JP4681465B2 - Exhaust turbocharger - Google Patents

Description

  The present invention is mainly applied to an exhaust turbocharger used for diesel engines and gas engines, and shifts between a rotating shaft of a turbine driven by the exhaust gas of the engine and a rotating shaft of a compressor that pumps supply air to the engine. An exhaust turbocharger configured to connect a generator to an exhaust turbocharger with an intervening machine and a turbine driven by exhaust gas of the engine and to drive a compressor that pumps supply air to the engine by an electric motor. Regarding the feeder.

  In a diesel engine or a gas engine equipped with an exhaust turbocharger, conventionally, when adjusting the supply air pressure in order to secure the required air supply amount, the turbine nozzle flow by the variable nozzle mechanism of the exhaust turbocharger has been conventionally used. Adjustment of the road area, adjustment of the opening of the exhaust bypass valve provided in the exhaust bypass passage of the turbocharger, adjustment of the opening of the throttle valve provided in the wake of the supercharger, and supply air branched from the supply passage It was by adjusting the opening degree of the air supply discharge valve provided in the discharge passage.

In Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-242687), a speed change mechanism including a planetary gear device is built in a compressor of a supercharger, and the ring gear of the planetary gear device is switched by attaching / detaching a friction plate. The rotational speed of the rotor of the compressor can be changed at a gear ratio determined by the gear ratio of the gears in the planetary gear device.
Patent Document 2 (Japanese Patent Laid-Open No. 2005-127261) discloses an electric motor that drives a compressor connected to a turbine that is driven by the exhaust gas of the engine and that compresses supply air to the engine. An internal combustion engine with an EGR system (exhaust gas recirculation system) having an exhaust turbocharger configured to rotate and drive the compressor via the electric motor by the electric power of the generator is shown. .

JP 2002-242687 A JP 2005-127261 A

As means for adjusting the supply air pressure in order to secure the required air supply amount of the engine, it is provided in the adjustment means for the turbine nozzle passage area by the variable nozzle mechanism of the exhaust turbo supercharger, and the exhaust bypass passage of the supercharger. In the exhaust gas bypass valve opening adjusting means, it is possible to adjust the supply air pressure while avoiding surging of the exhaust turbocharger, but the response speed to engine operating condition changes is slow. It is difficult to cope with sudden load changes.
In addition, in the throttle valve opening adjusting means provided in the wake of the turbocharger, when there is a sudden load change of the engine, the throttle valve is momentarily closed and the air supply resistance increases. Therefore, surging of the exhaust turbocharger is likely to occur.
Further, in the opening adjusting means of the air supply release valve provided in the air supply discharge passage branched from the air supply passage, the supercharger efficiency is reduced by the air supply discharge and the air supply is discharged. It cannot be used for gas engines that are premixed before the feeder.

Further, in the means of Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-242687), since a speed change mechanism including a planetary gear device is built in the compressor of the supercharger, the gear teeth in the planetary gear device are included. The speed of the compressor can be changed only by a specific gear ratio determined by the number ratio, and the speed of the compressor cannot be changed steplessly.
The means of Patent Document 1 (Japanese Patent Laid-Open No. 2005-127261) is adapted to an internal combustion engine with an EGR system (exhaust gas recirculation system) and performs stepless control of the rotation speed of the compressor by an electric motor. It cannot be applied to an engine other than an internal combustion engine with an EGR system.

  In view of the problems of the prior art, the present invention makes it possible to control the air supply amount and the air supply pressure by continuously controlling the compressor rotation speed without the surging of the supercharger, thereby reducing the required air supply amount of the engine. An object of the present invention is to provide an exhaust turbocharger that can minimize exhaust energy for securing and improve the overall efficiency of an engine plant.

  The present invention achieves such an object, and a transmission is interposed between a rotating shaft of a turbine driven by exhaust gas of an engine and a rotating shaft of a compressor that pumps supply air to the engine, and the rotation of the turbine is achieved. In the exhaust turbocharger configured to shift the number with the transmission at a predetermined transmission ratio and transmit the transmission to the compressor, the transmission is configured with a continuously variable transmission capable of changing the transmission ratio continuously. In addition, an air supply amount deviation between the required air supply amount of the engine set by the engine output (engine load) and the engine speed of the engine and the actual air supply amount (actual air supply amount) of the engine is calculated. Then, the actual rotational speed (compressor actual rotational speed) of the compressor is corrected using the air supply amount deviation to calculate the target rotational speed of the compressor, and the target rotational speed of the compressor and the torque are calculated. A control device is provided that calculates the transmission ratio of the transmission based on the actual rotational speed of the bin (actual turbine rotational speed) and controls the operation of the transmission based on the transmission ratio (Claim 1). .

