KR20220099385A - Nuclear power load response generation system using solar heat - Google Patents

Abstract

The present invention relates to a nuclear load-responding generation system, which can improve load-responding capability of a nuclear power plant, comprising: a solar thermal storage system that stores solar thermal energy using a heat transfer fluid; a heat exchanger that performs heat exchange between steam from the secondary system of nuclear power generation and the heat transfer fluid from the solar thermal storage system; a water electrolysis device that separates the steam having passed through the heat exchanger into oxygen (O_2) and hydrogen (H_2) using a predetermined water electrolysis technique; and a turbine power generation system that produces load-responding power by combustion reaction between the steam from the secondary system of nuclear power generation, and oxygen (O_2) and hydrogen (H_2) separated through the water electrolysis device.

Description

A power generation system that responds to a nuclear load using solar heat {NUCLEAR POWER LOAD RESPONSE GENERATION SYSTEM USING SOLAR HEAT}

The present invention relates to a nuclear load response power generation system, and more particularly, to a nuclear load response power generation system capable of performing hydrogen production and load response generation using solar thermal energy of a solar power plant.

A nuclear power plant is a power plant that uses nuclear power to produce electricity. It is a place equipped with a facility to generate electricity using the energy released when an atomic nucleus decays or undergoes a nuclear reaction.

1 is a diagram showing the system structure of a typical nuclear power plant. As shown in FIG. 1 , the nuclear power plant 10 may be composed of a primary system 11 , which is a nuclear steam-related facility system, and a secondary system 12 , which is a turbine generator-related facility system. .

The primary system 11 is a core system of a nuclear power plant that uses light water as a moderator and a coolant, and generates steam through a steam generator by absorbing heat from a fuel bundle in the nuclear reactor. The primary system 11 is a reactor coolant system that circulates pressurized coolant to transfer the heat of nuclear reaction generated in the reactor core to a steam generator, and a chemical and volume control system that maintains appropriate purity by controlling the chemical composition and volume of the coolant , it is composed of a safety injection system that injects boric acid water, which is a neutron absorbing material, and emergency coolant in case of a virtual accident such as a loss of coolant, other nuclear fuel handling systems, and instrumentation and control systems.

The secondary system 12 is a system that converts thermal energy of steam generated through a steam generator in the nuclear steam supply system into power, that is, electrical energy, and is similar to that of a general thermal power plant.

Nuclear power generation with such a system structure can obtain enormous energy with a small amount of nuclear fuel, and unlike fossil fuels, there is no emission of environmental pollutants such as carbon dioxide (CO ₂ ), so continuous development is inevitable in terms of environmental conservation. .

Meanwhile, in recent years, as environmental pollution and global warming problems due to the use of fossil fuels have emerged, the importance of technology for producing hydrogen, which is an alternative energy source that can replace fossil fuels and a clean energy source that does not generate greenhouse gases, is increasing. is being highlighted. Accordingly, several countries around the world are spurring the development of hydrogen production technology. In addition, as carbon emissions are compulsorily reduced according to international climate agreements, the proportion of new and renewable energy is gradually increasing. Due to the increase in solar energy among these new and renewable energies, when solar energy reaches its maximum at noon, there is an oversupply in the power system, and the existing power generation systems have to reduce the amount of power generation.

However, in the case of conventional thermal power generation or gas power generation, it is easy to control the output, but in the case of nuclear power generation, it is not easy to reduce the output due to the health problems of the primary system nuclear fuel and cladding, and there is a problem that the load response ability is lowered. Therefore, when an oversupply occurs according to the output variability of the renewable energy source on the power system, a method of utilizing the surplus energy of the nuclear power plant while minimizing the impact on the primary system of the nuclear power plant is required.

SUMMARY OF THE INVENTION The present invention aims to solve the above and other problems. Another object of the present invention is to provide a nuclear load response power generation system capable of improving the load response capability of a nuclear power plant when a load of a power system changes.

Another object is to use the solar energy of the solar power plant to produce hydrogen from the transient steam branched from the secondary system of nuclear power generation, and to provide a nuclear load response power generation system capable of performing load response generation based on the produced hydrogen. is in

According to an aspect of the present invention to achieve the above or other objects, a solar thermal storage system for storing solar energy using a heat transfer fluid; a heat exchanger for performing heat exchange between steam flowing in from a secondary system of nuclear power and a heat transfer fluid flowing in from the solar storage system; a water electrolysis device for separating the vapor that has passed through the heat exchanger into oxygen (O ₂ ) and hydrogen (H ₂ ) using a predetermined water electrolysis technique; and a turbine power generation system for generating load-responding power through a combustion reaction between steam introduced from the secondary system of the nuclear power plant, and oxygen (O ₂ ) and hydrogen (H ₂ ) separated through the water electrolysis device. Provided is a nuclear load response power generation system. Here, the predetermined water electrolysis technique is characterized in that it is a high temperature steam electrolysis (HTE, High Temperature Electrolysis).

