JPS61180810A - Controller for number of pump - 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] [Field of Application of the Invention] The present invention provides a boiling water nuclear power generation plant comprising a condensate pump, a condensate boost pump, and a feed water pump.
Regarding control of the number of supply and condensate system pumps.

[Background of the invention]

FIG. 5 shows an overview of the feed/condensate system and the relationship with the pump number control device of the boiling water nuclear power plant.

The condensate in the condenser 1 is pumped out by the condensate pump 2, and the pressure and flow rate necessary to pass it through the grand condenser 5, the condensate filtration value ff16, and the condensate desalination device 7 are maintained. is ensured.

The condensate boost pump 8 boosts the pressure of condensate that has been depressurized by upstream equipment, passes through the low-pressure feed water heater 11, and then supplies the water to the feed water pump 12.
is supplied to. Furthermore, the pressure is increased by the feedwater pump 12 to the pressure necessary to feed water to the nuclear reactor 15 via the high-pressure feedwater heater 14, and a flow rate is produced.

Regarding mutual interlock between pumps in such a system configuration, conventionally, one condensate pump standby unit is automatically started when the low discharge pressure detector 4 of one of the condensate pumps operates or trips. Similarly, when the discharge pressure low detector 10 of each condensate booster pump operates or trips, one condensate booster pump standby unit is automatically started, and when the upstream pump (IJ) is activated, each downstream pump To prevent the inlet pressure from falling below the required pressure, the number of upstream pumps and downstream pumps are controlled by circuit breakers 3 and 9 for each pump drive motor.
．． A pump operation number control device #L16 is installed which limits the number of pumps in operation so that the number of pumps in operation on the downstream side is always equal to or less than the number of pumps on the upstream side based on the open/closed state of pumps 13.

In the conventional device, the backup device is automatically started only when the pump in which the pump discharge pressure detector 4.10 is installed fails, and the gland condenser 5 and condensate filtration f7, which are the pump upstream devices, are activated automatically.
The discharge pressure of the condensate boost pump is detected to detect a high differential pressure derived from a malfunction in the condensate desalination device 7 or the low-pressure feed water heater 11, that is, a decrease in the pressure at the inlet side of the condensate boost pump, which is the downstream pump. Since the condensate booster pumps cannot be detected by the unit 4.10, there is a risk that all the condensate boost pumps will trip due to the drop in inlet pressure.

[Purpose of the invention]

An object of the present invention is to provide a more excellent device for controlling the number of pumps in operation.

[Summary of the invention]

A drop in pump inlet pressure due to a malfunction in the upstream device of the pump cannot be verified by checking the pump discharge pressure, and the best way to deal with this is to increase the upstream pressure at the pump inlet, rather than automatically starting the pump's backup device. It is more rational and effective to automatically start the standby side pump.
Furthermore, since bong inlet pressure detection has less pulsation than pump discharge pressure and is easier to detect, the upstream pump backup device is automatically activated when the pump inlet pressure decreases.
achieve this purpose.

[Embodiments of the invention]

1 to 4 show an embodiment of the present invention.

FIG. 1 shows an overview of the feed/condensate system of the present invention and its relationship with a pump number control device.

Compared to FIG. 5, a condensate boost pump inlet pressure detector 17 and a water supply pump inlet pressure detector 18 are added.

The control logic applied to the present invention't-t-condensate pump condensate boost pump and water supply pump is shown in FIGS. 2, 3 and 5.
As shown in the figure.

The control logic of each pump is based on the pump switch 19, the supply and condensate system process conditions 24 to 42, the OR circuit 21, and the
The configuration is dependent on an ND circuit 22, a NOT circuit 23, and a pump motor breaker 20.

Among these control logics, the pump number control device 16
Includes the part indicated by the dashed-dotted line.

Next, the control logic of the condensate pump shown in FIG. 2 will be explained.

For example, if the condensate pump (A) switch 19 is in the automatic position, that is, if it is on standby as a standby device, the downstream pump is ``low input pressure of any of the condensate boost pumps (A) to (C)''.
Signal 32 or other similar pumps in operation. “Low discharge pressure detector 27 of either condensate pump (B) or (C)
, or ``Trip of either condensate pump (B) or (C)''
Signal 26 or signal 39 "The number of operating condensate pumps and the number of operating condensate booster pumps are equal" is generated, and "
When the input pressure low signal 38 of any one of the water supply pumps (A) to (C) is generated, the water supply pumps (A) to (C) are automatically activated.

On the other hand, the trip condition is that the condenser hotwell water level is low.
Signal 24 and signal 25 are present when the pump is in operation.
Even if an automatic start condition occurs, the NOT circuit 23 forces the system to stop.