In this invention, specifically, the following configuration is preferable.
That is, an air supply pressure sensor that detects an air supply pressure of the engine and inputs it to the control device, an air supply temperature sensor that detects an air supply temperature of the engine and inputs it to the control device, and a rotation of the compressor A compressor rotation number detector that detects the number of rotations and inputs the compressor rotation number to the control device; and a turbine rotation number detector that detects the rotation number of the turbine and inputs the rotation number to the control device. The actual supply air amount is calculated based on the supply air pressure detection value from the pressure sensor and the supply air temperature detection value from the supply air temperature sensor, and an air supply amount deviation between the required air supply amount and the actual air supply amount The compressor rotation speed detection value from the compressor rotation speed detector is corrected using the air supply amount deviation to calculate the target rotation speed of the compressor, and the target rotation speed of the compressor and the turbine rotation speed are calculated. The turbine rotation speed detection value from the output unit is configured to calculate the speed ratio of the transmission (claim 2).

Further, in this invention, preferably, an exhaust gas heat recovery device that recovers exhaust gas heat is installed in an exhaust pipe through which the exhaust gas at the turbine outlet flows.
Preferably, the engine is a power generation engine that directly drives a generator.

According to this invention, in the exhaust turbocharger in which the transmission is interposed between the rotating shaft of the turbine driven by the exhaust gas of the engine and the rotating shaft of the compressor that pumps the supply air to the engine, the transmission is The engine is composed of a continuously variable transmission whose speed ratio can be changed continuously, and the required air supply amount, the supply air pressure detection value, and the supply air temperature detection set by the engine output (engine load) and the engine speed. (Claim 2) An air supply amount deviation from the actual air supply amount obtained based on the value is calculated, a compressor rotational speed deviation corresponding to the air supply amount deviation is calculated, and the compressor rotational speed is calculated using the rotational speed deviation. The target rotation speed of the compressor is calculated by correcting the number detection value (actual rotation speed of the compressor), and the gear ratio of the transmission is calculated from the target rotation speed of the compressor and the detection value of the turbine rotation speed. Since the transmission is controlled by the gear ratio, the engine air supply and pressure are controlled by continuously controlling the compressor speed while maintaining the exhaust gas conditions on the turbine side at the required values. The air supply amount and the air supply pressure can be freely controlled while avoiding the surging of the supercharger.
In addition, the rotation speed of the compressor can be reduced while keeping the rotation speed on the turbine side constant, and the response speed of the engine plant is faster than that of an engine plant having a conventional exhaust bypass device, and the response of the engine plant can be improved. There is no pressure loss due to the exhaust bypass valve such as the exhaust bypass device.
In addition, when starting an engine with low exhaust energy on the turbine side or during low-load operation, the supply pressure can be increased by changing the gear ratio of the transmission and increasing the rotation speed of the compressor. Can be improved.

Furthermore, according to this invention, the required torque of the engine can be ensured by operating the compressor at the target rotational speed while minimizing the driving torque of the turbine, that is, the exhaust energy for driving the turbine.
Therefore, the amount of decrease in the exhaust temperature at the turbine for obtaining the required air supply amount can be reduced, and the exhaust temperature at the turbine outlet can be kept high, so that it is installed in the exhaust pipe at the turbine outlet. It is possible to increase the amount of heat recovered in the exhaust gas heat recovery device (Claim 5) and improve the overall efficiency of the engine plant equipped with the exhaust gas heat recovery device.

  According to the present invention, a generator is connected to a turbine driven by exhaust gas of the engine, and an electric motor that drives the compressor is connected to a compressor that pumps supply air to the engine. In the exhaust turbocharger configured to rotationally drive the compressor via a motor, the electric motor is configured by a variable speed electric motor, and is set by the engine output (engine load) of the engine and the engine speed. The air supply amount deviation between the required air supply amount of the engine and the actual air supply amount (actual air supply amount) of the engine is calculated, and the actual rotational speed (compressor of the compressor) is calculated using the air supply amount deviation. The target rotational speed of the compressor is calculated by correcting the actual rotational speed), and the rotational speed of the electric motor is calculated as the target rotational speed of the compressor. Characterized in that includes a controller that controls the operation in (claim 3).

In this invention, specifically, the following configuration is preferable.
That is, an air supply pressure sensor that detects an air supply pressure of the engine and inputs it to the control device, an air supply temperature sensor that detects an air supply temperature of the engine and inputs it to the control device, and a rotation of the compressor A compressor rotation speed detector that detects the number and inputs it to the control device, the control device comprising: a supply air pressure detection value from the supply air pressure sensor and a supply air temperature detection value from the supply air temperature sensor The actual air supply amount is calculated on the basis of the air supply amount, the air supply amount deviation between the required air supply amount and the actual air supply amount is calculated, and the compressor rotation speed from the compressor rotation speed detector is calculated using the air supply amount deviation. A target rotational speed of the compressor is calculated by correcting the number detection value.

