Fuel reforming device

Abstract

A fuel reforming device includes: first and second storage sections that store fuel for an internal combustion engine; a reformer that reforms the fuel supplied from the first storage section according to temperature; a temperature adjustment section that adjusts the temperature of the reformer; a first flow path that guides the fuel reformed in the reformer to a gas phase of the first storage section; a second flow path that guides the fuel reformed in the reformer to the second storage section; a switching valve that opens either of the first and second flow paths; an outside air temperature detection section that detects an outside air temperature; and a controller that controls the switching valve and the temperature adjustment section according to the detected outside air temperature. The controller controls the switching valve to open the first flow path when the detected outside air temperature exceeds a prescribed temperature at the time of start of the internal combustion engine, controls the switching valve to open the second flow path when the detected outside air temperature is below the prescribed temperature at the time of start of the internal combustion engine, and controls the temperature adjustment section according to the outside air temperature detected by the outside air temperature detection section.

Description

Technical Field

[0001] This invention relates to a fuel modification device for modifying fuel in internal combustion engines. Background Technology

[0002] Previously known apparatuses modified ethanol fuel in internal combustion engines to DEE (diethyl ether) (see, for example, Patent Document 1). In the apparatus described in Patent Document 1, MFI-type zeolite with a silica / alumina ratio of 20 or more and 45 or less, and mordenite with a silica / alumina ratio of 18 or more and 35 or less are used as catalysts to modify ethanol to DEE, and fuel containing the modified DEE is supplied when the internal combustion engine is started.

[0003] From the perspective of mitigating climate change or reducing its impact, it is preferable to replace existing fossil fuels with high carbon intensity, such as bioethanol, to reduce carbon emissions. However, such new fuels differ from existing fuels in properties such as volatility. From the perspective of contributing to the development of sustainable delivery systems, when applying such new fuels to existing internal combustion engines, it is preferable to not only perform modifications necessary to ensure combustion performance but also consider safety and efficiency in the storage, modification, and supply to the internal combustion engine. However, the device described in Patent Document 1 does not adequately consider this aspect.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent document 1: Japanese Patent Application Publication No. 2008-144730 (JP2008-144730A). Summary of the Invention

[0007] The fuel modification apparatus of this invention comprises: a first storage section and a second storage section for storing fuel from an internal combustion engine; a modifier for modifying fuel supplied from the first storage section according to temperature; a temperature adjustment section for adjusting the temperature of the modifier; a first flow path for guiding the fuel modified by the modifier to the gas phase of the first storage section; a second flow path for guiding the fuel modified by the modifier to the second storage section; a switching valve for opening either the first flow path or the second flow path; an external temperature detection section for detecting the external temperature; and a controller for controlling the switching valve and the temperature adjustment section according to the external temperature detected by the external temperature detection section. When the internal combustion engine is started, the controller controls the switching valve to open the first flow path when the external temperature detected by the external temperature detection section exceeds a predetermined temperature; when the internal combustion engine is started, the controller controls the switching valve to open the second flow path when the external temperature detected by the external temperature detection section is below the predetermined temperature; and controls the temperature adjustment section according to the external temperature detected by the external temperature detection section. Attached Figure Description

[0008] The objectives, features, and advantages of the present invention are further illustrated by the following description of embodiments in conjunction with the accompanying drawings.

[0009] Figure 1 This is a block diagram schematically illustrating an example of the overall configuration of a fuel modification device according to an embodiment of the present invention.

[0010] Figure 2 This is a block diagram schematically illustrating an example of the main components of a fuel modification apparatus according to an embodiment of the present invention.

[0011] Figure 3 This is a graph used to illustrate the relationship between the external temperature and the target DEE concentration when an internal combustion engine starts.

[0012] Figure 4 This is a graph used to illustrate the relationship between modification temperature and DEE concentration.

[0013] Figure 5 This is a flowchart illustrating an example of a process performed by a fuel modification apparatus according to an embodiment of the present invention. Detailed Implementation

[0014] The following is for reference Figures 1 to 5 Embodiments of the present invention will be described. The fuel modification apparatus of the present invention modifies the fuel supplied to the internal combustion engine as needed.

