JPH08211183A - Reactor recirculation driving system of boiling water reactor - Google Patents

Abstract

PURPOSE: To suppress the occurrence of trouble peculiar to large rotary machines and simplify maintenance works by installing a flow control valve for controlling discharge flow in the discharge side pipe of steam injector provided as driving device for reactor recirculation driving system. CONSTITUTION: A steam injector 29 is provided with an extraction steam piping 30, a driven water piping 31, discharge piping 32 and a drain piping, and the discharge piping 32 is provided with a flow control valve 36. In the case where a plurality of steam injectors 29 are provided, total discharge flow is controlled by operating the openings of the flow control valves 36 individually or in group with a split range method. In this manner, only one or a group of steam injectors 29 remains in the middle of full open and full close of the flow control valve 36, total drain flow from steam injectors 29 is minimized and the rest of the steam injectors 29 can be maintained in optimum range of operation state without drain flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor recirculation drive system for a boiling water reactor, and more particularly to a reactor recirculation system for a boiling water reactor using a steam injector as a drive pump for driving a jet pump. Regarding drive system.

[0002]

2. Description of the Related Art Boiling water reactor (hereinafter referred to as BWR)
As shown in FIG. 11, the coolant driven by the jet pump 2 in the reactor pressure vessel 1 is supplied to the core 3 as recirculation water, and a part of the recirculation water is steamed by heating in the core 3. This is separated by the separator 4 and is made to flow out as saturated steam from the main steam pipe 5 to the turbine 6 side to be used as power generation steam.

In a normal output operation state, the inside of the reactor pressure vessel 1 is maintained at a high pressure exceeding 7 MPa. The main steam pipe 5 from the outlet of the pressure vessel 1 to the turbine 6 is usually composed of four outlets of the pressure vessel 1 and is connected to the high pressure turbine 6a. In each of the four main steam pipes, a main steam relief safety valve 7 from the side of the reactor pressure vessel 1, two main steam isolation valves 9 sandwiching the wall 8 of the reactor containment vessel, and a turbine immediately before the high pressure turbine 6a on the downstream side. A steam control valve 10 is installed.

On the other hand, to the reactor pressure vessel 1, cooling water having a relatively low temperature, which is the same as the flow rate of steam flowing out, is supplied as water supply through a water supply sparger 11. The feed water is pressurized from the condenser 12 by the low pressure condensate pump 13, the high pressure condensate pump 14, and the feed water pump 15, heated by the feed water heater 16, and returned to the reactor pressure vessel 1.

The recirculated water that circulates in the reactor pressure vessel 1 and cools the core 3 flows out from the core 3 and then flows into the separator 4
After separating the evaporation in the inside, it flows out again into the bulk water 17 from the separator 4 in a saturated state, and after mixing with the feed water sparger water, the liquid temperature becomes lower than the saturation temperature (hereinafter referred to as subcooled water) downcomer. The part 18 descends and flows into the suction part of the jet pump 2.

The jet pump suction flow is accelerated by high-speed driving water discharged from the jet pump nozzle, and the dynamic pressure is converted into static pressure by the jet pump diffuser portion to increase the pressure, which is used as the driving pressure for recirculating water. It is discharged to the lower plenum 19 and flows into the core 3 again. The downcomer part 1
A part of the water descending 8 flows into the recirculation drive system 20, which is an external recirculation system, and is pressurized by the recirculation pump 21,
The jet pump driving water is jetted into the jet pump 2 from the jet pump nozzle. Normally, two systems of the external recirculation system 20 are provided, and the discharge side piping 22 of each system is branched and connected to the plurality of jet pumps 2.

In the suction portion of the jet pump 2, the flow path of water flowing from the downcomer portion 18 is suddenly narrowed, a frictional force acts between the wall of the jet pump suction portion and the coolant, and the high speed from the nozzle The shear pressure acts on the driving water ejected in step S3 to reduce the pressure and reduce the static pressure of the suction flow. At this time, when the suction flow temperature is close to the saturation temperature of the jet pump inlet, and when the flow velocity of the suction flow is large and the pressure reduction inside the suction part is large, the saturation temperature becomes lower than the suction flow temperature as the static pressure decreases. It may be further reduced, and an environment where cavitation is likely to occur may occur in the jet pump suction part. Further, since the nozzle flow is also jetted at a high speed, the pressure reduction is large, and when the liquid temperature is close to the saturation temperature, cavitation may occur. On the other hand, in the BWR plant, the flow velocity range is designed by design so that the suction flow temperature has a sufficient margin with respect to the saturation temperature and the suction flow and the nozzle flow do not have a large decompression. Cavitation does not occur during transient events.