Further, in this invention, preferably, an exhaust gas heat recovery device that recovers exhaust gas heat is installed in an exhaust pipe through which the exhaust gas at the turbine outlet flows.
Preferably, the engine is a power generation engine that directly drives a generator.

According to this invention, in the exhaust turbocharger configured to connect the generator to the turbine driven by the exhaust gas of the engine and to drive the compressor that pumps the supply air to the engine by the electric motor, The motor is composed of a variable speed electric motor, and is obtained based on the required engine air supply amount set by the engine output (engine load) and the engine speed, the supply air pressure detection value, and the supply air temperature detection value. Item 4) An air supply amount deviation from the actual air supply amount is calculated, a compressor rotational speed deviation corresponding to the air supply amount deviation is calculated, and a compressor rotational speed detection value (actual compressor actual value) is calculated using the rotational speed deviation. The target rotational speed of the compressor is calculated, and the operation speed of the electric motor is controlled steplessly to the target rotational speed of the compressor. Because,
By driving the compressor with a variable-speed electric motor, the engine speed is increased by increasing the rotational speed of the electric motor when starting an engine with low exhaust energy on the turbine side or during low-load operation. The air pressure can be increased, thereby improving the startability of the engine.
In addition, while maintaining the exhaust gas condition on the turbine side at the required value, the engine air supply pressure can be controlled by changing the rotation speed of the variable speed electric motor and controlling the rotation speed of the compressor. The supply pressure can be freely controlled while avoiding surging.
In addition, since the rotation speed of the electric motor can be reduced and the rotation speed of the compressor can be reduced while the rotation speed on the turbine side is kept constant, the response speed is faster than that of an engine plant having a conventional exhaust bypass device. It is fast and can improve the responsiveness of the engine plant, and there is no pressure loss due to an exhaust bypass valve such as an exhaust bypass device.
Even when the back pressure on the turbine side increases, the required air supply can be maintained by maintaining the compressor speed at the required speed with an electric motor, preventing abnormal combustion due to insufficient air supply. it can.

Further, according to this invention, the required torque of the engine is obtained by operating the compressor at the target rotational speed by the electric motor composed of the variable speed electric motor while minimizing the turbine driving torque, that is, the exhaust energy for driving the turbine. The amount can be secured.
Therefore, the amount of decrease in the exhaust temperature at the turbine for obtaining the required air supply amount can be reduced, and the exhaust temperature at the turbine outlet can be kept high, so that it is installed in the exhaust pipe at the turbine outlet. It is possible to increase the amount of heat recovered in the exhaust gas heat recovery device (Claim 5) and improve the overall efficiency of the engine plant equipped with the exhaust gas heat recovery device.
Further, in an engine plant in which a generator is driven by an engine (Claim 6), since the required engine air supply amount can be secured with a small amount of exhaust energy as described above, surplus exhaust energy of the turbine is recovered as power of the generator. Even if the exhaust gas heat recovery device is not provided, the overall efficiency of the engine plant can be improved.

According to the present invention, in an exhaust turbocharger in which a transmission is interposed between a rotary shaft of an exhaust gas turbine and a rotary shaft of a compressor that pumps supply air, the transmission is configured by a continuously variable transmission. At the same time, an air supply amount deviation between the required air supply amount and the actual air supply amount of the engine is calculated, and the actual engine speed is corrected using the air supply amount deviation to calculate the target engine speed of the compressor. , Control the operation of the transmission comprising the continuously variable transmission based on the gear ratio calculated from the target rotational speed and the turbine rotational speed detection value,
Alternatively, in an exhaust turbocharger configured to connect a generator to the exhaust gas turbine and to drive the compressor with an electric motor, the electric motor is configured with a variable speed electric motor and the engine is required. A variable speed electric motor calculates an air supply amount deviation between the air supply amount and the actual air supply amount, corrects the actual rotational speed of the compressor using the air supply amount deviation, calculates a target rotational speed of the compressor, and Because the operation control of the rotation speed of the electric motor consisting of the compressor to the target rotation speed of the compressor,
While maintaining the exhaust gas conditions on the turbine side at the required values, the air supply amount and the air supply pressure of the engine can be controlled by controlling the rotation speed of the compressor steplessly. The amount and supply pressure can be controlled freely.
In addition, the rotation speed of the compressor can be reduced while keeping the rotation speed on the turbine side constant, the response speed becomes faster, the response of the engine plant can be improved, and an exhaust bypass valve such as an exhaust bypass device No pressure loss due to.
In addition, when starting an engine with low exhaust energy on the turbine side or during low-load operation, change the gear ratio of the transmission, or change the rotation speed of the electric motor to increase the rotation speed of the compressor, thereby increasing the supply air pressure. As a result, the engine startability can be improved.

