steam from the turbine gland.

However, during scram operation or reactor shutdown, the amount of main steam supplied decreases, so unless a separate steam supply source is provided to operate the gland seal system in the turbine gland, the shaft sealing function in the turbine gland will fail. This will cause radioactive main steam to leak out. Therefore, during scram operation or reactor shutdown, a large amount of steam generated by the auxiliary boiler equipment is also supplied to the turbine gland.
Constructed to prevent leakage of main steam.

Incidentally, the amount of steam demanded by auxiliary equipment within a nuclear reactor plant fluctuates greatly throughout the year. Therefore, the required number of auxiliary boilers is operated according to the required amount of steam. For example, in the summer, there is no need to heat the building, and a small amount is required as a heat source for the waste treatment system, so the amount required is smaller than in the winter. Therefore, in the summer, for example, two auxiliary units, one large and one small, operate only the smaller capacity boiler.
Large-capacity boilers should be stopped.

[Problems with background technology]

When the amount of main steam generated from the reactor pressure vessel decreases, the steam generated from the boiler of the auxiliary boiler equipment is supplied to the turbine gland to prevent leakage of radioactive main steam. If the main steam supplied from the reactor pressure vessel to the turbine gland decreases when most of the steam supplied from the reactor pressure vessel is used by auxiliary equipment, the shaft sealing function in the turbine gland will be impaired. It turns out. In such cases, in the summer when only some of the auxiliaries are used, it may be possible to supply steam to the turbine gland by operating the remaining boilers, but it is possible to supply steam to the turbine gland. In the winter when the boiler is in use, the turbine gland cannot meet the required amount.

Therefore, in order to reliably prevent leakage of the main steam in any case, the capacity of the auxiliary ylr is made to have a sufficient capacity. Therefore, there were problems in that the capacity of each auxiliary boiler had to be unnecessarily increased, and the number of auxiliary boilers had to be increased unnecessarily. In addition, due to the increase in the capacity and number of such boilers, equipment costs and operating costs are high, and the area occupied by the P1 auxiliary boiler has to be unnecessarily large.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The purpose is to ensure the safety of the nuclear reactor plant without unnecessarily increasing the capacity or number of auxiliary boilers.
It is an object of the present invention to provide an auxiliary boiler device for a nuclear reactor plant, which can thereby reduce equipment costs and operating costs, and can also reduce the area occupied by the auxiliary boiler.

[Summary of the invention]

The auxiliary boiler device for a nuclear reactor plant according to the present invention includes a plurality of auxiliary boilers, a load steam supply pipe that supplies steam generated from these boilers to auxiliary equipment in the nuclear reactor plant, and a reactor pressure vessel. A gland sealing steam supply pipe that supplies steam generated in large amounts from the auxiliary boiler to the turbine gland section, which is supplied with main steam and fully exhibits the shaft sealing function of the generator-driving turbine, and a gland sealing steam supply pipe. a first valve inserted in the pipe and held in a closed state during rated reactor operation; and a first valve inserted in the load steam supply pipe and held in an open state during rated reactor operation. The second valve and the second valve operate the necessary number of the plurality of auxiliary boilers according to the required amount of steam in the auxiliary equipment, and the first The present invention is characterized by comprising a control circuit that opens the second valve and closes the second valve at the same time. Therefore, when the amount of main steam supplied to the reactor pressure vessel decreases, the steam supplied from the auxiliary reactor is preferentially supplied to the turbine gland, and the turbine gland The shaft sealing function of the part will be maintained.

[Embodiments of the invention]

The drawings show one embodiment of the present invention, in which numeral 1 indicates a reactor pressure vessel of a boiling water nuclear reactor plant, and numeral 2 in the figure indicates a reactor core within this pressure vessel 1. Furthermore, a coolant (soft water) 4 is housed inside the pressure vessel 1 . On the other hand, 6 in the figure is a generator, and 8 in the figure is a turbine for driving this generator 6.

A condenser 10 is provided below the turbine 8.

Therefore, due to the reaction heat of the nuclear fuel in the reactor core 2, the υ coolant 4
is heated and boiled to become main steam, which is supplied to the turbine 8 through the entire main steam pipe 12. and turbine 8
The main steam that drove the reactor is cooled and liquefied in the condenser 10 and returned to the reactor pressure vessel 1 through the water supply piping 16 by the water supply bong 7''14.

