JP2021080920A - Crosshead type large low-speed turbocharged two-stroke uniflow scavenge internal combustion engine, and method for operating the same - Google Patents

Abstract

To recover performance deterioration due to a change with time.SOLUTION: A large low-speed two-stroke internal combustion engine has an exhaust valve actuating system 46 for actuating exhaust valves, a plurality of cylinders 1 each including a fuel supply system for supplying a first fuel, a pressure sensor for generating an individual cylinder pressure signal, and an exhaust driven turbocharger for compressing scavenging air. A method individually executes, on the basis of the individual cylinder pressure signal, a common set point for all cylinders, and a cylinder individual set point: controlling a fuel quantity in a closed loop; timing start of fuel introduction/injection; and timing closing of an exhaust valve. The cylinder individual set point adjusts the common set point for each cylinder. Another method comprises controlling combustion process parameters individually for each cylinder, and periodically adjusting a common set point of the combustion process parameters for each cylinder as a function of engine operating conditions.SELECTED DRAWING: Figure 4

Description

The matters disclosed in the present application relate to a crosshead type large low speed turbocharged 2-stroke multi-cylinder uniflow scavenging internal combustion engine and a method for operating the same.

A crosshead large low speed turbocharged 2-stroke uniflow scavenging internal combustion engine is typically used as a propulsion system for large vessels or as a prime mover for a power plant.

In modern times this type of institution is completely electronically controlled. That is, both the introduction / injection of fuel and the opening and closing of the exhaust valve can be adjusted by the electronic control system during the operation of the engine so that the operation of the engine conforms to a given operating condition.

The engine is calibrated at the factory to ensure that it meets all the required performance. These performances are, for example, power output, fuel efficiency, emissions, noise and vibration levels, and reliability.

This allows the engine to operate properly and meet performance requirements when shipped. However, over time, due to wear and tear, the engine (at least the cylinder) deviates from the factory specifications. That is, recalibration is required.

In recent years, there has been a demand for the use of alternative fuels in turbocharged large two-stroke compression ignition engines. Such fuels include natural gas, petroleum gas, methanol, coal slurry, mixed fuel of water and oil, petroleum coke and the like.

Some of these alternative fuels have the potential to reduce costs and reduce emissions.

Large low-speed uniflow scavenging turbocharged two-stroke internal combustion engines are typically used to propel large ocean-going cargo ships. For this reason, reliability is extremely important. This type of engine, which uses alternative fuels, can still be said to have been developed relatively recently, and the redundancy of gas-fueled operation is less reliable than that of conventional fueled operation. Stay on the level. The utilization rate of the dual fuel engine is kept low by design when operating on gas fuel. This is to reduce costs. For example, gas fuel systems have low redundancy. If a failure is detected in the gas fuel supply in one cylinder, all cylinders will stop. In the conventional mode using fuel (fuel oil), only the cylinder affected by the failure stops. Conventional fueled operation guarantees reliability. Therefore, it is important to be able to quickly switch from alternative fuels to conventional fuels. This is because conventional fuels are considered to be a safe means to rely on in the event of an emergency.

Therefore, all existing large low speed 2-stroke diesel engines that can use two fuels are for fuel systems for alternative fuel operation, such as gas fuel, and for conventional fuel operation, such as fuel oil. It has a separate fuel system and is designed to operate at maximum output with only conventional fuel.

If a problem occurs while operating on an alternative fuel, for example if the gas pressure drops while operating on gas fuel, it is necessary to be able to quickly switch to conventional fuel operation. .. The ability to quickly and easily switch from conventional fuels to alternative fuels is equally important for cost reductions and emission reductions.

However, when the fuel type changes, the combustion process does not remain the same and the engine needs to be recalibrated for another fuel. For example, the timing and length of fuel injection, the closing timing of the exhaust valve, the control of scavenging pressure, the compression pressure, the maximum cylinder pressure (peak pressure), the average indicated pressure (Mean Indicated Pressure), etc. depend on the type of fuel used. , Needs to be adjusted. This means that a new process balance should be achieved. This is because the properties (calorific value) of gas fuel delivered by a typical gas fuel system can show large fluctuations.

Known engine control systems are unable to satisfactorily achieve this recalibration without human intervention. Also, known control systems take a very long time to achieve proper operating conditions after fuel switching. Or, it lacks accuracy in order to achieve proper operating conditions immediately after switching fuels.

In addition, the large low speed turbocharged two-stroke uniflow scavenging internal combustion engine is calibrated in the factory so that the combustion process of each cylinder of the engine operates according to design criteria over the entire range of engine operating conditions. In the factory, the cylinders are balanced (load balanced). That is, the maximum (peak) pressure or average indicated pressure (load) of the individual cylinders is made as equal as possible. Alternatively, instead of the peak pressure, the average indicated pressure of the individual cylinders is made as equal as possible to ensure the best possible load balance.

But over time, when leaving the factory, wear and tear have different effects on the engine and each cylinder. During use, the cylinder combustion process deviates from the factory specifications and the cylinder balance deteriorates. Such changes result in poor performance and increased emissions over time, so at some point the control system must be recalibrated to attempt to recover performance.

Known control systems for large two-stroke internal combustion engines require human intervention for such recalibration. However, the intervention of manual work means that specialized skills are required. This is because only one parameter (eg, the closing angle of the exhaust valve) affects various other parameters. Institutional operators usually do not have the skills to perform recalibration that requires human intervention. Therefore, in reality, such recalibration is not usually performed. The lack of recalibration results in increased fuel consumption and increased emissions.

Non-Patent Document 1 discloses an engine having a closed-loop fuel control system that provides a common load setpoint for all cylinders. In this engine, cylinder pressure is measured for each cylinder and the fuel injection timing and exhaust valve closure are adjusted accordingly.

Rolle S., Wiesmann A. Combustion Control and Monitoring of two-stroke engines, Wartsila Technical Journal, 2011

Disclosure

Against this background, an object of the present invention is to provide a large low speed turbocharged 2-stroke uniflow scavenging internal combustion engine and a method for operating the same, which solves or at least alleviates the above-mentioned problems. ..

According to the first aspect, this task is accomplished by providing a crosshead large low speed turbocharged two stroke uniflow scavenging internal combustion engine, such as: This institution
A plurality of exhaust valves, an exhaust valve operating system for operating the exhaust valve, a fuel supply system for supplying the first fuel to the related cylinders, and a pressure sensor for generating a cylinder individual pressure signal indicating the pressure in the related cylinders. With a cylinder;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
The cylinder individual pressure signal is received, and the actual operating conditions of the engine are described.
A common torque signal that represents the torque to be produced by the engine,
A common peak pressure signal representing the peak cylinder pressure to be achieved in the cylinder,
A common compression pressure signal representing the compression pressure to be achieved in the cylinder,
With a control unit configured to determine whether to receive;
With
a) The control unit derives a cylinder individual actual torque signal representing a torque generated from a specific cylinder from the cylinder individual pressure signal, and as a function of deviation of the common torque signal from the cylinder individual actual torque signal. The common torque signal is adjusted to obtain a cylinder individual torque signal, and as a function of the cylinder individual torque signal, a specific amount of fuel is supplied to the cylinder to which the cylinder individual torque signal is related. Consists of
b) The control unit derives a cylinder individual actual peak pressure signal representing a peak pressure generated from a specific cylinder from the cylinder individual pressure signal, and deviates from the cylinder individual actual peak pressure signal. As a function of, the common peak pressure signal is adjusted to obtain a cylinder individual peak pressure signal, and as a function of the cylinder individual peak pressure signal, the cylinder to which the cylinder individual peak pressure signal is related is connected. It is configured to determine when to start supplying fuel,
c) The control unit derives a cylinder individual actual compression pressure signal representing the compression pressure generated from a specific cylinder from the cylinder individual pressure signal, and deviates from the cylinder individual actual compression pressure signal. As a function of, the common compression pressure signal is adjusted to obtain a cylinder individual compression pressure signal, and as a function of the cylinder individual compression pressure signal, the exhaust of the cylinder to which the cylinder individual compression pressure signal is related. It is configured to determine when to close the valve.

