RU2626182C1 - System of generation of electric and thermal energy - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is referred to systems intended for electric energy generation to supply oil- producing machinery and facilities using associated gas as an energy carrier in order to ensure auxiliaries of plants of mineral resources sector located far from the operating power supply systems connected to the united power grid. The electric and heat energy generation system is equipped with two isolated circuits, a steam generation system, a first and a second bus section with a sectional switch, a synchronisation unit, first and second passive filters, and also an active filter.

EFFECT: invention makes it possible to increase the efficiency of the power plant operation in parallel with the network by filtering the higher harmonic components of the current produced by the active filter and synchronising the phase current through the synchronizing device, and also using two isolated energy circulation circuits in the exhaust gas utilisation unit.

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Description

The invention relates to electrical engineering, heat and electricity, and in particular to cogeneration systems for generating electric and thermal energy for energy supply of machines and complexes of oil and gas production facilities using associated petroleum gas as an energy carrier and for providing own needs of enterprises of the mineral resource complex located far from existing centralized power supply systems without communication with a single power system.

Known cogeneration gas turbine power plant (patent RU No. 2528214, publ. 05.27.2014), containing low and high pressure compressors, a combustion chamber, a high pressure gas turbine and a low pressure gas turbine having a gas connection, a heating device and a main electric generator connected to a high pressure gas turbine and used as a payload. The output of the low pressure compressor is connected to the input of the high pressure compressor. The heating device is installed between gas turbines, equipped with an internal hot channel in which a moving heat carrier is located, which is combustion products partially spent on a high-pressure gas turbine, as well as a cold channel with another moving heat carrier inside, which removes the heat exchange between the hot and cold channels inside the heating device thermal energy for its use outside the gas turbine power plant. In the cogeneration gas turbine power plant, a heat exchange device is additionally installed, containing hot and cold channels interacting with each other through heat exchange. The inlet of the hot channel of the heat exchanger is connected to the outlet of the high pressure gas turbine, and the outlet of the hot channel of the heat exchanger is connected to the inlet of the hot channel of the heating device. Partially exhausted combustion products from a high-pressure gas turbine are used as a moving heat carrier of the hot channel of the heat exchanger. The input of the cold channel of the heat exchanger is connected to the outlet of the high pressure compressor, and the output of the cold channel of the heat exchanger is connected to the input of the combustion chamber. As a moving coolant of a cold channel of a heat exchanger, a gaseous mixture containing an oxidizing agent coming from a high-pressure compressor was used. The heating device is made with adjustable heat removal. An additional electric generator connected as a payload is connected to the low pressure gas turbine. The invention is aimed at providing regulation of the cogeneration mode, that is, the amount of generated thermal and electrical energy, and at increasing the efficiency.

The disadvantage of the installation is the increase in its overall dimensions due to the need to use compressors and turbines of high and low pressure and the associated channels for the circulation of hot and cold coolants, as well as an automated distribution system for the output parameters of the installation.

Known electric power installation (patent RU No. 2363090, publ. 07.27.2009), equipped with a starting source of electricity and containing an internal combustion engine, mechanically connected to an electric machine with a rotor, for example, with permanent magnets, which when starting the installation works as an engine, and in working mode - like a generator. The stator windings of an electric machine through a three-phase bridge rectifier are connected to DC buses of a three-phase bridge inverter on semiconductor switches connected to a control system that implements the "generation" and "start" modes. The unit is equipped with contactors, in each phase having one input and two output terminals. The input terminals are connected to the power outputs of the inverter, and one of the output terminals of each phase is connected to the stator windings of the electric machine. The other output terminal is connected directly or through the filter unit to the load, so that in the "start" mode the inverter is connected to the stator windings of the electric machine, and in the "generation" mode it is connected to the loads.

The disadvantage is the incomplete use of an additional source of electricity needed to start the electric machine, as well as the use of an additional filter, which leads to an increase in the dimensions of the installation, and a decrease in the reliability of the power supply system.

A known system for generating electricity (patent RU No. 2480602, publ. 04/27/2013), containing a motor in which the oxidizing agent is air, mechanically connected to a movable shaft. The engine is designed to produce a mixture of air and fuel and burn the mixture so that the mixture expands and creates mechanical energy, which is used to propel the shaft. It contains a fuel system connected to the engine and designed to supply fuel to the engine, while the fuel system provides a change in fuel consumption on the engine in response to a fuel supply control signal. The system further comprises a heat exchanger for receiving compressed air from the compressor device and exhaust gases from the power device and for exchanging heat from exhaust gases to compressed air to provide preheating of the compressed air before combustion in the power device. The heat exchanger also includes a sensor for measuring a variable indicating the temperature of the exhaust gases entering the heat exchanger, wherein the controller is connected to the sensor associated with the heat exchanger and is used to control the air flow in the engine to maintain the temperature of the exhaust gases entering the heat exchanger, below the set maximum temperature.

