KR20220015990A - Engine status estimation apparatus, engine status estimation method and engine status estimation program - Google Patents

Abstract

Provided is an engine status estimating apparatus capable of estimating an engine status with a stable precision level. The engine status estimating apparatus (100) for estimating the engine (200) status comprises: an air density measurement data acquisition unit (110) which acquires measurement data of parameters related to air density which the engine (200) sucks in and supplies to a combustion unit; and a status estimation unit (120) for estimating the engine (200) status based on the air density measurement data and a fuel supply amount U to the combustion unit input to an engine model indicating characteristics of the engine (200).

Description

Engine condition estimation apparatus, engine condition estimation method, and engine condition estimation program

The present invention relates to an engine state estimation technique.

Engines are widely used in ships, automobiles, aircraft, and the like, and there is also a heightened awareness of environmental problems, and in recent years, further high efficiency is required, and thus various technologies are being developed.

Japanese Patent Laid-Open No. 2005-307800 Japanese Patent Laid-Open No. 2015-222074 Japanese Patent Laid-Open No. 2015-3658

As an example, the simulation technique of the parameter of the engine disclosed by patent document 1 is known. Patent document 1 simulates the tuning frequency of the pressure wave in an intake pipe as a parameter of an engine using a predetermined|prescribed calculation model. However, there is a problem that the operation and state of the engine change every moment, and even if the simulation is performed using the same calculation model, there is a problem that the accuracy thereof fluctuates.

The present invention has been made in view of such a situation, and an object thereof is to provide an engine state estimating apparatus capable of estimating the state of the engine with stable precision.

In order to solve the above problems, an engine state estimating device of an aspect of the present invention is an engine having a combustion unit that generates power by burning air and fuel, and a supercharger that increases the pressure of inhaled air and supplies it to the combustion unit An engine state estimating device for estimating the state of: an air density measurement data acquisition unit configured to acquire measurement data of parameters related to the density of at least one of air sucked in by a supercharger and compressed air supplied to a combustion unit by the supercharger; and a state estimating unit for estimating the state of the engine based on the measurement data and the fuel supply amount to the combustion unit input to the engine model indicating the characteristics of the engine.

In this aspect, parameters relating to the density of at least one of the air sucked in by the supercharger and compressed air supplied to the combustion unit by increasing the pressure by the supercharger are measured, and the state of the engine is estimated using the parameters. This parameter represents the density of air used in combustion in the combustion section, and among many engine-related parameters, it has a particularly large influence on the operation or state of the engine. Therefore, when this parameter is fluctuated, the state of the engine is greatly fluctuated, and it becomes a factor in which the accuracy of state estimation is greatly varied. In the present invention, since the parameter having such a large influence on the engine state can be measured as air density measurement data and used for state estimation, the engine state can be estimated with stable accuracy.

Another aspect of the present invention is an engine state estimation method. This method is an engine state estimation method for estimating the state of an engine having a combustion unit that generates power by burning air and fuel, and a supercharger that increases the pressure of intake air and supplies it to the combustion unit, an air density measurement data acquisition step of acquiring measurement data of a parameter relating to the density of at least one of air and compressed air supplied to the combustion unit by the supercharger; the air density measurement data; and a state estimation step of estimating the state of the engine based on the fuel supply amount to the bureau.

In addition, any combination of the above components and conversion of the expression of the present invention between methods, apparatuses, systems, recording media, computer programs, and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to estimate the state of the engine with stable precision.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the engine state estimation apparatus which concerns on 1st Embodiment.
2 is a schematic diagram showing the configuration of a four-stroke engine.
3 is a schematic diagram showing the configuration of a two-stroke engine.
4 is a view showing the effect of air density measurement data on the output of the engine.
5 is a diagram illustrating an effect of air density measurement data on fuel efficiency of an engine.
6 is a view showing the effect of air density measurement data on the temperature of the gas flowing in the engine.
7 is a view showing the effect of air density measurement data on the pressure of the gas flowing in the engine.
8 is a schematic diagram showing the configuration of an engine state estimation device according to the second embodiment.

The engine state estimation apparatus of this embodiment estimates the state of an engine using the mathematical model which shows the characteristic of an engine. Among many engine-related parameters, by measuring the temperature and pressure of air for fuel combustion, which has a large influence on engine output and fuel efficiency, and using it for state estimation, estimation accuracy can be improved.

1 is a schematic diagram showing the configuration of an engine state estimation device 100 according to a first embodiment. The engine state estimating apparatus 100 is an apparatus for estimating the state of the engine 200 , and includes an air density measurement data acquisition unit 110 and a state estimating unit 120 .