By individually adjusting the parameters of the combustion process for each cylinder, that is, by creating individual cylinder torque signals, individual cylinder peak pressure signals, and individual cylinder compression pressure signals in the feedback loop, engine wear and tear, Or, even if a situation occurs in which the operating conditions of the cylinders are changed due to other causes, the individual cylinders can be operated correctly according to the original specifications. At the same time, it becomes possible to control the combustion process of the cylinder of the engine without considering the cylinder balance or the cylinder load balance of the entire engine. The controlled method of the engine allows individual cylinders to operate properly without having to worry about cylinder balance (load balance).

In one example of the implementation of the first aspect, the engine is of fuel-led type and has at least element a).

In an example of the implementation of the first aspect, the engine is an Air-LED type and has at least an element c).

In an example of the implementation of the first aspect, the engine is partially fuel-led, partially air-guided, and has at least element a) and element c).

In one example of the implementation of the first aspect, the engine is a dual engine, the fuel supply system is configured to handle at least two different fuels, and the individual cylinders are supplied with the first fuel. At least one fuel valve and at least one fuel valve for supplying a second fuel are provided.

In an example of the implementation of the first aspect, the engine is fuel-leading when operating on the first fuel and air-leading when operating on the second fuel.

In an example of the implementation of the first aspect, the control unit is adapted to receive the required engine speed and the measuring engine speed, and the fuel index (Fuel index) as a function of the deviation of the required engine speed from the measuring engine speed. ) A speed control device (governor) configured to determine the signal is provided.

In an example of the implementation of the first aspect, the control unit is configured to convert the fuel index signal into a common torque signal by applying the fuel index signal to a first predetermined map.

In an example of the implementation of the first aspect, the control unit comprises an output calculation module configured to calculate an engine load signal representing an engine load, wherein the output calculation module is preferably the fuel index. It is made to receive the signal and the measuring engine speed.

In an example of the mounting embodiment of the first aspect, the control unit is configured as follows.
The common peak pressure signal is determined by applying the engine load signal to a second default map. And / or
-The common compression pressure is determined by applying the engine load signal to a third default map.

In an example of the implementation of the first aspect, the control unit is configured to provide a fuel index signal to a profile duration module, which shares the fuel index signal. It is configured to be converted into a fuel supply period signal.

In one example of the implementation of the first aspect, the control unit adjusts the common fuel supply period signal as a function of deviation of the common fuel supply period signal from the cylinder individual torque signal, thereby the cylinder. It is configured to obtain an individual fuel supply period signal.

In an example of the implementation of the first aspect, the control unit is configured to determine a cylinder individual injection profile as a function of the cylinder individual torque signal or as a function of the cylinder individual fuel injection period signal. The fuel supply system supplies fuel to individual cylinders by opening one or more fuel valves according to the cylinder individual injection profile of that cylinder.

In an example of the implementation of the first aspect, the fuel supply system opens one or more fuel valves according to the timing of starting fuel supply to the cylinder determined by the control unit. The supply of fuel to the cylinder is started.

In an example of the mounting embodiment of the first aspect, the control unit is configured as follows.
When the direction of adjustment of the common torque signal is the same as the direction of adjustment for other cylinders, the magnitude of adjustment of the common torque signal is limited to the first threshold value. When the direction of adjustment of the common torque signal is opposite to the direction of adjustment for other cylinders, the magnitude of adjustment of the common torque signal is limited to the second threshold value.
And / or
When the direction of adjustment of the common peak pressure signal is the same as the direction of adjustment for other cylinders, the magnitude of adjustment of the common peak pressure signal is limited to the first threshold value. When the direction of adjustment of the common peak pressure signal is opposite to the direction of adjustment for other cylinders, the magnitude of adjustment of the common peak pressure signal is limited to a second threshold.
And / or
When the direction of adjustment of the common compression pressure signal is the same as the direction of adjustment for other cylinders, the magnitude of adjustment of the common compression pressure signal is limited to the first threshold value. When the direction of adjustment of the common compression pressure signal is opposite to the direction of adjustment for other cylinders, the magnitude of adjustment of the common compression pressure signal is limited to a second threshold.

In an example of the implementation of the first aspect, the second threshold is lower than the first threshold.

In an example of the implementation of the first aspect, at least one of the first to third predetermined maps is preferably based on the test of the relevant institution or based on the test of the same or equivalent institution. It is decided at the factory of the engine. At least one of the first to third default maps preferably comprises an algorithm and / or a table.

In one example of the first aspect of the embodiment, the common torque signal corresponds to the average indicated cylinder pressure of all cylinders, and the individual cylinder torque signal is the average of the particular cylinders involved. Corresponds to the indicated cylinder pressure.

In an example of the mounting embodiment of the first aspect, the control unit comprises a cylinder individual cylinder offset module for each cylinder, the cylinder individual cylinder offset module for the particular cylinder associated with the common torque signal. It is configured to offset one or more of the common peak pressure signal and the common compression pressure signal.

In an example of the mounting embodiment of the first aspect, the cylinder individual offset module is controlled manually or automatically.

In an example of the mounting embodiment of the first side surface, the control unit is configured to individually control each cylinder of the engine without considering the cylinder balance.

In an example of the mounting embodiment of the first aspect,
When the engine has a configuration a), the control unit is configured to continuously calculate the difference between the cylinder individual torque signal and the cylinder individual actual torque signal as an error value, and has a proportional term and an integral term. It is configured to make corrections based on
When the engine has a configuration b), the control unit is configured to continuously calculate the difference between the cylinder individual peak pressure signal and the cylinder individual actual peak pressure signal as an error value, and is configured to have a proportional term and an integral. It is configured to make corrections based on terms,
When the engine has a configuration c), the control unit is configured to continuously calculate the difference between the cylinder individual compression pressure signal and the cylinder individual actual compression pressure signal as an error value, and is configured to have a proportional term and an integral. It is configured to make corrections based on the terms.

In one example of the implementation of the first aspect, the fuel supply system is configured to supply a first fuel and / or a second fuel to the associated cylinder.

According to the second aspect, there is provided a method of operating a crosshead large low speed turbocharged two stroke uniflow scavenging internal combustion engine. Here, the institution
A plurality of exhaust valves, an exhaust valve operating system for operating the exhaust valve, a fuel supply system for supplying the first fuel to the related cylinders, and a pressure sensor for generating a cylinder individual pressure signal indicating the pressure in the related cylinders. With a cylinder;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
The above method comprises
For a particular cylinder of the plurality of cylinders, including controlling at least one combustion process parameter of the cylinder in a closed loop as a function of a cylinder individual compression signal and a cylinder individual setpoint.
Here, the individual cylinder setpoint is an offset of each cylinder from the common setpoint of all cylinders.

By individually adjusting the parameters of the combustion process for each cylinder, that is, by creating individual cylinder torque signals, individual cylinder peak pressure signals, and individual cylinder compression pressure signals in the feedback loop, engine wear and tear, Or, even if a situation occurs in which the operating conditions of the cylinders are changed due to other causes, the individual cylinders can be operated correctly according to the original specifications. At the same time, it becomes possible to control the combustion process of the cylinder of the engine without considering the cylinder balance or the cylinder load balance of the entire engine. The controlled method of the engine allows individual cylinders to operate properly without having to worry about cylinder balance (load balance).

