JP4345443B2 - In-vehicle fuel separation system - Google Patents

Description

  The present invention relates to a fuel separation system, and more particularly to a vehicle-mounted fuel separation system.

  A vehicle-mounted fuel separation system in which a fuel separation device is mounted on a vehicle driven by an internal combustion engine is known. For example, an apparatus described in Patent Document 1. In this system, raw fuel is separated into high-octane fuel and low-octane fuel by an on-vehicle fuel separator, and the separated fuel is stored in a high-octane fuel tank and low-octane fuel tank, from which high-octane fuel is stored. And a low-octane fuel are mixed so as to suit the operating conditions and supplied to the combustion chamber of the internal combustion engine.

  By the way, the fuel separation device includes a fractional type that fractionates the fuel into a high octane fuel tank and a low octane fuel, and a separation membrane type that separates the fuel into a high octane fuel tank and a low octane fuel with a separation membrane module. However, since the separation efficiency is low at room temperature, it is necessary to heat them. The fuel separator of Patent Document 1 is of the fractional distillation type, but is equipped with an electric heater and a hot water heater for cooling water of the internal combustion engine, and when the internal combustion engine has not been warmed up and the cooling water temperature is low. The separation system is heated by an electric heater, and when the internal combustion engine is warmed up and the cooling water temperature becomes high, the separation device is heated by the fuel engine cooling water. That is, two heating means are provided. As a result, the apparatus becomes complicated, the cost increases, and the battery load also increases.

JP 2001-050070 A

  In view of the above problems, an object of the present invention is to provide a vehicle-mounted fuel separation system that is simple, low-cost, and suppresses a load on a battery to increase separation efficiency.

According to the present invention, a vehicle driven by an internal combustion engine is mounted with a fuel separation device for separating a raw material fuel into a high-octane fuel having a relatively high octane number and a low-octane fuel having a relatively low octane number. In a fuel separation system, a fuel separation device that needs to be heated in order for the fuel separation device to exhibit separation ability, and includes a heating device that heats the fuel separation device, and the heating device uses engine cooling water as fuel. It consists of a hot water heater that allows heat to flow through the separation device, and stops the flow of engine cooling water to the hot water heater until the engine cooling water temperature reaches a predetermined separation device operation start temperature. together so as to stop the operation of the separation apparatus, the high-octane for storing high-octane fuel that has been separated from the low-octane fuel tank for storing the separated low-octane fuel When the sum of the remaining amount of the low-octane fuel tank and the remaining amount of the high-octane fuel tank is larger than a predetermined value, the fuel separation device determines the starting fuel as the high-octane fuel. When the sum of the remaining amount of the low-octane fuel tank and the remaining amount of the high-octane fuel tank is equal to or less than a predetermined value, the separation device operation start temperature is set as the fuel-separable temperature. An in-vehicle fuel separation system characterized in that it is lowered to the following is provided.
That is, in the on- vehicle fuel separation system according to the present invention , the fuel separation device is heated by a heating device composed of a hot water heater that allows the engine cooling water to flow through the fuel separation device in a heat transferable manner. Until the predetermined system operation start temperature is reached, the flow of the engine cooling water to the hot water heater can be stopped, and the operation of the fuel separator can be stopped. Therefore, the separation efficiency can be increased when the cooling water temperature is high. On the other hand, when the cooling water temperature is low, a large amount of aromatic components that are not separated into the low-octane fuel tank do not flow in, the octane number of the low-octane fuel tank becomes stable, and the separation device is stopped, so wasted energy is consumed. Fuel economy is improved.

Further, in the on- vehicle fuel separation system according to the present invention , the fuel separation device does not operate below the temperature at which fuel separation is possible, so that a large amount of aromatic components that are not separated into the low octane fuel tank flow into the octane number of the low octane fuel tank. It is reliably prevented from rising.

Furthermore, in the on- vehicle fuel separation system according to the present invention , when the sum of the low octane number fuel tank remaining amount and the high octane number fuel tank remaining amount is equal to or less than a predetermined value, the fuel separation device determines the system operation start temperature as the high octane number fuel. Therefore, the fuel separation device can be operated even when the cooling water temperature is low, and the amount of fuel supplied to the internal combustion engine can be secured. As long as the fuel is supplied, the stall situation can be avoided.

