RU2261337C1 - Power and heating plant with open power and heat supply system - Google Patents

Abstract

FIELD: power and heat generation.

SUBSTANCE: proposed power and heating plant with open power and heat supply system including boiler unit, steam turbine, deaerator and feed pump includes steam-gas turbine plant unit with low-pressure afterburning chamber, steam gas mixture heat recovery unit containing recovery boiler with high-and-pressure steam generators, spraying device, gas cooler-condenser and separated water utilization unit. Separated water utilization unit is connected with input of low-pressure steam generator of recovery boiler through water softening set and deaerator. Spraying device is connected with raw water softening device of power and heating plant. Input of high-pressure steam generator of recovery boiler is connected with output of steam-gas-turbine plant. Low-pressure steam generator of recovery boiler is connected with additional afterburning chamber of steam-gas turbine plant. Separated water utilization unit is connected by pipeline of softened and deaerated low-pressure feed water with steam-gas mixture heat recovery unit and pipeline of softened, heated and deaerated make-up water with open power and heat supply system. High-pressure steam generator is connected by feed water and steam pipelines with power and heating plant.

EFFECT: provision of effective modernization of steam turbine power and heating plants with increase of power and economy.

2 dwg

Description

A combined heat and power plant with an open heating system belongs to the field of energy and can be used for the joint production of electric and thermal energy.

Known combined gas-vapor installation of the type "Aquarius", containing a gas turbine installation with an air compressor, a combustion chamber with devices for supplying "ecological" and "energy" steam, a gas and steam turbine located in its exhaust gas duct, a waste heat boiler, an electric generator.

The recovery boiler contains a steam generator located along the gas-vapor mixture, an irrigation device, a contact gas cooler-condenser with a separation device. The irrigation device of the recovery boiler is connected to the chilled irrigation water supply pipe. The gas separation unit is connected to the atmosphere by the exhaust gas duct, and to the separated water storage tank through the separated water. The latter is connected to the inlet pipe of the steam generator by a feed water pipe. The steam generator is connected by a steam line to the combustion chamber. The second pipeline, the storage tank of the separated water is connected by pipelines through a water-cooling device to the separation device of the gas cooler-condenser. The rotor of a combined cycle gas turbine is connected by a shaft to the rotor of an air compressor and to the rotor of an electric generator [Romanov V.I., Krivutsa V.A. Combined gas-steam plant with a capacity of 16-25 MW with heat recovery from exhaust gases and water recovery from the combined-cycle gas stream. "Thermal Power" No. 4, 1966, pp. 27-30].

In a gas-steam installation of the Aquarius type, the generated steam is used only for injection into the combustion chamber, therefore this installation cannot be used to upgrade existing steam-turbine cogeneration plants.

A contact steam-gas combined heat and power plant with an open heating system is also known [Combined-cycle plant PGU-60S. Commercial offer. FSUE Salyut, 2005 "], containing an air compressor, a high-pressure combustion chamber with devices for the injection of" environmental "and" energy " steam, a high-pressure steam-gas turbine, a low-pressure steam-gas turbine, a backpressure steam turbine, an electric generator, a waste heat boiler, a separated water tank, a heat pump installation, a network heating installation. In a waste heat boiler installed in the exhaust gas duct behind a low-pressure steam and gas turbine, the heating surfaces of the steam generator, a network heater, an irrigation device and a gas-cooler-condenser with a separation device are placed sequentially along the gas-vapor mixture.

The separator device of the recovery boiler is connected through the flow of separated gases through the exhaust gas duct and the exhaust fan to the atmosphere, and through the separated water (condensate) it is connected by a pipeline to the separated water tank (capacity - condensate storage tank). The inlet pipe of the steam generator is connected by a feed water pipe to a separated water tank. The outlet pipe of the steam generator is connected by a steam line to the steam inlet body of the backpressure steam turbine, the exhaust of which is coupled in pairs by steam lines to the devices for injecting steam into the high-pressure combustion chamber. The inlet pipe of the heat pump installation is connected through a separated water pipe to the tank of separated water, and its outlet pipe through a separated water is connected by a pipe to the irrigation device of the recovery boiler. By heating network water, the heat pump installation is connected at the inlet to the return pipeline and at the outlet to the direct network water pipe of the open heating system.

The described contact combined-cycle plant is designed to create new highly efficient heating cogeneration units. It cannot be used for the modernization of basic steam turbine cogeneration plants, as its steam generator produces superheated steam with parameters below the standard for typical cogeneration turbines. In addition, it is connected by a steam line to a special backpressure steam turbine, the exhaust of which is connected by steam lines to devices for injecting steam into a high-pressure combustion chamber and a cooling system for a combined cycle gas turbine. In this installation, it is also impossible to use the existing gas turbine units with a split shaft and, as a consequence of this, there is a need to use a special combined-cycle turbine.

