JPS6042501A - Nuclear reactor feed pump interlocking device - 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 reactor feed water pump interlock device for a boiling water nuclear power plant (hereinafter referred to as a BWR plant).

[Technical Background of the Invention] FIG. 1 shows a general configuration of a BWR plant. That is, a gas phase section in the upper part of the nuclear reactor 1 is communicated with a turbine 4 that drives a generator 3 through a main steam pipe 2 . The liquid phase part of the condenser 5 of the turbine 4 is connected to the suction side of the condensate pumps 6a to 6C installed in parallel, and the condensate pumps 6a to 6C
The discharge side is branched into two after being all at once.

One branch is connected to a turbine-driven reactor feed pump (hereinafter TDRFP) which is driven by the turbines 7a and 7b.
) 8a, 8b O) Communicated with the suction side. 9 in the diagram
′ indicates a conventional reactor feed water pump interlock device.
. In addition, the other branch is a motor-driven reactor feed water pump (hereinafter referred to as MDRF) driven by motors 10a and 10b.
P) It is connected to the suction side of 11a and 11b.

T'DRFP8a, 8b discharge side, discharge valve 12a
, 12b are provided and MDRFPI la.

On the discharge side of 1111, flow rate adjustment valves 13a, 13b and discharge valves 14a, 14b are provided in order from the pump side''/JX-.On the downstream side of the discharge valves 12a, 12b, 14a, 14b, a water supply header 15 is installed. The water supply header 15 is connected to the liquid phase portion of the reactor 1 through a water supply pipe 16.

Maiko, TDRFP8a, 8b, MDRF
A discharge pressure detector 17 is installed on the discharge side of Pl 1a and llb.
a, 1711.18a, and 18b are provided, and the water supply header 15 is provided with a water supply header pressure detector 19.

In the above configuration, steam generated in the nuclear reactor 1 reaches the turbine 4 via the main steam pipe 2, drives the turbine 4, and causes the generator 3 to generate electricity. The steam that has consumed energy in the turbine 4 is condensed into cold 1.0% water in the condenser 5, and this water is boosted in pressure by condensate pumps 6a to 6C and TDRFPs 8a and 8b, and then sent to the water supply header 15 and the water supply piping 16. is returned to the liquid phase of the nuclear reactor.

At this time, TDRFP8a, 8b (1) The turbine 7 is adjusted so that the discharge V can maintain the reactor water level constant.
It is controlled by adjusting the speeds of a and 7b.

The above is the state during rated operation, and in this state TDRF
If even one of P8a and 8b fails, the conventional reactor feed water pump interlock device 9 will shut down the motor 10.
a, 10b are immediately driven, MDRFPI 1a,
Start water supply as backup for TDRFP8a and 8b whose 1 lb tripped. At this time, the opening degrees of the flow rate regulating valves 13a and 13b are adjusted to keep the reactor water level constant.

In addition, the discharge valves 12a112b of TDRFP8a and 8b
is normally a manual valve and is manually closed in the BWR plan 1 to operating state when the TDRFPs 8a and 8b are stopped.

Its opening is done according to the following procedure. First, the turbines 7a and 7b are started and the TDRFP 8a is activated.

8b so that the indicated value of the discharge pressure detectors 17a, 171) and the indicated value of the water supply header pressure detector 19 are approximately equal.

Adjust the rotation speed of 8b. Here, the discharge valves 12a, 12
If b is opened manually, it will have almost no effect on the reactor water level.

Figure 2 shows the main functions of a conventional reactor feed water pump interrotter device 9. There are two types of TDRFP, 8a and 8b, and this figure shows TDRf-P8a. In order to prevent supercharging water to the reactor, if the reactor water level becomes higher than a certain set value (as shown in figure A), or to protect the pump, the setting fl is set at the suction pressure of TDRFP8a.
? If the TDRFP8a pump bearing oil pressure becomes lower than a certain set value (C)
, or when the turbine bearing oil pressure of the turbine 7a becomes lower than a certain set value (D), or in order to operate the TDRFP 8a within the range where water supply flow rate control is possible.
If the FP8a is inward operation (E) and its suction flow rate is lower than a certain setting (111 (F)), the turbine 7
A is rapidly stopped and TDRFP8a is tripped (G). In FIG. 2, AND does not indicate ant game 1, and OR does not indicate an OR gate. In addition, TDRFP8a is under load operation.
Water is supplied to TDRFP8a, and TDRFP
There is a pressure difference (E+) before and after the check valve 8a (not shown),
The determination is made based on the fact that the discharge valve 12a is fully open (E2). TD in the same way as 1 to lip of TDRFP8a above.
RFP8b is also tripped.