In an example of the embodiment of the second aspect, the at least one combustion process parameter comprises one or more of the following values:
・ Fuel amount;
・ Fuel injection start timing;
・ Exhaust valve closing timing.

In an example of the second aspect embodiment, the closed loop control is performed without any consideration for maintaining cylinder balance.

In one example of the second aspect embodiment, the closed loop control applies corrections based on proportional and integral terms.

In an example of the second aspect embodiment, the common setpoint is
A common torque signal representing the torque to be produced by the engine and / or
A common peak pressure signal representing the peak cylinder pressure to be achieved in the cylinder,
And / or a common compression pressure signal representing the compression pressure to be achieved in the cylinder.

In an example of the embodiment of the second aspect, the closed loop control uses the cylinder pressure measured for each cylinder as a reference value.

In an example of the second aspect embodiment, the cylinder individual average indicated cylinder pressure is derived from the measured cylinder individual cylinder pressure, the cylinder individual peak pressure is derived from the measured cylinder pressure, and the cylinder individual compression pressure. Is derived from the measured cylinder individual pressure.

According to a third aspect, there is provided a method of operating a crosshead large low speed turbocharged two stroke uniflow scavenging internal combustion engine. Here, the institution
A plurality of exhaust valves, an exhaust valve operating system for operating the exhaust valve, a fuel supply system for supplying the first fuel to the related cylinders, and a pressure sensor for generating a cylinder individual pressure signal indicating the pressure in the related cylinders. With a cylinder;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
The cylinder individual pressure signal is received, and the actual operating conditions of the engine are described.
A common torque signal that represents the torque to be produced by the engine,
A common peak pressure signal representing the peak cylinder pressure to be achieved in the cylinder,
A common compression pressure signal representing the compression pressure to be achieved in the cylinder,
With a control unit configured to determine whether to receive;
To be equipped. And the above method
a) From the cylinder individual pressure signal, a cylinder individual actual torque signal representing the torque generated from a specific cylinder is derived, and the common torque signal is used as a function of deviation of the common torque signal from the cylinder individual actual torque signal. Adjust to obtain a cylinder individual torque signal and supply fuel to the corresponding cylinder as a function of the cylinder individual torque signal; and / or
b) From the cylinder individual pressure signal, a cylinder individual actual peak pressure signal representing the peak pressure brought about from a specific cylinder is derived, and as a function of deviation of the common peak pressure signal from the cylinder individual actual peak pressure signal, the said Adjusting the common peak pressure signal to obtain the cylinder individual peak pressure signal and, as a function of the cylinder individual peak pressure signal, determine when to start supplying fuel to the corresponding cylinder; and / or
c) From the cylinder individual pressure signal, a cylinder individual actual compression pressure signal representing the compression pressure generated from a specific cylinder is derived, and as a function of deviation of the common compression pressure signal from the cylinder individual actual compression pressure signal, the said Adjusting the common compression pressure signal to obtain the cylinder individual compression pressure signal and determining when to close the exhaust valve of the corresponding cylinder as a function of the cylinder individual compression pressure signal;
including.

According to the fourth aspect, the following crosshead type large low speed turbocharged 2-stroke uniflow scavenging internal combustion engine is provided. This institution
A plurality of exhaust valves, an exhaust valve operating system for operating the exhaust valve, a fuel supply system for supplying the first fuel to the related cylinders, and a pressure sensor for generating a cylinder individual pressure signal indicating the pressure in the related cylinders. With a cylinder;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
One or more cylinder combustion parameters for each cylinder as a function of the pressure signal of each cylinder and the common setpoint of all cylinders or the individual cylinder setpoint which is the offset of each cylinder from the common setpoint. It is provided with a control unit configured to control the above in a closed loop.

According to the fifth aspect, the following crosshead type large low speed turbocharged 2-stroke uniflow scavenging internal combustion engine is provided. This institution
A plurality of exhaust valves, an exhaust valve operating system for operating the exhaust valve, a fuel supply system for supplying the first fuel to the related cylinders, and a pressure sensor for generating a cylinder individual pressure signal indicating the pressure in the related cylinders. With a cylinder;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
With a control unit configured to control at least one of the combustion process parameters, fuel volume, fuel injection start timing, and exhaust valve closing timing for a particular cylinder;
The control unit
By periodically adjusting a common setpoint for combustion process parameters or individual cylinder setpoints for each cylinder, the combustion process parameters for each of the plurality of cylinders can be set as a function of the operating conditions of the engine. Control individually,
Calculate the average of the individual cylinder adjustments of the combustion process parameters over multiple cylinders.
In one cycle of the combustion process parameters, the adjustment is limited to the calculated mean plus or minus default maximum deviation.
It is configured as follows.

By providing a limiter function, a specific cylinder individual adjustment is prevented from exceeding an undesired range. Also, under normal conditions, large adjustments are allowed and very large adjustments caused by errors are suppressed. Therefore, it is possible to avoid damage and interruption of operation.

In an example of an implementation of the fifth aspect, the control unit defines the calculated mean plus or minus window of the default maximum deviation and adjusts the combustion process parameters cylinder-specifically in one cycle. It is configured to limit adjustments within the window.

In an example of the fifth aspect implementation, the window has a first range in the positive direction and a second range in the negative direction from the calculated average.

In one example of the fifth aspect implementation, the window is specific to the combustion process parameters.

In an example of the implementation of the fifth aspect, the positive range has a first predetermined size, the negative range has a second default size, and the first default size. The size does not have to be the same as the second predetermined size.

In an example of the implementation of the fifth aspect, the control unit may be an average of individual cylinder adjustments over a plurality of cylinders of combustion process parameters in one cycle, or a plurality of periodic adjustments of the combustion process parameters. It is configured to calculate the average over the cycle.

In one example of the implementation of the fifth aspect, the adjustment of the combustion process parameters is an adjustment for a single cycle.

In an example of the fifth aspect implementation, the at least one combustion process parameter comprises one or more of the following values:
・ Fuel amount;
・ Fuel injection start timing;
・ Exhaust valve closing timing.

In an example of the implementation of the fifth aspect, the cylinder-specific setpoint of the combustion process parameter is an offset from the common setpoint of the combustion process parameter.

In an example of the mounting embodiment of the fifth aspect, the operating conditions of the engine are engine speed, engine load, cylinder peak pressure, cylinder compression pressure, cylinder average indicated pressure, scavenging pressure, fuel type, immediate humidity, environment. One or more of the temperatures.

According to a sixth aspect, there is provided a method of operating a crosshead large low speed turbocharged two stroke uniflow scavenging internal combustion engine. Here, the institution
With a plurality of cylinders each comprising an exhaust valve, an exhaust valve operating system for operating the exhaust valve, and a fuel supply system for supplying a first fuel to the related cylinders;
With an exhaust-driven turbocharger that pressurizes scavenging for the cylinder;
The above method is:
Controlling at least one of the combustion process parameters, fuel amount, fuel injection start timing, and exhaust valve closing timing for each cylinder;
By periodically adjusting a common setpoint for combustion process parameters or individual cylinder setpoints for each cylinder, the combustion process parameters for each of the plurality of cylinders can be set as a function of the operating conditions of the engine. To control individually;
To calculate the average of the individual cylinder adjustments;
To define a window around the calculated average;
In one cycle of the combustion process parameters, limiting the adjustment to the calculated mean plus or minus default maximum deviation;
Including methods.

