JP2001235585A - Regional cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regional cogeneration system supplying the hot heat and cold heat to the region and enhancing the total heat efficiency of a nuclear power generation plant. SOLUTION: This regional cogeneration system is provided with a nuclear power generating system 1 having a heat exchanger 11 supplied branched steam generated in a nuclear reactor 6 and introduced to a steam turbine 7 for driving a power generator 8, a steam storage tank 13 installed in a place separated from the nuclear power generating system 1 and receiving and storing the steam generated from circulating water for exchanging the heat in the heat exchanger 11 of the nuclear power generating system 1, a storage steam power generating system 2 having a steam turbine 14 for power generation driven using the steam stored in the steam storage tank 13, and a regional heat supply system 3 supplied the circulating water for exchanging the heat with exhaust of the steam turbine 14 of the storage steam power generating system 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regional cogeneration system for performing power generation corresponding to peak power demand and district heat supply using steam generated in a nuclear reactor of a nuclear power plant.

[0002]

2. Description of the Related Art As a regional cogeneration system provided up to now, steam generated by exchanging heat with a turbine converter at the Kanan Electric Power Co., Inc. Hainan Thermal Power Station adjacent to Wakayama Marina City is sent to a local cogeneration system. Some are supplying heat. This regional cogeneration system supplies steam for heating and hot water supply directly, and supplies cold water produced by an absorption refrigerator using steam.

[0003] In nuclear power plants, base load operation is performed because of low power generation costs. Due to daily load fluctuations in power demand, hydropower and oil-fired power plants are used for peak power demand. In the case of hydroelectric power generation, there are problems such as a remote location, environmental destruction, and a long construction period. In the case of oil-fired power generation, there is a problem of global warming due to carbon dioxide emission.

[0004] To cope with daily load fluctuations while taking advantage of the features of a nuclear power plant, a system for storing the produced steam and generating electricity with the stored steam for peak power demand has been studied. By extracting and storing 20% of steam during 10 hours at night and by generating 20% additional power during 7 hours during the day, it is possible to respond to load fluctuations, and the storage and power generation efficiency (72.6%) is comparable to that of the PSPP. It is evaluated that it can be obtained. 1.1M
In the case of kW-class nuclear power plant, storage container of 4040m ³
21 units will be set up on a 114 mx 54 m site. The inner diameter of the container at that time is 11.5 m, and the height is 44.2 m.

[0005]

In the above-mentioned conventional district heat supply, the load density is 40 MW due to high piping cost.
/ Km ² or more, and about 5000 households living in 1 km ² is a condition for economic viability. For this reason, there is a problem that district heat supply cannot be provided in every region.

[0006] A method of installing a steam storage container in a nuclear power plant and storing the steam produced at night and using it for power generation in response to peak power demand in the daytime destroys the environment like a pumped storage power plant. Although there is no problem such as the lack of a long and suitable location, the thermal efficiency of the nuclear power plant is about 33.4%, and 50% of the gas turbine combined power plant.
The problem remains that it is very low compared to those exceeding.

[0007] In order to solve this problem, it has been found that the total thermal efficiency can be easily increased to 60% or more by supplying thermal energy produced in a nuclear power plant not only to power generation but also to direct heat utilization. I have. It is said that a system utilizing direct heat is economically feasible if the power is supplied to a power plant within a range of about 1 km from the viewpoint of heat transfer efficiency. However, nuclear power plants are generally located in areas far from large cities, so there is no close demand for heat to improve overall thermal efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional circumstances, and has as its object to provide a local cogeneration system that can supply hot or cold heat to an area and increase the overall thermal efficiency of a nuclear power plant. I do.

[0009]

According to the present invention, there is provided a nuclear power generation system having a heat exchanger that branches and supplies steam generated in a nuclear reactor and guided to a steam turbine that drives a generator. A steam storage tank that is installed at a location remote from the nuclear power generation system and stores steam generated from circulating water that performs heat exchange in the heat exchanger of the nuclear power generation system, and steam stored in the steam storage tank. A storage steam power generation system having a driven steam turbine and a district heat supply system supplied with circulating water that exchanges heat with the exhaust of the steam turbine of the storage steam power generation system are provided.

According to the regional cogeneration system of the embodiment of the present invention, the power generation corresponding to the load fluctuation is performed by the storage steam power generation system, the exhaust heat is supplied to the area, and the overall thermal efficiency of the nuclear power plant can be improved. .

