System for identifying fuel for work machine and method for identifying fuel for work machine

Abstract

A fuel property sensor (1) detects the density and / or dielectric constant as a physical property value of fuel containing carbon-neutral fuel. A controller (50) estimates the type of fuel on the basis of the physical property value detected by the fuel property sensor (1).

Description

Fuel identification system for work machine and fuel identification method for work machine

[0001] The present disclosure relates to a fuel identification system for a work machine and a fuel identification method for a work machine.

[0002] A fuel identification device for a work machine is disclosed, for example, in Japanese Patent Laid-Open No. 2008-261759 (Patent Document 1). Patent Document 1 describes a device that distinguishes between light oil, kerosene, and heavy oil as fuel for a work machine.

[0003] Japanese Patent Application Laid-Open No. 2008-261759

[0004] In recent years, the use of carbon-neutral fuels in work machines has been considered. However, Patent Document 1 does not disclose a technology for accurately identifying carbon-neutral fuels.

[0005] An object of the present disclosure is to provide a fuel identification system for a work machine and a fuel identification method for a work machine that can accurately identify carbon-neutral fuels.

[0006] A fuel identification system for a work machine according to the present disclosure includes a fuel property sensor and a controller. The fuel property sensor detects at least density as a physical property value of a fuel including a carbon-neutral fuel. The controller estimates the type of fuel based on the physical property value detected by the fuel property sensor.

[0007] Another fuel identification system for a work machine disclosed herein includes a fuel property sensor and a controller. The fuel property sensor detects at least the dielectric constant as a physical property value of the fuel, including the carbon-neutral fuel. The controller estimates the type of fuel based on the physical property value detected by the fuel property sensor.

[0008] A fuel identification method for a work machine according to the present disclosure includes the following steps: acquiring at least density as a physical property value of a fuel including a carbon-neutral fuel; and estimating the type of fuel based on the acquired physical property value.

[0009] Another fuel identification method for a work machine disclosed herein includes the following steps: acquiring at least the dielectric constant as a physical property value of a fuel including a carbon-neutral fuel; and estimating the type of fuel based on the acquired physical property value.

[0010] According to the present disclosure, it is possible to realize a fuel identification system for a work machine and a fuel identification method for a work machine that can accurately identify carbon-neutral fuels.

[0011] 1 is a diagram showing the configuration of a work machine according to an embodiment of the present disclosure. FIG. 2 is a circuit diagram of a fuel. FIG. 3 is a diagram showing the configuration of a fuel identification system for a work machine according to an embodiment of the present disclosure. FIG. 4 is a functional block diagram of a controller employed in the system of FIG. 3. FIG. 5 is a flow diagram showing a fuel identification method for a work machine according to an embodiment of the present disclosure. FIG. 6 is a diagram showing the results of measuring the physical property values ​​of each of diesel, FAME, and HVO. FIG. 7 is a diagram showing the results of measuring the physical property values ​​of a fuel obtained by mixing diesel and HVO. FIG. 8 is a diagram showing the results of measuring the physical property values ​​of a fuel obtained by mixing diesel and FAME. FIG. 9 is a flow diagram showing a method for estimating the type of fuel (diesel, FAME, HVO, mixed fuel) from the dielectric constant and density of the fuel.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the specification and drawings, identical or corresponding components are designated by the same reference numerals, and redundant descriptions will not be repeated. In addition, in the drawings, configurations may be omitted or simplified for the sake of convenience. Furthermore, at least some of the embodiments and modified examples may be combined with each other in any desired manner.

[0013] In the following description, the fore-aft direction refers to the direction in which the boom 16 extends from the base end to the tip end in a plan view. The left-right direction refers to the direction perpendicular to the fore-aft direction in a plan view. The up-down direction refers to the direction perpendicular to a plane that includes the fore-aft direction and the left-right direction, which are perpendicular to each other.

[0014] <Configuration of work machine 10> Figure 1 is a diagram that shows a schematic configuration of a work machine in one embodiment of the present disclosure. As shown in Figure 1, the work machine 10 in this embodiment is, for example, a hydraulic excavator. However, the work machine 10 is not limited to hydraulic excavators, and may be any work machine 10 that has a work implement and uses fuel, including carbon-neutral fuel, during operation, such as a wheel loader, bulldozer, motor grader, dump truck, or forklift.

[0015] The fuel used to operate the work machine 10 includes carbon-neutral (CN) fuel. As long as the fuel used to operate the work machine 10 includes carbon-neutral fuel, it may also include other fuels such as diesel oil. Carbon-neutral combustion refers to fuel that does not increase the concentration of carbon dioxide (CO2) in the atmosphere throughout the entire process from production to use. Carbon-neutral fuels include FAME (Fatty Acid Methyl Ester), paraffin fuel, etc.

[0016] FAME is a bioester made by esterifying bio-derived fatty acid triglycerides. FAME is a fatty acid methyl ester produced from corn, palm, waste cooking oil, etc. Paraffin fuel is a fuel whose components are mostly paraffin, and paraffin diesel fuel meets the EN15940 standard. Paraffin fuels include, for example, HVO (Hydrotreated Vegetable Oil), synthetic fuel, and GTL (Gas to Liquids).

