JP2008281486A - Device and method for detecting fuel deterioration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for detecting fuel deterioration that are capable of detecting oxidative fuel degradation and informing a user of the same. <P>SOLUTION: In the device for detecting fuel deterioration, ECU 10 calculates a fuel deterioration index value (oxidative deterioration degree) X of a biofuel, and, if the fuel deterioration index value X exceeds a threshold Xf, it lights a first warning light 21 of an instrument panel 20 and warns an user of the oxidative degradation of the biofuel, and thus it can detect the oxidative degradation of the biofuel and inform the user of the same. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel deterioration detection device and a fuel deterioration detection method, and more particularly to a fuel deterioration detection device and a fuel deterioration detection method capable of detecting the degree of oxidative deterioration of biofuel.

In recent years, biomass raw materials composed of plant resources such as sugarcane, corn, wheat, palm coconut, rapeseed, sunflower seeds, coconut, and soybean are expected to be used as alternative fuels against the background of the past oil crisis. Biomass fuel, which is renewable energy (hereinafter referred to as biofuel), has the effect of suppressing the amount of carbon dioxide (CO ₂ ) generated, and it can effectively use biomass as waste. It is attracting attention as one of the measures. In particular, in the automobile industry, biofuel is expected as an alternative to petroleum fuel (see, for example, Patent Document 1).

  In general, biofuels are liable to be oxidized by oxygen in the air, and there is a problem that they are oxidized and deteriorated with the passage of time. In particular, biofuels such as fatty acid methyl esters (FAME) and methanol made from palm palm, rapeseed, sunflower seeds, coconuts, soybeans, etc. produce fatty acids when oxidation occurs, and are used in vehicle fuel supply systems and engine parts. There is a problem that metal corrosion, clogging, etc. are caused, and vehicle performance, drivability, exhaust performance, etc. are lowered.

JP 2006-144736 A

  However, it is desirable to use such biofuel immediately after production, but it may be stored in a storage tank of a gas station or a vehicle for a long time, and may be oxidized and deteriorated during use. In addition, the oxidative degradation of biofuel is promoted in high seasons and regions. For this reason, in order to avoid using the biofuel which the user deteriorated by oxidation, it is desired to notify the user of the oxidation deterioration of the biofuel.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel deterioration detection device and a fuel deterioration detection method capable of detecting oxidative deterioration of fuel and notifying a user.

  In order to solve the above-described problems and achieve the object, the present invention provides a fuel deterioration detection device for detecting fuel deterioration, a detection means for detecting a degree of oxidation deterioration of the fuel, and a detection means detected by the detection means. And a warning means for warning the oxidation deterioration of the fuel when the oxidation deterioration degree of the fuel exceeds a threshold value.

  According to a preferred aspect of the present invention, it is desirable that the detection means detects the degree of oxidative deterioration of the fuel at predetermined time intervals.

  According to a preferred aspect of the present invention, the warning means informs the deterioration of the fuel when the degree of oxidative deterioration of the fuel detected by the detecting means exceeds a first threshold, and It is desirable to stop the operation of the internal combustion engine when a second threshold value greater than the first threshold value is exceeded.

  According to a preferred aspect of the present invention, it is desirable that the degree of oxidative degradation is an acid value or a peroxide value as an index.

  Moreover, according to a preferable aspect of the present invention, it is desirable that the fuel is a biofuel.

  According to a preferred aspect of the present invention, in the fuel deterioration detection method for detecting fuel deterioration, a detection step for detecting the degree of oxidation deterioration of the fuel, and a degree of oxidation deterioration of the fuel detected in the detection step are provided. A warning step of warning the oxidation deterioration of the fuel when a threshold value is exceeded.