Fuel valves and engines pursuant to the disclosure herein and further objectives, features, advantages and properties will be further clarified by the detailed description below.

In the following detailed description portion of the present specification, the invention will be described in more detail with reference to exemplary embodiments shown in the drawings.
FIG. 5 is a front view of a large two-stroke diesel engine according to an exemplary embodiment. It is a side view of the large two-stroke engine of FIG. It is a schematic representation of the large two-stroke engine of FIG. It is a block diagram or a circuit diagram of the Example of the control part of the engine of FIG. It is a block diagram or circuit diagram of another embodiment of the control part of the engine of FIG. It is a block diagram or circuit diagram of still another embodiment of the control part of the engine of FIG.

Detailed explanation

In the following detailed description, the compression ignition internal combustion engine will be described with reference to the large low speed 2-stroke turbocharged (diesel) internal combustion engine of the embodiment. Figs. 1 to 3 show a turbocharged large low-speed 2-stroke diesel engine. This engine has a crankshaft 8 and a crosshead 9. FIG. 3 is a schematic representation of a turbocharged large low-speed 2-stroke diesel engine together with its intake system and exhaust system. In an embodiment, the engine has six cylinders 1 in series. A turbocharged large low speed 2-stroke diesel engine typically has 4 to 14 cylinders arranged in series. These cylinders are supported on the engine frame 11. Further, such an engine can be used, for example, as a main engine of an ocean-going vessel or a fixed engine for operating a generator in a power plant. The total output of the engine can be, for example, 1000 kW to 110,000 kW.

The diesel (compression ignition) engine or Otto (spark ignition) engine in this embodiment is a two-stroke uniflow scavenging engine, a scavenging port 18 is provided in the lower region of the cylinder 1, and an exhaust valve is provided in the center of the top of the cylinder 1. Is arranged. The scavenging air is guided to the scavenging port 18 of each cylinder 1 through the scavenging receiver 2. When the piston 10 in the cylinder 1 compresses the scavenging air, fuel is injected through the fuel injection valve 50.51 in the cylinder cover 22 to generate combustion, and exhaust gas is generated. When the exhaust valve 4 is opened, the exhaust gas flows to the exhaust receiver 3 through the exhaust duct provided in the cylinder 1, and further advances to the turbine 6 of the turbocharger 5 through the first exhaust pipe 19. From there, the exhaust gas flows through the second exhaust pipe 25 to the economizer 20 and is further discharged into the atmosphere from the outlet 21. The turbine 6 drives the compressor 7 via a shaft. Outside air is supplied to the compressor 9 through the air intake port 12. The compressor 7 sends the compressed scavenging air to the scavenging pipe 13 connected to the scavenging receiver 2.

The scavenging pipe 13 passes through an intercooler 14 for cooling the scavenging air. In one embodiment, the scavenging air exiting the compressor is approximately 200 ° C. and is cooled by an intercooler from 36 ° C. to 80 ° C.

The cooled scavenging air passes through an auxiliary blower 16 driven by an electric motor 17. The auxiliary blower 16 compresses the scavenging airflow when the compressor 7 of the turbocharger 5 is unable to provide sufficient pressure for the scavenging receiver 2, i.e. when the engine is underloaded or partially loaded. When the engine load is high, the turbocharger compressor 7 can supply a fully compressed scavenger so that the auxiliary blower 16 is bypassed by the check valve 15.

The piston is connected to the crosshead 9 by a piston rod. The crosshead 9 is connected to the crankshaft 8 by a connecting rod. The rotation speed and position of the crankshaft 8 are measured by the sensor 40. The engine speed signal measured by the sensor 40 is sent to the control unit 55 through, for example, a signal line.

Each cylinder 1 is provided with one exhaust valve 4. In addition, two or more fuel valves 50 and a pressure sensor 42 are also provided. The pressure signal for each cylinder by the pressure sensor 42 is also sent to the control unit 55.

The engine of the embodiment is a dual engine, in which two or more fuel valves 50 are dedicated to the first fuel and two or more fuel valves 50 are dedicated to the second fuel. is there. In another example, two or more fuel valves are shared for the two types of fuel.

The fuel valve 50 is controlled by the control unit 55. For example, the control unit 55 determines when the fuel valve is open and how long it has been in the open state. In some embodiments, the opening profile of the fuel valve 50 is also determined. The fuel valve 50 is part of the fuel supply system 30. The signal for opening and closing the fuel valve 50 can be a fluid signal or a hydraulic signal. In the embodiment in which the signal for opening / closing the fuel valve 50 is a fluid signal, for example, a hydraulic signal, the control unit 55 sends an electronic signal to the electronic control valve or the pump, and the hydraulic signal is transmitted from the electronic control valve or the pump to the fuel valve 50. It may be sent.

In some embodiments, the fuel supply system 30 is configured to be capable of supplying at least two different types of fuel. In some embodiments, one of these two fuels is a fuel oil, such as heavy oil or methanol. In some embodiments, one of these two fuels is a gas fuel, such as petroleum gas or natural gas. In some embodiments, the gas fuel is introduced or injected into the cylinder in a gaseous state. In some embodiments, the gas fuel is introduced or injected into the cylinder in a liquid state.

In some embodiments, the engine is fuel-led. In a fuel-led or gas-led combustion process, the amount of fuel weighed is determined as a function of the duty point of the internal combustion engine and a specific target value for the output and / or speed of the internal combustion engine. To. The fuel-led combustion process is a specific application during variable speed operation of an internal combustion engine, which is an application of a solitary internal combustion engine during engine start-up or when the internal combustion engine is idling. The engine control system includes an output control unit and / or a speed control unit. Engines that operate only according to the diesel process are fuel-led engines, whether the fuel is liquid fuel or gas fuel. Fuel is typically injected shortly after top dead center (TDC) and ignites as soon as it is injected. Therefore, in a fuel-led engine, the fuel injection amount is the most important control parameter.

In some embodiments, the engine is air-led. In an air-led combustion process, the amount of fuel weighed is determined, for example, as a function of the duty point of the internal combustion engine and a particular target value for the air-fuel ratio. This is to avoid the problem of knocking (abnormal early combustion) and specific scavenging pressure (especially specific compression pressure). Therefore, the engine control system usually has a compression pressure control unit. Engines that operate only according to the Otto process are air-led engines, regardless of fuel type. For this reason, compressed air pressure is the most important control parameter in air-led engines.

In some embodiments, the engine is a mixture of air-led and fuel-led. An example of such an engine is one that introduces a first amount of fuel into the combustion chamber before the compression stroke and injects an additional second amount of fuel into the combustion chamber near top dead center (TDC). is there. In the combustion chamber, injection of a second amount of fuel initiates ignition of both the first amount of fuel and the second amount of fuel. In a large two-stroke engine, injection near the TDC is usually performed immediately after the TDC. In this engine, both the amount of fuel injected and the compression pressure are the most important control parameters, and which of these parameters is important depends on the load and speed of the engine.

In one embodiment, the engine is a dual engine, fuel-leading when operating on a first fuel, and air-leading when operating on a second fuel.

An exhaust valve actuator 46 is provided for each exhaust valve 4. In some embodiments, the exhaust valve actuator 46 is a hydraulic actuator that receives a command from an electronic signal from the control unit 55.