The invention corresponding to claim 2 is provided with a heat exchanger at the outlet of the steam turbine of the nuclear power generation system, and drives the steam turbine of the storage steam power generation system to guide the reconstituted water to the heat exchanger. After the heat exchange is performed in the heat exchanger, the heat generated is guided to the heat exchanger of the branch steam of the steam generated in the nuclear reactor to perform the heat exchange. ADVANTAGE OF THE INVENTION According to this invention, the waste heat of a nuclear power generation system can be collect | recovered and circulating water between a storage steam power generation system can be heated efficiently.

According to a third aspect of the present invention, the district heat supply system includes an absorption chiller, and diverges steam from a steam storage tank of the storage steam power generation system and guides it to the absorption chiller to produce a refrigerant. The cooling water is supercooled with the district heat demand facility to produce and store ice, and the stored ice is taken out in the form of a slurry to supply cold heat. According to the present invention, it is possible to efficiently supply cold heat from a district heat supply system to a district heat demand facility.

According to a fourth aspect of the present invention, a heat supply subsystem is provided in a steam pipe and a circulating water pipe connecting the nuclear power generation system and the storage steam power generation system, and the heat supply subsystem has a steam storage tank. Then, the stored steam is taken out to exchange heat with circulating water with the district heat demand facility.

According to the present invention, heat can be efficiently supplied to a relatively small-scale heat demanding facility located in the middle of a heat transport line from a nuclear power generation system to a storage steam power generation system.

According to a fifth aspect of the present invention, the heat supply subsystem includes an absorption chiller, and the steam in the steam storage tank is guided to the absorption chiller to produce a refrigerant. Ice is produced and stored by supercooling the circulating water with the facility, and the stored ice is taken out in a slurry form to supply cold heat.

According to the present invention, it is possible to efficiently supply cold heat to a relatively small-scale heat demanding facility located in the middle of a heat transport line from a nuclear power generation system to a storage steam power generation system.

According to a sixth aspect of the present invention, the storage steam power generation system is buried underground. The invention corresponding to claim 7 has a configuration in which the heat supply subsystem is buried underground. According to the invention of claim 6 or 7, it is possible to protect the greenery on the ground and harmonize with the surrounding scenery.

According to an eighth aspect of the present invention, a steam pipe and a circulating water pipe connecting the nuclear power generation system and the storage steam power generation system are installed in the sea or on the riverbed. ADVANTAGE OF THE INVENTION According to this invention, a heat transport line can be laid cheaply and efficiently.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A local cogeneration system according to a first embodiment of the present invention branches steam generated in a nuclear power plant at night and exchanges heat with circulating water to a storage steam power generation system to generate steam. The steam is generated, transported over long distances, stored in the steam storage tank of the storage steam power generation system, taken out when peak power demand occurs during the day, and the steam turbine is rotated to generate power corresponding to the peak power demand. Exhaust steam is exchanged with the circulating water of the district heat supply system to supply heat to the area, thereby performing load leveling and district heat supply.

Hereinafter, the local cogeneration system of the first embodiment will be described in detail with reference to FIG. FIG.
The steam is transported from the nuclear power generation system 1 to the storage steam power generation system 2 and stored to perform peak power generation, and the turbine exhaust heat is led to the district heat supply system 3 to supply the district heat demand facility 5
FIG. 2 shows the flow of steam and water which is used to supply heat to the heat supply subsystem 4 by branching steam transported from the nuclear power generation system 1 to the storage steam power generation system 2.

The nuclear power generation system 1 comprises a boiling water reactor 6, a steam turbine 7, a generator 8, a condenser 9, a circulation pump 10, heat exchangers 11 and 12, and the like. The steam generated in the reactor 6 is branched and split into a steam turbine 7 and a heat exchanger.
The steam that is guided to 11 and drives the steam turbine 7 is guided to the heat exchanger 12, performs heat exchange with circulating water from the storage steam power generation system 2, is guided to the condenser 9, and is cooled by seawater or the like. To return to water.

The steam branched in front of the steam turbine 7 is led to the heat exchanger 11 and exchanges heat with the circulating water after heat exchange with the exhaust gas of the steam turbine 7 sent from the storage steam power generation system 2. The liquid is condensed with the condensate of the condenser 9 and returned to the reactor 6 by the circulation pump 10.

