RU44145U1 - CONTACT STEAM-GAS POWER PLANT - Google Patents

Abstract

A combined cycle gas turbine power plant belongs to the field of energy, and can be used to modernize basic steam turbine power plants, including combined heat and power plants used for the joint production of electric and thermal energy. The objective of the proposed technical solution is to create a contact combined cycle power plant that allows for the efficient modernization of basic steam turbine power plants, including combined heat and power plants with an increase in their power and efficiency, at significantly reduced costs. This goal is achieved due to the fact that the contact combined-cycle power plant includes a steam-gas-turbine unit having an air compressor, sequentially installed along the combustion products, a high pressure turbine and a low pressure power turbine, an electric generator; a unit for heat recovery of a gas-vapor mixture, including a waste heat boiler installed in the gas duct behind the low-pressure power turbine, in which a steam generator, an irrigation device, a gas cooler-condenser with a separation device are placed sequentially along the gas-vapor mixture, the output of the gas-cooler-condenser is connected to the atmosphere through the exhaust a gas pipeline and a smoke exhauster, while the steam-gas-turbine unit contains an additional low-pressure fuel post-combustion chamber located between gas turbines in HIGH-and low-pressure steam pipe and connected with a low pressure steam generator, further arranged in the waste heat boiler unit heat recovery steam-gas mixture; the output of the high pressure steam generator of the recovery boiler is connected by a steam line to the base steam turbine power plant. A positive result from the use in the power industry of the proposed combined cycle gas power plant is that this device provides an effective modernization of the basic steam turbine power plants, including heat and power plants with an increase in their power and efficiency. In the proposed combined cycle gas-fired power plant, it is possible to use turbochargers of existing gas turbine plants with a split shaft (for example, from a gas turbine power plant NK-37), which will significantly reduce the cost of creating such plants.

Description

A combined cycle gas turbine power plant belongs to the field of energy, and can be used to modernize basic steam turbine power plants, including combined heat and power plants 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 a device for supplying it with "environmental" 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 gas separation unit of the recovery boiler is connected by the exhaust duct to the atmosphere and has a separate water discharge pipe. The irrigation device of the recovery boiler is connected to the chilled irrigation water supply pipe. The inlet pipe of the steam generator of the recovery boiler is connected to the feed water pipe, and its outlet pipe is connected by a steam pipe to the devices for supplying “ecological” and “energy” steam to the combustion chamber. 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 the described 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.

The closest in technical essence is the contact combined-cycle heat and power plant [“Combined-cycle gas turbine unit CCGT - 60 C. Commercial offer. FSUE “Salyut”, 2005 ”], containing an air compressor, a high-pressure combustion chamber with devices for injecting“ ecological ”and“ energy ”steam, a high-pressure steam-gas turbine, a low-pressure steam-gas turbine, a backpressure steam turbine, an electric generator, a steam waste heat boiler, separated water tank, heat pump installation, network heating installation. In the waste heat boiler installed in the exhaust gas duct behind the low-pressure steam and gas turbine, the heating surfaces of the steam generator are arranged sequentially along the gas-vapor mixture

heating installation, irrigation device and gas cooler-condenser with a separation device. The irrigation device is connected to the chilled irrigation water supply pipe. The separating device of the recovery boiler is connected through the flow of separated gases through the exhaust gas duct and exhaust fan to the atmosphere, and through the separated water to the separated water discharge pipe. The inlet pipe of the steam generator of the recovery boiler is connected to the feed water pipe, and its outlet pipe is connected through the steam pipe and the backpressure steam turbine with steam injection devices into the high pressure combustion chamber. The rotor of a combined cycle gas turbine of high pressure is connected by a shaft to the rotor of an air compressor, and the rotor of a power combined cycle gas turbine of low pressure is connected through a reduction gear to the rotor of an electric generator. The counterpressure steam turbine rotor is connected via a reduction gear to the rotor of the electric generator.

