JPH08110392A - Reactor water supply facility - Google Patents

Abstract

PURPOSE: To standardize water supply pumps and improve maintainability and arrangement of components by providing more water supply pumps with almost the same capacity than a specific number. CONSTITUTION: This reactor water supply equipment is constituted of 4 or more systems of water supply pumps 11 to 14 with ca. 33% capacity of rated flowrate per a system. The pumps 11 to 14 are driven with motors 15 to 18. The rotation shaft of the motors 15 to 17 are connected to the corresponding rotation shaft of pumps 11 to 13 by way of corresponding fluid coupling 19 to 21. Each fluid coupling 19 to 21 variably controls transmission torque and changes the revolution number of the pumps 11 to 13. The pump 14 is operated in a constant speed with the motor 18 by way of a speed increaser 23 and water supply rate is controlled with a control valve 90 in the discharge side. In the front and back of the pumps 11 to 14, gate valves 81 to 88 are provided. Among four systems, one system of the pump 14 driven with the motor 18 is a standby system and is in standby state during normal operation. Other three systems of pumps 11 to 13 are operating systems driven in normal operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system facility for a nuclear reactor plant, and more particularly to a reactor water supply facility for controlling the flow rate of water supplied to the reactor.

[0002]

2. Description of the Related Art In a reactor plant, for example, a boiling water reactor of 700 MWe class or higher, as a water supply facility for the reactor, as shown in FIG.
A typical configuration is a combination of two systems of a steam turbine driven feed water pump of% capacity and two systems of an electric motor driven feed water pump of 25% capacity of the rated flow rate, which is started as a backup when starting / stopping or when one turbine drive water feed pump fails. is there.

The turbine-driven feed water pump extracts the steam flowing into the main turbine to drive the turbine directly connected to the pump, and controls the steam flow rate to adjust the turbine rotation speed to control the feed water flow rate. The electric motor driven water supply pump is driven by a constant speed electric motor, and controls the water supply flow rate by adjusting the opening of a water supply adjustment valve provided on the discharge side of the pump. The water supply system for such a boiling water reactor is equipped with the following control system. Incorporating three kinds of signals of feed water flow rate, main steam flow rate and reactor water level into the water level controller and comparing and judging with the water level set value, speed control of the turbine driven water feed pump or opening of the water feed adjustment valve of the electric motor driven water feed pump. Temperature control, the feed water flow rate is automatically adjusted and controlled so as to maintain a predetermined reactor water level.

Further, as described in Japanese Patent Application Laid-Open No. 6-3491, a common water supply pump driven by a synchronous motor having a variable rotation speed using a thyristor inverter, and an auxiliary water supply driven by an induction motor having a fixed rotation speed. There is also an example of a pump.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the reactor water supply system in which the turbine driven water supply pump and the electric motor driven water supply pump are combined, there are the following problems regarding the turbine drive system.

The turbine-driven feed water pump is arranged in the vicinity of a main turbine that extracts steam for driving and a main condenser that condenses steam discharged from the turbine. Therefore, the radiation dose in the area where the water supply pump is located is high,
Due to the shield design, it is divided into areas that do not require entry during normal operation. Therefore, the equipment cannot be accessed during the operation of the reactor, and maintenance work cannot be performed during the operation. Also,
Due to restrictions on the arrangement of the main turbine and the main condenser, the degree of freedom of arrangement within the turbine building is limited. Further, the lubricating oil system and hydraulic control system required for controlling the turbine-driven feed water pump have a large number of parts, which increases the amount of maintenance and inspection work.

In addition to this, in the reactor water supply system in which the turbine driven water supply pump and the electric motor driven water supply pump are combined, the capacity of the water supply pump of the normal system is different from that of the water supply pump of the standby system. It is necessary to manufacture a water supply pump.

Further, in the example described in the above-mentioned Japanese Patent Laid-Open No. 6-3491, all the water supply pumps are driven by an electric motor, but the capacity per water supply pump in the regular system is the rated water supply flow rate. 50% of However, when applied to a large reactor of 1350 MWe class, for example, the capacity of the electric motor for driving the feed water pump is about 11000 kW.
Will exceed the current production record. It is possible to increase the capacity of the electric motor by making the small electric motor tandem, but this is not preferable because it increases the installation space, the quantity and cost.

The object of the present invention is to standardize the water supply pump and
It is to provide a reactor water supply facility that can improve the maintainability and layout of equipment.

