RU2317426C2 - 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 combustion products are cooled in convection steam superheater, water economizer, high-pressure gas-water heater and low-pressure gas-water heater, superheated steam after steam boiler steam superheater is directed to extraction steam turbine plant from controlled heating extractions of which steam is directed for heating system water in lower and upper system heaters, feed water deaerated in higher pressure deaerator is heated to required temperature before delivered into water economizer of steam boiler. Additional feed water after atmosphere deaerator is heated in water-to-water heater connected by heating medium line to deaerated water pipeline after higher pressure dearator, after which cooled deaerated water is directed successively into regenerative lower pressure heater and through feed pump, into high pressure gas water heater of steam boiler.

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.

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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 exhaust gases of a gas turbine installation (GTU) - an oxidizer for burning fuel is directed to burners and waste nozzles of a steam boiler, in the lowering duct of which the combustion products are cooled in a convective superheater, water economizer (VEK), gas-water the high-pressure heater (GWP VD) and the gas-water heater of low pressure (GWP ND), the steam generated in the steam boiler is sent to the high, medium and low pressure t steam-turbine platification unit (PTU), from the controlled heating selections of which steam is diverted to heat the mains water in the lower and upper network heaters, in the gas-water low-pressure heater, the main condensate of the steam-turbine installation is heated after regenerative low-pressure heaters connected to the sixth and seventh along the steam in the flow part of the steam turbine, the deaerated feed water is heated after the deaerator in a gas-water high-pressure heater Accelerating pressure before entering the water economizer (see. Nishnevich V.I., Slovikovsky G.B. Design of the PGU-190/220 power unit for the Tyumen TPP-1 // Electric stations. 2005. No. 6. S.9-16). This analogue is adopted as a prototype.

The disadvantages of the analogues and the prototype are the reduced cost-effectiveness of thermal power plants due to the insufficiently efficient use of the heat of the exhaust gases of the gas turbine and the reduced generation of electricity for heat consumption due to the exclusion of some of the heaters of the regeneration system of the gas turbine.

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 exhaust gases of a gas turbine installation - an oxidizing agent for fuel combustion - are directed to the burners of a steam boiler, in the downstream gas duct of which the combustion products are cooled in a convective superheater, a water economizer, a high-pressure gas-water heater and a low-pressure gas-water heater the pressure generated in the steam boiler, the steam is sent to the heating unit consisting of a part of high, medium and low pressure a rotary turbine installation, from which the steam is removed from the controlled heating taps to heat the network water in the lower and upper network heaters, the deaerated feed water in the high pressure deaerator is heated before being fed to the water economizer 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 a 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 in series to the steam connected from the medium pressure steam turbine plant regenerative low-pressure heater and through the feed pump into the gas-water heater is high of the boiler pressure.

The new interconnection of elements makes it possible to increase the efficiency of a thermal power plant by providing additional electricity production for heat consumption when heating the deaerated feed water with regenerative steam in a low-pressure heater, 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 the gas turbine.

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 fuel combustion, a heating steam turbine unit 2 with steam extraction for a low pressure regenerative heater 5, a water-water heater 6, connected via a heated medium to the feed water pipe 7 after an atmospheric deaerator 4, and in a heating medium, into the circulation pipeline 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 waste nozzles 13 of the steam boiler 1 for oxidation of 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 plant cycle are compensated by additional feed water after the atmospheric deaerator 4, which is sent to the water heater 6 before being fed to the high pressure deaerator 6. To the water heater 6 through pipeline 8 supply a heating medium - deaerated feed water after the high pressure deaerator 9 and circulation pump 10, which is then sent sequentially to regenerative heating low pressure generator 5, through the feed pump 11 in the high-pressure water supply VD and further to the VEK of the steam boiler 1.

Thus, the proposed solution makes it possible to provide the required heating of the additional feed water in front of the high pressure deaerator and at the same time create conditions for additional electricity generation from the heat consumption by steam selection, taken from a part of the average pressure of the steam turbine unit, 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, are directed to the burners of a steam boiler, in the lowering gas duct of which the combustion products are cooled in a convective superheater, a water economizer, a gas-water high-pressure heater, the steam generated in the steam boiler is sent to the heating steam turbine unit, from the controlled heating selections of which steam is diverted to heat the network water in the lower and upper network heaters The deaerated feed water in the high pressure deaerator is heated to the required temperature before being fed to the steam boiler water economizer, characterized in that the heating of the additional feed water after the 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 water feed water is sent for heating sequentially in the steam turbine unit connected to the selection of steam ovki regenerative heater and low pressure through the feed pump to the high pressure gas-water heater of the steam boiler.