  According to the present invention, in the fuel deterioration detection device for detecting fuel deterioration, the detection means for detecting the degree of oxidative deterioration of the fuel, and the degree of oxidative deterioration of the fuel detected by the detection means exceeds a threshold value And a warning means for warning the oxidation deterioration of the fuel, it is possible to provide a fuel deterioration detection device capable of detecting the oxidation deterioration of the fuel and notifying the user. There is an effect.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. In the following embodiments, a case where the fuel deterioration detection device according to the present invention is applied to a vehicle will be described.

  FIG. 1 is a diagram showing a schematic configuration of a fuel deterioration detection apparatus according to Embodiment 1 of the present invention. As shown in the figure, the fuel deterioration detection device is roughly divided into an ECU 10, an instrument panel 20, a fuel tank 30, a titrant tank 40, a solvent tank 50, a mixing tank 60, a waste tank 70, a deterioration determination sensor 80, an elapsed time. It consists of a counter 90 and the like.

  The fuel tank 30 is for storing the fuel 31. The fuel 31 is a biofuel (for example, fatty acid methyl ester, methanol or the like) alone, or a biofuel mixed fuel (for example, biofuel mixed light oil, biofuel mixed gasoline or the like). The fuel tank 30 is provided with a level sensor 32 for detecting the liquid level of the fuel 31 and a discharge port 37 for discharging the fuel 31 to the outside. The detection result of the level sensor 32 is output to the ECU 10. In addition, the fuel tank 30 supplies the fuel 31 in the fuel tank 30 to the mixing tank 60 via the passage 35 and the fuel 31 to the engine (not shown) via the passage 36. For this purpose, an engine supply pump 34 is connected. The opening and closing operations of the fuel pump 33 and the engine supply pump 34 are controlled by the ECU 10.

  The titrant tank 40 stores a titrant 41 used in the fuel deterioration determination process. The titrant tank 40 is provided with a level sensor 45 that detects the liquid level of the titrant 41, and the detection result of the level sensor 45 is output to the ECU 10. Further, a titration pump 42 for supplying the titrant 41 to the mixing tank 60 through the passage 43 is connected to the titrant tank 40. The opening / closing operation of the titration pump 42 is controlled by the ECU 10. The titration pump 42 is connected to a pump operation time counter 44 that measures the operation time of the titration pump 42, and the measured operation time of the titration pump 42 is output to the ECU 10.

  The solvent tank 50 is for storing the solvent 51 used in the fuel deterioration determination process. The solvent tank 50 is provided with a level sensor 52 that detects the liquid level of the solvent 51, and the detection result of the level sensor 52 is output to the ECU 10. The solvent tank 50 is connected to a solvent pump 53 for supplying the solvent 51 to the mixing tank 60 via the passage 54. The opening / closing operation of the solvent pump 53 is controlled by the ECU 10.

  The mixing tank 60 is used when the PH of the fuel 31 is measured in the fuel deterioration determination process, and temporarily stores the mixed liquid 61 of the fuel 31, the solvent 51, and the titrant 41. In the mixing tank 60, a level sensor 62 for detecting the liquid level of the mixed liquid 61, a stirrer 63 for stirring the mixed liquid 61, an electrode 81 of the deterioration determination sensor 80, and the mixed liquid 61 through the passage 65 are provided. And a discharge valve 64 for discharging to the waste liquid tank 70. The detection result of the level sensor 62 is output to the ECU 10, and the operation of the stirrer 63 and the opening / closing operation of the discharge valve 64 are controlled by the ECU 10.

  The waste liquid tank 70 stores the mixed liquid 61 in the mixing tank 60 as a waste liquid 71. The waste liquid tank 70 is provided with a level sensor 72 for detecting the liquid level of the waste liquid 71 and a discharge port 73 for discharging the waste liquid 71 to the outside. The detection result of the level sensor 72 is output to the ECU 10.

  The deterioration determination sensor 80 measures the PH of the fuel 31 in the mixing tank 60 with the electrode 81 and outputs a sensor instruction voltage V corresponding to the PH to the ECU 10.