[0010]

[Means for Solving the Problems] The above object is to equip a reactor water supply path with in parallel a single standby system including a water supply pump and a water supply flow rate adjusting valve, and at least three service systems including a water supply pump. A reactor water supply facility, wherein each of the water supply pumps is a water supply pump driven by an electric motor and has a substantially equal capacity to each other, and at least two systems of the regular system are rotation speeds of the water supply pump. It is achieved by a reactor water supply facility characterized in that it is provided with a pump rotation speed varying means for controlling the.

[0011]

[Function] By setting the capacities of the water supply pumps of the respective systems to be substantially equal to each other, the water supply pumps having the same specifications can be used in the respective systems, and the water supply pump can be standardized. Therefore, the manufacturing of the water supply pump becomes easy.

Further, unlike the conventional combination of the turbine driven water feed pump and the electric motor driven water feed pump, since all the water feed pumps are driven by the electric motor, the number of electric motors increases, but the turbine or steam for driving the water feed pump is increased. Pipes and valves can be deleted.

Therefore, the water supply pump can be separated from the main turbine and the main condenser in the region where the radiation dose is low, and the degree of freedom of arrangement is improved. In addition to this, since the requirements for the shield design are reduced, the accessibility to the equipment during operation is improved and the maintainability of the water supply facility is improved. Compared to the turbine drive system, the number of parts of the equipment that adjusts the rotation speed of the electric motor and pump is smaller, and the maintenance and inspection work volume is also reduced.

Further, since the pump capacity per system is reduced by using four or more water supply pumps, even when it is applied to a large reactor, an electric motor within the actual production range can be used. The property is also easy, and it is possible to suppress an excessive increase in the amount of material such as tandemization.

Since the feed water flow rate is small at the beginning, the control response of the feed water flow rate adjustment by the variable speed of the feed water pump is lower than that by the flow rate adjusting valve, so that the flow rate adjustment is performed in the standby system or It is configured by the operation of a plurality of systems including the standby system and the opening of the flow rate adjusting valve of the standby system and the like.

[0016]

[Example] A reactor water supply system according to an embodiment of the present invention,
This will be described with reference to FIGS. 1, 3 and 4.

As shown in FIG. 1, the target reactor water supply system is composed of four systems of water supply pumps 11 to 14 each having a capacity of about 33% of the rated flow rate. The water supply pumps 11 to 14 are driven by electric motors 15 to 18. The rotary shafts of the electric motors 15-18 correspond to the corresponding fluid couplings 19-2.
1 is connected to the rotary shafts of the corresponding water supply pumps 11 to 13. Each fluid coupling variably adjusts the transmission torque from the electric motor to the water supply pump. Therefore, the rotational speed of the water supply pump can be changed by using the fluid coupling. Specifically, the rotational speeds of the water supply pumps 11 to 13 are variably adjustable by changing the positions of the rake pipes of the fluid couplings 19 to 21. In addition, the water supply pump 14 is a gearbox 23.
It is operated at a constant speed by the electric motor 18 via. By controlling the opening degree of the water supply adjusting valve 90 provided on the discharge side of the water supply pump 14, the flow rate of the water supply discharged from the water supply pump 14 is adjusted.

Gate valves 81 to 88 are provided before and after the water supply pumps 11 to 14, respectively. Of the four systems, one system of the water supply pump 14 driven by the electric motor 18 is a standby system and is in a standby state during normal operation. Remaining water supply pump 1
The three systems 1 to 13 are normal systems that are driven during normal operation.

FIG. 3 shows a schematic system of a boiling water reactor plant using the reactor water supply system of the embodiment shown in FIG.
The cooling water whose pressure has been increased by the water supply system water supply pumps 11 to 13 passes through the water supply pipe 59, is heated to a predetermined water supply temperature by the high-pressure water supply heater 58, and is then supplied to the nuclear reactor 51.
The cooling water is heated in the core to become steam, and the main steam pipe 6
0 to the high pressure turbine 52. The steam discharged from the high-pressure turbine 52 is guided to the low-pressure turbine 54 via the moisture separation heater 53. The steam discharged from the low-pressure turbine 54 is condensed into a condensate by the condenser 55, passes through the condensate pump 56, the low-pressure feed water heater 57, and returns to the feed water pump of the feed water system.