The storage steam power generation system 2 includes a steam storage tank 1
3, steam turbine 14, generator 15, heat exchanger 16, water tank 1
7. It is composed of a circulation pump 18 and the like. The circulating water pressurized by the circulation pump 18 is supplied to the heat exchanger 12 of the nuclear power generation system 1,
11 to perform heat exchange to convert the steam to steam, transport the steam over a long distance, and store the steam stored in the steam storage tank 13 during the daytime when peak power demand occurs.
The exhaust gas exchanges heat with the circulating water from the district heat supply system 3 in the heat exchanger 16 to recover the liquid, and is stored in the water storage tank 17.

The district heat supply system 3 includes a water storage tank 19, a circulation pump 20, a hot water storage tank 34, a circulation pump 35, and the like. The circulating water stored in the water storage tank 19 is led to the heat exchange section of the heat exchanger 16 of the storage steam power generation system 2 to generate hot water, and is stored in the hot water storage tank 34. When heat demand is generated in the district heat demand facility 5, the hot water in the hot water storage tank 34 is transported by pressurizing with the circulating pump 35, and the circulating water that has been cooled by the heat exchange is stored in the water storage tank 19.

The heat supply subsystem 4 includes a steam storage tank 21,
It is composed of a heat exchanger 22, a water storage tank 36, circulation pumps 23 and 37, and the like. From nuclear power generation system 1 to storage steam power generation system 2
The steam is branched from the steam transport pipe 25 to the steam storage tank 21 and stored in the steam storage tank 21. To return the condensed water from the storage steam power generation system 2 to the return water pipe 26 to the nuclear power generation system 1. When heat demand is generated in the district heat demand facility 24, the steam stored in the steam storage tank 21 is taken out and the heat exchanger is taken out.
22 and circulates water from district heat demand facility 24
It is pressurized at 23 and flows through the heat exchanger 22 for heating.

FIG. 2 shows the location concept of the regional cogeneration system of the first embodiment, and the nuclear power generation system 1
The steam is transported to the storage steam power generation system 2 while being supplied to the heat supply sub-center 29 on the way via the underwater laying pipe 30 and the riverbed buried pipe 31, thereby performing power generation and district heat supply.

The underwater laying pipe 30 is laid with a neutral buoyancy at a depth of about 20 m, which is the limit of sunlight reach. When laying the riverbed buried pipe 31, a method of digging a groove of about 2m depth in the riverbed, assembling the pipe with the pipe floating on the river, removing buoyancy at the stage when the groove is dug, and installing at once in the groove is adopted.

The heat supply sub-center 29 and the storage steam power generation system 2 are buried underground. On top of that, in addition to the house cultivation facility 33 and the plant factory 32, horticultural treatment facilities, hot spring facilities, skating rink facilities, frozen storage facilities, liquid air separation Facilities will be set up to harmonize with the surrounding landscape. Further, the heat supply sub-center 29 is installed in a schoolyard, a park, a basement of a parking lot around a hospital, or the like to have a function as a disaster prevention base.

The local cogeneration system according to the first embodiment of the present invention configured as described above operates as follows. That is, when nighttime power demand is low, about 20% of the steam generated in the reactor 6 is branched and led to the heat exchanger 11. The steam led to the heat exchanger 11 is stored in the storage steam power generation system 2. The water stored in the tank 17 is returned by the circulation pump 18, exchanges heat with the circulating water sent via the water pipe 26 or the riverbed buried pipe 31 and the submerged laying pipe 30, and is returned to the circulation pump.
Guided to the 10 entrance side. The circulating water that has undergone heat exchange in the heat exchanger 11 is vaporized, transported and stored in the steam storage tank 13 of the storage steam power generation system 2 via the steam transport pipe 25 or the riverbed buried pipe 31 and the underwater pipe 30. The steam is branched from the middle of the steam transport pipe 25 and stored in the steam storage tank 21 of the heat supply subsystem 4.

During the daytime when the peak of the power demand occurs, the steam generated in the nuclear reactor 6 of the nuclear power generation system 1 is not branched to the heat exchanger 11 but all the steam is led to the steam turbine 7 to drive it. Then, power is generated by the generator 8 coaxially coupled. In addition, the steam stored in the steam storage tank 13 of the stored steam power generation system 2 is taken out and guided to a steam turbine 14, which is driven to generate electric power by a coaxially coupled generator 15 to meet peak power demand.

