CN114060159A

CN114060159A - Engine characteristic estimation device, engine characteristic estimation method, and storage medium

Info

Publication number: CN114060159A
Application number: CN202110877971.4A
Authority: CN
Inventors: 川谷圣; 藤原真; 笹岛己喜朗; 福岛圭一郎
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2020-07-31
Filing date: 2021-07-30
Publication date: 2022-02-18
Also published as: JP2022026885A; KR20220015991A

Abstract

The invention provides an engine characteristic estimation device, an engine characteristic estimation method and a storage medium, which can effectively estimate the characteristic of an engine. An engine characteristic estimation device (100) is provided with: a gas measurement data acquisition unit (110) that acquires gas measurement data that is a measurement value of gas used for combustion of fuel in an engine (200); a calculation unit that calculates gas estimation data, which is an estimation value corresponding to the gas measurement data, based on an engine model representing the characteristics of the engine (200) and the fuel supply amount to the combustion unit; and an engine characteristic estimation unit (130) that estimates the characteristic of the engine (200) on the basis of a comparison between the gas measurement data and the gas estimation data.

Description

Engine characteristic estimation device, engine characteristic estimation method, and storage medium

Technical Field

The present invention relates to a technique for estimating characteristics of an engine.

Background

Engines are widely used in ships, automobiles, aircrafts, and the like, but awareness of environmental issues is also increasing, and further high efficiency is demanded in recent years, and various technologies have been developed for this purpose.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-307800

Patent document 2: japanese patent laid-open publication No. 2015-222074

Patent document 3: japanese patent laid-open publication No. 2015-3658

Disclosure of Invention

Problems to be solved by the invention

As an example of this, a technique for estimating parameters related to the operation and state of an engine as disclosed in patent document 1 is known. Patent document 1 estimates a tuned frequency of a pressure wave in an intake pipe as a parameter of an engine using a predetermined calculation model, and uses a measured value of an engine speed at this time. In this calculation, when the engine does not have a characteristic change such as aged deterioration, it is considered that the calculation model accurately expresses the characteristics of the engine, and therefore the parameters can be estimated with high accuracy.

On the other hand, when the engine has changed in characteristics, the influence thereof is related to both the calculation model and the measurement value as the input data to be input to the calculation model. That is, the calculation model deviates from the changed engine characteristic, and the engine rotation speed as the measurement value changes from the normal time under the influence of the characteristic change. Thus, in the case where there is a characteristic variation in the engine, the estimation accuracy of the parameter deteriorates. Further, even if only the estimated value of the parameter obtained as a result of the calculation is observed, an indication that the estimation accuracy is deteriorated cannot be obtained, and thus a change in the characteristic of the engine cannot be recognized.

The present invention has been made in view of such circumstances, and an object thereof is to provide an engine characteristic estimation device capable of effectively estimating the characteristic of an engine.

Means for solving the problems

In order to solve the above problem, an engine characteristic estimation device according to an aspect of the present invention estimates a characteristic of an engine, the engine including: a combustion unit that combusts air and fuel to generate power; a turbine rotated by gas discharged after combustion in the combustion section; and a compressor that rotates in conjunction with the turbine and compresses air supplied to the combustion section, the engine characteristic estimation device including: a gas measurement data acquisition unit that acquires gas measurement data that is a measurement value relating to at least one of air supplied to the combustion unit by the compressor, gas discharged after combustion in the combustion unit, and gas that has passed through the turbine; a calculation unit that calculates gas estimation data, which is an estimation value corresponding to the gas measurement data, based on an engine model indicating characteristics of the engine and a fuel supply amount to the combustion unit; and an engine characteristic estimation unit that estimates a characteristic of the engine based on a comparison of the gas measurement data and the gas estimation data.

In this aspect, the fuel supply amount used by the calculation unit for calculation is data that is not affected by changes in the characteristics of the engine due to aging degradation, changes in the external environment such as the intake air temperature, and the like, and therefore the gas estimation data that is the calculation result thereof is less susceptible to changes in the characteristics of the engine. In contrast, the gas measurement data acquired by the gas measurement data acquisition unit is data measured in an actual engine, and is therefore susceptible to changes in the characteristics of the engine. By comparing the gas estimation data that is less susceptible to the engine characteristic change and the gas measurement data that is more susceptible to the engine characteristic change, the engine characteristic estimation unit can estimate the engine characteristic even when there is an engine characteristic change. In particular, the gas measurement data of the present invention is a measurement value relating to a gas used for combustion in an engine, and is also susceptible to a change in the characteristics of the engine among a plurality of engine-related parameters. By using such gas measurement data, the characteristics of the engine can be effectively estimated.

Another embodiment of the present invention is an engine characteristic estimation method. The method estimates a characteristic of an engine, the engine including: a combustion unit that combusts air and fuel to generate power; a turbine rotated by gas discharged after combustion in the combustion section; and a compressor that rotates in conjunction with the turbine and compresses air supplied to the combustion section, the engine characteristic estimation method including: a gas measurement data acquisition step of acquiring gas measurement data, which is a measurement value relating to at least one of air supplied to the combustion unit by the compressor, gas discharged after combustion in the combustion unit, and gas having passed through the turbine; a calculation step of calculating gas estimation data, which is an estimation value corresponding to the gas measurement data, based on an engine model indicating characteristics of the engine and a fuel supply amount supplied to the combustion portion; and an engine characteristic estimation step of estimating a characteristic of the engine based on a comparison of the gas measurement data and the gas estimation data.

In addition, an arbitrary combination of the above-described constituent elements, and a mode in which the expression of the present invention is converted between a method, an apparatus, a system, a recording medium, a computer program, and the like are also effective as modes of the present invention.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the characteristics of the engine can be effectively estimated.

Drawings

Fig. 1 is a schematic diagram showing a configuration of an engine characteristic estimation device according to a first embodiment.

Fig. 2 is a schematic diagram showing the structure of a four-stroke engine.

Fig. 3 is a schematic diagram showing the structure of a two-stroke engine.

Fig. 4 is a graph showing the influence on the measured data of each gas when the thermal efficiency changes.

Fig. 5 is a graph showing the influence on the measured data of each gas when the compressor efficiency changes.

Fig. 6 is a graph showing the influence on the measured data of each gas when the turbine efficiency changes.

Fig. 7 is a schematic diagram showing the configuration of an engine characteristic estimation device according to a second embodiment.

Description of the reference numerals

100: an engine characteristic estimating device; 110: a gas measurement data acquisition unit; 120: a state estimation unit; 130: an engine characteristic estimating unit; 131: a difference operator; 132: a history recording unit; 133: an estimation unit; 134: a parameter adjusting part; 140: an air temperature data acquisition unit; 200: an engine; 210: a combustion section; 220: a gas supply path; 221: an air inlet pipe; 222: a gas supply pipe; 223: a gas supply receiver; 224: a gas supply cooler; 230: an air exhaust path; 231: an exhaust receiver; 232: an exhaust pipe; 233: a turbine outlet duct; 240: a supercharger; 241: a compressor; 242: a turbine.