Before explaining each part of the engine state estimation apparatus 100, the engine 200 which is the state estimation object is demonstrated with reference to FIG.2 and FIG.3.

2 is a schematic diagram showing a so-called four-stroke engine as an example of the engine 200 . As will be described later, a four-stroke engine is an engine in which one cycle consisting of four strokes of intake, compression, combustion, and exhaust is performed by four vertical movements of the piston (two times of raising and two times of descending).

The engine 200 includes a combustion unit 210 for generating power by mixing air and fuel, and a supercharger 240 for supplying the combustion unit 210 by increasing the pressure of the inhaled air. The supercharger 240 is a so-called turbocharger, and the turbine 242 rotates by the gas discharged after combustion in the combustion unit 210, and the turbine 242 and the turbine 242 by the shaft 243 are coupled coaxially and interlocked. A rotating compressor 241 is provided.

The compressor 241 has one end open to the outside air (atmosphere) and the other end provided on one end side in the air supply passage 220 that communicates with the combustion unit 210 , and simultaneously compresses the outside air by its rotation. Air compressed by the compressor 241 and having an increased pressure is supplied to the combustion unit 210 through the supply path 220 and used for combustion of fuel there. The air supply path 220 includes an intake pipe 221 through which air sucked in by the compressor 241 flows from one end open to the outside air, and an air supply pipe through which the compressed air supplied by the compressor 241 to the combustion unit 210 flows. 222 and an air supply receiver 223 as an air supply receiving unit provided at a position close to the combustion unit 210 on the other end side to receive compressed air. In addition, in order to prevent expansion due to the temperature rise of the air compressed by the compressor 241 , the supply air cooler 224 , which is a cooler that cools the compressed air flowing through the air supply pipe 222 , is installed in the middle of the air supply pipe 222 . is provided. Thereby, the temperature of the compressed air cooled while flowing through the supply air cooler 224 and accommodated in the air supply receiver 223 is maintained within a predetermined range.

The turbine 242 is provided on the other end side in the exhaust passage 230 in which one end communicates with the combustion unit 210 and the other end is open to outside air (atmosphere). The gas discharged after combustion in the combustion unit 210 rotates the turbine 242 with the momentum, and then is discharged from the other end of the exhaust path 230 to the outside air. The exhaust path 230 is provided at a position close to the combustion unit 210 at one end, and includes an exhaust receiver 231 serving as an exhaust receiving unit for receiving gas discharged after combustion in the combustion unit 210 , and an exhaust receiver 231 . ), the exhaust pipe 232 through which the exhaust gas toward the turbine 242 flows, and the turbine outlet pipe 233 through which exhaust gas from the other end after passing through the turbine 242 to the outside air flows through is provided.

The combustion unit 210 includes a combustion chamber 211 in which combustion of fuel by air occurs, and a fuel supply nozzle 212 for supplying fuel in an amount specified by the fuel supply amount U per combustion into the combustion chamber 211; An intake valve 213 for controlling the supply of air from the supply air receiver 223 to the combustion chamber 211 , an exhaust valve 214 for controlling the discharge of gas from the combustion chamber 211 to the exhaust receiver 231 , and the combustion chamber The piston 215 linearly driven according to the combustion of fuel in (211), the crankshaft 216 as a rotational drive part rotationally driven with linear motion of the piston 215, and one end of the piston ( The connecting rod 217 is fixed to 215 and the other end is fixed to the crankshaft 216 to convert the linear motion of the piston 215 into the rotational motion of the crankshaft 216 . In addition, in the above configuration, fuel is directly supplied into the combustion chamber 211 by the fuel supply nozzle 212, but when using a highly volatile fuel such as gasoline, the air supply receiver 223 or the air supply pipe 222 You may inject fuel inside and supply it in the combustion chamber 211 in the state mixed with air.

In the above configuration, the engine 200 is driven in the following cycle. Here, it is assumed that the engine 200 is in an operating state by driving before the previous cycle or driving by combustion of the multi-cylinder, and the piston 215 rises and falls according to the operation of the crankshaft 216 that continues to rotate. is to be repeated.

(1) Intake: The intake valve 213 is opened, the exhaust valve 214 is closed, and the piston 215 is lowered, whereby air is supplied from the supply air receiver 223 to the combustion chamber 211 .

(2) Compression: The intake valve 213 is closed and the piston 215 rises, whereby the air in the combustion chamber 211 is compressed.

(3) Combustion: A fuel in an amount specified by the fuel supply amount U per combustion is supplied into the combustion chamber 211 from the fuel supply nozzle 212 and is combusted in compressed air. As a result, power is generated and the piston 215 descends.