The closest in technical essence is a cogeneration plant with an open heating system [Sharapov V.I. Preparation of makeup water for heating systems using vacuum deaerators. M .: Energoatomizdat, 1996. - 176 p., P. 119, Fig. 8.2], containing a boiler, a main steam line, a cogeneration steam turbine with regenerative and cogeneration steam extraction, an electric generator, regenerative heaters of low and high pressure, high pressure deaerator, feed high pressure pump, closed heating system with network heaters, return and direct water pipelines. The boiler unit is connected by a main high pressure steam line to a cogeneration steam turbine, the rotor of which is connected by a shaft to the rotor of an electric generator. Regenerative extraction of steam from a cogeneration steam turbine is connected by steam pipelines to regenerative heaters, and its coffer taps are connected to network heaters of an open heating system, connected at the inlet to the return pipe, and at the outlet to the direct network water pipe of the heating system.

These steam turbine cogeneration plants have a relatively low profitability. Therefore, there is an urgent need to modernize these cogeneration plants with an increase in their thermal and economic efficiency, but due to the low thermodynamic efficiency of the steam-turbine cycles, their modernization and increase in efficiency are impossible.

The objective of the proposed technical solution is to create a combined cycle heat and power plant with an open heating system, which allows for the efficient modernization of the basic steam turbine power plants with an increase in their power and efficiency; at significantly reduced costs.

This goal is achieved due to the fact that the combined heat and power plant with an open heating system, containing a boiler, a main steam line, a heating steam turbine with heating steam extraction, a high pressure deaerator, a high pressure feed pump, an open heating system with network heaters, reverse and direct network water pipelines , is additionally equipped with a steam-gas-turbine unit with a low-pressure afterburner; a heat recovery unit for a steam-gas mixture containing a recovery boiler with a high-pressure steam generator and an additional low-pressure steam generator; irrigation device, gas cooler-condenser; a unit for using separated water, which is connected to the input of the low-pressure steam generator of the recovery boiler through a low-pressure feed water pipe through a softener and a deaerator; the irrigation device is connected by a pipeline to the raw water softener installation of the base cogeneration plant; in turn, the inlet of the high-pressure steam generator of the recovery boiler is connected by a steam-gas mixture pipeline to the outlet of a combined-cycle turbine installation; a low pressure steam generator of the recovery boiler is connected by a low pressure steam line to an additional afterburner of a steam-gas-turbine installation; the separated water use unit is connected by a softened and deaerated low-pressure feedwater pipeline to a steam-gas mixture heat recovery unit and a softened, heated and deaerated makeup water pipe with an open heating system of the base heat and power plant; the high-pressure steam generator is connected by pipelines of high-pressure feed water and high-pressure steam to the base cogeneration plant.

Using an additional low-pressure combustion chamber of a combined cycle gas turbine installation, placing it between a high-pressure gas turbine and a power gas turbine and injecting low-pressure steam into it from an additional low-pressure steam generator of a recovery boiler allows increasing the capacity of a combined cycle gas turbine plant and increasing the flow rate and temperature of a gas-vapor mixture at the inlet to waste heat boiler. Due to this, a high-pressure steam is generated in the steam generator, supplied to the base cogeneration plant, which makes it possible to upgrade this cogeneration plant with an increase in its power and efficiency.

At the same time, the temperature of the gas-vapor mixture behind the low-pressure steam-gas turbine in front of the recovery boiler ensures that it can generate superheated high-pressure steam with parameters standard for existing heating steam turbines. This makes it possible to expand the generated high-pressure steam in typical heating cogeneration steam turbines of the modernized combined heat and power plant, into which the high-pressure steam produced by the boiler units of this steam-turbine combined heat and power plant is also supplied and expanded.

The use of high-pressure feed water for generating steam prepared in the base steam-turbine cogeneration plant reduces the cost of preparing high-quality feed water.

The use of a base steam-turbine irrigation water system softened in a raw water softener, to condense steam from a steam-gas mixture of a steam-gas mixture heat recovery unit, and supply most of the separated water after its deaeration to replenish the heating network of an open heating system of a basic heat and power plant can further increase its additional efficiency.

The use of softened and deaerated separated water to generate low-pressure steam makes it possible to cheapen the installation for the preparation of low-pressure feed water.

In the proposed combined heat and power plant, it is possible to use turbochargers of existing gas turbine plants with a split shaft, which can significantly reduce the cost of creating such plants.

While maintaining the constant power of cogeneration steam turbines, steam production and fuel consumption for boiler units are reduced, and the thermal efficiency of the modernized steam-turbine cogeneration plant is increased.