In the BWR plant, since the steam voids generated in the core 3 and the reactor output have a negative feedback relationship through the increase / decrease in the neutron moderating capacity generated in the core 3, recirculation is performed near the rated operating point. It adopts a method to control the reactor power stably by adjusting the flow rate. The control of the recirculation flow rate is performed by operating the rotation speed of the induction generator of the recirculation pump 21 to change the power supply frequency of the recirculation pump motor and thereby adjusting the rotation speed of the recirculation pump 21. . The change in the number of revolutions of the recirculation pump 21 causes a change in the jet pump drive flow rate, that is, the flow rate of the nozzle flow to adjust the suction flow rate, and as a result, the jet pump discharge flow rate, that is, the recirculation flow rate in the reactor pressure vessel 1 is adjusted. It

[0009]

However, in the above-mentioned conventional BWR, since a plurality of recirculation pumps each driven by a large motor of about 6 MW are used as described above, the rotation speed control for these large motors is performed. It was not possible to ignore the possibility of various mechanical troubles associated with the above, and mechanical troubles due to the large load peculiar to large rotating machines such as motors and pumps. Therefore, there has been a concern that the mission of the nuclear power plant, which is the stable supply of electric power, may be hindered. Further, since the recirculation pump was installed inside the containment vessel, it required a great deal of effort for maintenance work such as periodic inspections, and at the same time, it had a problem of reducing the amount of radiation exposure of workers.

Therefore, an object of the present invention is to solve the problems of the conventional reactor recirculation drive system for a boiling water reactor, to significantly suppress the occurrence of troubles peculiar to large rotating machines, and to perform maintenance work. An object of the present invention is to provide a reactor recirculation drive system for a boiling water reactor, which can be simplified.

[0011]

In order to achieve the above object, the reactor recirculation drive system of a boiling water reactor according to claim 1 has a core and a jet pump composed of a plurality of groups. As a drive pump for driving the jet pump of the reactor pressure vessel to which the water supply system and the main steam system are connected, at least one steam injector is provided in parallel outside the reactor containment vessel for each group of the jet pumps. In a reactor recirculation drive system for a boiling water reactor, the jet pump is driven from a feed water pipe upstream of the feed water pump of the reactor feed water system to supply driven water to the jet pump. Water pipe, extraction steam pipe branched from the main steam pipe upstream of the main steam isolation valve of the main steam pipe to supply driving steam to the jet pump, and the driven water A flow rate control valve that controls the discharge flow rate of the steam injector by connecting a drain pipe that returns the drain flow of the steam injector to a water supply pipe or a condenser on the downstream side of the branch point of the pipe, and the discharge side pipe of the steam injector. It is characterized by having installed.

A reactor recirculation drive system for a boiling water reactor according to claim 2 of the present application has a core and a jet pump including a plurality of groups built-in, and a reactor water supply system and a main steam system are connected to the reactor. As a drive pump for driving the jet pump of the pressure vessel, at least one steam injector for each group of the jet pump is provided in parallel outside the reactor containment vessel in parallel to drive a reactor recirculation of a boiling water reactor. In the system, to the jet pump, driven water pipe branched from the water supply pipe upstream of the water supply pump of the reactor water supply system to supply driven water to the jet pump,
Extraction steam pipe for branching from the main steam pipe upstream of the main steam isolation valve of the main steam pipe to supply driving steam to the jet pump, and water supply pipe downstream of the branch point of the driven water pipe Alternatively, a drain pipe that returns the drain flow of the steam injector to the condenser is connected, and a flow control valve that controls the discharge flow rate of the steam injector by adjusting the flow rate of the steam for driving the steam injector is connected to the extraction steam pipe. It is characterized by being installed.