The disadvantages are the low reliability of the double energy conversion unit, which leads to a deterioration in the operation of protection and automation devices, as well as the incomplete use of the high-temperature potential of the exhaust gases at the outlet of the recuperator system.

Known multi-stage turbogenerator system (patent RU No. 2361102, publ. 07/10/2009), adopted as a prototype. The invention relates to energy. A system is proposed for generating electric energy driven by a multi-circuit gas turbine engine, which includes at least the first and second stages. The first stage contains a turbine and a compressor mounted on the first shaft, the second stage has at least a turbine that is mounted on the second shaft and is not mechanically connected to the first shaft. A main generator is connected to one of the cascades, and an auxiliary generator-motor is also connected to one of the cascades. To control the operation of the engine, the speed control of each of the generators is used. The auxiliary generator-engine can operate either in the generation mode, taking energy from its cascade, or in the engine mode, transmitting energy to its cascade. The invention allows to optimize the efficiency of the engine by controlling the air flow through the engine in such a way that the ratio of the components of the air-fuel mixture is controlled to maintain the high peak temperature communicated by the working fluid in the engine.

The disadvantages are the lack of synchronization of the system’s operation in parallel with the network due to the lack of filter-compensating devices in the installation, as well as the inefficient use of the temperature potential of the primary energy carrier in the heat exchange circuit.

The technical result is to increase the efficiency of the power plant in parallel with the network by compensating for the higher harmonic components of the generated voltage by using passive and active filters and phase-locked current through a synchronization device, as well as using two isolated energy carrier circuits in the exhaust gas recovery unit.

The technical result is achieved by the fact that the system for generating electric and thermal energy, comprising a compressor, a combustion chamber and a turbine of a gas turbine installation installed on the first shaft, a heat exchanger in communication with the compressor of the gas turbine installation, a first generator connected to a power electronics unit including an inverter and a storage capacitor , an air temperature sensor connected to the controller, a second turbine not mechanically connected to the first shaft, mounted on the second shaft of the second generator p connected to the power electronics unit, the temperature sensor of the exhaust gases connected to the controller is additionally equipped with a steam generation system connected to a heat exchanger to remove part of the high-temperature potential of the primary energy carrier, and a second turbine using the residual potential of the primary energy carrier, the first and second section of tires with sectional switch, synchronization unit, first and second passive filters, and also an active filter, while the power electronics unit is equipped with a second the inverter and the second storage capacitor, and the rectifiers in the power electronics block are made active, and the output of the first active rectifier is connected through the first capacitor to the input of the first inverter, the output of the second active rectifier is connected through the second capacitor to the input of the second inverter, and the output of the first inverter through the first passive the filter is connected to the first bus section, the output of the second inverter through the second passive filter is connected to the second bus section, between the first and second bus sections anovlen section switch, and between the first section and the tire section switch connected sync block.

The energy generation system is illustrated by the following figure:

FIG. 1 is a diagram of a device where:

1 - compressor of a gas turbine installation;

2 - movable shaft;

3 - turbine of a gas turbine installation;

4 - combustion chamber;

5 - fuel metering valve;

6 - gas turbine installation;

7 - the first generator of electrical energy;

8 - steam generation system;

9 - steam pipe steam turbine installation;

10 - steam turbine;

11 - steam turbine installation;

12 - shaft;

13 - the second generator of electrical energy;

14 - air flow temperature sensor;

15 - exhaust gas temperature sensor;

16 - heat exchanger;

17 - active rectifier of the first generator;

18 - active rectifier of the second generator;

19 - storage capacitor of the first generator;

20 - storage capacitor of the second generator;

21 - autonomous inverter of the first generator;

22 - autonomous inverter of the second generator;

23 - power electronics unit;

24 - passive filter of the first generator;

25 - passive filter of the second generator;

26 - section switch

27 - block synchronization;

28 - load sensor;

29 - active filter;

30 - control system controller;

31 - the first section of tires;

32 - the second section of tires;

33 - the first output circuit;

34 - second output circuit.

The energy generation system consists of 1 compressor of a gas turbine installation, 3 turbines of a gas turbine installation mechanically connected by a movable shaft 2 with a first electric energy generator 7, 5 — a fuel metering valve connected to the combustion chamber 4. The system also contains temperature sensors for air and exhaust gases 14 and 15, respectively, a heat exchanger 16 connected to the gas turbine unit 6 through the first output circuit 33, a steam generation system 8 connected to the heat exchanger 16 through the second output tour 34. The steam generation system 8 is connected by steam pipelines 9, with a steam turbine 10 with a steam turbine installation 11 connected by a shaft 12 to a second electric energy generator 13. The power electronics block 23 is made in the form of active rectifiers of the first and second generators 17 and 18 connected to the generators 7 and 13, storage capacitors of the first and second generators 19 and 20, autonomous inverters of the first and second generators 21 and 22. Active rectifiers 17 and 18, built on fully controllable transistors, are connected through the accumulator capacitors 19 and 20 with autonomous inverters 21 and 22. Autonomous inverters 21 and 22 are also made on fully controllable transistors and are connected to the first 31 and second 32 bus sections through passive filters of the first and second generators 24 and 25, connected by a section switch 26. Block synchronization 27 is connected in parallel to the bus sections and is used to synchronize the phase voltage generated by the generators before connecting the load (not shown). An active filter 29 is also connected to the output of the synchronization unit. The signals of the temperature sensors 14 and 15, the load sensor 28, the power electronics unit 23, the fuel metering valve 5, the heat exchanger 16 are sent to the controller of the control system 30, which controls the operation of the system nodes.