One or more combustion process parameters of the combustion process of the cylinder 1 are controlled by the control unit 55. The combustion process parameter is, for example, at least one of a fuel amount, a fuel injection / introduction start timing, and an exhaust valve closing timing. The amount of fuel, which is the combustion process parameter, correlates with the combustion of cylinder 1 in relation to the torque provided by the engine. The fuel injection start timing, which is the combustion process parameter, correlates with the peak pressure of the associated cylinder. (This is especially true for engines that operate according to the diesel principle, not so much for engines based on the Otto principle where fuel is "introduced" rather than "injected".) Exhaust, the combustion process parameter. The valve closing timing correlates with the compression pressure of the associated cylinder.

FIG. 4 shows a first embodiment of the control unit 55. In one embodiment, the control unit 55 includes an engine control unit and a plurality of cylinder control units.

The control unit 55 receives a set of velocities (eg, a desired engine speed), eg, from a ship bridge. The control unit 55 also receives an engine speed signal from the sensor 40. Then, the desired engine speed is compared with the measured engine speed to obtain a speed deviation signal. The control unit 55 includes a governor (speed control device) to which a speed deviation signal is provided. The governor is configured to determine the fuel index as a function of the deviation of the desired engine speed from the measured engine speed. That is, the governor is configured to determine the fuel index as a function of the speed deviation signal. The fuel index signal is a signal indicating the amount of fuel to be introduced / injected to achieve the desired engine speed. The amount of fuel to be injected directly correlates with the magnitude of torque produced by the engine.

The control unit 55 has information on an index / common torque signal conversion module configured to convert the fuel index into a common torque signal by applying the fuel index to a first predetermined map. The common indicated torque / index can be considered to be proportional to the common average indicated pressure.

In the present specification, the expression "common" means that it can be applied to all cylinders.

The first default map is obtained from the test. For example, it is obtained in a factory test facility where the engine is developed and / or assembled. In some embodiments, the first default map has a table or algorithm that relates the fuel index to a common indicated torque.

One cylinder control unit is associated with each of the cylinders 1. The common torque signal is sent to each cylinder control unit.

The control unit 55 includes an output calculation module (load calculation unit) configured to calculate an engine load signal indicating an engine load. In some embodiments, the engine load signal represents the actual engine load relative to the maximum engine load (eg, maximum continuous rating). The output calculation module receives the instruction signal and the measured engine speed. In some embodiments, the load calculation module multiplies the fuel index by the engine speed and the result by a predetermined factor. This default factor is obtained from test or empirical values and multiplied to convert to relative engine load (ie, the percentage of maximum continuous rating).

The control unit 55 determines the common peak pressure by applying the engine load signal to the second default map, and determines the common compression pressure signal by applying the engine load signal to the third default map. It is equipped with an engine operation mode module configured as described above.

These second and third default maps are also obtained from the test. For example, it is obtained in a factory test facility where the engine is developed and / or assembled. In some embodiments, the second default map comprises a table or algorithm relating the peak pressure to the engine load, and the third default map comprises a table or algorithm relating the common pressure to the engine load. The second and third default maps may take into account some other parameters. For example, parameters such as environmental pressure, environmental temperature, engine speed, etc. may be taken into consideration, and offsets for friction loss, etc. may be included.

The common peak pressure signal and the common compression pressure signal may be sent to all cylinder control units.

Each cylinder control unit receives the cylinder pressure measured for the cylinder from the pressure sensor 42 of the cylinder 1 that it controls.

From the cylinder individual pressure signal received from the pressure sensor 42 of the cylinder 1 controlled by the cylinder control unit, the actual maximum pressure of the cylinder (actual maximum pressure of each cylinder) and the actual average indicated pressure of the cylinder ( Cylinder individual actual average indicated pressure) is configured to be calculated. Then, the cylinder individual actual average indicated pressure is expressed as the cylinder individual actual torque.

Preferably, the cylinder individual actual pressure value is determined from the arithmetic mean. Particularly preferably, it is determined from the median of a plurality of consecutive pressure measurements (eg, pressure measurements over multiple engine cycles). The number of engine cycles may be, for example, 5 to 50, preferably about 10.

In order to obtain good signal quality, i.e. high control performance, the cylinder individual pressure signal from the cylinder is the cylinder over 5 to 50 engine cycles (preferably 7 to 15 combustion cycles). The individually measured pressure signals are time-filtered.

Therefore, the individual cylinder pressure is the result of statistical evaluation of the pressure measurement by the pressure sensor 42 of the cylinder 1.

The control unit is configured to adjust the common torque signal as a function of deviation of the common torque signal from the cylinder individual actual torque signal to obtain a cylinder individual torque signal. In addition, the cylinder control unit continuously (or intermittently) calculates the difference between the individual cylinder torque and the individual cylinder actual torque as an error value for the cylinder 1 that it controls, and corrects it based on the proportional term and the integral term. Apply (PI control) to obtain a cylinder individual torque signal to form a closed loop control for the cylinder.

In some embodiments, the control unit 55 is configured to receive one or more of a common torque adjustment amount, a common peak pressure adjustment amount, and a common compression pressure adjustment amount. In this embodiment, the control unit 55 determines the average of the adjustment amounts of the common torque of all the cylinders, the average of the adjustment amounts of the common peak pressures of all the cylinders (mean, average), and the adjustment amounts of the compression pressures of all the cylinders. It is configured to determine one or more of the averages.

In this embodiment, the control unit 55 allows each cylinder control unit to set a maximum adjustment amount within one window for one or more of the cylinder individual torque, the cylinder individual peak pressure, and the cylinder individual compression pressure. Here, the window is defined by an adjustment amount having an average value of plus or minus a predetermined size. For example, the adjustment window is a calculated average plus or minus 5 bar. In this example, when the average value of the cylinder individual peak pressure adjustment amount of all cylinders is 2 bar, each cylinder control unit changes the cylinder individual peak pressure adjustment amount between -3 bar and 7 bar. Is allowed.

The limiter sets a limit on the maximum correction amount of the common torque signal. When the correction of the common torque signal is directed in the same direction in all the cylinders 1, the limiter allows the maximum correction amount up to the first threshold value. When the correction of the common torque signal is not directed in the same direction among the plurality of cylinders 1, the limiter allows a maximum correction amount up to a second threshold value lower than the first threshold value. This prevents false signals from destabilizing the system. Large corrections are allowed if all cylinders 1 have similar changes.

In this way, the control unit 55 calculates the average value of the adjustment amount of the torque signal for each cylinder over all the cylinders, and calculates the adjustment amount of the torque signal for each cylinder in one cycle, plus or minus the calculated average value. Limit to the default maximum deviation value.

The control unit 55 defines a window of the calculated average value plus or minus the predetermined maximum deviation value, and is configured to limit individual cylinder adjustments in one cycle of the torque signal to adjustments within the window. .. This window has a first range in the positive direction and a second range in the negative direction from the average value of the calculated torque signal adjustment amount. This window is for torque signals and for other combustion process parameters (peak pressure and compression pressure). The positive range has a first default magnitude and the negative range has a second default magnitude. These sizes can be determined, for example, from a test run in a factory. The window should be wide enough to accommodate the large adjustments that would normally occur. However, the adjustments that can be caused by errors (eg, sensor signal errors, etc.) should be narrow enough to eliminate them.

The control unit 55 calculates the average value of the adjustment amount of each cylinder for the torque signal over a plurality of cylinders over one cycle or over a plurality of cycles of the periodic adjustment of the torque signal. It is configured as follows. In some embodiments, the adjustment of combustion process parameters is for a single cycle.