Furthermore, if TDRFP8a or TDRFP8b trips (
H1■), DRFP8a and 8b are under load (J
, K), if the water supply flow rate is lower than a certain set value (L) <', and if the reactor water level is not abnormally high (M), the two TDRFPs will not receive water. It was determined that one of the machines was either out of operation or inoperable, and the M
D F< FPllallb is automatically started. Note that one of the criteria for judgment is that the water level in the I-deuteron reactor is not high, so there is no risk of supercharging water.

[Problems with the background technology] In Figure 1, during the reactor rated power operation, two TDs
RFP8a and 8b are in operation, and two MDRF
When Pl 1a, 1 lb is in standby state, for example, T
Assume that the discharge valve 12a of the DRFP 8a becomes fully open due to a failure or erroneous operation. Then, the water supply flow rate of the TDRFP 8a becomes O, and the reactor water level decreases by that amount. In order to prevent this water level drop, water supply flow rate control (a
ll system (not shown) increases the flow rate of TORFP8b, but since the rated flow rate of the TDRFPI unit is approximately 50% of the feed water flow rate during reactor rated power operation, the TDRFP
It is not possible to completely compensate for the decrease in flow rate caused by 8a. Furthermore, the suction flow rate of the TDRFP 8a suddenly decreases when the discharge valve 12a is fully opened, but since the discharge valve is not fully opened, E
l is not established and TDRFP8a is operating under load (E)
It is not determined that Therefore, even if the suction flow rate is low or low (F), the 1-rip of TDRFP8a is not the same as R1.

Therefore, it is no longer possible to supply water commensurate with the amount of steam coming out of the reactor 1, and the reactor water level continues to fall, and when the reactor water level reaches the reactor 1-rip set value, the reactor goes into soucram. If the discharge valve 12a is closed for some reason, the backup M
Even though the DRFP is healthy, its automatic startup does not occur and a reactor scram occurs.

[Object of the invention] The present invention has been made based on the above circumstances, and is based on the TDRFP.
Even if the supply water supply and discharge valve is fully closed,
The purpose of this invention is to obtain a reactor feed water pump interlock device that automatically starts the MDRFP.

[Summary of the Invention] In the present invention, the above object is achieved by adding, as one of the TDRF P1 to lip conditions, that the discharge valve is fully open and the pressure difference before and after the opening is large.

[Embodiment of the Invention] FIG. 3 shows a main part of the functions of the present invention. In FIG. 3, the same reference numerals are omitted for the same parts as in FIG. 2. In the present invention, the discharge valve 12 of 'T D RFP
aThe conventional TD
In addition to the RFP trip condition, -c stage () is included.

That is, T D RF P 8 a , 'l''' 8
When either one of the discharge valves 12a or 12b is fully closed, the water supply flow rate decreases and the reactor water level drops. In addition, the rotation speeds of the turbines 7a and 7b are increased, and the output flow of the TDRF P whose output valve is not fully closed increases. However, although the discharge pressure of the TDRFP increases when the discharge valve is fully closed, the differential pressure across the discharge valve increases because the discharge valve is fully closed. Therefore, by adding the output of an AND gate that inputs the discharge valve fully open and the differential pressure in front and rear thereof to the conventional OR circuit, T D RF P can be reduced to 1 when the discharge valve is fully opened due to malfunction or erroneous operation.
- The MDRFP can be automatically activated.

[Effects of the invention] As is clear from the above, 1117.11 of Wang DRFP
Even if the valve is fully opened, the TDRFP can be tripped and the backup MDRFP can be automatically activated, so unnecessary reactor scrams do not occur and BWR Plan 1 Maintain good availability of ~:'x 1!7. Further, it is possible to prevent an adverse effect on the power system.

[Brief explanation of drawings]

FIG. 1 is a schematic system diagram of the RWR plant, FIG. 2 is a diagram that does not show the functions of the reactor feed water pump operating device, and FIG. 3 is a diagram showing the main part of an embodiment of the present invention. 8a, 8b ・TDRF P 9... Conventional reactor feed water pump interlock SUM1
0a, 10b-Ml) RF P 12a, 12b--Discharge valve application attorney Kikuchi 5 Part 2 Figure F7 Figure 3 t

Claims (1)

[Claims] It is installed in the reactor feed water pump operation device that operates the turbine-driven reactor feed water pump and the motor-driven reactor feed water pump, and is configured to monitor the reactor water level, the suction pressure of the turbine-driven reactor feed water pump, and the turbine-driven reactor water pump. The turbine-driven reactor feed water pump is tripped by either the minimum suction flow of the reactor feed water pump and the turbine drive during office operation, the turbine bearing oil pressure is low or the pump bearing oil pressure is low or low, and when tripping occurs, the motor-driven reactor feed water pump is automatically activated. A reactor feed water pump interlock characterized in that, as one of the trip conditions, the discharge valve of the turbine-driven reactor feed water pump is closed and the differential pressure before and after the discharge valve is large. Device.