RU2545115C2 - Power plant - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: invention relates to power industry and can be used for generation of electric energy at fuel utilisation by its combustion in flames, namely to low-duty power plants. A power plant includes a housing in the form of a stack, which is energetically isolated from environment, a bladed machine, with a possibility of operation in a compressor mode, a turbine drive, an electric generator in the form of a payload unit, a combustion chamber, atmospheric air supply elements, fuel supply elements, for example associated petroleum gas, and a high-temperature recuperative heat exchanger. A low-temperature recuperative heat exchanger is introduced to the power plant, and it is provided as an additional drive with at least one pneumatic motor, the inlet of which is interconnected with the compressor outlet, and the outlet of the pneumatic motor is interconnected through the combustion chamber and the stack cavity with atmosphere. The low-temperature recuperative heat exchanger is located in the stack cavity after the high-temperature recuperative heat exchanger. Each pneumatic motor is connected to one electric generator being its only drive.

EFFECT: invention is aimed at improvement of efficiency of a power plant, increase of thermal efficiency, simplification of the design as a whole and enlargement of a range of stable operation.

3 cl, 3 dwg

Description

The invention relates to the field of energy and can be used to generate electricity and / or heat energy, including the utilization, for example, of crude petroleum gas by burning it, in particular to low-power power plants oriented to a wide range of fuels: liquid, gaseous, solid waste from the forestry and agricultural industries, biogas, household waste products, underground or industrial gasification of solid fuels, oil and petroleum waste processing and applying the power plant also for autonomous power supply of residential buildings, shopping centers, office buildings, pools, hospitals, catering facilities.

Fundamentally in low-power power plants, various types of units are used: internal combustion engines, steam and gas turbines, or combinations thereof.

Along with the technical task - the conversion of heat energy of flaring of associated petroleum gas into electric energy - another environmental problem is being solved - one of the most important tasks of our time - reducing the harmful effects on the ecosystem.

Natural gas, which comes from oil wells, usually exists in combination with other hydrocarbons, such as ethane, propane, butane and pentane. In addition, raw natural gas contains water vapor, hydrogen sulfide (H ₂ S), carbon dioxide, nitrogen and other components. Associated petroleum gas containing such impurities is difficult to transport, and it is also difficult to use without additional purification after its receipt in the oil production process.

The problem of associated petroleum gas utilization is facing all oil companies. For oil workers, the transportation and processing of associated petroleum gas for further use is unprofitable, since the cost of such fuel will be higher than the market price. At the moment, associated petroleum gas in large quantities is flared. The use of associated petroleum gas in the energy sector will solve the problem of heat and energy supply to oil companies. In oil production, there is a practice of using associated petroleum gas to generate electricity for field needs.

The well-known "Power plant" developed by the company "Capstone", and described in the work (STC Microturbine technology. Review and development status of modern low-power gas turbine plants. Http:), in the housing of which a gas generator is installed; in it, a gas turbine is used as a drive for mechanically interconnected units - an electric generator and a compressor, one is designed to generate electrical energy, and the other, respectively, to compress air. This power plant contains a set of associated petroleum gas purification devices before feeding it into the combustion chamber of the gas generator, as well as a recuperator and an electronic converter.

The disadvantage of this technical solution is the need for preliminary preparation of concomitant combustible gas filtration, separation, drying. This complicates the design of the installation, which requires qualified maintenance. A disadvantage of the known power plant is also the design complexity due to both the high frequency of rotation of the turbine rotor, the small passage sections of its flow part with a possible flow of heterogeneous combustion products, and the high frequency of the generated electric current by a high-speed permanent magnet generator (45,000 rpm and above) and, as a consequence, the need to use an electronic converter for issuing to an external network an alternating current with a frequency of 50 Hz, voltage of 230 and 400 V.

The well-known "Energy installation" (Small energy of OJSC "SKBT" VOLGA-BUSINESS Magazine No. 1 (197) 2011), in the housing of which there is a turbine, compressor, combustion chamber, recuperator, high-speed gearbox and electric generator. A rigid connection of a turbine, as a drive of an electric generator, through a high-speed gearbox with an electric generator, requires complex automatic control at variable operating conditions of a power plant. The installation provides generation and delivery to an external network of alternating current with a frequency of 50 Hz, voltage of 230 and 400 V.