Detailed Description

The engine characteristic estimation device of the present embodiment estimates engine characteristics such as thermal efficiency and supercharger efficiency using measurement data such as pressure and temperature of gas used for combustion of fuel in the engine. The estimation data corresponding to the measured data is calculated using a mathematical model representing the characteristics of the engine, and the estimation of the characteristics of the engine is performed by comparing the estimation data with the measured data. That is, when the estimated data matches the measured data, it is known that the actual engine characteristic matches the mathematical model, and when the estimated data does not match the measured data, it is known that the actual engine characteristic deviates from the mathematical model.

Fig. 1 is a schematic diagram showing the configuration of an engine characteristic estimation device 100 according to a first embodiment. The engine characteristic estimation device 100 is a device that estimates the characteristics of the engine 200, and includes a gas measurement data acquisition unit 110, a state estimation unit 120 as a calculation unit, an engine characteristic estimation unit 130, and an air temperature data acquisition unit 140.

Before describing each part of the engine characteristic estimation device 100, an engine 200 to be a characteristic estimation object will be described with reference to fig. 2 and 3.

Fig. 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 that performs a single cycle including four strokes of intake, compression, combustion, and exhaust by four vertical movements (two times of ascent and two times of descent) of a piston.

The engine 200 includes a combustion unit 210 that generates power by mixing air and fuel and combusting the air, and a supercharger 240 that increases the pressure of the air taken in and supplies the air to the combustion unit 210. The supercharger 240 is a so-called turbocharger, and includes a turbine 242 that is rotated by gas discharged after combustion in the combustion section 210, and a compressor 241 that is coaxially coupled to the turbine 242 via a shaft 243 to rotate in conjunction therewith.

The compressor 241 is provided at a position on one end side in the air supply passage 220 having one end open to the outside air (atmosphere) and the other end communicating with the combustion portion 210, and sucks in the outside air and compresses the sucked outside air by the rotation of the compressor 241. The air compressed by the compressor 241 and having a high pressure is supplied to the combustion unit 210 through the air supply path 220 so as to be used for combustion of the fuel therein. The gas supply path 220 includes: an intake pipe 221 through which air sucked from one end of the compressor 241, which is open to outside air, flows; an air supply pipe 222 through which compressed air supplied from the compressor 241 to the combustion unit 210 flows; and an air supply receiver 223 as an air supply receiving portion provided at a position close to the combustion portion 210 on the other end side and receiving compressed air. In order to prevent the air compressed by the compressor 241 from expanding due to a temperature rise, an intake air cooler 224, which is a cooler for cooling the compressed air flowing through the air supply pipe 222, is provided in the middle of the air supply pipe 222. Thereby, the temperature of the compressed air cooled while flowing through the air-supply cooler 224 and stored in the air-supply receiver 223 is kept within a fixed range.

The turbine 242 is provided at a position on the other end side in the exhaust passage 230, one end of which communicates with the combustion section 210 and the other end of which is open to the outside air (atmosphere). The gas discharged after combustion in the combustion section 210 rotates the turbine 242 due to its potential, and is then discharged to the outside air from the other end of the exhaust passage 230. The exhaust path 230 includes: an exhaust receiver 231 as an exhaust housing portion, which is provided at a position close to the combustion portion 210 on one end side, and which houses gas discharged after combustion in the combustion portion 210; an exhaust pipe 232 through which exhaust gas flows from the exhaust receiver 231 toward the turbine 242; and a turbine outlet pipe 233 for circulating the exhaust gas after passing through the turbine 242 from the other end thereof until being discharged into the outside air.

The combustion unit 210 includes: a combustion chamber 211 for combustion of fuel caused by air to occur; a fuel supply nozzle 212 for supplying fuel of a quantity specified by a fuel supply quantity U per one combustion into the combustion chamber 211; an intake valve 213 for controlling the supply of air from the air supply receiver 223 to the combustion chamber 211; an exhaust valve 214 for controlling the discharge of gas from the combustion chamber 211 to an exhaust receiver 231; a piston 215 linearly driven in correspondence with combustion of fuel in the combustion chamber 211; a crankshaft 216 serving as a rotation driving unit that is driven to rotate in accordance with the linear motion of the piston 215; and a connecting rod 217 having one end fixed to the piston 215 and the other end fixed to the crankshaft 216, for converting the linear motion of the piston 215 into the rotational motion of the crankshaft 216. Further, although the fuel is directly supplied into the combustion chamber 211 through the fuel supply nozzle 212 in the above description, when fuel having high volatility such as gasoline is used, the fuel may be injected into the air supply receiver 223 or the air supply pipe 222 and supplied into the combustion chamber 211 in a state of being 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 multiple cylinders, and the piston 215 repeatedly ascends and descends in accordance with the operation of the crankshaft 216 that continues to rotate.

(1) Air intake: intake valve 213 is opened, exhaust valve 214 is closed, and piston 215 is lowered, thereby supplying air from air supply receiver 223 to combustion chamber 211.

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

(3) And (3) combustion: the fuel supply amount U per one combustion is supplied from the fuel supply nozzle 212 into the combustion chamber 211, and the fuel is combusted in the compressed air. Thereby generating power and lowering the piston 215.

(4) Exhausting: exhaust valve 214 opens and piston 215 moves upward, thereby discharging combusted gas from combustion chamber 211 to 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 (components corresponding to those in fig. 2 are given the same reference numerals and description thereof is omitted as appropriate). Unlike the four-stroke engine of fig. 2, which completes one cycle with four upward and downward movements of the piston, in the two-stroke engine, one cycle is completed by a total of two upward and downward movements by one upward and one downward movements of the piston.

Like the four-stroke engine described above, the combustion unit 210 of the two-stroke engine linearly drives the piston 215 by combustion of fuel in the combustion chamber 211, and converts the drive into rotational power of the crankshaft 216. In both types of engines, the main construction is almost the same, but there is a difference in the two-stroke engine: the combustion section 210 is provided with a scavenging passage 219 for connecting a crankcase 218 accommodating the crankshaft 216 and the combustion chamber 211.

In the illustrated state in which the piston 215 is lowered, gas can flow through a path passing through the crankcase 218, the scavenging passage 219, the combustion chamber 211, and the exhaust passage 230, and fresh air in the crankcase 218 flows into the combustion chamber 211 through the scavenging passage 219, and the combusted gas is discharged (scavenged) to the exhaust passage 230 by the momentum thereof.