According to the present invention , the fuel separation device can be heated by the cooling water of the internal combustion engine to improve the separation efficiency, the structure is simple, the cost is low, and the fuel separation device is stopped when the cooling water temperature is low. Therefore, a large amount of aromatic components that are not separated into the low-octane fuel tank can be prevented from flowing in, and the octane number of the low-octane fuel tank can be stabilized. improves.
Further, according to the present invention, when the remaining amount of the separated fuel is small , the fuel separation device can be operated even when the cooling water temperature is low, the amount of fuel supplied to the internal combustion engine can be secured, and the fuel is supplied to the fuel separation device. As much as possible, you can avoid the situation of stalling.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing a schematic configuration of an embodiment of an on-vehicle fuel separator according to the present invention.
In FIG. 1, 1 is a vehicle, 2 is an internal combustion engine, and 11 and 12 are fuel injection valves of the internal combustion engine 2. In this embodiment, as will be described later, a high-octane fuel having a high octane number and a low-octane fuel having a low octane number are used, and two fuel injection valves 11, 12 are provided in each cylinder in order to inject each fuel individually. Is provided. In the example of FIG. 1, the fuel injection valve 11 for low octane fuel is an in-cylinder fuel injection valve that directly injects fuel into each cylinder, and the fuel injection valve 12 for high octane fuel is fuel at the intake port of each cylinder. Is a port injection valve.

  A fuel tank 3 stores fuel (gasoline). The tank 3 is supplied with ordinary (commercially available) gasoline and stored. In the present specification, gasoline stored in the fuel tank 3 is referred to as a raw material fuel in order to distinguish it from the separated fuel described later, and the fuel tank is also referred to as a raw material fuel tank. The fuel in the raw material fuel tank 3 is supplied to the fuel separator 10 by the feed pump 31 via the raw material fuel supply line 34, where a high octane fuel having a higher octane number than the raw material fuel and a low octane fuel having a lower octane number than the raw material fuel are provided. The separated fuel is stored in a low octane fuel tank 5 and a high octane fuel tank 7, respectively. In the present embodiment, the fuel separator 10 and the fuel tanks 3, 5, 7 are mounted on the vehicle 1 together with the internal combustion engine 2. The low-octane fuel tank 5 is provided with a fuel remaining amount meter 52 that detects the remaining amount of fuel in the low-octane fuel tank 5, and the high-octane fuel tank 7 is a fuel that detects the remaining fuel in the high-octane fuel tank 7. A fuel gauge 72 is attached.

  The low octane number fuel in the low octane number fuel tank 5 is supplied to the high pressure fuel injection pump 53 by the feed pump 51, and after being pressurized by the pump 53, is directly injected into each cylinder from the low octane number fuel injection valve 11. The high-octane fuel in the high-octane fuel tank 7 is supplied to the high-octane fuel injection valve 12 by the feed pump 71 and injected from the fuel injection valve 12 to the intake port of each cylinder.

  As described above, in the present embodiment, since the fuel injection valves that are independent from each other are used for the low-octane fuel and the high-octane fuel, one of the low-octane fuel and the high-octane fuel is selected according to the operating state of the engine. Or both of the fuels are simultaneously supplied to each cylinder of the internal combustion engine 2 at a predetermined ratio to improve engine performance and exhaust properties. That is, since the low octane fuel has very good ignitability, it can be used during engine start-up or cold operation to improve engine performance and exhaust properties. Since high-octane fuel is less likely to self-ignite and has high knock resistance, it can be used during high-power operation to advance the ignition timing and increase engine output.

The fuel separator 10 includes a separation unit 100, a heat exchanger 120, a gas-liquid separator 130, a feed line circulation line 140, a circulation pump 141, and the like.
The separation unit 100 includes a separation membrane module 110. The separation membrane module 110 has a structure in which a housing 110a made of a pressure vessel is divided into two compartments 113 and 115 by a separation membrane 111. As the separation membrane 111, one having a property of selectively permeating aromatic components in gasoline is used.