(4) Exhaust: The exhaust valve 214 is opened and the piston 215 rises, so that the gas after combustion is discharged from the combustion chamber 211 to the exhaust receiver 231 .

FIG. 3 is a schematic diagram showing a combustion unit of a so-called two-stroke engine as another example of the engine 200 (the same reference numerals are attached to the components corresponding to those of FIG. 2 and description thereof is omitted appropriately). In the two-stroke engine, unlike the four-stroke engine of FIG. 2 in which one cycle is completed by four up-and-down movements of the piston, one cycle is completed by a total of two vertical movements of one rising and one lowering of the piston.

The combustion unit 210 of the two-stroke engine linearly drives the piston 215 by combustion of the fuel in the combustion chamber 211, similarly to the above-described four-stroke engine, and causes it to rotate the crankshaft 216. transforming it into power. Although the main structures of both types of engines are almost common, in the two-stroke engine, in the combustion section 210 , the crankcase 218 accommodating the crankshaft 216 and the scavenging path 219 connecting the combustion chamber 211 are ) is one difference.

In the illustrated state in which the piston 215 is descending, the path passing through the crankcase 218, the scavenging path 219, the combustion chamber 211, and the exhaust path 230 allows gas to flow, While fresh air in the case 218 flows into the combustion chamber 211 through the scavenging path 219 , the gas after combustion is discharged to the exhaust path 230 with the momentum (scavenging air).

Subsequently, when the piston 215 rises, the scavenging path 219 and the exhaust path 230 are blocked, the combustion chamber 211 is sealed, and the pressure rises. And, by supplying fuel from the fuel supply nozzle 212 into the high-pressure combustion chamber 211 , combustion is induced, and power to lower the piston 215 again is generated. On the other hand, when the piston 215 rises, the crankcase 218 and the air supply passage 220 communicate with each other, and new air flows into the crankcase 218 from the air supply passage 220 . In this way, when the piston 215 is raised, combustion in the combustion chamber 211 and air supply to the crankcase 218 are performed simultaneously.

As described above, in the two-stroke engine, one cycle is completed with a total of two strokes of one lowering and one raising of the piston 215 . In such a two-stroke engine, when the supercharger 240 shown in Fig. 2 is used, air supply to the crankcase 218 when the piston 215 is raised and the combustion chamber 211 when the piston 215 is lowered. ) can increase the desired pressure in the furnace.

In addition, you may use the thing of the structure disclosed by patent document 2 as a two-stroke engine. In this two-stroke engine, in the state in which the piston 41 (symbol in Patent Document 2 (hereinafter the same)) is descending, similarly to the above description for Fig. 3, the scavenging air receiver ( 2), the crankcase 218 and the scavenging mechanism 17 corresponding to the scavenging path 219, the cylinder 1 corresponding to the combustion chamber 211, and the exhaust duct 6 corresponding to the exhaust path 230 pass through The path to which gas can flow is made possible, and while new air in the scavenging air receiver flows into the cylinder through the scavenging port, the scavenging operation of discharging the gas after combustion to the exhaust duct with the force is performed. In addition, if the supercharger 240 is used in such a configuration, the pressure of the scavenging air in the scavenging air receiver can be increased.

The present embodiment can be applied to the various types of engines 200 as described above, regardless of uses for ships, vehicles, aircraft, etc., but especially for marine engines with a rated rotation speed of 1000 rotations per minute or less. it is suitable In general, an engine for a ship is driven at a lower rated rotational speed as described above as compared with an engine for a vehicle. And especially in large ships, since it takes time until the power generated by the engine is reflected in the actual movement of the ship, accurate engine driving is required. Thus, in the engine for ships, the request of estimating the state of an engine with high precision and performing accurate driving is strong, and it is preferable to use the engine state estimation apparatus 100 of this embodiment.

In addition, as a ship, the engine 200 of this embodiment can be used for the thing of the structure currently disclosed by patent document 3, for example. That is, the engine 200 of this embodiment is used as the main engine (10: code|symbol (the same below) in patent document 3) which generates the propulsion force of a ship, and the power generated there is transmitted to the propeller 14 via a drive shaft. As a result, the propeller 14 rotates to generate the thrust of the ship.

In the engine 200 having the above configuration, the gas used for combustion of fuel flows through the following path. Outside air → intake pipe (221) → compressor (241) → air supply pipe (222) → supply air receiver (223) → combustion section (210) (combustion chamber (211)) → exhaust receiver (231) → exhaust pipe (232) → turbine ( 242)→Turbine outlet pipe (233)→Outside air.