Temperature sensors 14 and 15 associated with the combustion chamber 4 and the heat exchanger 16 are designed to measure a variable indicating the temperature of the air before it is supplied to the combustion chamber and the temperature of the exhaust gases before they are fed to the heat exchanger, while the controller of the control system 30 is connected to the fuel metering valve 5 and regulates the fuel consumption of the gas turbine unit 6 in order to maintain the temperature in the range of permissible values.

The system operates as follows. The compressor of the gas turbine unit 1 draws in air from the environment, compresses it and directs it through the first output circuit 33, the heat exchanger 16 and the air temperature sensor 14 into the combustion chamber 4. Fuel is supplied through the fuel metering valve 5 to the combustion chamber 4, where it is mixed with heated air and burned. The air-fuel mixture is introduced into the turbine of the gas turbine unit 3, where it expands and creates mechanical energy that drives the shaft 2, the rotary compressor of the gas turbine unit 1 and the first electric energy generator 7. The exhaust gases of the gas turbine unit 6 pass through a pipeline through a heat exchanger 16 equipped with a sensor temperature measurement 15, to transfer heat to the compressed air leaving the compressor 1. Part of the exhaust gas is disposed of in a first closed loop for transferring heat to the circulating in the heat carrier, which is used to heat technological objects. The remainder of the exhaust gases is sent to the steam generation system 8 through the second closed loop output 34 of the steam turbine unit 11, where their thermal potential is transferred to the intermediate coolant, which acts as a low-boiling medium, and steam is formed. The generated steam flows through a steam line 9 to a steam turbine 10, rotating by means of a shaft 12 a second electric energy generator 13. The action of the steam turbine 10 causes the generator 13 to generate alternating electric current.

The generator 7, under the influence of a turbine of a gas turbine installation 3, also generates an alternating electric current. The alternating electric current from the generators 7 and 13 is converted by the power electronics unit 23 to obtain an alternating output current and voltage with a predetermined fixed frequency before synchronization and applying to the load. The alternating electric current from the generators 7 and 13 is converted to direct using active rectifiers 17 and 18, respectively, the suppression of voltage ripples is carried out by storage capacitors 19 and 20, the conversion of direct current to alternating current is carried out by autonomous inverters 21 and 22, the higher harmonic components of which are first compensated by passive filters 24 and 25, then the phase voltage is synchronized in the synchronization unit 27, then the final filtering of the residual higher harmonics ble components via the active filter 29, whereupon the voltage supplied to the load. The sectional switch 26 serves to isolate the sections 31 and 32 from each other in the case of using only one generator and utilization of the entire temperature potential of the exhaust gases in the primary circuit of the disposal unit. The load sensor 28 transmits the load parameters to the controller of the control system 30.

As a result, generators 7 and 13 operate in parallel, providing a load (not shown) with electricity.

The use of the energy generation system allows to reduce the higher harmonic components of current and voltage, as well as to ensure the effective conversion of the primary energy source into electrical and thermal energy, for uninterrupted power supply to remote oil production areas, enterprises of the mineral resource complex.

Claims (1)

An electric and thermal energy generation system comprising a compressor, a combustion chamber and a turbine of a gas turbine installation mounted on a first shaft, a heat exchanger in communication with a compressor of a gas turbine installation, a first generator connected to a power electronics unit including an inverter and a storage capacitor, an air temperature sensor connected with a controller, a second turbine not mechanically connected to the first shaft, a second generator mounted on the second shaft, connected to the power electronics unit an exhaust gas temperature sensor connected to a controller, characterized in that the system is further provided with a steam generation system connected to a heat exchanger for removing part of the high-temperature potential of the primary energy carrier, and a second turbine using the residual potential of the primary energy carrier, the first and second tire section with a section switch, synchronization unit, the first and second passive filters, and also an active filter, while the power electronics unit is equipped with a second inverter and the second storage capacitor, and the rectifiers in the power electronics block are made active, with the output of the first active rectifier connected through the first capacitor to the input of the first inverter, the output of the second active rectifier connected through the second capacitor to the input of the second inverter, and the output of the first inverter through the first passive filter connected with the first bus section, the output of the second inverter through the second passive filter is connected to the second bus section, a section is installed between the first and second bus sections onny switch, and between the first section and the tire section switch connected sync block.

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