According to a third aspect of the present invention, there is provided a reactor recirculation system for a boiling water reactor including a reactor core, a jet pump having a plurality of groups, and a reactor water supply system and a main steam system connected to the reactor pressure. As a drive pump for driving the jet pump of the vessel, at least one steam injector for each group of the jet pump is provided in parallel outside the reactor containment vessel in parallel to the reactor recirculation drive system of the boiling water reactor. In the jet pump, a driven water pipe for supplying driven water to the jet pump, which is branched from a water supply pipe upstream of the water supply pump of the reactor water supply system, and a main steam isolation valve of the main steam pipe. Of the main steam pipe on the upstream side of the extraction steam pipe for supplying the driving steam to the jet pump, and the feed water pipe or the condensate water on the downstream side of the branch point of the driven water pipe. The drain pipe for returning the drain flow of the steam injector is connected to, the flow control valve is installed in both the discharge side pipe of the steam injector and the extraction steam pipe, and the steam injector is controlled by the discharge side flow control valve of the steam injector. Control the discharge flow rate of
The valve opening of the flow control valve of the extraction steam pipe is controlled based on the valve opening request signal.

The reactor recirculation system for a boiling water reactor according to claim 4 of the present application is the reactor recirculation system according to any one of claims 1 to 3, wherein a plurality of steam injectors are installed. The flow control valve is characterized in that the valve opening is controlled by the split range method.

A reactor recirculation system for a boiling water reactor according to claim 5 of the present application is the reactor recirculation system according to any one of claims 1 to 4, wherein the pressure drop of the discharge flow to the discharge part of the steam injector. It is characterized by having an orifice for use therein.

According to a sixth aspect of the present invention, there is provided a reactor recirculation system for a boiling water reactor according to any one of the first to fifth aspects, in which the driven water pipe is connected to the reactor water supply system. It is characterized in that it is branched from the water supply pipe on the downstream side of the water supply pump.

According to a seventh aspect of the present invention, there is provided a reactor recirculation system for a boiling water reactor according to any one of the first to fifth aspects, in which the driven water pipe of the steam injector is connected to a condenser. And the drain pipe is returned to the condenser or the water supply pipe immediately downstream of the condenser.

According to the eighth aspect of the present invention, there is provided the reactor recirculation system for a boiling water reactor according to any one of the first to fifth aspects, wherein the driven water pipe is connected to the reactor water supply system. It is characterized in that it is branched from the water supply pipe on the downstream side of the water supply pump, and the extraction steam pipe is branched from between the high pressure turbine and the low pressure turbine.

According to a ninth aspect of the present invention, there is provided a reactor recirculation system for a boiling water reactor according to any one of the first to eighth aspects, wherein at least a part of the steam injector is a double annular nozzle. It consists of a high-performance steam injector that ejects driven water and extracted steam with the high-performance steam injector discharge flow rate and drain flow rate by changing the insertion amount of the central steam nozzle and driven water nozzle into the steam injector. It is characterized by optimal control.

[0020]

The reactor recirculation system of the boiling water reactor according to any one of claims 1 to 9 of the present application can be operated from a drive device by using a steam injector as a device for driving the reactor recirculation drive system. By eliminating the rotating part such as a motor, the occurrence of mechanical trouble can be greatly suppressed.

Further, by disposing the main part of the recirculation drive system outside the storage container, it becomes possible to simplify the maintenance work and reduce the work amount.

Further, since the high pressure steam discharged from the reactor pressure vessel or the high pressure turbine is used as the drive source of the steam injector, the latent heat of the steam can be converted into the driving pressure, and the heat energy can be efficiently utilized. It becomes possible.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

First, the operating principle of the steam injector will be described with reference to FIG. The steam injector 29 ejects a supersonic flow of steam from the steam nozzle 23, condenses the ejected steam on the boundary surface with the driven water sucked from the mixing nozzle 24, and converts the thermal energy mainly composed of latent heat of vaporization into kinetic energy. It is converted to (momentum) and transmitted to the driven water. Condensation ends up to the main nozzle throat 25 and a high speed stream of water is obtained. This water flow is decelerated and boosted by the diffuser 26 to obtain a high discharge pressure equal to or higher than the vapor pressure flowing from the vapor nozzle 23.
When the steam injector is activated, the discharge check valve 27 is closed because the sampling discharge pressure is low, and drain water is caused to flow out from the overflow check valve 28. When the discharge pressure sufficiently increases, the discharge check valve 27 opens and the discharge water starts to flow. When the discharge pressure sufficiently increases, the overflow check valve 28 closes and the drain water stops flowing out. The discharged water and the drain flow are heated by the condensation of the steam.

