RU2374472C1 - Method and device to start gas turbine plant - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed device comprises turbine motor, compressor, combustion chamber, air intake and system to feed compressed air into combustion chamber. Air intake incorporates check valve for it to let air inside the compressor from outside and prohibits back flow, when starting gas is forced into combustion chamber. Note that proposed device comprises also the system that feeds compressed air into gap between aforesaid check valve and compressor. Starting gas is fed directly into combustion chamber and/or on turbomachine rotor blades. In accelerating turbine, gas is forced under pressure into chamber between check valve and turbine plant compressor.

EFFECT: accelerated starting.

5 cl, 4 dwg

Description

The invention is intended for start-up of gas turbine units by the method of pressurized gas pressurization (non-starter) and can be used, for example, as a means of starting a gas turbine as a long-term backup power source, capable of quickly and within the necessary time providing independent power to emergency operation systems of facilities (hospitals, nuclear power plants) and devices (engines, appliances).

State of the art

It is known from the prior art that diesel generators are used as backup power sources, including and using air launch. Due to the greater reliability of start-up and better economic characteristics, the proposed solution has significant advantages over those currently used as backup diesel power plants, as well as the systems used to start them.

BACKGROUND OF THE INVENTION A METHOD FOR COOLING AND WITHDRAWAL FROM A POWER UNIT OF A NUCLEAR POWER PLANT OR NUCLEAR POWER INSTALLATION OF ANOTHER PURPOSE WITH A FULL DISCHARGE AND A DEVICE FOR ITS IMPLEMENTATION. The invention provides for an accelerated shutdown of the turbogenerator with full blackout due to the use of residual heat from the reactor and the accumulated thermal energy to generate water vapor and trigger it in a specially designed additional steam turbine unit. An additional steam turbine installation, receiving steam from the main steam pipeline, provides the supply of the required feed water flow rate to the steam generating unit of the power unit through standard oil flow controllers to the bearings of a standard turbogenerator. At the same time, the rotor of a standard turbogenerator is accelerated to an electrodynamic stop using an electrodynamic braking system (general coasting mode). In this case, electric energy from the generator is diverted to a ballast load device with active resistance. The excitation winding of a standard coastal generator, as well as a control, monitoring and recording system, is supplied from a DC generator located on the same shaft as the turbine of a steam turbine installation. When the power unit is completely de-energized, it is possible to remove the peak of stopping heat generation, partially cool down and stop the turbogenerator during the device’s operation on the thermal run-down of the power unit, and increase the operational reliability and safety of the power unit. There is enough time to find a failure and restore regular power supply to the power unit.

This solution involves the use of an additional steam turbine as a temporary source of backup (emergency) power, receiving steam from the same source as the main turbine of the nuclear power plant generator, and using this energy to stop, dampen and temporarily power the station. Obviously, this solution is only temporary and cannot serve as a means of long-term power supply of nuclear power plants in case of emergency blackout of the power unit. The inventive device, on the contrary, involves a method of accelerating the start of a turbogenerator, which, if used as a backup power source, is able to quickly and within the necessary time provide independent power to emergency operation systems of nuclear power plants.

The prior art solution is known [2]. This solution differs from the claimed device in that in order to accelerate the start of the turbogenerator at the start, the generator part of the installation operates in the electric motor mode and thereby spins the turbine, which is achieved by the presence of a special control system providing inverter operation of the generator (in the “motor” mode). After reaching the required modes, the turbine is ignited and launched, and the generator part is disconnected from the inverter and starts to work as a generator of electric power driven by a turbine in normal mode. In the claimed device, the source of accelerated start-up is compressed air, it also serves to cool the turbine until it reaches its normal mode.

The prior art solution is known [3]. This solution differs from the claimed device in that in order to accelerate the start of the turbogenerator at the start, the generator part of the installation operates in the electric motor mode and thereby spins the turbine, which is achieved by the presence of a special control system providing inverter operation of the generator (in the “motor” mode). After reaching the required modes, the turbine is ignited and launched, and the generator part is disconnected from the inverter and starts to work as a generator of electric power driven by a turbine in normal mode. To untwist the generator in the “motor” operating mode, previously stored electrical energy is used, which is consumed at the time of start-up, and then resumes in normal operation. In the claimed device, the source of the accelerated start-up is compressed air, it can also serve for the purpose of cooling the turbine until it enters normal operation and for the formation of the fuel mixture during the ignition, acceleration, warm-up and load acceptance of the turbine unit.

