JPH02214466A - Electromagnetic pump - Google Patents

Abstract

PURPOSE:To simplify an atomic reactor cooling system by providing an outer duct enclosing an inner duct having an inner core, an outer core having an electromagnetic coil provided on its outer periphery, and an eddy current type electromagnetic current meter provided in the inlet or outlet of the outer duct. CONSTITUTION:An outer core 11 and an electromagnetic coil 12 are disposed on the outer periphery of an outer duct 10, an inner duct 14 containing an inner core 13 is disposed at a position axially opposite to the core 11 inside the duct 10, and an annular liquid metal passage is formed to the duct 10. An eddy current type electromagnetic current meter 15 is disposed at the center of the passage at a predetermined distance from the core 11 and the coil 12. Since it is rectified by the duct 10, the flow rate can be measured by measuring the flowing velocity at the center of the duct 14 to simplify the system configuration, thereby increasing the degree of freedoms of designing the disposition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electromagnetic pump suitable for transporting and circulating coolant in a liquid metal cooled fast breeder reactor that uses liquid metal as a coolant.

(Prior art) In fast breeder reactors that use liquid metals such as sodium as coolants, the reactor coolant, that is, the sub-coolant, has a high level of radioactivity, so the sub-cooling system is isolated from the steam generation system. be done.

On the other hand, heat exchange equipment between liquid metal and water is essential to generate the steam that drives the turbine generator.

The primary coolant, such as sodium, tends to combine violently with air or water, and the heat of the chemical reaction is large.

Therefore, in order to prevent the effects of the reaction between water and liquid metal from spreading to the core even if the steam side piping of the steam generator is damaged, a secondary cooling system is added between the secondary cooling system and the steam generation system. is installed.

A cooling system in a conventional liquid metal cooled nuclear reactor will be explained with reference to FIG.

A reactor core 2 loaded with fuel assemblies is disposed at the center of a reactor vessel 1, and a coolant 3 such as a liquid metal such as sodium flows to cool the reactor core 2. The coolant 3 is circulated by a primary main circulation bomb 4 installed inside the reactor vessel 1 . -The secondary cooling system is a system consisting of a primary coolant 3 that cools the core 2, a primary circulation pump 4, and an intermediate heat exchanger 5 that exchanges heat between the secondary coolant and the secondary coolant. On the other hand, the secondary cooling system includes an intermediate heat exchanger 5, a steam generator 6 that generates steam to be supplied to a turbine generator (not shown),
It is comprised of a vertical liquid surface mechanical secondary main circulation pump 7 for circulating secondary coolant, and first to third piping 8a, 8b, 8c connecting these devices.

Further, an electromagnetic flowmeter 9 for measuring the circulating flow rate of the secondary coolant is disposed in the pipe 8C connecting the outlet of the secondary main circulation pump 7 and the intermediate heat exchanger 5.

(Problems to be Solved by the Invention) According to the conventional arrangement of the secondary cooling system, the secondary main circulation pump 7 and the steam generator 6 are installed separately, and their equipment and piping are located in the reactor auxiliary building. occupies a large proportion of the space,
There was an uneconomical need to increase the size of the building and ancillary equipment such as drain tanks.

In addition, since the connections of the piping 8a, 8b, and 8c that connect the steam generator 6 and the secondary main circulation pump 7, etc. are all fixed anchor points, the piping that connects each device absorbs thermal expansion. do. Therefore, it is necessary to form a pipe loop or meander in the middle of the pipe, which has the disadvantage that the length of the pipe becomes long, the space occupied by the pipe becomes large, and the size of the incidental equipment increases.

In response, the secondary main circulation pump will be changed from a mechanical pump to an electromagnetic pump. In addition, solutions have been proposed such as adopting an integrated steam generator with an electromagnetic pump built into the steam generator, but this requires a separate installation of an electromagnetic flowmeter to measure the flow rate. Due to restrictions in piping planning associated with the installation of this flowmeter (securing installation space, securing a straight pipe section of an appropriate length, etc.), this has not been a sufficient solution.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnetic pump capable of measuring flow rate in order to simplify the system and arrangement of a nuclear reactor cooling system.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes an inner duct having an inner core, an outer duct surrounding the inner duct, an outer core having an electromagnetic coil provided on the outer periphery of the outer duct, and the outer core. It is characterized by comprising an eddy current type electromagnetic current meter provided at the inlet or outlet of the duct.

(Function) In the electromagnetic pump of the present invention, the liquid metal flowing inside the electromagnetic pump is rectified by the inner duct and outer duct of the electromagnetic pump, so the flow velocity distribution is stable. By measuring the flow velocity with an eddy current electromagnetic current meter, it can be easily converted to a flow rate.

Furthermore, since the eddy current type electromagnetic current meter can be formed extremely compactly, the electromagnetic pump does not become larger by providing the current meter.

Therefore, restrictions on piping planning associated with the installation of an electromagnetic current meter are eliminated, the degree of freedom in designing the arrangement of equipment and piping is increased, and the total length of piping is also shortened.

(Example) An example of an electromagnetic pump according to the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 10 indicates an outer duct,
This outer duct 10 forms part of the liquid metal piping. An outer core 11 and an electromagnetic coil 12 are disposed around the outer periphery of the outer duct 10 so as to surround the outer duct 10. On the other hand, an inner duct 14 having a built-in inner core 13 is disposed inside the outer duct 10 at a position facing the outer core 11 in the axial direction. is formed. Further, an eddy current type electromagnetic current meter 1 is installed at one end of the inner duct 14 at a certain distance so as not to be affected by the magnetic field generated by the above-mentioned external iron core 11 and electromagnetic coil 12.
5 is arranged in the center of the liquid metal channel. Inside this eddy current type electromagnetic current meter 15, three sets of coils (not shown) are arranged in the axial direction electrically independent of each other.

