RU2805458C1 - Nuclear power unit for nuclear-powered ships - Google Patents

Abstract

FIELD: nuclear power unit for nuclear-powered ships.

SUBSTANCE: in the nuclear reactor (2), thermal energy is generated, which is converted through the liquid circuit (3) and the steam circuit (5) into high pressure pentane vapor, discharged in the steam turbine (7), which ensures rotation of the electric generator (8) and generation of useful electrical energy for the propulsion motors (14) and other electrical consumers (15) of the nuclear-powered ship, connected to the electric generator (8). The hot water of the closed cooling circuit (16), obtained by cooling the steam as the cooling circuit (16) passes through the condenser (9), is collected in the expansion tank (17), and then, using the circulation pump (18), is supplied to the heat exchanger/heater (19) to transfer part of the high-temperature thermal energy to the circuit (21) of thermal energy consumers (22) of nuclear-powered ships. After transferring part of the thermal energy in the heat exchanger/heater (19), the coolant of the closed cooling circuit (16) is supplied to the heat exchanger/cooler (20), where warm water is cooled due to heat exchange with sea water supplied through the sea cooling water line (23) using a circulation pump (24).

EFFECT: increase of reliability and efficiency of the steam turbine, as well as increase of energy efficiency and efficiency of power control of a nuclear power unit.

1 cl, 1 dwg

Description

The invention relates to the field of ship nuclear power and can be used in the construction of nuclear icebreakers, nuclear submarines, civilian ships and military ships with nuclear power plants, floating nuclear thermal power plants, etc.

There is a known method for controlling a nuclear power plant, which consists in monitoring changes in the external load by a turbine control system using a control valve that changes the steam flow to the turbine based on a signal to maintain the turbine speed, and regulating the steam pressure by changing the position of the steam generator feedwater valve based on a signal that the steam pressure deviates from given value (Yurkevich G.P. "Control systems for nuclear reactors. Principles of operation and creation", M., 2009, p. 331, Fig. 5.12).

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, high-pressure water is used, and the working fluid of the steam circuit is water and steam produced by the heat generated in the reactor and used in a steam turbine to produce electricity (RF Patent No. 2742730, published on 02/10/2021, Bull. 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. 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 double-circuit nuclear power plants using water as working fluids, and requires the use of additional volumetric equipment.

It is known that the main disadvantage of double-circuit nuclear power plants with water steam turbine units is the low steam parameters of the steam (second) circuit at the outlet of the steam generators: pressure about 3.0-3.7 MPa and temperature 285-300°C. Due to the low initial steam parameters in the steam circuit, the flow part of the steam turbine operates in the wet steam region. In this regard, at low initial steam parameters due to high humidity, intense drop-impact erosion of turbine unit blades occurs (RF Patent No. 2757737, published on October 21, 2021, Bulletin No. 30).

The disadvantage of this technical solution is that in order to eliminate drop-impact erosion of turbine unit blades, additional circuit equipment, significant in terms of weight, size and complexity, is used, consisting of a circulation system, which includes a circulation pump, a water steam superheater and an additional heat exchanger for heating water connected in a closed circuit. an additional circuit, located in at least one steam generator, and heated water of the primary circuit to a temperature not lower than the temperature of the superheated steam.

A nuclear power plant for nuclear-powered ships is known, consisting of a nuclear reactor located inside the hull of a nuclear-powered ship and two closed circuits, the first of which is a liquid circuit with a circulation pump, and the second, a steam circuit, including a steam generator, a steam turbine with an electric generator on the same shaft, and a condenser and a liquid pump, wherein the liquid circuit passes through the nuclear reactor and the steam generator of the steam circuit, the electric generator is connected to the propeller electric motors and other electrical consumers of the nuclear-powered ship, and the steam circuit is equipped with a bypass line for maneuvering the steam turbine, containing a pickling control valve and a throttling device and connecting sections of the steam circuit after the steam generator and before the condenser, bypassing the turbine (Energy of nuclear ships / A.N. Dyadik, S.N. Surin. - St. Petersburg: Shipbuilding, 2014. - 477 pp., pp. 165-170).

The main disadvantages of this technical solution are the use of water as the working fluid of the second (steam) circuit of the power plant and, as a consequence, the high corrosiveness of water vapor in the steam circuit, leading to corrosion of the steam turbine blades, low energy efficiency of the power plant due to the lack of use of thermal energy, obtained by cooling steam in the condenser of the steam circuit, and discharging it into the environment.

The technical result that can be obtained by implementing the present invention is the possibility of increasing the reliability and efficiency of a steam turbine by replacing water as the working fluid of the steam circuit with an organic working fluid (for example, pentane) and reducing corrosion of steam turbine blades, increasing energy efficiency and efficiency of managing the power of a nuclear power plant through the use of thermal energy obtained by cooling steam for internal consumers of thermal energy of the nuclear-powered ship.

