JP6202948B2 - Turbocharged engine and method for loading the same - Google Patents

Description

The present invention comprises an engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber,
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
The present invention relates to a turbocharged engine having a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed, and a method for loading the same.

An engine-driven generator that is rotationally driven by the rotational power generated by the engine body is required to follow the load suddenly. In particular, in the case of an emergency generator, it is required that a load as large as possible can be quickly applied from an unloaded state immediately after the engine body is started (initial load application). If the initial load application rate, which is the ratio of the initial input load to the rated output of the engine body, is high, it is possible to supply power quickly and stably to an important load that needs to be supplied with priority even if a power failure occurs.
On the other hand, in a turbocharged engine equipped with a turbocharger composed of a turbine that is rotated by exhaust energy of exhaust gas and a compressor that is connected to the turbine and driven to rotate, the speed of the engine body is controlled when the load increases rapidly. In addition to device delay, the turbocharger response delay prevents the necessary fresh air from being supplied to the engine body quickly, resulting in a decrease in output shaft rotation speed and stall (engine stop). .
In response to such problems, compressed nitrogen is introduced before the turbine when the initial load is applied in order to increase the rotation of the turbocharger when the initial load is applied, that is, to increase the amount of injected fuel due to the increase in intake pressure (Patent Document) 1), supplying compressed air from an air replenishment source to the engine body temporarily when the initial load is applied (see Patent Document 2), and applying a small load before applying a large load when the initial load is applied A switch (see Patent Document 3) that switches the load application state is proposed.

Japanese Patent No. 4580092 Japanese Patent No. 3608775 Japanese Patent No. 3592555

However, each of the techniques disclosed in Patent Documents 1 to 3 has the following problems. In the technique disclosed in Patent Document 1, it is necessary to always provide compressed nitrogen, which increases the cost and makes the configuration complicated.
In the technique disclosed in Patent Document 2, when the emergency generator combined with the emergency generator is rotationally driven by the rotational power generated by the engine body, a part of the intake pressure can be accumulated during operation. When the engine main body rotationally drives the emergency generator, as in the technique disclosed in Patent Document 1, it is necessary to always provide compressed air, resulting in high costs and a complicated configuration.
In the technique disclosed in Patent Document 3, it is necessary to switch the load application state, and it is necessary to prepare a load suitable for the load switching.

  The present invention has been made in view of the above-described problems, and the object thereof is to maintain a relatively simple configuration, while the responsiveness of the turbocharger with respect to initial load application is high, and the engine body falls into a stall. An object of the present invention is to provide a turbocharged engine capable of preventing this and a method for loading the same.

To achieve this object, a turbocharged engine according to the present invention is
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The first characteristic configuration is
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Bypass control for performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, and performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body With means ,
The bypass control means executes a correction process for correcting the opening degree of the bypass valve to the reduction side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. This is in that correction means is provided .
In order to achieve the above object, a turbocharged engine according to the present invention comprises:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The second feature configuration is
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Bypass control for performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, and performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body With means,
The bypass control means sets the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to a fuel rich side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. The correction means which performs the correction process which correct | amends to this is provided .

Further, a method for loading a turbocharged engine according to the present invention for achieving this object is as follows:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The first characteristic configuration is
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body ,
When the output of the engine body is insufficient after the initial load is applied and before the bypass closing process is performed, a correction process for correcting the opening degree of the bypass valve to the reduction side is executed .
Furthermore, a method for loading a turbocharged engine according to the present invention to achieve this object is as follows:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The second feature configuration is
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body,
A correction process for correcting the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to the fuel rich side when an output shortage of the engine body occurs after the initial load is applied and before the bypass block process is performed. The point is to execute.