Since the steam injector discharges water having a pressure several times higher than the steam pressure by this steam condensation, if high-pressure steam having a sufficiently high pressure is supplied to the steam nozzle 23, the discharge pressure will be compared with the reactor pressure vessel pressure. It can be used as a drive source when injecting cooling water into the reactor pressure vessel during output operation. The discharge pressure of the steam injector tends to decrease from the cutoff discharge pressure in proportion to the square of the flow rate as shown in the above equation, but the pressure loss coefficient may change due to turbulence in the steam injector flow path. In some cases, even if the discharge water amount and the drain flow rate are changed, the discharge pressure decrease tendency as described above may not always be exhibited. Generally, it is desirable for the discharge pressure to decrease with respect to the increase in the discharge flow rate in terms of flow rate control characteristics, so when utilizing the steam injector as a pump, the region in which the discharge pressure / discharge flow rate relationship is reversed is included in the operating range of the steam injector. Try not to.

Next, a first embodiment of the present invention will be described with reference to FIG.

The reactor pressure vessel 1 has a core 3 inside,
Reactor water is recycled by jet pump 2 as core 3
And a part of the recirculated water heated in the core 3 is supplied as steam to the main steam pipe 5 of the main steam system. The saturated steam that has flowed into the main steam pipe 5 passes through two main steam isolation valves 9 provided with the reactor containment vessel wall 8 in between, and a turbine steam control valve 10 downstream thereof, and a turbine 6 including a high-pressure turbine 6a. Is supplied to.

On the other hand, the reactor pressure vessel 1 is supplied with cooling water having a relatively low temperature, which is the same as the flow rate of steam flowing out, by a water supply system. The feed water is generated by the condenser 12, driven by the low pressure condensate pump 13 and the high pressure condensate pump 14, heated by the feed water heater 16 and then pressurized by the feed water pump 15, and the reactor pressure is supplied through the feed water sparger 11. Returned to container 1.

In order to drive the jet pump 2,
A reactor recirculation drive system is provided outside the reactor pressure vessel 1, preferably outside the reactor containment wall 8. This nuclear reactor recirculation drive system has at least one steam injector 29 for each jet pump 2 or each jet pump group, and supplies the high-pressure discharge water to the jet pump 2.

To each steam injector 29, an extraction steam pipe 30, a driven water pipe 31, a discharge pipe 32 and a drain pipe 33 are connected. The extraction steam pipe 30 is branched from the upstream side of the main steam isolation valve 9 of the main steam pipe 5, and supplies high-pressure drive steam to each steam injector 29. The driven water pipe 31 is branched from the water supply system pipe between the high-pressure condensate pump 14 and the water supply pump 15, and supplies driven water driven by the steam injector 29. Discharge pipe 32
Are connected to the respective jet pumps 2 so as to supply the water pressurized by the steam injector 29 as driving water. Further, the drain pipe 33 is connected so that the drain returned to water by the steam injector 29 is returned to the condenser 12.

The discharge pipe 32 has a discharge check valve 27,
An ON / OFF valve 34 is installed in the driven water pipe 31, an extraction check valve 35 is installed in the extraction steam pipe 30, and an overflow check valve 28 is installed in the drain pipe 33. Further, a flow rate control valve 36 is provided in the discharge pipe 32 of each steam injector 29. Further, the flow rate control valve 36
A feed water heater 16 is provided downstream of. In the figure, the driven water pipe ON / OFF valve 34 and the bleed check valve 3 are shown.
Although 5 is drawn collectively, a configuration in which these are provided in individual pipes connected to each steam injector 29 is also conceivable. Further, although the flow rate control valve 36 is provided in each steam injector 29 in the drawing, it may be provided in the discharge pipe 32 for each group of the steam injectors 29.

When the steam injectors 29 are arranged in parallel, the extraction steam pipe 30, the driven water pipe 31, and the discharge pipe 3 which are simply arranged in parallel and are connected to the respective steam injectors 29.
2. A structure in which the drain water pipes 33 are connected by the same header and a plurality of steam injectors 29 are bundled to form a plurality of groups, and extraction steam pipes 30, driven water pipes 31, discharge pipes 32, drains to these groups are formed. Any configuration is possible in which the water pipes 33 are connected by a plurality of headers and then each group is further bundled to form the whole.

