JPH0729361Y2 - Steam generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a steam generator, and more particularly to a steam generator used in a secondary cooling device of a liquid metal cooled fast breeder reactor. .

(Prior Art) A conventional liquid metal cooling type fast breeder reactor cooling device will be described with reference to FIG. That is, in FIG. 3, reference numeral 1 indicates a reactor vessel of a fast breeder reactor, in which a reactor core 2, a liquid metal sodium coolant (hereinafter referred to as a liquid) 3, a primary main circulation pump are provided. 4 and an intermediate heat exchanger 5 are housed. The primary cooling system is composed of the liquid 3, the primary main circulation pump 4 and the intermediate heat exchanger 5. The secondary cooling system of the nuclear reactor penetrates the reactor building wall 7 to connect the intermediate heat exchanger 5, the steam generator 6 provided outside the reactor vessel 1, and the devices of both. The hot leg pipe 8 and the cold leg pipe 9 are arranged.

A liquid inlet pipe 11 is provided above the body barrel 10 of the steam generator 6, while a metal riser pipe 12 having an opening at the bottom of the body barrel 10 is arranged along the central axis of the body barrel 10. The liquid outlet pipe 13 is connected to the upper end of the rising pipe 12. In addition, a space above the liquid surface around the upper part of the rising pipe 12
An electromagnetic pump 15 is arranged at 14.

FIG. 4 shows a steam generator 6 installed in the secondary cooling system of the reactor.
FIG. 3 is a vertical cross-sectional view showing a detailed structure of the left half side surface. That is, in the steam generator 6, the main body 10 is supported by the pedestal 16 via the legs 17 and the support skirt 18. Further, the ascending pipe 12 is arranged in the center of the main body 10, a heat transfer pipe shroud 19 is arranged outside the rising pipe 12, and a large number of heat transfer pipes 20 are arranged in an annular space outside thereof. ing.

By the way, a free liquid surface 21 of the liquid is formed inside the upper part of the main body 10, and the space portion 14 above the free liquid surface 21 absorbs the volume change due to the thermal expansion of the liquid.

On the other hand, in the lower part of the main body 10, the water inlet pipe 22 into which the water supplied from the water supply pump flows, the header 23, the distribution pipe 24 and the water chamber 25, and the inlet portion of the water supply is as shown in FIG. Is composed of. Further, on the upper part of the main body 10, an outlet steam chamber 26, an outlet steam distribution pipe 27, an outlet steam header 28, and an outlet steam pipe 29.
And form the steam outlet.

FIG. 5 is a top view of the steam generator 6 in FIG.
That is, the inlet pipe 11 is branched into two lines and provided at the upper part of the main body cylinder 10, while the outlet pipe 13 is led out from the center of the top of the main body cylinder 10.

FIG. 6 is a vertical cross-sectional view showing the inside of the top of the steam generator 6 shown in FIG.
15 are provided. In this electromagnetic pump 15, a first electromagnetic coil group 33 and a second electromagnetic coil group 34 are wound inside and outside an annular flow path 32 formed in an annular shape between an inner core 30 and an outer core 31. It is composed of a stator coil system,
A magnetic field is generated by an electric current from an external power source to circulate the liquid.

The ascending pipe 12 containing the electromagnetic pump 15 is connected to the outlet pipe 13, and the outlet pipe 13 is connected to the cold leg pipe 9.

The cooling device configured as described above operates as follows.

By circulating the primary coolant 3 for cooling the heat generated in the core 2 by the primary main circulation pump 4, the heat is transferred to the secondary cooling system via the intermediate heat exchanger 5. On the other hand, the liquid of the secondary coolant is circulated by the electromagnetic pump 15 built in the steam generator 6, and the high temperature liquid metal that has absorbed the heat in the intermediate heat exchanger 5 passes through the hot leg pipe 8 and the inlet pipe 11 to the steam. It flows into the generator 6.

Then, the high temperature liquid gives heat so as to turn the feed water into steam while flowing down the outside of the heat transfer tube 20, and the liquid itself cools to become a low temperature liquid. This low-temperature liquid rises in the riser pipe 12 that is opened and connected at the lower part of the steam generator 6, and after the discharge pressure is applied by the electromagnetic pump 15, it passes through the outlet pipe 13 and the cold leg pipe 9. It is returned to the intermediate heat exchanger 5.

On the other hand, on the water / steam side, the water supplied from a water supply pump (not shown) flows into the header 23 from the water inlet pipe 22, is distributed in the distribution pipe 24, and is then divided into a plurality of water to the water chamber 25. Reach The supply water distributed from the water chamber 25 into the heat transfer pipe 20 is heat-exchanged with the liquid while rising in the heat transfer pipe 20 to rise in temperature and become steam, and then reaches the outlet steam chamber 26. Then, after passing through the outlet steam distribution pipe 27 and joining at the outlet steam header 28, it flows out from the outlet steam pipe 29 and is sent to a steam turbine (not shown).