When the piston 215 moves up, the scavenging passage 219 and the exhaust passage 230 are closed, and the combustion chamber 211 is sealed and the pressure thereof increases. Then, fuel is supplied from the fuel supply nozzle 212 into the combustion chamber 211 having a high pressure to cause combustion, and power for lowering the piston 215 again is generated. On the other hand, when the piston 215 moves up, the crankcase 218 communicates with the air supply passage 220, and fresh air flows into the crankcase 218 from the air supply passage 220. As described above, when the piston 215 moves upward, 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 by two strokes of one descent and one ascent of the piston 215. In such a two-stroke engine, when the supercharger 240 shown in fig. 2 is used, the pressure of the intake air to the crankcase 218 when the piston 215 is raised and the pressure of the scavenging air to the combustion chamber 211 when the piston 215 is lowered can be increased.

Further, as the two-stroke engine, a configuration as disclosed in patent document 2 may be used. In this two-stroke engine, similarly to the above description regarding fig. 3, in a state where the piston (41: reference numeral (the same shall apply hereinafter) in patent document 2) is lowered, gas can flow through a path passing through the scavenging receiver (2) corresponding to the intake receiver 223, the scavenging port (17) corresponding to the crankcase 218 and the scavenging passage 219, the cylinder (1) corresponding to the combustion chamber 211, and the exhaust duct (6) corresponding to the exhaust passage 230, and fresh air in the scavenging receiver flows into the cylinder through the scavenging port, and a scavenging operation of discharging the burned gas to the exhaust duct is performed by the momentum thereof. In addition, when the supercharger 240 is used in such a structure, the pressure of scavenging in the scavenging receiver can be increased.

The present embodiment is applicable to various types of engines 200 as described above, but is particularly suitable for use in marine engines having a rated rotation speed of 1000 rpm or less, without being limited to marine, vehicle, aircraft, and other applications. In general, a marine engine can be driven at a lower rated rotation speed than a vehicle engine as described above. In particular, in a large ship, since it takes time until power generated by the engine is reflected in an actual operation of the ship, accurate engine driving is required. As described above, in the marine engine, it is highly required to estimate the engine characteristics with high accuracy and to perform accurate driving, and it is preferable to use the engine characteristic estimation device 100 of the present embodiment.

Further, as a ship, the engine 200 of the present embodiment can be used in addition to the structure disclosed in patent document 3, for example. That is, the engine 200 of the present embodiment is used as a main power unit (10: reference numeral in patent document 3 (the same applies hereinafter)) for generating the propulsive force of the ship, and the power generated therein is transmitted to the propeller (14) via the drive shaft, whereby the propeller (14) is rotated to generate the propulsive force of the ship.

Here, the following characteristics are exemplified as the characteristics of the engine 200 estimated by the engine characteristic estimation device 100.

Thermal efficiency: efficiency of combustion in the combustion chamber 211. Also known as combustion efficiency.

Power transmission efficiency: the ratio of the effective torque after subtracting the loss at each mechanical portion with respect to the torque generated by the combustion portion 210. Also known as mechanical transmission efficiency.

Dynamic characteristics: the relationship between the parameters takes time into account. Responsiveness of pressure to temperature changes, etc.

Efficiency of the supercharger 240: the efficiency of the compressor 241, the efficiency of the turbine 242, etc.

Interference effects: the temperature (atmospheric temperature) and pressure (atmospheric pressure) of the outside air taken in by the engine 200, load fluctuations in the marine engine caused by the amount of water flowing into the propeller to be driven, and the like.

The disturbance is an important disturbance that has a large influence on the actual operation of engine 200, and can be treated in the same way as other characteristics in the characteristic estimation process of engine characteristic estimation device 100 of the present embodiment.

In the engine 200 configured as described above, the gas used for combustion of the fuel flows through the following path. External air → an intake duct 221 → a compressor 241 → an intake duct 222 → an intake air receiver 223 → a combustion portion 210 (combustion chamber 211) → an exhaust air receiver 231 → an exhaust duct 232 → a turbine 242 → a turbine outlet duct 233 → external air.

In the present embodiment, sensors for measuring parameters such as pressure, temperature, and flow rate of the gas may be provided at various positions in the gas flow path. As shown in the drawing, the installation positions of the sensors are classified into six positions S0 to S5 below.

S0: in the air inlet pipe 221

S1: in the gas supply pipe 222

S2: in the air supply receiver 223

S3: in the exhaust receiver 231

S4: in the exhaust pipe 232

S5: in the turbine outlet pipe 233

Sensors for measuring the pressure, temperature, and flow rate of the outside air sucked by the compressor 241 may be provided at a sensor installation position S0 in the intake pipe 221. In the present embodiment, an air temperature sensor for measuring the temperature of the outside air as shown in fig. 1 is provided at S0, and the air temperature data is supplied to the air temperature data acquisition unit 140 in the engine characteristic estimation device 100. The sensor installation position S0 in the intake pipe 221 is preferably a position spaced apart from the open end of the intake pipe 221 that opens to the outside air and the inlet of the compressor 241 by a predetermined distance, so that stable measurement can be performed. When the open end opened to the outside air is excessively close, the measurement data is easily influenced by a sudden change in the outside air, and when the open end is excessively close to the inlet of the compressor 241, there is a possibility that the measurement environment is unstable due to the influence of the airflow generated by the rotating compressor 241.

Sensors for measuring the pressure, temperature, and flow rate of the compressed air supplied from the compressor 241 to the combustion unit 210 may be provided at a sensor installation position S1 in the air supply pipe 222. As described above, since the supply air cooler 224 for cooling the compressed air is provided in the middle of the supply air pipe 222, the temperature of the compressed air in the portion near the supply air receiver 223 is kept within a fixed range. In this manner, in the present embodiment in which the supply air cooler 224 is provided, the temperature of the compressed air in the air supply pipe 222 does not greatly vary, and therefore the importance of measuring the temperature at the sensor installation position S1 is low. Therefore, in the case where the sensor is provided at the sensor installation position S1, it is preferable to measure the pressure or the flow rate. On the other hand, in the case where the charge air cooler 224 is not provided, the importance of measuring the temperature at the sensor installation position S1 becomes high.

The sensor installation position S1 in the air supply pipe 222 is preferably a position away from the outlet of the compressor 241 by a predetermined distance, so that stable measurement can be performed. More preferably, the compressed air at the subsequent stage of the charge air cooler 224 is cooled sufficiently to have a temperature within a fixed range. Thus, the temperature of the compressed air can be regarded as being almost constant, and therefore the state of the compressed air in the air supply pipe 222 can be accurately grasped based on the measurement data of the pressure or the flow rate.

Sensors for measuring the pressure, temperature, and flow rate of the compressed air supplied to the combustion unit 210 can be provided at the sensor installation position S2 in the air supply receiver 223. As with the air supply duct 222 described above, the supply air cooler 224 maintains the temperature of the compressed air in the supply air receiver 223 within a fixed range, and therefore the importance of measuring the temperature at the sensor installation position S2 is low. Therefore, in the case where the sensor is provided at the sensor installation position S2, it is preferable to measure the pressure or the flow rate. On the other hand, in the case where the charge air cooler 224 is not provided, the importance of measuring the temperature at the sensor installation position S2 becomes high.