When there are a plurality of steam injectors 29, the total discharge flow rate is controlled by operating the opening of the flow rate control valve 36 individually or in a group unit by the split range method. By manipulating the total discharge flow rate, that is, the jet pump driving water flow rate, the jet pump suction flow rate is changed, and the reactor recirculation flow rate can be adjusted. At this time, when a plurality of steam injectors 29 are installed by adopting the split range method, the steam injectors 29 with the opening degree of the discharge side flow rate control valve 36 between the fully closed and the fully opened are one or one group. It is possible to stay and minimize the total drain flow rate from the steam injector 29, while at the same time maintaining the operating state of the remaining steam injector 29 in an optimal range with no drain flow rate. By providing a pipe connected immediately downstream of the driven water branch point and connecting the drain water pipe 33 from the steam injector 29 to this, the drain flow heated by mixing with steam is supplied to the water supply system. Return to. As a result, it is possible to avoid heat loss on the heat balance of the plant. In some cases, the drain flow may have to be returned to the condenser 12 instead of the water supply system in consideration of the characteristics when the steam injector 29 is started and stopped. The return destination of the drain flow is switched by the drain pipe 33 and a valve on the connection pipe to the water supply system depending on the operating state of the steam injector 29. On the other hand, in order to prevent cavitation of the jet pump 2, it is desirable that the feed water heater 16 installed on the feed water pipe has a small capacity so as to avoid temperature rise of the feed water as much as possible. The capacity should not be much lower than the plant feed water temperature of about 210 ° C.

FIG. 3 shows a second embodiment of the present invention. In the extraction steam pipe 30 connecting the four main steam pipes 5 to each steam injector 29, one extraction steam pipe 30 is provided. After bundling, it is branched again in multiple stages up to the number of steam injectors. An extraction steam flow rate control valve 37 is installed in each of the branch pipes at the intermediate branching stage or the final branching stage on the extraction steam pipe, and the valve opening is adjusted by the split range system using the extraction steam flow control valve 37 to adjust each steam injector 2
Operate the extraction steam supply amount to 9. The steam injector discharge flow rate can be controlled by operating the extracted steam supply amount. According to this embodiment, the drain flow rate can be suppressed to a low level as compared with the case where the flow rate control valve 36 is installed in the steam injector discharge section of the first embodiment to control the discharge flow rate. By adopting the split range method, the number of steam injectors 29 whose supply steam flow rate is between zero and maximum with respect to the plurality of steam injectors 29 remains in one unit or one group, and the total drain flow rate can be minimized and at the same time. The operating state of the steam injector 29 can be maintained in an optimum range with no drain flow rate. At this time, since the extracted steam is a critical flow, considering that the flow rate is determined by the flow passage cross-sectional area of the extraction nozzle portion of the steam injector 29, when the specific extracted steam flow rate control valve 37 is opened / closed, the other fully opened state. Since the change in pressure at the position of the extracted steam flow control valve 37 is small, the amount of extracted steam of the steam injector 29 driven by this is almost unchanged and there is an advantage that no disturbance is applied.

FIG. 4 shows a third embodiment of the present invention, in which flow control valves 36 and 37 are installed on both the discharge side and the extraction steam pipe side of each steam injector 29,
The discharge flow rate control valve 36 on the discharge side is connected to the steam injector 29.
In the case of a plurality of gas flow rates, the split range method is used to control the valve opening to control the total discharge flow rate, while the extraction steam flow rate installed in the extraction steam pipe is based on the opening request signal of the discharge side flow rate control valve 36. It is characterized in that the opening degree of the control valve 37 is controlled. With such a configuration, optimum control of the discharge flow rate and the drain flow rate can be realized.

FIG. 5 shows a fourth embodiment of the present invention, which is characterized in that an orifice 38 is provided in each of the discharge parts of the steam injector 29. The steam injector 29 generally has a tendency to reduce the cutoff discharge pressure substantially in proportion to the square of the discharge flow rate, but the pressure loss coefficient changes depending on the turbulence of the internal flow, and the distribution of the discharge flow rate and the drain flow rate changes. In some cases, the discharge pressure may not always monotonically decrease with respect to the discharge flow rate. This is not desirable as a pump characteristic, as described above. Therefore, it is necessary to compensate for this at the downstream side of the steam injector discharge side and add a pressure loss element such that the amount of increase from the steam injector suction water pressure monotonously decreases with respect to the discharge flow rate as a whole. This is achieved by the orifice 38 in this embodiment.