Figure 1, shows a block diagram of a combined heat and power plant with an open heating system, figure 2 shows a schematic diagram.

The block diagram in figure 1 consists of four blocks:

basic heat and power plant with an open heating system 1; steam-gas-turbine unit 2; heat recovery unit of the gas-vapor mixture 3; block for the use of separated water 4.

Figure 2 shows a schematic diagram of a modernized cogeneration plant.

The basic heat and power plant with an open heating system 1 contains: a high pressure feed pump 29, high pressure feed water pipelines 8, high pressure regenerative heaters 30, boiler unit 31, main steam line 32, heating steam turbine 33, electric generator 34, steam line 35, high pressure deaerator 36 , open heating system 37, network heater 38, pipelines direct 39 and return 40 network water, softener installation for raw water 41, feed network 42.

The steam-gas-turbine unit 2 contains: an air compressor 13, a high-pressure combustion chamber 14, a high-pressure gas turbine 15 (compressor turbine), an afterburner 16, a low-pressure gas and steam turbine 17 (free power turbine), an electric generator 18, a gas-vapor mixture pipeline 6.

The heat recovery unit of the vapor-gas mixture 3 contains: a steam boiler-utilizer of two steam pressures 19, comprising a high pressure steam generator 20, a high pressure steam pipe 7, a low pressure steam generator 21, a low pressure steam pipe 5, an irrigation device 22, a gas cooler-condenser 23, an exhaust gas duct 24 with a smoke exhauster.

The separated water use unit 4 contains: a separated water pipe 12, a separated water tank 25, a low pressure feed water softener 26, a deaerator 27, a low pressure feed water pipe 11 with a feed pump, a pipe with a separated water pump 28, a softened irrigation water pipe 9 , pipeline of heated and deaerated make-up water 10.

The combined heat and power plant with an open heating system is as follows.

The boiler unit 31 of the base heat and power plant with an open heating system 1 is connected by a main steam line 32 to a heating steam turbine 33, which is connected by a steam line 35 to a network heater 38 of an open heating system 37. The high pressure deaerator 36 is connected through a high pressure feed pump 29 to one feed water pipe 8 through heaters high pressure 30 with the boiler unit 31 and the second feed water pipe 8 with the inlet of the high pressure steam generator 20 of the recovery boiler 19. ruboprovod return water 40 cogeneration base 1 is connected with one of makeup water conduit 42 with the installation of softening the raw water conduit 41 and a second heated water poldpitochnoy deaerator 10 with a yield of separated water tank unit 25 4.

In the duct between the air compressor 13 and the high pressure gas turbine 15 of the steam-gas-turbine unit 2, a high-pressure combustion chamber is installed 14. In the duct between the high-pressure turbine 16 and the low-pressure gas-turbine 17, an afterburner 16 is additionally equipped with a steam injection device. The output of the gas-vapor turbine low pressure 17 is connected by a pipeline gas-vapor mixture 6 with the waste heat boiler 19.

In the waste heat boiler 19 of the heat recovery unit of the gas-vapor mixture 3 along the gas-vapor mixture, a high-pressure steam generator 20, an additional low-pressure steam generator 21, an irrigation device 22, a gas cooler-condenser 23 with a separation device are placed. The exhaust gas duct of the waste heat boiler 19 is connected by a pipe 24 through an exhaust fan to the atmosphere. The output of the high pressure steam generator 20 is connected by a steam line 7 to the main steam line 32 of the base heat and power plant 1. The output of the low pressure steam generator 21 is connected by a steam line 5 to a low pressure afterburner 16, and its input is connected by a pipe 11 through a low pressure feed pump, a deaerator 27, and a feed water softener filter 26 with a separated water tank 25 of the separated water usage unit 4. The irrigation device 22 is connected by an irrigation water pipe 9 to a raw water softener 41 of unit 1. Separa ionic gas cooler-condenser unit 23, the separated water conduit 12 is connected to the input of the separated water tank 25.

The outlet of the separated water tank 25 is connected through a pump 28 to a make-up water pipeline 10 through a deaerator with a return line to the heating network 40 of block 1.

The raw water softener 41 is connected by a make-up water pipe 42 to a return pipe 40 of the open heating system 37 of block 1.

The combined heat and power plant with an open heating system works as follows.

Superheated high-pressure steam is generated in the boiler unit 31 of the base heat and power plant with an open heating system 1, it is fed through the main steam line 32 to the heating steam turbine 33 and expanded, the useful work of the steam turbine 33 is used to generate electricity in the electric generator 34. The steam from the regenerative samples of this steam turbines are used to heat feed water in regenerative feed water heaters 30. Steam from the steam line 35 in the network heater 38 is heated network water open heating system 37.