The exhaust gas of the steam turbine 14 is sent to a heat exchanger 16, and the water stored in a water storage tank 19 of the district heat supply system 3 is pressurized by a circulation pump 20 and sent there. The water is condensed by performing heat exchange in the exchange unit and stored in the water storage tank 17. The circulating water for district heat supply heated by the heat exchanger 16 is stored in a hot water storage tank 34, and heat of the district heat demand facility 5 consisting of a house cultivation facility, a plant factory, a horticultural treatment facility, a hot spring facility, a general home, and the like. Supply hot water according to demand. The circulating water that has been cooled down by performing heat exchange in the district heat demand facility 5 returns to the water storage tank 19 and is stored therein.

The steam stored in the steam storage tank 21 of the heat supply subsystem 4 at night is house cultivation facility, plant factory, horticultural treatment facility, hot spring facility, skating rink facility, frozen storage facility, liquid air separation facility, school, The heat is exchanged in the heat exchange section where the circulating water for district heat supply, which is guided to the heat exchanger 22 according to the demand of the district heat demand facility 24 composed of a hospital, a general home, etc. and is sent from the district heat demand facility 24, flows. Condensate. This condensed water is stored in a water storage tank 36 and returned to the water pipe by a circulation pump 37 at night.
Returning to 26, it is used for generating steam in the nuclear power generation system 1.

The local cogeneration system of the first embodiment, which operates according to the above configuration, has the following effects. That is, heat energy generated in the nuclear power generation system 1 is exchanged with heat, extracted with steam, and the turbine 14 is driven to generate power, thereby meeting peak power demand. In addition, by performing heat exchange of the turbine exhaust steam at that time with the district heat supply circulating water and supplying heat to the area,
Since the exhaust heat can be supplied as heat to the periphery of the stored steam power generation system 2, the overall thermal efficiency of the nuclear power generation system 1 can be increased.

Further, by installing a large-capacity heat demanding facility such as the storage steam power generation system 2 farther from the installation position of the nuclear power generation system 1, steam can be sequentially supplied to a small number of heat demanding facilities during heat transport. Can be supplied. Since heat can be efficiently supplied in this manner, a wide-area heat supply system can be economically constructed even in an area where the heat demand is small. By installing a storage steam power generation system with high heat demand from the beginning to transport steam over long distances and use heat regardless of the construction of heat demand facilities on the way, conventional heat demand facilities can be used with wide area heat utilization. The problem that the operation of the building became difficult because the construction of the building did not go as planned can be resolved.

In many cases, the nuclear power generation system 1 is installed at a place away from a densely populated area such as the tip of a peninsula, but it is necessary to lay a heat transport pipe at a depth of about 20 m underwater with neutral buoyancy. Accordingly, heat can be efficiently transported to a densely populated area over a short distance. In addition, by burying pipes at the bottom of the river, laying work is facilitated, and there is no need to acquire land, and system construction can be achieved in a short time.

FIG. 3 shows a second embodiment of the present invention. Instead of the district heat supply system 3 of FIG. 1 described above, refrigerant supplied by branching the steam from the steam storage tank 13 is supplied. The heat supply system 43 includes a generation system 38, a high-temperature water generation system 39, and a hot water generation system 41 using heat from the heat exchanger 16, and a refrigerant is used instead of the heat supply subsystem 4 in FIG. Generation system 40 and hot water generation system
It shows the flow of a regional cogeneration system as a heat supply subsystem 44 with 42.

The hot water generation system 41 in the heat supply system 43
Has the same configuration as the heat supply system 3 of FIG. The high-temperature water generation system 39 includes a heat exchanger that guides the steam branched from the steam storage tank 13, a pressure pump that supplies water to a heat exchange unit of the heat exchanger, and the like. The return water from the district heat demanding facility 5 is pressurized by the pressurizing pump and guided to the heat exchanging section, and performs heat exchange with steam to become high-temperature water, which is guided to the district heat demanding facility 5.

The refrigerant generation system 38 comprises an absorption refrigerator, a subcooler, a subcooling release tank, an ice storage tank, a water pump, a water storage tank, and the like. Guides the branch steam to the absorption refrigerator, generates the refrigerant, guides it to the supercooler, puts the water guided from the water storage tank into a supercooled state, and guides it to the subcooling release tank to release the supercooling and generate ice. And store in an ice storage tank. The stored ice is made into an ice slurry and supplied to the district heat demand facility 5. The water that has exchanged heat in the district heat demand facility 5 returns to the water storage tank 17 and is stored.

The heat supply subsystem 44 includes the steam storage tank 21,
It is composed of a refrigerant generation system 40 and a hot water generation system 42. The refrigerant generation system 40 includes an absorption refrigerator, a subcooler, a subcooling release tank, a water pump, a water storage tank, and the like. The hot water generation system 42 has the same configuration as the heat supply subsystem 4 of FIG. 1 including the heat exchanger 22, the circulation pumps 23, and the water tank 36.