In the present embodiment, a sensor for measuring a parameter related to the density of air, specifically, a parameter such as a pressure and a temperature, can be provided at each location of the gas flow path. As shown, the installation positions of the sensors are classified into the following three places from S0 to S2.

S0: in the intake pipe (221)

S1: in the air supply pipe (222)

S2: in the supply air receiver (223)

At the sensor installation position S0 in the intake pipe 221 , a sensor for measuring the pressure and temperature of the external air sucked by the compressor 241 can be installed. The sensor installation position S0 in the intake pipe 221 is preferably set a predetermined distance apart from the open end of the intake pipe 221 open to the outside air and the inlet of the compressor 241 in order to enable stable measurement. do. If it is too close to the open end to the outside air, the measurement data is easily affected by sudden changes in the outside air, and if it is too close to the inlet of the compressor 241, it is measured by the influence of the airflow generated by the rotating compressor 241. There is a possibility that the environment will not be stable.

At the sensor installation position S1 in the air supply pipe 222 , a sensor for measuring the pressure and temperature of the compressed air supplied to the combustion unit 210 by the compressor 241 increasing the pressure may be installed. Regarding the temperature, the temperature of the compressed air may be directly measured, or the cooling temperature by the supply air cooler 224 for cooling the compressed air, that is, the temperature of a refrigerant such as cooling water may be measured indirectly. In addition, when the cooling temperature by the supply air cooler 224 is constant and it can be considered that the temperature of the compressed air in the air supply pipe 222 is constant, the importance of measuring the temperature at the sensor installation position S1 is low, so the pressure It is preferable to measure

In addition, it is preferable to set the sensor installation position S1 in the air supply pipe 222 to a position spaced apart a predetermined distance from the outlet of the compressor 241 in order to enable stable measurement. More preferably, it is the rear end of the supply air cooler 224, and if the position is set after the compressed air is sufficiently cooled, more stable measurement is possible. In particular, when the cooling temperature by the supply air cooler 224 can be regarded as constant, the compressed air temperature can also be considered constant, so the state of the compressed air in the air supply pipe 222 can be determined by measuring only the pressure. can be detected with high precision.

A sensor for measuring the pressure and temperature of the compressed air supplied to the combustion unit 210 may be installed at the sensor installation position S2 in the air supply receiver 223 . Like the air supply pipe 222 described above, when the cooling temperature by the supply air cooler 224 is constant and it can be considered that the temperature of the compressed air in the air supply receiver 223 is constant, the temperature is set at the sensor installation position S2. Since the measurement is of low importance, it is desirable to measure the pressure.

In addition, the sensor installation position S2 in the supply air receiver 223 is spaced a predetermined distance from the inlet of the compressed air from the air supply pipe 222 and the outlet of the compressed air to the combustion unit 210 in order to enable stable measurement. position is preferable. Thereby, the influence of the anomalous airflow which may generate|occur|produce in these places is avoided, and stable measurement becomes possible. In addition, when the cooling temperature by the supply air cooler 224 can be considered to be constant, the temperature of the compressed air in the supply air receiver 223 can also be considered to be constant, so by measuring only the pressure, the supply air receiver 223 The condition of the compressed air inside can be grasped with high precision.

The parameters measurable at the three sensor installation positions S0 to S2 described above represent the density of air used in combustion in the combustion unit 210 , and as will be described later, the engine by the engine state estimating device 100 . (200) is used to estimate the state. Here, it is not necessary to install a sensor in all of the three sensor installation positions S0 to S2, and if a sensor is installed in at least one, the state of the engine 200 can be estimated. On the other hand, when a sensor is installed at a plurality of sensor installation positions among S0 to S2, or when a plurality of sensors of different types are installed at one sensor position, based on a plurality of measurement data obtained there, the engine 200 can improve the precision of state estimation of

Returning to FIG. 1, each part (air density measurement data acquisition part 110, state estimation part 120) of the engine state estimation apparatus 100 which performs state estimation of the engine 200 is demonstrated.

The air density measurement data acquisition unit 110 acquires various types of air density measurement data measured at sensor installation positions S0 to S2. Specifically, measurement data of external air sucked by the compressor 241 is acquired from the sensor installation position S0 (in the intake pipe 221 ), and the compressor 241 increases the pressure of the air supplied to the combustion unit 210 . Measurement data is acquired from sensor installation positions S1 (inside the air supply pipe 222) and S2 (inside the supply air receiver 223).