According to the first characteristic configuration of the turbocharged engine and its load application method, in the engine body of the turbocharged engine, a bypass path that connects the outlet side and the inlet side of the compressor in the intake path is provided, A bypass valve is disposed in the bypass path. Then, in a state where the rotational speed of the engine main body is maintained at the target rotational speed by the rotational speed maintaining means, the bypass opening process is executed and the bypass valve is maintained open when the initial load is applied to the engine main body. Therefore, the flow of fresh air in the bypass passage is allowed, so that the pressure difference between the outlet side pressure and the outlet side pressure of the compressor is reduced, and the rotational load of the compressor is reduced. The rotation speed is increased. And since the responsiveness of a supercharger is higher when the rotational speed of the supercharger is higher, an initial load is applied to the engine body in this state, and the engine body with respect to the load is generated. The response of the engine output, which is the work of the rotational power, can be improved.
Further, after the initial load is applied, the bypass valve opened by the bypass opening process is closed by executing the bypass closing process. Then, since the flow of fresh air in the bypass passage is prohibited, the pressure difference between the outlet side pressure and the outlet side pressure of the compressor becomes large, and the compressor compresses fresh air sufficiently. As a result, engine efficiency can be improved and a more stable operation state can be maintained.
Furthermore, according to the first characteristic configuration of the turbocharged engine, after the initial load is applied and before the bypass closing process is performed, for example, in a situation where the opening of the throttle valve is fully open and cannot be further expanded, Even if an output shortage occurs, by executing the above correction process, the engine body output shortage can be resolved without relying on the expansion of the throttle valve opening, and the engine speed can be maintained at the target speed. can do.
In other words, in the above correction process, if the opening degree of the bypass valve is corrected to the reduction side, the rotational load of the compressor can be increased and the supercharging pressure for fresh air can be increased, resulting in a moderate increase in engine output. Can be made.
Furthermore, according to the second characteristic configuration of the turbocharged engine, after the initial load is applied and before the bypass closing process is performed, for example, in a situation where the opening of the throttle valve is fully open and cannot be further expanded, Even if an output shortage occurs, by executing the above correction process, the engine body output shortage can be resolved without relying on the expansion of the throttle valve opening, and the engine speed can be maintained at the target speed. can do.
That is, in the above correction process, if the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber is corrected to the fuel rich side, the amount of fuel input to the combustion chamber per cycle can be increased, and as a result, the engine output is reduced. It can be increased moderately.
In the above characteristic configuration, the engine body output shortage can be determined by monitoring the deviation of the engine body rotational speed with respect to the target rotational speed, the engine output deviation with respect to the target output, or the like.
Further, by appropriately combining the first and second characteristic configurations, in the correction process, the correction of the opening degree of the bypass valve to the reduction side and the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to the fuel rich side are performed. If both the correction and the correction are performed, the shortage of the output of the engine body can be resolved early and reliably.
Therefore, according to the present invention, while maintaining a relatively simple configuration, the turbocharger engine capable of preventing the engine main body from being stalled with high responsiveness of the supercharger with respect to the initial load application and its load application method Can be provided.

In addition to the first or second characteristic configuration of the turbocharged engine, the third characteristic configuration of the turbocharged engine according to the present invention is:
A throttle valve is disposed downstream of the compressor in the intake passage,
As the initial load is applied to the engine body, the rotation speed maintaining means executes the engine rotation speed maintaining control, whereby the opening degree of the throttle valve is increased.

According to the third characteristic configuration of the turbocharged engine, as the initial load is applied to the engine body, the rotation speed maintaining means executes the maintenance control for increasing the engine output and maintaining the engine rotation speed. In doing so, the degree of opening of a throttle valve provided on the downstream side of the compressor is rapidly increased to rapidly increase the flow rate of fuel and air-fuel mixture introduced to the engine, or the fuel supply amount is rapidly increased. Further, as in the latter case, when the fuel supply amount is suddenly increased, a throttle valve is used to increase the air supply amount in order to maintain the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber at a desired air-fuel ratio. The opening of the is rapidly expanded.
On the other hand, when the bypass opening process is executed and the rotation speed of the compressor is increased, fresh air is discharged from the outlet side of the compressor toward the downstream side thereof at a relatively high speed.
Therefore, in this state, when an initial load is applied to the engine body and the opening of the throttle valve arranged on the downstream side of the compressor is increased, a new high-pressure discharge is immediately after the expansion of the throttle valve. Since the gas is filled into the combustion chamber with its strong inertia, the engine output response can be further improved.

In addition to any of the first to third characteristic configurations described above, the fourth characteristic configuration of the turbocharged engine according to the present invention includes:
In the bypass closing process, the bypass control means gradually reduces the opening of the bypass valve as the engine output increases.