[0017] Synthetic fuel is a fuel produced by synthesizing carbon dioxide and hydrogen (H2). Among synthetic fuels, synthetic fuels produced using hydrogen produced with renewable electricity and carbon dioxide separated and concentrated from the atmosphere or from a combustion reaction are called e-fuels.

[0018] GTL is a liquid fuel synthesized from hydrocarbon gas. Fuel containing carbon-neutral fuel is supplied to, for example, the engine of the work machine 10. The fuel is combusted explosively in the engine, and power is obtained from the force of the explosion.

[0019] A hydraulic excavator 10 as an example of a work machine 10 has a main body 11 and a work implement 12. The main body 11 has a revolving body 13 and a traveling body 15.

[0020] The running body 15 has a pair of crawler tracks 15Cr and a travel motor 15M. The work machine 10 is capable of traveling by rotation of the crawler tracks 15Cr. The travel motor 15M is provided as a drive source for the running body 15.

[0021] The rotating body 13 is disposed on and supported by the running body 15. The rotating body 13 can be rotated relative to the running body 15 about a rotation axis RX by a rotation motor (not shown). The rotation axis RX is an imaginary straight line that serves as the rotation center of the rotating body 13.

[0022] The rotating body 13 has a driver's cab 14. A driver's seat 14S is provided in the driver's cab 14 for an operator to sit in. The operator sits in the driver's cab 14 and can operate the work equipment 12, rotate the rotating body 13 relative to the traveling body 15, and travel the hydraulic excavator 10 using the traveling body 15. A fuel tank 6 (not shown in FIG. 1 ) is mounted on the rotating body 13.

[0023] The work implement 12 is supported by the revolving unit 13. The work implement 12 has a boom 16, an arm 17, and a bucket 18. The work implement 12 further has a boom cylinder 19a, an arm cylinder 19b, and a bucket cylinder 19c.

[0024] The boom 16 is rotatably connected to the main body 11. Specifically, the base end of the boom 16 is rotatably connected to the revolving unit 13 with a boom foot pin BF as a fulcrum. The arm 17 is rotatably connected to the boom 16. Specifically, the base end of the arm 17 is rotatably connected to the tip of the boom 16 with a boom top pin BT as a fulcrum. The bucket 18 is rotatably connected to the arm 17. Specifically, the base end of the bucket 18 is rotatably connected to the tip of the arm 17 with an arm top pin AT as a fulcrum.

[0025] The boom 16 can be driven by a boom cylinder 19a relative to the main body 11. By this driving, the boom 16 can be rotated in the vertical direction relative to the revolving body 13 with a boom foot pin BF as a fulcrum.

[0026] The arm 17 can be driven by an arm cylinder 19b relative to the boom 16. By this drive, the arm 17 can rotate up and down or back and forth relative to the boom 16 with the boom top pin BT as a fulcrum.

[0027] The bucket 18 can be driven by a bucket cylinder 19c relative to the arm 17. By this drive, the bucket 18 can rotate up and down or back and forth relative to the arm 17 with the arm top pin AT as a fulcrum.

[0028] The rotating body 13 has a drive source. The drive source is, for example, an engine, which generates power when supplied with fuel including the above-mentioned carbon-neutral fuel. The drive source is disposed behind the operator's cab 14. The drive source is covered by an exterior panel 13a.

[0029] In this embodiment, the physical property values ​​of the fuel supplied to the driving source are detected. The detected physical property values ​​include the density and dielectric constant of the fuel. The detected physical property values ​​may include the viscosity, resistance, and temperature of the fuel in addition to the density and dielectric constant. The detected physical property value may be the density of the fuel alone, the dielectric constant of the fuel alone, or both the density and dielectric constant of the fuel. The detected physical property value may also be any combination of the density, dielectric constant, viscosity, resistance, and temperature of the fuel.

[0030] Furthermore, in this embodiment, as will be described later, the type of fuel and the fuel mixture ratio are estimated based on the detected physical property values ​​of the fuel. The effect of reducing carbon dioxide emissions due to the use of carbon-neutral fuel by the work machine 10 is calculated based on the estimated type of fuel and the fuel mixture ratio. Therefore, in this embodiment, it is possible to constantly monitor the effect of reducing carbon dioxide emissions.

[0031] <Fuel Circuit> Next, an example of a fuel circuit in a work machine will be described with reference to FIG.

[0032] 2 is a circuit diagram of a fuel circuit. As shown in FIG. 2, an example of a fuel circuit includes a fuel property sensor 1, pumps 3a and 3b, filters 4a and 4b, a common rail 5, and a fuel tank 6.

[0033] Fuel is stored in the fuel tank 6. The fuel contains the carbon-neutral fuel described above. A pump 3a is connected to the fuel tank 6. The pump 3a pumps up the fuel stored in the fuel tank 6 when it is operating. A filter 4a is disposed in the flow path connecting the fuel tank 6 and the pump 3a. The fuel filtered by the filter 4a is pumped up by the pump 3a.