Signals from the flowmeters 71 to 74 provided in the downstream pipes of the water supply pumps 11 to 14, the water level meter 75 provided in the reactor 51, and the flowmeter 76 provided in the main steam pipe 60 are also output. In addition, the rake pipe positions of the fluid couplings 19 to 21 are controlled to adjust the rotation speeds of the water supply pumps 11 to 13, or the opening of the water supply adjustment valve 90 is adjusted for the water supplied from the water supply pump 14. The reactor 5
1 is provided with a water supply control system 77 for controlling the flow rate of water supply. Such control of the feed water flow rate controls the water level in the nuclear reactor 51.

In this embodiment, when water supply is started when the reactor is started, first, the water supply pump 14 which is a standby system is started to gradually increase the opening degree of the water supply adjusting valve 90, and Increase the supply water flow rate. Gate valves 84 and 88
Is fully open. Other gate valves 81-83, 85-8
7 is fully closed, and the water supply pumps 11 to 13 are stopped. When the water supply adjusting valve 90 is fully opened, the water supply flow rate is 33%. After that, the water supply pump of one system of the regular system, for example, the water supply pump 11 is started. Gate valves 81 and 85 are fully opened. By controlling the rake pipe position of the fluid coupling 19 by the water supply control system 77, the rotation speed of the water supply pump 11 is gradually increased. As the number of rotations increases, the water supply flow rate will correspondingly increase. When the water supply flow rate from the water supply pump 11 reaches 33%, the water supply pump 12 is then activated. Gate valves 82 and 86 are fully open. Like the water supply pump 11, the water supply pump 12 gradually increases in rotational speed. The increase in the water supply flow rate by the water supply pump 12 causes the water supply control system 77 to decrease the opening degree of the water supply adjusting valve 90. However, the total water supply flow rate is maintained at 66%. When the water supply flow rate discharged from the water supply pump 12 reaches 33%, the water supply adjustment valve 90 is fully closed and the sluice valve 84
And 88 are also fully closed. In this way, the switching from the water supply system such as the standby system to the water supply system of the regular system is completed when the reactor is started. After that, the remaining water supply pump 13 of the water supply system of the regular system is activated, and the water supply flow rate becomes 100%. Gate valves 83 and 87 are fully open. When the reactor is shut down, the flow rate of feed water is reduced by the reverse operation.

As described above, when the feed water flow rate at the time of starting the reactor is small, the reason why the feed water pump 14 such as the standby system is started to control the opening degree of the water feed adjusting valve 90 to increase the feed water flow is This is because the opening degree control has better control responsiveness and controllability at the time of the water supply flow rate than the rotation speed control of the water supply pump in the regular system. Further, during normal operation (during rated operation) of the nuclear reactor, the water supply pumps 11 to 13 whose rotation speeds can be controlled are started, so that electric energy for rotating these water supply pumps can be effectively used. Even if the water supply adjusting valve 90 is fully opened, pressure loss is caused by the gate valves 81 to 81.
Since it is larger than 88, the lift of the water supply pump 14 is set higher than the respective lifts of the water supply pumps 11 to 13 by the pressure loss of the water supply adjusting valve 90. Since the rated water supply flow rates of the respective water supply pumps are the same, the water supply pump 14 consumes more electric energy than the water supply pumps 11 to 13 because the head is set high. Therefore, during normal operation, it is more energy efficient to control the water supply by controlling the rotation speed of the water supply pump. In this embodiment,
Since the rotational speeds of the three systems of water supply pumps are controlled during normal operation, electric energy can be used most efficiently.

In this embodiment, the capacity of each of the water supply pumps 11 to 14 is 1/3 of the rated flow rate of the entire water supply facility, that is, about 3
It is set equal to 3%. For this reason, it is possible to use water supply pumps with the same specifications in each system, which enables standardization of water supply pump designs. Since it is only necessary to manufacture water supply pumps having the same specifications, it is easy to manufacture them.
Parts used for maintenance and inspection can be shared by each water pump. Since each of the three regular systems is provided with a means for variably controlling the rotation speed of the water supply pump, that is, a fluid coupling,
It is possible to smoothly change the water supply flow rate per water supply pump from the low flow rate state immediately after starting the water supply pump to the rated flow rate.