According to the fourth characteristic configuration of the turbocharged engine, in the bypass closing process after the initial load is applied, the opening degree of the bypass valve is gradually reduced as the engine output increases, thereby blocking the bypass valve. As the rotational load of the compressor increases, the exhaust energy of the exhaust gas supplied to the turbine increases as the engine output increases. Therefore, even after the initial load is applied, the rotation speed of the supercharger can be maintained at a high level, and a decrease in engine efficiency and a stall due to a sudden closing of the bypass valve can be avoided.

In addition to the second characteristic configuration of the turbocharged engine, the fifth characteristic configuration of the turbocharged engine according to the present invention is:
The bypass control means executes a correction process for correcting the opening degree of the bypass valve to the reduction side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. It is in the point provided with the correction means to do.

According to the fifth characteristic configuration of the turbocharged engine, after the initial load is applied and before the bypass closing process is executed, the output of the engine main body, for example, in a situation where the opening of the throttle valve cannot be further expanded in the fully opened state. Even if an insufficiency occurs, by executing the above correction process, the engine body output shortage can be resolved without relying on the expansion of the throttle valve opening, and the engine body rotational speed can be maintained at the target rotational speed. Can do.
In other words, in the above correction process, if the opening degree of the bypass valve is corrected to the reduction side, the rotational load of the compressor can be increased and the supercharging pressure for fresh air can be increased, resulting in a moderate increase in engine output. Can be made.

Schematic configuration diagram of turbocharged engine Explanatory drawing which shows the processing flow in the reference form of the load injection method of a turbocharged engine Explanatory drawing which shows the state transition in the reference form of the load injection method of a turbocharged engine Explanatory view showing a processing flow in the implementation form of load application method turbocharged engine Explanatory view showing a processing flow of a correction process executed by the load application method implementation form Explanatory view showing a state transition in the implementation form of load application method turbocharged engine

Embodiments of the present invention will be described with reference to the drawings.
A turbocharged engine 100 shown in FIG. 1 rotates an output shaft 50 by compressing and burning an air-fuel mixture M of a fuel gas F (an example of fuel) such as natural gas and air A in a combustion chamber 26a. The exhaust gas E discharged from the combustion chamber 26a is supplied to the engine body 26 that generates rotational power in the form and the turbine 32 provided in the exhaust path 27 of the engine body 26, and is connected to the turbine 32 in the intake path 20 And a supercharger 30 that compresses the air-fuel mixture M as fresh air that is taken into the combustion chamber 26a by a compressor 31 that is provided. Further, a detection result of a sensor or the like is input, and a control valve is based on the input signal. An engine control unit (hereinafter referred to as an ECU) 40 comprising a computer that controls the operation of the engine 100 is controlled. To have.

  Although this type of engine 100 is not shown in detail, the mixture M taken as fresh air from the intake passage 20 into the combustion chamber 26a is spark-ignited by a spark plug in a state compressed by the rise of the piston. By combustion and expansion, the piston is pushed down to output rotational power from the output shaft 50, and the exhaust gas E generated by the combustion is pushed out from the combustion chamber 26a to the exhaust passage 27 and discharged to the outside.

In the intake passage 20, an air cleaner 21 that purifies the air A, a Venturi mixer 14 that mixes the fuel gas F with the air A at an appropriate ratio, and a compressor 31 that compresses the air-fuel mixture M mixed in the mixer 14, A throttle valve 24 capable of adjusting the intake amount of the air-fuel mixture M into the combustion chamber 26a by adjusting the opening degree, and an intercooler 25 for cooling the air-fuel mixture M are provided in the order of description from the upstream side.
That is, in the intake passage 20, the air-fuel mixture M generated by mixing the fuel gas F and air A in the mixer 14 is compressed by the compressor 31 and then adjusted to a predetermined flow rate via the throttle valve 24. It is cooled by the intercooler 25 and introduced into the combustion chamber 26 a of the engine body 26.