  In the separation membrane 111, the raw material fuel is supplied to one side of the separation membrane 111 (for example, the compartment 113 side, ie, the low octane fuel side) at a relatively high pressure, and the other side (eg, the compartment 115 side, ie, the high octane fuel). Is maintained at a relatively low pressure, the aromatic components in the raw material fuel permeate through the separation membrane 111 and leached out to the surface of the separation membrane 111 on the low pressure side (the compartment 115 side, ie, the high octane fuel side). Thus, the film surface facing the low pressure side 115 is covered. By removing the liquid leached fuel covering the low pressure side membrane surface, the leaching of aromatic components occurs continuously through the separation membrane 111 from the high pressure compartment 113 side to the low pressure compartment 115 side.

In the present embodiment, by maintaining the pressure on the low pressure side (in the compartment 115 side) at a pressure lower than the vapor pressure of the brewed aromatic component, the leached fuel containing a large amount of aromatic component covering the membrane surface on the low pressure side is obtained. It is evaporated and continuously removed from the surface and recovered in the form of fuel vapor. The fuel vapor recovered from the low pressure side section 115 of the separation membrane module 110 is sent to the gas-liquid separator 130 where it is cooled.
The aromatic component having a relatively high boiling point is liquefied, and a liquid-phase high-octane fuel containing a large amount of the aromatic component is generated below the gas-liquid separator 130. On the other hand, a low-boiling point fuel vapor having a lower octane number than the liquid phase fuel produced at the bottom is separated at the top of the gas-liquid separator 130.

  As is well known, as the amount of aromatic components in gasoline increases, the octane number (RON) of gasoline increases. For this reason, the octane number of the fuel containing a large amount of aromatic components recovered from the gas-liquid separator 130 is significantly higher than the octane number of the raw material fuel. On the other hand, the fuel remaining in the high-pressure side section 113 of the separation membrane 111, in which a part of the aromatic component is removed and the content of the high octane component is reduced, has a lower octane number than the raw fuel.

That is, when the raw material fuel is supplied to the high pressure side compartment 113 of the separation membrane module 110, the high octane fuel having a higher octane number than the raw material fuel is recovered from the low pressure side compartment 115 in the form of vapor and further generated by the gas-liquid separator 130. By separating and recovering the liquid phase, a high-octane fuel having an aromatic component and an octane number further increased is produced. On the other hand, from the high pressure side compartment 113, a part of the high octane number component (aromatic component) is removed from the raw material fuel, and the fuel having a lower octane number than the raw material fuel is recovered. It is mixed with the vapor after the liquid phase is separated to become a low octane fuel.
That is, by supplying the raw material fuel to the separation membrane module 110, the raw material fuel is separated into a high octane fuel and a low octane fuel.

  The heat exchanger 120 is, for example, a normal shell and tube or plate type heat exchanger, and the return line 54 to the low-octane fuel tank 5 and the raw fuel supply line 34 pass through the inside. The low-octane fuel in the return line 54 to the fuel tank 5 of the low-octane fuel separated by the separation unit 100 and the raw fuel in the raw fuel supply line from the raw fuel tank 3 to the separation unit 100 are heat exchanged. To do.

The circulation line 140 and the circulation pump 141 shown above the separation unit 100 in the drawing operate as follows.
The raw material fuel is supplied from the tank 3 by the raw material fuel supply pump 31 via the raw material fuel supply line 34 to the circulation line 140 of the separation unit 100 via the heat exchanger 120, and in the circulation line 140, the raw material fuel is supplied to the separation membrane module 110. Is supplied to the high-pressure compartment 113 and contacts the separation membrane 111. The raw material fuel that has come into contact with the separation membrane 111, that is, the low-octane fuel, is supplied to the high-pressure section 113 of the separation membrane module 110 via the circulation line 140 by the circulation pump 141.

  The low-octane fuel in the circulation line 140 is recovered to the low-octane fuel tank 5 through the recovery line 54. The recovery pipe 54 is provided with a control valve 55. By controlling the opening degree of the control valve 55, the flow in the circulation line 140 and the raw fuel separation unit 100 are controlled to control the temperature of the separation membrane module 110. The supply amount and pressure to the are controlled.