FIG. 6 shows a fifth embodiment of the present invention, in which the driven water supply pipe 3 for the steam injector 29 is used.
1 is branched from the downstream side of the water supply pump 15 outlet header,
Further, a drain water pipe 33 for returning the drain flow from the steam injector 29 to the position immediately downstream of the driven water branch point and the condenser 12 is provided, and the switching ON / OFF valves 34 ′, 34 are provided on the drain water pipe 33. In this case, since the water supply pump 15 can be used as a booth pump for the steam for sucking in the steam injector, the steam injector 2
Since the boosting amount of 9 is about half that of the first to third embodiments, it is possible to downsize the steam injector 29 or reduce the number of parallel injectors, and at the same time, to increase the steam injector 2
9 Since the pump characteristics of a single unit can be afforded, a design margin in terms of shape and material is created, and both economical efficiency and reliability are improved.

FIG. 7 shows a sixth embodiment of the present invention, in which the driven water supply pipe 3 for the steam injector 29 is used.
1 from the condenser 12 and also the steam injector 2
A drain water pipe 33 for returning the drain flow from 9 to the condenser 12 or a position immediately downstream thereof is provided. in this case,
Since there is no pump having a movable part on the upstream side of the steam injector 29, accidents and failure factors in the jet pump drive system are reduced as compared with the other examples, system reliability is improved, and the water supply system is improved. Since there is no flow rate interference effect with, the reliability and controllability are improved from the viewpoint of flow rate control during transient of both systems.

FIG. 8 shows a seventh embodiment of the present invention, in which the driven water supply pipe 3 for the steam injector 29 is used.
1 is branched from the downstream side of the water supply pump 15 outlet header,
On the other hand, the extraction pipe 30 is branched from between the high-pressure turbine 6a and the low-pressure turbine 6b to supply the driving high-pressure steam to the steam injector 29, and the drain flow from the steam injector 29 is directly downstream of the driven water branch point. A drain water pipe 33 is provided for returning to the position or the condenser 12. By configuring the recirculation drive system in this way, it becomes possible to raise the driven water exceeding 7 MPa to a high pressure sufficient to drive the recirculation system by a drive vapor pressure of about 3 MPa.

FIG. 9 shows an eighth embodiment of the present invention, in which a part or all of the steam injector 29 is provided.
A high performance steam injector 39 for injecting driven water and extracted steam by a double annular nozzle is used. The high-performance steam injector 39 has already been proposed in, for example, Japanese Patent Application No. 3-227018, but its outline will be described below with reference to FIG.

In the high-performance steam injector 39, the central steam nozzle 40 and the driven nozzle 42 are concentrically arranged, and the outer peripheral steam nozzle 4 is provided outside the driven water nozzle 42.
1 is provided. High pressure steam is supplied to the central steam nozzle 40 through the central steam flow hole 44, and high pressure steam is also supplied to the outer peripheral steam nozzle 41. On the other hand, the driven water is supplied to the driven water nozzle 42 through the driven water inflow hole 43. Central steam nozzle 40 and peripheral steam nozzle 4
The driven water is accelerated by the thermal energy of the supersonic steam flow ejected from No. 1 and is decelerated and pressure-increased by the diffuser 26 to become high-pressure discharged water. Overflow hole 4 at startup
It is necessary to discharge the drain water through 5. In the high-performance steam injector 39, the central steam nozzle drive handle 46 is used to insert the central steam nozzle 40 into the driven water nozzle 42, or the driven water nozzle drive water handle 47 is used to rotate the outer peripheral steam. By changing the insertion amount of the driven water nozzle 42 in the nozzle 41, it is possible to operate the driven water flow rate, control the discharge water flow rate, and at the same time perform the optimum flow rate control in which the drain flow rate is minimized. .