Comparing the physical quantity of a conventional reactor water supply facility equipped with a turbine-driven water supply pump and an electric motor-driven water supply pump with that of this embodiment, the number of water supply pumps is the same, but this embodiment is 33% of the total water supply capacity
Therefore, it is possible to suppress an excessive increase in the electric power of the electric motor that drives the water supply pump, and the amount of material is significantly reduced as compared with the conventional case.

When this embodiment is applied to a 1350 MWe class reactor plant, the electric motor capacity is about 8000 kW.
Becomes Since the capacity of the electric motor is within the range of actual production of a single electric machine, development of a new large electric motor and tandemization of a small electric motor are unnecessary, and an increase in the physical quantity of the electric motor can be suppressed. Also, the total installed capacity of the water supply pump is 150% of the conventional capacity.
Can be reduced to 133%. In addition, all water supply pumps 1
Since 1 to 14 are driven by an electric motor, the quantity of electric motors and three fluid couplings is increased as compared with conventional equipment, but two turbines and steam pipes / valves attached to a turbine driven feed pump can be deleted, It becomes compact.

As a result, the water supply pumps 11 to 14 can be separated from the main turbine and the main condenser in a region where the radiation dose is low, and the degree of freedom in layout design is improved. At the same time, the requirements for shielding design are reduced, so that the accessibility to the operating equipment is improved and the maintainability of the reactor water supply facility is improved.

Further, the electric motors 15 to 18 and the fluid coupling 19
The number of parts of equipments up to 21 is smaller than that of the turbine drive system, and the amount of maintenance and inspection work is also reduced. Further, if one of the three water supply pumps 11 to 13 operating during normal operation trips for some reason, the water supply pump 14 in the standby state is activated.

FIG. 4 shows a case where the water supply pump 12 in FIG. 1 trips. When a signal from a flow meter (not shown) provided in the system of the water supply pump 12 detects that the water supply pump 12 has tripped, the water supply control system 77 fully closes the gate valves 82 and 86 of the system. And At the same time, the water supply control system 77 starts the electric motor 18 in the standby state to drive the water supply pump 14, and fully open the sluice valves 84 and 88 and the water supply adjusting valve 90 to obtain a flow rate of about 1/3 of the entire equipment. Can be secured. Electric motor 1
By driving 8 to start the water supply pump 14 of the standby system, it is possible to suppress a large water level fluctuation such as reaching the scrum level water level of the nuclear reactor as in the conventional case, so even when one water supply pump trips, The operation of the nuclear reactor can be continued and the operating rate of the nuclear reactor equipment can be improved.

In the conventional standby system of the reactor water supply system, two electric motor driven feed pumps having a capacity of 25% of the rated flow rate were used, but in the present embodiment, the standby system is one system, and the standby system is The control method is simplified.

Thus, in this embodiment, about 33% × 4
By constructing the reactor water supply equipment with a system electric motor driven water supply pump (three system water supply pumps are variable speed operation system by fluid coupling control, one standby system water supply pump is constant speed operation system) In addition to standardizing the water supply pump, it is possible to suppress an excessive increase in motor power.
In addition, the turbine and steam pipes / valves associated with the conventional turbine-driven water feed pump can be deleted without excessively increasing the amount of equipment, which increases the degree of freedom in arranging the water feed pump in the turbine building and increases the The maintainability can be improved and the water supply facility can be rationalized.

In addition to this, since one system of the water supply pump is used as a standby machine, even when one of the water supply pumps of the regular machine is tripped, it is possible to suppress a drastic drop in the reactor water level that would reach the scrum level, and to reduce the reactor water level. Contributes to improving the operating rate of equipment.

Another embodiment of the present invention will be described with reference to FIG.

Similar to the embodiment shown in FIG. 1, the target reactor water supply equipment is composed of four systems of circulating water supply pumps 11 to 14 having a capacity per system of about 33% of the rated flow rate of the entire equipment. It The water supply pumps 11 to 14 are electric motors 15 to
Driven by 18. In this embodiment, the water supply pump 1
The fluid couplings 19 and 20 are provided for adjusting the flow rates of the fluid couplings 1 and 12, and the rotational speeds of the water supply pumps 11 and 12 are controlled by changing the positions of the rake pipes of the fluid couplings 19 and 20. Further, the water supply pumps 13 and 14 are operated at a constant speed by the electric motors 17 and 18 via the speed increasers 24 and 25. Water supply adjusting valves 89, 90 provided on the discharge sides of the water supply pumps 13, 14
The feed water flow rate is adjusted by controlling the opening degree of. Gate valves 81 to 88 are provided before and after the water supply pumps 11 to 14, respectively. Of the four systems, the system of the water supply pump 14 driven by the electric motor 18 is a standby system and is in a standby state during normal operation.