The state estimator 120 for estimating the state of the engine 200 includes a calculator 121 that calculates a state variable, which is a parameter related to the state of the engine 200 , based on an engine model indicating characteristics of the engine 200 . to provide The engine model of the calculation unit 121 is a mathematical model of various characteristics of the engine 200 such as thermal efficiency, power transmission efficiency, dynamic characteristics, supercharger efficiency, and disturbance effect, and 1 supplied to the combustion unit 210 is The calculation is performed using, as input data, the fuel supply amount U per combustion, measurement data Ne of the rotation speed of the crankshaft 216 that generates rotational power in the combustion unit 210 , and the like, and the estimated value of each state variable of the engine 200 . is output as the engine state estimation result. As will be described later, in the present embodiment, in addition to the fuel supply amount U and the rotation speed Ne, the air density measurement data acquired by the air density measurement data acquisition unit 110 is also input into the engine model, so that the state of the engine 200 with high accuracy. can be estimated. In addition, although various methods of constructing the engine model can be considered, as a simple example, it is an output with respect to the input fuel supply amount U, rotation speed Ne, air density measurement data, etc.

It can be configured as a table in which the estimated values of the respective state variables of the engine 200 are matched.

The state variables of the engine 200 that can be estimated by the state estimator 120 may include, for example, the following.

Parameters related to the operation of the combustion unit 210:

The number of rotations of the crankshaft 216 (the number of rotations Ne of the combustion unit 210)

Parameters relating to the operation of the supercharger 240:

・The number of revolutions of the compressor 241, the turbine 242, and the shaft 243 (the number of revolutions of the supercharger 240 Ntc)

In addition, in this embodiment, since rotation speed Ne is acquired as measurement data, it is not necessary to estimate by the state estimation part 120. As shown in FIG.

The following are the state variables of the engine 200 that the air density measurement data acquisition unit 110 can acquire as measurement data. In the present embodiment, it is not necessary to estimate the state variables obtained as measurement data in this way by the state estimating unit 120 .

Parameters related to the external air inhaled by the compressor 241 (measurable at S0 in the intake pipe 221):

·External air pressure (external air pressure Pa)

·Temperature of outside air (outside temperature Ta)

Parameters related to compressed air (supply air) supplied to the combustion unit 210 by increasing the pressure by the compressor 241 (measurable at S1 in the air supply pipe 222 and S2 in the supply air receiver 223):

·Supply air pressure (supply air pressure Pb/in a two-stroke engine that performs scavenging operation, it is also denoted as scavenging air pressure Ps)

·Supply air temperature (supply air temperature Tb/in a two-stroke engine that performs scavenging operation, it is also denoted as scavenging air temperature Ts)

The temperature of the cooling water of the supply air cooler 224 (cooling water temperature Tw)

In addition to the above, parameters related to the gas flowing through each part in the engine 200:

Flow rate in intake pipe 221, air supply pipe 222, and air supply receiver 223

· Pressure, temperature, flow rate in the exhaust receiver 231 , the exhaust pipe 232 , and the turbine outlet pipe 233 .

Various performances of the engine 200 that can be calculated as an engine model using each of the above parameters:

Performance related to the power generated by the engine 200 (torque, output, etc.)

Performance related to fuel consumption of engine 200 (fuel consumption per unit time (hereinafter abbreviated as fuel economy), fuel consumption rate per unit time and unit output, travel distance per unit capacity of fuel, etc.)

Although all of the above-described state variables can be measured by providing an appropriate sensor, in the actual engine 200, it is not realistic to measure all the state variables due to cost or installation constraints. Therefore, in the present embodiment, only the rotational speed Ne and the partial air density measurement data used for improvement of the estimation accuracy in the state estimating unit 120 are measured, and the other state variables are the state estimating unit 120 . is configured to calculate the estimated value.

In addition, the fuel supply amount U per combustion which is a drive input to the engine 200 is set based on the measurement data of the rotation speed Ne of the combustion part 210 . That is, when the target rotation speed of the combustion unit 210 is set to Ne0, the difference between the measured value Ne and the target value Ne0 is calculated, and the fuel supply U per combustion at which the difference becomes smaller is calculated in a predetermined table or algorithm. is set based on

Then, the technique of improving the state estimation precision using the air density measurement data discovered through experiment by this inventor is demonstrated. 4 to 7 show the results of experiments on the effect of the outdoor temperature Ta, the outdoor pressure Pa, and the cooling water temperature Tw, which are air density measurement data, on various state variables of the engine 200 . Specifically, Fig. 4 shows the effect on output, Fig. 5 shows the effect on fuel efficiency, and Fig. 6 shows the temperature near the outlet of the compressor 241 in the air supply pipe 222 (compressor outlet temperature Tc), the air supply receiver ( The effect on each of the scavenging air temperature Ts in 223 and the exhaust temperature Tex in the exhaust receiver 231, FIG. 7 shows the scavenging air pressure Ps in the supply air receiver 223, the exhaust pressure Pex in the exhaust receiver 231, and the turbine outlet pipe ( 233) shows the influence on each of the internal pressures (turbine outlet pressure P0). In each experiment, measurement is performed while changing the load of the engine 200, and in each figure, the load of the engine 200 is 50%, 75%, 85%, 100% of the maximum load in each case. The results are different.