The recirculation system drive pump shown in FIG. 9 is constructed by individually arranging the high-performance steam injector 39 and the other steam injector 29 in parallel, or by further arranging a group in which a plurality of steam injectors are arranged in parallel. . The extraction steam pipe 50 for high-performance steam injector connected to the high-performance steam injector 39 is branched from the extraction steam pipe 30 on the upstream side by the extraction steam flow rate control valve 37, and further for the outer peripheral steam nozzle immediately before the high-performance steam injector 39. The high-pressure steam is supplied to the high-performance steam injector 39 by branching into the extraction steam pipe and the extraction steam pipe for the central steam nozzle. The high-performance steam injector 39 is further provided with a central steam nozzle drive handle actuator 48 and a driven water nozzle drive handle actuator 49, which operate by adjusting the insertion amounts of the central steam nozzle 40 and the driven water nozzle 42, respectively. The performance steam injector 39 can be maintained in the optimum operating state. The optimum operation of the insertion amount of the central steam nozzle 40 and the driven water nozzle 42 via both actuators is performed by the already proposed multi-input 2-output control circuit 5
1 (Japanese Patent Application No. 3-227018). Further, similarly to the discharge flow rate adjusting valve 36 provided individually or in group units on the discharge side of the steam injector 29, control to the extraction steam flow rate adjusting valve 37 provided individually or in group units on the extraction steam line of the steam injector 29 is performed. The flow rate request signal to the flow rate control circuit 51 of the system and the high performance steam injector 39 is output by the split range method as in the other embodiments. With such a configuration, the drain flow rate of each steam injector is minimized, and then the optimal control of the discharge flow rate is realized.

[0043]

As described above, according to the present invention, a steam injector is used as a drive unit of a reactor recirculation drive system,
High-pressure steam of the main steam system is used as driving steam for the steam injector. As described above, by using the steam injector as the driving device, it is possible to eliminate the large-sized rotating part from the reactor recirculation drive system and significantly suppress the occurrence of troubles peculiar to the large-sized rotating machine. In addition, the equipment for a large AC power source for driving the motor, which has been required in the past, is also unnecessary.

Further, since the high pressure steam of the main steam system of the nuclear reactor is used to drive the steam injector, a part of the thermal energy generated in the nuclear reactor can be utilized in the nuclear reactor recirculation drive system, and high energy utilization is possible. Efficiency can be realized.

Further, by installing the steam injector, which is a main part of the reactor recirculation drive system, outside the reactor containment vessel, simplification of maintenance work, reduction of radiation exposure and reduction of work amount are realized. Therefore, the maintenance work environment and the plant operation rate can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a reactor recirculation drive system of a boiling water reactor according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration and an operating principle of a steam injector.

FIG. 3 is a diagram showing the configuration of a reactor recirculation drive system of a boiling water reactor according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a reactor recirculation drive system of a boiling water reactor according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a structure of a reactor recirculation drive system of a boiling water reactor according to a fourth embodiment of the present invention.

FIG. 6 is a diagram showing the configuration of a reactor recirculation drive system of a boiling water reactor according to a fifth embodiment of the present invention.

FIG. 7 is a diagram showing the configuration of a reactor recirculation drive system of a boiling water reactor according to a sixth embodiment of the present invention.

FIG. 8 is a diagram showing the configuration of a reactor recirculation drive system of a boiling water reactor according to a seventh embodiment of the present invention.

FIG. 9 is a diagram showing the configuration of a reactor recirculation drive system of a boiling water reactor according to an eighth embodiment of the present invention.

FIG. 10 is a diagram illustrating the configuration and operating principle of a high-performance steam injector.

FIG. 11 is a diagram showing a configuration of a reactor recirculation drive system of a conventional boiling water reactor.

[Explanation of symbols]

 1 Reactor Pressure Vessel 2 Jet Pump 3 Core 5 Main Steam Pipe 6a High Pressure Turbine 6b Low Pressure Turbine 8 Containment Vessel Wall 9 Main Steam Isolation Valve 12 Condenser 13 Low Pressure Condensate Pump 14 High Pressure Condensate Pump 15 Water Supply Pump 29 Steam Injector 30 Drain water pipe 31 Driven water pipe 32 Discharge pipe 33 Drain water pipe 34 ON / OFF valve 35 Extraction check valve 36 Discharge flow control valve 37 Extraction steam flow control valve 38 Orifice 39 High performance steam injector 40 Central steam nozzle 41 Peripheral steam Nozzle 42 Driven water nozzle 46 Central steam nozzle drive handle 47 Driven water nozzle drive handle 48 Central steam nozzle drive handle actuator 49 Driven water nozzle drive handle actuator 50 High-efficiency steam injector extraction steam piping 51 Actuator Control circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Nabayashi 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center

Claims (9)