  In the fuel supply path 11 that guides the fuel gas F to the mixer 14, a differential pressure regulator that keeps the difference between the pressure of the combustion air in the intake path 20 upstream of the mixer 14 and the pressure of the fuel gas F in the fuel supply path 11 constant. 12, a fuel supply amount adjustment valve 13 for adjusting the supply amount of the fuel gas F supplied to the combustion chamber 26a via the mixer 14 is provided.

The output shaft 50 is provided with a rotation speed sensor 51 that measures the rotation speed of the output shaft 50 as the rotation speed of the engine body 26.
The ECU 40 adjusts the supply amount of the fuel gas F to the combustion chamber 26a by controlling the opening of the fuel supply amount adjustment valve 13 based on the rotation speed of the engine body 26 measured by the rotation speed sensor 51. By doing so, it functions as a rotational speed maintaining means 42 for maintaining the rotational speed of the engine body 26 at a desired target rotational speed.

The exhaust passage 27 is provided with an oxygen sensor 53 that detects the oxygen concentration of the exhaust gas E.
The ECU 40 adjusts the mixing ratio of the air A to the fuel gas F supplied to the mixer 14 by controlling the opening of the throttle valve 24 based on the oxygen concentration of the exhaust gas E detected by the oxygen sensor 53. Thus, it functions as air-fuel ratio control means 43 that maintains the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 at a desired air-fuel ratio such as the theoretical air-fuel ratio.

  The supercharger 30 supplies the exhaust gas E discharged from the combustion chamber 26 a to the turbine 32 provided in the exhaust passage 27 of the engine body 26, and is combusted by the compressor 31 provided in the intake passage 20 while being connected to the turbine 32. The turbocharger is configured to compress the air-fuel mixture M sucked into the chamber 26a. That is, the supercharger 30 rotates the turbine 32 by the kinetic energy of the exhaust gas E flowing through the exhaust passage 27, and rotates the compressor 31 disposed in the intake passage 20 by the rotational force of the turbine 32. Then, so-called supercharging is performed in which the air-fuel mixture M as fresh air flowing through the intake passage 20 is supplied to the combustion chamber 26a in a compressed state. In addition, when this type of turbocharger 30 is operated at a relatively high output, the supply amount of the exhaust gas E to the turbine 32 increases, so that the turbine 32 and the turbocharger 30 are connected to the turbine 32. The rotational speed of the compressor 31 (hereinafter referred to as “the rotational speed of the supercharger 30”) increases, and as a result, the pressure on the outlet side of the compressor 31, that is, the pressure between the compressor 31 and the throttle valve 24 in the intake passage 20 ( Hereinafter referred to as “supercharging pressure”). On the other hand, when the operation is performed at a relatively low output, the supply amount of the exhaust gas E to the turbine 32 is reduced, so that the rotational speed of the supercharger 30 is lowered, and as a result, the supercharging pressure is lowered.

The emergency generator 28 is connected to the output shaft 50, and the rotational power output from the output shaft 50 is used as a drive source for the emergency generator 28.
A power load 29 is connected to the emergency generator 28 via a power line and a switch 52. For example, the engine body 26 is activated by the ECU 40 that receives an activation command signal from the outside during a power failure, and the output shaft When the switch 52 is switched from an open state (a state in which power flow is interrupted) to a closed state (a state in which power flow is allowed) with the rotation of the motor 50 being performed, a power load is applied to the emergency generator 28. A power generation load corresponding to the power required at 29 is input, and accordingly, a rotational load necessary for rotationally driving the emergency generator 28 with respect to the output shaft 50 is input. Hereinafter, when the switch 52 is switched from the open state to the closed state in the initial stage after starting the engine body 26 in this manner, the rotational load is applied to the output shaft 50 of the engine body 26 is referred to as the initial load application. There is a case.

Furthermore, the outlet side of the compressor 31 in the intake passage 20 (the downstream side of the compressor 31 in the intake passage 20 and the upstream side of the throttle valve 24) and the inlet side (the upstream side of the compressor 31 in the intake passage 20 and the downstream side of the mixer 14). Is connected, in other words, a bypass passage 60 that bypasses the compressor 31 is provided, and the bypass passage 61 is provided with a bypass valve 61 whose opening degree can be adjusted.
The ECU 40 executes a bypass opening process for maintaining the bypass valve 61 in an open state when an initial load is applied to the engine body 26, and performs a bypass closing process for closing the bypass valve after the initial load is applied to the engine body 26. It functions as bypass control means 41 to be executed.

