RU2805457C1 - Double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit - Google Patents

Abstract

FIELD: nuclear energy.

SUBSTANCE: invention is related to a double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit. In reactor core 1, the released nuclear fission energy is transferred to the hydrogen-containing working fluid of liquid circuit 2, diathermic oil, circulating through liquid circuit 2 due to the operation of circulation pump 3. The hot diathermic oil of liquid circuit 2 transfers thermal energy to the working fluid of steam circuit 5 with the working fluid pentane. From steam generator 6 of steam circuit 5, superheated pentane steam under high pressure enters steam turbine 7 with electric generator 8 on the same shaft. Due to rotation of turbine 7 in electric generator 8, electrical energy is generated. Passing steam turbine 7, pentane vapor reduces the pressure and enters condenser 9, where it is condensed due to cooling by the cooling medium of cooling system 11. Then liquid pentane is supplied again to steam generator 6 using liquid supply pump 10. Unified cooling system 11 with control valves 12 and 13 provides an independent supply of cooling medium through condenser 9 of steam circuit 5 and heat exchanger-cooler 4 of liquid circuit 2 of the nuclear power system.

EFFECT: increase of efficiency and reliability of the nuclear energy system, reduction of the accident rate of the nuclear reactor, the weight and size characteristics of the nuclear reactor and the pipelines of the liquid circuit of the nuclear energy system.

2 cl, 1 dwg

Description

The invention relates to energy and can be used to create power plants with nuclear reactors.

There is a known method of operating a nuclear reactor with an organic coolant of the ARBUS installation (Arctic block plant), which involves organizing the pumping of an organic hydrogen-containing coolant in a closed loop through the core of a nuclear reactor, bringing the reactor to power and operating at power with removal of the generated energy by a closed-loop coolant (Aleksenko Yu N., Gavrilin A.I., Gataullin N.G., etc. Experience in operating the ARBUS reactor plant // Collection of reports of the seminar “Prospects for the use of nuclear reactors for heat supply of cities and industrial enterprises”, Dimitrovgrad, RIAR, 1978, pp. 24-44). Organic hydrogen-containing coolants include liquids containing carbon and hydrogen in their structure.

Various types of organic liquid, hydrostabilized gas oil, hydroterfinyl, etc. are used as an organic hydrogen-containing coolant in a closed reactor circuit.

The use of hydrogen-containing organic liquids as coolants in nuclear reactors is based on the fact that these liquids have a number of advantages over other types of coolants. In particular:

- low coolant activation allows servicing the coolant circuit even during reactor operation;

- the high boiling point of the organic coolant at atmospheric pressure makes it possible to avoid its boiling in the event of an accidental loss of pressure in the circuit;

- low operating pressure in a closed circuit significantly reduces the likelihood of rupture of equipment and pipelines;

- the corrosive passivity of the coolant to structural materials allows the use of cheap aluminum alloys and carbon steels as the latter, and the use of serial oil equipment and fittings as part of the primary circuit without imposing special requirements on them;

- the comparative simplicity of maintenance, repair and control of the reactor makes it possible to automate the installation as much as possible, reduce the requirements for the qualifications of operating personnel and limit their number.

All together, this provides unique opportunities to ensure nuclear and radiation safety, ease of operation and reduction of capital costs for construction, which is especially attractive when used in remote areas.

There is a known method of operating a nuclear reactor with an organic hydrogen-containing coolant of the ATU-15×2 installation,

providing for cooling of the core due to the circulation of an organic coolant (ditolylmethane) in a closed loop (Tokarev Yu.I., Tsykanov V.A., Ryumin V.P. and others. ATU-15×2 - nuclear heat supply station for remote areas. / / Questions of atomic science and technology. Series. Physics and technology of nuclear reactors. 1978. Issue 1/21, part 1, pp. 112-116).

The disadvantage of this technical solution is the use of ditolylmethane as an organic hydrogen-containing coolant in a closed loop reactor, whose molecules under the influence of prolonged ionizing radiation and temperature can disintegrate, forming light, medium and heavy fractions. The latter, interacting with each other, form super-heavy molecules that are deposited on heat transfer surfaces in the form of deposits (fowling effect), which leads to deterioration in the cooling of fuel rods, their cleaning and requires replacement of the coolant.