  The instrument panel 20 includes a first warning light 21, a second warning light 22, a speedometer, and the like. The elapsed time counter 90 counts the elapsed time and outputs the elapsed time count value T to the ECU 10. The elapsed time counter 90 counts the elapsed time even when the IG is OFF.

  Various controls of the fuel deterioration detection device 1 are performed by the ECU 10. The ECU 10 includes a CPU that executes various arithmetic processes related to the control of the fuel deterioration detection device 1, a ROM that stores control programs and data necessary for the control, a RAM that temporarily stores CPU calculation results, and the like. An input / output port for inputting / outputting a signal between them is provided.

  Level sensors 32, 45, 52, 62, 72, a deterioration determination sensor 80, an elapsed time counter 90, and the like are connected to the input port of the ECU 10. Further, driving circuits such as the instrument panel 20, the fuel pump 33, the engine supply pump 34, the titration pump 42, the solvent pump 53, the stirrer 63, and the discharge valve 64 are connected to the output port of the ECU 10.

  The ECU 10 receives a detection signal from each of the sensors and outputs a command signal to the drive circuit of each device connected to the output port. ECU10 performs the fuel deterioration detection process mentioned later by running the control program stored in ROM by CPU.

  A fuel deterioration detection method of the fuel deterioration detection apparatus 1 having the above configuration will be described. As the fuel deterioration index value (oxidation deterioration degree), for example, an acid value, a peroxide value, or the like can be used. Here, an example in the case of measuring the acid value will be described. Below, the case where an acid value is measured as a fuel deterioration index value by the method prescribed | regulated by JIS specification "JIS K0070" is demonstrated.

  A diethyl ether / ethanol mixed solution is used as the solvent 51, a potassium hydroxide ethanol solution is used as the titrant 41, and a PH measurement electrode is used as the electrode 81 of the measurement determination sensor 80.

  First, the fuel pump 33 and the solvent pump 53 are operated at a specified flow rate for a specified time, and a specified amount of fuel 31 (for example, 20 g) and a specified amount of solvent 51 (for example, 125 mL) are supplied to the mixing tank 60 and mixed. The liquid 61 is mixed with a stirrer 63. Next, while the mixed solution 61 is being stirred with the stirrer 63, the titration pump 42 is operated to drop the titrant 41 into the mixed solution 61 in the mixing tank 60. In this case, the titration amount per unit operating time of the titration pump 42 is set to be the same. When the electrode 81 of the deterioration determination sensor 80 detects a potential (target potential Vt) corresponding to the target PH, the titration pump 42 is stopped and the titration of the titrant 41 is finished. ECU10 calculates an acid value based on following Formula (1). In addition, the dripping amount of a blank shall be known beforehand.

Acid value (mgKOH / g) = (D−B) × K × F × M / S (1)
Here, D: dripping amount (mL)
B: Blank (Example: 0.085 mL)
K: Molecular weight of KOH (example: 56.1)
F: Factor of titrant (example: 1.000)
M: molar concentration of titrant (example: 0.1 mol / L)
S: Sample collection amount (example: 20 g)

  In addition, when using a peroxide value as a fuel deterioration index value, the measuring method prescribed | regulated by Petroleum Institute standard "JPI-5S-46-96" can be used, for example.

  2 and 3 are flowcharts for explaining the fuel deterioration detection process executed by the ECU 10 having the above-described configuration, FIG. 2 is a flowchart for explaining the entire process of the fuel deterioration detection process, and FIG. It is a flowchart for demonstrating the detailed process content of the fuel deterioration determination process (step S9) of a fuel deterioration detection process. The ECU 10 executes the fuel deterioration detection process at a predetermined cycle while the IG is turned on. When the IG is turned off, the fuel deterioration detection process is interrupted, and when the IG is turned on again, the fuel detection process is restarted from the point where it was interrupted.