[Claims] 1. Each group of the jet pumps as a drive pump for driving the jet pump of a reactor pressure vessel having a core and a jet pump including a plurality of groups and having a reactor water supply system and a main steam system connected thereto. In a reactor recirculation drive system of a boiling water reactor in which at least one steam injector is provided in parallel outside the reactor containment vessel, the jet pump is connected to the upstream side of the water supply pump of the reactor water supply system. Of the driven water pipe branched from the water supply pipe for supplying the driven water to the jet pump, and branched from the main steam pipe upstream of the main steam isolation valve of the main steam pipe for driving the jet pump. Extraction steam piping for supplying steam,
Connect a drain pipe that returns the drain flow of the steam injector to a water supply pipe or a condenser on the downstream side of the branch point of the driven water pipe, and control the discharge flow rate of the steam injector to the discharge side pipe of the steam injector. A reactor recirculation drive system of a boiling water reactor characterized by having a flow control valve installed. 2. Each group of the jet pumps as a drive pump for driving the jet pump of a reactor pressure vessel in which a core and a jet pump including a plurality of groups are built-in and to which a reactor water supply system and a main steam system are connected. In a reactor recirculation drive system of a boiling water reactor in which at least one steam injector is provided in parallel outside the reactor containment vessel, the jet pump is connected to the upstream side of the water supply pump of the reactor water supply system. Of the driven water pipe branched from the water supply pipe for supplying the driven water to the jet pump, and branched from the main steam pipe upstream of the main steam isolation valve of the main steam pipe for driving the jet pump. Extraction steam piping for supplying steam,
The drain pipe for returning the drain flow of the steam injector is connected to the water supply pipe or the condenser on the downstream side of the branch point of the driven water pipe, and the steam flow for driving the steam injector is adjusted to the extraction steam pipe. A reactor recirculation drive system for a boiling water reactor, characterized in that a flow control valve for controlling the discharge flow rate of the steam injector is installed. 3. A group of jet pumps as drive pumps for driving the jet pumps of a reactor pressure vessel having a core and a jet pump including a plurality of groups and having a reactor feed water system and a main steam system connected thereto. In a reactor recirculation drive system of a boiling water reactor in which at least one steam injector is provided in parallel outside the reactor containment vessel, the jet pump is connected to the upstream side of the water supply pump of the reactor water supply system. Of the driven water pipe branched from the water supply pipe for supplying the driven water to the jet pump, and branched from the main steam pipe upstream of the main steam isolation valve of the main steam pipe for driving the jet pump. Extraction steam piping for supplying steam,
Connect the drain pipe returning the drain flow of the steam injector to the water supply pipe or the condenser on the downstream side of the branch point of the driven water pipe, and the flow rate to both the discharge side pipe of the steam injector and the extraction steam pipe. A control valve is installed, the discharge flow rate control valve of the steam injector controls the discharge flow rate of the steam injector, and the valve opening degree of the flow rate control valve of the extraction steam piping is controlled based on the valve opening request signal. A reactor recirculation drive system for a boiling water reactor characterized by the above. 4. The steam injector according to claim 1, wherein a plurality of the steam injectors are installed, and the flow control valve has a valve opening controlled by a split range method. Recirculation drive system for boiling water reactor in Japan. 5. The re-reactor of a boiling water reactor according to claim 1, wherein an orifice for pressure drop of a discharge flow is installed in a discharge part of the steam injector. Circulation drive system. 6. The boiling water type according to claim 1, wherein the driven water pipe is branched from a water supply pipe downstream of a water supply pump of the reactor water supply system. Reactor recirculation drive system of the reactor. 7. The driven water pipe of the steam injector is branched from a condenser, and the drain pipe is returned to the condenser or a water supply pipe immediately downstream of the condenser. Item 5. A nuclear reactor recirculation drive system for a boiling water reactor according to any one of Items 5. 8. The driven water pipe is branched from a water supply pipe downstream of a water supply pump of the reactor water supply system, and the extraction steam pipe is branched from between a high pressure turbine and a low pressure turbine. A reactor recirculation drive system for a boiling water reactor according to any one of claims 1 to 5. 9. At least a part of the steam injector comprises a high-performance steam injector for ejecting driven water and extracted steam by a double annular nozzle, and the central steam nozzle and the driven water nozzle are inserted into the steam injector. 9. The high-performance steam injector discharge flow rate and the drain flow rate are optimally controlled by changing the amounts respectively, and the reactor recirculation drive of the boiling water reactor according to claim 1. system.