The injection profile module converts a cylinder-specific torque signal into a cylinder-specific fuel valve profile signal. The combustion profile module associates the cylinder individual torque signal with the injection profile by applying the cylinder individual torque signal to a fourth predetermined map. This fourth map has an algorithm and / or look-up table obtained from the test. The individual cylinder fuel valve profile is sent to the fuel valve 50 of the corresponding cylinder, instructing the fuel valve 50 to open and close according to that profile, i.e. to achieve the fuel valve opening length and profile shape according to that profile. Will be done. The fuel valve 50 supplies the amount of fuel for each cylinder to the cylinder 1 in response to the fuel valve profile signal of the cylinder control unit of the cylinder 1 to which the fuel valve 50 is related.

The cylinder control unit is configured to adjust the common peak pressure signal as a function of deviation of the common peak pressure signal from the cylinder individual actual peak pressure signal, thereby obtaining the cylinder individual peak pressure signal. The cylinder control unit continuously (or intermittently) calculates the difference between the individual cylinder peak pressure and the individual cylinder actual pressure as an error value for the cylinder 1 that it controls, and corrects it based on the proportional term and the integral term. Apply (PI control) to obtain a cylinder individual peak pressure signal to form a closed loop control for the cylinder.

As previously described for torque signals, the limiter for peak pressure imposes a limit on the maximum amount of correction for the common peak pressure signal. When the correction of the common peak pressure signal is directed in the same direction in all the cylinders 1, the limiter allows the maximum correction amount up to the first threshold value. When the correction of the common peak pressure signal is not directed in the same direction among the plurality of cylinders 1, the limiter allows the maximum correction amount up to a second threshold value lower than the first threshold value. This prevents false signals from destabilizing the system. Large corrections are allowed if all cylinders 1 have similar changes.

The peak pressure module converts a cylinder-specific peak pressure signal into a cylinder-specific fuel injection timing signal. Here, the peak pressure module applies the cylinder individual peak pressure signal to the fifth default map. A fifth default map may include an algorithm and / or look-up table that relates the peak pressure to the start of fuel introduction / injection. This algorithm and / or look-up table of the fifth default map may be obtained from the test.

The cylinder individual fuel injection timing signal is sent to the fuel valve 50 of the corresponding cylinder to instruct the fuel valve 50 when to start opening the valve. That is, the timing (angle) at which fuel introduction / injection is started is instructed. The fuel valve 50 starts the introduction / injection of the fuel amount for each cylinder into the cylinder 1 in response to the injection timing signal of the cylinder control unit of the cylinder 1 to which the fuel valve 50 is related.

The cylinder control unit is configured to adjust the common compression pressure signal as a function of deviation of the common compression pressure signal from the cylinder individual actual compression pressure signal, thereby obtaining the cylinder individual compression pressure signal. The cylinder control unit continuously (or intermittently) calculates the difference between the cylinder individual compression pressure and the cylinder individual actual compression pressure as an error value for the cylinder 1 that it controls, and corrects it based on the proportional term and the integral term. (PI control) to obtain a cylinder individual compression pressure signal to form a closed loop control for the cylinder.

As previously described for torque and peak pressure signals, the compression pressure limiter sets a limit on the maximum amount of correction for the common compression pressure signal. When the correction of the common compression pressure signal is directed in the same direction in all the cylinders 1, the limiter allows the maximum correction amount up to the first threshold value. When the correction of the common compression pressure signal is not directed in the same direction among the plurality of cylinders 1, the limiter allows the maximum correction amount up to a second threshold value lower than the first threshold value. This prevents false signals from destabilizing the system. Large corrections are allowed if all cylinders 1 have similar changes.

The compression pressure module converts the compression pressure signal of each cylinder into the exhaust valve closing timing signal of each cylinder. Here, the compression pressure module applies the cylinder individual compression pressure signal to the sixth default map. A sixth default map may include an algorithm and / or look-up table that relates the compression pressure to the closing of the exhaust valve 4. This algorithm and / or look-up table of the sixth default map may be obtained from the test.

The cylinder individual exhaust valve closing timing signal is sent to the fuel valve 50 of the corresponding cylinder, and instructs the exhaust valve actuator 46 when to close the exhaust valve 4. That is, the timing (angle) for closing the exhaust valve 4 is instructed. The exhaust valve 4 of the cylinder 1 is closed in response to the exhaust valve closing timing signal of the cylinder control unit of the cylinder 1.

Depending on the embodiment, the adjustment amount of the cylinder individual torque signal (average indicated pressure), the adjustment amount of the cylinder individual peak pressure, the adjustment amount of the cylinder individual and the cylinder individual compression pressure are transmitted to the control unit 55 to adjust the average average indicated pressure. The amount, average peak pressure adjustment amount, and average compression pressure adjustment amount are calculated. Adjustments are made cyclically. For example, the engine rotation may be performed once, twice, five times, ten times, or the like. The average value of the combustion process parameters for all cylinders is also calculated periodically. Preferably, it is calculated at the same period as the adjustment period. Then, the control unit 55 sets a limit on the adjustment amount of each cylinder of each combustion process parameter based on the above average value of each combustion process parameter. This limit may be in the form of a calculated mean plus or minus the default maximum deviation. The default maximum deviation value in the positive direction may differ from the default maximum deviation value in the negative direction.

For this reason, windows are formed around the average of the individual combustion process parameters. The above-mentioned default positive deviation value and negative deviation value are determined for each combustion process parameter. If the average of the torque, peak pressure, and compression pressure adjustments is large, the integrator windup may be variable so that large adjustments are allowed.

The cylinder control unit is configured to individually control the cylinder 1 of the engine without considering the cylinder balance, that is, without considering maintaining the cylinder balance. Therefore, each cylinder 1 provides cylinder-specific feedback loop control for cylinder-specific average indicated pressure (torque) and / or cylinder-specific feedback loop control for cylinder-specific peak pressure. And / or operate according to design specifications by providing cylinder-specific feedback loop control for cylinder-specific compression pressure.

Since all cylinders 1 operate according to the design specifications, it is not necessary to consider the cylinder balance. This feature is particularly beneficial for dual fuel engines and after changing fuel types. In conventional engines, manual recalibration after a fuel change was required to properly operate the engine after a fuel change. The controls disclosed herein eliminate the need for manual recalibration after fuel changes. In particular, peak pressure and torque are very important during the change from fuel oil to secondary fuel (eg gas). These are automatically adjusted / maintained in good condition by the disclosed controls.

However, in some situations, one or more cylinders may have to behave differently from the design specifications. For example, the cylinder 1 may be in a state where it is determined that the risk of scuffing (seizure) of the cylinder liner is extremely high. This can happen when the cylinder is not sufficiently lubricated. Cylinders that are scuffed or have signs that scuffing is expected to occur if the load is not reduced will need to be reduced.

Therefore, in the example of the control unit shown in the embodiment of FIG. 5, each cylinder control unit includes a cylinder offset module for each cylinder for the related cylinder 1. In this embodiment, the same components and features as those already described or illustrated are designated by the same reference numerals as before. The control unit 55 in this embodiment is essentially the same as that of the embodiment of FIG. 4, except that a cylinder individual offset module is added.

The individual cylinder offset module is configured to offset one or more of a common torque signal, a common peak pressure signal, and a common compression pressure signal for a particular cylinder 1 associated with it. This offset may be introduced by the operator or may be introduced automatically. For example, it may be automatically introduced based on a signal from a sensor that prompts the control unit 55 or the cylinder control unit to set an offset for a specific cylinder 1. For example, knocking in a specific cylinder may be detected by a sensor. In response to such a knocking sensor, the control unit 55 may reduce the compression pressure of a particular cylinder to lower the temperature of the combustion chamber to reduce the risk of knocking. Therefore, the cylinder individual offset is introduced for a particular cylinder. Further, in this embodiment, the control unit 55 is configured to increase the air-fuel ratio by reducing the amount of fuel. This is done by applying an offset for the amount of fuel injected through the cylinder-specific offsets.