[ Reference form]
Hereinafter, the detailed configuration of the turbocharged engine 100 of the reference embodiment will be described based on FIGS. 2 and 3 together with the processing flow and state transition of the load application method.
When there is a start command to the engine body 26, the ECU 40 starts the engine body 26 while adjusting the opening of the fuel supply amount adjusting valve 13 based on the start command (# 01 in FIG. 2).
Thereafter, the rotational speed maintaining means 42 that the ECU 40 functions is based on the rotational speed of the engine body 26 measured by the rotational speed sensor 51 so that the rotational speed of the engine body 26 becomes a constant target rotational speed. Rotational speed maintenance control for controlling the opening of the supply amount adjusting valve 13 is executed (# 02 in FIG. 2). The ECU 40 continues to execute the rotation speed maintenance control while the engine body 26 is activated.

Next, when there is an initial load application command, the bypass control means 41 in which the ECU 40 functions executes a bypass release process when an initial load is applied to the engine body 26 based on the initial load application command (see FIG. 2 # 03, 04).
In other words, the bypass control means 41 bypasses the compressor 31 at the timing of # 04 in FIG. 3 immediately before the initial load is applied, that is, in the no-load state where the engine output is substantially zero output Q1. The bypass valve 61 is opened in such a form that the opening degree of the bypass valve 61 provided in the bypass path 60 is changed from the closing side opening degree B1 (approximately 0%) to an opening side opening degree B2 larger than the opening degree. Let
Then, since the flow of the air-fuel mixture M in the bypass passage 60 is permitted, the supercharging pressure is reduced from the pressure P2 before the bypass opening process to the pressure P1 lower than that, thereby the inlet side of the compressor 31. The pressure difference between the outlet side pressure (in other words, the supercharging pressure) with respect to the pressure (substantially atmospheric pressure) is reduced, and the rotational load of the compressor 31 is reduced. As a result, the rotational speed of the supercharger is the rotational speed T1 before the bypass process. Therefore, the rotational speed T2 is increased to a higher rotational speed T2.
Further, in order to suppress the fluctuation (decrease) in the engine output accompanying the decrease in the supercharging pressure due to the bypass opening process as described above, the opening degree of the throttle valve 24 is slightly enlarged in accordance with the opening of the bypass valve 61, The outlet side pressure of the throttle valve 24, in other words, the intake pressure to the combustion chamber 26a is maintained constant.

Then, the ECU 40 executes the initial load application in a state where the bypass opening process is executed and the rotational speed of the supercharger 30 is increasing. That is, the emergency generator 28 starts to rotate with the rotational power of the engine body 26 (# 05 in FIG. 2).
At this time, as shown in FIG. 3, the supercharger 30 is driven at a high rotational speed at the timing of initial load application (# 05 in FIG. 2), and the responsiveness to the load becomes high. Therefore, the rotation speed is made to follow well with respect to the input initial load. As a result, in the engine main body 26, the air-fuel mixture M is appropriately supplied following the initial load application, and after the initial load is applied, it is possible to prevent the rotation speed from being greatly reduced and falling into a stall.
Note that the opening degree B2 of the bypass valve 61 expanded by the bypass opening process corresponds to the change in the flow rate of the mixture M in the bypass passage 60 before and after the initial load is applied and the change in the intake amount of the mixture M with respect to the combustion chamber 26a. Is set as appropriate.

  As the initial load is applied to the engine body 26, the rotation speed maintaining means 42 increases the engine output and maintains the rotation speed of the engine body 26. The amount of fuel gas F supplied is increased by increasing the opening. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased.

On the other hand, when the bypass opening process (# 04) is executed and the rotational speed of the compressor 31 is increased, the air-fuel mixture M is discharged from the outlet side of the compressor 31 toward the downstream side at a relatively high speed. become.
Therefore, in this state, when an initial load is applied to the engine body 26 and the opening of the throttle valve 24 disposed on the downstream side of the compressor 31 is increased, immediately after the expansion of the throttle valve 24, the speed is increased. The discharged air-fuel mixture M is filled in the combustion chamber 26a with its strong inertia force.