Furthermore, according to the present invention, the required air supply amount of the engine can be secured by operating the compressor at the target rotational speed while minimizing the driving torque of the turbine, that is, the exhaust energy for driving the turbine.
Therefore, the amount of decrease in the exhaust gas temperature at the turbine for obtaining the required supply air amount can be small, and the exhaust gas temperature at the turbine outlet can be kept high, thereby reducing the amount of exhaust gas heat recovered by the exhaust gas heat recovery device. The total efficiency of the engine plant equipped with the exhaust gas heat recovery device can be improved.
In addition, in an engine plant that drives a generator by an engine, the required supply amount of the engine can be secured with a small amount of exhaust energy as described above, so that surplus exhaust energy of the turbine can be recovered as power of the generator, and the exhaust gas Even when no heat recovery device is provided, the overall efficiency of the engine plant can be improved.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.
However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is an overall configuration diagram of a gas engine provided with an exhaust turbocharger according to a first embodiment of the present invention, and FIG. 2 is a control block diagram of the exhaust turbocharger in the first embodiment.
In FIG. 1, 1 is an engine (gas engine), and 2 is a generator that is directly connected to the engine 1. Reference numeral 20 denotes a supercharger (exhaust turbocharger), which is a turbine 8 driven by exhaust gas introduced from the engine 1 through an exhaust pipe 7, a compressor 5 that pumps supply air to the engine 1 through an air supply pipe 6, A transmission 9 is interposed between the rotating shaft of the turbine 8 and the rotating shaft of the compressor 5.
The transmission 9 is composed of various continuously variable transmissions including a fluid coupling whose speed ratio is continuously variable and can be changed continuously.

15 is an air pipe, 3 is a gas supply pipe, and 4 is a gas amount adjusting valve provided in the gas supply pipe 3 to adjust the flow rate of the fuel gas. The fuel gas whose flow rate is adjusted by the gas amount adjusting valve 4 and The air that has passed through the air pipe is mixed at a target air-fuel ratio and supplied to the intake port of the compressor 5 through the compressor inlet air supply pipe 17.
Reference numeral 16 denotes an exhaust pipe connected to the exhaust gas outlet of the turbine 8. Reference numeral 30 denotes an exhaust gas heat recovery apparatus. The exhaust gas heat recovery apparatus 30 recovers exhaust gas heat exhausted through the exhaust pipe 16 after driving the turbine 8. .

Reference numeral 100 denotes a control device that performs calculation and control, which will be described later. Reference numeral 13 denotes an engine rotation speed detector that detects the rotation speed of the engine 1. Reference numeral 12 denotes load detection that detects an output of the engine 1, that is, an engine load from the generator 2. The detected value of the engine speed from the engine speed detector 13 and the detected value of the engine load from the load detector 12 are input to the control device 100.
10 is a supply air pressure sensor that detects the supply air pressure of the engine 1 and inputs it to the control device 100; 11 is a supply air temperature sensor that detects the supply air temperature of the engine 1 and inputs it to the control device 100; Is a compressor rotational speed detector that detects the rotational speed of the compressor 5 and inputs it to the control apparatus 100, and 18 is a turbine rotational speed detector that detects the rotational speed of the turbine 8 and inputs it to the control apparatus 1. .
The control device 100 adjusts the opening degree of the gas amount adjusting valve 4 based on the detected value of the engine speed and the detected value of the engine load, and detects from the detectors and sensors. The following calculation and control are performed based on the signal.

That is, in the control block diagram of the exhaust turbocharger shown in FIG. 2, the detected value of the supply air pressure of the engine 1 from the supply air pressure sensor 10 and the supply air of the engine 1 from the supply air temperature sensor 11. The detected temperature value is input to the actual supply air amount calculation unit 101 of the control device 100.
The actual air supply amount, that is, the actual air supply amount of the engine 1 is proportional to the air supply pressure and the air supply temperature as shown in FIG. 5B, and the actual air supply amount calculation unit 101 uses the air supply pressure. The actual supply air amount Q1 is calculated using the detected value Ps, the detected value Ts of the supply air temperature, and the stroke volume Vh of the engine.
This actual air supply amount Q <b> 1 is input to the air supply amount deviation calculation unit 104.

Further, the detected value of the engine speed from the engine speed detector 13 and the detected value of the engine load from the load detector 12 are input to the required supply amount calculation unit 102 of the control device 100.
Reference numeral 103 denotes a required air supply amount setting unit, as shown in FIG. 5A, engine output, that is, engine load and engine speed, and required air supply amount (target air supply amount) corresponding to the engine load and engine speed. And the relationship is set.
The required air supply amount calculation unit 102 calculates (extracts) the required air supply amount Q0 corresponding to the detected value of the engine speed and the detected value of the engine load from the required air supply amount setting unit 103.
The required air supply amount Q0 is an air supply amount required for performing the required complete combustion during operation at the engine speed and engine load. The required air supply amount Q0 is the air supply amount deviation calculating unit 104. Is input.