It is known that in recent years new types of organic hydrogen-containing liquids have appeared in operation - diathermic oils (heat-transfer oils), which are ordinary petroleum distillate oils of selective purification - this is a product of deep oil refining followed by distillation, which have low corrosiveness and the ability to cause the formation various deposits inside the circulation system. Currently, both Russian and imported hydrogen-containing diathermic oils (heat-transfer oils), for example, LUKOIL TERMO OIL, Mobiltherm, ShellHeatTransferoilS2, Bashneft AMT-300, Gazpromneft MT-300, etc. are presented on the domestic market. Temperature range of use of various diathermic oils as coolants varies from -115°C to 410°C. Heat-transfer oils are used in closed circulation systems (V.I. Stakhiv. Review and comparative characteristics of heat-transfer oils used in Russia / V.I. Stakhiv, L.N. Bagdasarov, V.I. Stakhiv // Young scientist. - 2016 - No. 2 (106). - P.73-76).

The use of organic hydrogen-containing liquid diathermic oil as a coolant for supplying thermal energy in various technological processes in industry is preferable to steam heating, as it allows one to obtain high temperatures at low pressures, which reduces the cost of basic equipment. Due to the high flexibility of such systems, many industrial technologies developed in the last decade (production of polyester resins, synthetic resins, thermoplastic materials, etc.) use oil at temperatures up to 340°C.

A known device is an energy system based on an organic Rankine cycle installation, which includes an oil boiler, a liquid circuit with an intermediate coolant connecting the boiler and an installation based on an organic Rankine cycle, which is a closed steam circuit with an organic hydrogen-containing working fluid containing a turbine on a shaft with an electric generator , evaporator, condenser, heat exchanger-recuperator, pump and cooling system of the installation based on the organic Rankine cycle (Sobol V.A. Mini-CHP in Rechitsa: advanced technologies in the use of local fuels // Energy Strategy Magazine, No. 2( 20), 2011, pp. 57-59). Various types of hydrogen-containing substances, for example, pentane, can be used as the working fluid of a power plant.

The advantage of a plant based on the organic Rankine cycle is its ability to operate from any source of thermal energy, for example, combustion of traditional fuels, solar energy, and nuclear energy.

A known energy system is based on an organic Rankine cycle installation, which is a closed steam circuit with an organic working fluid containing a turbine on a shaft with an electric generator and a cooling system with a heat exchanger and a circulation pump, while the system is equipped with a source of thermal energy for heating the working fluid of the organic Rankine cycle installation for the combustion of associated gas (RF Patent No. 2573541, published on January 20, 2016, Bulletin No. 2).

However, this technical solution cannot be applied when using a nuclear reactor as a source of thermal energy.

It is known that water (hydrogen oxide) has the formula H ₂ O and is the simplest stable compound of hydrogen and oxygen. Water is an inorganic hydrogen-containing substance because it is a binary inorganic compound, the molecule of which consists of two hydrogen atoms and one oxygen atom, which are connected by a covalent bond. Water is the only substance that exists in three states of aggregation: solid, liquid and gaseous (Water chemistry: Analytical support for laboratory workshop: textbook / V.I. Aksenov, L.I. Ushakova, I.I. Nichkova; [ under the general editorship of V.I. Aksenov]; Ministry of Education and Science of the Russian Federation, Ural, Federal University - Ekaterinburg: Ural Publishing House, University, 2014. - P. 5-6 ).

However, water is not an organic hydrogen-containing liquid because it does not contain carbon atoms in its structure.

It is known that in nuclear power plants with double-circuit water-cooled reactors of the VVER type, which include an interconnected reactor, liquid and steam circuits, while the working fluid of the liquid circuit passes through the reactor and is intended for reliable and constant cooling of the core reactor, water under high pressure is used, and as the working fluid of the steam circuit, water and steam produced by the heat obtained in the reactor and used in the steam turbine to produce electricity (RF Patent No. 2742730, published on 02/10/2021, Bulletin No. 4).

A disadvantage of water-cooled nuclear reactors of the VVER type (reactors with pressurized water) is the operation of the steam circuit (steam-producing plant) when the liquid circuit coolant in the form of high-pressure water is pumped through its steam generators, which imposes special requirements on the design and operation of the liquid circuit for the operation of vessels under pressure. high pressure.