The bypass control means 41 in which the ECU 40 functions performs a bypass closing process after the initial load is applied to the engine body 26 (# 06 in FIG. 2).
In other words, when the initial load application time has elapsed after the start of the initial load application, it is determined that the initial load application has been completed, and the bypass control unit 41 determines that the timing is # 06 in FIG. The bypass valve 61 is closed by changing the opening degree of the bypass valve 61 provided in the bypass path 60 from the opening degree B2 on the opening side to the opening degree B1 (approximately 0%) on the closing side smaller than the opening degree. Let
Then, since the flow of the air-fuel mixture M in the bypass passage 60 is prohibited, the pressure difference between the outlet side pressure (supercharging pressure) and the inlet side pressure of the compressor 31 becomes large, and the supercharging pressure is bypassed. The pressure rises to a pressure P3 higher than the pressure P2 before the processing, and the air-fuel mixture M is sufficiently compressed by the compressor 31. As a result, the engine efficiency is improved and a more stable operation state is maintained. become.

Further, in this bypass closing process, the bypass control means 41 gradually reduces the opening degree of the bypass valve 61 at a predetermined increase rate as the engine output increases.
Then, the exhaust energy of the exhaust gas E supplied to the turbine 32 increases due to the increase in the engine output in accordance with the increase in the rotational load of the compressor 31 due to the closure of the bypass valve 61. Therefore, even after the initial load is applied, the rotational speed of the supercharger 30 can be maintained in a high state, and a decrease in engine efficiency and a stall due to a sudden blockage of the bypass valve 61 are avoided.
Then, the ECU 40 increases the engine output to the rated output Q2 simultaneously with the execution of the bypass opening process and the bypass closing process (# 07).
Further, in order to suppress the fluctuation (rise) of the engine output accompanying the increase of the supercharging pressure due to the bypass closing process as described above, the opening degree of the throttle valve 24 is slightly reduced in accordance with the closing of the bypass valve 61, The outlet side pressure of the throttle valve 24, in other words, the intake pressure to the combustion chamber 26a is maintained constant.

[Implementation Embodiment
Hereinafter, the detailed configuration of a turbo supercharged engine 100 of implementation form, with reference to FIGS. 4 to 6 will be described in conjunction with process flow and a state transition condition of load application method.
In addition, about the description which overlaps with the said reference form, it may omit.

Similar to the first embodiment, the ECU 40 starts the engine body 26 (# 01 in FIG. 4), and then executes rotation speed maintenance control (# 02 in FIG. 4).
Next, when there is an initial load application command, the bypass control means 41 in which the ECU 40 functions executes a bypass release process immediately before the initial load Q1 is input to the engine body 26 based on the input command. (# 03 in FIG. 4, # 04 in FIGS. 4 and 6).
In other words, the bypass control means 41 bypasses the compressor 31 at the timing of # 04 in FIG. 6 immediately before the initial load Q1 is input, that is, in the no-load state where the engine output is substantially zero. The bypass valve 61 is opened in a form in which the opening degree of the bypass valve 61 provided in the bypass path 60 to be changed is changed from the opening degree I1 (about 0%) on the closing side to the opening degree I3 of the fully open (100%), Reduce pumping loss during the intake stroke.
Further, the opening of the throttle valve 24 is expanded from the opening S1 to a slightly larger opening S2 in accordance with the decrease in the supercharging pressure due to the bypass opening process, and the fluctuation of the engine output is suppressed.

Then, the ECU 40 inputs the initial load Q1 (for example, a load of 40% with respect to the rated load (100% load)) while the bypass opening process is executed and the rotational speed of the supercharger 30 is increasing. Execute (# 05 in FIGS. 4 and 6).
When the initial load Q1 is applied to the engine main body 26, the rotation speed maintaining means 42 increases the engine output and maintains the rotation speed of the engine main body 26. The amount of fuel gas F supplied is increased by increasing the valve opening 13. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased to, for example, the opening degree S5 which is the largest 100% opening degree.