More preferably, the nuclear load response power generation system includes a hydrogen tank for storing hydrogen (H ₂ ) separated through a water electrolysis device, and an oxygen tank for storing oxygen (O ₂ ) separated through the water electrolysis device It is characterized in that it further comprises.

More preferably, the solar thermal storage system comprises: a solar receiver for converting solar energy into solar thermal energy and transferring the converted solar thermal energy to the heat transfer fluid; a high-temperature tank for storing a heat transfer fluid in a high-temperature state that has absorbed solar heat while passing through the solar receiver; and a low-temperature tank for storing the low-temperature heat transfer fluid from which heat is taken away while passing through the heat exchanger. In addition, the solar thermal storage system is characterized in that it is installed in a solar thermal power plant or its adjacent area.

More preferably, the turbine power generation system comprises: a steam compressor for compressing the steam introduced from the secondary system of nuclear power generation; a combustor for burning oxygen injected from the oxygen tank and hydrogen injected from the hydrogen tank by using the vapor introduced from the vapor compressor as a catalyst; a steam turbine for converting the high-temperature/high-pressure working fluid output from the combustor into mechanical energy by applying an impulse or reaction force to the rotor blades while expanding; and a generator converting mechanical energy supplied from the steam turbine into electrical energy to generate electric power.

The effect of the nuclear load response power generation system according to embodiments of the present invention will be described as follows.

According to at least one of the embodiments of the present invention, by using solar energy to produce hydrogen from transient steam branched from the secondary system of nuclear power generation, and performing load-response power generation based on this, the effect on the primary system of the nuclear power generation There is an advantage in that the load response capability of the nuclear power plant can be greatly improved while minimizing the influence.

However, the effects that can be achieved by the nuclear load response power generation system according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are common in the technical field to which the present invention belongs from the description below. It can be clearly understood by those with the knowledge of

1 is a view showing the system structure of a typical nuclear power plant;
2A is an overall configuration diagram of a nuclear load response power generation system according to an embodiment of the present invention;
2B is a conceptual diagram illustrating a hydrogen production process of the water electrolysis device shown in FIG. 2A;
3 is a view showing a charging process of a nuclear load response power generation system according to an embodiment of the present invention;
4 is a view showing a discharge process of a nuclear load response power generation system according to an embodiment of the present invention.

In describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

On the other hand, when a component is referred to as "connected" or "connected" to another component in the present specification, it may be directly connected or connected to the other component, but other components in the middle It should be understood that there may be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly contacted" with another element, it should be understood that no other element is present in the middle. Other expressions for describing the relationship between elements, that is, expressions such as "between" and "immediately between" or "adjacent to" and "directly adjacent to", should be interpreted similarly.

In addition, the terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. As used herein, terms such as “comprises” or “have” are intended to designate the presence of an embodied feature, number, step, operation, component, part, or a combination thereof, one or more other features or numbers, It should be understood that the possibility of the presence or addition of steps, operations, components, parts or combinations thereof is not precluded in advance.

The present invention proposes a nuclear load response power generation system capable of improving the load response capability of a nuclear power plant when a load of a power system changes. In addition, the present invention uses the solar energy of the solar power plant to produce hydrogen from transient steam branched from the secondary system of nuclear power generation, and a nuclear load response power generation system capable of performing load response generation based on the produced hydrogen. suggest

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

2A is an overall configuration diagram of a nuclear load response power generation system according to an embodiment of the present invention, and FIG. 2B is a conceptual diagram illustrating a hydrogen production process of the water electrolysis device shown in FIG. 2A .

2A and 2B , the nuclear load response power generation system 100 according to an embodiment of the present invention includes a solar thermal storage system 110 , a heat exchanger 120 , a water electrolysis device 130 , and a hydrogen tank 140 . ), an oxygen tank 150 , a steam compressor 160 , a combustor 170 , a steam turbine 180 and a generator 190 . Here, the steam compressor 160 , the combustor 170 , the steam turbine 180 , and the generator 190 may be collectively referred to as a turbine power generation system.