[0015] Because of greenhouse gases in the atmosphere, the Earth's average temperature remains at a warm level suitable for life. Specifically, greenhouse gases absorb some of the heat radiated from the Earth's surface, heated by sunlight, into space, and then radiate it back to the Earth's surface, thus keeping the atmosphere warm. When the concentration of such greenhouse gases in the atmosphere increases, the Earth's average temperature rises (global greenhouse effect).

[0016] The concentration of carbon dioxide, a major contributor to global warming among greenhouse gases, in the atmosphere is determined by the balance between carbon fixed in the ground and underground as plants and fossil fuels and carbon existing in the atmosphere as carbon dioxide. For example, when carbon dioxide is absorbed from the atmosphere through photosynthesis during plant growth, the atmospheric carbon dioxide concentration decreases; conversely, when carbon dioxide is released into the atmosphere through the combustion of fossil fuels, the atmospheric carbon dioxide concentration increases. To curb global warming, renewable fuels such as bioethanol need to replace fossil fuels to reduce carbon emissions.

[0017] Bioethanol fuel absorbs CO2 from the atmosphere during the cultivation of crops (plants) such as corn. The carbon component in bioethanol fuel originates from the CO2 absorbed from the atmosphere during the growth of the raw material crops. Therefore, even if it is released back into the atmosphere as CO2 through combustion, it will not change the balance (carbon neutralization) between the fixed carbon and the carbon already present in the atmosphere.

[0018] However, because ethanol has a lower vapor pressure at low temperatures compared to gasoline, it is difficult to ensure combustion performance during cold starts if it is used directly as fuel in internal combustion engines. In this regard, cold-start performance can be improved by modifying ethanol into DEE (diethyl ether), which has a sufficiently high vapor pressure at low temperatures, before supplying it to the internal combustion engine.

[0019] On the other hand, DEE has a low boiling point (DEE boiling point: approximately 35°C, ethanol boiling point: approximately 78°C) and is easily vaporized. Therefore, when the DEE concentration increases due to excessive modification, the vapor barrier of DEE may actually reduce combustion performance. In addition, if the consumption of DEE obtained by modifying ethanol exceeds the necessary level, the overall efficiency of the device will decrease.

[0020] Furthermore, compared to gasoline, ethanol has a lower vapor pressure in the temperature range typically used in internal combustion engines (approximately below 100°C). Therefore, even with gasoline, ethanol would enter the explosive range in the absence of sufficient oxygen in the fuel tank. Consequently, it is more difficult to keep the fuel tank outside the explosive range with ethanol compared to gasoline.

[0021] Therefore, in this embodiment, the fuel modification device is configured as follows so that by performing appropriate modification at low temperatures, the fuel tank can be kept outside the explosion range above a certain temperature, thereby ensuring the combustibility, safety and efficiency of the modified fuel.

[0022] Figure 1 This is a block diagram schematically illustrating an example of the overall structure of a fuel modification device 100 according to an embodiment of the present invention. Figure 1 As shown, the fuel modification device 100 includes: a fuel tank 1 storing fuel primarily composed of ethanol; a modifier 2 modifying the fuel; a modified fuel tank 3 storing the modified fuel; and a mixer 4 mixing the modified fuel and air to generate a mixture. The mixture generated by the mixer 4 is supplied to the combustion chamber of an internal combustion engine 5. The mixer 4 can also be configured as part of a direct injection internal combustion engine 5 that directly injects fuel into the combustion chamber.

[0023] The liquid phase of fuel tank 1 and the inlet of the modifier 2 are connected via piping 6. An electric pump 7, installed on piping 6, supplies fuel stored in fuel tank 1 to the modifier 2 via piping 6. The operation of the electric pump 7 is controlled by controller 20. Figure 2 )control.

[0024] A suitable catalyst is filled into the modifier 2 to promote the intermolecular dehydration reaction (endothermic reaction) of the following formula. A heater 8 is provided in the modifier 2 to adjust the temperature of the modifier 2, modifying the ethanol contained in the fuel supplied from the fuel tank 1 to DEE at a modification rate corresponding to the temperature. The modified fuel contains reacted DEE and unreacted ethanol in a proportion corresponding to the modification rate. It should be noted that when the modification temperature is above 100°C, the modified fuel becomes a gas. The operation of the heater 8 is controlled by a controller 20. Figure 2 )control.

