JPS587596A - Method of controlling steam generation 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 The present invention relates to a +ff1J control method for a steam generation plant, and particularly relates to a control method for a pumped steam generation plant in which the water level in the second real well of a side stream condenser is lowered. It is.

Water level control in side stream condensers installed in boiling water reactors etc. includes the water level control system for the first and second hot wells (Japanese Patent Application No. 54-39805) and the overflow level control system for the second hot well. Method←Machigan 54-1055
13) etc. In the water level control method for these real wells, one of the two pumps (in operation) of the side stream system (system that raises the temperature of the condensed water accumulated in the first hot well of the ascites device and then guides it to the second hot well) If the flow rate of 74 water (hereinafter referred to as water supply) in the side stream system becomes less than the required flow rate for the sieve water reactor at the gas generator, due to a trip or a malfunction in the side stream system, There was a drawback that the water level in the g2 hontwell decreased, leading to plant shutdown due to loss of water supply.

The object of the present invention is to overcome the drawbacks of the above-mentioned techniques and to provide a method for controlling a steam generation plant that increases the operating rate of the plant.

The feature of the present invention is that when the water level of the 44 water in the second hot well of the side stream type condenser drops below the installed water level, the steam generation of the steam generator to which the condensed water is supplied is suppressed. There is a particular thing.

- A preferred embodiment of the present invention applicable to a single-water nuclear power plant will be described with reference to FIG. The cooling water in the reactor pressure vessel l is driven by the recirculation pump 18 and introduced into the reactor core (not shown) existing in the reactor pressure volume 41 through the unrecirculated F31 warehouse.

Although not shown, uranium-23, which is a fissile material,
fJ with 5 filled inside! , a large number of fuel-combined fuel rods are loaded into the reactor core.

The cooling water is heated by swallows generated by nuclear fission of Ura 7-235 while rising into the core, and becomes steam. This steam is guided through a main steam pipe 32 having two valves to a turbine 2 to which a generator 3 is connected. Steam exhausted from the turbine 2 is condensed in the condenser 4. The condensed water of this steam accumulates in the first hot well 5 of the condenser 4. , the condensed water in the first well 5 is guided into the second hot well 8 in the condenser 4 through the side stream distribution f33 by the drive of the side stream pump. The condensed water in the side stream piping 33'frRt'L is purified by condensate purification tj+t7, and further heated by the A air exhausted from the turbine 2 in the water heater 4, thereby increasing its temperature. The first hot well 5 and the second hot well 8 are
It is partitioned off by a partition wall 34. 2nd hot well 8
The condensed water inside can flow into the 41 real well 5 beyond the ma34. The condensed water in the second hot well 8 is supplied as water supply into the reactor pressure vessel 1 through the water supply pipe 35. That is, the condensate pump 9, the turbine, and the driven feed water pump 11 are driven, and the feed water in the second hot well 8 is heated by the low pressure feed water heating 610'J? The water is supplied to the reactor pressure vessel 1 by the high-pressure water supply IJrJ heater 13. A reactor pressure vessel 1 of a boiling water reactor is a single steam generator. The water supply pump 11 is driven by steam extracted by the extraction air f36 connected to the main steam pipe 32.

The water supply flow JtitIIJ to the reactor pressure vessel 1 is controlled by three-element control. That is, reactor pressure capacity a1
The measured values of the water level, f'l' 14 provided in , the = 11 The output signal of the control device 17 adjusts the opening degree of the pulp 29 which controls the supply ft of driving steam of the water feed pump 11.The water feed pump 12 driven by the motor is driven by the standby unit of the water feed pump 11. When you are there,
The water supply flow rate is controlled by adjusting the opening degree of a valve 28 provided on the discharge side of the water supply pump 12 using the output signal of the water supply control device 17.

The liquid level of the supplied water in the first hot well 5 of the condenser 4 is measured by a water level gauge 22 provided in the condenser 4. When the water supply level in the first hot well 5 drops below a predetermined value, the output signal of the water level gauge 22 is transmitted to the control #42.
6 and 270 actions close the spillover valve 24 and open the make-up water valve 25. Therefore, the supply of water in the side stream pipe 33 to the condensate water storage tank 23 is stopped, and the water in the condensate storage tank 23 is guided into the first hot well 5. In this way, the water supply level in the first well 5 is maintained at a predetermined level.

In this embodiment, the steam generation 7 prevents the operating rate from decreasing due to the liquid level in the second hot well 8 dropping below a predetermined value.
Suppression? It has an fflIn device. This control device is
Water level gauge 30 and control gc station 19 provided in condenser 4
It consists of

If the water supply flow rate in the water supply pipe 35 cannot be maintained at a specified level due to a malfunction of the side stream system pump, valve, or equipment, etc., the water supply return pipe connecting the water supply pipe 35 and the water dispenser 4 may be Water supply pipe 35 due to valve failure
In the 4th case where the water supply fL child becomes excessive, the second real well 8
Due to the loss of water supply within the second real well 8, the water supply level within the second real well 8 decreases.