In the air supply amount deviation calculation unit 104, an air supply amount deviation ΔQ (= | Q0−Q1 |) between the required air supply amount Q0 and the actual air supply amount Q1 is calculated. input.
In the compressor rotation speed deviation calculation unit 105, as shown in FIG. 5C, as the operation characteristics of the compressor 5, the relationship between the air supply amount (the supply air supply amount of the compressor 5) Q and the compressor rotation speed Nc is set. When the air supply amount deviation ΔQ is input, the compressor rotational speed deviation ΔNc corresponding to the air supply amount deviation ΔQ is calculated from the operating characteristics of FIG. input.

The compressor rotational speed calculation unit 106 corrects the rotational speed detection value Nc of the compressor 5 input from the compressor rotational speed detector 20 with the compressor rotational speed deviation ΔNc, and calculates the target rotational speed Nc0 of the compressor 5. To do.
That is, in the compressor rotation speed calculation unit 106, the actual rotation speed Nc of the compressor 5 and the compressor rotation speed deviation ΔNc corresponding to the supply air amount deviation ΔQ between the required air supply amount Q0 and the actual air supply amount Q1 are calculated. Is added and subtracted to calculate the target rotational speed Nc0 of the compressor 5 (Nc0 = Nc ± ΔNc).
In this case, when the actual air supply amount Q1 is smaller than the required air supply amount Q0 (air supply amount deviation ΔQ = Q0−Q1> 0), the compressor 5 rotates as the target rotational speed Nc0 = Nc + ΔNc. When the actual air supply amount Q1 is larger than the required air supply amount Q0 (supply amount deviation ΔQ = Q0−Q1 <0), the target rotational speed Nc0 = Nc of the compressor 5 is set. −ΔNc is made smaller than the rotation speed detection value Nc of the compressor 5.
The target rotational speed Nc0 of the compressor 5 calculated by the compressor rotational speed calculation unit 106 is input to the transmission ratio calculation unit 108.

The speed ratio calculation unit 108 receives the rotation speed detection value Nt of the turbine 8 from the turbine speed detector 18, and the speed ratio calculation section 108 receives the signal from the compressor speed calculation section 106. A gear ratio y = Nc0 / Nt as shown in FIG. 5D, which is a ratio between the target rotational speed Nc0 of the compressor 5 and the rotational speed detection value Nt of the turbine 8, is calculated. An input is made to the transmission 9 and the operation of the transmission 9 is controlled with a gear ratio y.
Therefore, the transmission 9 changes the speed of the compressor 5 so that the rotational speed of the compressor 5 becomes the target rotational speed Nc0 according to the change of the rotational speed detection value Nt of the turbine 8 even if the rotational speed detection value Nt of the turbine 8 changes. It is operated by changing the ratio y.

According to the first embodiment, an exhaust turbocharger having a transmission 9 interposed between a rotating shaft of a turbine 8 driven by exhaust gas of the engine 1 and a rotating shaft of a compressor 5 that pumps supply air to the engine 1. In the feeder 20, the transmission 9 is formed of a continuously variable transmission whose speed ratio can be changed continuously, and the required air supply amount Q0 of the engine 1 set by the engine output (engine load) and the engine speed. Then, an air supply amount deviation ΔQ (= | Q0−Q1 |) with the actual air supply amount Q1 obtained based on the air supply pressure detection value and the air supply temperature detection value is calculated, and this air supply amount deviation ΔQ is handled. The compressor rotational speed deviation ΔNc is calculated, the compressor rotational speed detection value (actual compressor rotational speed) Nc is corrected using the rotational speed deviation ΔNc, and the compressor target rotational speed Nc0 is calculated. Since the transmission gear ratio y of the transmission 9 is calculated from the target rotational speed Nc0 and the turbine rotational speed detection value Nt, and the transmission 9 is controlled by the transmission gear ratio y, the exhaust gas condition on the turbine 8 side is set to a required value. In the held state, the air supply amount and the air supply pressure of the engine 1 can be controlled by controlling the rotation speed of the compressor 5 in a stepless manner, and the air supply amount and the air supply pressure can be controlled while avoiding surging of the supercharger 20. It can be controlled freely.
In addition, the rotational speed Nc of the compressor 5 can be reduced while the rotational speed Nt on the turbine 8 side is kept constant, and the response speed of the engine plant is faster than that of an engine plant having a conventional exhaust bypass device. And the pressure loss due to the exhaust bypass valve such as the exhaust bypass device is eliminated.
In addition, when starting the engine 1 with low exhaust energy on the turbine 8 side or during low load operation, the supply pressure can be increased by changing the speed ratio y of the transmission 9 to increase the rotational speed Nc of the compressor 5, Thereby, the startability of the engine 1 can be improved.