Therefore, the cylinder offset module outputs a cylinder individual torque set point, a cylinder individual peak pressure set point, and a cylinder individual compression pressure set point. These cylinder individual set points are adjusted in the same manner as in the embodiment of FIG. That is, it is adjusted as a function of the difference between the cylinder individual actual torque, the cylinder individual actual peak pressure, and the cylinder individual actual compression pressure of each cylinder so as to reach the cylinder individual torque, the cylinder individual peak pressure, and the cylinder individual compression pressure. To be done.

FIG. 6 represents another embodiment of the control unit 55. In this embodiment, the same components and features as those already described or illustrated are designated by the same reference numerals as before.

The control unit 55 in this embodiment is essentially the same as that of the embodiment of FIG. 5 except that a fuel index / profile duration conversion module is added. The fuel index / profile duration of action conversion module is configured to convert the fuel index signal into a common profile duration of action signal.

Each cylinder control unit is configured to receive a common profile action period signal. The cylinder control unit is configured to adjust the common fuel supply period signal as a function of deviation of the common fuel supply period signal from the cylinder individual torque signal, thereby obtaining a cylinder individual fuel profile action period signal.

The addition of a common profile duration signal improves engine reliability against variations in fuel quality. In particular, the properties of gas fuels can vary significantly, for example LCV (Low Calorific Value) can vary between 30-50%.

In this embodiment, the common torque signal corresponds to the average indicated cylinder pressure of all cylinders and the individual cylinder torque signal corresponds to the average indicated cylinder pressure of the particular cylinder involved.

Many aspects and implementations have been described with some examples. However, considering the specification, drawings, and claims of the present application, those skilled in the art have many variations in carrying out the inventions described in the claims in addition to the described examples. You will be able to understand and embody that. The terms "prepare," "have," and "include" in the claims do not preclude the existence of elements or steps that are not described. Even if it is not explicitly stated that the number of elements described in the claims is plural, it does not exclude the existence of multiple elements. The functions of some of the elements described in the claims may be performed by a single processor, controller, or other unit. Even if some matters are described in separate dependent claims, it does not exclude the combination of these, and the combination can be profitable.

The symbols used in the claims should not be construed as limiting the scope of the invention. Unless otherwise stated, the drawings are intended to be read with the specification and are part of the entire disclosure of this application.

Claims (40)