[0025] 2C2H5OH(l)→C2H5OC2H5(g)+H2O(g)

[0026] The outlet of the modifier 2 is connected to the gas phase of the fuel tank 1 via pipe 9, and the outlet of the modifier 2 is connected to the modified fuel tank 3 via pipe 10. The modified fuel that has been modified in the modifier 2 is supplied to the gas phase of the fuel tank 1 via the first flow path through pipe 9, and to the modified fuel tank 3 via the second flow path through pipe 10.

[0027] The gas phase of fuel tank 1 is also connected to an adsorption tank 12 filled with suitable adsorption material via a pipe 11 equipped with a check valve 11a. When the modified fuel, which has been modified in the modifier 2, flows into the gas phase of fuel tank 1 via pipe 9 (first flow path), the air present in the gas phase of fuel tank 1 due to mixing during fuel supply is purged and flows out via pipe 11. The fuel components flowing out with the air are adsorbed and recovered in the adsorption tank 12, and the air after the fuel components have been recovered is opened to the atmosphere. A concentration sensor 1a is installed in fuel tank 1 to detect the DEE concentration (partial pressure) of the gas phase of fuel tank 1. A signal showing the detection result of the concentration sensor 1a is sent to the controller 20. Figure 2 ).

[0028] A condenser 13 is installed in the piping 10 (second flow path) between the modifier 2 and the modified combustion chamber 3. The modified gaseous fuel is condensed in the condenser 13 and stored as a liquid in the modified combustion chamber 3. A concentration sensor 3a is installed in the modified combustion chamber 3 to detect the DEE concentration (modified DEE concentration) of the modified fuel stored as a liquid in the modified combustion chamber 3. A signal showing the detection result of the concentration sensor 3a is sent to the controller 20. Figure 2 ).

[0029] The liquid phase of fuel tank 1 is also connected to mixer 4 via pipe 14. The unmodified fuel stored in fuel tank 1 is supplied to mixer 4 via electric pump 15 installed in pipe 14. The liquid phase of modified combustion chamber 3 is connected to mixer 4 via pipe 16. The modified fuel stored in modified combustion chamber 3 is supplied to mixer 4 via electric pump 17 installed in pipe 16. The operation of electric pumps 15 and 17 is controlled by controller 20. Figure 2 )control.

[0030] A concentration sensor 4a is installed in mixer 4 to detect the concentrations of ethanol and DEE in the mixed gas generated by mixer 4. A signal indicating the detection result of concentration sensor 4a is sent to controller 20. Figure 2 ).

[0031] A switching valve 18 is provided at the outlet of the modifier 2. This switching valve 18 switches between a first flow path through pipe 9 and a second flow path through pipe 10. The switching valve 18 can not only open either the first or second flow path, but also close both the first and second flow paths. The switching valve 18 is configured as a solenoid valve, and its operation is controlled by a controller 20. Figure 2 )control.

[0032] Figure 2 This is a block diagram schematically illustrating an example of the main components of a fuel modification device 100 according to an embodiment of the present invention. Figure 2 As shown, the fuel modification device 100, in addition to Figure 1 In addition to the components shown, there is an external temperature sensor 19 for detecting the external temperature and a controller 20. A signal showing the detection result of the external temperature sensor 19 is sent to the controller 20. The controller 20 is connected to concentration sensors 1a, 3a, 4a, external temperature sensor 19, electric pumps 7, 15, 17, heater 8, and switching valve 18.

[0033] The controller 20 is composed of an electronic control unit (ECU). More specifically, the controller 20 is configured as a computer having a processing unit 21 such as a CPU (central processing unit), a storage unit 22 such as ROM (read-only memory) and RAM (random access memory), and other peripheral circuits not shown, such as I / O interfaces. The controller 20 may also be configured as part of an engine control ECU that controls the operation of the internal combustion engine 5.

[0034] Figure 3 This is a graph illustrating the relationship between the external temperature during the start-up of internal combustion engine 5 and the target DEE concentration, showing the target value of the modified DEE concentration in the low-temperature region where internal combustion engine 5 is intended to be used. Figure 3As shown, for example, the target DEE concentration at an external air temperature of -12°C is set to 10 [mol%]. Such characteristics are predetermined and stored in the storage unit 22 of the controller 20.