The contact combined-cycle plant-prototype is designed to create new highly efficient heating cogeneration units. It cannot be used for the modernization of basic steam turbine thermal power plants, including combined heat and power plants, since its steam generator produces superheated steam with parameters below the standard for typical 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 steam injection devices into the high-pressure combustion chamber and a combined-cycle turbine cooling system; in the prototype installation, it is also impossible to use existing gas turbine plants with a split shaft and as a result of this there is a need for the use of a special combined-cycle turbine.

The objective of the proposed technical solution is the creation of a contact combined cycle power plant that allows for the efficient modernization of basic steam turbine power plants, including combined heat and power plants with an increase in their power and efficiency, at significantly reduced costs.

This goal is achieved due to the fact that the contact combined-cycle power plant includes a steam-gas-turbine unit having an air compressor, sequentially installed along the combustion products, a high pressure turbine and a low pressure power turbine, an electric generator; heat recovery unit for a gas-vapor mixture, including a waste heat boiler installed in the gas duct behind the low-pressure power turbine, in which the steam generator, an irrigation device, a gas cooler-condenser are arranged in series with the separation device, the gas cooler-condenser output is connected

with the atmosphere through the exhaust gas pipe and the exhaust fan, while the steam and gas turbine unit contains an additional low-pressure fuel post-combustion chamber located between the high and low pressure gas turbines and connected by the steam line to the low pressure steam generator, additionally placed in the heat recovery boiler of the steam and gas mixture heat recovery unit; the output of the high pressure steam generator of the recovery boiler is connected by a steam line to the base steam turbine power plant.

The drawing of figure 1 shows a diagram of the proposed contact combined cycle power plant. It consists of a steam-gas-turbine unit 1 and a heat recovery unit for a gas-vapor mixture 2.

The steam-gas-turbine unit 1 contains: an air compressor 5, a high-pressure combustion chamber 6, a high-pressure gas turbine 7, an afterburner 8, a low-pressure gas-turbine 9, an electric generator 10, a gas duct 4.

The heat recovery unit for the gas-vapor mixture 2 contains: a low pressure steam pipe 3, a steam recovery boiler 11, a high pressure steam pipe 12, a high pressure steam generator 13, a high pressure feed water pipe 14, a low pressure steam generator 15, a feed water pipe 16, an irrigation water supply pipe 17, an irrigation device 18, a gas cooler-condenser 19, an exhaust gas duct 20 with a smoke exhaust, a drainage pipe for separated water 21.

Contact combined-cycle power plant is as follows. In the duct between the air compressor 5 and the high-pressure gas turbine 7, a high-pressure combustion chamber is installed 6. The rotor of the air compressor 5 is connected by a shaft to the rotor of the high-pressure gas turbine 7. In the duct between the high-pressure turbine 7 and the low-pressure gas turbine 9, an afterburner 8 equipped with a device for the injection of "environmental" and "energy" steam. The rotor of a low-pressure gas turbine 9 is connected by a shaft to the rotor of an electric generator 11.

The output of a combined cycle gas turbine 9 is connected by a gas duct 4 to the input of a recovery boiler 11. In a recovery boiler 11, a high pressure steam generator 13, a low pressure steam generator 15, an irrigation device 18, a gas cooler-condenser 19 with a separation device are placed. The exhaust gas duct of the recovery boiler 11 is connected by a pipe 19 through a smoke exhauster to the atmosphere. The input of the high pressure steam generator 13 of the recovery boiler 11 is connected by a high pressure feed water pipe 14. The output of the high pressure steam generator

pressure 13 of the recovery boiler 11 is connected through a high-pressure steam line 12 to the base steam-turbine power unit. The input of the low pressure steam generator 15 is connected to the low pressure feed water pipe 16. The irrigation device 18 is connected to the irrigation water pipe 17. The separator device of the gas cooler-condenser 19 of the recovery boiler 11 is connected through the flow of separated gases through the exhaust gas duct 20 and the exhaust fan with the atmosphere, and separated water with a separated water discharge pipe 21.