On the other hand, although not shown in the drawing, the nuclear load response power generation system 100 may further include a control device that can control the overall operation of the devices 110 to 190 constituting the system 100. have.

The solar thermal storage system 110 may store solar thermal energy using a heat transfer fluid and provide the stored solar thermal energy to the heat exchanger 120 . In this case, the solar thermal storage system 110 may be installed in a solar thermal power plant or an area adjacent thereto. In addition, the solar thermal storage system 110 may be installed independently of the solar thermal power plant.

The solar thermal storage system 110 may include a solar receiver 111 , a high temperature tank 112 , a low temperature tank 113 , and a heat transfer fluid 114 .

The solar receiver 111 may convert solar energy collected through an optical facility (not shown) into solar thermal energy, and transfer the converted solar thermal energy to the heat transfer fluid 114 .

The high temperature tank 112 may store the heat transfer fluid 114 in a high temperature state that has absorbed solar heat while passing through the solar receiver 111 . The high temperature tank 112 may provide the heat transfer fluid 114 in a high temperature state to the heat exchanger 120 according to a control command of the controller.

The low-temperature tank 113 may store the low-temperature heat transfer fluid 114 from which heat is taken away while passing through the heat exchanger 120 . The low-temperature tank 113 may provide the low-temperature heat transfer fluid 114 to the solar receiver 111 according to a control command of the controller.

The heat transfer fluid 114 is used to perform heat exchange treatment with steam (H ₂ O) branched from the secondary system 50 of nuclear power while circulating the solar heat storage system 110 . As the heat transfer fluid, HITEC salt having excellent heat transfer efficiency and low cost may be used, but is not limited thereto.

The heat exchanger 120 is a heat transfer fluid 114 discharged from the steam (H ₂ O) branched from the secondary system 50 of nuclear power generation and the high temperature tank 112 of the solar thermal storage system 110, heat between Exchange processing can be performed. At this time, the temperature of the excess steam discharged from the secondary system 50 of the nuclear power plant may be approximately 200 ° C to 300 ° C, and the temperature of the heat transfer fluid discharged from the high temperature tank 112 is approximately 700 ° C to 800 ° C. can

That is, the heat exchanger 120 absorbs the heat of the heat transfer fluid 114 flowing in from the high-temperature tank 112, and transfers the absorbed heat to the steam flowing in from the secondary system 50 of nuclear power generation. . The heat transfer fluid 114 that has passed through the heat exchanger 120 moves to the low-temperature tank 113 of the solar thermal storage system 110 , and the vapor that has passed through the heat exchanger 120 moves to the water electrolysis device 130 . will do At this time, the temperature of the steam passing through the heat exchanger 120 may be about 700 °C to 800 °C.

The water electrolyzer 130 may separate the vapor that has passed through the heat exchanger 120 into oxygen (O ₂ ) and hydrogen (H ₂ ) using a predetermined water electrolysis technique. Here, the water electrolysis technique is a technique for separating oxygen (O ₂ ) and hydrogen (H ₂ ) by electrolyzing water (H ₂ O). As the water electrolysis technique, High Temperature Electrolysis (HTE), Proton Exchange Membrane (PEM), Alkaline Electrolysis (AE), etc. may be used, and more preferably, High-temperature steam electrolysis may be used.

High-temperature steam electrolysis is a method that uses the phenomenon that the electrical energy required to decompose water becomes lower at high temperatures. The application is called Solid Oxide Electrolyzer Cell (SOEC). That is, a method of electrolyzing water vapor at a high temperature of 750° C. or higher using stabilized zirconia or the like as an electrolyte of an oxygen ion conductor. Reaction formulas at the anode and cathode are as follows.

More specifically, as shown in Fig. 2b, the main components of high-temperature water electrolysis are composed of a dense ion-conducting electrolyte and two porous electrodes. When a potential difference occurs at the anode, water molecules react and split into hydrogen and oxygen. After that, hydrogen gas diffuses to the surface of the anode, and oxygen ions move to the anode through the electrolyte. The moved oxygen ions are oxidized to become oxygen and come out to the anode.

The transient steam branching from the secondary system 50 of nuclear power has about 68% of the energy for hot water electrolysis technology. Accordingly, the excess steam supplements the remaining 32% of energy through heat exchange with the heat transfer fluid 114 stored in the high temperature tank 112 of the solar thermal storage system 110 .