[0035] Figure 4 This graph illustrates the relationship between modification temperature and DEE concentration, showing experimental results of modified DEE concentration after the modification reaction was carried out at varying modification temperatures. Furthermore, the catalysts used to fill the modifier 2 include Amberlyst (Rohm and Haas) (registered trademark), H-mordenite with a silica / alumina ratio of 18, H-ZSM-5 zeolite with a silica / alumina ratio of 24, and H-ZSM-5 zeolite with a silica / alumina ratio of 40. These are all H-type solid acid catalysts that convert the exchange groups to hydrogen ions.

[0036] like Figure 4 As shown, for example, the modification temperature required to achieve a target DEE concentration of 10 [mol%] at an external temperature of -12°C is approximately 145°C in the case of mordenite and 158°C in the case of Amberlyst (Rohm and Haas) (registered trademark). This characteristic is determined in advance by experiment based on the type of catalyst filled in the modifier 2 and is stored in the storage section 22 of the controller 20.

[0037] Here, in order to investigate suitable catalyst types, a comparative experiment on the amount of acidic sites on the surface of catalysts using the pyridine adsorption method, conducted by the inventors, is described. Comparative experiments were performed on catalyst samples (i) to (vi) below. In the comparative experiments, infrared diffusion reflectance measurements were performed on each catalyst sample adsorbed with pyridine, and the measurement results were compared to compare the amount of Brønsted and Lewis acidic sites on the surface of each catalyst sample.

[0038] (i) H-ZSM-5 zeolite with a silica / alumina ratio of 40

[0039] (ii) Activated alumina

[0040] (iii) H-mordenite with a silica / alumina ratio of 18

[0041] (iv) H-ZSM-5 zeolite with a silica / alumina ratio of 24

[0042] (v) Zirconium oxide sulfate

[0043] (vi)H-Silky Zeolite (W)

[0044] The results of the comparative tests showed that the amount of Brønsted acidic sites increased in the order of (iii)>(iv)>(i)>(v)>(vi)>(ii), with H-mordenite having the highest amount at a silica / alumina ratio of 18, followed by H-ZSM-5 zeolite with a silica / alumina ratio of 24. Additionally, activated alumina remained below the detection limit. The amount of Lewis acidic sites increased in the order of (ii)>>(v)>(iv)>(iii)>(i)>(vi), with activated alumina having the highest amount, and H-mordenite (W) remaining below the detection limit.

[0045] like Figure 4 The experimental results show that H-mordenite with a silica / alumina ratio of 18 and H-ZSM-5 zeolite with a silica / alumina ratio of 24 achieve higher modification rates (DEE concentrations) at lower modification temperatures. Therefore, considering the comparative experimental results on the amount of acidic sites on the catalyst surface, it is preferable to use a catalyst with more Brønsted acidic sites than H-ZSM-5 zeolite with a silica / alumina ratio of 24 as the type of catalyst to fill the modifier 2.

[0046] When the external temperature detected by the external temperature sensor 19 is below a specified temperature, the processing unit 21 of the controller 20 controls the switching valve 18 to open the passage. Figure 1 The second flow path of piping 10. The specified temperature is... Figure 3 The target DEE concentration shown is 0 [mol%] at a temperature, for example, 14°C. Additionally, refer to the storage unit 22... Figure 3 The target DEE concentration is determined based on the external temperature detected by the external temperature sensor 19, referring to the characteristics of the external temperature sensor 19. Figure 4 The characteristics of the material determine the modification temperature required to achieve the target DEE concentration, and the heater 8 is controlled according to the modification temperature. Therefore, the modification rate can be appropriately adjusted, thus preventing the generation of excess DEE and reliably preventing DEE vapor lock.

[0047] When the external temperature detected by the external temperature sensor 19 exceeds the specified temperature, the processing unit 21 of the controller 20 controls the switching valve 18 to open the passage. Figure 1 The first flow path of the piping 9. Thus, the modified fuel flows into the gas phase of the fuel tank 1, and the air mixed in during fuel supply is swept away from the gas phase of the fuel tank 1 to the outside.