To achieve this technical result, the proposed nuclear power plant for nuclear-powered ships, consisting of a nuclear reactor located inside the hull of a nuclear-powered ship and two closed circuits, the first of which is a liquid circuit with a circulation pump, and the second, a steam circuit, including a steam generator, a steam turbine with an electric generator on one shaft, a capacitor and a liquid pump, while the liquid circuit passes through the nuclear reactor and the steam generator of the steam circuit, the electric generator is connected to the propeller motors and other electrical consumers of the nuclear-powered ship, and the steam circuit is equipped with a bypass line for maneuvering the steam turbine, containing a pickling control valve and a throttling device and connecting sections of the steam circuit after the steam generator and in front of the condenser, bypassing the turbine, is equipped as a working fluid of the steam circuit with an organic working fluid, a closed cooling circuit passing through the condenser of the steam circuit and containing an expansion tank, a circulation pump, a heat exchanger-heater through which the circuit passes consumers of thermal energy of the nuclear-powered ship, and a heat exchanger-cooler, through which the sea cooling water line with a circulation pump passes.

An organic working fluid in the form of pentane is used as the working fluid of the steam circuit.

Introduction into the composition of a nuclear power plant for nuclear powered ships as a working fluid of the steam circuit of an organic working fluid (for example, pentane), a closed cooling circuit passing through the steam circuit condenser and containing an expansion tank, a circulation pump, a heat exchanger-heater through which the thermal consumer circuit passes energy of the nuclear-powered ship, and the heat exchanger-cooler, through which the sea cooling water line with the circulation pump passes, allows us to obtain a new property, which consists in the possibility of reducing corrosion of steam turbine blades and increasing the reliability of the shunting turbine by replacing water as the working fluid of the steam circuit with an organic working fluid body (for example, pentane), which eliminates the operation of the flow part of a steam turbine in the area of wet steam, increasing the energy efficiency of a nuclear power plant through the use of waste thermal energy (obtained from nuclear energy) for internal consumers of thermal energy of the nuclear-powered ship, which is ensured by the collection of hot water in expansion capacity obtained by cooling steam when passing a closed cooling circuit through the condenser of the steam circuit, and transferring part of this thermal energy in the heat exchanger-heater from the hot water of the closed cooling circuit to the coolant of the thermal energy consumer circuit of the nuclear-powered ship, as well as increasing the efficiency of power control of the power plant through regulation increasing or decreasing the flow rate of water supply from the expansion tank of a closed cooling circuit during bypassing (maneuvering) of the steam turbine (diversion of part of the steam flow bypassing the steam turbine and subsequent return to the steam circuit).

In fig. Figure 1 shows a schematic diagram of a nuclear power plant for nuclear-powered ships, where:

1 - hull of a nuclear-powered ship (nuclear-powered icebreaker, nuclear-powered submarine, civilian ship or warship with a nuclear power plant);

2 - nuclear reactor;

3 - liquid circuit;

4 - liquid circuit circulation pump;

5 - steam circuit;

6 - steam generator;

7 - steam turbine;

8 - electric generator;

9 - steam circuit condenser;

10 - circulation pump of the steam circuit;

11 - bypass line for maneuvering the steam turbine;

12 - bypass line etching control valve;

13 - bypass line throttle device;

14 - rowing electric motors;

15 - other power consumers of the nuclear-powered ship;

16 - closed circuit of the cooling system;

17 - expansion tank of a closed cooling circuit;

18 - circulation pump of a closed cooling circuit;

19 - heat exchanger-heater of a closed cooling circuit;

20 - heat exchanger-cooler of a closed cooling circuit;

21 - circuit of consumers of thermal energy of the nuclear-powered ship;

22 - consumers of thermal energy of the nuclear-powered ship;

23 - sea cooling water line.

24 - circulation pump of the sea cooling water line.

The proposed nuclear power plant for nuclear-powered ships operates as follows.

To operate the proposed nuclear power plant for nuclear-powered ships, a double-circuit nuclear installation is used, consisting of a nuclear reactor 2, a liquid circuit 3 and a steam circuit 5, located inside the hull of the nuclear-powered ship 1.

In nuclear reactor 2, due to the fission reaction of nuclear fuel, thermal energy is released and transferred to the working fluid of the liquid circuit 3, which leads to heating of the working fluid to a high temperature. The circulation of the working fluid of circuit 3 is ensured by the operation of the circulation pump 4. In this case, the working fluid of circuit 3 does not change its state of aggregation during circulation through circuit 3 and constantly remains in a liquid state.

The working fluid of circuit 3, heated to a high temperature, transfers thermal energy to the working fluid of steam circuit 5 in the steam generator 6. After heat transfer, the cooled working fluid of circuit 3 again enters the nuclear reactor 2 using circulation pump 4.