The water electrolysis device 130 may provide hydrogen separated from the high-temperature steam that has passed through the heat exchanger 120 to the hydrogen tank 140 , and may provide oxygen separated from the high-temperature steam to the oxygen tank 150 . have.

The hydrogen tank 140 may store hydrogen provided from the water electrolyzer 130 . The hydrogen tank 140 may provide hydrogen to the combustor 170 according to a control command of the controller.

The oxygen tank 150 may store oxygen provided from the water electrolyzer 130 . The oxygen tank 150 may provide oxygen to the combustor 170 according to a control command of the controller.

The steam compressor 160 may compress a working fluid (ie, steam) flowing from the secondary system 50 of nuclear power generation using mechanical energy provided from the steam turbine 180 . The high-temperature/high-pressure steam that has passed through the steam compressor 160 moves to the combustor 170 .

The steam compressor 160 is connected to the steam turbine 180 and a shaft (or a rotor) to rotate and drive. As the vapor compressor 160 , any one of an axial compressor and a centrifugal compressor may be used. The vapor compressor 160 may include one or more rotor blades that rotate to provide energy to the fluid and one or more stator blades that increase the pressure by decelerating the fluid.

The combustor 170 uses steam (H ₂ O) in a high temperature/high pressure state supplied from the vapor compressor 160 as a catalyst, and is injected from the hydrogen tank 140 and hydrogen (H ₂ ) and the oxygen tank 150 . Oxygen (O ₂ ) can be burned. At this time, hydrogen and oxygen may be supplied to the combustor 170 through a separate compressor (not shown). This is to increase the pressures of hydrogen and oxygen injected into the combustor 170 to be equal to or higher than the internal pressure of the combustor 170 .

In the combustor 170, water vapor (H ₂ O) is generated through a combustion reaction according to the following reaction equation.

The combustor 170 may heat steam (H ₂ O), which is a working fluid of the hydrogen power generation cycle, based on thermal energy generated through a combustion reaction between hydrogen (H ₂ ) and oxygen (O ₂ ).

The combustor 170 may output to the steam turbine 180 a working fluid in a high temperature/high pressure state including steam (H ₂ O) introduced from the steam compressor 160 and steam (H ₂ O), which is a combustion reaction product. have.

The steam turbine 180 may convert the high-temperature/high-pressure working fluid output from the combustor 170 into mechanical energy by applying an impulse or reaction force to the rotor blades while expanding.

The steam turbine 180, similar to the steam compressor 160, has two types, an axial flow type and a centrifugal type, and the use thereof is divided according to the power generation capacity. In one embodiment, the steam turbine 180 may be a multi-stage axial flow type, but is not necessarily limited thereto. The basic structure of a multi-stage axial flow turbine is composed of a stator blade that generates an incremental flow and a rotor blade that converts it into rotational energy.

Mechanical energy obtained through the steam turbine 180 is supplied as energy required to compress steam in the steam compressor 160 , and the rest is supplied as energy required to produce electricity in the generator 190 .

The generator 190 is connected to the steam turbine 180 and a shaft (or a rotor) to rotate and drive. The generator 190 may generate electricity by converting mechanical energy supplied from the steam turbine 180 into electrical energy. As the generator 190, any one of a DC generator and an AC generator may be used, and more preferably, an AC generator may be used.

As described above, the nuclear load response power generation system 100 according to an embodiment of the present invention uses solar thermal energy to produce hydrogen from the transient steam branched from the secondary system of nuclear power generation, and based on this, load response power generation By performing , it is possible to greatly improve the load response capability of the nuclear power plant while minimizing the impact on the primary system of the nuclear power plant.

On the other hand, the overall operation of the nuclear load response power generation system 100 is a charging process for producing and storing hydrogen based on the excess steam generated in the secondary system of nuclear power generation, and a load based on the hydrogen stored in the hydrogen tank. It consists of a discharging process that produces corresponding power.

3 is a diagram illustrating a charging process of a nuclear load response power generation system according to an embodiment of the present invention. 3, the heat transfer fluid 114 flowing in from the low-temperature tank 113 of the solar storage system 110 absorbs solar energy while passing through the solar receiver 111, and the solar receiver ( The heat transfer fluid passing through 111 moves to the high temperature tank 112 and is stored. The heat transfer fluid 114 stored in the high temperature tank 112 provides high temperature heat while passing through the heat exchanger 120 , and the heat transfer fluid passing through the heat exchanger 120 moves to the low temperature tank 113 . to be saved

The steam branched from the secondary system 50 of nuclear power generation passes through the heat exchanger 120 , receives high-temperature heat from the heat transfer fluid 114 , and then moves to the water electrolysis device 130 . The vapor introduced into the water electrolyzer 130 is decomposed into hydrogen and oxygen through an electrochemical reaction, the decomposed hydrogen moves to and is stored in the hydrogen tank 140 , and the decomposed oxygen is stored in the oxygen tank 150 . move to and save This series of operations is referred to as a charging process.