[0034] Pump 3a is connected to pump 3b. When pump 3b operates, it further pumps the fuel pumped by pump 3a. A filter 4b is disposed in the flow path connecting pump 3a and pump 3b. The fuel is further filtered by filter 4b and then pumped to pump 3b.

[0035] A common rail 5 is connected to the pump 3b. The fuel pumped up by the pump 3b is supplied to the common rail 5. The common rail 5 stores fuel at high pressure. The common rail 5 distributes the stored high-pressure fuel to each cylinder of the engine. When the fuel is injected into each cylinder at high pressure, it becomes atomized and mixes well with the air. This promotes fuel vaporization and results in near-complete combustion.

[0036] A fuel property sensor 1 is provided to detect the physical property values ​​of the fuel. The fuel property sensor 1 is disposed, for example, in the passage between the filter 4a and the pump 3a. The fuel property sensor 1 may be disposed in the passage between the fuel tank 6 and the filter 4a, or may be disposed inside the fuel tank 6 or inside the pump 3a. The location of the fuel property sensor 1 is not limited to the above, and may be in another location. For example, the fuel property sensor 1 may be disposed between the pump 3a and the filter 4b, or between the filter 4b and the pump 3b. It is preferable that the fuel property sensor 1 be disposed in a location where fuel flows at a constant speed and where contamination is minimized.

[0037] The fuel property sensor 1 detects the physical properties of the fuel. The physical properties of the fuel detected by the fuel property sensor 1 include, for example, the density, dielectric constant, viscosity, resistance, and temperature of the fuel. The fuel property sensor 1 includes, for example, a quartz tuning fork oscillator and a resistance temperature detector. When an AC voltage is applied to the quartz tuning fork oscillator in the fuel to cause it to oscillate, a capacitor is formed between the electrode and the surrounding fuel. The fuel's capacitance changes depending on the dielectric constant and resistance of the fuel. Therefore, the dielectric constant and resistance of the fuel can be detected by detecting the capacitance of the capacitor. Furthermore, the amplitude and phase of the vibration change due to a reaction force from the surrounding fuel. The viscosity and density of the fuel can be detected from the changes in the amplitude and phase of this vibration. Furthermore, the resistance temperature detector can measure the fuel temperature.

[0038] The fuel property sensor 1 is electrically connected to the controller 50. The fuel property sensor 1 outputs to the controller 50 an electrical signal indicating the detected physical property value of the fuel.

[0039] There is also provided a fuel level sensor 7. The fuel level sensor 7 detects the amount of fuel stored in the fuel tank 6. The fuel level sensor 7 is electrically connected to the controller 50. The fuel level sensor 7 outputs an electrical signal indicating the detected amount of fuel stored in the fuel tank 6 to the controller 50.

[0040] <Fuel Identification System for Work Machine 10> Next, a fuel identification system for the work machine 10 according to one embodiment of the present disclosure will be described with reference to FIG.

[0041] 3 is a diagram showing the configuration of a fuel identification system for a work machine 10 in one embodiment of the present disclosure. As shown in FIG. 3, the fuel identification system for a work machine 10 includes, for example, the work machine 10 and a server 20.

[0042] The work machine 10 has a fuel property sensor 1, a controller 50, a monitor 2, and a fuel level sensor 7. The fuel property sensor 1, the monitor 2, and the fuel level sensor 7 are each electrically connected to the controller 50.

[0043] A signal indicating the physical property values ​​of the fuel detected by the fuel property sensor 1 is output to the controller 50 of the work machine 10. The controller 50 estimates the type of fuel and the mixing ratio of carbon-neutral fuel in the fuel based on the acquired physical property values ​​of the fuel. The controller 50 also calculates the carbon dioxide emission reduction effect of using carbon-neutral fuel based on the above mixing ratio, the amount of fuel used by the work machine 10, and the carbon dioxide reduction rate for each type of carbon-neutral fuel. The controller 50 may also calculate the amount of fuel used by the work machine 10 based on the amount of fuel stored in the fuel tank 6 detected by the fuel level sensor 7.

[0044] The controller 50 outputs information such as the type of fuel, the mixing ratio of carbon-neutral fuel in the fuel, and the effect of reducing carbon dioxide emissions due to the use of carbon-neutral fuel to the monitor 2. The monitor 2 displays an image based on the information obtained from the controller 50.

[0045] The monitor 2 may be mounted on the work machine 10, or may be located remotely outside the work machine 10. The monitor 2 may be, for example, a tablet or personal computer of a customer or service technician, or may be a monitor for a management computer of a work machine manufacturer. When the monitor 2 is located remotely outside the work machine 10, the monitor 2 may be connected wirelessly to the controller 50 or the like. The monitor 2 may also be connected by wire or wirelessly to a server 20 located remote from the work machine 10.