A portion of the main steam is also supplied to the turbine gland section 20 of the turbine 8 through a seal pipe 18 branched from the main steam pipe 12 . As a result, the turbine gland section 20 exhibits a shaft sealing function and prevents leakage of main steam.

On the other hand, 22 in the figure is an auxiliary device, and this auxiliary device? The boiler device 22 is provided with two auxiliary boilers, one large and one small, namely a main boiler 24 and a sub-boiler 24B. And each boiler 24A.

24B is provided with heavy oil burners 261', 26B. In addition, 28 in the figure is a heavy oil tank, and this heavy oil tank 2
A flow control valve 30 is attached to the outlet 8. The flow control valve 30 and each of the heavy oil burners 26 are provided with a 26B
The fuel pipes 32A and 32B are connected to each other by multiple fuel pipes 32A and 32B.

A fuel pump 34 is inserted into the fuel pump 32B.

Further, numeral 36 in the figure is a water supply tank, and a flow rate control valve 38 is attached to the outlet of this water supply tank 36. A water supply pipe 4θA is connected between this flow rate control valve 38 and each of the heavy oil burners 26 and 26B.

40B, each water supply pipe 40A, 40B
Inside, there is a water supply pump 42, 42B, a flow rate detector 44,
44B and 46B are connected to the flow control valve 46, respectively.

Also, 48 in the figure is a steam supply header, and this header 48
are connected to each of the boilers 24 and 24B via steam pipes 50A and 50Bt.

A boiler outlet valve 52 is provided in each steam pipe 50A, 50B.
k, 52B and header population valve 54A.

54B are inserted respectively. Further, a gland sealing steam supply pipe 56 and a load steam supply pipe 58 are connected to the steam supply header 48 . The steam supply pipe 56 for gland sealing is connected to the turbine gland portion 2 of the turbine 8.
0, the supply pipe 56 contains the first
A valve 60 is inserted. Also, the load steam supply pipe 58
A second valve 62 is inserted therein at the outlet of the header 48. The load steam supply pipe 58 is branched into a plurality of pipes (for example, three pipes) on the downstream side of this second valve 62, and each of the branched load steam branch pipes 58
In 58B, 58C, the control valve 64, 64B, 64
C is inserted respectively. And said Daira 24A
.

The steam generated from 24B passes through the second valve 62 and is supplied to load steam branch pipes 581.58B and 58C, and is used for various purposes in auxiliary equipment 66 in the reactor plant, such as for heating inside the reactor building, It is configured to be used for hot water supply in laundry facilities and shower facilities for employees, and as a heat source for waste treatment systems.

The figure shows a 68Vi control circuit. A demand increase signal 70 is input to this control circuit 68 when the required amount of steam in the auxiliary equipment 66 increases. 1
8f: A main steam reduction signal 72 is input as the main steam supplied to the turbine gland section 20 decreases through the main steam.

-10= For example, when the required amount of steam in the auxiliary equipment 66 is small, such as in the summer, the demand amount increase signal 70 is not input to the control circuit 68, and in such a case, the control circuit 68d
Heavy oil pump f34B and heavy oil burner 2 with sub-in 24B side
Is it possible to output the drive signal 74Bf only to 6B and use it as a small capacity sub? Only the boiler 24B is operated, but when the demand increase signal 70 is input, such as in winter when the required amount of steam is large, the heavy oil pump 94A and the heavy oil burner 26A on the main boiler 24A side are also operated. Signal 74Ai output, both main and sub r
Wira 24A.

24Bf will be operated at the same time. Note that the demand increase signal 70 may be generated manually, but it is preferable that the demand increase signal 70 be generated automatically when a large number of operations related to steam use are simultaneously performed in the auxiliary equipment 66. . Also, during reactor rated operation, the first valve 6
0 is held in the closed state, and the second valve 62 is held in the open state. However, when the main steam reduction signal 72 is input to the control circuit 68, the control circuit 68Fi causes the first valve 60 to open. At the same time as outputting a signal 76 to open this valve 60,
A valve closing signal 78 is output to the second valve 62 to close this valve 62.