Next, the condensate boost pump control logic shown in FIG. 3 will be explained.

For example, when the switch 19 of the condensate boost pump (A) is in the automatic position, that is, in the standby state as a standby machine, the signal 40 "The number of condensate pumps in operation is greater than the number of condensate boost pumps in operation" is generated. D, and “water supply pumps (A) to (C
) Any person with low pressure.

When the signal 38 or the similar pump in operation in the pond generates the "low discharge pressure of any condensate boost pump (B) (C1)" signal 33, it is automatically started.

The comparison of the number of condensate pumps in operation and the number of condensate booster pumps in operation is a component of the automatic start condition, as well as the condition for automatic stop of the condensate booster pump and the unbalanced number of pumps between upstream and downstream pumps. ``The number of condensate pumps in operation is less than the number of condensate booster pumps in operation'' signal 41 is a measure to prevent overload operation of the condensate pump, and the inlet pressure of the water supply pump or the condensate booster pump in the pond has decreased. In this case, if the standby unit of the condensate boost pump is started unconditionally, it will be stopped again depending on the condensate boost pump automatic stop condition.

In addition, as a condition for automatically starting the condensate booster pump, there is a trip'' signal 26 for either the condensate pump (B) or (C) when the same type of pump is tripping while the pond is in operation. The reason why the condition for comparing the number of boost pumps is not taken into consideration is that when a condensate boost pump trips, the number of condensate pumps in operation always increases.

In addition, “condensate boost pump (A) input pressure low” signal 28,
When the “condensate boost pump (A) electrical failure” signal 29 and the “condensate boost pump (A) l) lubricant condition” signal 30 occur, the condensate boost pump will be forced to stop and then automatically stopped. This means that if an automatic stop signal is generated during pump operation, the pump will stop, but when the automatic stop signal disappears and an automatic pump start signal is generated, the pump will automatically start again. On the other hand, forced stop means that the pump has stopped and cannot be started until the failure is repaired.

Next, the water pump control logic will be explained with reference to FIG.

For example, when the water supply pump (A) switch 19 is in the automatic position, that is, in the standby state as a standby unit, if a similar type of pump in operation in the pond generates a signal indicating "trip of either water supply pump (B) or (C)", the automatic to start.

On the other hand, when the same number of feed water pumps and condensate boost pumps are operating, if the condensate boost pump trips, the condensate boost pump becomes overloaded. “If the signal 42 is generated, the water supply pump (A) is automatically stopped.

Furthermore, the “water supply pump (A) input pressure low” signal 34;
Or, "Water pump (A) electrical failure" signal 35, or "
When the water supply pump (person) and other trip conditions signal 36 occurs, the water supply pump (A) is forcibly stopped.

〔Effect of the invention〕

According to the present invention, the complicated behavior of the condensate pump automatic start after IJ tube (condensate pump), the condensate boost pump, and the water feed pump automatic start after the unbalanced number of condensate boost pumps and water supply pumps has stopped. It can be prevented.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an overview of the supply/condensate system of an embodiment of the present invention and its relationship with the pump number control device, Fig. 2 is a diagram showing the control logic of the condensate pump, and Fig. 3 is a diagram showing the relationship with the pump number control device. , Fig. 4 is a diagram showing the control logic of the condensate boost pump, Fig. 4 is a diagram showing the control logic of the feed water pump, and Fig. 5 is an overview of the feed/condensate system of a boiling water nuclear power plant and a pump number control device. FIG.

Claims (1)

[Scope of Claims] 1. In a boiling water nuclear power plant, when operating between feed and condensate system pumps that are composed of a condensate pump, a condensate boost pump, and a feed water pump from the upstream side, the condensate Even if one of the condensate pump standby units is automatically started due to a drop in the inlet pressure of the boost pump, and even if the condensate boost pump standby unit is started up due to a drop in the inlet pressure of the water supply pump, the condensate If it is predicted that the inlet pressure of the boost pump will not further decrease, one of the backup units of the condensate boost pump is automatically started, and the backup unit of the condensate boost pump is automatically activated due to the decrease in the inlet pressure of the feed water pump. If it is expected that the inlet pressure of the condensate boost pump will further decrease when the condensate boost pump is started up, one backup unit of the condensate pump will be automatically started, and then one backup unit of the condensate boost pump will be activated. , a pump number control device characterized by automatic startup. 2. In claim 1, it depends on activation of each of the condensate booster pump standby machines. A device for controlling the number of pumps, wherein a predicted decrease in the inlet pressure of the condensate boost pump is automatically determined based on the number of operating condensate pumps and the condensate boost pump.