It is preferable that the sensor installation position S2 in the air supply receiver 223 is a position spaced apart 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 by a predetermined distance, so that stable measurement can be performed. This makes it possible to perform stable measurement while avoiding the influence of abnormal air flow that may occur at these locations. Further, since the temperature of the compressed air in the supply air receiver 223 can be regarded as being almost constant by the supply air cooler 224, the state of the compressed air in the supply air receiver 223 can be accurately grasped based on the measurement data of the pressure or the flow rate.

Sensors for measuring the pressure, temperature, and flow rate of the gas discharged after combustion in the combustion unit 210 can be provided at the sensor installation position S3 in the exhaust receiver 231. The sensor installation position S3 in the exhaust receiver 231 is preferably set to a position a predetermined distance away from the inlet of the exhaust gas from the combustion unit 210 and the outlet of the exhaust gas to the exhaust pipe 232, so that stable measurement can be performed. This makes it possible to perform stable measurement while avoiding the influence of abnormal air flow that may occur at these locations.

A sensor for measuring the pressure, temperature, and flow rate of the exhaust gas flowing from the exhaust receiver 231 to the turbine 242 can be provided at a sensor installation position S4 in the exhaust pipe 232. The sensor installation position S4 in the exhaust pipe 232 is preferably set to a position apart from the inlet of the exhaust gas from the exhaust gas receiver 231 and the inlet of the turbine 242 by a predetermined distance, so that stable measurement can be performed. This makes it possible to perform stable measurement while avoiding the influence of abnormal air flow that may occur at these locations.

A sensor for measuring the pressure, temperature, and flow rate of the gas passing through the turbine 242 can be provided at a sensor installation position S5 in the turbine outlet pipe 233. The sensor installation position S5 in the turbine outlet pipe 233 is preferably set to a position spaced apart from the outlet of the turbine 242 and the open end of the turbine outlet pipe 233 that opens to the outside air by a predetermined distance, so that stable measurement can be performed. When the distance is too close to the outlet of the turbine 242, the measurement environment may be unstable due to the influence of the airflow generated by the rotating turbine 242, and when the distance is too close to the open end opened to the outside air, the measurement data is easily influenced by the sudden change of the outside air.

In the case where the sensor is provided at the sensor installation position S5 in the turbine outlet pipe 233, the temperature is preferably measured. As will be described later, the measurement data at S5 is data used for estimating the characteristics of engine 200, and is preferably data reflecting the characteristics and state of engine 200. Here, since one end of the turbine outlet pipe 233 is open to the outside air, even if the sensor is disposed at a position away from the open position, the sensor is slightly affected by the outside air. In particular, since the pressure changes due to the influence of the external air pressure, it is difficult to obtain an indication of the characteristics and state of the engine 200 even when the pressure is measured. In addition, since the density also changes when the pressure changes, it is also difficult to accurately measure the flow rate. Therefore, it is preferable to measure a temperature which is not easily affected by the outside air.

Of the six sensor installation positions described above, the sensor installation position S0 in the intake pipe 221 is used for measurement of the outside air, and the other five sensor installation positions S1 to S5 are used for measurement of the gas flowing through the engine 200. As will be described later, the gas measurement data obtained at S1 to S5 is used to estimate the characteristics of engine 200, and the outside air measurement data obtained at S0 is used to reduce the influence of disturbance from the outside air when estimating the characteristics of engine 200.

Here, the characteristics of the engine 200 can be estimated by providing a sensor at least one sensor installation position without providing a sensor at each of the five sensor installation positions S1 to S5. On the other hand, when sensors are provided at a plurality of sensor installation positions in S1 to S5, or when a plurality of sensors of different types are provided at one sensor position, the accuracy of the characteristic estimation of engine 200 can be improved based on the plurality of gas measurement data obtained thereby. Further, since components other than air are mixed into the exhaust gas after combustion in the combustion portion 210 to have high temperature and high pressure, the measurement environment is more severe than the intake side and the scavenging side. Therefore, it is preferable to provide sensors at the sensor providing positions S1, S2 on the air supply side/purge side.

Referring back to fig. 1, the respective units (the gas measurement data acquisition unit 110, the state estimation unit 120, the engine characteristic estimation unit 130, and the air temperature data acquisition unit 140) of the engine characteristic estimation device 100 that estimates the characteristic of the engine 200 will be described.

The gas measurement data acquisition unit 110 acquires various gas measurement data measured at the sensor installation positions S1 to S5. Specifically, measurement data of air supplied from the compressor 241 to the combustion section 210 is acquired from the sensor installation positions S1 (in the air supply pipe 222) and S2 (in the air supply receiver 223), measurement data of gas discharged after combustion in the combustion section 210 is acquired from the sensor installation positions S3 (in the exhaust receiver 231) and S4 (in the exhaust pipe 232), and measurement data of gas passing through the turbine 242 is acquired from the sensor installation position S5 (in the turbine outlet pipe 233).

The state estimating unit 120 calculates a parameter relating to the state of the engine 200 based on an engine model indicating the characteristics of the engine 200, the fuel supply amount U per combustion supplied to the combustion unit 210, and measurement data Ne of the rotation speed of the crankshaft 216 that generates rotational power in the combustion unit 210. The engine model mathematically models the characteristics of the engine 200 such as the thermal efficiency, the power transmission efficiency, the dynamic characteristics, the supercharger efficiency, the influence of disturbance, and the like exemplified above, calculates the fuel supply amount U and the rotation speed Ne as input data, and outputs the estimated values of the state variables of the engine 200 as the engine state estimation results. Since the parameters of the gas measurement data acquired by the gas measurement data acquisition unit 110 are all state variables of the engine 200, the state estimation unit 120 can calculate gas estimation data, which is an estimation value corresponding to the gas measurement data, among the above calculations using the fuel supply amount U and the rotation speed Ne as inputs to the engine model. Further, various methods of constructing the engine model are considered, and as a simple example, the engine model can be constructed as a table in which the fuel supply amount U, the rotation speed Ne, and the like as inputs are associated with estimated values of the respective state variables of the engine 200 as outputs.

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

Parameters related to the operation of the combustion unit 210:

rotational speed of crankshaft 216 (rotational speed Ne of combustion unit 210)

Parameters related to the operation of the supercharger 240:

rotational speeds of compressor 241, turbine 242, and shaft 243 (rotational speed Ntc of supercharger 240)

In the present embodiment, since the rotation speed Ne is acquired as measurement data, it is not necessary to estimate the rotation speed Ne by the state estimating unit 120.

The following are variables that the gas measurement data acquisition unit 110 can acquire as gas measurement data, among the state variables of the engine 200.

