RU2449391C2 - Method to increase capacity of double-circuit nuclear power unit - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: substance of the invention consists in using an additional heat exchanger connected into the first circuit downstream the reactor steam generator. The heat exchanger heats feedwater to the temperature of saturation prior to its supply into the steam generator.

EFFECT: invention makes it possible to increase nuclear reactor capacity due to reduction of coolant temperature at the inlet to the reactor core.

1 dwg

Description

The invention relates to the field of atomic energy and can be used primarily in nuclear power plants with nuclear-powered water-cooled nuclear reactors, nuclear power plants (NPPs) in order to increase power and efficient operation. In particular, the invention can be applied to serial and designed domestic NPP units with water-water reactors and turbines.

There is a method of obtaining additional electric power from a steam turbine by turning off the taps to regenerative heaters [1].

To compensate for the under-heating of feed water, hot water is throttled outside its flow under pressure, followed by a cascade of steam separation from it and the resulting steam is strained into low-pressure heaters (HDPE). Hot water under pressure is obtained in a special peak boiler-water heater due to the heat of combusted fossil fuels.

The disadvantage of this method is that it cannot be used with a complete technical analogy on the NPP units, since the scheme of heating flows to the high pressure heaters (LDPE) of the NPP turbine is more complex and in most cases only a nuclear reactor can be a reserve heat source.

There is also a method of obtaining additional power and efficient operation of nuclear power plants by short-term shutdown of high-pressure heaters and compensation of underheating of feed water [2].

This compensation is achieved by switching off the drainages of the heating steam of the intermediate separator-superheater from the high-pressure heaters and taking off the steam to the latter, when the LDPE is switched off, it is heated with the primary coolant of the nuclear reactor after the steam generator using a water-to-water heater (GDP) connected in parallel with the heaters high pressure (LDPE).

The disadvantage of this method is the compensation of underheating of feed water only when the high pressure heaters (LDPE) are turned off, the water-water heater is periodically turned on, and the GDP cannot be turned on when the LDPE is operating.

There is a method of increasing the efficiency of an atomic steam turbine installation by reducing energy consumption for its own needs, reducing the overall dimensions of the installation and the possibility of simultaneous production of electricity and heat [3].

To achieve this technical result, a steam-water heat power plant including a heat source with a coolant circuit passing through a steam generator, a steam turbine circuit containing a steam generator, a steam turbine, is equipped with a steam heat exchanger-heat exchanger in the steam turbine circuit, and the coolant circuit first passes through the heat exchanger first -heater, and then through the steam generator.

However, the introduction of a steam-water heat power installation located in the circuit of a steam-turbine installation of a heat exchanger-steam heater does not allow increasing the flow rate of the working fluid at the outlet of the steam generator.

The aim of the invention is to heat the feed water after the LDPE before feeding it to the steam generator to a temperature equal to or close to the saturation temperature.

The essence of the invention consists in the use of an additional heat exchanger connected to the first circuit after the reactor steam generator. Such heating of the feed water to the saturation temperature before feeding it to the steam generator significantly increases the productivity of the steam generator, and consequently, the electric power of the turbine with the same heat transfer surfaces. Moreover, such a heat exchanger (GDP) can work continuously, providing additional turbogenerator power in a round-the-clock mode.

The unit of the nuclear power plant for implementing the proposed method (Fig. 1) contains a series-connected reactor 2, a steam generator 6, through the surface of the steam generator 7, cold loops 5, a water-water heater 8, a circulation pump 4, an active zone of a nuclear reactor 1 and hot loops 3 through which coolant circulates.

The steam generator 6 is connected to a steam turbine consisting of a cylinder 9 high pressure (CVP), cylinder 10 medium pressure (TsSD) and cylinder 11 low pressure (TsND), from which steam is selected for regenerative heaters 18 high (LDPE) and low (HDPE) ) pressure 15. The turbines drive the electric generator 12, which generates electrical energy. The steam spent in the turbine enters the condenser 13. The condensate formed by the condensate pump 14, passing through the regenerative heating system using selective steam, the deaerator 16 is fed by the feed pump 17 to the water-water heater 8 included in the cold loops of the primary circuit after the steam generator. Feed water after LDPE is heated in a water-water heater 8 to a design temperature close to or equal to the saturation temperature, and is fed to a steam generator. The sequential inclusion of a water-water heater 8 after the LDPE allows to increase the steam capacity of the steam generator and to obtain additional power in the turbine on an ongoing basis with operating LDPE.

Thus, this method allows you to get additional power when working LDPE by additional heating of the feed water after LDPE in a heat exchanger installed on the cold line of the coolant after the steam generator. This ensures an increase in the power of a nuclear reactor by lowering the temperature of the coolant at the entrance to the active zone.

Information sources

1. USSR author's certificate No. 358530, cl. F01K 7/04, 1972.

2. USSR copyright certificate No. 2921335, cl. G21B 5/06 of 05/12/1980.

3. RF patent No. 2163670 dated 10.26.1999.

Claims (1)

A method of increasing the capacity of a dual-circuit nuclear power plant by heating feed water by supplying heat from a primary coolant passing through a steam generator, using a water-water heater, supplying it to a steam generator and receiving steam therein from heat supply, steam passing through a turbine, condensation of spent steam in a condenser and through a system of regenerative heaters for supplying feed water to a water-water heater, characterized in that feed water after heating in high heaters Before applying to the steam generator, heat is heated to a temperature close to or equal to the saturation temperature of the primary coolant passing through the steam generator by installing an additional heat exchanger.