[0048] Subsequently, the processing unit 21 of the controller 20 controls the switching valve 18 to close the first flow path based on the condition that the DEE concentration detected by the concentration sensor 1a is above the upper explosive limit (48 [vol%]). That is, the modified fuel is allowed to flow in until the DEE concentration in the gas phase of the fuel tank 1 exceeds the upper explosive limit, and the air is purged. As a result, the concentration of combustible gas in the gas phase of the fuel tank 1 is maintained outside the explosive range, reliably preventing the reaction between the vaporized ethanol and oxygen (air) in the fuel tank 1.

[0049] The processing unit 21 of the controller 20 controls the mixer 4 (electric pumps 7, 15, 17) independently of the external temperature, ensuring that the ethanol and DEE concentrations detected by the concentration sensor 4a are within the explosive range. More specifically, it controls the electric pumps 7, 15, 17 that supply fuel to the mixer 4, ensuring that the ethanol and DEE concentrations detected by the concentration sensor 4a satisfy the following formula. In this way, by ensuring that the concentration of combustible gases in the mixture supplied to the internal combustion engine 5 is within the explosive range, the combustion performance of the internal combustion engine 5 can be ensured.

[0050] Ethanol concentration / lower explosive limit of ethanol + DEE concentration / lower explosive limit of DEE ≥ 1.

[0051] Figure 5 This is a flowchart illustrating an example of the processing performed by the fuel modification apparatus 100 according to an embodiment of the present invention, showing an example of the processing performed by the processing unit 21 of the controller 20. Figure 5 The processing begins, for example, when controller 20 starts.

[0052] like Figure 5 As shown, in step S1, it is first determined whether the internal combustion engine 5 is starting. When step S1 is negative (S1: No), the process proceeds to step S2, where the switching valve 18 is controlled to close both the first and second flow paths, thus ending the process.

[0053] When step S1 is affirmative (S1: Yes), proceed to step S3 to determine whether the external temperature detected by external temperature sensor 19 exceeds the specified temperature. When step S3 is affirmative (S3: Yes), proceed to step S4, control switching valve 18 to open the first flow path, and proceed to step S5 to determine whether the DEE concentration of the gas phase detected by concentration sensor 1a is above the upper explosive limit. Repeat step S5 until it is affirmative. When step S5 is affirmative (S5: Yes), proceed to step S2, control switching valve 18 to close both the first and second flow paths, and end the process.

[0054] When step S3 is negative (S3: No), proceed to step S6, control the switching valve 18 to open the second flow path, and proceed to step S7. In step S7, refer to the data stored in the storage unit 22. Figure 3Based on the characteristics of the external temperature detected by the external temperature sensor 19, the target DEE concentration after modification is determined, and the process proceeds to step S8. In step S8, the value stored in the storage unit 22 is referenced. Figure 4 The characteristics of the material determine the modification temperature required to achieve the target DEE concentration determined in step S7, and the heater 8 is controlled according to the determined modification temperature.

[0055] Next, proceed to step S9 to determine whether the modified DEE concentration detected by concentration sensor 3a is the target concentration. If step S9 is negative (S9: No), return to step S7; if step S9 is positive (S9: Yes), proceed to step S2, control switching valve 18 to close both the first and second flow paths, and end the process.

[0056] The following effects can be achieved by adopting this implementation method.

[0057] (1) The fuel modification device 100 comprises: a fuel tank 1 and a modified fuel tank 3, which store fuel from the internal combustion engine 5; a modifier 2, which modifies the fuel supplied from the fuel tank 1 according to temperature; a heater 8, which adjusts the temperature of the modifier 2; a first flow path, which guides the fuel modified by the modifier 2 to the gas phase of the fuel tank 1; a second flow path, which guides the fuel modified by the modifier 2 to the modified fuel tank 3; a switching valve 18, which opens either the first flow path or the second flow path; an external temperature sensor 19, which detects the external temperature; and a controller 20, which controls the switching valve 18 and the heater 8 according to the external temperature detected by the external temperature sensor 19. Figure 1 , Figure 2 ).