A disadvantage of the known gas turbine installation is the complexity of its design, due to the presence of a high-speed gearbox necessary to match the high speed of the turbine, including in transition modes, with the low speed of a standard alternator with a frequency of 50 Hz (1000 or 1500 rpm).

The closest in technical essence to the claimed and taken as a prototype is the "Energy machine for implementing the method of utilization of crude associated petroleum gas" (Patent RU No. 2447363, publ. 10.04.2012, IPC F23G 5/00), comprising a casing, a blade machine, the payload unit in the form of an electric generator, a combustion chamber, elements for supplying atmospheric air, associated petroleum gas, while the casing is made in the form of a chimney, energetically isolated from the environment, acting as a recuperator, before heat guide through the wall of the working fluid by using its thermal conductivity.

A disadvantage of the known technical solution is the constructive complexity of matching, which reduces the efficiency of conversion into electrical energy of thermal energy of the flare process for the utilization of associated petroleum gas, due to the low thermal efficiency of a heat engine operating at low pressure values of the working fluid (oxidizing agent - air, fuel - associated petroleum gas), reducing the range of sustainable operation.

The technical task of the invention is to increase the efficiency of a power plant by increasing the thermal efficiency while maintaining a low pressure of one of the components of the fuel in the combustion chamber and simplicity of matching a high speed of a turbine with a low speed of a standard electric generator while simplifying the design as a whole and expanding the range sustainable work.

The technical result is achieved by the fact that in a power plant containing a body in the form of a chimney, energetically isolated from the environment, a spatula machine, with the ability to work in compressor mode, a turbine drive, an electric generator in the form of a payload unit, a combustion chamber, elements for supplying atmospheric air , elements for supplying fuel, such as associated petroleum gas, a high-temperature recuperator, a low-temperature recuperator is introduced and it is equipped, as an additional drive, with at least one air motor, the input of which is connected to the compressor outlet, and the air motor output is communicated through the combustion chamber and the cavity of the exhaust pipe with the atmosphere, and the low-temperature recuperator is located in the cavity of the exhaust pipe behind the high-temperature recuperator, while each air motor is connected to one electric generator, which is the only electric generator driven him.

Contributes to the achievement of the technical result and the fact that the input of the air motor is in communication with the output of the compressor through the cold path of the low-temperature recuperator.

It contributes to the achievement of the technical result by the fact that an ejector is introduced into it and its inputs, like a heat generator, are communicated with the output of the compressor and with the output of the low-temperature recuperator, the input to the ejector from the compressor being made active, and the entrance to the ejector from the low-temperature recuperator this ejector output is communicated with the heat network of the consumer of thermal energy.

New is:

An increase in the efficiency of a power plant is achieved by increasing the thermal efficiency while maintaining a low pressure of the fuel supply to the combustion chamber and the oxidizing agent in the form of high turbulence of the heated air stream after the turbine, as well as simplification of matching the high speed of the turbine with a low speed of standard an alternating current generator with a frequency of 50 Hz, a voltage of 230 and 400 V due to the introduction of an elastic coupling, i.e. by redistributing the air flows into the structural elements of the compressor turbine drive and electric generator drive, thereby expanding the range of stable operation while simplifying the installation as a whole. In a power plant, a stable operation mode is ensured with the possible simultaneous generation of thermal and electric types of energy, for example, in the winter season of the year.

The air heating network is relevant for the regions of the Far North, Siberia and the Far East, both as an emergency system in housing and communal services and as a stationary heating network.

The simplicity of operation and maintainability of the power plant is ensured by the parallel connection of air motors, i.e. communication with each other at the entrance through automation elements conventionally not shown on the graphic materials of the invention. It allows without disconnecting the operation of the power plant to connect, disconnect, switch in the mode of variable loads during operation and repair of additional power.

This innovative feature allows the use of a power plant for autonomous power supply of residential buildings, shopping centers, office buildings, swimming pools, hospitals, catering facilities.

To clarify the technical nature, consider figures 1-3.

