RU2317425C2 - Method of operation of thermal power station - Google Patents

Abstract

FIELD: heat power engineering.

SUBSTANCE: according to proposed method of operation of thermal power station, waste gases of gas-turbine plant-oxidizer for combustion of fuel are directed to burners of steam boiler in downtake gas duct of which convection steam superheater, water economizer, high-pressure gas-water heater and low-pressure gas-water heater are installed, and superheated steam after steam boiler steam superheater is directed into extraction steam turbine plant from controlled steam extractions of which steam is directed to heat heating system water in lower and upper system heaters, feed water deaerated in higher pressure deaerator is directed through feed pump into high-pressure gas-water heater of steam boiler. Additional feed water after atmospheric deaerator is heated in water-to-water heater connected by heating medium line to deaerated water pipeline after higher pressure deaerator after which cooled deaerated water is directed for heating, successively, in steam boiler high-pressure gas-water heater and group of heaters of high-pressure regeneration system of steam turbine plant.

EFFECT: increased economy of thermal power station owing to provision of conditions for additional power generation at heat consumption of steam turbine and more complete utilization of excess heat of waste gases of gas-turbine plant.

1 dwg

Description

The invention relates to the field of power engineering and can be used in thermal power plants.

Known analogues are the methods of operation of a thermal power plant, in which the flue gases of a gas turbine installation (GTU) - an oxidizer for burning fuel - are directed to burners and waste nozzles of a steam boiler, in the lowering duct of which there is a convective superheater, water economizer (VEK), high-temperature gas-water heater pressure (ГВП ВД) and gas-water low-pressure heater (ГВП НД), steam generated in the steam boiler is sent to the cogeneration steam-turbine unit (ПТУ), from regulated heating x withdrawals of which steam is diverted to heat the mains water in the lower and upper mains heaters, the deaerated feed water after the high-pressure deaerator is heated in the gas-water high-pressure heater (see Nishnevich V.I., Slovikovsky GB, Design of the PGU-190/220 power unit for the Tyumen TPP-1 // Power plants. 2005. No. 6. S.9-16). This analogue is adopted as a prototype.

The disadvantages of the analogues and the prototype are the reduced efficiency of thermal power plants due to the insufficiently efficient use of the heat of the exhaust gases of a gas turbine and the reduced generation of electricity for heat consumption due to the exclusion of a high pressure regeneration system of a gas turbine unit.

The technical result achieved by the present invention is to increase the efficiency of a thermal power plant by creating conditions for additional power generation from the heat consumption of the steam turbine unit and more complete use of the excess heat of the flue gases of the gas turbine unit.

To achieve this result, a method is proposed for operating a thermal power plant, in which the flue gases of a gas turbine unit - an oxidizer for burning fuel - are directed to the burners of a steam boiler, in the lowering duct of which there is a convective superheater, a water economizer, a gas-water high-pressure heater and a gas-water low-pressure heater, the steam generated in the steam boiler is sent to the cogeneration steam-turbine unit, from the controlled heating selection of which It emits steam to heat the network water in the lower and upper network heaters, the deaerated feed water in the deaerator of high pressure is sent through the feed pump to the gas-water high-pressure heater of the steam boiler.

The peculiarity lies in the fact that the heating of the additional feed water after the atmospheric deaerator is carried out in a water-water heater connected to the pipeline of the deaerated feed water after the deaerator of high pressure via a heating medium, after which the deaerated feed water is sent for heating sequentially to the high-pressure gas-water heater of the steam boiler and regenerative heaters of a high pressure of a steam turbine installation.

The new interconnection of elements makes it possible to increase the reliability and efficiency of a thermal power plant by providing additional power generation for heat consumption when heating feed water in high pressure regenerative heaters, due to the standard quality of deaeration of the total feed water flow in the high pressure deaerator due to the heating of the additional feed water to the required temperature and due to a more complete use of the heat of the exhaust gases of gas turbines.

Next, we consider the information confirming the possibility of carrying out the invention with obtaining the desired technical result.

The drawing shows a schematic diagram of a thermal power station. The station contains a steam boiler 1, using the exhaust gases of a gas turbine unit 3 as an oxidizing agent for burning fuel, a heating steam turbine unit 2 with steam extraction for high pressure regenerative heaters 5, a water-water heater 6, connected via a heated medium to the feed water pipe 7 after atmospheric deaerator 4, and in the heating medium - into the circulation pipe of deaerated feed water 8 after the deaerator of high pressure 9 and the circulation pump 10.

Consider an example of the implementation of the claimed method of operation of a thermal power plant.

The flue gases of the gas turbine unit 3 are directed to the burners 12 and the discharge nozzles 13 of the steam boiler 1 for oxidizing the fuel entering the furnace. The steam generated in the steam boiler is sent to the cogeneration steam turbine unit 2. The losses of steam and condensate from the station cycle are compensated by additional feed water after an atmospheric deaerator 4, which, before being fed to the high pressure deaerator 9, is sent to the water-to-water heater 6. To the water-to-water heater 6 through a pipe 8 serves a heating medium - deaerated feed water after the deaerator high pressure 9 and the circulation pump 10, which is then sent by the feed pump 11 in series GWP VD, regenerative heaters of high pressure 5 and further in VEK of a steam boiler 1.

Thus, the proposed method allows to provide the required heating of the additional feed water in front of the high pressure deaerator and to create conditions for heating the feed water in high pressure regenerative heaters of a steam turbine plant without reducing the efficiency of using the heat of the exhaust gases of the steam boiler, i.e. increase the reliability and efficiency of the power plant.

Claims (1)

The method of operation of a thermal power plant, in which the exhaust gases of a gas turbine unit - an oxidizer for burning fuel - is directed to the burners of a steam boiler, in the lowering duct of which there is a convective superheater, a water economizer, a gas-water high-pressure heater, the steam generated in the steam boiler is sent to a heating steam turbine installation , from the controlled heating selections of which steam is diverted to heat the network water in the lower and upper network heaters, deaerated in a high pressure deaerator, feed water is sent through a feed pump to a gas-water high-pressure heater of a steam boiler, characterized in that the heating of the additional feed water after an atmospheric deaerator is carried out in a water-water heater connected via a heating medium to the deaerated water pipeline after the high pressure deaerator, after which deaerated feed water is sent for heating sequentially to a gas-water high-pressure heater of a steam boiler and regenerative high-pressure heaters of a steam turbine installation.