In this embodiment, as shown in FIG.
It is equipped with a feedwater control system that controls the reactor water level based on the three elements of the reactor water level and the main steam flow rate, and has a rake pipe position control circuit for the fluid coupling and a feedwater control valve control circuit based on the signal from the water level controller. This water supply control system can switch the single element control of only the reactor water level and the above three element control according to the operation mode (start-stop, normal operation) of the reactor.

Next, the operation in this embodiment will be described. First, at the time of starting the reactor, the system of the feed water pump 14 driven by the electric motor 18 is used. The water supply pump 14 is operated at a constant speed, and the opening of the water supply adjusting valve 90 is adjusted to gradually increase the water supply flow rate. At this time, even if the system of the water supply pump 14 cannot be started for some reason, the system of the water supply pump 13 driven by the electric motor 17 is started, and the opening of the water supply adjusting valve 89 is adjusted to gradually increase the water supply flow rate. Can be increased. As described above, since there are two systems provided with the water supply regulating valve, failure to start the water supply pump can be avoided, and reliability at the time of starting the reactor is improved.

At the time when the reactor power reaches about 10%,
The system of the water supply pump 13 driven by the electric motor 17 is also operated, the opening degree of the water supply adjusting valve 89 is adjusted, and the water supply flow rate is further increased. In such a low reactor power output, in the feed water control system shown in FIG. 6, single element control is performed only by the reactor water level to control the opening of the feed water adjusting valves 89 and 90.
Adjust the water supply flow rate.

The feedwater pumps 11, 12 driven by the electric motors 15, 16 are connected to the fluid couplings 19, 2 as the reactor output increases.
Output that enables stable variable speed operation by 0 (for example, 30 to
40%), the system of the water supply pumps 11 and 12 is operated and the stop operation of the system of the water supply pump 14 is started. After that, the water supply regulating valve 89 of the system of the water supply pump 13 is fully opened, and the number of rotations of the water supply pumps 11 and 12 is increased to increase the rated water supply flow rate.
Approximately 33% x 3 systems are transferred to the normal operating state.

During normal operation, two systems are normally used to operate the water supply pump at a variable speed using the fluid coupling, and one system is operated to operate the water supply pump at a constant speed (the flow rate is controlled by the water supply adjusting valve 89).
Since they are operated in combination, the feed water flow rate can be smoothly changed from the low flow rate state immediately after startup to the rated flow rate. Furthermore, the drive system of the water supply pump is diversified, and the reliability of the water supply equipment is improved.

During normal operation, fluctuations in reactor output occur,
When the reactor water level fluctuates, the feedwater control system shown in FIG. 6 controls the reactor water level, the main steam flow rate, and the feedwater flow rate to control the feedwater flow rate so as to satisfy the water level set value. . At this time, the rake pipe position control of the fluid couplings 19 and 20 provided in the system of the water supply pumps 11 and 12 is performed with priority over the opening control of the water supply adjustment valve 89 of the system of the water supply pump 13. As a result, the water supply adjusting valve 89 can be operated to be fully opened in the normal state, so that the power loss in the water supply adjusting valve 89 can be reduced and the failure due to the vibration of the valve can be prevented.

If one of the three system water supply pumps 11 to 13 operating during normal operation trips for some reason, as in the embodiment of FIG.
The system of the water supply pump 14 in the standby state is started. The standby water supply pump 14 and the water supply adjustment valve 90 can prevent a significant decrease in the water level that would reach the scrum level water level of the reactor, so that the operation of the reactor can be continued even when one water supply pump trips. The operating rate of furnace equipment is improved.

In the present embodiment, in addition to the standby system, one system for controlling the feed water flow rate by the flow rate adjusting valve is provided in the regular system, so that the water supply pump 14 of the standby system does not start due to an abnormality when the reactor is started. In this case, the feed water pump 13 of the regular system is started, and the feed water flow rate is stably controlled by controlling the opening degree of the flow rate adjusting valve 89 having good controllability at the time of low flow rate at the time of starting the reactor, as in the above-described embodiment. can do. At the time of normal operation of the nuclear reactor, since one water supply system controlled by the flow rate adjusting valve is used, the utilization efficiency of electric energy is lower than that of the above-mentioned embodiment, but the rotation speed of the water supply pump is controlled. Since two water supply systems are used, the utilization efficiency of electric energy is high.