In each figure, when the external temperature Ta, the external atmospheric pressure Pa, and the cooling water temperature Tw change within the variation ranges of the assumed environmental conditions, the ratio of the change in the target state variable in each figure is shown as a graph. For example, looking at the outdoor temperature Ta of FIG. 4 for the output, when the load is 100%, there is an effect of about -1.2%, which is compared to the output when the outdoor temperature Ta is the lower limit within the assumed range, the outdoor temperature Ta is It means that the output at the upper limit within the assumed range is reduced by about 1.2%. Similarly, looking at the outdoor temperature Ta of FIG. 5 for fuel economy, when the load is 50%, there is an influence of about 1.5%, which is compared to the fuel efficiency when the outdoor temperature Ta is the lower limit within the assumed range, compared to the fuel efficiency when the outdoor temperature Ta is within the assumed range It means that the fuel efficiency at the upper limit is increased by about 1.5%.

Of the above experimental results, according to FIGS. 4 and 5 related to the output and fuel efficiency, which are important indicators of the engine 200, among the three air density measurement data, it can be seen that the outside temperature Ta protrudes, which greatly affects the output and fuel efficiency. have. Therefore, by measuring the outdoor temperature Ta at the sensor installation position S0 and supplying it to the state estimator 120 through the air density measurement data acquisition unit 110, the state estimator 120 can estimate the output and fuel efficiency with high precision. have.

According to FIG. 6 regarding the temperature of the gas circulating in the engine 200 , the external temperature Ta has the greatest influence on the compressor outlet temperature Tc (then the cooling water temperature Tw), and the influence on the scavenging temperature Ts is the cooling water temperature Tw the most. It can be seen that the external temperature Ta has the largest effect on the exhaust temperature Tex (then the cooling water temperature Tw).

In addition, according to FIG. 7 regarding the pressure of the gas flowing in the engine 200 , the external temperature Ta has the greatest effect on the scavenging air pressure Ps (then the cooling water temperature Tw), and the influence on the exhaust pressure Pex is the external temperature Ta the most. It can be seen that the effect on the turbine outlet pressure P0 is large (then the cooling water temperature Tw), and the external air pressure Pa is the largest.

Therefore, the outside air temperature Ta (sensor installation position S0), outside air pressure Pa (sensor installation position S0), and the cooling water temperature Tw (sensor installation position S1) are respectively measured, and the state estimation unit ( By supplying to 120), the state estimating unit 120 can estimate with high precision the state variable having a large influence by each air density measurement data.

In addition, although the experiment was performed with respect to three air density measurement data above, the suggestion obtained here is applicable also to other air density measurement data as follows.

The influence on the output and fuel efficiency shown in FIGS. 4 and 5 was the maximum at the outdoor temperature Ta, which indicates that the state of the outside air directly affects the basic operation of the engine 200 , that is, the combustion of fuel in the combustion unit 210 and the generation of power. is thought to be due to the influence of That is, since the outdoor air is sucked into the compressor 241 and supplied to the combustion unit 210 , it is understood that the state of the outdoor air has a large effect on the output and fuel efficiency of the engine 200 .

Meanwhile, in FIGS. 4 and 5 , the influence of the external air pressure Pa, which is another parameter indicating the state of the external air, on the output and fuel efficiency is hardly seen. This is considered to be because the output and fuel efficiency are hardly affected within the range of the assumed fluctuation of the external atmospheric pressure Pa.

When the outside air as described above is sucked and compressed by the compressor 241 and enters the air supply pipe 222 and the air supply receiver 223, this time the pressure, the supply air pressure Pb to the scavenging air pressure Ps, is a major factor affecting the output and fuel efficiency. I think it will be a parameter. This is because, by the supply air cooler 224 provided in the middle of the supply pipe 222, the supply air temperature Tb to the small air temperature Ts are cooled within a certain range, so the density of the air supplied to the combustion unit 210 is mainly determined by pressure. to be. Accordingly, in the engine 200 provided with the supply air cooler 224 , the supply air pressure Pb to the scavenging air pressure Ps of the cooled air are measured as air density measurement data, and the state estimation unit is passed through the air density measurement data acquisition unit 110 . By supplying to 120 , the state estimating unit 120 can estimate the output and fuel efficiency with high precision. On the other hand, in the engine 200 in which the supply air cooler 224 is not provided, similarly to the outside temperature Ta, the supply air temperature Tb to the small air temperature Ts will continue to have a great influence on output and fuel efficiency. Fuel economy can be estimated with high precision.