In general, unlike electromagnetic flowmeters due to their structure, eddy current electromagnetic current meters are instruments that detect the local flow velocity of fluid near the outer surface of the current meter, making it difficult to measure the flow rate of the entire system. It is. However, in the electromagnetic pump of the present invention, the flow velocity distribution of the liquid metal flowing in the outer duct 10 is stable and rectified by the duct 10, so that by measuring the flow velocity in the center of the duct 14, It can be easily converted to flow rate. Furthermore, the flow rate of the entire system can be determined by measuring the flow rate at the inlet or outlet of the pump.

In addition, in the description of this example, for ease of explanation,
Although a straight pipe type electromagnetic pump is shown as an example, the same effect as described above can be obtained when an eddy current type electromagnetic current meter is provided in a center return type electromagnetic pump.

Next, as an example of application of the electromagnetic pump of the present invention, the electromagnetic pump of the present invention is incorporated into a steam generator with a built-in pump of a liquid metal cooled nuclear reactor, and the primary main circulation pump of a liquid metal cooled nuclear reactor. The case where the electromagnetic pump of the present invention is used will be explained using the drawings.

FIG. 2 is a schematic cross-sectional view of a steam generator with built-in pump incorporating the electromagnetic pump according to the present invention, and FIG. 3 is a liquid metal cooling type steam generator incorporating the electromagnetic pump according to the present invention into the primary main circulation pump. FIG. 2 is a schematic cross-sectional view of a nuclear reactor system.

In FIG. 2, the high-temperature liquid metal that has undergone heat exchange with the reactor-subsystem coolant (not shown) in the intermediate heat exchanger (not shown) passes through the steam generator inlet pipe 16 to the steam generator 17.
After flowing into the interior and exchanging heat with the water/steam system via the heat transfer tube 18, it returns to the intermediate heat exchanger (not shown) via the steam generator outlet piping 19. On the other hand, water, which is a water/steam-based coolant, is pumped by a water supply pump (not shown), supplied into the heat transfer tube 18 from the water inlet water chamber 20, and heated by heat exchange with liquid metal within the heat transfer tube 18. It becomes steam and is sent to a steam turbine (not shown) through the outlet steam chamber 21. Here, the liquid metal that is the secondary coolant is supplied to the steam generator 17.
The circulation is driven and the flow rate is controlled by an electromagnetic pump 22 according to the present invention disposed above the steam generator outlet piping 19 inside. Therefore, when the electromagnetic pump according to the present invention is used in a steam generator with a built-in pump, the main equipment that constitutes the secondary system is an intermediate heat exchanger, a steam generator, and two hot legs and cold legs that connect both equipment. Only piping is required, which simplifies the secondary system configuration and increases the degree of freedom in layout design.

Enables reduction of building volume, etc. of the entire plant. Furthermore, since the inlet or outlet flow rate of the pump can be measured in real time, the operation controllability of the secondary system is improved, which can contribute to improving the reliability of the entire plant.

FIG. 3 shows an example in which the electromagnetic pump according to the present invention is used as a primary main circulation pump of a tank type furnace.

In the figure, the liquid metal that is the reactor coolant absorbs heat generated in the reactor core 2 and becomes high temperature, and after being cooled by exchanging heat with the secondary coolant in the intermediate heat exchanger 5, it is returned to the reactor core 2. and goes back. This reactor coolant is circulated by a primary main circulation pump installed within the reactor vessel 1. In this type of reactor, the local flow rate is measured by a core outlet current meter (not shown) installed at the bottom of the upper core mechanism 23 installed above the reactor core 2. It is difficult to determine the overall coolant flow rate.

On the other hand, if the electromagnetic pump according to the present invention is used as a primary main circulation pump, the flow rate of the coolant at the pump outlet, that is, the circulation flow rate of the entire reactor coolant can be grasped, and it can be used in conjunction with the core outlet current meter described above. This makes it possible to grasp the overall flow rate and local flow rate at the same time. As a result, more fine-grained nuclear reactor operation control becomes possible. It can contribute to improving the reliability of the entire plant.

〔Effect of the invention〕

According to the present invention, the system configuration can be simplified and the degree of freedom in layout design can be increased. Furthermore, as a result, it becomes possible to reduce the length of piping, coolant inventory, building volume, etc., which has a significant effect on reducing the construction costs of nuclear power plants. Furthermore, since the operational controllability of the nuclear reactor is improved, it can greatly contribute to improving the reliability of nuclear power plants.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of an electromagnetic pump according to the present invention, and FIG. 2 is a schematic cross-sectional view of a steam generator with a built-in pump incorporating the electromagnetic pump according to the present invention. 3
The figure is a schematic cross-sectional view of a secondary system of a liquid metal cooled nuclear reactor using an electromagnetic pump according to the present invention as a primary main circulation pump.
FIG. 4 is a schematic system diagram showing the system configuration of a cooling system of a conventional liquid metal cooled nuclear reactor. 10...Outer duct 11...Outer core 12.
・Electromagnetic coil 13...Inner core 14...Inner duct 15...Eddy current type electromagnetic current meter Agent Patent attorney Yoshiaki Inomata (and one other person) ＃入”te=fu′ Tea

Claims (1)

[Claims] An inner duct having an inner core, an outer duct surrounding the inner duct, an outer core having an electromagnetic coil provided on the outer periphery of the outer duct, and an eddy current type provided at the inlet or outlet of the outer duct. An electromagnetic pump characterized by being equipped with an electromagnetic current meter.