However, even if the opening degree of the throttle valve 24 is fully opened, the engine output is insufficient and the rotational speed of the engine body 26 is less than the target rotational speed Rt when the boost pressure is reduced by the bypass opening process. In some cases (for example, about 100 rpm).
Therefore, when the output of the engine body 26 is insufficient after the initial load is applied (# 05 in FIGS. 4 and 6) and before the bypass closing process is executed (# 06 in FIG. 4), It functions as a correction means for executing a predetermined correction process (# 05-1 in FIG. 4) described later. By executing this correction processing, the output shortage of the engine body 26 is resolved without relying on the increase in the opening of the throttle valve 24, and the rotation speed of the engine body 26 is maintained at the target rotation speed Rt.
Hereinafter, details of the correction processing will be described with reference to FIG.

In this correction processing, first, it is determined whether or not the deviation of the rotational speed of the engine body 26 from the target rotational speed Rt (hereinafter referred to as “rotational speed deviation”) exceeds a predetermined reference value ΔRt (for example, about 100 rpm). (# 11 in FIG. 5).
When the rotational speed deviation exceeds the reference value ΔRt, the opening degree of the bypass valve 61 is changed from the opening degree I3 (about 100%) to a smaller opening degree I2 (about 50%). The image is reduced (# 12-1 in FIGS. 5 and 6).
Then, the air-fuel mixture M is compressed to some extent by the compressor 31, and as a result, the engine output increases moderately.

Further, simultaneously with the reduction of the opening degree of the bypass valve 61 (# 12-1 in FIGS. 5 and 6), the opening degree of the fuel supply amount adjustment valve 13 is increased by a predetermined amount, so that the combustion chamber 26 is inhaled. The air-fuel ratio of the air-fuel mixture M is corrected to the fuel rich side in such a manner that the air ratio of the air-fuel mixture M changes from λ0 (for example, about 1.8) to λ1 (for example, about 1.2) (FIG. 5 and FIG. 5). # 12-2 in FIG.
Then, the amount of fuel input into the combustion chamber 26 per cycle increases, and as a result, the engine output increases moderately.
Then, by executing such correction processing and increasing the engine output, the shortage of output of the engine body 26 is resolved, and the engine rotation speed is maintained at the target rotation speed Rt.

After such correction processing (# 05-1 in FIG. 4) is executed, bypass closing processing (# 06 in FIG. 6) is executed when the engine rotation speed is maintained at the target rotation speed Rt.
That is, after the initial load Q1 is input (# 05 in FIG. 4), the intake bypass valve 61 is closed while the rotation speed of the supercharger 30 is high, and the compression of the air-fuel mixture M by the compressor 31 is started. Therefore, the supercharging pressure rises quickly, and it is prepared for the input of the second load Q2 following the initial load Q1.

Then, after executing the initial load Q1 (# 05 in FIG. 6) and the bypass closing process (# 06 in FIG. 6) in this way, the residual loads Q2 and Q3 that are input following the initial load are input. . Note that FIG. 6 shows an example in which the remaining load following the initial load Q1 is divided into a second load Q2 and a third load Q3 and is input stepwise.
Further, during the remaining loads Q2 and Q3, since the bypass valve 61 is kept closed, the opening degree of the throttle valve 24 gradually increases as the load is applied. Specifically, as the second load Q2 is turned on, the opening of the throttle valve 24 increases from the opening S3 to a larger opening S4, and as the third load Q3 is turned on, the throttle valve 24 opens. The degree is increased from the opening degree S4 to the opening degree S5 which is larger than the opening degree S4.

In the present implementation mode, in FIG. 6, the correction processing (# 12-2), and reduction processing of the opening of the bypass valve 61 to the air-fuel ratio of the fuel-rich side of the air-fuel mixture M which is sucked into the combustion chamber 26 Although the process is started at an earlier stage than (# 12-1 in FIGS. 4 and 6), these processes may be performed simultaneously or in the reverse order.