The prior art solutions are known [4, 5]. Their difference from the claimed device is the purpose for achieving a technical result, which in solutions [4, 5] is listed as a method of reliable start-up of a turbogenerator. The claimed device is distinguished by its solutions in that the goal is to accelerate the launch of the turbogenerator unit (TSU), which uses an external energy source in the form of a reserve of compressed gas. At the initial stage, compressed gas acts as a means of spinning the turbine, while the same gas (depending on the type of gas used) provides ignition of the fuel in the combustion chamber, and it, in the early stages of start-up, serves the purpose of cooling the turbine. In order to prevent energy losses of the starting compressed gas at the start-up stage, the compressed gas is simultaneously supplied to the combustion chamber and to the air intake, while a check valve is installed at the main inlet of the air intake to prevent the outgoing start gas from flowing out. The non-return valve opens upon command of the control system after the turbine enters the design mode. The amount of fuel supplied at the start-up phase is determined on the basis of the requirements for the fastest start-up and acceptance of the TSU load, provided that the thermal regime is maintained.

The closest analogue is the source [6, 8], which describes how to start a gas turbine unit using compressed air (pressurization). As follows from the literature, the well-known supercharged start-up is carried out by supplying compressed air either directly to the air intake of the turbine unit, or directly to the rotor of the turbo engine. In the first case (when supplied to the air intake), the rotor spins up with large losses of air energy due to the low efficiency of the compressor part of the turbine unit at low speeds, which does not allow it to be used to start high-power turbines or to ensure a high starting speed. In the second case (when applying directly to the rotor of the turbomotor), the energy of the compressed gas is used inefficiently due to the inevitable outflow of the supplied air through the compressor and the air intake to the outside, which counteracts the spinning of the rotor of the turbomotor, reduces the efficiency and does not allow for fast start-up. In common with the prototype is the use of boost to start the turbine unit and the fact that the starting gas (compressed air) is supplied directly to the rotor of the turbo engine (either into the combustion chamber, or tangentially directly to the rotor blades).

The technical result of the claimed invention is to increase the efficiency of using compressed starting gas for starting a turbine unit, as a result it is possible to accelerate the start of units, reduce the amount of starting air, the possibility of using a supercharged start for high power units, fewer systems and equipment needed to start and control turbine units. Also, in the case of using compressed air or other gases capable of forming a fuel mixture with the unit's fuel as a starting gas, it becomes possible to supply fuel, ignite, heat up and accept the load by the turbine due to the supplied gas, without waiting for the rotation of the turbine rotor to provide the necessary flow through the air intake.

Brief Description of the Drawings

Figure 1 shows a structural diagram of a device that implements the method, where 1 is a turbo engine, 2 is a compressor, 3 is a combustion chamber, 4 is a check valve, 5 is a system for supplying starting compressed gas to the combustion chamber (option is on the blades of the turbine rotor), 6 - system for supplying compressed gas to the space between the non-return valve and the compressor, 7 - air supply channel for the main mode of operation of the unit (air intake), 8 - supply of compressed air to the combustion chamber in the main mode, 9 - fuel supply, 10 - supply to the turbo engine compressed gas unit in start-up mode as well as combustion products in the main mode (self-propelled), 11 - supply of compressed starting gas to the combustion chamber (option - on the blades of the rotor of a turbo engine) during the start-up period, 12 - supply of compressed gas for the start-up period to prevent the effect of pneumatic braking.

Figure 2 shows an example of a structural device for starting a turbine unit, where 13 is a nozzle apparatus, 14 is an exhaust pipe, 15 is a starting gas supply zone.

Figure 3 shows the start control algorithm in operation using gases that both generate and do not form a fuel mixture unit with fuel.

Figure 4 shows the start control algorithm in operation using gases capable of forming a fuel mixture with the fuel of the unit.