According to the regional cogeneration system of the second embodiment, it is possible to generate power in response to load fluctuations, supply heat to the area, and supply cool heat to the area. By doing so, nuclear power system 1
Overall thermal efficiency throughout the year.

[0041]

According to the regional cogeneration system of the embodiment of the present invention, it is possible to supply hot or cold heat to the area and to increase the overall thermal efficiency of the nuclear power plant.

[Brief description of the drawings]

FIG. 1 is a flowchart of a local cogeneration system according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a location of the local cogeneration system according to the first embodiment of the present invention.

FIG. 3 is a flowchart of a regional cogeneration system according to a second embodiment of the present invention.

[Explanation of symbols]

1. Nuclear power generation system, 2. Storage steam power generation system,
3 ... district heat supply system, 4 ... heat supply subsystem, 5
… District heat demand facility, 6… Reactor, 7… Steam turbine, 8
... generator, 9 ... condenser, 10 ... circulation pump, 11 ... heat exchanger, 12 ... heat exchanger, 13 ... steam storage tank, 14 ... steam turbine, 15 ... generator, 16 ... heat exchanger, 17 … Water tank, 18… circulation pump, 19… water tank, 20… circulation pump, 21… steam storage tank, 22… heat exchanger, 23… circulation pump, 24… district heat demand facility, 25… steam transport piping, 26 … Return water piping, 29… Heat supply sub-center, 30… Submerged piping, 31… River bottom buried piping, 32…
Plant factory, 33… House cultivation facility, 34… Hot water storage tank, 35…
Circulation pump, 36 ... water storage tank, 37 ... circulation pump, 38 ... refrigerant generation system, 39 ... high temperature water generation system, 40 ... refrigerant generation system, 41 ... hot water generation system, 42 ... hot water generation system, 43 ... heat supply system, 44… Heat supply subsystem.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Miyazawa 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Head Office (72) Inventor Hideaki Hioki 8-8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa F-term in Toshiba Yokohama Office (reference) 3L093 AA01 BB26

Claims (8)

[Claims] 1. A nuclear power generation system having a heat exchanger that branches and supplies steam generated in a nuclear reactor and guided to a steam turbine that drives a generator, and a heat exchanger installed at a location remote from the nuclear power generation system. A storage steam power generation system having a steam storage tank for storing steam generated from circulating water that performs heat exchange in a heat exchanger of a nuclear power generation system and a steam turbine driven using the steam stored in the steam storage tank; A regional cogeneration system comprising: a district heat supply system supplied with circulating water for exchanging heat with exhaust gas from a steam turbine of the storage steam power generation system. 2. A heat exchanger is provided at an outlet of a steam turbine of a nuclear power generation system, and a steam turbine of a storage steam power generation system is driven to guide condensed water to the heat exchanger, where heat exchange is performed. 2. The local cogeneration system according to claim 1, wherein the heat exchange is performed by conducting the heat exchange to a heat exchanger of a branch steam of the steam generated in the nuclear reactor. 3. The district heat supply system includes an absorption chiller. The steam in the steam storage tank of the storage steam power generation system is branched and guided to the absorption chiller to produce a refrigerant. 2. The regional cogeneration system according to claim 1, wherein the circulating water with the facility is supercooled to produce and store ice, and the stored ice is taken out in a slurry form to supply cold heat. 4. A heat supply subsystem is provided in a steam pipe and a circulating water pipe connecting the nuclear power generation system and the storage steam power generation system. The heat supply subsystem has a steam storage tank, and the stored steam is taken out. 2. The local cogeneration system according to claim 1, wherein heat exchange is performed with circulating water with a district heat demand facility. 5. The heat supply subsystem includes an absorption chiller, and guides the steam in the steam storage tank to the absorption chiller to produce a refrigerant, and the refrigerant circulates water with a district heat demand facility. 5. The local cogeneration system according to claim 4, wherein the ice is produced by cooling and stored, and the stored ice is taken out in a slurry form to supply cold heat. 6. The local cogeneration system according to claim 1, wherein the stored steam power generation system is buried underground. 7. The regional cogeneration system according to claim 4, wherein the heat supply subsystem is buried underground. 8. The local cogeneration system according to claim 1, wherein a steam pipe and a circulating water pipe connecting the nuclear power generation system and the storage steam power generation system are installed in the sea or on the riverbed.