In the auxiliary boiler device 2 with the above configuration, when the amount of main steam supplied from the reactor pressure vessel 1 to the turbine gland section 20 of the turbine 8 decreases, the output from the control circuit 68 is used to control the When the first valve 60 is opened and the second valve 62 is closed, the steam generated in the main and sub-side digi 24 in a quantity as large as 24B flows through the gland sealing steam supply pipe 56 to the turbine gland of the turbine 8. It is preferentially supplied to the section 20. Therefore, the shaft sealing function in the turbine gland section 20 is maintained, and leakage of radioactive main steam is reliably prevented.

In addition, at this time, the supply of steam to the auxiliary equipment 66 will be temporarily stopped, but since it is not equipment to ensure safety in the nuclear reactor plant, it may cause a hindrance in ensuring the safety of the plant. does not occur. And the main and vice Deira 24A.

24Bf Since plant safety can be ensured without unnecessarily increasing capacity or increasing the number of auxiliary equipment, equipment costs and operating costs can be reduced. It is also possible to reduce the area occupied by the irra.

〔Effect of the invention〕

As described above in detail based on the embodiments, the auxiliary boiler device for a nuclear reactor plant according to the present invention has multiple auxiliary boilers. the load steam supply pipe that supplies the steam generated from these digi to auxiliary equipment in the reactor plant, and the shaft sealing function in the generator-driving turbine that is supplied with main steam from the reactor pressure vessel. A gland sealing steam supply pipe that supplies the steam generated by the auxiliary boiler to the turbine gland that exerts the a second valve inserted into the load steam supply pipe and kept open during rated reactor operation; Part 13 - Operate the necessary number of auxiliary diggers out of the several auxiliary diggers, and at the time of reactor startup, power reduction, and reactor shutdown, fully open the first valve and at the same time open the second valve. This system is characterized by being equipped with a control circuit that closes the valve, thereby ensuring the complete safety of the nuclear reactor plant without unnecessarily increasing the capacity or number of auxiliary boilers. It is possible to obtain significant effects such as reducing operating costs and reducing the area occupied by the auxiliary boiler.

[Brief explanation of the drawing]

The drawing is a schematic diagram of an auxiliary boiler device showing an embodiment of the present invention. 1... Reactor pressure vessel, 6... Generator, 8... Turbine, 12... Main steam piping, 18... Seal piping, 20... Turbine gland section, Hitoshi... Auxiliary Boiler equipment, 24A...Main boiler (auxiliary boiler), 24B
...Vice? Ira (auxiliary? Ira), 56... Steam supply pipe for gland seal, 58... Steam supply pipe for load, 60
... first valve, 62 ... second valve, 14-66 ... auxiliary equipment in the plant, 68 ... control circuit, 70 ... demand increase signal, 72 ... main Steam reduction signal, 74, 74B... drive signal, 76... valve opening signal, 78... valve closing signal. Applicant's agent Patent attorney Takehiko Suzue 15-521-

Claims (2)

[Claims] (1) Multiple auxiliary boilers, a load steam supply pipe that supplies steam generated from these boilers to auxiliary equipment in the reactor plant, and a generator that is supplied with main steam from the reactor pressure vessel. A gland sealing steam supply pipe that supplies steam generated from the auxiliary to the turbine gland that performs the shaft sealing function in the drive turbine, and a gland sealing steam supply pipe that is inserted into this gland sealing steam supply pipe to maintain the reactor's rated operation. The interior includes a first valve held in a closed state, a second valve inserted in the load steam supply pipe and held in an open state during rated reactor operation, and a second valve in the auxiliary equipment. According to the required amount of steam, the plurality of auxiliary units operate the necessary number of the auxiliary units, and simultaneously open the first valve at the time of reactor startup, output reduction, and reactor shutdown. Second
An auxiliary device for a nuclear reactor plant characterized by being equipped with a control circuit for closing a valve? Ira device. (2) The control circuit fully opens the first valve and fully closes the first valve by inputting a scram signal frequently generated by the reactor protection system or a pressure drop signal in the reactor pressure vessel. An auxiliary boiler device for a nuclear reactor plant according to claim (1), characterized in that it is configured as follows.