Thus, in this embodiment, about 33% × 4
The water supply pump of the system is driven by a motor (two system water supply pumps are variable speed operation system by fluid coupling control, the other two system water supply pumps are constant speed operation system). Standardization is possible,
It is possible to suppress an excessive increase in motor power.

Although the quantity of the electric motors and the two fluid couplings is increased as compared with the conventional equipment, the two turbines and the steam pipes / valves associated with the turbine driven water feed pump can be eliminated.
For this reason, the degree of freedom in designing the arrangement of the water supply pumps in the turbine building and the maintainability of the water supply equipment are improved, and the water supply equipment can be rationalized.

Regarding the operability as well, since there are two systems provided with the water supply regulating valve, it is possible to avoid a failure in starting the water supply pump at the time of starting the reactor.

Further, as the normal system, the system which is operated at a variable speed by the fluid coupling control and the system which is operated at a constant speed by the water supply adjusting valve control are operated in combination, so that the drive system of the water supply pump is also diversified. , The reliability of water supply equipment is improved.

In addition to this, as in the embodiment of FIGS. 1 and 4, one system of the water supply pump is used as a standby machine, so even when one water supply pump of a regular machine trips, the reactor water level that will reach the scrum level. It is possible to suppress a drastic decrease in fuel consumption and contribute to the improvement of the operating rate of reactor equipment.

Another embodiment of the present invention will be described with reference to FIG. Similar to the embodiment shown in FIG. 5, the target reactor water supply equipment is composed of four systems of circulating water supply pumps 11 to 14 each having a capacity of about 33% of the rated flow rate. In this embodiment, the thyristors 21 and 22 connected to the electric motors 15 and 16 are used to control the rotational speeds of the electric motors 15 and 16 that drive the water supply pumps 11 and 12.
The thyristors 21 and 22 are means for variably controlling the rotation speed of the water supply pump. The structure of the water supply equipment other than these is
This is similar to the embodiment shown in FIG. Also in this embodiment, a water supply control system similar to that shown in FIG. 6 is provided.

Since the operation of this embodiment is the same as that of the embodiment shown in FIG. 5, its explanation is omitted. Another embodiment of the present invention will be described with reference to FIG. The target reactor water supply facility is composed of five systems of water supply pumps 31 to 35 each having a capacity of about 25% of the rated flow rate. Water pump 3
1 to 33 are electric motors 36 to 36 via fluid couplings 41 to 43.
Driven at 38. The water supply pumps 34, 35 are driven by electric motors 39, 40 via the speed increasing gears 9, 10. Gate valves 91 to 100 are installed in front of and behind the water supply pumps 31 to 35, respectively.
On the discharge side of the water supply pumps 34, 35, the water supply adjustment valve 10
1, 102 are provided. Of the five systems, the system of the water supply pump 35 driven by the electric motor 40 is in a standby state during normal operation.

This embodiment also has a water supply control system almost similar to that shown in FIG.

Comparing the equipment of this embodiment with a conventional reactor water supply equipment in which a turbine driven water supply pump and an electric motor driven water supply pump are combined, the number of water supply pumps increases from four to five. The total installed capacity is reduced from 133% to 125%, and the driving electric power of the electric motor can be made almost equal to that of the electric motor driven feed pump of the conventional standby system, so that the almost same electric motor as that used conventionally can be used. The operation of this embodiment is almost the same as that of the embodiment shown in FIGS.

[0051]

According to the invention of claim 1, the water supply pumps having the same specifications can be used in each system by setting the capacities of the water supply pumps to be substantially equal, and the water supply pump can be standardized. At the same time, spare parts used during maintenance can be shared. Further, even when it is applied to a large-scale furnace, an electric motor within the production performance range can be used, so that an excessive increase in the electric motor quantity can be suppressed.

Further, unlike the conventional combination of the turbine driven water feed pump and the electric motor driven water feed pump, since all the water feed pumps are driven by the electric motor, the steam for the turbine driven water feed pump becomes unnecessary and the steam pipe can be deleted. Along with this, the water supply pump can be separated from the main turbine and the main condenser in the area where the radiation dose is low, which improves the degree of freedom in arrangement and reduces the requirements for shielding design. The accessibility to the equipment is improved and the maintainability of the water supply facility is improved.