It is known that the main disadvantage of nuclear power plants based on pressurized water reactors (pressurized water reactors) with steam turbine units is the low steam parameters of the steam circuit at the outlet of the steam generators: pressure about 3.0-3.7 MPa and temperature 285- 300°C, which is caused by limiting the temperature of the coolant of the liquid circuit - water to maintain it in the liquid phase. As a result, the efficiency of such installations is about 20%. Due to the low initial steam parameters of the steam circuit, the flow part of the steam turbine operates in the wet steam region. In addition to the low cycle efficiency, at low initial steam parameters, due to high humidity, the internal efficiency decreases and intense drop-impact erosion of turbine unit blades occurs (RF Patent No. 2757737, published on October 21, 2021, Bulletin No. 30).

To eliminate these disadvantages, it is necessary to use intermediate separation and intermediate superheating of steam, which leads to a significant reduction in the design of nuclear power plants based on pressurized water reactors and requires the use of additional volumetric equipment.

A two-circuit nuclear energy system with hydrogen-containing working fluids in each circuit is known, containing a water-cooled nuclear reactor, a liquid (first) circuit with a circulation pump and a hydrogen-containing working fluid in the form of water under high pressure, the state of aggregation of which does not change during operation, steam ( second) a circuit with a hydrogen-containing working fluid in the form of water, the state of aggregation of which changes during operation, including a steam generator, a steam turbine with an electric generator on the same shaft, a condenser and a liquid supply pump, while the liquid circuit passes through a nuclear reactor and a steam generator of the steam circuit (A A. Simonova, M. A. Bezgin, K. S. Ulyamaev, A. V. Levin // Young scientist. - 2018. - No. 35 (221). - P. 5-7). The hydrogen-containing coolant (high-pressure water) of the liquid (first) circuit takes heat from the reactor core and transfers it in the steam generator to the hydrogen-containing working substance (water) of the steam (second) circuit, while the working fluid of the steam circuit turns into a state of steam, and the steam of this circuit used to operate a steam turbine.

The disadvantages of this technical solution are the need to create high water pressure in the liquid circuit, which removes heat from the reactor core, to prevent water vaporization in the reactor core, which leads to an increase in the weight and size characteristics of the nuclear reactor and liquid circuit pipelines and an increased likelihood of destruction of the liquid circuit pipelines, the absence of a cooling system for the liquid circuit of a power plant in the event of a steam circuit failure, which can lead to the creation of an emergency situation with the cooling of a nuclear reactor, while the use of water in the steam circuit leads to intense corrosion of the steam turbine blades and low efficiency due to low steam pressure at exit from the steam generator.

The technical result that can be obtained by implementing the invention is to increase the efficiency and reliability of the nuclear energy system, reduce the accident rate of the nuclear reactor, the weight and size characteristics of the nuclear reactor and the pipelines of the liquid circuit of the nuclear energy system.

To implement this technical result, a double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit, including a nuclear reactor, a liquid circuit with a circulation pump and a hydrogen-containing working fluid, the aggregate state of which does not change during operation, a steam circuit with a hydrogen-containing working fluid, an aggregate the state of which changes during operation, containing a steam generator, a steam turbine with an electric generator on the same shaft, a condenser and a supply liquid pump, while the liquid circuit passes through a nuclear reactor and a steam generator of the steam circuit, is equipped with an organic hydrogen-containing liquid as a hydrogen-containing working fluid of the liquid circuit, an organic a hydrogen-containing substance as a hydrogen-containing working fluid of the steam circuit, a heat exchanger-cooler located in the liquid circuit of the nuclear power system, a single cooling system with control valves that allow for an independent supply of cooling medium through the steam circuit condenser and the heat exchanger-cooler of the liquid circuit.

An organic hydrogen-containing liquid in the form of diathermic oil is used as the hydrogen-containing working fluid of the liquid circuit.

An organic hydrogen-containing substance in the form of pentane is used as the hydrogen-containing working fluid of the steam circuit.

Water is used as the cooling medium of the unified cooling system.

Introduction into the composition of a double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit, a hydrogen-containing organic liquid in the form of diathermic oil, as a hydrogen-containing working fluid of a liquid circuit, an organic hydrogen-containing substance as a hydrogen-containing working fluid of a steam circuit, a heat exchanger-cooler placed in a liquid circuit circuit of a nuclear power system, a cooling system with control valves, which allows for parallel and independent supply of a cooling medium through a steam circuit condenser and a liquid circuit heat exchanger-cooler, makes it possible to obtain a new property, which consists in the possibility of reducing pressure in the nuclear reactor and the liquid circuit of the power system, increasing temperature of the working fluid of the liquid circuit (without steam formation) of the working fluid in the reactor core, and, accordingly, an increase in steam pressure in the steam circuit when it leaves the steam generator, due to the replacement of the working fluid of the liquid circuit from the use of water (inorganic hydrogen-containing liquid) to the use of organic hydrogen-containing liquid, in the form of diathermic oil, which ensures increased efficiency and reliability of the nuclear energy system and a reduction in the weight and size characteristics of the nuclear reactor and pipelines of the liquid circuit of the energy system, as well as a reduction in the accident rate of the nuclear reactor due to the use of organic matter in the steam circuit of the nuclear energy system hydrogen-containing substance pentane instead of water, which leads to reduced corrosion and destruction of steam turbine blades, and a single cooling system with control valves that allow for an independent supply of cooling medium through the steam circuit condenser and the liquid circuit heat exchanger-cooler, which eliminates the possibility of creating an emergency situation with cooling nuclear reactor when the steam circuit fails.