Parameters related to compressed air (supply air) supplied from the compressor 241 to the combustion section 210 (which can be measured at S1 in the air supply pipe 222 and S2 in the air supply receiver 223):

pressure of intake air (intake air pressure Pb/scavenging pressure Ps in the case of a two-stroke engine performing a scavenging operation)

Temperature of intake air (intake air temperature Tb/scavenging temperature Ts in the case of a two-stroke engine performing a scavenging operation)

Flow rate of intake air (intake air amount Gb/scavenging amount Gs in the case of a two-stroke engine performing a scavenging operation)

Parameters relating to the gas (exhaust gas) discharged after combustion in the combustion unit 210 (which can be measured at S3 in the exhaust receiver 231 and S4 in the exhaust pipe 232):

pressure of exhaust (exhaust pressure Pex)

Temperature of exhaust gas (exhaust temperature Tex)

Flow rate of exhaust gas (exhaust gas quantity Gex)

Parameters relating to the gas after passing through the turbine 242 (which can be measured at S5 within the turbine exit duct 233):

pressure in the turbine outlet pipe 233 (turbine outlet pressure P0)

Temperature in the turbine outlet pipe 233 (turbine outlet temperature T0)

Flow in the turbine outlet pipe 233 (turbine outlet flow G0)

Various performances of the engine 200 that can be calculated by the engine model using the above-mentioned parameters:

performance (torque, output, etc.) relating to the power generated by the engine 200

Performances related to fuel consumption of engine 200 (fuel consumption per unit time, fuel consumption rate per unit time and output, travel distance per unit volume of fuel, etc.)

Each of the above state variables can be measured by providing an appropriate sensor, but in the actual engine 200, it is not practical to measure all the state variables due to limitations in cost and installation. Therefore, in the present embodiment, the following configuration is adopted: only the measurement data of the rotation speed Ne is supplied to the state estimating unit 120, and the state estimating unit 120 calculates the estimated values of the state variables other than the rotation speed Ne. In the present embodiment, a part of the parameters relating to the gas used in the engine characteristic estimating unit 130 as described above are also measured at S1 to S5.

Further, fuel supply amount U per one combustion as a drive input to engine 200 is set based on measurement data of rotation speed Ne of combustion unit 210. That is, assuming that Ne0 is the target rotation speed of combustion unit 210, the difference between Ne as the measurement value and Ne0 as the target value is calculated, and fuel supply amount U per combustion is set such that the difference is small, based on a predetermined table or algorithm.

The engine characteristic estimating unit 130 estimates the characteristic of the engine 200 based on a comparison between the gas measurement data supplied from the gas measurement data acquiring unit 110 and the gas estimation data supplied from the state estimating unit 120. The characteristics of the engine 200, such as the thermal efficiency, the power transmission efficiency, the dynamic characteristics, the supercharger efficiency (compressor efficiency/turbine efficiency), and the influence of disturbance, which have been exemplified above, are incorporated into the engine model of the state estimating unit 120, but may change due to the change in external environment, such as deterioration with age or the intake air temperature, and therefore it is necessary to estimate the latest characteristics by the engine characteristic estimating unit 130.

The engine characteristic estimating unit 130 includes: a difference calculator 131 that calculates a difference between the gas measurement data and the gas estimation data; a history recording unit 132 that records history data of the difference calculation result of the difference calculator 131; and an estimation unit 133 that estimates the characteristics of the engine 200 based on the difference calculation result of the difference calculator 131 and the history data of the history recording unit 132.

Engine characteristic estimating unit 130 estimates the characteristic of engine 200 as follows. The engine characteristic estimating unit 130 acquires data corresponding to both the gas measurement data from the gas measurement data acquiring unit 110 and the gas estimation data from the state estimating unit 120. When the scavenging pressure Ps is taken as an example for explanation, the gas measurement data acquisition unit 110 provides an actual measurement value of the scavenging pressure Ps measured at S1 or S2, and the state estimation unit 120 provides an estimation value of the scavenging pressure Ps. Here, when the actual characteristic of the engine 200 matches the characteristic mathematically modeled by the state estimating unit 120, the estimated value of the scavenging pressure Ps calculated by the state estimating unit 120 matches the actual measured value of the scavenging pressure Ps from the gas measurement data acquiring unit 110. Therefore, the output of the difference calculator 131 at this time is zero, and the estimation unit 133 can estimate the characteristic mathematically modeled by the state estimation unit 120 as the actual characteristic of the engine 200.

On the other hand, when the actual characteristic of the engine 200 deviates from the characteristic mathematically modeled by the state estimating unit 120, the estimated value of the scavenging pressure Ps calculated by the state estimating unit 120 does not match the actual measurement value of the scavenging pressure Ps from the gas measurement data acquiring unit 110. Therefore, the output of the difference calculator 131 at this time is not zero, and the estimation unit 133 can recognize that the characteristic mathematically modeled by the state estimation unit 120 is deviated from the actual characteristic of the engine 200. The absolute value and sign of the difference calculation result of the difference calculator 131 indicate the degree of deviation of the characteristic, and the estimation unit 133 can estimate the actual characteristic of the engine 200 based on this. Here, the estimation unit 133 can estimate that the characteristic of the engine 200 has changed when a temporary change in the difference calculation result due to an unexpected abnormality is ignored and a fixed difference is present for a certain period of time by referring to the history data recorded in the history recording unit 132 in addition to the instantaneous value from the difference calculator 131.

Various methods of estimating the characteristics of the engine 200 based on the result of the difference operation between the gas measurement data and the gas estimation data as described above can be conceived, but for example, a conversion table for converting the result of the difference operation into an estimated value of the characteristics may be stored in the estimation unit 133 in advance. As a simplest example, when the characteristics of one engine 200 (for example, the thermal efficiency of the combustion unit 210) are estimated based on the result of the difference calculation between a set of the gas measurement data and the gas estimation data (for example, the set of the actual measurement value and the estimation value of the scavenging pressure Ps), a conversion table in which the estimation value of the thermal efficiency and the possible value of the result of the difference calculation of the scavenging pressure Ps are associated one by one may be prepared in advance. In practice, there may be cases where a plurality of characteristics of the engine 200 (for example, the thermal efficiency of the combustion unit 210 and the efficiency of the compressor 241) are estimated based on the results of difference calculation between a plurality of sets of gas measurement data and gas estimation data (for example, a set of actual measurement values and estimation values of the scavenging pressure Ps and the turbine outlet temperature T0), but a plurality of conversion tables obtained by associating a plurality of difference calculation results with a plurality of characteristic estimation values may be prepared in advance based on the same consideration as described above.

Further, instead of preparing a fixed conversion table as described above, the estimation unit 133 may be configured to automatically update the estimation method using a machine learning technique. In this case, it is also preferable to provide the conversion table as described above as a reference, and the estimation unit 133 can estimate the characteristics of the engine 200 with high accuracy while appropriately updating the conversion table in view of the result of the machine learning.

Next, the relationship between various gas measurement data that can be measured at the sensor installation positions S1 to S5 and various characteristics of the engine 200 that can be estimated based on the gas measurement data will be specifically described.

First, as described above by way of example, the following gas measurement data can be measured at the sensor installation positions S1 to S5.