In the high-pressure deaerator 36, the feed water is de-aerated and the high-pressure feed pump 29 delivers part of it through the high-pressure regenerative heaters 30 to the boiler unit 31. The rest of the feed water is supplied through the high-pressure feed water pipe 8 to the inlet to the high-pressure steam generator 20 of the recovery boiler 19. From the outlet of the steam generator 20, superheated steam is supplied through the high pressure steam line 7 to the main steam line 32 of the base heat and power plant 1.

Atmospheric air is compressed by a compressor 13 of a steam-gas-turbine unit 2, directed to a high-pressure combustion chamber 14, and the supplied fuel is burned therein. The combustion products of the fuel are sequentially expanded in high-pressure turbines 15 and low pressure 17. The high-pressure gas turbine 15 of the steam-gas turbine unit 2 operates on the fuel combustion products leaving the main combustion chamber 14, and the low-pressure steam and gas turbine 17 runs on the gas-vapor mixture.

The useful work of a high-pressure gas turbine 15 is used to compress the air in the compressor 13. The fuel combustion products spent in the high-pressure gas turbine 15 are supplied with additional fuel heat to the afterburner 16. Here, low pressure steam 5 is supplied via a low pressure steam line 5. A high pressure gas turbine 15 operates on the products of fuel combustion, and a low pressure steam and gas turbine 17 operates on a gas mixture. The useful work of a low-pressure steam and gas turbine 17 is used to drive an electric generator 18 and generate electricity. The temperature of the gas-vapor mixture in front of a free power turbine is set close to 900 ° C - the maximum allowable for an uncooled gas turbine. From the power combined-cycle turbine 17 through the pipeline gas-vapor mixture 6 is fed into the recovery boiler 19 of the heat recovery unit of the gas-vapor mixture 3.

The heat of the vapor-gas mixture is utilized to generate superheated high-pressure steam in the high-pressure steam generator 20 and low-pressure steam in the low-pressure steam generator 21.

High pressure steam through the high pressure steam line 7 is fed into the main steam line 33 of the base cogeneration plant. Low pressure steam is sent through a low pressure steam line 5 to an additional afterburning chamber 16 of a combined cycle gas turbine unit 2.

Irrigation water with a temperature of 20-30 ° C is injected into the steam-gas mixture, partially cooled during the production of high and low pressure steam, in the irrigation device 22, supplied to it through the irrigation water pipe 9 from the raw water softener 41 of the base heat and power unit 1.

Due to this, the vapor component of the vapor-gas mixture is condensed in the gas cooler-condenser 23. In the separation device of the gas cooler-condenser 23, the condensate of the vapor-gas mixture and the irrigation water from the fuel combustion products are separated. The combustion products through the exhaust gas duct 24 with a smoke exhauster are discharged into the atmosphere, and the separated water is piped 12 to the separated water tank 25.

A smaller part of the separated water in block 4 is softened in the softener filter for low-pressure feed water 26, deaerated in the deaerator 27, and piped 11 through the low-pressure feed pump to the inlet to the low-pressure steam generator 21 of the recovery boiler 19. Most of it is separated by the pump of separated water 28 serves through the pipeline 10 recharge the heating system through the deaerator in the return pipe of the network water in the base cogeneration plant 1.

The proposed layout of the cogeneration plant with an open heating system has advantages both over the known analogues and over the prototype and provides for the modernization of the base cogeneration plants with an open heating system.

Claims (1)

A cogeneration plant with an open heating system, comprising a boiler, a main steam line, a cogeneration steam turbine with cogeneration, a high pressure deaerator, a high-pressure feed pump, an open cogeneration system with network heaters, reverse and direct water pipelines, characterized in that it is additionally equipped a gas-turbine unit with a low-pressure afterburner; a heat recovery unit for a steam-gas mixture containing a recovery boiler with a high-pressure steam generator and an additional low-pressure steam generator; irrigation device, gas cooler-condenser; a unit for using separated water, which is connected to the input of the low-pressure steam generator of the recovery boiler through a low-pressure feed water pipe through a softener and a deaerator; the irrigation device is connected by a pipeline to the raw water softener installation of the base cogeneration plant; in turn, the input of the high-pressure steam generator of the recovery boiler is connected by the steam-gas mixture pipeline to the output of the steam-gas-turbine installation; a low pressure steam generator of the recovery boiler is connected by a low pressure steam line to an additional afterburner of a steam-gas-turbine installation; the separated water use unit is connected by a softened and deaerated low-pressure feed water pipeline to a steam-gas mixture heat recovery unit and a softened, heated and deaerated make-up water pipeline with an open heating system of the base heat and power plant; the high-pressure steam generator is connected by pipelines of high-pressure feed water and high-pressure steam to the base cogeneration plant.

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