When transferring thermal energy in the steam generator 6, the working fluid of the steam circuit 5, which uses an organic working fluid (for example, pentane), is heated due to thermal energy and turns into steam, which is overheated to high temperature and pressure. From steam generator 6 of circuit 5, superheated steam of the organic working fluid under high pressure enters steam turbine 7 with 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 the propulsion electric motors 14 and other electrical consumers 15 of the nuclear-powered ship connected to the electric generator 8.

The use of an organic working fluid as the working fluid of circuit 5 makes it possible to reduce the weight and size characteristics of the steam turbine 7 and reduce the corrosion of the blades of the steam turbine 7.

Passing the steam turbine 7, the vapors of the organic working fluid reduce the pressure and enter the condenser 9 of the steam circuit 5, where they are condensed due to cooling from the cooling medium supplied through the closed cooling circuit 16.

Then, from the condenser 9, the condensed organic working fluid (pentane) of the steam circuit 5 is again supplied to the steam generator 6 using the circulation pump 10.

If there is a need for a sharp load shedding and the need to reduce the power of turbine 7, which occurs when a nuclear-powered ship (for example, a nuclear-powered icebreaker or a warship with a nuclear power plant) is completely stopped or slowed down in heavy ice or other maneuvers, and then the need for subsequent re-acceleration, excess The steam generated by the steam generator 6 was discharged using the bypass line 11 directly into the condenser 9, bypassing the turbine 7. This ensures maneuvering of the turbine 7 by opening the pickling control valve 12 and passing the steam through the throttling device 13 of the bypass line 11, bypassing the turbine 7.

Increasing the energy efficiency of a nuclear power plant occurs through the use of waste thermal energy (obtained from nuclear energy) for internal consumers of thermal energy 22 nuclear-powered ships.

To do this, the hot water of the closed cooling circuit 16, obtained by cooling the steam as the cooling circuit 16 passes through the condenser 9 of the steam circuit 5, is collected in the expansion tank 17 of the cooling circuit 16, and then, using a circulation pump 18, is supplied to the heat exchanger-heater 19 of the closed cooling circuit 16 for transferring part of the high-temperature thermal energy to circuit 21 of thermal energy consumers of 22 nuclear-powered icebreakers due to the heat exchange of hot water of cooling circuit 16 and coolant of circuit 21 of thermal energy consumers of 22 nuclear-powered icebreakers.

After transferring part of the thermal energy in the heat exchanger-heater 19, the coolant (warm water) of the closed cooling circuit 16 is supplied to the heat exchanger-cooler 20, where the warm water is cooled to ambient temperature due to heat exchange with sea water supplied through the sea cooling water line 23 using circulation pump 24.

Then, the water of the closed cooling circuit 16, cooled to ambient temperature, is again supplied to the condenser 9 of the steam circuit 5 using the circulation pump 18 for heat exchange, cooling and condensation of vapors of the organic working fluid (pentane) of the steam circuit 5.

In this case, the cooling circuit 16 is closed, which makes it possible to create a closed cooling circuit 16 to ensure the operation of the steam circuit 5 and the transfer of thermal energy from the nuclear power plant, initially to consumers of thermal energy 22 of the nuclear-powered ship, and then to the environment (sea water).

It should be noted that in order to increase the efficiency of power control of the power plant (simultaneously using the bypass line 11 to regulate the volume of steam supplied to the turbine 7) by regulating the volume of supplied water, the use of expansion tank 17 makes it possible to increase or decrease the water supply flow of a closed cooling circuit 16 when bypassing the shunting turbine 7 (removing part of the steam flow bypassing the steam turbine 7 with subsequent return to the steam circuit 5).

Sources of information taken into account when preparing the application:

1. Yurkevich G.P. "Nuclear reactor control systems. Principles of operation and creation", M., 2009, p. 331, fig. 5.12.

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

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

4. Energy of nuclear ships / A.N. Dyadik, S.N. Surin. - St. Petersburg: Shipbuilding, 2014. - 477 pp., pp. 165-170 - prototype.

Claims (1)

A nuclear power plant for nuclear-powered ships, consisting of a nuclear reactor located inside the hull of a nuclear-powered ship and two closed circuits, the first of which is a liquid circuit with a circulation pump, and the second is a steam circuit, including a steam generator, a steam turbine with an electric generator on the same shaft, a condenser and a liquid pump, wherein the liquid circuit passes through the nuclear reactor and the steam generator of the steam circuit, the electric generator is connected to the propeller electric motors and other electrical consumers of the nuclear-powered ship, and the steam circuit is equipped with a bypass line for maneuvering the steam turbine, containing a pickling control valve and a throttling device and connecting sections of the steam circuit after steam generator and in front of the condenser, bypassing the turbine, characterized in that it is equipped as a working fluid of the steam circuit with an organic working fluid in the form of pentane, a closed cooling circuit passing through the condenser of the steam circuit and containing an expansion tank, a circulation pump, a heat exchanger-heater through which it passes a circuit of thermal energy consumers of the nuclear-powered ship, and a heat exchanger-cooler, through which the sea cooling water line with a circulation pump passes.

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