[0058] When the internal combustion engine 5 is started, if the external temperature detected by the external temperature sensor 19 exceeds the specified temperature (14°C), the controller 20 controls the switching valve 18 to open the first flow path. Figure 3 Additionally, when the internal combustion engine 5 starts, if the external temperature detected by the external temperature sensor 19 is below a specified temperature, the switching valve 18 is controlled to open the second flow path, and the heater 8 is controlled according to the external temperature detected by the external temperature sensor 19. Figure 3 , Figure 4 This ensures the combustibility, safety, and efficiency of modified fuels.

[0059] (2) The liquid fuel stored in fuel tank 1 contains ethanol as its main component. The modifier 2 modifies the ethanol contained in the fuel supplied from fuel tank 1 into DEE at a modification rate corresponding to the temperature. By adjusting the modification temperature and appropriately adjusting the modification rate, vapor lock caused by excess DEE can be reliably prevented.

[0060] (3) The fuel modification device 100 also includes a concentration sensor 1a for detecting the DEE concentration in the gas phase of the fuel tank 1. Figure 1 , Figure 2 When the internal combustion engine 5 is started, if the external temperature detected by the external temperature sensor 19 exceeds a specified temperature, the controller 20 controls the switching valve 18 to close the first flow path, provided that the DEE concentration detected by the concentration sensor 1a is above the upper explosive limit. Thus, the concentration of flammable gas in the vapor phase of the fuel tank 1 is maintained outside the explosive range, thereby reliably preventing the reaction between vaporized ethanol and oxygen (air) in the fuel tank 1.

[0061] (4) The fuel modification device 100 further comprises: a mixer 4, which mixes fuel stored in the fuel tank 1 and the modified fuel tank 3 with air to generate a mixture; and a concentration sensor 4a, which detects the ethanol concentration and DEE concentration in the mixture generated by the mixer 4. Figure 1 and Figure 2 The controller 20 controls the mixer 4 (electric pumps 7, 15, 17) to keep the concentrations of ethanol and DEE detected by the concentration sensor 4a within the explosive range. In this way, by keeping the concentration of combustible gases in the mixture supplied to the internal combustion engine 5 within the explosive range, the combustion performance of the internal combustion engine 5 can be ensured.

[0062] (5) The amount of catalyst in the modifier 2 that contains more Brønsted acid sites than the amount of H-ZSM-5 zeolite with a silica / alumina ratio of 24. As a result, the modification temperature required to achieve the target DEE concentration can be kept lower, and the energy consumption of the heater 8 can be reduced.

[0063] (6) The fuel modification device 100 also includes a condenser 13, which is disposed in the second flow path to condense the fuel modified by the modifier 2. Thus, the modified fuel can be stored as a liquid in the modified fuel tank 3.

[0064] In the above embodiments, utilizing Figure 1 Examples of adjusting the temperature of the modifier 2 by the heater 8 have been given, but the temperature adjustment unit for adjusting the temperature of the modifier is not limited to the above. For example, waste heat can also be utilized by the exhaust gas or cooling water of the internal combustion engine 5.

[0065] In the above embodiments, an example of using a switching valve 18 that can close both the first flow path and the second flow path is described. However, the switching valve can be any valve that can open either the first flow path or the second flow path, or it can be a switching valve that cannot close them.

[0066] In the above embodiment, an example was described in which the controller 20 controls the switching valve 18 to close the first flow path based on the condition that the DEE concentration of the gas phase of the fuel tank 1 detected by the concentration sensor 1a is a predetermined concentration (48 [vol%]) or higher. However, this is not a limitation. For example, a concentration sensor that detects oxygen concentration instead of the DEE concentration of the gas phase of the fuel tank 1 may be provided, and the first flow path may be closed based on the oxygen concentration of the gas phase. That is, when the DEE concentration of the gas phase of the fuel tank 1 is the upper explosive limit of 48 [vol%], the air concentration is 52 [vol%], and the oxygen concentration is approximately 10%. Therefore, the switching valve 18 may also be controlled to close the first flow path based on the condition that the oxygen concentration of the gas phase is a predetermined concentration (10 [vol%]) or lower.

[0067] It is possible to combine one or more of the above-described embodiments and variations, and to combine the variations with each other.