Compared with the turbine drive system, the number of parts of the device for adjusting the rotation speed of the electric motor and pump is smaller, and the maintenance and inspection work amount is also reduced.

Further, a normal system equipped with a pump operating at a variable speed and a standby system equipped with a feed water flow rate adjusting valve are operated in combination to smoothly change from a low flow state immediately after startup to a rated flow rate. be able to.

According to the invention of claim 2, in addition to the effect by the invention of claim 1, in the range of the normal operation state, the rotation speed control of the feed pump which is operated at a variable speed is operated at a constant speed. By prioritizing the opening control of the water supply regulating valve in the system with a water supply pump, the water supply regulating valve can be operated in a fully open state during normal operation, reducing the pressure loss due to the water supply regulating valve and reducing the valve It is possible to prevent breakdown due to vibration and improve the reliability of equipment.

According to the third or fifth aspect of the invention, in addition to the effect of the first or second aspect of the invention, the pump rotation speed varying means is the rotation speed control means of the electric motor or the water supply pump from the electric motor. Since it is a means for controlling the number of revolutions transmitted to the engine, the number of revolutions can be easily changed in the operating range such as when the reactor output increases, so that the operability of the reactor water supply facility is stabilized.

According to the invention of claim 7, in addition to the effect of the invention of any one of claims 1, 2, 3 and 5, the pump of the standby system can be easily driven at a constant speed. It can be configured in various ways.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a reactor water supply facility according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional reactor water supply facility.

3 is a schematic configuration diagram of a boiling water reactor plant to which the reactor water supply system of FIG. 1 is applied.

FIG. 4 is an explanatory diagram showing a state of reactor water supply equipment at the time of a pump trip accident in the configuration of FIG. 1.

FIG. 5 is a configuration diagram of a reactor water supply facility according to a second embodiment of the present invention.

FIG. 6 is a block diagram of a control system applied to the reactor water supply system of FIG.

FIG. 7 is a configuration diagram of a reactor water supply facility according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a reactor water supply facility according to a fourth embodiment of the present invention.

[Explanation of symbols]

1-4, 11-14, 31-35 ... Water supply pump, 5, 6
... Steam turbine, 7, 8, 15-18, 36-40 ... Electric motor, 9, 10, 23-25, 44, 45 ... Speed increaser, 1
9-22, 41-43 ... Fluid coupling, 26, 27 ... Thyristor, 51 ... Reactor, 52 ... High pressure turbine, 53 ... Moisture separation heater, 54 ... Low pressure turbine, 55 ... Condenser, 56
... Condensate pump, 57 ... Low-pressure feed water heater, 58 ... High-pressure feed water heater, 59 ... Water supply pipe, 60 ... Main steam pipe, 61 to 6
8, 81-88, 91-100 ... Gate valve, 69, 70,
89, 90, 101, 102 ... Water supply adjusting valve, 71 to 7
4, 76 ... Flowmeter, 75 ... Water level gauge, 77 ... Water supply control system.

Claims (7)

[Claims] 1. A reactor water supply facility comprising one standby system including a water supply pump and a water supply flow rate adjusting valve, and at least three service systems including a water supply pump installed in parallel in a reactor water supply path, comprising: Each of the water supply pumps is a water supply pump driven by an electric motor and has a substantially equal capacity to each other. At least two systems of the regular system include pump rotation speed varying means for controlling the rotation speed of the water supply pump. Reactor water supply facility characterized by being equipped. 2. A water supply control means for performing the adjustment of the rotation speed of the water supply pump of the normal system preferentially to the opening control of the water supply flow rate adjusting valve of the standby system in the range of the normal operation state. 1 reactor water supply equipment. 3. The reactor water supply facility according to claim 1, wherein the pump rotation speed varying means is means for controlling the rotation speed of the electric motor. 4. The reactor water supply facility according to claim 3, wherein the rotation speed control means is a thyristor. 5. The pump rotational speed varying means is a means that is provided between the electric motor and the water feed pump and that controls the rotational speed transmitted from the electric motor to the water feed pump. Reactor water supply facility. 6. The reactor water supply facility according to claim 5, wherein the rotation speed control means is a fluid coupling. 7. The reactor water supply equipment according to claim 1, wherein the water supply pump of the standby system is a water supply pump driven by the electric motor at a constant rotation speed.