SUMMARY OF THE INVENTION

The claimed technical result is achieved due to the fact that the method of starting a gas turbine unit is characterized by the supply of compressed gas directly to the rotor of the turbo engine or into the combustion chamber, or tangentially directly to the rotor blades, characterized in that (see Figure 1 and Figure 2) the main air supply channel (7) in the working turbine unit (air intake) is equipped with a check valve (4), and the starting gas (11) is supplied directly to the combustion chamber (3) and / or to the blades of the rotor of the turbomachine, and for the period of the tour acceleration under pressure the gas unit is fed into the zone between the check valve (4) and the compressor (2) of the turbine unit.

The gas supply (12) under pressure for the period of acceleration of the turbine unit into the area between the check valve (4) and the compressor (2) of the turbine unit prevents the occurrence of pneumatic braking effect during the period of acceleration of the turbine unit.

The supplied starting gas can be used as a component of the fuel mixture for acceleration, ignition, heating and acceptance of the load by the turbine.

A device (see FIG. 1 and FIG. 2) for starting a gas turbine unit comprises a turbo engine (1), a compressor (2), a combustion chamber (3), an air intake (7), a system for supplying starting compressed gas to the combustion chamber (5). A distinctive feature of the device is that it contains a check valve (4) mounted on the air intake (7) in such a way that it passes air flow from the outside into the compressor (turbine unit) and does not allow reverse movement when the starting gas is supplied to the combustion chamber The device also includes a compressed gas supply system (6) in the space between the check valve (4) and the compressor (2).

The gas supply (12) under pressure for the period of acceleration of the turbine unit into the area between the check valve (4) and the compressor (2) of the turbine unit prevents the occurrence of pneumatic braking effect during the period of acceleration of the turbine unit.

To control the pressure and reduce the unproductive start-up gas flow, a diffuser (not shown) with a controlled cross-section is installed at the turbine exit (in the path of the outgoing gases), and at the initial phase of acceleration, the diffuser is closed as much as possible (passage cross-section is minimal) to reduce air flow when stationary or slowly rotating rotor. As the rotor accelerates, the diffuser is opened, the flow area increases, and, accordingly, the volume of starting gas passing through the turbine increases.

To overcome dry friction at the moment of starting the rotor, the specified device is used in combination with standard shaft-turning mechanisms, including and pneumatic action.

For a general increase in the efficiency of starting up a turbine unit, it is possible to use the described device in combination with known starting methods, such as spinning a turbine rotor using an electric motor or an electric generator operating in a motor mode.

The claimed device solves the problem of accelerating the rotor of a gas turbine unit with compressed gas from the moment the rotor of the turbo motor starts moving (1) until the turbine unit reaches the main mode of operation (self-propelled and the output of useful power). As a source of compressed gas can be used cylinders with its preliminary stock, an external compressor or other turbine unit of the corresponding capacity. According to the claimed device, the compressed gas is supplied (for example, using the system (5)) directly to the combustion chamber (3) of the unit (to the turbo engine rotor) and ensures its unwinding to the required starting values. To increase the efficiency of using the energy of compressed gas and accelerating the acceleration of the rotor of the turbo engine (1), the channel of the main air supply (air intake) (7) is blocked by the check valve (4) for the time of acceleration, which eliminates the outflow of starting gas through the air intake. To prevent the effect of pneumatic braking in the space between the non-return valve (4) and the compressor (2) during the acceleration period, compressed gas (12) is also provided in this space, for example, bypassing from the system (5) or through a controlled valve independent of the system ( 5) source. The supply of starting gas under pressure simultaneously to the combustion chamber (alternatively to the rotor blades) and to the space between the closed non-return valve and compressor blades ensures equal pressures before and after the compressor, so that the effect of pneumatic braking does not occur and the energy of the starting gas is not spent on overcoming it .

Since the entire volume of compressed gas supplied to untwist the rotor of the turbomotor passes through the rotor blades and the output section, all the energy of the compressed gas is spent solely on creating torque on the rotor blades. In this way, an increase in the efficiency of using compressed starting gas to start the turbine unit is achieved, and as a result, it becomes possible to accelerate the launch of turbine units, reduce the amount of starting air, apply supercharged launch for large power units, reduce the number of systems and equipment used to start and control turbine units.

In the case of using compressed air or other gases that can form a fuel mixture with the unit fuel as a starting gas, it becomes possible to supply fuel and ignite the turbine due to the supplied gas, without waiting for the rotation of the turbine rotor to provide the necessary flow through the air intake. In this case, the starting gas can provide the full (with the non-return valve closed) or partial (with the open) volume necessary for the formation of the fuel mixture and for ensuring the combustion mode. In this case, the non-return valve blocking the air intake in the start-up mode can be opened either by force from the control system signal or automatically, after the corresponding vacuum appears as a result of rotation of the compressor of the turbine unit. The start of the gas turbine unit is as follows. At the start signal, compressed gas is supplied to the combustion chamber (3) (option - to the blades of the turbo engine rotor) and simultaneously to the space between the closed non-return valve (4) and the compressor (2). The energy of the compressed gas ensures the spinning of the rotor of the turbomotor (1) and its output to a mode that allows the supply of fuel and ignition of the combustible mixture. After ignition and torch production, the combustion products begin to be used to rotate the turbo engine, and, depending on the control system, the supply of starting gas is completely stopped or the unit continues to work using the starting compressed gas as a component of the fuel mixture. Upon receipt of the appropriate control signals, the check valve (4) opens; the start gas supply to the space between the non-return valve (4) and the compressor (2) is regulated and stops; the starting gas supply to the combustion chamber (11) is stopped; the unit enters the basic mode of operation (self-propelled); the unit is heated and load is taken.

Depending on the power of the units, the type and volume of the starting gas used, the type of tasks to be solved, the start control can be carried out in the operating mode using gases that both form and do not form the fuel mixture aggregate with the fuel (see the algorithm diagram in Figure 3) or operating mode using gases capable of forming a fuel mixture with the fuel of the unit (see the algorithm diagram in Figure 4).

Information sources

1. Patent RU 2162621 from 1998.01.19, cl. IPC G21C 15/18, G21D 3/00.

2. Patent EP 0901218 from 1999-03-10, cl. IPC Н02Р 9/08; H2P 9/04; H2P 9/08; Н02Р 9/04.

3. Patent EP 0963035 from 1999-12-08, cl. IPC F02C 7/268; H2P 9/08; F02C 7/26; Н02Р 9/08.

4. Patent US 2003056522 from 2003-03-27, cl. IPC F02C 7/26; F02C 3/00.

5. Patent WO 03014551 from 2003-02-20, cl. IPC F01D 17/20; F01D 19/00; F02C 7/224; F02C 7/26; F02C 7/268; F01D 17/00; F01D 19/00; F02C 7/22; F02C 7/26.

6. V.I. Daineko. "Analysis of the main technical characteristics of the start-up of a gas turbine with supercharging", Society "Knowledge", Ukraine, 1991

7. L.M. Voronin. "Features of the design and construction of nuclear power plants." M .: Atomizdat, 1980.

8. V.I. Daineko. "Improving the means of launching gas turbine plants is an important factor in increasing their efficiency." Society "Knowledge", USSR. 1983.

Claims (5)

1. The method of starting a gas turbine unit, characterized by the supply of compressed gas directly to the rotor of the turbo engine, or to the combustion chamber, or tangentially directly to the rotor blades, characterized in that a check valve is installed on the main air supply channel to the working turbine unit (air intake), and the starting gas is supplied directly to the combustion chamber and / or to the blades of the rotor of the turbomachine, and during the period of acceleration of the turbine unit, gas under pressure is supplied to the zone between the check valve and compressor urban unit. 2. The method of starting a gas turbine unit according to claim 1, characterized in that a diffuser with a controlled cross-section is installed at the outlet of the turbine in the path of the exhaust gases, and at the initial phase of acceleration in the diffuser, the passage section is closed to a minimum, and as the rotor accelerates, the diffuser is opened. 3. The method of starting a gas turbine unit according to claim 1 or 2, characterized in that the supplied starting gas is used as a component of the fuel mixture for acceleration, ignition, heating and acceptance of the load by the turbine. 4. A device for starting a gas turbine unit containing a turbo engine, a compressor, a combustion chamber, an air intake, a compressed gas supply system to the combustion chamber, characterized in that it comprises a check valve mounted on the air intake so that it allows air to flow from the outside into the compressor , and does not allow reverse movement when the starting gas is supplied to the combustion chamber, the device also includes a system for supplying compressed gas to the space between the check valve and the compressor. 5. The device for starting a gas turbine unit according to claim 4, characterized in that it has a diffuser with a controlled cross-section at the outlet of the turbine in the path of the exhaust gases.

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