JP3095434B2 - Sodium-cooled fast breeder reactor plant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sodium-cooled fast breeder reactor plant.

[0002]

2. Description of the Related Art A sodium-cooled fast breeder reactor plant is
The energy extraction temperature is 500-700 ° C. on the other hand,
The most commonly used light water reactor cooled nuclear power plant has an energy extraction temperature of 200 to 400 ° C,
The sodium-cooled fast breeder reactor plant has a higher energy extraction temperature than the light water reactor-cooled nuclear power plant. As a result, the secondary system has a high energy conversion efficiency and is a promising nuclear power plant.

Next, a conventional example of this sodium-cooled fast breeder reactor plant will be described with reference to FIG. 7. Reference numeral 01 denotes a sodium-cooled fast breeder reactor, 02 denotes a fast breeder reactor, and 03 denotes a primary / secondary sodium / sodium heat. An exchanger, 04 is a steam generator, 06 is a feedwater pump, and the sodium-cooled fast breeder reactor 01 is composed of the above-mentioned devices 02 to 04, 06.

[0004] Further, reference numeral 11 denotes a steam turbine type power generator,
Is a high-pressure steam turbine (13 is a low-pressure steam turbine), 14
Is the high-pressure steam turbine 12 (and the low-pressure steam turbine 13)
Generator driven by a turbine, 16 is a condenser, 1
Reference numeral 7 denotes a condensing pump, reference numeral 18 denotes a cooling water pump, and the steam turbine type power generator 11 is constituted by the devices 12 to 18 described above.

In this sodium-cooled fast breeder reactor plant, nuclear energy is converted into heat energy of molten sodium at 500 to 700 ° C. That is, the low-temperature molten sodium is led to the fast breeder reactor 02, where it is heated to 500-700 by nuclear heat.
Heat to ℃ and raise the temperature to the primary / secondary sodium /
It is led to the sodium heat exchanger 03, where the secondary sodium is heated and heated, while the cooled primary sodium is led to the sodium / sodium heat exchanger 03 → pump (not shown), where the pressure is raised. Then, fast breeder reactor 0
Lead to 2.

Further, the secondary sodium heated and heated by the sodium / sodium heat exchanger 03 is led to a steam generator 04, where the feed water is heated to about 400 to 560 ° C. and heated to remove steam. This steam is generated, and the high-pressure steam turbine 12 of the steam turbine power generator 11 →
The steam turbine 12 is led to the low-pressure steam turbine 13
And 13 drive a turbine generator 14 to convert heat energy to electrical energy, then guide steam to a condenser 16 where it condenses, and then condensed water (feed water) to a condensate pump 17 , Where the pressure is increased, and the steam is again guided to the steam generator 04. On the other hand, heat is applied to the feed water by the steam generator 04, and the temperature of the lowered secondary sodium is led to a pump (not shown), where the pressure is increased, and the primary / secondary sodium / sodium heat exchanger is returned again. Lead to 03.

[0007]

In the conventional sodium-cooled fast breeder reactor plant shown in FIG. 7, since nuclear energy is converted into electric energy, it is directly affected by the load fluctuation at the demand end of electricity. Therefore, some of the sodium-cooled fast breeder reactor plants need to be shut down at night when demand is low.

[0010] Normally, the follow-up of the load fluctuation is performed by the steam flowing into the steam turbine, in other words, the temperature, pressure and flow rate of the secondary sodium to the steam generator 04, and the primary / secondary sodium / sodium. This can be handled by appropriately controlling the temperature, pressure, flow rate, and nuclear heat of the primary sodium into the heat exchanger 03. However, when the plant is shut down, a great deal of labor is required. Has to be reduced.

Further, as described above, it takes a great deal of effort to properly control the temperature, pressure, flow rate, and nuclear heat of sodium in each system, and it is necessary to plan to operate exclusively with a constant load. There is no problem. That is, pure sodium has a melting point of 98 ° C and a boiling point of 881 ° C (at 1 atm).
In order to prevent sodium coagulation even when the plant is stopped, it is necessary to keep the temperature of the sodium system at about 200 ° C. or higher. This is a factor that requires a lot of labor to start and stop unlike the light water reactor.

The present invention is proposed in view of the above-mentioned problems, and its object is to easily respond to fluctuations in power demand, to efficiently produce hydrogen, and to further reduce plant production costs. Another object of the present invention is to provide a sodium-cooled fast breeder reactor plant that can be used.