Furthermore, according to the first embodiment, the driving torque of the turbine 8, that is, the exhaust energy for driving the turbine 8, is minimized, the compressor 5 is operated at the target rotational speed Nc0, and the required air supply amount Q0 of the engine 1 is reached. Can be secured.
Accordingly, the amount of decrease in the exhaust temperature at the turbine 8 for obtaining the required air supply amount Q0 can be reduced, so that the exhaust temperature at the outlet of the turbine 8 can be kept high, thereby the exhaust pipe 16 at the outlet of the turbine 8. It is possible to increase the amount of recovered exhaust gas heat in the exhaust gas heat recovery device 30 installed in the engine, and to improve the overall efficiency of the engine plant equipped with the exhaust gas heat recovery device 30.
Further, in the engine plant in which the generator 1 is driven by the engine 1 as in this embodiment, the required supply air amount Q0 of the engine 1 can be secured with a small amount of exhaust energy as described above. Can be recovered as the electric power of the generator 2, and the overall efficiency of the engine plant can be improved even when the exhaust gas heat recovery device 30 is not provided.

FIG. 3 is an overall configuration diagram of a gas engine having an exhaust turbocharger according to a second embodiment of the present invention, and FIG. 4 is a control block diagram of the exhaust turbocharger in the second embodiment.
In the second embodiment, the transmission 9 in the first embodiment is removed, the turbine generator 22 is connected to the turbine 8 driven by the exhaust gas of the engine 1, and the supply air is pumped to the engine 1. An electric motor 21 composed of a variable speed electric motor that drives the compressor 5 is connected to the compressor 5, and the turbine generator 22 and the electric motor 21 are electrically connected (29 is a connection line). The electric motor 21 is driven by the generated power.
Other configurations are the same as those of the first embodiment shown in FIG. 1, and the same members and elements are denoted by the same reference numerals (the air pipe 15, the gas supply pipe 3, and the gas amount adjusting valve 4 in FIG. 1). Is omitted).

Next, the operation of the control device 100 in the second embodiment, that is, the control operation of the exhaust turbocharger 20 will be described with reference to FIG.
In FIG. 4, the detected value of the supply air pressure of the engine 1 from the supply air pressure sensor 10 and the detected value of the supply air temperature of the engine 1 from the supply air temperature sensor 11 are the actual supply air of the control device 100. It is input to the quantity calculation unit 101. The actual air supply amount, that is, the actual air supply amount of the engine 1 is proportional to the air supply pressure and the air supply temperature as shown in FIG. 5B, and the actual air supply amount calculation unit 101 uses the air supply pressure. The actual supply air amount Q1 is calculated using the detected value Ps, the detected value Ts of the supply air temperature, and the stroke volume Vh of the engine. This actual air supply amount Q <b> 1 is input to the air supply amount deviation calculation unit 104.

Further, the detected value of the engine speed from the engine speed detector 13 and the detected value of the engine load from the load detector 12 are input to the required supply amount calculation unit 102 of the control device 100.
Reference numeral 103 denotes a required air supply amount setting unit, as shown in FIG. 5A, engine output, that is, engine load and engine speed, and required air supply amount (target air supply amount) corresponding to the engine load and engine speed. And the relationship is set.
The required air supply amount calculation unit 102 calculates (extracts) the required air supply amount Q0 corresponding to the detected value of the engine speed and the detected value of the engine load from the required air supply amount setting unit 103. The required air supply amount Q0 is an air supply amount required for performing the required complete combustion during operation at the engine speed and engine load. The required air supply amount Q0 is the air supply amount deviation calculating unit 104. Is input.

  In the air supply amount deviation calculation unit 104, an air supply amount deviation ΔQ (= | Q0−Q1 |) between the required air supply amount Q0 and the actual air supply amount Q1 is calculated. input. In the compressor rotation speed deviation calculation unit 105, as shown in FIG. 5C, the relationship between the supply air amount (the supply air supply amount of the compressor 5) Q and the compressor rotation speed Nc is set as the operation characteristics of the compressor 5. When the air supply amount deviation ΔQ is input, the compressor rotational speed deviation ΔNc corresponding to the air supply amount deviation ΔQ is calculated from the operating characteristics of FIG. To do.