(Problems to be Solved by the Invention) According to the above-described conventional cooling device, the electromagnetic pump 15 in the steam generator 6 is incorporated while being surrounded by the gas in the space portion 14 of the liquid free liquid surface 21. . Therefore, the coil group of the electromagnetic pump 15
The heat generated from 33 and 34 could not be efficiently dissipated by the gas whose heat transfer coefficient is lower than that of liquid.

Further, the heat conducted to the space portion 14 hardly radiates from the liquid free liquid surface 21 into the liquid, and most of the heat is radiated from the upper portion of the casing of the low-temperature steam generator 6 to the atmosphere, and the electromagnetic coil group 33, There was a problem that the heat generated in 34 was not used effectively.

The present invention was devised to solve the above problems, and efficiently removes heat generated from the electromagnetic coil group of an electromagnetic pump and recovers it in a liquid to minimize energy loss. An object of the present invention is to provide a steam generator for use in a cooling device for a liquid metal cooled nuclear reactor capable of producing the same.

[Constitution of device]

(Means for Solving Problems) In the present invention, a liquid inlet pipe is provided in an upper portion of a main body cylinder, and a liquid rising pipe having an opening in a lower portion of the main body cylinder is provided along an axial direction in the main body cylinder. A liquid outlet pipe is connected to an upper end of the rising pipe, a free liquid surface of the liquid is provided around an upper portion of the rising pipe, and an electromagnetic pump is provided in a space portion formed on the free liquid surface around the rising pipe. In the steam generator, the electromagnetic pump includes an inner core, a first electromagnetic coil group embedded in the inner core, and a second electromagnetic coil group facing the first electromagnetic coil group. Is embedded in the outer core, an annular flow path formed between the outer core and the inner core, and is formed along the axial direction of the outer core outer peripheral surface, and in the suction port of the annular flow path. An outlet and an inlet at the outlet of the annular flow path. It is characterized in that it is composed of a plurality of bypass flow paths communicating with each other.

(Operation) In the present invention, the heated liquid is supplied to the steam generator through the liquid inlet pipe, and heat is exchanged with the feed water to generate steam while descending the steam generator. The liquid whose temperature has dropped due to heat exchange is sucked up and returned from the lower end opening of the liquid rising pipe by the action of the electromagnetic pump. The electromagnetic pump arranged in the space above the liquid surface around the upper part of the rising pipe,
A moving magnetic field that moves the liquid in the direction of the liquid outlet pipe is formed.

Further, the space above the free liquid surface of the liquid in the steam generator serves to absorb the volume expansion and contraction of the inventory in the secondary cooling system due to the temperature change of the liquid.

In addition, the bypass flow path provided on the outer peripheral portion of the outer iron core that connects the discharge port and the suction port of the electromagnetic pump circulates the liquid from the discharge port side to the suction port side, and efficiently generates heat from the coil in the liquid To collect.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

1 and 2 are enlarged views of the electromagnetic pump 35 in the steam generator according to the present invention, and other parts are omitted because they are similar to the steam generator shown in FIGS. 4 to 6. . Therefore, in FIGS. 1 and 2, the same parts as those in the conventional example shown in FIGS. 5 to 6 are designated by the same reference numerals, and the description of the overlapping parts will be omitted.

Inner iron core 30 of electromagnetic pump 35 in FIGS. 1 and 2.
The first electromagnetic coil group 33 is embedded in the outer surface of the and is covered with a covering material 36. A through hole 37 is formed in the inner core 30, and argon gas is filled in the both-end coating material 38 projecting from both ends of the inner core 30 and the through hole 37.

On the other hand, both sides of the outer iron core 31 are also covered with the covering material 39,
An annular member 40 is provided on the outer periphery of the covering material 39 of the outer iron core 31,
A plurality of bypass flow paths 41 are formed in the annular member 40 along the axial direction of the outer peripheral surface of the outer iron core 31. A covering material 42 is also provided on the outside of the annular member 40.

Then, the inner core 30, the outer core 31, and the electromagnetic coil group
The electromagnetic pump 35 is constituted by 33 and 34.

The liquid to which the discharge pressure is given by the electromagnetic force of the electromagnetic coil groups 33, 34 is sucked from the suction port 43, is sent to the liquid outlet pipe 13 from the discharge port 44 through the annular flow path 32.

Further, the discharge port 44 is provided with the bypass flow channel inlet 45 of the bypass flow channel 41, and the suction port 43 is provided with the bypass flow channel outlet 46.