The proposed contact combined cycle power plant operates as follows. Atmospheric air is compressed in the compressor 5 and fed into the high pressure combustion chamber 6, where the bulk of the fuel is burned. The combustion products of the fuel are expanded in a high-pressure gas turbine 7 leading to an air compressor 5. After the expansion of the combustion products in a high-pressure gas turbine 7, fuel is supplied into an additional afterburning chamber 8 and steam is injected into the combustion products from the low-pressure steam generator 15 and a vapor-gas mixture is obtained , the temperature of which before the second stage of expansion in a low-pressure gas turbine is set mainly at a level close to 900 ° C - the maximum allowable temperature for uncooled gas turbine. The heat of the combined-gas mixture spent in the power turbine 9 is supplied to the inlet of the waste heat boiler 11 through a gas duct 4.

In the high-pressure steam generator 13 of the recovery boiler 11, high-pressure steam is generated with parameters standard for typical steam turbines and it is diverted from the output of the steam generator through the steam line 12 to the base steam turbine power plant. At the entrance to the high-pressure steam generator 13, deaerated feed water is supplied via line 14.

In the low-pressure steam generator 15 of the recovery boiler 11, low-pressure steam is generated and sent via the steam line 3 to the steam injection device of the afterburner 8. The resulting gas-vapor mixture is expanded in the power turbine 9. Useful work of the power turbine 9 is used to drive the generator 10. Feed water in a low pressure steam generator 15 is supplied via a low pressure feed water pipe 16.

Cooled irrigation water is supplied to the vapor-gas mixture exiting the low-pressure steam generator 15 through the pipe 17 and through the irrigation device 18, due to which the vapor component of the vapor-gas mixture is condensed in the condenser-gas cooler 19. The gases purified from water in the separation device of the condenser-gas cooler 19 through the exhaust gas duct 20 and the exhaust fan are discharged into

the atmosphere. The separated water is discharged from the condenser-gas cooler 19 through the pipe 21.

The proposed contact combined cycle power plant eliminates the disadvantages of the known analogues and prototype. It employs an additional low-pressure afterburner placed in the gas duct between the high and low pressure gas turbines and equipped with a device for injecting steam into the combustion products, which allows expanding the gas-vapor mixture with high temperature and high flow rate in the low-pressure gas turbine, and increasing the useful power power turbine and electric generator. Increasing the temperature and flow rate of the gas-vapor mixture into the recovery boiler increases its heat output and allows it to generate both high-pressure steam with parameters standard for steam turbines of basic steam-turbine power plants, and low-pressure steam injected into the additional afterburner.

This allows you to expand the high-pressure steam generated in the recovery boiler in steam turbines of basic steam turbine power plants, including combined heat and power plants, due to which they can be upgraded with increased power and efficiency.

The generation of low pressure steam in the recovery boiler allows this steam to be injected into an additional low pressure afterburner and to obtain a high-temperature vapor-gas mixture at the inlet of the power turbine.

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

A positive result from the use in the power industry of the proposed combined cycle gas power plant is that this device provides an effective modernization of the basic steam turbine power plants, including heat and power plants with an increase in their power and efficiency. In the proposed combined cycle gas-fired power plant, it is possible to use turbochargers of existing gas turbine plants with a split shaft (for example, from a gas turbine power plant NK-37), which will significantly reduce the cost of creating such plants.

Claims (1)

The contact combined-cycle power plant contains a heat recovery unit for the combined gas and gas mixture, including a recovery boiler installed in the gas duct behind the low-pressure combined-cycle gas turbine, in which a steam generator, an irrigation device, a gas cooler — a condenser with a separation device, and a gas cooler — condenser outlet are connected in series with the atmosphere through the exhaust gas pipe and exhaust fan, while the steam-gas-turbine unit contains an additional fuel afterburner low pressure willow located in the duct between the gas turbines of high and low pressure and connected by a steam line to a low pressure steam generator, additionally placed in a heat recovery boiler of the heat and gas mixture heat recovery unit; the output of the high pressure steam generator of the recovery boiler is connected by a steam line to the base steam turbine power plant.