  A jet pump 131 is attached to the gas-liquid separator 130, and the jet pump 131 is connected to the low pressure compartment 115 of the separation membrane module 110 via the low pressure compartment fuel suction line 133, and the pressure in the low pressure compartment 115 of the separation membrane module 110 is For example, the pressure is maintained at about 50 kPa. The fuel that has oozed out on the surface of the separation membrane 111 on the low pressure compartment 115 side is sucked into the gas-liquid separator 130 as fuel vapor. Since not only a high octane component but also a low octane component passes through the separation membrane 111, the fuel vapor contains a high octane component and a low octane component.

  Most of the aromatic component (high octane component) is liquefied by the gas-liquid separator 130, and the other components (low octane component) are in a gaseous state. Therefore, the fuel vapor sucked from the low pressure section 115 is separated in the gas-liquid separator 130 into a liquid-phase high-octane fuel and a gas-phase low-octane fuel vapor.

  The upper part of the gas-liquid separator 130 and the low pressure section 115 of the separation membrane module 110 are connected by a low octane fuel vapor circulation line 137. The gas phase low octane fuel vapor in the gas-liquid separator 130 is recycled to the separation membrane module low pressure section 115. Thereby, in the low pressure section 115, only the vapor pressure of the low octane component increases while maintaining the vapor pressure of the high octane component low, and the selective permeability of the high octane component (aromatic component) is improved. The circulation line 137 is provided with a flow rate control valve 135, and by controlling the flow rate of the low octane fuel vapor flowing through the circulation line 137, the pressure difference between the low pressure section 115 and the gas-liquid separator 130 can be appropriately adjusted. Value is maintained.

Further, a liquid-phase high-octane fuel circulation line 138 and a circulation pump 139, and a high-octane fuel recovery line 77 that connects the circulation line 138 and the high-octane fuel tank 7 are provided below the gas-liquid separator 130. A liquid level control valve 75 is disposed on the recovery line 77. Further, a liquid level detector 75a for detecting the liquid level in the gas-liquid separator 130 is provided.
When the liquid level of the high octane fuel in the gas-liquid separator 130 reaches a predetermined high level, the liquid level control valve 75 is opened. When the liquid level control valve 75 is opened, the high-octane fuel discharged from the circulation pump 139 flows into the high-octane fuel tank 7 from the recovery line 77. As a result, the high-octane fuel separated and generated by the fuel separator 10 is transferred to the fuel tank 7.
On the other hand, when the liquid level of the high-octane fuel in the gas-liquid separator 130 is lowered to a predetermined low level, the liquid level control valve 75 is closed, and the high-octane fuel discharged from the circulation pump 139 passes through the circulation line 138. It circulates in the gas-liquid separator 130.

  When the high-octane fuel circulates in the gas-liquid separator 130, the low-pressure portion 115 of the separation membrane module 110 as described above due to the negative pressure generated when passing through the jet pump 131 and passing through the venturi portion in the jet pump 131. The fuel vapor inside is sucked into the gas-liquid separator 130.

  Further, a low octane fuel vapor recovery line 57 that connects the low octane fuel vapor circulation line 137 and the low octane fuel tank 5 is provided. The low-octane fuel vapor recovery line 57 is connected to the suction side of a jet pump 59 similar to the jet pump 131 disposed downstream of the control valve 55 of the low-octane fuel recovery line 54 after separation. When the control valve 55 is opened and liquid low-octane fuel flows in the jet pump 59, the low-octane fuel vapor in the gas-liquid separator 130 is sucked by the jet pump 59 and is liquid in the jet pump 59. It is mixed with fuel and collected in the low octane fuel tank 5. As a result, the low-octane fuel vapor in the gas-liquid separator 130 is recovered in the low-octane fuel tank 5 and the pressure in the gas-liquid separator 130 is prevented from increasing.

As described above, in the present embodiment, the raw material fuel is separated into the high-octane fuel and the low-octane fuel.
By the way, in order to increase the ratio (permeability) of the aromatic component in the raw material fuel that permeates the separation membrane, that is, to increase the yield of the high octane fuel, the temperature on the low pressure side of the separation membrane 111 is optimal. Must be in the temperature range.

