RU2293852C1 - Thermal power station operating process - Google Patents

Abstract

FIELD: thermal engineering; thermal power stations.

SUBSTANCE: proposed operating process implies that demineralized water is heated upstream of atmospheric makeup deaerator to ensure normal operation using for the purpose stable low-potential heat source. To this end steam is taken from three first extraction points of type T extraction turbine for high-pressure regenerative heaters and from four last ones, for low-pressure regenerative heaters wherein full-flow condensate is sequentially heated downstream of turbine condenser and feedwater; delivery-water heating steam is taken from seventh and sixth extraction points of type T turbine for bottom and top delivery-water heaters, respectively; demineralized water is heated prior to its supply to atmospheric makeup deaerator in heating-medium steam-water heat exchanger using steam from fifth extraction point of type T turbine that has heating-steam extraction stages.

EFFECT: enhanced reliability and economic efficiency of thermal power station.

1 cl, 1 dwg

Description

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

Analogs are known - methods of operating a thermal power plant, in which steam is transferred to the high pressure regenerative heaters from the first three samples of the T type cogeneration turbine, and from the last four to the low pressure regenerative heaters, in which the main condensate after the turbine condenser and feed water are sequentially heated , from the seventh and sixth selections of a turbine of type T steam is diverted to heat the network water, respectively, in the lower and upper network heaters, the purge water is a steam generator the torus is sent to a continuous purge cooler, in which demineralized water is heated in front of the atmospheric deaerator of additional feed water (see Elizarov D.P. Thermal Power Plants of Power Plants. - 2nd ed., revised. - M.: Energoizdat, 1982, Fig. 5.3 p. 103-104). This analogue is adopted as a prototype.

The disadvantages of the analogues and the prototype are the reduced reliability and efficiency of thermal power plants due to the insufficient flow rate of the steam generator purge water for the stable heating of demineralized water to the technologically necessary temperature in front of the atmospheric deaerator of the additional feed water, especially when the flow of additional feed water increases due to an increase in steam and condensate losses from the cycle station. Insufficient heating of demineralized water in front of the atmospheric deaerator leads to a deterioration in the quality of deaeration of additional feed water due to non-compliance with the requirements of the standard for the temperature regime of the deaerator type DA.

The technical result achieved by the present invention is to increase the reliability and efficiency of a thermal power plant by providing technologically necessary heating of demineralized water in front of an atmospheric deaerator of additional feed water by using a stable source of low potential heat.

To achieve this result, a method of operating a thermal power plant is proposed, in which steam is transferred to the high pressure regenerative heaters from the first three samples of the T type cogeneration turbine, and from the last four to low pressure regenerative heaters, in which the main condensate is subsequently heated after the turbine condenser and feed water, from the seventh and sixth selections of a T-type turbine, steam is diverted to heat the mains water, respectively, in the lower and upper network heaters, both salted water is heated in a steam-water heat exchanger before supplying additional feedwater to the atmospheric deaerator.

The peculiarity lies in the fact that as a heating medium in a steam-water heat exchanger use steam of the fifth selection of a type T turbine with heating steam extraction.

A new method of operation of a thermal power plant improves the reliability and efficiency of a thermal power plant by ensuring the standard quality of deaeration of additional feed water in an atmospheric deaerator by heating demineralized water to a technologically necessary temperature with a low-grade fifth turbine of the T type.

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 plant, explaining the proposed method.

The station contains a steam boiler 1, a T 2 type cogeneration turbine with seven steam take-offs 3-9, a condenser 10, a main condensate pipeline of the turbine 11 connected to the condenser 10 and a condensate pump 12 included in it, regenerative low-pressure heaters 13, lower and upper network heaters 14 and 15, connected to the seventh 9th and sixth 8th turbine sampling, a steam-water heater 16, connected via a heated medium in a demineralized water pipe 17 between the continuous purge cooler 18 and the atmospheric deaerator net feed water 19 and connected by a pipe 21 to the fifth selection of steam 7.

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

The steam generated in the steam boiler 1 is sent to the turbine 2 and condensed in the condenser 10, the main condensate of the turbine is pumped by the condensate pump 12 sequentially through the regenerative low pressure heaters 13 and then to the high pressure deaerator 20, after which the deaerated water is supplied by the feed pump through the high pressure regenerative heaters to the steam boiler 1. The losses of steam and condensate from the plant cycle are compensated by demineralized water, which is subsequently heated in a continuous cooler roduvki 18 and the steam heater 16 before being fed into the atmospheric deaerator incremental feedwater heater 19. The steam conduit 16 to the heating medium 21 is fed from the steam turbine 7 of the fifth selection.

Thus, the proposed method allows to provide the required heating of demineralized water in front of the atmospheric deaerator of additional feed water, irrespective of the values of the flow of continuous purging and losses of steam and condensate from the plant cycle, i.e. increase the reliability and efficiency of the power plant.

Claims (1)

The method of operation of a thermal power plant, in which steam is transferred to the high pressure regenerative heaters from the first three samples of the T type cogeneration turbine, and of the last four to low pressure regenerative heaters, in which the main condensate after the turbine condenser and feed water are sequentially heated from the seventh and the sixth sampling of a type T turbine, steam is diverted to heat the network water, respectively, in the lower and upper network heaters, desalinated water is heated in steam-water heat a heat exchanger before supplying additional feedwater to the atmospheric deaerator, characterized in that the fifth-type steam of a turbine of type T with heating steam is used as a heating medium in a steam-water heat exchanger.