Taking as an example a case where one of the two side stream pumps 6 in operation trips and one of the standby side stream pumps 6 does not start, the control when the water supply in the 1g2 hot well 8 is lost in this embodiment is explained. I will explain about it. Before that, the phenomenon of the transient state in which the IJ-Mbump 6 is activated will be explained. FIG. 3 shows the transient state. When one of the two side stream pumps 6 in operation drips, the amount of water supplied by that pump decreases as shown in characteristic 51. Along with this, the discharge t of the water supply from the sites 11 to 6 during other operations changes as shown in time 52, and the water supply (i
The amount also decreases as in characteristic 54A. After that, when one side stream Ponzoro, which is rarely in standby mode, is driven, the water supply flow rate discharged from that pump is characteristic 53.
The flow rate of water supplied into the second real well 8 also increases as shown in characteristic 54B. However, the water supply flow rate corresponding to the hatched area 55 surrounded by the required water supply flow rate 56 and the characteristics 54A and 54B becomes a mismatch filter. Therefore, the water level in the second hot well 8 is determined by the first water level L1 determined at the position of the upper end of the partition wall 34. water supply. The pushing pressure of the condensate pump 9 due to the supply of water with a volume of V? Sufficient amount can be secured.

If one side stream pump 6 trips and the spare side stream Ponzoro does not start, 8V′i, 3rd
There is no increase in the water supply flow rate as shown in time 53 in the figure, and the water supply liquid level in the second hot well 8 falls below the second water level L2. This drop in liquid level is the water level. 1l-30. The detection signal of the water level gauge 30 is input to the control device 19. At this time, the utilization device 19 completely reduces the rotational speed of the recirculation pump 18 and reduces the cooling water vrLi flowing through the core portion of the reactor pressure vessel 1. This reduction in the flow rate of the cooling water reduces the output of the reactor, suppresses the separate heat of the cooling water due to nuclear addition pAvc, and suppresses the amount of steam generation.

A reduction in the amount of steam generated leads to a reduction in the required flow rate i of feed water supplied into the reactor pressure vessel 1. Therefore, loss of water supply in the second hot well 8 can be avoided. Naturally, the amount of steam produced can be suppressed to a certain level depending on the water supply flow rate that can be supplied by one side stream pump 6. That is, characteristic 57 in FIG.
The generated steam flow rate (main steam flow rate) decreases as follows, and eventually the steam flow rate is held constant at characteristic 59. Area 5
8 is the decrease in steam flow rate. Therefore, the water supply level in the second hot well 8 is set to a predetermined value (for example, the second water level L2
) Even if it falls below, there is no need to scram the entire reactor, and the spelling rate of the boiling water nuclear power station will improve. In this implementation, 1. The recirculation pump 180 rotation speed was adjusted by the output signal of the BI'J# device 19, but the control rod 1 drive device (not shown) that operates all the 1fi II groaning rods installed in the reactor pressure vessel 1 is a full control device. The amount of steam generated may be suppressed by inserting a control rod into the reactor core in response to the output signal at t19.

In addition, in Figure 2, L3 is the lowest water level at the time of reactor power drop;
L is the minimum water level at which the condensate pump 9 can extract the water supply from the second real well 8, and L6 is the minimum water level at which the side stream pump 6 can extract the water supply from the first well 5.

The present invention can also be applied to cases where a side stream type condensate 4 is provided in the water supply piping of a steam generator provided in a /JO pressure water reactor and a fast breeder reactor. It can also be applied to steam power plants with boiler Kongo as a steam generator. In this case, the fuel flow rate supplied to the boiler may be adjusted using the output signal of the control device 19.

According to the invention, pla/to? Since there is no need to stop the plant, the operating rate of the plant can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a preferred embodiment of the present invention applied to a Si-teng water type nuclear power plant; Fig. 2 is a partially enlarged view of the side stream type condenser shown in Fig. 1; The figure shows the change in feed water flow rate in a transient state when one sidestream pump trips, and the figure 4 shows the temporality Δ showing the change in the steam flow rate when the embodiment shown in Figure 1 is applied. . 1... Reactor pressure vessel, 2... Turbine, 4...
Condenser, 5... First hot well, 6... Side stream pump, 8... Second real well, 9...
Condensate pump, 18°...Re Jt14 pop/p, 19...
City 111 Wholesale equipment, 30...Water level gauge, 33...Side stream piping, 35...Water supply agent Patent attorney Akira Takahashi z-・,=,=Lee゛,-

Claims (1)

[Claims] (i) a steam generator, a turbine to which the steam generated by the steam generator is guided, a first hotwell containing condensed water of the steam exhausted from the turbine, and a temperature rise of the condensed water in the first hotwell; A side stream condenser with a second real well led at the rear and a front d-pi second well.
In the method for controlling a steam generation plant comprising means for guiding the return condensed water in the hot well to the steam generator, when the water level of the condensed water in the conduit 2 hot well falls below the set water level, the A method for controlling a steam generation plant in which the #f feature is to suppress the amount of steam generated by a steam generator.