[0046] A signal indicating the physical property values ​​of the fuel detected by the fuel property sensor 1 is output to a server 20 provided outside the work machine 10. In addition, a signal indicating the amount of fuel stored in the fuel tank 6 detected by the fuel level sensor 7 is output to the server 20. The signal indicating the physical property values ​​of the fuel detected by the fuel property sensor 1 and the signal indicating the amount of fuel stored detected by the fuel level sensor 7 may each be transmitted wirelessly to the server 20. The server 20 is, for example, a server owned by a construction machine manufacturer.

[0047] The server 20 has the same functions as the controller 50. In other words, the server 20 estimates the type of fuel and the mixing ratio of carbon-neutral fuel in the fuel based on the acquired physical property values ​​of the fuel. The server 20 also calculates the carbon dioxide emission reduction effect of using carbon-neutral fuel based on the above mixing ratio, the amount of fuel used by the work machine 10, and the carbon dioxide reduction rate for each type of carbon-neutral fuel. The server 20 may also calculate the amount of fuel used by the work machine 10 based on the amount of fuel stored in the fuel tank 6 detected by the fuel level sensor 7.

[0048] <Functional Blocks of Controller 50> Next, functional blocks of the controller 50 will be described with reference to FIG.

[0049] Fig. 4 is a functional block diagram of a controller employed in the system of Fig. 3. As shown in Fig. 4, the controller 50 has a fuel property value acquisition unit 51, a fuel estimation unit 52, a carbon dioxide (CO2) reduction effect calculation unit 53, an output control unit 54, and a memory 55. The fuel property value acquisition unit 51 acquires the property values ​​of the fuel from the fuel property sensor 1.

[0050] The fuel estimation unit 52 acquires the physical property values ​​of the fuel from the fuel physical property value acquisition unit 51. The fuel estimation unit 52 estimates the type of fuel from the acquired physical property values ​​of the fuel based on the relationship between the physical property values ​​of the fuel and the type of fuel (physical property value-fuel type relationship). The fuel estimation unit 52 also estimates the fuel mixing ratio from the acquired physical property values ​​of the fuel based on the relationship between the physical property values ​​of the fuel and the mixing ratio of carbon-neutral fuel in the fuel (physical property value-mixing ratio relationship).

[0051] The fuel estimation unit 52 may estimate only the type of fuel, only the fuel mixture ratio, or both the type of fuel and the mixture ratio. When making the estimation, the fuel estimation unit 52 refers to at least one of the physical property value-fuel type relationship and the physical property value-mixture ratio relationship stored in advance in the memory 55.

[0052] The physical property value-fuel type relationship and the physical property value-mixture ratio relationship may be, for example, the data shown in Figures 6 to 8. For example, the data shown in Figures 6 to 8 is stored in memory 55, and fuel estimation unit 52 estimates the type of fuel and the mixture ratio of the fuel from the acquired physical property values ​​of the fuel (for example, density, dielectric constant, viscosity, resistance value, temperature, etc.) by referring to the data shown in Figures 6 to 8. Specific methods for estimating the type of fuel and the method for estimating the mixture ratio of the fuel will be described later.

[0053] The CO2 reduction effect calculation unit 53 calculates the effect of reducing carbon dioxide emissions by using carbon-neutral fuel using the following formula (1).

[0054]

[0055] The "CO2 reduction rate by CN fuel" in formula (1) is the reduction rate (%) of carbon dioxide emissions for each type of carbon-neutral fuel. The "CO2 reduction rate by CN fuel" may be the reduction rate used for calculations by government agencies for each type of carbon-neutral fuel. Alternatively, the reduction rate proposed by the manufacturer with the highest market share may be used. Alternatively, the lowest reduction rate published by each manufacturer of each fuel may be used as the representative.

[0056] The carbon dioxide emission reduction rate for each type of carbon-neutral fuel is stored in advance in memory 55. When calculating the carbon dioxide emission reduction effect, CO2 reduction effect calculation unit 53 refers to the carbon dioxide emission reduction rate for each type of carbon-neutral fuel stored in memory 55 based on the estimated fuel type.

[0057] The "mixing ratio of CN fuel" in formula (1) is the mixing ratio of each type of carbon-neutral fuel in the fuel. The CO2 reduction effect calculation unit 53 acquires the fuel mixing ratio from the fuel estimation unit 52 as the "mixing ratio of CN fuel."

[0058] The "amount of fuel used" in formula (1) is calculated by multiplying fuel consumption (L / h) by cumulative operating time (h). The "amount of fuel used" may be calculated daily, annually, or continuously monitored. A representative fuel consumption rate determined by design for each model of work machine 10 may be used for fuel consumption. Alternatively, a value calculated for each work machine 10 from the amount of fuel used calculated from the detection value of the fuel level sensor 7 and the operating time of the work machine 10 may be used for fuel consumption. The annual operating time is calculated, for example, from the date and cumulative operating time.

[0059] Specifically, the CO2 reduction effect calculation unit 53 calculates the effect of reducing carbon dioxide emissions by using carbon-neutral fuel as follows.