The inner surface of the outer core 31 and the inner core 30 are supported by
The annular flow path 32 is formed by being supported by 47. The annular member 40 is attached to the flange 48, and the flange 48 is welded to the flange of the steam generator 6 and the outlet pipe 13.

Next, the operation of the above embodiment will be described.

Due to the magnetic force generated by the electromagnetic coil groups 33, 34, the liquid flowing in the annular flow path 32 receives the discharge pressure and is discharged from the discharge port 44 into the outlet pipe 13 as in the conventional electromagnetic pump. At this time, comparing the liquid pressures, the pressure at the discharge port 44 is obviously higher at the suction port 43 and the discharge port 44.

Therefore, the liquid flows from the bypass flow passage inlet 45 to the bypass flow passage 41 and the bypass flow passage outlet 46, and again the annular flow passage 32.
The liquid circulates around the outer iron core 31 by a route of passing through to the bypass flow path inlet 45.

As a result, the heat generated from the second electromagnetic coil group 34 is more efficiently recovered in the liquid than when surrounded by the space 14, and the energy loss of the entire steam generator can be reduced.

[Effect of device]

According to the present invention, the heat generated from the electromagnetic coil, which has conventionally been dissipated from the gas space around the electromagnetic pump into the atmosphere, can be recovered by circulating the liquid in the bypass passage in the electromagnetic pump.

Thereby, the heat generated in the outer electromagnetic coil is efficiently cooled by the liquid, the temperature rise of the electromagnetic coil is suppressed, and the reliability of the electromagnetic coil can be improved. Further, by recovering the thermal energy released to the atmosphere, energy loss can be suppressed, and a highly reliable liquid metal cooling device as a whole can be obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an essential part of an embodiment of a steam generator according to the present invention, and FIG. 2 is a transverse sectional view showing an enlarged view by cutting along a line II-II in FIG. 3 to 6
The figure is for explaining the conventional example. Fig. 3 is a system diagram showing a connection relationship with a steam generator used for a cooling device of a fast breeder reactor, and Fig. 4 is a left half side view of the steam generator. 5 is a vertical cross-sectional view, FIG. 5 is a top view of FIG. 4, and FIG. 6 is an enlarged vertical cross-sectional view of the electromagnetic pump of FIG. 4 and its surroundings. DESCRIPTION OF SYMBOLS 1 ... Reactor vessel, 2 ... Core, 3 ... Coolant, 4 ... Primary circulation pump, 5 ... Intermediate heat exchanger, 6 ... Steam generator, 7 ... Reactor building wall, 8 ... Hot leg piping, 9 ... Cold leg piping , 10 ... Main body, 11 ... Inlet pipe, 12 ... Ascending pipe, 13 ... Outlet pipe, 14 ... Space part, 15 ... Electromagnetic pump, 16 ... Stand, 17 ...
Leg, 18 ... Support skirt, 19 ... Heat transfer tube shroud, 20 ... Heat transfer tube, 21 ... Free liquid level, 22 ... Water inlet piping, 23 ... Header, 24
… Distribution pipe, 25… water chamber, 26… outlet steam chamber, 27… outlet steam distribution pipe, 28… outlet steam header, 29… outlet steam pipe, 30… inner core, 31… outer core, 32… annular flow path, 33 ... 1st electromagnetic coil group, 34 ... 2nd electromagnetic coil group, 35 ... Electromagnetic pump,
36 ... Coating material, 37 ... Through hole, 38 ... Inside coating material on both ends, 39 ... Coating material, 40 ... Annular member, 41 ... Bypass channel, 42 ... Coating material, 43
… Suction port, 44… Discharge port, 45… Bypass channel inlet, 46… Bypass channel outlet, 47… Support, 48… Flange.

Claims (3)

[Scope of utility model registration request] 1. A liquid inlet pipe is provided on the upper part of the main body,
A liquid rising pipe having an opening in the lower part of the body barrel is provided along the axial direction in the body barrel, a liquid outlet pipe is connected to the upper end of the rising pipe, and a free liquid surface of liquid around the upper part of the rising pipe. A steam generator having an electromagnetic pump incorporated in a space formed around the rising pipe on the free liquid surface, the electromagnetic pump being embedded in the inner core and the inner core. A first electromagnetic coil group, an outer iron core in which a second electromagnetic coil group that opposes the first electromagnetic coil group is embedded, and an annular flow path formed between the outer iron core and the inner iron core A plurality of bypass flow passages that are formed along the axial direction of the outer peripheral surface of the outer core, and that have an outlet at the suction inlet of the annular flow passage and an inlet at the discharge outlet of the annular flow passage. A steam generator characterized in that. 2. The steam generator according to claim 1, wherein the surfaces of the inner core and the outer core that come into contact with the liquid are coated with a corrosion-resistant coating material. 3. The steam generator according to claim 1, wherein the liquid is sodium liquid metal.