  Therefore, in the present embodiment, the separation unit 100 is heated with the cooling water of the internal combustion engine 2 so that the temperature of the raw material fuel supplied to the separation membrane is in the optimum temperature range, and the separation performance of the separation membrane 111 is improved. The yield of the high octane fuel after separation is set to a predetermined ratio or more with respect to the raw material fuel, and the octane number is higher than the octane number of the raw material fuel by a predetermined value or more.

  For this reason, the separation unit 100 is provided with a hot water heater 112 using the cooling water of the internal combustion engine 2. The hot water heater 112 allows the cooling water of the internal combustion engine to pass through the cooling water passage 207 formed in the separation unit 100. The cooling water passage 207 is disposed around the separation membrane module 111 so that not only the fuel pipes formed in the upper part of the separation unit 100 in the figure but also the separation membrane module 110 can be heated.

  Since the cooling water of the internal combustion engine 2 is allowed to flow through the cooling water passage 207, the cooling water circuit 200 of the internal combustion engine 2 will be described here. A cooling water circuit for heating the passenger compartment is omitted because it is not related to the present invention. First, 201 is a radiator, 202 is a thermostat valve, 203 is a water pump, 204 is an engine internal coolant passage, 205 is a cross pipe, and 206 is an electromagnetic three-way valve.

  The first port 202 a of the thermostat valve 202 is connected to the outlet 201 b of the radiator 201 through the first cooling water passage 211. The second port 202 b of the thermostat valve 202 is connected to the inlet 203 a of the water pump 203 through a short second cooling water passage 212. The third port 202 c of the thermostat valve 202 is connected to the fourth port 205 d of the cross tube 205 by the third cooling water passage 213.

  The upstream end of the engine internal cooling water passage 204 is directly connected to the outlet 203b of the water pump 203, and the downstream end of the engine internal cooling water passage 204 is connected to the first port 205a of the cross tube 205 and the fourth cooling water passage 214. Yes. The second port 205 b of the cross tube 205 and the first port 206 a of the electromagnetic three-way valve 206 are connected by a fifth cooling water passage 215. The second port 206 b of the electromagnetic three-way valve 206 and the inlet 201 a of the radiator 201 are connected by a sixth cooling water passage 216.

  The inlet 207a of the cooling water passage 207 in the separation unit 100 is connected to the third port 205c of the cross tube 205 by the seventh cooling water passage 217, and the outlet 207b of the cooling water passage 207 of the separation unit 100 is an electromagnetic three-way valve 206. The third port 206 c is connected to the eighth cooling water passage 218. The electromagnetic three-way valve 206 is controlled by an ECU (electronic control unit) 30.

Hereinafter, temperature control of the separation unit 100 configured as described above will be described.
When the cooling water temperature is equal to or higher than a predetermined temperature, specifically, equal to or higher than the temperature at which the separation membrane module 110 is operated, the ECU 30 causes the third port 206c and the second port 206b of the electromagnetic three-way valve 206 to communicate with each other. At the same time, the feed pump 31 in the raw material fuel tank 3, the circulation pump 141, the circulation pump 139 attached to the gas-liquid separator 130, the liquid level control valve 75, the control valve 55 of the low octane number fuel recovery line 54, the low octane number fuel The fuel separator 10 is operated by operating the flow control valve 135 of the steam circulation line 137. The coolant temperature is detected by a water temperature sensor 15 provided at the outlet of the engine internal coolant passage 204.

  However, if the cooling water is allowed to flow through the cooling water passage 207 in the separation unit 100 immediately after the cold start, the separation is not performed satisfactorily and aromatic components are mixed into the low octane fuel tank 5 and the octane number of the low octane fuel tank 5 is reduced. Increases, and the octane number of the high-octane fuel tank 7 decreases. Therefore, when the cooling water temperature is equal to or lower than the predetermined value, the ECU 30 closes the third port 206c of the electromagnetic three-way valve 206, and feeds the feed pump 31 in the raw fuel tank 3 and the circulation pump 141 attached to the separation unit 100. , The circulation pump 139 attached to the gas-liquid separator 130, the liquid level control valve 75, the control valve 55 of the low octane number fuel recovery line 54, and the flow rate control valve 135 of the low octane number fuel vapor circulation line 137 are stopped to separate the fuel. The apparatus 10 is stopped.