  In FIG. 2, the ECU 10 first determines whether or not the elapsed time count value T input from the elapsed time counter 90 is less than the threshold value Tf (step S1). When the elapsed time count value T <the threshold value Tf (“Yes” in step S1), the ECU 10 operates the fuel pump 33 and the solvent pump 53 at a specified flow rate for a specified time, and from the fuel tank 30 and the solvent tank 50, A prescribed amount of fuel 31 and solvent 51 are supplied to the mixing tank 60 (step S2).

  The ECU 10 operates the fuel pump 33 and the solvent pump 53 at a specified flow rate for a specified time, then stops the fuel pump 33 and the solvent pump 53, operates the stirrer 63 in the mixing tank 60, and removes the fuel 31 and the solvent 51. Stirring of the mixed solution 61 is started (step S3).

  The ECU 10 operates the titration pump 42 in a state where the mixed liquid 61 is stirred by the stirrer 63 to drop the titrant 41 from the titrant tank 40 and activate the deterioration determination sensor 80 (step S4). Thereby, the sensor instruction potential V detected by the electrode 81 of the deterioration determination sensor 80 is output to the ECU 10.

  The ECU 10 determines whether or not the sensor instruction potential V = target potential Vt (step S5). If the sensor instruction potential V = target potential Vt (“Yes” in step S5), the titrant liquid pump 42 is stopped, the dropping of the titrant 41 is stopped, the deterioration determination sensor 80 is stopped, and the titration is finished (step S6). Further, the ECU 10 opens the discharge valve 64 of the mixing tank 60 and sends the mixed liquid 61 to the waste liquid tank 70 (step S7). After the discharge of the mixed liquid 61 is completed, the discharge valve 64 is closed. Thereafter, the ECU 10 resets the elapsed time counter value T of the elapsed time counter 90 (step S8). Thereby, the elapsed time counter 90 newly starts counting the elapsed time. Thereafter, the ECU 10 executes a fuel deterioration determination process (step S9).

  Next, with reference to FIG. 3, the detailed processing content of the fuel deterioration determination processing in step S9 will be described. In this fuel deterioration determination process, when the fuel deterioration index value exceeds the threshold value, the warning lamp 21 of the instrument panel 20 is turned on to warn the user (driver) of the oxidative deterioration of the fuel.

  In FIG. 3, first, the ECU 10 calculates the fuel deterioration index value X according to the above equation (1) (step S21), and determines whether or not the fuel deterioration index value X> the threshold value Xf (step S22). When the fuel deterioration index value X> the threshold value Xf is not satisfied (“No” in step S22), the ECU 10 determines whether or not the first warning lamp 21 of the instrument panel 20 is turned on (step S23). If the first warning lamp 21 is not lit (“No” in step S23), the flow is terminated, while if the first warning lamp 21 is lit (“Yes” in step S23). ”), After the first warning lamp 21 is turned off (step S24), the flow ends.

  On the other hand, in step S22, when the fuel deterioration index value X> threshold value Xf (“Yes” in step S22), the ECU 10 turns on the first warning lamp 21 of the instrument panel 20 and the fuel is deteriorated to the user. A warning is given (step S25). The user sees that the first warning lamp 21 is lit and replenishes or replaces the fuel. When the ECU 10 detects the change in the liquid level of the fuel 31 with the level sensor 32 of the fuel tank 30 and detects replenishment or replacement of the fuel 31 (“Yes” in step S26), the ECU 10 returns to step S2 in FIG. The fuel deterioration index value X is calculated again for the replenished or replaced fuel 31 (steps S2 to S9, S21), and when the fuel deterioration index value X> threshold value Xf is not satisfied (“No” in step S22). The first warning lamp 21 that is turned on ("Yes" in step S23) is turned off (step S24).

  In step S26, the ECU 10 detects the change in the liquid level of the fuel 31 by the level sensor 32 of the fuel tank 30 and detects the replenishment or replacement of the fuel 31, but the fuel reset is performed in the instrument panel 20. A button may be provided, and the ECU 10 may determine that the fuel 31 has been replenished or replaced when the user presses the fuel reset button.