In fig. Figure 1 shows a schematic diagram of a double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit.

A double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit includes a nuclear reactor 1, a liquid (first) circuit 2 with a circulation pump 3 and a heat exchanger-cooler 4. As a hydrogen-containing working fluid of the liquid circuit 2 of the energy system, a hydrogen-containing organic liquid is used in the form diathermic oil, the state of aggregation of which does not change during operation.

The double-circuit nuclear energy system also includes a steam (second) circuit 5, containing a steam generator 6, a steam turbine 7 with an electric generator 8 on the same shaft, a capacitor 9 and a liquid supply pump 10. An organic hydrogen-containing substance is used as the hydrogen-containing working fluid of the steam circuit 5 in the form of pentane, the state of aggregation of which changes during operation.

The liquid circuit 2 of the energy system passes through the nuclear reactor 1 and the steam generator 6 of the steam circuit 5.

The double-circuit nuclear energy system also includes a single cooling system 11 with control valves 12 and 13, which allows for an independent supply of cooling medium through the condenser 9 of the steam circuit 5 and the heat exchanger-cooler 4 of the liquid circuit 2 of the energy system. Water can be used as the cooling medium for the cooling system.

The operation of the proposed double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit is carried out as follows.

In nuclear reactor 1, thermal energy is released due to the fission reaction of nuclear fuel. Thermal energy in the reactor core 1 is transferred to the hydrogen-containing working fluid of liquid circuit 2, diathermic oil, which circulates through circuit 2 due to the operation of circulation pump 3. Modern hydrogen-containing diathermic oils (coolant oils), for example, LUKOIL TERMO OIL, Mobiltherm, ShellHeatTransferoilS2, Bashneft AMT-300, Gazpromneft MT-300, etc., have a heating temperature level of up to 410 ° C without boiling, that is, without changing the state of aggregation and phase transition to steam. This allows diathermic oil to be heated to high temperatures without increasing the pressure in circuit 2, which makes it possible to significantly reduce the weight and size characteristics of the nuclear reactor and the pipelines of the liquid circuit of the power plant, in contrast to the prototype, which uses high-pressure water to prevent water vaporization in the reactor core. In this case, the organic hydrogen-containing liquid in the form of diathermic oil does not change its state of aggregation during the operation of the energy system and constantly remains in a liquid state.

The hot diathermic oil of the liquid circuit 2 transfers thermal energy to the working fluid of the steam circuit 5 of the energy system in the steam generator 6. After heat transfer, the cooled diathermic oil of the liquid circuit 2 again enters the nuclear reactor 1 using the circulation pump 3.

The hot diathermic oil of the liquid circuit 2 transfers thermal energy to the working fluid of the steam circuit 5 of the energy system with the working fluid pentane. The transfer of thermal energy occurs in the steam generator 6, where liquid pentane is heated due to thermal energy, turns into steam, and the pentane steam is superheated to high temperature and pressure. This makes it possible to increase the pressure of pentane vapor in the steam circuit 5 when it leaves the steam generator 6, which causes an increase in the thermodynamic efficiency of the steam circuit 5, and, accordingly, the efficiency of the energy system as a whole.

From the steam generator 6 of the steam circuit 5, superheated pentane steam under high pressure enters the steam turbine 7 with an electric generator 8 on the same shaft. Due to the rotation of the turbine 7 in the electric generator 8, useful electrical energy is generated for consumers (not shown in the figure).

The use of steam circuit 5 of a nuclear energy system, with a hydrogen-containing working fluid in the form of an organic hydrogen-containing substance pentane, instead of water, makes it possible to reduce corrosion of the blades of the steam turbine 7 and reduce the accident rate of the nuclear reactor 1.