[0060] First, the CO2 reduction effect calculation unit 53 obtains from the memory 55 the carbon dioxide emission reduction rate for each type of fuel detected by the fuel property sensor 1. The reduction rates for diesel, HVO, and FAME are, for example, 0%, 90%, and 60%. The CO2 reduction effect calculation unit 53 also obtains the fuel blend ratio detected by the fuel property sensor 1. For example, if the HVO content is 25%, the blend ratio of HVO as a carbon-neutral fuel is 25%. The CO2 reduction effect calculation unit 53 then multiplies the obtained reduction rate by the blend ratio to calculate a reduction coefficient. For example, if the HVO content is 25%, the calculation is: reduction rate 90% × blend ratio 0.25 = reduction coefficient 0.225. The CO2 reduction effect calculation unit 53 multiplies the calculated reduction coefficient 0.225 by the amount of fuel used to calculate the carbon dioxide emission reduction effect of using carbon-neutral fuel.

[0061] The CO2 reduction effect calculation unit 53 outputs a signal indicating the calculated reduction effect of carbon dioxide emissions to the output control unit 54. The CO2 reduction effect calculation unit 53 may also output a signal indicating each of the type of fuel and the fuel mixing ratio estimated by the fuel estimation unit 52 to the output control unit 54.

[0062] The output control unit 54 acquires signals indicating the effect of reducing carbon dioxide emissions, the type of fuel, and the fuel mixture ratio. Based on the acquired signals, the output control unit 54 outputs a control signal to the monitor 2 to control the display content of the monitor 2. The output control unit 54 controls the monitor 2 to display the effect of reducing carbon dioxide emissions, the type of fuel, and the fuel mixture ratio as necessary.

[0063] The controller 50 includes a processor, a main memory, and a storage. The processor is, for example, a central processing unit (CPU). The main memory includes, for example, a nonvolatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM).

[0064] The controller 50 may be mounted on the work machine 10, or may be located remotely outside the work machine 10. When the controller 50 is located remotely outside the work machine 10, the controller 50 may be wirelessly connected to the fuel property sensor 1, the fuel level sensor 7, the monitor 2, etc. The controller 50 may be stored in a server 20 located remotely from the work machine 10.

[0065] The controller 50 reads the program stored in the storage, loads it into the main memory, and executes predetermined processing in accordance with the program. The program may also be distributed to the controller 50 via a network.

[0066] <Work Machine Fuel Identification Method> Next, a work machine fuel identification method according to one embodiment of the present disclosure will be described with reference to FIGS. 4 and 5. FIG.

[0067] Fig. 5 is a flow diagram showing a fuel identification method for a work machine according to one embodiment of the present disclosure. As shown in Figs. 4 and 5, the fuel property sensor 1 detects the physical property values ​​of fuel, including carbon-neutral fuel. The fuel physical property value acquisition unit 51 of the controller 50 acquires the physical property values ​​of the fuel from the fuel property sensor 1 (step S1: Fig. 5). As described above, the physical property value of the fuel may be only the density of the fuel, only the dielectric constant of the fuel, or both the density and dielectric constant of the fuel, or a combination of these with other physical property values ​​(for example, viscosity, resistance, temperature).

[0068] The fuel physical property value acquisition unit 51 outputs the acquired physical property values ​​to the fuel estimation unit 52. The fuel estimation unit 52 estimates at least one of the fuel type and the mixing ratio of carbon-neutral fuel in the fuel from the acquired physical property values ​​of the fuel, based on at least one of the physical property value-fuel type relationship and the physical property value-mixing ratio relationship (step S2: FIG. 5). When estimating the fuel type and the mixing ratio of carbon-neutral fuel in the fuel, the fuel estimation unit 52 refers to the physical property value-fuel type relationship and the physical property value-mixing ratio relationship stored in memory 55.

[0069] The fuel estimation unit 52 outputs the estimated fuel type and the mixing ratio of carbon-neutral fuel in the fuel to the CO2 reduction effect calculation unit 53. The CO2 reduction effect calculation unit 53 uses the acquired fuel type and mixing ratio of carbon-neutral fuel in the fuel to calculate the carbon dioxide emission reduction effect by using the carbon-neutral fuel based on the above formula (1) (step S3: FIG. 5).

[0070] When calculating the reduction effect using equation (1), the CO2 reduction effect calculation unit 53 may calculate the fuel consumption amount in equation (1) using the amount of stored fuel detected by the fuel level sensor 7.

[0071] The CO2 reduction effect calculation unit 53 outputs a signal indicating the calculated reduction effect of carbon dioxide emissions to the output control unit 54. The CO2 reduction effect calculation unit 53 may also output a signal indicating each of the type of fuel and the fuel mixing ratio estimated by the fuel estimation unit 52 to the output control unit 54.

[0072] The output control unit 54 outputs a control signal to the monitor 2 based on the acquired signal to control the display content of the monitor 2. The output control unit 54 controls the monitor 2 to display each of the carbon dioxide emission reduction effect, the type of fuel, and the fuel mixing ratio.