  As described above, according to the first embodiment, the ECU 10 calculates the fuel deterioration index value (oxidation deterioration degree) X of the biofuel, and when the fuel deterioration index value X exceeds the threshold value Xf, the instrument panel 20 Since the first warning lamp 21 is turned on to warn of the oxidative deterioration of the biofuel, it is possible to detect the oxidative deterioration of the biofuel and notify the user.

  Further, according to the first embodiment, the ECU 10 detects the fuel deterioration index value (oxidation deterioration degree) X of the biofuel at the predetermined time interval Tf, and thus determines the oxidative deterioration of the biofuel at the predetermined time interval. It becomes possible.

  Further, according to the first embodiment, since the acid value or the peroxide value is used as the fuel deterioration index value (oxidation deterioration degree), the fuel deterioration index value (oxidation deterioration degree) with high accuracy by a simple measurement method. ) Can be calculated.

  FIG. 4 is a flowchart for explaining the fuel deterioration determination process (step S9 in FIG. 2) according to the second embodiment. In the second embodiment, the threshold value for determining the deterioration of the fuel 31 is set in two stages (first threshold value Xf1 <second threshold value (limit value) Xf2), and the fuel deterioration index value X exceeds the first threshold value Xf1. In such a case, the user is warned to change the fuel, and further, when the second threshold value (limit value) Xf2 is exceeded, operating with this oxidized and deteriorated fuel causes troubles in hardware such as the engine. Because there is a possibility, stop the engine.

  In FIG. 4, first, the ECU 10 calculates the fuel deterioration index value X according to the above equation (1) (step S31), and determines whether or not the fuel deterioration index value X> the second threshold value (limit value) Xf2. Determination is made (step S32). If the fuel deterioration index value X> the second threshold value (limit value) Xf2 is not satisfied (“No” in step S32), the ECU 10 proceeds to step S33, while the fuel deterioration index value X> second threshold value (limit) When the value is Xf2 ("Yes" in step S32), the second warning lamp 22 of the instrument panel 20 is turned on (step S38), and then the engine is stopped (step S39). As a result, even when the fuel 31 that has deteriorated due to oxidation such that the fuel deterioration index value X exceeds the second threshold value (limit value) Xf2 is supplied, the engine is quickly stopped to avoid engine trouble or the like. Can do.

  In step S33, the ECU 10 determines whether or not the fuel deterioration index value X> the first threshold value Xf1. When the fuel deterioration index value X> the first threshold value Xf1 is not satisfied (“No” in step S33), the ECU 10 determines whether or not the first warning lamp 21 of the instrument panel 20 is turned on (step S34). . If the first warning lamp 21 is not turned on (“No” in step S34), the flow is terminated, while if the first warning lamp 21 is turned on (“Yes” in step S34). ”), After the first warning lamp 21 is turned off (step S35), the flow ends.

  On the other hand, in step S33, when the fuel deterioration index value X> the first threshold value Xf1 (“Yes” in step S33), the ECU 10 turns on the first warning lamp 21 of the instrument panel 20 and informs the user. A warning is given that the fuel is oxidatively deteriorated, and the fuel 31 is urged to be replaced (step S36). Thereafter, the ECU 10 determines whether or not the elapsed time count value T> the threshold value Tf2 (step S37). Here, threshold value Tf2 <threshold value Tf is set, and after the first-stage warning (the first warning lamp 21 is turned on), the measurement frequency of the fuel deterioration index value X is increased more than usual.

  If the elapsed time count value T> the threshold value Tf2 (“Yes” in step S37), the ECU 10 returns to step S2 in FIG. 2 to calculate the fuel deterioration index value X again (steps S2 to S9, S31). Here, when the fuel 31 is replaced with the fuel 31 having no oxidative deterioration, the fuel deterioration index value X> the first threshold value Xf1 is not satisfied (“No” in Step S33), and the first warning lamp 21 that is lit (Step S33). The light is turned off (Step S35). On the other hand, if the fuel 31 is not replaced and the oxidative deterioration of the fuel 31 further progresses, and the fuel deterioration index value X> the second threshold value (limit value) Xf2 (“Yes” in step S32), the instrument panel 20 After the second warning lamp 22 is turned on (step S35), the engine is stopped (step S39).