Summarizing the above, it is preferable to use the following air density measurement data in order to improve the estimation accuracy of the power and fuel efficiency, which are important indicators of the engine 200 .

・Outside temperature Ta

·Supply air pressure Pb to small air pressure Ps

·Supply air temperature Tb to small air temperature Ts (when the supply air cooler 224 is not provided)

The above knowledge obtained from FIGS. 4 to 7 is information indicating the relationship between each air density measurement data and each state variable, and it is preferable to pre-build it in the engine model of the calculation unit 121 . According to such an engine model, according to each measured air density measurement data, calculation of each state variable can be performed with high precision in consideration of the degree of influence as shown in FIGS. 4 to 7 .

In addition, through FIGS. 4 to 7, when the load of the engine 200 is a low load such as 50% of the maximum load, the influence of each gas density measurement data on each state variable tends to occur greatly. Able to know. It is considered that this is because, when the engine 200 is operating at a low load, it is easy to be affected by various changes inside and outside the engine 200 . Accordingly, the state estimating unit 120 is configured to estimate the state of the engine 200 using the gas density measurement data when the engine 200 is operated under a low load, for example, when it is operated at 50% or less of the maximum load. it is preferable On the other hand, when operating at a high load in which the influence of the gas density measurement data is relatively small, for example, during operation at a load higher than 50% of the maximum load, state estimation may be performed without using the gas density measurement data, and state estimation may be performed. You may reduce the frequency of itself.

The engine state estimation result output by the engine state estimating apparatus 100 as described above may be used, for example, for the following purposes.

The engine state estimation result can be used for various control of the engine 200 . According to this embodiment, since the state estimation precision of the engine 200 can be improved, the precision of control can also be improved with it.

The engine state estimation result can be used for monitoring the engine 200 and diagnosing deterioration. An engine abnormality can be accurately identified and a prompt response can be performed.

8 is a schematic diagram showing the configuration of the engine state estimation device 100 according to the second embodiment. Only the configuration of the state estimating unit 120 is different from the engine state estimating device 100 according to the first embodiment shown in FIG. 1 . The state estimation unit 120 includes a calculation unit 121 and an engine model correction unit 122 .

The calculation unit 121 uses the fuel supply amount U and the rotation speed Ne as input data, based on the engine model indicating the characteristics of the engine 200 , calculates an estimated value of the state variable of the engine 200 , and estimates the engine state output as a result. In this embodiment, unlike 1st Embodiment, the air density measurement data is not input to the engine model of the calculation part 121, but is supplied to the engine model correction|amendment part 122 of a rear stage. Instead, the calculation unit 121 calculates air density estimation data, which is an estimated value of the gas density measurement data, among calculations based on the engine model described above. As described in the first embodiment, all measurement data affecting the air density, such as external air pressure Pa, external temperature Ta, supply air pressure Pb/scavenge pressure Ps, supply air temperature Tb/surge temperature Ts, and cooling water temperature Tw, are ), the calculation unit 121 may obtain gas estimation data from a normal calculation for obtaining an engine state estimation result.

The engine model correction unit 122 sends the calculation unit 121 so that the difference between the air density estimation data supplied from the calculation unit 121 and the air density measurement data supplied from the air density measurement data acquisition unit 110 becomes small. Calibrate the engine model in Here, when there is a difference between the air density estimation data, which is an estimated value, and the air density measurement data, which is an actual measured value, the engine model that is the basis for calculating the estimated value is separated from the characteristics of the actual engine 200, so the engine model information By correcting the engine model by the government 122 , it is intended to approximate the characteristics of the actual engine 200 . Ideally, when the difference between the air density estimation data and the air density measurement data is always zero, the engine model accurately represents the actual characteristics of the engine 200 . Since the engine model better reflects the characteristics of the actual engine 200 by such correction, the precision of engine state estimation can be improved. In particular, in the present embodiment, the engine model can be effectively corrected by using the air density measurement data having a large influence on each state variable such as the output of the engine 200 and the fuel economy.

As mentioned above, this invention was demonstrated based on embodiment. The embodiment is an illustration, and it is understood by those skilled in the art that various modifications are possible in the combination of each component or each processing process, and that such modifications are also within the scope of the present invention.

Although the temperature or pressure was exemplified as the air density measurement data in the embodiment, other parameters related to the density of the air may be measured. For example, the concentration, density, and component amount of the gas are mentioned.