[0073] In this way, the fuel identification method for the work machine 10 according to this embodiment is carried out. <Examples> Next, the studies carried out by the present inventors regarding the relationships between various fuels and their physical property values ​​will be described with reference to FIGS.

[0074] Fig. 6 is a diagram showing the results of measuring the physical properties of diesel, FAME, and HVO. Fig. 7 is a diagram showing the results of measuring the physical properties of a fuel obtained by mixing diesel and HVO. Fig. 8 is a diagram showing the results of measuring the physical properties of a fuel obtained by mixing diesel and FAME.

[0075] In Figure 7, HVO 20%, HVO 40%, HVO 60%, and HVO 80% indicate a blend of diesel and HVO. HVO 20%, HVO 40%, HVO 60%, and HVO 80% indicate that the HVO content of the total fuel is 20%, 40%, 60%, and 80%, respectively. HVO 100% indicates that the fuel is composed solely of HVO.

[0076] 8, FAME 20%, FAME 40%, FAME 60%, and FAME 80% indicate a blend of diesel and FAME, respectively. FAME 20%, FAME 40%, FAME 60%, and FAME 80% indicate that the blend ratio of FAME to the total fuel is 20%, 40%, 60%, and 80%, respectively. FAME 100% indicates that the fuel is composed solely of FAME.

[0077] The inventors used a fuel property sensor to detect the relationship between the temperature and the physical properties (dielectric constant, viscosity, density, resistivity) of various fuels (diesel oil, FAME, HVO). The results are shown in Figure 6.

[0078] As shown in Figure 6, the resistance values ​​of diesel and HVO are very close across the entire range of temperatures measured. This indicates that it is difficult to identify fuel types based on resistance values. Furthermore, even for the same type of fuel, the viscosity varies greatly between fuels used in summer and winter. This makes it difficult to identify fuel types based on viscosity.

[0079] On the other hand, for density and dielectric constant, the relationship was FAME > diesel > HVO across the entire temperature range measured. This shows that the type of fuel can be identified by density alone, dielectric constant alone, or both density and dielectric constant.

[0080] In particular, since the densities of diesel, FAME, and HVO differ greatly from one another, it is possible to distinguish between diesel, FAME, and HVO based on density alone. Furthermore, the dielectric constants of diesel and FAME are significantly different from each other, whereas the dielectric constants of diesel and HVO are close to each other. Therefore, it was found that dielectric constant is effective in distinguishing between diesel and FAME. On the other hand, it was found that dielectric constant is disadvantageous in distinguishing between diesel and HVO. Therefore, it was found that diesel, FAME, and HVO can be distinguished more accurately by combining density with dielectric constant. In other words, it was found that diesel, FAME, and HVO can be distinguished more accurately by distinguishing between the dielectric constant of diesel and FAME based on dielectric constant and by distinguishing between diesel and HVO based on density.

[0081] From the above, the type of fuel can be estimated by using only the density, only the dielectric constant, or both the density and the dielectric constant detected by the fuel property sensor 1.

[0082] The inventors also used a fuel property sensor to detect the relationship between the temperature and the physical properties (dielectric constant, viscosity, density, resistivity) of each fuel by changing the blend ratio of diesel fuel and HVO. The results are shown in Figure 7.

[0083] As shown in Figure 7, the resistance values ​​of fuels with each mixture ratio are close to each other across the entire measured temperature range. This makes it difficult to distinguish fuel mixture ratios based on resistance values. Furthermore, as noted in Figure 6, the viscosity of the same type of fuel varies greatly between fuels used or between summer and winter fuels. This makes it difficult to distinguish fuel mixture ratios based on viscosity.

[0084] On the other hand, it was found that the physical property values ​​(density, dielectric constant) of fuels at each mixture ratio were different from each other across the entire temperature range measured. Therefore, it was found that the mixture ratio of fuels can be identified by density alone, dielectric constant alone, or both density and dielectric constant.

[0085] From the above, the mixture ratio of fuel can be estimated by using only the density, only the dielectric constant, or both the density and the dielectric constant detected by the fuel property sensor 1.

[0086] The inventors also used a fuel property sensor to measure the relationship between the temperature and the physical properties (dielectric constant, viscosity, density, resistivity) of each fuel by changing the blend ratio of diesel fuel to FAME. The results are shown in Figure 8.

[0087] As shown in Figure 8, the resistance values ​​of fuels with FAME mixture ratios of 80%, 60%, and 40% are close to each other in the relatively low temperature range of the measured temperatures. Therefore, it was found that it is difficult to distinguish the fuel mixture ratio based on the resistance value. Furthermore, as mentioned in Figure 6, the viscosity of the same type of fuel varies greatly depending on the fuel used or between summer and winter fuels. Therefore, it is difficult to distinguish the fuel mixture ratio based on the viscosity.

[0088] On the other hand, it was found that the physical property values ​​(density, dielectric constant) of fuels at each mixture ratio were different from each other across the entire temperature range measured. Therefore, it was found that the mixture ratio of fuels can be identified by density alone, dielectric constant alone, or both density and dielectric constant.

