RU2208171C1 - Heat power station - Google Patents

Abstract

FIELD: heat power engineering. SUBSTANCE: invention relates to heat systems of heat power stations. Electric station considered as prototype uses network heating plants only during heating sea sons. However, during summer period, at no heat demand, network heating plants are cut out with resulting downtime of equipment. Proposed invention makes it possible to prevent downtime of equipment owing to the fact two pipelines with shutoff and control devices connecting lines of main condensate and heating system water located before and after heaters supplied with steam of one steam extractions are included additionally into electric station system. EFFECT: increased economy of heat power station owing to use of idling heaters. 1 dwg

Description

 The invention relates to a power system, mainly to schemes of thermal power plants.

 The invention is intended to improve the efficiency of the thermal power plant.

 The well-known thermal power plant [Journal of Heat, 2, 2000, p. 9] contains a steam boiler connected by a steam line to a steam turbine installed with an intermediate superheater and consisting of a combined part of high and medium pressure and part of low pressure. The turbine unit is connected by a pipeline to a condenser. The condenser is connected by a condensate line through a condensate pump, low pressure regenerative heaters, a mains pump, and a deaerator. The deaerator is piped through a feed pump, as well as high pressure regenerative heaters with a steam boiler. In addition, the steam turbine is connected by steam lines with regenerative heaters of high and low pressure and a deaerator.

 The thermal power station contains network steam-water heaters connected by steam pipelines with steam extraction from the turbine unit. Network heaters are connected through a network pump to a heat consumer.

 Thermal power station operates as follows. Steam from the boiler is supplied through a steam line for mechanical work to a steam turbine unit. After the work has been completed, the steam is condensed in the condenser and, in the form of condensate, is supplied through the condensate pump via a condensate pump and a mains pump through regenerative low-pressure heaters to the deaerator. From the deaerator, feed water is fed through a pipeline through regenerative high-pressure heaters to a boiler unit. In the direction of travel, the condensate is heated by selective steam entering the regenerative low-pressure heaters through steam pipelines from the turbine unit. Then the condensate is deaerated in the deaerator with steam coming from the turbine through the steam line. After the deaerator, the feed water is heated in regenerative high-pressure heaters with steam coming through pipelines.

 Network heaters heat the network water with steam from a turbine unit coming through steam pipelines from the selections.

 The disadvantage of this scheme is the non-use of network heaters in the summer non-heating period when there is no heating load.

 The presented invention improves the efficiency of a thermal power plant. This is achieved by the fact that a thermal power station containing a turbine with sampling pipes, regenerative heaters of high and low pressure, a deaerator, a condenser and condensate pumps, network heaters, is additionally equipped with two pipelines with shut-off and regulating devices connecting the main condensate and mains water lines, located before and after heaters that feed on steam from a single selection.

 The drawing shows a diagram of the inventive thermal power station.

 The thermal power station contains a steam boiler 1, connected by a steam line 2 to a steam turbine 3, made with an intermediate superheater 4 and consisting of a combined high and medium pressure part and a low pressure part. The turbine unit is connected by a pipe 5 to a condenser 6. The condenser 6 is connected by a condensate line 7 to a deaerator 14 through a condensate pump 8, regenerative low-pressure heaters 10, 11, 12, 13, a network pump 9. The deaerator 14 is connected by a pipe 28 to a steam boiler 1 through a feed pump 15 as well as through regenerative high pressure heaters 16, 17. In addition, the steam turbine 3 is connected by steam lines 21, 22, 23, 24, 25, 26, respectively, with regenerative heaters of high 17, 16 and low 13, 12, 11, 10 pressure. The pipe 22 also connects the turbine 3 with the deaerator 14. The thermal power station contains steam-water network heaters 19, 20 connected by steam lines 23, 24 to the turbine unit 3. The network heaters 19, 20 are connected via a pipe 18 to the heat consumer 35 via a pipe 34. In addition, , the presented diagram additionally contains pipelines 32, 33 with shut-off valves 27, 28, which connect the main condensate heating line 7 to the network water heating line 34. Additionally, shut-off valves are included in the circuit: 31, located after the connection of the pipeline 33 to the main condensate heating line 7, and 30 - before the inclusion of the pipeline 33 into the network water heating line 34 and 29 after the connection of the pipeline 32 to the network water heating line 34.

 During operation, this technical invention works as follows.

 After passing through the low-pressure heater 12, the condensate is divided into two streams, one of which flows through the shut-off-regulating device 31 to the low-pressure heater 13, and the other through the pipeline 33, through the shut-off-regulating device 28 to the network heater 20. Both condensate streams are heated steam from the turbine 3 entering the low pressure heater 13 and the network heater 20 through the pipe 23. As a result, the entire mass flow of condensate is heated not only in the low pressure heater 13, as in the prototype, but also in the network heater 20. Therefore, the heating surface of the condensate increases, which leads to an increase in the amount of heat transferred from steam to condensate. As a result, the amount of underheating of the condensate decreases, which leads to an increase in the temperature of the condensate at the outlet of the network heater 20 and the low pressure heater 13. After heating in the low pressure heater 13, condensate enters the deaerator 14. Condensate from the network heater 20 is through a pipe 32 with a shut-off and control valve valve 27 returns to the heating line of the main condensate and also enters the deaerator 14. Since the temperature of the condensate entering the deaerator 14 is higher than in the prototype, therefore the temperature difference by which it is necessary to warm the condensate in the deaerator 14 will be less. As a result of this, the amount of steam that is required to heat the condensate in the deaerator 14 will be less than in the prototype. In turn, reducing the steam consumption for regenerative selection allows you to increase the production of electric energy due to the fact that the saved high-potential steam will continue to work in the last compartments of the turbine 3.

 Thus, the presented scheme of a thermal power plant, which has a number of significant structural differences, allows to achieve an increase in the energy and economic indicators of the station while maintaining a constant steam flow into the turbine head and without additional fuel costs.

Claims (1)

 A thermal power station containing a turbine with sampling pipes, high and low pressure regenerative heaters, a deaerator, a condenser and condensate pumps, network heaters, characterized by the presence of two additional pipelines with shut-off and regulating devices connecting the main condensate and mains water lines located before and after steam heaters from one selection.