Supply pressure Pb/scavenging pressure Ps

Supply temperature Tb/scavenging temperature Ts

Gb air supply/Gs scavenging

Exhaust pressure Pex

Exhaust temperature Tex

Displacement Gex

Turbine outlet pressure P0

Turbine outlet temperature T0

Turbine outlet flow G0

In addition, characteristics of engine 200 that can be estimated are exemplified below.

Thermal efficiency

Efficiency of power transmission

Dynamic characteristics

Supercharger efficiency (compressor efficiency/turbine efficiency)

Interference effects

The gas measurement data listed above is a measurement value relating to a gas used for combustion of fuel in the engine 200, and is affected by changes in the characteristics of the engine 200 listed above. Therefore, basically, the engine characteristics can be estimated based on the gas measurement data in any combination of the above-listed gas measurement data and the above-listed engine characteristics.

The inventors have further discussed and determined the following gas measurement data suitable for making estimates of thermal efficiency and supercharger efficiency.

Gas measurement data suitable for estimation of thermal efficiency are as follows.

Supply pressure Pb/scavenging pressure Ps

Gb air supply/Gs scavenging

Exhaust pressure Pex

Displacement Gex

Gas measurement data suitable for performing estimation of supercharger efficiency are as follows.

Supply pressure Pb/scavenging pressure Ps

Supply temperature Tb/scavenging temperature Ts

Gb air supply/Gs scavenging

Exhaust pressure Pex

Exhaust temperature Tex

Displacement Gex

Turbine outlet temperature T0

Fig. 4 to 6 show the results of experiments performed by the present inventors to determine the above gas measurement data. Fig. 4 shows the influence on the measured data of each gas when the thermal efficiency changes, fig. 5 shows the influence on the measured data of each gas when the compressor efficiency changes, and fig. 6 shows the influence on the measured data of each gas when the turbine efficiency changes. In each experiment, the load of the engine 200 was measured while varying, and the results of the cases where the load of the engine 200 was 50%, 75%, 85%, and 100% of the maximum load are shown in the respective drawings.

In each drawing, a graph is shown as a ratio of a change in value of each gas measurement data when a target engine characteristic changes within a range of variation of an assumed environmental condition. For example, from the scavenging pressure Ps of fig. 4, there is an influence of about 10% at the load of 85%, which means that the scavenging pressure Ps at the time when the thermal efficiency is the upper limit in the assumed range becomes larger by about 10% with respect to the scavenging pressure Ps at the time when the thermal efficiency is the lower limit in the assumed range. In addition, from the turbine outlet temperature T0 of fig. 4, there is an influence of about-5% at the load of 50%, which means that the turbine outlet temperature T0 at the thermal efficiency at the upper limit in the assumed range becomes smaller by about 5% with respect to the turbine outlet temperature T0 at the lower limit in the assumed range.

From these experimental results, it is possible to specify gas measurement data having a large influence on each engine characteristic.

As is clear from fig. 4 relating to the thermal efficiency, the four gas measurement data of the scavenging pressure Ps, the exhaust pressure Pex, the scavenging amount Gs, and the exhaust amount Gex have a large influence on the thermal efficiency. Here, effective changes according to the thermal efficiency are found also for the exhaust gas temperature Tex and the turbine outlet temperature T0, but in the case of a low load such as 50%, no change (Tex) is found or the sign of the change is changed (T0), and therefore, the parameters are not suitable as parameters for stably estimating the thermal efficiency regardless of the magnitude of the load. In addition, although the scavenging pressure Ps and the scavenging gas amount Gs are measured in the present experiment because the two-stroke engine that performs the scavenging operation is used, it is considered that the teaching obtained from the result of the present experiment is also suitable for the four-stroke engine that does not perform the scavenging operation, and therefore the intake air pressure Pb and the intake air amount Pb that are respectively generalized can also be used for estimation of the thermal efficiency. The intake air pressure Pb/scavenging pressure Ps, intake air amount Gb/scavenging amount Gs, exhaust air pressure Pex, and exhaust air amount Gex determined in this way have a large influence on the thermal efficiency, and can be understood from the parameters indicating the state of the gas used for combustion of the fuel in the combustion portion 210.

As is apparent from fig. 5 relating to the compressor efficiency, six gas measurement data, i.e., the exhaust gas temperature Tex, the scavenging pressure Ps, the exhaust gas pressure Pex, the scavenging gas amount Gs, the exhaust gas amount Gex, and the turbine outlet temperature T0, have a large influence on the compressor efficiency. Here, regarding the scavenging temperature Ts, no effective change is found in accordance with the compressor efficiency because the scavenging temperature Ts is maintained within a fixed range by the charge air cooler 224 shown in fig. 2. However, in an engine configured such that the scavenging temperature Ts varies without providing the charge air cooler 224, it is estimated that the influence of the scavenging temperature Ts on the compressor efficiency is also large. That is, this is because, by analogy with the influence of the exhaust gas temperature Tex of the exhaust gas after combustion in the combustion portion 210 on the compressor efficiency in fig. 5, it is reasonably considered that the scavenging temperature Ts before combustion in the combustion portion 210 also similarly influences the compressor efficiency. In addition, in the present experiment, the scavenging temperature Ts, the scavenging pressure Ps, and the scavenging gas amount Gs were measured because the two-stroke engine that performs the scavenging operation was used, but it is considered that the teaching obtained from the results of the present experiment is also suitable for the four-stroke engine that does not perform the scavenging operation, and therefore the intake air temperature Tb, the intake air pressure Pb, and the intake air amount Gb, which are respectively obtained in a generalized manner, can also be used for estimating the compressor efficiency. The intake air pressure Pb/scavenging pressure Ps, intake air temperature Tb/scavenging temperature Ts, intake air amount Gb/scavenging amount Gs, exhaust air pressure Pex, exhaust air temperature Tex, exhaust air amount Gex, and turbine outlet temperature T0 determined as described above have a large influence on the compressor efficiency, and these parameters can be understood as parameters indicating the state of the gas after passing through the compressor 241 until being discharged from the turbine outlet pipe 233.

The same teaching is obtained with respect to fig. 6 relating to turbine efficiency as with respect to fig. 5 relating to compressor efficiency. That is, as described with reference to fig. 5, the intake air pressure Pb/scavenging pressure Ps, the intake air temperature Tb/scavenging temperature Ts, the intake air amount Gb/scavenging amount Gs, the exhaust pressure Pex, the exhaust gas temperature Tex, the exhaust gas amount Gex, and the turbine outlet temperature T0 are determined as gas measurement data having a large influence on the turbine efficiency. This is because the compressor 241 and the turbine 242 rotate coaxially in conjunction with each other, and thus parameters that affect the respective efficiencies are substantially the same.

Based on the above-described teaching shown in fig. 4 to 6, engine characteristic estimating unit 130 can efficiently estimate the characteristics of engine 200 as follows.