A crosshead type large low-speed turbocharged 2-stroke uniflow scavenging internal combustion engine (9).
An exhaust valve (4), an exhaust valve operating system (46) for operating the exhaust valve, a fuel supply system (30) for supplying the first fuel to the related cylinders, and a cylinder individual pressure signal indicating the pressure in the related cylinders. With a plurality of cylinders (1) each comprising a pressure sensor (42) to generate;
With an exhaust driven turbocharger (5) that pressurizes scavenging for the cylinder;
The cylinder individual pressure signal is received, and the actual operating conditions of the engine are described.
A common torque signal that represents the torque to be produced by the engine,
A common peak pressure signal representing the peak cylinder pressure to be achieved in the cylinder,
A common compression pressure signal representing the compression pressure to be achieved in the cylinder,
With a control unit (55) configured to determine whether to receive;
With
a) The control unit derives a cylinder individual actual torque signal representing a torque generated from a specific cylinder from the cylinder individual pressure signal, and as a function of deviation of the common torque signal from the cylinder individual actual torque signal. The common torque signal is adjusted to obtain a cylinder individual torque signal, and as a function of the cylinder individual torque signal, a specific amount of fuel is supplied to the cylinder to which the cylinder individual torque signal is related. Consists of
b) The control unit derives a cylinder individual actual peak pressure signal representing a peak pressure generated from a specific cylinder from the cylinder individual pressure signal, and deviates from the cylinder individual actual peak pressure signal. As a function of, the common peak pressure signal is adjusted to obtain a cylinder individual peak pressure signal, and as a function of the cylinder individual peak pressure signal, the cylinder to which the cylinder individual peak pressure signal is related is connected. It is configured to determine when to start supplying fuel,
c) The control unit derives a cylinder individual actual compression pressure signal representing the compression pressure generated from a specific cylinder from the cylinder individual pressure signal, and deviates from the cylinder individual actual compression pressure signal. As a function of, the common compression pressure signal is adjusted to obtain a cylinder individual compression pressure signal, and as a function of the cylinder individual compression pressure signal, the exhaust of the cylinder to which the cylinder individual compression pressure signal is related. Configured to determine when to close the valve,
organ. The engine according to claim 1, which is a fuel-leading type or an air-leading type. The engine according to claim 1, which is partially fuel-leading and partially air-leading. The engine according to any one of claims 1 to 3, which is a dual engine, wherein the fuel supply system (30) is configured to handle at least two different fuels, and each of the plurality of cylinders has a first. An engine provided with at least one fuel valve (50) for supplying one fuel and at least one fuel valve (50) for supplying a second fuel. The engine according to claim 4, wherein it is a fuel-leading type when operating on the first fuel and is an air-leading type when operating on the second fuel. The control unit comprises a governor configured to receive the required engine speed and the measuring engine speed and to determine the fuel index signal as a function of the deviation of the required engine speed from the measuring engine speed. The institution described in any of 1 to 5. The engine according to claim 6, wherein the control unit is configured to convert the fuel index signal into the common torque signal by applying the fuel index signal to a first predetermined map. The control unit comprises an output calculation module configured to calculate an engine load signal representing the load of the engine, which preferably receives the fuel index signal and the measuring engine speed. , The institution according to claim 6 or 7. The control unit
• The common peak pressure signal is determined and / or by applying the engine load signal to a second default map.
The common compression pressure is determined by applying the engine load signal to a third default map.
The institution according to claim 8. The control unit is configured to provide a fuel index signal to a profile action period module, the profile action period module is configured to convert the fuel index signal into a common fuel supply period signal, claim 1. Institutions listed in any of 9 to 9. The control unit is configured to adjust the common fuel supply period signal as a function of deviation of the common fuel supply period signal from the cylinder individual torque signal, thereby obtaining a cylinder individual fuel supply period signal. , The institution according to claim 10. The control unit is configured to determine a cylinder individual injection profile as a function of the cylinder individual torque signal or as a function of the cylinder individual fuel injection period signal, the fuel supply system according to the cylinder individual injection profile. The engine according to any one of claims 1 to 11, wherein one or more fuel valves (50) of the cylinder to which the cylinder individual injection profile is related are opened to supply fuel to the cylinder. The fuel supply system starts supplying the specific amount of fuel by opening one or more fuel valves according to the start of the timing of supplying the specific amount of fuel determined by the control unit. The institution according to any one of claims 1 to 12. The control unit
When the adjustment direction of the common torque signal is the same as the adjustment direction for other cylinders, the magnitude of the adjustment of the common torque signal is limited to the first threshold value, and the adjustment direction of the common torque signal is limited to the first threshold value. Is configured to limit the magnitude of the adjustment of the common torque signal to a second threshold when is opposite to the direction of adjustment with respect to the other cylinders and / or
When the adjustment direction of the common peak pressure signal is the same as the adjustment direction for other cylinders, the magnitude of the adjustment of the common peak pressure signal is limited to the first threshold value, and the adjustment of the common peak pressure signal is performed. Is configured to limit the magnitude of the adjustment of the common peak pressure signal to a second threshold and / or when the direction of is opposite to the direction of adjustment for the other cylinder.
When the adjustment direction of the common compression pressure signal is the same as the adjustment direction for other cylinders, the magnitude of the adjustment of the common compression pressure signal is limited to the first threshold value, and the adjustment of the common compression pressure signal is performed. Is configured to limit the magnitude of the adjustment of the common compression pressure signal to a second threshold when the direction of is opposite to the direction of adjustment with respect to the other cylinders.
The institution according to any one of claims 1 to 13. The institution according to claim 14, wherein the second threshold is lower than the first threshold. The institution according to any one of claims 7 to 15, one or more of the first to third predetermined maps, preferably based on the tests of the institution, or the same or equivalent. An institution that is determined by the institution's factory based on institutional testing and that at least one of the first to third predetermined maps preferably comprises an algorithm and / or table. The common torque signal corresponds to the average indicated cylinder pressure of all cylinders, and the cylinder individual torque signal corresponds to the average indicated cylinder pressure of a specific cylinder related to the cylinder individual torque signal, claims 1 to 16. Institutions listed in any of. The control unit includes a cylinder individual cylinder offset module for each cylinder, and the cylinder individual cylinder offset module has the common torque signal, the common peak pressure signal, for a specific cylinder associated with the cylinder individual cylinder offset module. The engine according to any one of claims 1 to 17, configured to offset one or more of the common compression pressure signals. The engine according to any one of claims 1 to 18, wherein the cylinder individual cylinder offset module is controlled manually or automatically. The engine according to any one of claims 1 to 19, wherein the control unit is configured to individually control the plurality of cylinders without considering the cylinder balance. The control unit is configured to continuously calculate the difference between the cylinder individual torque signal and the cylinder individual actual torque signal as an error value, and is configured to perform correction based on the proportional term and the integral term.
The control unit is configured to continuously calculate the difference between the cylinder individual peak pressure signal and the cylinder individual actual peak pressure signal as an error value, and is configured to perform correction based on the proportional term and the integral term. Being done
The control unit is configured to continuously calculate the difference between the cylinder individual compression pressure signal and the cylinder individual actual compression pressure signal as an error value, and is configured to perform correction based on the proportional term and the integral term. ,
organ. The engine according to any one of claims 1 to 21, wherein the fuel supply system is configured to supply a first fuel and / or a second fuel to the associated cylinder. A method of operating a crosshead type large low-speed turbocharged 2-stroke uniflow scavenging internal combustion engine (9).
An exhaust valve (4), an exhaust valve operating system (46) for operating the exhaust valve, a fuel supply system (30) for supplying the first fuel to the related cylinders, and a cylinder individual pressure signal indicating the pressure in the related cylinders. With a plurality of cylinders (1) each comprising a pressure sensor (42) to generate;
With an exhaust driven turbocharger (5) that pressurizes scavenging for the cylinder;
The above method comprises
For a particular cylinder of the plurality of cylinders, including controlling at least one combustion process parameter of the cylinder in a closed loop as a function of a cylinder individual compression signal and a cylinder individual setpoint.
Here, the cylinder individual setpoint is a cylinder individual offset from a common setpoint for all cylinders. The at least one combustion process parameter is
・ Fuel amount;
・ Fuel injection start timing;
・ Exhaust valve closing timing;
23. The method of claim 23, comprising one or more of the above. 23. The method of claim 23 or 24, wherein the closed loop control is performed without any consideration of maintaining cylinder balance. The method of any of claims 23-25, wherein the closed-loop control applies corrections based on proportional and integral terms. The common set point is
A common torque signal representing the torque to be produced by the engine and / or
A common peak pressure signal representing the peak cylinder pressure to be achieved in the cylinder and / or
A common compression pressure signal representing the compression pressure to be achieved in the cylinder,
The method according to any one of claims 22 to 26. The method according to any one of claims 23 to 27, wherein the closed loop control uses a cylinder pressure individually measured for each cylinder as a reference value. From the measured cylinder pressure, the cylinder individual average indicated cylinder pressure is derived and / or
Cylinder individual peak pressure is derived from the measured cylinder pressure and / or
The individual cylinder compression pressure is derived from the measured cylinder pressure.
28. The method of claim 28. A crosshead type large low-speed turbocharged 2-stroke uniflow scavenging internal combustion engine (9).
An exhaust valve (4), an exhaust valve operating system (46) for operating the exhaust valve, a fuel supply system (30) for supplying the first fuel to the related cylinders, and a cylinder individual pressure signal indicating the pressure in the related cylinders. With a plurality of cylinders (1) each comprising a pressure sensor (42) to generate;
With an exhaust driven turbocharger (5) that pressurizes scavenging for the cylinder;
With a control unit (55) configured to individually control at least one of the combustion process parameters, fuel amount, fuel injection start timing, and exhaust valve closing timing;
The control unit
By periodically adjusting a common setpoint for combustion process parameters or individual cylinder setpoints for each cylinder, the combustion process parameters for each of the plurality of cylinders can be set as a function of the operating conditions of the engine. Control individually,
Calculate the average of the individual cylinder adjustments of the combustion process parameters over multiple cylinders.
In one cycle of the combustion process parameters, the adjustment is limited to the calculated mean plus or minus default maximum deviation.
An institution that is structured so that. 30. The control unit defines the calculated mean plus or minus window of the defined maximum deviation, and is configured to limit the adjustment in one cycle to the adjustment within the window. The listed institution. 31. The institution of claim 31, wherein the window has a first range in the positive direction and a second range in the negative direction from the calculated average. 32. The engine of claim 32, wherein the window is dedicated to the combustion process parameters. The institution according to claim 32 or 33, wherein the positive range has a first predetermined magnitude and the negative range has a second predetermined magnitude. The control unit either calculates the average of the combustion process parameters for the individual cylinders over the plurality of cylinders in one cycle, or averages the combustion process parameters for the periodic adjustments over the plurality of cycles. The institution according to any of claims 30-34, which is configured to calculate. The engine according to any of claims 30-35, wherein the adjustment of the combustion process parameters is an adjustment for a single cycle. The at least one combustion process parameter is
・ Fuel amount;
・ Fuel injection start timing;
・ Exhaust valve closing timing;
The institution according to any one of claims 30 to 36, comprising one or more of the above. The engine of any of claims 30-37, wherein the cylinder-specific setpoints of the combustion process parameters are offsets from the common setpoints of the combustion process parameters. The operating conditions of the engine are one or more of engine speed, engine load, cylinder peak pressure, cylinder combustion pressure, cylinder average indicated pressure, scavenging pressure, fuel type, immediate humidity, environmental temperature. The institution according to any of 30 to 38. A method of operating a crosshead type large low-speed turbocharged 2-stroke uniflow scavenging internal combustion engine (9).
A plurality of cylinders (1) each including an exhaust valve (4), an exhaust valve operating system (46) for operating the exhaust valve, and a fuel supply system (30) for supplying a first fuel to the related cylinders;
With an exhaust driven turbocharger (5) that pressurizes scavenging for the cylinder;
The above method is:
Controlling at least one of the combustion process parameters, fuel amount, fuel injection start timing, and exhaust valve closing timing for each cylinder;
By periodically adjusting a common setpoint for combustion process parameters or individual cylinder setpoints for each cylinder, the combustion process parameters for each of the plurality of cylinders can be set as a function of the operating conditions of the engine. To control individually;
To calculate the average of the individual cylinder adjustments;
To define a window around the calculated average;
In one cycle of the combustion process parameters, limiting the adjustment to the calculated mean plus or minus default maximum deviation;
Including methods.

Images