Passing the steam turbine 7, the pentane vapor reduces the pressure and enters the condenser 9, where it is condensed due to cooling from the cooling medium of the cooling system 11. Then the liquid pentane is supplied again to the steam generator 6 using the liquid supply pump 10.

Accordingly, the hydrogen-containing working fluid of steam circuit 5 in the form of pentane changes its state of aggregation twice in one revolution along circuit 5.

A single cooling system 11 with control valves 12 and 13 allows for an independent supply of cooling medium through the condenser 9 of the steam circuit 5 and the heat exchanger-cooler 4 of the liquid circuit 2 of the energy system. Water can be used as the cooling medium for the cooling system.

During normal operation of the nuclear energy system, the control valve 13 of the unified cooling system 11 is closed, the control valve 12 is open and cooling water flows only into the condenser 9 for heat exchange and condensation of pentane steam of the steam circuit 5, ensuring its stable operation and the generation of electricity in the electric generator 8.

In the event of an emergency of the steam circuit 5, the control valve 12 closes, the control valve 13 of the cooling system 11 opens and cooling water flows only into the heat exchanger-cooler 4 of the liquid circuit 2 for heat exchange and cooling of the diathermic oil of circuit 2. This eliminates the possibility of creating an emergency with the cooling of a nuclear reactor 1 in case of failure of steam circuit equipment 2.

Sources of information taken into account when preparing the application:

1. Aleksenko Yu.N., Gavrilin A.I., Gataullin N.G. and others. Experience in operating the ARBUS reactor plant. // Sat. report seminar “Prospects for the use of nuclear reactors for heat supply to cities and industrial enterprises.” Dimitrovgrad, RIAR, 1978, p. 24-44.

2. Tokarev Yu.I., Tsykanov V.A., Ryumin V.P. etc. ATU-15×2 - nuclear heat supply station for remote areas. // Issues of atomic science and technology. Ser. Physics and technology of nuclear reactors. 1978. Vol. 1/21, part 1, pp. 112-116.

3. Stakhiv V.I. Review and comparative characteristics of heat transfer oils used in Russia / V.I. Stakhiv, L.N. Bagdasarov, V.I. Stakhiv // Young scientist. - 2016. - No. 2 (106). - pp. 73-76.

4. Sobol V.A. Mini-CHP in Rechitsa: advanced technologies in the field of using local fuels // Energy Strategy Magazine, No. 2(20), 2011, p. 57-59.

5. RF Patent No. 2573541, publ. dated January 20, 2016, Bulletin. No. 2.

6. Water chemistry: Analytical support for laboratory workshop: textbook. allowance / V.I. Aksenov, L.I. Ushakova, I.I. Nichkova; [under general ed. IN AND. Aksenova]; Ministry of Education and Science of Russia. Federation, Ural, federal. univ. - Ekaterinburg: Ural Publishing House, University, 2014. - P. 5-6.

7. RF Patent No. 2742730, publ. dated 02/10/2021, Bulletin. No. 4.

8. RF Patent No. 2757737, publ. dated 10/21/2021, Bulletin. No. 30.

9. A.A. Simonova, M.A. Bezgin, K.S. Ulyamaev, A.V. Levin // Young scientist. - 2018. - No. 35 (221). - P. 5-7 - prototype.

Claims (2)

1. Double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit, including a nuclear reactor, a liquid circuit with a circulation pump and a hydrogen-containing working fluid, the state of aggregation of which does not change during operation, a steam circuit with a hydrogen-containing working fluid, the state of aggregation of which does not change the process of operation changes, containing a steam generator, a steam turbine with an electric generator on the same shaft, a condenser and a liquid supply pump, while the liquid circuit passes through a nuclear reactor and a steam generator of a steam circuit, characterized in that it is equipped with an organic hydrogen-containing liquid in the form of diathermic oil as a hydrogen-containing working bodies of the liquid circuit, an organic hydrogen-containing substance as a hydrogen-containing working fluid of the steam circuit, an organic hydrogen-containing substance in the form of pentane as a hydrogen-containing working fluid of the steam circuit, a heat exchanger-cooler located in the liquid circuit of the nuclear energy system, a unified cooling system with control valves that allow independent supply of cooling medium through the steam circuit condenser and the liquid circuit heat exchanger-cooler. 2. A double-circuit nuclear energy system with hydrogen-containing working fluids in each circuit according to claim 1, characterized in that water is used as the cooling medium of the unified cooling system.

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