First, as is apparent from fig. 4 to 6, when the load of the engine 200 is low, such as 50% of the maximum load, the characteristic change of the engine 200 has a large influence on the respective gas measurement data. This is considered to be because the engine 200 is susceptible to various changes inside and outside the engine 200 when operating at a low load. Therefore, when engine 200 is operated at a low load, for example, at a load of 50% or less of the maximum load, engine characteristic estimating unit 130 can estimate the characteristic of engine 200 more effectively. Here, power saving can also be achieved by the engine characteristic estimating unit 130 not estimating the characteristic of the engine 200 when operating at a load higher than 50% of the maximum load.

When fig. 4 relating to the influence of the heat efficiency is compared with fig. 5 and 6 relating to the supercharger efficiency, it is understood that the influence of the change in the heat efficiency is different from the influence of the change in the supercharger efficiency even in the same gas measurement data. Taking the scavenging pressure Ps as an example, when operating at a load of 85%, the effect of the change in thermal efficiency of fig. 4 on the scavenging pressure Ps is about 10%, while the effect of the change in compressor efficiency of fig. 5 on the scavenging pressure Ps is about 7%. Further, the manner of change in the degree of influence of the thermal efficiency and the supercharger efficiency when the load of the engine 200 is changed is also different. That is, as the load changes to 50% → 75% → 85% → 100%, the degree of influence of the thermal efficiency change of fig. 4 on the scavenging pressure Ps changes to about 17% → about 11% → about 10% → about 8%, and the degree of influence of the compressor efficiency change of fig. 5 on the scavenging pressure Ps changes to about 12% → about 8% → about 7%.

As described above, when the load of the engine 200 changes, the influence of the thermal efficiency on each gas measurement data and the influence of the supercharger efficiency on each gas measurement data appear in different forms. The engine characteristic estimating unit 130 stores information on the degree of influence on the gas measurement data according to such a load change in the form of a table or the like for each of the thermal efficiency and the supercharger efficiency, thereby making it possible to estimate the thermal efficiency and the supercharger efficiency at the same time with high accuracy. Specifically, when the load of the engine 200 changes, the engine characteristic estimating unit 130 sequentially records gas measurement data (actually, gas measurement data sequentially recorded in the form of a difference calculation result with the gas estimation data) that changes in accordance with the change in the load by the history recording unit 132. The estimation unit 133 can extract the influence of the heat efficiency and the influence of the supercharger efficiency individually by comparing the sequentially recorded gas measurement data with the information on the influence of the heat efficiency and the supercharger efficiency according to the load change. In this way, the engine characteristic estimating unit 130 can accurately estimate the thermal efficiency and the supercharger efficiency based on the gas measurement data sequentially acquired at the time of load change.

In addition, although the above description has been made taking the thermal efficiency and the supercharger efficiency as examples, the present invention is not limited to this, and the above-described method can be applied to a plurality of arbitrary engine characteristics. That is, in the above example, the thermal efficiency and the supercharger efficiency can be estimated separately with high accuracy by utilizing the difference in the change tendency according to the load change between the thermal efficiency (fig. 4) and the supercharger efficiency (fig. 5/fig. 6), but a plurality of arbitrary engine characteristics having different change tendencies according to the load change can be similarly estimated individually.

Returning to fig. 1, the air temperature data acquisition unit 140 acquires air temperature data, which is a measured value of the temperature of the air before flowing into the compressor 241, from an air temperature sensor provided at the sensor installation position S0, and supplies the acquired air temperature data to the estimation unit 133. Since the estimation unit 133 can recognize the state of the outside air based on the supplied air temperature data, it is possible to estimate the characteristics of the engine 200 with high accuracy so as to eliminate the influence of disturbance from the outside air.

The engine characteristic estimation result output by the engine characteristic estimation device 100 as described above can be used for the following applications, for example.

When the actual engine characteristic estimation result deviates from the characteristic indicated by the engine model of the state estimating unit 120, the engine model is updated based on the actual engine characteristic estimation result. Thus, the engine model is a model reflecting the actual characteristics of engine 200, and therefore the state estimation accuracy of state estimating unit 120 can be improved.

The engine characteristic estimation result can be used for various controls of the engine 200. It is possible to perform high-precision control in view of the characteristics of the actual engine 200.

The engine characteristic estimation result can be used for monitoring and degradation diagnosis of the engine 200. It is possible to reliably identify an abnormality of the engine and to quickly respond thereto.

Fig. 7 is a schematic diagram showing the configuration of the engine characteristic estimation device 100 according to the second embodiment. Only the configuration of the engine characteristic estimating unit 130 is different from the engine characteristic estimating apparatus 100 according to the first embodiment shown in fig. 1.

The engine characteristic estimating unit 130 includes: a difference calculator 131 that calculates a difference between the gas measurement data and the gas estimation data; a history recording unit 132 that records history data of the difference calculation result of the difference calculator 131; a parameter adjusting unit 134 that adjusts a parameter in the engine model of the state estimating unit 120 based on the difference calculation result of the difference calculator 131 and the history data of the history recording unit 132; and an estimation unit 133 that estimates the characteristics of the engine 200 based on the adjustment amount in the parameter adjustment unit 134.

The parameter adjustment unit 134 adjusts the parameters in the engine model of the state estimation unit 120 so that the difference between the gas estimation data and the gas measurement data is reduced. As described in the first embodiment, when there is a difference between the gas estimation data and the gas measurement data, the actual characteristic of the engine 200 deviates from the characteristic mathematically modeled by the state estimating unit 120. In the present embodiment, the parameter adjustment unit 134 adjusts the parameters in the engine model so as to reduce the deviation of the characteristics. Thus, the engine model of the state estimating unit 120 is a model reflecting the actual characteristics of the engine 200, and the difference between the gas estimation data, which is the calculation result, and the gas measurement data, which is the actual measurement value, is reduced. Here, the parameter adjustment amount of the parameter adjustment unit 134 indicates the degree of deviation of the above-described characteristics, and the estimation unit 133 can estimate the actual characteristics of the engine 200 based on the parameter adjustment amount.

In the above configuration, in a stable system with little influence of disturbance or the like, the parameter adjustment unit 134 preferably adjusts the parameter in the engine model of the state estimation unit 120 so that the difference between the gas estimation data calculated by the difference calculator 131 and the gas measurement data becomes zero.

On the other hand, in a system that is affected by a large amount of interference or the like, since the difference calculation result temporarily changes depending on a sudden abnormality, it may not be appropriate to simply perform parameter adjustment so that the difference becomes zero. Therefore, the parameter adjusting unit 134 refers to the instantaneous value from the difference computing unit 131 and also refers to the history data recorded in the history recording unit 132, and thereby performs parameter adjustment when a constant difference is present for a certain period of time. The parameter adjusting unit 134 can recognize the state of the outside air based on the air temperature data supplied from the air temperature data acquiring unit 140, and can perform parameter adjustment while eliminating the influence of disturbance from the outside air. In the case where the parameter adjustment unit 134 adjusts the parameter in consideration of the supplementary information supplied from the history unit 132 and the air temperature data acquisition unit 140 as described above, the difference calculation result from the difference calculator 131 is not necessarily zero.