[0089] From the above, the mixture ratio of fuel can be estimated by using only the density, only the dielectric constant, or both the density and the dielectric constant detected by the fuel property sensor 1.

[0090] <Method of Estimating Fuel Type> Next, a method of estimating fuel type will be described with reference to FIGS.

[0091] As shown in Figure 8, the dielectric constant of 100% FAME is higher than that of diesel oil alone, and is also higher than that of blends of diesel oil and FAME (FAME 20%, FAME 40%, FAME 60%, FAME 80%). The dielectric constants of blends of diesel oil and FAME (FAME 20%, FAME 40%, FAME 60%, FAME 80%) are also higher than that of diesel oil alone.

[0092] 7, the dielectric constant of diesel alone is higher than that of 100% HVO, and is also higher than that of blends of diesel and HVO (20% HVO, 40% HVO, 60% HVO, 80% HVO).The dielectric constants of blends of diesel and HVO (20% HVO, 40% HVO, 60% HVO, 80% HVO) are also higher than that of 100% HVO.

[0093] From the above, it can be seen that in terms of dielectric constant, the relationship is FAME > mixed fuel of FAME and diesel > diesel > mixed fuel of HVO and diesel > HVO.

[0094] As shown in Figure 8, the density of 100% FAME is higher than that of diesel oil alone, and is also higher than that of blends of diesel oil and FAME (20%, 40%, 60%, and 80% FAME).Furthermore, the density of blends of diesel oil and FAME (20%, 40%, 60%, and 80% FAME) is also higher than that of diesel oil alone.

[0095] 7, the density of diesel alone is higher than that of 100% HVO, and is also higher than the densities of blended fuels of diesel and HVO (20% HVO, 40% HVO, 60% HVO, 80% HVO).The densities of blended fuels of diesel and HVO (20% HVO, 40% HVO, 60% HVO, 80% HVO) are also higher than the density of 100% HVO.

[0096] From the above, it can be seen that in terms of density, the relationship is FAME > FAME and diesel blend > diesel > HVO and diesel blend > HVO.

[0097] Based on the above relationship between dielectric constant and density, the type of fuel is estimated as follows: Fig. 9 is a flow chart showing a method for estimating the type of fuel (diesel oil, FAME, HVO, or mixed fuel) from the dielectric constant and density of the fuel. As shown in Fig. 9, it is determined whether the dielectric constant is equal to or greater than a first threshold value (step S21). If the dielectric constant is equal to or greater than the first threshold value, the type of fuel is estimated to be FAME (step S31).

[0098] It is determined whether the dielectric constant is less than the first threshold and greater than or equal to the second threshold (step S22). If the dielectric constant is less than the first threshold and greater than or equal to the second threshold, the type of fuel is estimated to be a mixed fuel of FAME and diesel (step S32).

[0099] It is determined whether the dielectric constant is less than the second threshold and the density is equal to or greater than the third threshold (step S23). If the dielectric constant is less than the second threshold and the density is equal to or greater than the third threshold, the type of fuel is estimated to be diesel oil (step S33).

[0100] It is determined whether the dielectric constant is less than the second threshold and the density is less than the third threshold and equal to or greater than the fourth threshold (step S24). If the dielectric constant is less than the second threshold and the density is less than the third threshold and equal to or greater than the fourth threshold, it is estimated that the fuel is a blend of diesel and HVO (step S34).

[0101] It is determined whether the dielectric constant is less than the second threshold and the density is less than the fourth threshold (step S25). If the dielectric constant is less than the second threshold and the density is less than the fourth threshold, the type of fuel is estimated to be HVO (step S35).

[0102] The fuel type estimation method of this embodiment is carried out as described above. Note that the determination steps S21 to S25 do not have to be performed in the order of steps S21 to S25, and may be performed in an order different from that shown in FIG.

[0103] <Method of Estimating Fuel Mixture Ratio> Next, a method of estimating the fuel mixture ratio will be described with reference to FIGS. 7 and 8. FIG.

[0104] As shown in Figure 8, the higher the FAME content of a mixed fuel of FAME and diesel, the higher both the dielectric constant and density become. Therefore, by appropriately setting the same threshold values ​​as above for the dielectric constant and density, the FAME content can be estimated.

[0105] 7, the lower the HVO content of a blended fuel of HVO and diesel, the higher both the dielectric constant and the density. Therefore, by appropriately setting the same threshold values ​​as above for the dielectric constant and density, the HVO content can be estimated.

[0106] <Effects> The effects of this embodiment will be described below.

[0107] According to this embodiment, as shown in Fig. 3, the controller 50 estimates the type of fuel based on the physical property values ​​(for example, density alone, dielectric constant alone, or a combination of density and dielectric constant) detected by the fuel property sensor 1. This makes it possible to accurately estimate whether a fuel containing a carbon-neutral fuel has been used. In particular, by estimating the type of fuel based on a combination of density and dielectric constant, it is possible to more accurately estimate whether a fuel containing a carbon-neutral fuel has been used.