[0068] Using this invention, the combustibility, safety, and efficiency of fuel modification can be ensured.

[0069] The present invention has been described above in conjunction with preferred embodiments, but those skilled in the art should understand that various modifications and alterations can be made without departing from the scope of the following claims.

Claims

1. A fuel modification device (100), characterized in that, have: The first storage section (1) and the second storage section (3) store fuel for the internal combustion engine (5); A modifier (2) modifies the fuel supplied from the first storage unit (1) according to the temperature. Temperature adjustment unit (8) adjusts the temperature of the modifier (2); The first flow path guides the fuel modified in the modifier (2) into the gas phase of the first storage section (1); The second flow path guides the fuel modified in the modifier (2) to the second storage section (3); A switching valve (18) that opens either the first flow path or the second flow path; External temperature detection unit (19), which detects the external temperature; The controller (20) controls the switching valve (18) and the temperature adjustment unit (8) based on the external temperature detected by the external temperature detection unit (19). When the internal combustion engine (5) is started, if the external temperature detected by the external temperature detection unit (19) exceeds a specified temperature, the controller (20) controls the switching valve (18) to open the first flow path. When the internal combustion engine (5) is started, if the external temperature detected by the external temperature detection unit (19) is below the specified temperature, the controller (20) controls the switching valve (18) to open the second flow path and controls the temperature adjustment unit (8) according to the external temperature detected by the external temperature detection unit (19).

2. The fuel modification device (100) according to claim 1, characterized in that, The fuel stored in the liquid phase of the first storage section (1) contains alcohol. The modifier (2) modifies the alcohol contained in the fuel supplied from the first storage unit (1) into ether at a modification rate corresponding to the temperature.

3. The fuel modification device (100) according to claim 2, characterized in that, It also includes a concentration detection unit (1a) for detecting the concentration of ether in the gas phase of the first storage unit (1). When the internal combustion engine (5) is started, if the external temperature detected by the external temperature detection unit (19) exceeds the specified temperature, the controller (20) controls the switching valve (18) to close the first flow path, provided that the ether concentration detected by the concentration detection unit (1a) is above the upper limit of explosion.

4. The fuel modification device (100) according to claim 2 or 3, characterized in that, It also has: The mixer (4) mixes the fuel stored in the first storage section (1) and the second storage section (3) with air to generate a mixed gas; An alcohol concentration detection unit (4a) detects the alcohol concentration in the mixture generated by the mixer (4); and The ether concentration detection unit (4a) detects the ether concentration in the mixed gas generated by the mixer (4). The controller (20) controls the mixer (4) so ​​that the alcohol concentration detected by the alcohol concentration detection unit (4a) and the ether concentration detected by the ether concentration detection unit (4a) are within the explosion range.

5. The fuel modification device (100) according to claim 2 or 3, characterized in that, The alcohol is ethanol. The ether is diethyl ether.

6. The fuel modification device (100) according to any one of claims 1 to 3, characterized in that, The specified temperature is 14 degrees Celsius.

7. The fuel modification device (100) according to any one of claims 1 to 3, characterized in that, The amount of catalyst filling the modifier (2) with Brønsted acid sites is greater than the specified amount.

8. The fuel modification device (100) according to claim 7, characterized in that, The specified amount is the amount of Brønsted acidic sites in H-ZSM-5 zeolite with a silica-alumina ratio of 24.

9. The fuel modification device (100) according to any one of claims 1 to 3 and 8, characterized in that, It also includes a condenser (13) disposed in the second flow path to condense the fuel modified by the modifier (2).

10. The fuel modification device (100) according to any one of claims 1 to 3 and 8, characterized in that, The controller (20) stores a first characteristic showing the relationship between the external air temperature and the target concentration of the modified fuel, and a second characteristic showing the relationship between the target concentration and the modification temperature required to achieve the target concentration; When the internal combustion engine (5) is started, if the external temperature detected by the external temperature detection unit (19) is below the specified temperature, the target concentration is determined based on the external temperature detected by the external temperature detection unit (19) and the first characteristic, the modification temperature is determined based on the determined target concentration and the second characteristic, and the temperature adjustment unit (8) is controlled based on the determined modification temperature.

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