The compressor rotational speed calculation unit 106 corrects the rotational speed detection value Nc of the compressor 5 input from the compressor rotational speed detector 20 with the compressor rotational speed deviation ΔNc, and calculates the target rotational speed Nc0 of the compressor 5. To do.
That is, in the compressor rotation speed calculation unit 106, the actual rotation speed Nc of the compressor 5 and the compressor rotation speed deviation ΔNc corresponding to the supply air amount deviation ΔQ between the required air supply amount Q0 and the actual air supply amount Q1 are calculated. Is added and subtracted to calculate the target rotational speed Nc0 of the compressor 5 (Nc0 = Nc ± ΔNc).
In this case, when the actual air supply amount Q1 is smaller than the required air supply amount Q0 (air supply amount deviation ΔQ = Q0−Q1> 0), the compressor 5 rotates as the target rotational speed Nc0 = Nc + ΔNc. When the actual air supply amount Q1 is larger than the required air supply amount Q0 (supply amount deviation ΔQ = Q0−Q1 <0), the target rotational speed Nc0 = Nc of the compressor 5 is set. −ΔNc is made smaller than the rotation speed detection value Nc of the compressor 5.
The above operation is the same as that of the first embodiment.

The target rotational speed Nc0 of the compressor 5 calculated by the compressor rotational speed calculation unit 106
Is input to the electric motor rotation speed setting unit 110.
The electric motor rotational speed setting unit 110 controls the current value of the electric motor 21 that directly drives the compressor 5 to operate the compressor 5 at the target rotational speed Nc0.
Therefore, even if the rotation speed detection value Nt of the turbine 8 changes, the electric motor 21 changes the rotation speed of the compressor 5 to the target rotation speed Nc0 according to the change of the rotation speed detection value Nt of the turbine 8. It is operated by changing the current value.

According to the second embodiment, the generator 2 is connected to the turbine 8 driven by the exhaust gas of the engine 1, and the compressor 5 that pumps the supply air to the engine 1 is driven by the variable speed electric motor 21. In the constructed exhaust turbocharger 20, the actual air supply amount Q 0 set by the engine output (engine load) and the engine speed, the actual supply air pressure detection value, and the actual supply air temperature detection value are obtained. An air supply amount deviation ΔQ with respect to the air supply amount Q1 is calculated, a rotation speed deviation ΔNc of the compressor 5 corresponding to the air supply amount deviation ΔQ is calculated, and a compressor speed detection value (compressor) is calculated using the rotation speed deviation ΔNc. 5), the target rotational speed Nc0 of the compressor 5 is calculated, and the rotational speed of the electric motor 21 is steplessly adjusted. Since the operation control to c0,
By driving the compressor 5 with the variable-speed electric motor 21, the engine 5 with a small exhaust energy is started and the electric motor 21 is rotated to increase the rotation speed of the engine 5 when starting the engine or operating at a low load. By increasing the speed, the supply air pressure can be increased, whereby the startability of the engine 1 can be improved.
Further, the supply pressure of the engine 1 can be controlled by changing the rotational speed of the variable speed electric motor 21 and controlling the rotational speed of the compressor 5 while maintaining the exhaust gas condition on the turbine 8 side at a required value. The air supply pressure can be freely controlled while avoiding surging of the supercharger 20.
Further, since the rotational speed of the variable speed electric motor 21 can be reduced and the rotational speed of the compressor 5 can be decelerated while the rotational speed on the turbine 8 side is kept constant, an engine having a conventional exhaust bypass device is provided. The response speed of the engine plant is faster than that of the plant, and the responsiveness of the engine plant can be improved, and pressure loss due to an exhaust bypass valve such as an exhaust bypass device is eliminated.
Further, even when the back pressure on the turbine 8 side increases, the required air supply amount can be maintained by maintaining the rotation speed of the compressor 5 at the required rotation speed by the variable speed electric motor 21. Abnormal combustion can be prevented.

Further, according to the second embodiment, the driving torque of the turbine 8, that is, the exhaust energy for driving the turbine 8 is minimized, and the compressor 5 is operated at the target rotational speed by the variable speed electric motor 21 to thereby drive the engine 1. The required air supply amount Q0 can be secured.
Accordingly, the amount of decrease in the exhaust temperature at the turbine 8 for obtaining the required air supply amount Q0 can be small, and the exhaust temperature at the outlet of the turbine 8 can be kept high. It is possible to increase the amount of heat recovered from the exhaust gas heat recovery device 30 installed, and the overall efficiency of the engine plant including the exhaust gas heat recovery device 30 can be improved.
Moreover, in the engine plant which drives the generator 2 with the engine 1, since the required air supply amount Q0 of the engine 1 can be secured with a small amount of exhaust energy as described above, the surplus exhaust energy of the turbine 8 is used as the power of the generator 2. Even if the exhaust gas heat recovery device 30 is not provided, the overall efficiency of the engine plant can be improved.

  According to the present invention, it is possible to control the supply air amount and the supply air pressure by continuously controlling the compressor rotation speed without surging of the supercharger, and the exhaust gas for ensuring the necessary supply air amount of the engine. An exhaust turbocharger capable of minimizing energy and improving the overall efficiency of the engine plant can be provided.

1 is an overall configuration diagram of a gas engine provided with an exhaust turbocharger according to a first embodiment of the present invention. It is a control block diagram of the exhaust turbocharger in the first embodiment. It is a whole block diagram of the gas engine provided with the exhaust gas turbocharger which concerns on 2nd Example of this invention. It is a control block diagram of the exhaust gas turbocharger in the second embodiment. (A), (B), (C), (D) is a relationship diagram between engine performance and supercharger performance in the first and second embodiments.

Explanation of symbols

1 Engine (gas engine)
2 Generator 3 Gas supply pipe 4 Gas amount adjusting valve 5 Compressor 6 Air supply pipe 7 Exhaust pipe 8 Turbine 9 Transmission 10 Supply air pressure sensor 11 Supply air temperature sensor 12 Load detector 13 Engine speed detector 15 Air pipe 16 Exhaust Pipe 17 Compressor inlet air supply pipe 18 Turbine rotational speed detector 19 Compressor rotational speed detector 20 Supercharger (exhaust turbocharger)
21 Electric motor 22 Turbine generator 30 Exhaust gas heat recovery device 100 Control device

Claims (6)

  A transmission is interposed between a rotating shaft of a turbine driven by exhaust gas of the engine and a rotating shaft of a compressor that pumps supply air to the engine, and the rotational speed of the turbine is adjusted at a predetermined gear ratio by the transmission. In the exhaust turbocharger configured to shift and transmit to the compressor, the transmission is configured with a continuously variable transmission whose speed ratio can be changed continuously, and the engine load and engine rotation of the engine Calculating an air supply amount deviation between the required air supply amount of the engine set by the number and the actual air supply amount of the engine, and correcting the actual rotational speed of the compressor using the air supply amount deviation The target rotational speed of the compressor is calculated, the transmission gear ratio of the transmission is calculated from the target rotational speed of the compressor and the actual rotational speed of the turbine, and the transmission is operated by the transmission gear ratio. Exhaust turbo supercharger, characterized in that it includes a Gosuru controller.   An air supply pressure sensor that detects the supply air pressure of the engine and inputs it to the control device, an air supply temperature sensor that detects the supply air temperature of the engine and inputs it to the control device, and a rotation speed of the compressor A compressor rotation speed detector that detects and inputs the compressor rotation speed to the control device; and a turbine rotation speed detector that detects the rotation speed of the turbine and inputs the turbine rotation speed to the control device. The actual supply air amount is calculated on the basis of the detected supply air pressure value from the intake air temperature and the detected supply air temperature value from the supply air temperature sensor, and the supply air amount deviation between the required supply air amount and the actual supply air amount is calculated. The compressor rotational speed detection value from the compressor rotational speed detector is corrected using the air supply amount deviation to calculate the target rotational speed of the compressor, and the target rotational speed of the compressor and the turbine rotational speed detector Exhaust turbo supercharger according to claim 1, characterized in that it is configured to calculate the transmission ratio of the transmission by the turbine speed detected value of et.   A generator is connected to a turbine driven by exhaust gas of the engine, and an electric motor that drives the compressor is connected to a compressor that pumps supply air to the engine, and the electric power of the generator is connected to the turbine via the electric motor. In the exhaust turbocharger configured to rotationally drive the compressor, the electric motor is configured by a variable speed electric motor, and the required air supply amount of the engine set by the engine load and the engine speed of the engine Calculating an air supply amount deviation from an actual air supply amount of the engine, correcting an actual rotational speed of the compressor using the air supply amount deviation, calculating a target rotational speed of the compressor, and the electric motor. Exhaust turbocharger characterized by comprising a control device for controlling the operation of the compressor to the target rotational speed of the compressor   An air supply pressure sensor that detects the supply air pressure of the engine and inputs it to the control device, an air supply temperature sensor that detects the supply air temperature of the engine and inputs it to the control device, and a rotation speed of the compressor A compressor rotation speed detector that detects and inputs to the control device, the control device based on a supply air pressure detection value from the supply air pressure sensor and a supply air temperature detection value from the supply air temperature sensor; Calculating the actual air supply amount, calculating an air supply amount deviation between the required air supply amount and the actual air supply amount, and detecting the compressor speed from the compressor speed detector using the air supply amount deviation The exhaust turbocharger according to claim 3, wherein the exhaust turbocharger is configured to calculate a target rotational speed of the compressor by correcting the value.   The exhaust gas turbocharger according to any one of claims 1 to 4, wherein an exhaust gas heat recovery device that recovers exhaust gas heat is installed in an exhaust pipe through which exhaust gas at the turbine outlet flows. The exhaust turbocharger according to any one of claims 1 to 4, wherein the engine is a power generation engine that directly drives a generator.

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