In FIG. 1 shows the appearance of a power plant.

In FIG. 2 shows a diagram of a power plant in which an electric generator with a drive in the form of a pneumatic motor, the input of which is connected to the output of the compressor, which generates electrical energy.

In FIG. 3 shows a diagram of a power plant, in which an electric generator with a drive is presented, in the form of a pneumatic motor generating an electric and an ejector with inputs, like a thermal generator, connected to the compressor output and the output of a low-temperature recuperator generating thermal types of energies, where the figures indicate:

1 - power plant building;

2 - compressor;

3 - turbine;

4 - electric generator;

5 - a combustion chamber;

6 - air motor;

7 - high-temperature recuperator of the working fluid of the turbine;

8 - low-temperature recuperator of the working fluid of the air motor;

9 - elements for supplying atmospheric air;

10 - fuel supply elements;

11 - exhaust pipe;

12 - ejector.

The appearance of the power plant is shown schematically in the drawing of FIG. 1. It contains a housing 1, a turbocharger, consisting of a compressor 2 and a turbine 3, connected by a shaft. The generator 4 is located outside the high-temperature zone of the power plant. The combustion chamber 5 is located in the housing 1. The air motor 6 is mechanically connected to the electric generator 4. The high-temperature recuperator 7 is located in the housing 1 after the combustion chamber 5. Through the hot path, the high-temperature recuperator 7 is in communication with the combustion chamber 5 and with the atmosphere, respectively. On the cold path, the low-temperature recuperator 8 is communicated by air ducts with the output of the compressor 2 and with the input of the air motor 6, respectively. The output of the air motor 6 is in communication with the combustion chamber 5. On the hot path, the low-temperature recuperator 8 is in communication with the output of the combustion chamber 5 and with the atmosphere, respectively. The elements of the supply of atmospheric air 9 are mounted on the compressor 2. The elements of the supply of fuel 10 and the elements of automation are fixed on the housing 1, on the burner devices of the combustion chamber 5. The elements of automation and burner devices are not conventionally shown in the drawing. The low-temperature recuperator 8 is located in the cavity of the exhaust pipe 11 behind the high-temperature recuperator 7. The turbine drive of the compressor 2 and the drive of the electric generator 4 have a common gas connection through the air path and are arranged to redistribute the air flow between the drives, and the outputs of the turbine 3 and air motor 6 are in communication with the internal cavity combustion chambers 5.

The internal cavities of the hot path of the high-temperature recuperator 7 and the low-temperature recuperator 8 formed a flow part for the flow of high-temperature products from the combustion chamber 5 through the exhaust pipe 11 into the atmosphere. The input of the compressor 2 is in communication with the elements of the supply of atmospheric air 9, the output of the compressor 2 is connected to the input of the turbine 3 through a high-temperature heat exchanger 7 through a cold path, and the output of the turbine 3 is connected to the combustion chamber 5.

The air motor 6 is the only drive of the electric generator 4, and the number of air motors 6 and, accordingly, the electric generators 4 is not the only one, since it depends on the magnitude of the load.

In FIG. 2 and FIG. 3, arrows also show a flow diagram of a stream of atmospheric air, fuel, for example, crude petroleum gas supplied to the combustion chamber, and a working fluid obtained in the process of burning fuel in a heated turbulent air stream in a power plant.

The introduction of an ejector into a power plant allows, for example, in winter to obtain not only the most valuable type of electric energy from a portion of the thermal energy of the working fluid, but also to obtain an environmentally friendly form of thermal energy in the form of heated air for heating from the remaining portion of the thermal energy of the working fluid.

The air motor 6, being the only drive of the electric generator 4, is connected to the output of the compressor 2 by the input, and the output of the air motor 6 is connected through the combustion chamber 5 and the cavity of the exhaust pipe 11 to the atmosphere. The ejector 12 has inputs connected to the output of the compressor 2 and the output of the low-temperature recuperator 8, and the output of the ejector 12 is connected to the consumer of thermal energy in the form of heated air for heating, i.e. with a heating network of housing and communal services (housing and communal services). In the start-up mode, the electric generator 4 works as a starter, and the air motor 6 works as a compressor, being a starting device.