  As described above, according to the second embodiment, the ECU 10 determines that the first warning lamp 21 of the instrument panel 20 when the fuel deterioration index value X (oxidation deterioration degree) of the fuel 31 exceeds the first threshold value Xf1. Is turned on to prompt the user to change the fuel, and when the second threshold value Xf2 larger than the first threshold value Xf1 is exceeded, the operation of the engine is stopped, so depending on the degree of oxidative deterioration of the fuel It becomes possible to give a warning to the user step by step.

  In the above-described embodiment, the case where the fuel deterioration detection device according to the present invention is mounted on a vehicle has been described. However, the present invention is not limited to this, and is installed in a gas station, a fuel storage, or the like. It may be. Moreover, although biofuel was demonstrated as a fuel, this invention is not restricted to this, It is possible to apply also to other fuels, if it is a fuel which is easy to oxidatively deteriorate. Further, the warning lamp is turned on when warning of fuel deterioration, but the present invention is not limited to this, and a warning screen display, voice warning, or the like may be performed.

  INDUSTRIAL APPLICABILITY The fuel deterioration detection device and the fuel deterioration detection method according to the present invention can be widely used when detecting oxidative deterioration of fuel. be able to.

It is a figure which shows schematic structure of the fuel deterioration detection apparatus which concerns on the Example of this invention. It is a flowchart for demonstrating the whole process of a fuel deterioration detection process. FIG. 3 is a flowchart for explaining a first embodiment of a fuel deterioration determination process of the fuel deterioration detection process of FIG. 2; FIG. 6 is a flowchart for explaining a second embodiment of the fuel deterioration determination process of the fuel deterioration detection process of FIG. 2;

Explanation of symbols

1 Fuel Degradation Detection Device 10 ECU
20 instrument panel 30 fuel tank 31 fuel 32 level sensor 33 fuel pump 34 engine supply pump 35, 36 passage 37 outlet 40 titrant liquid tank 41 titrant liquid 42 titration pump 43 passage 44 pump operating time counter 45 level sensor 50 solvent tank 51 solvent 52 level sensor 53 solvent pump 54 passage 60 mixing tank 61 liquid mixture 62 level sensor 63 stirrer 64 discharge valve 65 passage 70 waste liquid tank 71 waste liquid 72 level sensor 73 outlet 80 deterioration judgment sensor 81 electrode 90 elapsed time counter

Claims (6)

In a fuel deterioration detection device that detects fuel deterioration,
Detecting means for detecting the degree of oxidative deterioration of the fuel;
Warning means for warning the oxidation deterioration of the fuel when the degree of oxidation deterioration of the fuel detected by the detection means exceeds a threshold;
A fuel deterioration detection device comprising:   2. The fuel deterioration detection apparatus according to claim 1, wherein the detection means detects the degree of oxidation deterioration of the fuel at predetermined time intervals.   The warning means warns the oxidation deterioration of the fuel when the degree of oxidation deterioration of the fuel detected by the detection means exceeds a first threshold, and further, a second higher than the first threshold. The fuel deterioration detection device according to any one of claims 1 to 3, wherein when the threshold value is exceeded, the operation of the internal combustion engine is stopped.   The fuel deterioration detection device according to any one of claims 1 to 3, wherein the oxidation deterioration degree uses an acid value or a peroxide value as an index.   The fuel deterioration detection device according to claim 1, wherein the fuel is biofuel. In a fuel deterioration detection method for detecting fuel deterioration,
A detection step of detecting the degree of oxidative deterioration of the fuel;
A warning step of warning the oxidation deterioration of the fuel when the degree of oxidation deterioration of the fuel detected in the detection step exceeds a threshold;
A fuel deterioration detection method comprising:

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