  FIG. 2 is a flowchart of the above control. In step 201, it is determined whether or not the internal combustion engine 2 is in operation. If a negative determination is made, the process jumps to step 207 and ends. If the determination is affirmative, in step 202, it is determined whether or not the engine coolant temperature THWeg has reached the predetermined system operation determination temperature THWcr.

  If an affirmative determination is made in step 202, the electromagnetic three-way valve 206 or the like is controlled so that the cooling water of the internal combustion engine 2 flows to the separation unit 100 as described above in step 203, and the fuel separation device 10 is operated in step 204. Then, the process proceeds to step 207 and ends. Conversely, if a negative determination is made in step 202, the electromagnetic three-way valve 206 and the like are controlled in step 205 so that the cooling water of the internal combustion engine 2 does not flow into the separation unit 100 as described above, and in step 206 the fuel separation device 10 is stopped, then the process proceeds to step 207 and ends.

  As described above, in the present embodiment, the separation efficiency of the separation unit 100 is increased by the cooling water of the internal combustion engine 2, and a power heater using a battery is not used, which contributes to energy saving as a whole system. . Further, the temperature of the cooling water after warming up the internal combustion engine 2 is approximately 80 to 90 ° C., and is within the optimum temperature range (about 75 to 125 ° C.) of the separation membrane module 110 described above for temperature adjustment. No additional device is required, and the device can be made smaller.

  Next, a modification of the above embodiment will be described. In this modification, when the sum of the remaining amount of the low-octane fuel tank 5 and the remaining amount of the high-octane fuel tank 7 is equal to or less than a predetermined value, the system operation determination temperature THWcr of the fuel separator 10 is lowered, and the internal combustion engine 2 The fuel separation device 10 is operated to ensure the fuel that can be supplied to the fuel injection valves 11 and 12 even when the temperature of the cooling water does not increase the separation efficiency of the high octane fuel of the separation unit 100. FIG. 3 shows a flowchart of control in this modification.

In FIG. 3, in step 301, it is determined whether or not the internal combustion engine 2 is in operation as in step 201 of FIG. If a negative determination is made, the process jumps to step 311 and ends. If the determination is affirmative, in step 302, the remaining amount Qlr of the low-octane fuel tank 5 and the remaining amount Qhr of the high-octane fuel tank 7 are added to calculate the total remaining fuel amount Qtl. It is determined whether or not the amount Qtl is larger than a predetermined value Qcr.
The remaining amount Qlr of the low-octane fuel tank 5 is detected by a fuel meter 52 attached to the low-octane fuel tank 5, and the remaining amount Qhr of the high-octane fuel tank 7 is a fuel meter 72 attached to the high-octane fuel tank 7. Is detected.

  If the determination in step 303 is affirmative, that is, if the total fuel remaining amount Qtl is larger than the predetermined value Qcr and the remaining amount is large, the process proceeds to step 304, and the system operation determination temperature THWcr is set to a normal value, that is, separation is good. Set to THWcr1, which is the value for performing Conversely, if a negative determination is made in step 303, that is, if the total fuel remaining amount Qtl is smaller than the predetermined value Qcr and the remaining amount is small, the process proceeds to step 305 and the system operation determination temperature THWcr is set to the normal value THWcr1. Is set to a lower THWcr2 and the process proceeds to Step 306. Steps 306 to 311 are the same as steps 202 to 207 in FIG.

  That is, in step 306, it is determined whether or not the engine coolant temperature THWeg has reached the predetermined system operation determination temperature THWcr. If an affirmative determination is made in step 306, the electromagnetic three-way valve 206 and the like are controlled so that the cooling water of the internal combustion engine 2 flows into the separation unit 100 as described above in step 307, and the fuel separation device 10 is operated in step 308. Then, the process proceeds to step 311 and ends. Conversely, if a negative determination is made in step 306, the electromagnetic three-way valve 206 and the like are controlled in step 309 so that the cooling water of the internal combustion engine 2 does not flow into the separation unit 100 as described above, and in step 310 the fuel separation device After 10 is stopped, the process proceeds to step 311 and ends.