The power plant operates as follows.

The starting device spins the rotor of the compressor 2 and turbine 3. Through the fuel supply elements 10, automation elements mounted on the housing 1, fuel is supplied to the burner devices of the combustion chamber 5. Atmospheric air is compressed in the compressor 2.

Through the air supply elements 9 and the fuel supply elements 10, the compressed air after the compressor 2 together with the fuel is supplied to the combustion chamber 5, mixed and ignited by the ignition device located in the burner devices. The mixture of fuel and oxidizer burns in the combustion chamber, releasing a certain amount of heat. After starting up the combustion chamber 5, a stationary mode of particleless combustion is formed by applying a predetermined ratio of fuel and oxidizer components. The vertical arrangement of the combustion chamber 5 is preferred.

Compressor 2 compresses the air and directs it to the inlet of the cold duct of the high-temperature heat exchanger 7. Heated air in the high-temperature heat exchanger 7 (approximately up to a temperature of 800-850 degrees Celsius) enters the turbine 3 and then into the combustion chamber 5. The expansion work of the compressed in the compressor 2 and heated in a high-temperature air recuperator 7 in the turbine 3 is used to drive the compressor 2. Excessive thermal energy is used to direct either part of the compressed air in the compressor 2 or heated to a low temperature To the recuperator 8, parts of compressed air to the inlet of the air motor 6 to work as an additional drive of the electric generator 4. As a starting device when starting the power plant, the electric generator 4 itself can be used, which switch and it can work in starter mode, and the air motor 6 works in this case in compressor mode.

Fuel through the fuel supply elements 10 and the atmospheric air supply elements 9 is supplied to the combustion chamber 5 and burned therein in the medium of heated (approximately to a temperature of 400-420 degrees Celsius) air, releasing a certain amount of heat.

The expansion work of the compressed air in the compressor 2 and heated in the high-temperature recuperator 7 of the air in the turbine 3 is used to drive the compressor 2, providing its high speed. The excess part of the expansion work in the turbine 3 compared to the air compression work in the compressor 2 is realized by compressing more air than passes through the turbine. The excess part of the compressed air is directed to the low-temperature recuperator 8 and heated (approximately up to a temperature of 350-370 degrees Celsius) and is then used to work the expansion in the air motor 6 as the drive of the electric generator 4. The expansion work of the excess part of the compressed in the compressor 2 and heated in the low-temperature recuperator 8 of air in the air motor 6 provides a low speed of a standard electric generator 4 in alternating current mode with an electric frequency of 50 Hz, voltage of 230 and 400 V .

The air after the air motor 6 is directed into the internal cavity of the combustion chamber 5, which participates in the combustion process together with the air after expansion in the turbine 3, and then in the form of combustion products (approximately at a temperature of 950-1000 degrees Celsius) is directed along the flow part of the hot ducts of high temperature and low temperature recuperators.

Claims (3)

1. Power plant, comprising a casing in the form of a chimney, energetically isolated from the environment, a blade machine, with the ability to work in compressor mode, a turbine drive, an electric generator in the form of a payload unit, a combustion chamber, elements for supplying atmospheric air, elements for supplying fuel, for example associated petroleum gas, a high-temperature recuperator, characterized in that a low-temperature recuperator is introduced into it, and it is equipped with at least one a pneumatic motor, the input of which is communicated with the compressor output, and the pneumatic motor output is communicated through the combustion chamber and the cavity of the exhaust pipe with the atmosphere, and the low-temperature recuperator is located in the cavity of the exhaust pipe behind the high-temperature recuperator, with each air motor connected to one electric generator, which is its only drive. 2. The power plant according to claim 1, characterized in that the input of the air motor is in communication with the output of the compressor through the cold path of the low-temperature recuperator. 3. The power plant according to claim 1, characterized in that an ejector is introduced into it and its inputs, like a heat generator, are communicated with the output of the compressor and with the output of the low-temperature recuperator, and the input to the ejector from the compressor is made active, and the entrance to the ejector from the low-temperature the recuperator is made passive, while the ejector output is in communication with the heat network of the heat energy consumer.

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