[Other Embodiments]
Finally, other embodiments of the present invention will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of other embodiments as long as no contradiction arises.
(1) In the above embodiment, the rotation speed maintaining means 42 controls the opening of the fuel supply amount adjusting valve 13 in order to maintain the rotation speed of the engine body 26 at a desired target rotation speed, and the air-fuel ratio control means 43. However, in order to maintain the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 at a desired air-fuel ratio such as the stoichiometric air-fuel ratio, the opening degree of the throttle valve 24 is controlled. The means 42 adjusts the opening degree of the throttle valve 13 to maintain the rotational speed of the engine body 26 at a desired target rotational speed, and the air-fuel ratio control means 43 controls the opening degree of the throttle valve 24 so that the mixer 14 You may comprise so that the air fuel ratio of the air-fuel mixture M produced | generated may be maintained in desired air fuel ratios, such as a theoretical air fuel ratio.

(2) In the above-described embodiment, when the initial load application is completed, it is determined that the initial load application is completed when the initial load application time (fixed time) has elapsed after the initial load is applied to the engine body. did.
However, regarding the determination of completion of the initial load application, the initial load application is completed when fluctuations in the rotational speed of the engine body 26 and the frequency of the generated power of the emergency generator 28 driven to rotate by the engine body 26 are settled. You may comprise so that it may determine.

(3) In the above-described embodiment, the configuration in which the opening degree of the bypass valve 61 is gradually reduced as the engine output increases in the bypass closing process has been described. You may comprise so that it may block | close in steps or at a stretch.

(4) In the above embodiment, the case where the initial load is input after executing the bypass opening process when there is an initial load input command (# 03, 04, # 05 in FIG. 2) has been described. If the initial load command is not input and the initial load is applied, the bypass opening process is unconditionally executed immediately after the engine is started to prepare for the initial load application. It doesn't matter.

  The present invention relates to an engine main body that generates rotational power by compressing and burning an air-fuel mixture of fuel and air in a combustion chamber, and exhaust gas discharged from the combustion chamber to a turbine provided in an exhaust passage of the engine main body. And a turbocharger that compresses fresh air taken into the combustion chamber by a compressor provided in the intake passage while being connected to the turbine, and a rotation that maintains the rotational speed of the engine body at a target rotational speed It can be suitably used as a turbocharged engine provided with a speed maintaining means and a method for loading the same.

13: Fuel supply amount adjusting valve 20: Intake passage 24: Throttle valve 26: Engine body 26a: Combustion chamber 27: Exhaust passage 30: Supercharger 31: Compressor 32: Turbine 41: Bypass control means 42: Rotational speed maintaining means 60 : Bypass passage 61: Bypass valve 100: Turbocharged engine A: Air F: Fuel gas (fuel)
M: Air-fuel mixture

Claims (7)

An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Bypass control for performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, and performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body With means ,
The bypass control means executes a correction process for correcting the opening degree of the bypass valve to the reduction side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. Turbocharged engine equipped with a correction means . An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Bypass control for performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, and performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body With means,
The bypass control means sets the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to a fuel rich side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. A turbocharged engine provided with a correction means for executing a correction process for correcting the pressure . A throttle valve is disposed downstream of the compressor in the intake passage,
The opening degree of the throttle valve according to claim 1 or 2, wherein the opening degree of the throttle valve is expanded by the rotation speed maintaining means executing the rotation speed maintaining control of the engine with the initial load applied to the engine body. Turbocharged engine. The turbocharged engine according to any one of claims 1 to 3, wherein the bypass control means gradually reduces the degree of opening of the bypass valve as the engine output increases in the bypass closing process . The bypass control means executes a correction process for correcting the opening degree of the bypass valve to the reduction side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. The turbocharged engine according to claim 2, further comprising correction means for performing the correction . An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
Performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body,
A turbocharged engine that executes a correction process for correcting the opening degree of the bypass valve to the reduction side when an output shortage of the engine body occurs after the initial load is applied and before the bypass closing process is performed. Loading method. An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
  Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
  A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
  A bypass path connecting the outlet side and the inlet side of the compressor in the intake path, and a bypass valve disposed in the bypass path,
  Performing bypass opening processing for maintaining the bypass valve in an open state when the initial load is applied to the engine body, performing bypass closing processing for closing the bypass valve after the initial load is applied to the engine body,
  A correction process for correcting the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to the fuel rich side when an output shortage of the engine body occurs after the initial load is applied and before the bypass block process is performed. The turbocharged engine load input method to be executed.

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