4 is a diagram illustrating a discharge process of a nuclear load response power generation system according to an embodiment of the present invention. As shown in FIG. 4 , the hydrogen discharged from the hydrogen tank 140 and the oxygen discharged from the oxygen tank 150 move to the combustor 170 . The steam branched from the secondary system 50 of nuclear power generation is compressed through the steam compressor 160 and moved to the combustor 170 . The hydrogen introduced into the combustor 170 is subjected to a combustion reaction with oxygen to generate water vapor, and the working fluid (ie, steam) introduced into the combustor 170 is a combustion reaction between hydrogen (H ₂ ) and oxygen (O ₂ ). It is converted into a high-temperature and high-pressure state based on the thermal energy generated through The working fluid output from the combustor 170 passes through the steam turbine 180 to produce additional power. This series of operations is referred to as a discharging process.

The charging and discharging processes of the nuclear load response power generation system 100 may be alternately performed according to the output variability of the renewable energy source on the power system.

For example, when the first event occurs, the nuclear load response power generation system 100 may perform a charging process of producing and storing hydrogen based on the surplus energy of the secondary system in connection with the secondary system of the nuclear power plant. . In this case, the first event may be an excess power supply event that occurs according to the output variability of the renewable energy source on the power system.

Meanwhile, when the second event occurs, the nuclear power generation system 100 may perform a discharge process for generating load-responsive power based on hydrogen stored in the hydrogen tank. In this case, the second event may be a power supply shortage event that occurs according to the output variability of the renewable energy source on the power system or an excessive power demand event that occurs according to the load variability of the consumer on the power system.

Meanwhile, although specific embodiments of the present invention have been described above, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, and should be defined by the following claims as well as the claims and equivalents.

100: nuclear load response power generation system 110: solar storage system
120: heat exchanger 130: water electrolyzer
140: hydrogen tank 150: oxygen tank
160: vapor compressor 170: combustor
180: steam turbine 190: generator

Claims (6)

a solar thermal storage system for storing solar thermal energy using a heat transfer fluid;
a heat exchanger for performing heat exchange between steam flowing in from a secondary system of nuclear power and a heat transfer fluid flowing in from the solar storage system;
a water electrolysis device for separating the vapor that has passed through the heat exchanger into oxygen (O ₂ ) and hydrogen (H ₂ ) using a predetermined water electrolysis technique; and
Nuclear power including a turbine power generation system for generating load-response power through a combustion reaction between steam introduced from the secondary system of the nuclear power plant, and oxygen (O ₂ ) and hydrogen (H ₂ ) separated through the water electrolyzer Load response power generation system. According to claim 1,
A hydrogen tank for storing hydrogen (H ₂ ) separated through the water electrolysis device; and
Nuclear load response power generation system further comprising an oxygen tank for storing oxygen (O ₂ ) separated through the water electrolysis device. According to claim 1, wherein the solar thermal storage system,
a solar receiver for converting solar energy into solar thermal energy and transferring the converted solar thermal energy to the heat transfer fluid;
a high-temperature tank for storing a heat transfer fluid in a high-temperature state that has absorbed solar heat while passing through the solar receiver; and
and a low-temperature tank for storing a low-temperature heat transfer fluid from which heat has been lost while passing through the heat exchanger. The nuclear load response power generation system according to claim 1, wherein the solar thermal storage system is installed in a solar thermal power plant or an area adjacent thereto. According to claim 1,
The predetermined water electrolysis technology is a nuclear load response power generation system, characterized in that the high temperature steam electrolysis (HTE, High Temperature Electrolysis). According to claim 2, The turbine power generation system,
a vapor compressor for compressing the vapor introduced from the secondary system of the nuclear power plant;
a combustor for burning oxygen injected from the oxygen tank and hydrogen injected from the hydrogen tank by using the vapor introduced from the vapor compressor as a catalyst;
a steam turbine for converting the high-temperature/high-pressure working fluid output from the combustor into mechanical energy by applying an impulse or reaction force to the rotor blades while expanding; and
and a generator that converts mechanical energy supplied from the steam turbine into electrical energy to generate electric power.

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