In addition, the functional configuration of each device described in the embodiment can be realized by hardware resources or software resources, or by cooperation between hardware resources and software resources. As a hardware resource, a processor, ROM, RAM, or other LSI may be used. As a software resource, programs such as an operating system and an application may be used.

Among the embodiments disclosed in the present specification, those in which a plurality of functions are provided in a distributed manner may be provided by integrating some or all of the plurality of functions, and conversely, those in which a plurality of functions are integrated and provided are examples of the plurality of functions. Some or all of it may be arranged to be dispersed. Regardless of whether the functions are integrated or distributed, it may be configured so as to achieve the object of the invention.

100: engine state estimation device
110: air density measurement data acquisition unit
120: state estimator
121: calculator
122: engine model correction unit
200: engine
210: combustion unit
220: air supply
221: intake pipe
222: air supply pipe
223: supply air receiver
224: supply air cooler
230: exhaust path
231: exhaust receiver
232: exhaust pipe
233: turbine outlet pipe
240: supercharger
241: Compressor
242: turbine

Claims (14)

An engine state estimating device for estimating the state of an engine, comprising: a combustion unit that generates power by burning air and fuel; and a supercharger that increases the pressure of intake air and supplies it to the combustion unit,
an air density measurement data acquisition unit configured to acquire measurement data of parameters relating to the density of at least one of the air sucked in by the supercharger and compressed air supplied to the combustion unit by the supercharger;
a state estimator for estimating the state of the engine based on the air density measurement data and the amount of fuel supplied to the combustion unit input to the engine model representing the characteristics of the engine
provided, an engine state estimating device. According to claim 1,
The engine is an engine for ships having a rated rotation speed of 1000 rotations per minute or less,
engine condition estimation device. 3. The method of claim 1 or 2,
The state estimating unit for estimating the state of the engine by inputting the air density measurement data to the engine model,
engine condition estimation device. 3. The method of claim 1 or 2,
The state estimating unit,
a calculation unit for calculating air density estimation data that is an estimated value of the air density measurement data based on the engine model;
An engine model correction unit for correcting the engine model so that a difference between the air density estimation data and the air density measurement data is small
provided, an engine state estimating device. According to claim 1,
The measuring device of the air density measurement data is provided in the intake pipe through which the air sucked by the supercharger flows,
engine condition estimation device. According to claim 1,
The measuring device of the air density measurement data is provided in the air supply receiving unit for accommodating the compressed air,
engine condition estimation device. According to claim 1,
The air density measurement data is at least one measurement data of the temperature and pressure of the air and the compressed air sucked by the supercharger,
engine condition estimation device. 8. The method of claim 7,
The air density measurement data is measurement data of the temperature of the air sucked by the supercharger,
engine condition estimation device. 9. The method according to claim 7 or 8,
The engine includes a cooler for cooling the compressed air,
The air density measurement data is measurement data of the pressure of the compressed air cooled by the cooler,
engine condition estimation device. According to claim 1,
The engine includes a cooler for cooling the compressed air,
The air density measurement data is measurement data of the temperature of the cooling medium of the cooler,
engine condition estimation device. According to claim 1,
The state estimating unit estimating the state of the engine based on measurement data of a rotation speed of a rotational driving unit generating rotational power in the combustion unit,
engine condition estimation device. According to claim 1,
The state estimating unit estimates the state of the engine when the load of the engine is 50% or less of the maximum load,
engine condition estimation device. An engine state estimation method for estimating the state of an engine having a combustion unit that generates power by burning air and fuel, and a supercharger that increases the pressure of intake air and supplies it to the combustion unit,
an air density measurement data acquisition step of acquiring measurement data of parameters related to the density of at least one of the air sucked in by the supercharger and the compressed air supplied to the combustion unit by the supercharger;
a state estimation step of estimating the state of the engine based on the air density measurement data and the amount of fuel supplied to the combustion unit input to an engine model representing the characteristics of the engine;
provided, an engine state estimation method. It is an engine state estimation computer program stored in a recording medium for estimating the state of an engine having a combustion unit that generates power by burning air and fuel, and a supercharger that increases the pressure of intake air and supplies it to the combustion unit,
an air density measurement data acquisition step of acquiring measurement data of parameters related to the density of at least one of the air sucked in by the supercharger and the compressed air supplied to the combustion unit by the supercharger;
a state estimation step of estimating the state of the engine based on the air density measurement data and the amount of fuel supplied to the combustion unit input to an engine model representing the characteristics of the engine;
An engine state estimation computer program stored in a recording medium to be executed by a computer.

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