The present invention has been described above based on embodiments. It will be understood by those skilled in the art that the embodiments are illustrative, and various modifications can be made by combining the respective constituent elements and the respective processing steps, and such modifications are also within the scope of the present invention.

In the embodiment, the parameters measured at the sensor installation positions S1 and S2 for measuring the air supplied from the compressor 241 to the combustion section 210, the sensor installation positions S3 and S4 for measuring the gas discharged after combustion in the combustion section 210, and the sensor installation position S5 for measuring the gas having passed through the turbine 242 are exemplified by the pressure, the temperature, and the flow rate, but other parameters related to these gases may be measured. For example, the concentration, density, and component amount of the gas can be given.

In the embodiment, the air temperature sensor that measures the temperature of the outside air is provided at the sensor installation position S0, but a sensor that measures another parameter of the outside air may be provided and the measurement data may be supplied to the engine characteristic estimation device 100. For example, a pressure sensor or a flow rate sensor may be provided at S0. As in the embodiment, these pieces of outside air measurement data are used to reduce the influence of disturbance from outside air when estimating the characteristics of the engine 200.

The functional configuration of each device described in the embodiments can be realized by hardware resources, software resources, or cooperation of hardware resources and software resources. As the hardware resources, a processor, ROM, RAM, or other LSI can be used. As the software resource, a program such as an operating system or an application can be used.

In the embodiments disclosed in the present specification, in which a plurality of functions are provided in a distributed manner, some or all of the plurality of functions may be provided in a concentrated manner, and conversely, in the embodiments in which a plurality of functions are provided in a concentrated manner, some or all of the plurality of functions may be provided in a distributed manner. The functions may be integrated or distributed, and the functions may be configured to achieve the object of the invention.

Claims

1. An engine characteristic estimation device that estimates a characteristic of an engine, the engine comprising: a combustion unit that combusts air and fuel to generate power; a turbine rotated by gas discharged after combustion in the combustion section; and a compressor that rotates in conjunction with the turbine and compresses air supplied to the combustion unit, the engine characteristic estimation device including:

a gas measurement data acquisition unit that acquires gas measurement data that is a measurement value relating to at least one of air supplied to the combustion unit by the compressor, gas discharged after combustion in the combustion unit, and gas that has passed through the turbine;

a calculation section that calculates gas estimation data, which is an estimation value corresponding to the gas measurement data, based on an engine model representing characteristics of the engine and a fuel supply amount supplied to the combustion section; and

an engine characteristic estimating unit that estimates a characteristic of the engine based on a comparison of the gas measurement data and the gas estimation data.

2. The engine characteristic estimation device according to claim 1,

the engine is a marine engine having a rated rotation speed of 1000 rpm or less.

3. The engine characteristic estimation device according to claim 1 or 2,

the gas measurement data is a measurement value of at least one of a pressure, a temperature, and a flow rate of air supplied to the combustion unit by the compressor, gas discharged after combustion in the combustion unit, and gas passing through the turbine.

4. The engine characteristic estimation device according to claim 3,

the engine is provided with an air supply accommodating part which accommodates air supplied to the combustion part by the compressor,

the gas measurement data is a measurement value of at least one of a pressure, a temperature, and a flow rate of the air in the supply air storage unit.

5. The engine characteristic estimation device according to claim 3,

the engine includes an exhaust gas housing that houses gas that is discharged after being combusted in the combustion section,

the gas measurement data is a measurement value of at least one of a pressure, a temperature, and a flow rate of the gas in the exhaust gas accommodating portion.

6. The engine characteristic estimation device according to claim 3,

the gas measurement data is a measurement value of the temperature of the gas after passing through the turbine.

7. The engine characteristic estimation device according to claim 1,

further comprising a temperature data acquisition unit that acquires temperature data that is a measured value of the temperature of the air before flowing into the compressor,

the engine characteristic estimation portion estimates a characteristic of the engine based on the air temperature data.

8. The engine characteristic estimation device according to claim 1,

the engine characteristic estimating unit estimates at least one of an efficiency of the compressor and an efficiency of the turbine.

9. The engine characteristic estimation device according to claim 1,

the gas measurement data is a measurement value of at least one of a pressure and a flow rate of air supplied to the combustion unit by the compressor and gas discharged after combustion in the combustion unit,

the engine characteristic estimation portion estimates a thermal efficiency of the combustion portion.

10. The engine characteristic estimation apparatus according to claim 9,

the engine characteristic estimating unit estimates at least one of the thermal efficiency, the efficiency of the compressor, and the efficiency of the turbine based on the data in which the tendency of change in the thermal efficiency when the load of the engine changes and the data in which the tendency of change in at least one of the efficiency of the compressor and the efficiency of the turbine when the load of the engine changes are recorded, from the gas measurement data and the gas estimation data acquired when the load of the engine changes.

11. The engine characteristic estimation device according to claim 1,

the engine characteristic estimation unit includes a parameter adjustment unit that adjusts a parameter in the engine model so that a difference between the gas estimation data and the gas measurement data is reduced, and estimates a characteristic of the engine based on an amount of the adjustment.

12. The engine characteristic estimation device according to claim 1,

the calculation unit calculates the gas estimation data based on measurement data of a rotation speed of a rotation drive unit that generates rotational power in the combustion unit.

13. The engine characteristic estimation device according to claim 1,

the calculation unit calculates a parameter relating to a state of the engine in addition to the gas estimation data.

14. The engine characteristic estimation device according to claim 1,

the engine characteristic estimating section estimates the characteristic of the engine when a load of the engine is 50% or less of a maximum load of the engine.

15. An engine characteristic estimation method for estimating a characteristic of an engine, the engine comprising: a combustion unit that combusts air and fuel to generate power; a turbine rotated by gas discharged after combustion in the combustion section; and a compressor that rotates in conjunction with the turbine and compresses air supplied to the combustion unit, wherein the engine characteristic estimation method includes:

a gas measurement data acquisition step of acquiring gas measurement data, which is a measurement value relating to at least one of air supplied to the combustion unit by the compressor, gas discharged after combustion in the combustion unit, and gas having passed through the turbine;

a calculation step of calculating gas estimation data, which is an estimation value corresponding to the gas measurement data, based on an engine model indicating characteristics of the engine and a fuel supply amount supplied to the combustion portion; and

an engine characteristic estimating step of estimating a characteristic of the engine based on a comparison of the gas measurement data and the gas estimation data.

16. A computer-readable storage medium storing an engine characteristic estimation program that estimates a characteristic of an engine, the engine comprising: a combustion unit that combusts air and fuel to generate power; a turbine rotated by gas discharged after combustion in the combustion section; and a compressor that rotates in conjunction with the turbine and compresses air supplied to the combustion unit, wherein the engine characteristic estimation program causes the computer to execute: