JP2017180169A - Auxiliary mechanism for exhaust gas turbine supercharger, power generation facility including auxiliary mechanism and control method of auxiliary mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small auxiliary mechanism capable of assisting an exhaust gas turbine supercharger right after activation of an internal combustion engine.SOLUTION: In a power generation facility operating in occurrence of power failure and including an internal combustion engine 1 and a dynamo, an auxiliary mechanism configured to assist rotation of an exhaust gas turbine supercharger 4 for supplying compressed gas to the internal combustion engine 1 includes an air motor 11 connected to a turbine 5 of the exhaust gas turbine supercharger 4 and a rotational shaft 7 of a compressor 6, and a compressed gas tank 3 as a supply source configured to supply compressed gas to the air motor 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power generation facility including an internal combustion engine and a generator, an auxiliary mechanism for assisting rotation of an exhaust gas turbocharger that supplies compressed gas to the internal combustion engine, a power generation facility including the auxiliary mechanism, and an auxiliary mechanism. Relates to the control method.

  Facilities such as office buildings, factories, and hospitals have their own power generation equipment so that the operation of the facilities can be sustained even if a power failure occurs.

  Such a power generation facility includes an internal combustion engine such as a gas engine and a generator, and is configured to operate the internal combustion engine when a power failure occurs and to cause the generator to generate power using the operating power. An internal combustion engine is equipped with an exhaust gas turbine supercharger to save energy, and cogeneration to obtain hot water and steam for use in a facility using exhaust heat of the internal combustion engine is achieved.

  For example, as in Patent Document 1, an exhaust gas turbine supercharger includes a turbine and a compressor on the same axis, and uses the energy (dynamic pressure, static pressure, and thermal energy) of the exhaust gas of the internal combustion engine to operate the turbine. A configuration is disclosed in which a compressor is operated by the rotation force to increase the density of the supply gas to the internal combustion engine, thereby sending more oxygen to the combustion chamber and obtaining higher combustion energy. An intercooler, a throttle valve, and the like are appropriately provided between the compressor and the air supply port of the internal combustion engine.

  However, since such an internal combustion engine obtains a predetermined output by increasing the density of the supply gas to the internal combustion engine by an exhaust gas turbine supercharger, the amount of exhaust gas is small just after the start of the internal combustion engine. In the low load region, the exhaust gas turbocharger does not function sufficiently, and there is a possibility that the engine speed may be fluctuated or the internal combustion engine may be abnormally stopped due to a transient load application.

  Therefore, the exhaust gas turbine supercharger is equipped with an electric motor, and immediately after the internal combustion engine is started, the electric motor assists the rotation of the turbine (and the compressor) to increase the density of the supply gas in the low load region where the amount of exhaust gas is small. This stabilizes the behavior immediately after the start of the internal combustion engine.

JP 2000-257510 A

  However, the electric motor for assisting the rotation of the turbine is large and the power generation facility is enlarged because a separate storage battery and electric wiring are required. Moreover, when the electric power generated by the power generation facility is used for driving the electric motor, there is a problem that the substantial power generation efficiency of the entire cogeneration system is lowered.

  The present invention has been made in view of the above circumstances, and is a small auxiliary mechanism capable of assisting an exhaust gas turbine supercharger immediately after startup of an internal combustion engine, a power generation facility including the auxiliary mechanism, and a method for controlling the auxiliary mechanism. The purpose is to provide.

  In order to achieve the above-described object, the auxiliary mechanism according to the present invention is characterized in that, in a power generation facility including an internal combustion engine and a generator, rotation of an exhaust gas turbine supercharger that supplies compressed gas to the internal combustion engine. And an air motor connected to the turbine of the exhaust gas turbine supercharger and a rotation shaft of the compressor, and a supply source for supplying compressed air to the air motor.

  According to the above-described configuration, the air motor and the facility for operating the air motor can be made smaller than the motor and the facility for operating the motor. In addition, an air motor does not require auxiliary power like an electric motor.

  In the present invention, it is preferable that a supply path for supplying compressed gas from the supply source to the air motor is provided, and the supply path includes a pressure regulating valve.

  By adjusting the flow rate of the compressed gas supplied to the air motor by the pressure adjusting valve, the rotational speed of the air motor can be adjusted, and thus the auxiliary force of the exhaust gas turbine supercharger can be controlled. Immediately after the start of the internal combustion engine, the assist force for the exhaust gas turbine supercharger by the air motor is strengthened, and the assist force for the exhaust gas turbine supercharger by the air motor is weakened as the internal combustion engine operates normally. As a result, after a power failure occurs, stable power generation becomes possible.

  In the present invention, it is preferable that an air starter for starting the internal combustion engine is provided, and the supply source supplies the compressed gas to the air starter.

  By using the compressed gas included in the compressed gas supply source provided for operating the air motor for the operation of the air starter for starting the internal combustion engine, it is possible to prevent the power generation facility from being enlarged.

  In order to achieve the above object, the characteristic configuration of the power generation facility according to the present invention is that an auxiliary mechanism having any one of the above-described characteristic configurations is provided.

  In the power generation facility, the exhaust gas turbocharger can be assisted immediately after the internal combustion engine is started.

  In the present invention, it is preferable to operate when a power failure occurs.

  By providing this power generation facility in the facility, the facility can be operated even if a power failure occurs.

  In order to achieve the above object, the characteristic configuration of the control method according to the present invention is a control method for an auxiliary mechanism having any one of the above-described characteristic configurations. The adjustment valve is opened to rotate the air motor. When the air motor reaches a steady rotation speed, a power load is applied. When a predetermined time elapses, the pressure adjustment valve is gradually closed to stop the air motor.

  According to the above-described configuration, it is possible to supply stable power at an early stage after a power failure occurs.

It is principal part explanatory drawing of the power generation equipment provided with the auxiliary mechanism. It is explanatory drawing explaining assistance of rotation of the exhaust gas turbine supercharger by an auxiliary mechanism.

  Hereinafter, embodiments of an auxiliary mechanism according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a main part of power generation equipment provided in a facility such as an office building, a factory, or a hospital. The power generation facility is a facility for sustaining the operation of the facility even if a power failure occurs, and includes an emergency generator (not shown) and an internal combustion engine 1 for operating the generator. .

  The generator is a machine that converts mechanical energy output from the output shaft of the internal combustion engine 1 into electrical energy, and is provided for supplying electricity to a facility and maintaining its operation when a power failure occurs. It has been. In addition, since the specific structure of a generator is well-known, description is abbreviate | omitted.

  The internal combustion engine 1 is an engine that converts thermal energy into mechanical energy, and is a gas engine in the present embodiment. The internal combustion engine 1 may be a diesel engine.

  The internal combustion engine 1 combusts an air-fuel mixture in which fuel gas and air are mixed in a cylinder, reciprocates a piston in the cylinder by pressure generated at that time, converts this into rotational motion by a crank, and outputs an output shaft. Is configured to output from.

  The power generation facility further includes an air starter 2 for starting the internal combustion engine 1 and a compressed gas tank 3 as a supply source for supplying compressed gas to the air starter 2. The compressed gas is a gas having a pressure capable of operating the air starter 2 and the air motor 11 described later, and examples of the gas include air and an inert gas such as nitrogen.

  The air starter 2 is a device for rotating a crank in a stopped state when the internal combustion engine 1 is started, and includes an air motor or the like that is operated by compressed gas supplied from the compressed gas tank 3.

  An exhaust gas turbine supercharger 4 is provided in a supply / exhaust pipe of the internal combustion engine 1.

  The exhaust gas turbine supercharger 4 connects the turbine 5 that is rotated by the energy of the exhaust gas of the internal combustion engine 1, the compressor 6 that compresses the supply gas using the rotation of the turbine 5, and the turbine 5 and the compressor 6. A shaft 7 is provided.

  An air supply pipe 8 extending from the compressor 6 to the internal combustion engine 1 is provided with an intercooler 9 and a throttle valve 10.

  An output shaft 12 of an air motor 11 is connected to the shaft 7. The air motor 11 is a device that operates using the compressed gas in the compressed gas tank 3 as a power source, and the rotation of the turbine 5 and the compressor 6 of the exhaust gas turbine supercharger 4 is assisted by the rotation of the air motor 11.

  A pressure adjusting valve 14 is provided in the supply path 13 for supplying the compressed gas from the compressed gas tank 3 to the air motor 11. The rotational speed of the air motor 11 can be adjusted by adjusting the flow rate of the compressed gas supplied to the air motor 11 by the pressure adjustment valve 14. Therefore, the auxiliary force of the exhaust gas turbine supercharger 4 by the air motor 11 can be controlled.

  In addition, you may provide the rotation speed measurement mechanism which measures the rotation speed of the internal combustion engine 1, and the interlocking mechanism which links this and the pressure regulation valve 14. FIG. The interlock mechanism increases the opening of the pressure regulating valve 14 when the rotational speed of the internal combustion engine 1 measured by the rotational speed measurement mechanism falls below the target rotational speed, and the pressure when the rotational speed of the internal combustion engine 1 exceeds the target rotational speed. The opening degree of the regulating valve 14 is decreased.

  Immediately after the internal combustion engine 1 is started, the auxiliary force for the exhaust gas turbine supercharger 4 by the air motor 11 is strengthened, and the auxiliary force for the exhaust gas turbine supercharger 4 by the air motor 11 is weakened as the internal combustion engine 1 operates in a steady state. The operation state from immediately after the start of the internal combustion engine 1 to the steady operation can be stabilized. As a result, after a power failure occurs, stable power generation can be achieved early.

  The air motor 11 and the compressed gas tank 3 can be reduced in size as compared with the conventional configuration including an electric motor for assisting the rotation of the exhaust gas turbine supercharger 4 and equipment for operating the electric motor. In addition, the air motor 11 does not require auxiliary power like an electric motor.

  In the present embodiment, the power generation facility generates power by using the compressed gas included in the compressed gas tank 3 of the compressed gas provided for operating the air motor 11 to rotate the air starter 2 for starting the internal combustion engine 1. An increase in the size of the entire facility can be prevented.

  Next, a method for controlling the air motor 11 included in the power generation facility configured as described above will be described.

  As shown in FIG. 2, when a power failure occurs in the facility, the power generation facility supplies compressed gas from the compressed gas tank 3 to the air starter 2, rotates the air starter 2, opens the throttle valve 10, and mixes the internal combustion engine 1 with air-fuel mixture. And the internal combustion engine 1 is started by igniting with a spark plug. Note that the opening degree of the throttle valve 10 when the internal combustion engine 1 is started is 100%.

  As the internal combustion engine 1 is started, the pressure adjustment valve 14 is gradually opened to start the air motor 11. As the air motor 11 is started, air is excessively supplied to the internal combustion engine 1 in a no-load state, so that the opening of the throttle valve 10 is reduced to avoid this.

  The turbine 5 and the compressor 6 of the exhaust gas turbine supercharger 4 are rotated by the operating force from the air motor 11 together with the exhaust gas from the internal combustion engine 1.

  The air motor 11 is brought to a steady rotational speed by the control of the pressure regulating valve 14, so that the rotational speeds of the turbine 5 and the compressor 6 are brought to a steady rotational speed, and the internal combustion engine 1 is brought to a steady operation accordingly.

  Then, since the generator can generate power, an electric load is applied. Since the rotational speed of the internal combustion engine 1 instantaneously decreases due to the input of electric power load, the throttle valve 10 is opened again to about 100%. The throttle valve 10 is controlled so as to be opened in such a manner that the opening degree is gradually increased, for example, over a predetermined time immediately after the power load is applied. Thereby, the rotation speed of the internal combustion engine 1 returns to the steady rotation speed. After the elapse of a predetermined time until the return, the throttle valve 10 and the pressure regulating valve 14 begin to close gradually, and after the air motor 11 is stopped, the throttle valve 10 finally has an opening degree of about 30%. Maintained. The throttle valve 10 and the pressure regulating valve 14 are controlled so as to be closed in such a manner that the opening degree is gradually decreased over a predetermined time after the power load is applied.

  As described above, after a power failure occurs, stable power supply can be achieved early by the power generation facility.

  In the above-described embodiment, the case where the exhaust gas turbine supercharger 4 has one stage has been described. However, the exhaust gas turbine supercharger 4 having the same configuration may be provided in two stages in series. In this case, each of the two-stage exhaust gas turbine superchargers 4 is provided with an air motor 11 that is operated by compressed gas that is branched and supplied from a common compressed gas tank 3.

  In the embodiment described above, the configuration in which the air starter 2 is used to start the internal combustion engine 1 has been described, but a cell motor may be used instead of the air starter 2. In this case, the power generation facility is separately provided with a storage battery or the like for operating the cell motor.

  The above-described embodiments are merely examples of the present invention, and the present invention is not limited by the description. The specific configuration of each part is appropriately changed and designed within the range where the effects of the present invention are exhibited. Is possible.

  The auxiliary mechanism according to the present invention can be preferably used for power generation equipment provided in facilities such as office buildings, factories, hospitals, and other facilities where operation of the facilities is stopped due to a power failure.

1: Internal combustion engine 2: Air starter 3: Compressed gas tank (supply source)
4: Exhaust gas turbine supercharger 5: Turbine 6: Compressor 11: Air motor 13: Supply path 14: Pressure adjusting valve

Claims (6)

In a power generation facility including an internal combustion engine and a generator, an auxiliary mechanism that assists in rotation of an exhaust gas turbine supercharger that supplies compressed gas to the internal combustion engine,
An air motor connected to a rotating shaft of a turbine and a compressor of the exhaust gas turbine supercharger;
An auxiliary mechanism comprising a supply source for supplying compressed gas to the air motor. A supply path for supplying compressed gas from the supply source to the air motor;
The auxiliary mechanism according to claim 1, wherein the supply path includes a pressure regulating valve.   The auxiliary mechanism according to claim 1, further comprising an air starter for starting the internal combustion engine, wherein the supply source supplies compressed gas to the air starter.   A power generation facility comprising the auxiliary mechanism according to any one of claims 1 to 3.   The power generation facility according to claim 4, wherein the power generation facility operates when a power failure occurs. A method for controlling an auxiliary mechanism according to any one of claims 1 to 3,
When a power failure occurs and the internal combustion engine starts, the pressure adjustment valve is opened and the air motor is rotated.
When the air motor reaches a steady rotational speed, a power load is turned on,
A control method comprising: gradually closing the pressure regulating valve and stopping the air motor when a predetermined time has elapsed.

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