[0108] According to this embodiment, the carbon-neutral fuel includes at least one of HVO and FAME. FAME is a common biofuel, and HVO is a high-quality, stable fuel.

[0109] Furthermore, according to this embodiment, the controller 50 estimates the mixture ratio of the fuel based on the physical property values ​​of the fuel (for example, density alone, dielectric constant alone, or a combination of density and dielectric constant), thereby enabling the mixture ratio of the carbon-neutral fuel to be estimated with high accuracy.

[0110] Furthermore, according to this embodiment, the controller 50 calculates the carbon dioxide emission reduction effect of using carbon-neutral fuel from the carbon dioxide reduction rate for each type of carbon-neutral fuel, the mixing ratio for each type of carbon-neutral fuel, and the amount of fuel used by the work machine 10. This makes it possible to know the carbon dioxide emission reduction effect of using carbon-neutral fuel, and to know the load on the environment.

[0111] Furthermore, according to this embodiment, as shown in Figure 2, the controller 50 calculates the amount of fuel used by the work machine 10 based on the amount of fuel stored in the fuel tank 6 detected by the fuel level sensor 7. This makes it possible to calculate the amount of fuel used with high accuracy, and to calculate the effect of reducing carbon dioxide emissions with high accuracy.

[0112] <Additional Notes> The above-described embodiment includes the following technical ideas.

[0113] (Supplementary Note 1) A fuel identification system for a work machine, comprising: a fuel property sensor that detects at least density as a physical property value of a fuel including a carbon-neutral fuel; and a controller that estimates the type of fuel based on the physical property value detected by the fuel property sensor.

[0114] (Supplementary Note 2) A fuel identification system for a work machine, comprising: a fuel property sensor that detects at least the dielectric constant as a physical property value of a fuel including a carbon-neutral fuel; and a controller that estimates the type of fuel based on the physical property value detected by the fuel property sensor.

[0115] (Supplementary Note 3) The fuel identification system for a work machine according to Supplementary Note 1 or Supplementary Note 2, wherein the carbon-neutral fuel includes at least one of HVO and FAME.

[0116] (Supplementary Note 4) The fuel identification system for a work machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the controller estimates a mixture ratio of fuel based on the physical property values ​​of the fuel.

[0117] (Supplementary Note 5) A fuel identification system for a work machine as described in any one of Supplementary Note 1 to Supplementary Note 4, wherein the controller calculates the effect of reducing carbon dioxide emissions by using carbon-neutral fuel from the carbon dioxide reduction rate for each type of carbon-neutral fuel, the mixing ratio for each type of carbon-neutral fuel, and the amount of fuel used by the work machine.

[0118] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0119] 1 fuel property sensor, 2 monitor, 3a, 3b pump, 4a, 4b filter, 5 common rail, 6 fuel tank, 7 fuel level sensor, 10 work machine, 11 main body, 12 work equipment, 13 rotating body, 13a exterior panel, 14 driver's cab, 14S driver's seat, 15 running body, 15Cr track, 15M running motor, 16 boom, 17 arm, 18 bucket, 19a boom cylinder, 19b arm cylinder, 19c bucket cylinder, 20 server, 50 controller, 51 fuel property value acquisition unit, 52 fuel estimation unit, 53 reduction effect calculation unit, 54 output control unit, 55 memory, AT arm top pin, BF boom foot pin, BT boom top pin, RX rotating axis.

Claims

1. A fuel identification system for a work machine comprising: a fuel property sensor that detects at least density as a physical property value of a fuel, including a carbon-neutral fuel; and a controller that estimates the type of fuel based on the physical property value detected by the fuel property sensor.

2. A fuel identification system for a work machine comprising: a fuel property sensor that detects at least the dielectric constant as a physical property value of a fuel including a carbon-neutral fuel; and a controller that estimates the type of fuel based on the physical property value detected by the fuel property sensor.

3. A fuel identification system for a work machine according to claim 1 or 2, wherein the carbon-neutral fuel includes at least one of HVO and FAME.

4. A fuel identification system for a work machine according to claim 1 or 2, wherein the controller estimates a mixture ratio of the fuel based on the physical property values ​​of the fuel.

5. A fuel identification system for a work machine as described in claim 1 or claim 2, wherein the controller calculates the carbon dioxide emission reduction effect of using carbon-neutral fuel from the carbon dioxide reduction rate for each type of carbon-neutral fuel, the mixing ratio for each type of carbon-neutral fuel, and the amount of fuel consumed by the work machine.

6. A fuel identification method for a work machine, comprising the steps of: acquiring at least density as a physical property value of a fuel including a carbon-neutral fuel; and estimating the type of fuel based on the acquired physical property value.

7. A fuel identification method for a work machine, comprising the steps of: acquiring at least a dielectric constant as a physical property value of a fuel including a carbon-neutral fuel; and estimating the type of fuel based on the acquired physical property value.

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