[0011]

In order to achieve the above object, a sodium-cooled fast breeder reactor plant according to the present invention comprises:
A steam turbine power generator driven by high pressure and high temperature steam sent from a heat exchanger provided in a steam system of a sodium-cooled fast breeder reactor, and an exhaust gas of the steam turbine power generator is reheated by the heat exchanger. Low pressure
A steam electrolysis-type hydrogen production apparatus using high-temperature steam as a raw material.

[0012]

The sodium-cooled fast breeder reactor plant according to the present invention is configured as described above, and heat exchangers (steam generators) are used for hot molten sodium heated and heated by nuclear heat of the fast breeder reactor and feed water. Heat exchange to generate high-pressure, high-temperature steam. (1) During the daytime when power demand is high, the steam switching valve on the hydrogen production device side is closed, and the steam switching valve on the power generation device side is opened, so that almost all of the steam from the heat exchanger is used for steam turbine power generation. Guide to the equipment steam turbine. (2) At midnight when power demand is low, the steam switching valve on the power generator side is closed and the steam switching valve on the hydrogen production side is opened, and almost the entire amount of steam from the heat exchanger is used for steam electrolysis hydrogen. It is led to the steam electrolyzer of the manufacturing equipment, or the exhaust gas of the steam turbine power generator is led to the heat exchanger provided in the steam system of the sodium-cooled fast breeder reactor plant, where it is reheated and the resulting low-pressure The high-temperature steam is led to the steam electrolyzer, where electric power is applied between the hydrogen electrode and the oxygen electrode to cause an electrochemical reaction in the steam to generate hydrogen gas and oxygen gas. ， Hydrogen gas is stored in a hydrogen storage tank.

[0013]

Next, a sodium-cooled fast breeder reactor plant according to the present invention will be described with reference to a first embodiment shown in FIG. This sodium-cooled fast breeder reactor plant is roughly classified into three systems: a system of the sodium-cooled fast breeder reactor 01, a system of the steam turbine power generator 11, and a system of the steam electrolysis hydrogen generator 21.

The operation is as follows. That is, the low-temperature molten sodium is led to the fast breeder reactor 02, where it is heated to 500 to 700 ° C. by nuclear heat and heated to a primary system / 2.
It is led to the secondary sodium / sodium heat exchanger 03, where the secondary sodium is heated and heated, while the cooled primary sodium is led to the same sodium / sodium heat exchanger 03 → pump (not shown). , Let's raise the pressure here,
It is led to the fast breeder reactor 02 again.

Further, the secondary sodium heated and heated by the steam sodium / sodium heat exchanger 03 is led to the steam generator 04, where the feedwater is heated to about 400 to 560 ° C. and the temperature is raised to remove steam. generate. Since the steam generator 04 is not a heat exchanger at a level of 800 to 1000 ° C. like a high temperature gas furnace, it is not necessary to use an expensive heat-resistant material such as a high temperature gas for the steam generator 04.

In the daytime when power demand is high, the steam switching valve 52 is closed and the steam switching valve 51 is opened, so that almost all of the steam from the steam generator 04 is supplied to the high-pressure steam turbine of the steam turbine power generator 11. 12 → Low pressure steam turbine 13
The steam turbines 12 and 13 drive a turbine generator 14 to convert thermal energy into electrical energy, and then to a condenser 16 where it is condensed and then condensed water (feed water) To the condensate pump 17, where the pressure is increased, and further increased by the water supply pump 06, and then again to the water supply pipe 53 → the steam generator 04. On the other hand, heat is applied to the feed water by the steam generator 04, and the temperature of the lowered secondary sodium is led to a pump (not shown), where the pressure is increased, and the primary / secondary sodium / sodium heat exchanger is returned again. Lead to 03.

The operation described above is performed during the daytime when power demand is high. At midnight when power demand is low, the steam switching valve 5 is used.
1, the steam switching valve 52 is opened, and the steam generator 0 is closed.
Almost all of the steam from the steam generator 4
2, the temperature is increased here, and then the steam is fed to a steam electrolyzer 22 as shown in FIG. The hydrogen gas is applied between the hydrogen electrode 23b and the oxygen electrode 23c to cause the following electrochemical reaction in the water vapor, and the hydrogen gas is supplied to the hydrogen electrode side manifold 26 side (this hydrogen gas is a mixed gas of water vapor and hydrogen; Called hydrogen hydrogen gas)
And oxygen gas (this oxygen gas is a mixed gas of air and oxygen and is called oxygen rich gas) on the oxygen electrode side manifold 27 side.

H 2 O → H 2 + 1 / 2O 2..., And the hydrogen gas generated in the hydrogen electrode side manifold 26 is supplied to a gas outlet 26 b → a steam heat exchanger. The inside of the outlet pipe 31 → the hydrogen rich gas expander 32 → the gas purifier 33 → the hydrogen storage tank 34, and is stored in the hydrogen storage tank 34. At this time, in the steam electrolyzer 22, only a part of the supplied steam contributes to the electrochemical reaction of the above formula, so that the gas flowing out from the gas outlet 26b of the hydrogen electrode side manifold 26 is not pure hydrogen but hydrogen. It becomes a rich gas (mixed gas of steam and hydrogen).

At this time, on the oxygen electrode 23c side, generated oxygen is positively discharged out of the system in order to promote the electrochemical reaction of the above formula. In other words, the atmosphere is changed from the air filter 48 to the air compressor 46 to the air-side heat exchanger 4.
5 → inlet pipe → gas inlet 27a of steam electrolysis device 22
→ After being guided to the oxygen electrode side manifold 27 to be combined with the electrolytic oxygen, it is discharged out of the system through the gas outlet 27 b → inside the outlet tube of the air side heat exchanger 45 → through the oxygen rich gas expander 47. Throughout the day, power generation and hydrogen production are as shown in FIG.

FIG. 2 shows the details of the steam electrolyzer 22. Reference numeral 23 denotes a reaction three-layer film.
Is composed of an electrolyte 23a, a hydrogen electrode 23b, and an oxygen electrode 23c. The electrolyte 23a is made of yttria-stabilized zirconia (YSZ), the hydrogen film 23b is made of a nickel porous plate, and the oxygen electrode 23c is made of lanthanum manganite (LaMnO3). A board is used. Reference numeral 24 denotes a power supply line in contact with the hydrogen film 23b and the oxygen electrode 23c, reference numeral 26 denotes a hydrogen electrode-side manifold formed on the hydrogen film 23b side, reference numeral 27 denotes an oxygen electrode-side manifold formed on the oxygen electrode 23c side, 26a Is the gas inlet of the hydrogen electrode side manifold 26 connected to the inside of the inlet tube of the steam heat exchanger 31, 26b is the gas outlet of the hydrogen electrode side manifold 26 connected to the inside of the outlet tube of the steam heat exchanger 31, and 27a is the gas outlet. The gas inlet of the oxygen electrode side manifold 27 connected to the inside of the outlet tube of the air side heat exchanger 45 is the gas outlet of the oxygen electrode side manifold 27 connected to the inside of the inlet tube of the steam heat exchanger 31.

Next, a sodium-cooled fast breeder reactor plant according to the present invention will be described with reference to a second embodiment shown in FIGS. This embodiment can also be roughly classified into three systems as shown in FIG. 3, that is, a system of a sodium-cooled fast breeder reactor 01, a system of a steam turbine power generator 11, and a system of a steam electrolysis hydrogen generator 21. Although it is constituted by a system, it differs from the first embodiment in the following points. (1) Steam generator 04 using secondary sodium as heat source
Is divided into a high-pressure steam generator and a low-pressure steam generator. (2) According to the above item (1), the high-pressure steam turbine 12
The exhaust gas is guided to a low-pressure steam generation section provided in the steam generator 04, converted into high-temperature reheated steam, and guided to the low-pressure steam turbine 13. (3) According to the above items (1) and (2), the steam switching valve 5
1 and 52 are provided in high-temperature reheat steam lines (steam supply pipes) 54b and 54c having a low pressure.
Are not provided with the steam switching valves 51 and 52. (4) As the operating pressure of the steam electrolyzer 22 decreases, the gas expander (see 32 in FIG. 1) in the hydrogen-rich gas system on the outlet side is abolished, and the condenser 38 is used instead.
Is provided to effectively remove moisture in the hydrogen rich gas. As the cooling water, a part of the cooling water of the cooling water facility of the steam turbine power generator 11 is used. (5) Since it is desirable to lower the gas pressure in the oxygen electrode side manifold 27 with a decrease in the operating pressure as in the above item (4), the pressing by the compressor (see 45 in FIG. 1) is stopped, and Is provided with a vacuum pump 49 and a storage tank 40, and O2 is stored in the storage tank 40.
To save.

Due to the differences in the above items (1) to (5), in the second embodiment, the high-temperature reheat steam lines (steam supply pipes) 54b, 54 having a low pressure are used during nighttime when power demand is small.
c, only the steam switching valves 51 and 52 are operated, so that the water supply pipe 53 → the steam generator 04 → the high pressure steam turbine 13
The power generation in this system will be stopped. The low-pressure high-temperature steam sent through the steam switching valve 52 is led to the heat exchanger 31 of the steam electrolysis-type hydrogen production apparatus 21, heated and heated, and then led to the steam electrolysis apparatus 22, where it is converted into a hydrogen rich gas and heat exchanged. Vessel 31 → heat exchanger 32 → condenser 38 →
The compressor 36 is guided to the H2 storage tank 34 and stored therein.

FIG. 4 shows the details of the steam generator 04. This steam generator 04 is composed of substantially the same five steam generators 04a, 04b, 04c, 04d, and 04e. During the daytime when power demand is high, valves 57 and 5
8, the valves 59 and 60 are closed, and two steam generators 04
a and 04b, high-pressure steam is obtained and guided to the high-pressure steam turbine 12, and the remaining three steam generators 04c and 0b
By obtaining low-pressure steam at 4d and 04e and guiding the low-pressure steam to the low-pressure steam turbine 13, the load balance of the high-pressure steam turbine 12 and the low-pressure steam turbine 13 is properly maintained.

On the other hand, at night or the like when power demand is small, the valves 57, 58, 59 and 60 are opened and closed due to the difference between the operating pressure of the steam electrolysis device 22 and the inlet pressure of the low-pressure steam turbine 13. That is, if the operating pressure of the steam electrolysis device 22 and the inlet pressure of the low-pressure steam turbine 13 are the same, the valve 5
7 to 60 do not basically require any operation. The low-pressure steam turbine 13 is stopped and the steam electrolysis device 22 is operated by opening and closing the steam switching valves 51 and 52 provided in the branched steam supply pipes 54b and 54c. I do.

When the operating pressure of the steam electrolyzer 22 is lower than the inlet pressure of the low-pressure steam turbine 13,
The valves 57 and 58 are closed, and the valves 59 and 60 are opened. This reduces the heat input to the high-pressure steam system, reducing the steam flow,
Alternatively, one of the two methods, that is, lowering the steam temperature, is selected, and the operation is appropriately performed. On the other hand, in the low-pressure steam system, although the heat transfer area increases with the increase in the number of steam generators 4 (3 → 4), the heat transfer coefficient also decreases due to the decrease in steam pressure. Is sent to the steam electrolysis device 22.

The power generated by the high-pressure steam turbine 12 is
It may be applied to part of the electric power required by the steam electrolysis-type hydrogen production apparatus 21. In the second embodiment shown in FIGS. 3 and 4, the steam generator 4 is composed of five steam generators 04a to 04e, but it is sufficient if there are two or more steam generators. Each of the steam generators 04a to 04a
e may have different specifications.

Next, a sodium-cooled fast breeder reactor plant of the present invention will be described with reference to a third embodiment shown in FIG. This embodiment can also be roughly classified into three systems, namely, a system of the sodium-cooled fast breeder reactor 1 and a system of the steam turbine power generator 1.
1 and the system of the steam electrolysis-type hydrogen production apparatus 21, but differ from the second embodiment in the following points. (1) A plant whose primary purpose is to produce hydrogen regardless of fluctuations in power demand. (2) The steam turbine generator 11 is composed of only the back-pressure steam turbine 12, a DC generator is used as a generator, and a power cable is organically connected so as to directly supply the power to the steam electrolyzer 22. . Further, the back pressure steam turbine 12 and the hydrogen gas compressor 36 were mechanically connected. (3) The heat exchangers 32 and 45 and the water supply line are organically connected so as to use the retained heat of the gas from the steam electrolytic hydrogen production apparatus 21 for preheating the water supply to the steam generator 04. .

In this sodium-cooled fast breeder reactor plant, a fixed amount of high-pressure steam is constantly supplied to the steam turbine power generator 1.
1 to generate electricity, and the entire amount of the exhaust gas is reheated by the steam generator 04, then led to the heat exchanger 31 → the steam electrolysis device 22, where the DC power generates hydrogen to generate hydrogen. The hydrogen rich gas is led to a condenser 38 where water is removed, guided to a compressor 36, where the pressure is increased, and then guided to an H2 storage tank 34 where it is stored. Oxygen generated simultaneously with the generation of hydrogen is led to the O2 storage tank 40 via the heat exchanger 45 and the vacuum pump 49 and stored therein.

The steam electrolytic hydrogen production apparatus 21 for producing hydrogen according to each of the above embodiments may be used as a generator (fuel cell) when power demand is large, such as during the daytime. In each of the above embodiments, the primary and secondary medium of the fast breeder reactor 02 is sodium, but a mixture of sodium and potassium or potassium may be used instead of sodium.