  The modification of the embodiment of the present invention is configured and operates as described above. When the sum of the remaining amount of the low-octane fuel tank 5 and the remaining amount of the high-octane fuel tank 7 is less than a predetermined value, the internal combustion engine Even if the temperature of the cooling water of the engine 2 is low, the fuel separator 10 is operated, and fuel that can be supplied to the fuel injection valves 11 and 12 is secured. Therefore, as long as there is fuel in the raw fuel tank 3, the fuel is supplied to the low octane number fuel tank 5 and the high octane number fuel tank 7, and the engine stall is avoided. At this time, since an aromatic component that is not separated flows into the low-octane fuel tank 5, the octane number of the fuel in the tank 5 increases but is allowed.

  Since the present embodiment and its modification are as described above, when the warm-up of the internal combustion engine 2 is completed, the entire separation unit 100 is heated by the cooling water of the internal combustion engine 2. As a result, the low-octane fuel separated by the separation unit 100 and directed to the low-octane fuel tank 5 is also heated to the same temperature as the cooling water of the internal combustion engine 2, that is, about 80 ° C. Since this temperature is much higher than the boiling point of the low octane fuel, it is preferable to lower the temperature of the low octane fuel before storing in the low octane fuel tank 5. Therefore, as described above, the heat exchanger 120 is provided to heat the raw material fuel with the heat of the heated low octane fuel.

  The heat exchanger 120 preferably exchanges heat between the raw fuel and the low-octane fuel at the portion where the temperature of the low-octane fuel is the highest. Therefore, the heat exchanger 120 is provided in the portion closest to the separation unit 100 of the low octane fuel pipe and the raw fuel pipe, and the low octane fuel temperature is lowered by heat dissipation through the pipe wall before reaching the heat exchanger 120. It is preferable that the raw material fuel exiting the heat exchanger 120 reaches the separation unit 100 before the temperature is lowered due to heat dissipation through the pipe wall.

  The present invention separates a raw fuel into a high-octane fuel and a low-octane fuel with an on-vehicle fuel separator, and stores the separated fuel in a high-octane fuel tank and a low-octane fuel tank, from which a high-octane fuel is stored. And a low-octane fuel can be mixed so as to suit the operating conditions and supplied to the combustion chamber of the internal combustion engine.

It is a figure which shows typically schematic structure of one Embodiment of the vehicle-mounted fuel separation system of this invention. It is a flowchart of control of an embodiment of the invention. It is a flowchart of control of the modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle 2 ... Internal combustion engine 3 ... Raw material fuel tank 5 ... Low octane number fuel tank 7 ... High octane number fuel tank 10 ... Fuel separator 30 ... Electronic control unit (ECU)
DESCRIPTION OF SYMBOLS 100 ... Separation unit 110 ... Separation membrane module 111 ... Separation membrane 120 ... Heat exchanger 130 ... Gas-liquid separator 201 ... Radiator 202 ... Thermostat valve 203 ... Water pump 204 ... Engine cooling water channel 205 ... Cross pipe 206 ... Electromagnetic three-way Valve 207 ... (in the separation unit) Cooling water passage

Claims (1)

In a vehicle-mounted fuel separation system in which a vehicle driven by an internal combustion engine is equipped with a fuel separation device that separates a raw material fuel into a high-octane fuel having a relatively high octane number and a low-octane fuel having a relatively low octane number,
A fuel separation device that requires heating in order for the fuel separation device to exhibit separation ability,
A heating device for heating the fuel separation device, the heating device is constituted by a hot water heater that allows the engine cooling water to flow through the fuel separation device in a heat transferable manner;
Until the engine cooling water temperature reaches a predetermined separation device operation start temperature, the circulation of the engine cooling water to the hot water heater is stopped, and the operation of the fuel separation device is stopped .
A low-octane fuel tank that stores the separated low-octane fuel and a high-octane fuel tank that stores the separated high-octane fuel,
When the sum of the remaining amount of the low-octane fuel tank and the remaining amount of the high-octane fuel tank is greater than a predetermined value, the fuel separation device can separate the raw material fuel into the high-octane fuel and the low-octane fuel at the start temperature of the separation device. Let the fuel separation temperature,
If the sum of the remaining amount of the low-octane fuel tank and the remaining amount of the high-octane fuel tank is equal to or less than a predetermined value, the operation start temperature of the separator is lowered to the fuel-separable temperature or less,
An in-vehicle fuel separation system characterized by the above.

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