[0030]

As described above, the sodium-cooled fast breeder reactor plant of the present invention heat-exchanges the high-temperature molten sodium heated and heated by the nuclear heat of the fast breeder reactor and the feed water with a heat exchanger (steam generator). To generate high-pressure, high-temperature steam.
(1) During the daytime when power demand is high, the steam switching valve on the hydrogen production device side is closed, and the steam switching valve on the power generation device side is opened, so that almost all of the steam from the heat exchanger is used for steam turbine power generation. Guide to the equipment steam turbine. (2) At midnight when power demand is low, the steam switching valve on the power generator side is closed and the steam switching valve on the hydrogen production side is opened, and almost the entire amount of steam from the heat exchanger is used for steam electrolysis hydrogen. It is led to the steam electrolyzer of the manufacturing equipment, or the exhaust gas of the steam turbine power generator is led to the heat exchanger provided in the steam system of the sodium-cooled fast breeder reactor plant, where it is reheated and the resulting low-pressure The high-temperature steam is led to the steam electrolyzer, where electric power is applied between the hydrogen electrode and the oxygen electrode to cause an electrochemical reaction in the steam to generate hydrogen gas and oxygen gas. Since the hydrogen gas is stored in the hydrogen storage tank, the following effects can be achieved. (A) It is easy to respond to fluctuations in power demand. (B) In addition, the sodium-cooled fast breeder reactor, the steam turbine-type power generator, and the steam electrolysis-type hydrogen production system are organically connected, so that hydrogen can be produced efficiently. (C) In addition, a steam electrolysis-type hydrogen production system, which used to be a high-temperature gas-cooled nuclear reactor as a heat source, is located downstream of this plant, so that the set temperature of the steam pipe connecting the reactor and the hydrogen production system can be greatly increased. Therefore, the cost of producing hydrogen can be further reduced by the steam electrolytic hydrogen production plant. (D) When viewed from the steam electrolysis type hydrogen production apparatus side, the heat transport pipe provided between the distant heat source apparatus side requires an expensive heat-resistant material when the heat source is HTGR. Since less expensive materials can be used, there is an effect that the manufacturing cost of the plant can be reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a first embodiment of a sodium-cooled fast breeder reactor plant according to the present invention.

FIG. 2 is a vertical sectional side view showing details of the steam electrolytic hydrogen production apparatus of the first embodiment.

FIG. 3 is a system diagram showing a second embodiment.

FIG. 4 is a vertical sectional side view showing details of the heat exchanger of the second embodiment.

FIG. 5 is a system diagram showing a third embodiment.

FIG. 6 is an explanatory diagram showing a state of daily power generation and hydrogen production in the first embodiment.

FIG. 7 is a system diagram showing a conventional sodium-cooled fast breeder reactor plant.

[Explanation of symbols]

01 sodium-cooled fast breeder reactor 02 fast breeder reactor 03 primary / secondary sodium / sodium heat exchanger 04 heat exchanger (steam generator) 11 steam turbine power generator 12 high-pressure steam turbine 13 low-pressure steam turbine 21 steam Electrolytic hydrogen production apparatus 51 Steam switching valve (switching means) 52 Steam switching valve (switching means) 53 Feedwater supply pipe 54a Steam outlet side of heat exchanger 04 54b Steam supply pipe 54c Steam supply pipe (second steam supply pipe)

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Seiichi Tanabe 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (72) Inventor Yuji Tokita 1-1-1, Akunoura-cho, Nagasaki-shi, Nagasaki Shinichi Nagai, Examiner, Nagasaki Research Laboratory, Kogyo Co., Ltd. (56) References JP-A-58-96296 (JP, A) JP-A-59-48696 (JP, A) Naoto Fukuyama et al. “Hydrogen energy using high-temperature steam electrolysis method” System, IEICE New Energy Conservation Study Group, ESC-90 (1990) p. 55-65 (58) Field surveyed (Int. Cl. ⁷ , DB name) G21D 9/00 C25B 1/04 C25B 9/00 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A steam turbine power generator driven by high pressure and high temperature steam sent from a heat exchanger provided in a steam system of a sodium-cooled fast breeder reactor, and an exhaust gas of the steam turbine power generator is subjected to the heat exchange. A fast-breeding sodium-cooled breeder reactor, comprising: a steam electrolysis-type hydrogen production apparatus using low-pressure, high-temperature steam obtained by reheating with a vessel.