JP2014227895A - Controller of fuel separation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a fuel separation system capable of avoiding boil of fuel by stopping the fuel separation system after a fuel temperature becomes equal to or lower than a prescribed temperature.SOLUTION: A fuel separation system 1 includes a stop control part which, when a fuel separation system 1 is requested to be stopped, stops a negative pressure pump 141, and then stops a fuel pump 102 and a temperature-decrease heat exchanger 16 in response to that fuel flowing to a separation membrane 122 within a separator 12 after the temperature of the fuel is increased by a temperature-rise heat exchanger 11 becomes equal to or lower than a prescribed temperature.

Description

  The present invention relates to a control device for a fuel separation system. More specifically, the present invention relates to a control device for a fuel separation system that separates a mixed fuel of alcohol and gasoline into a high-octane fuel having a high octane number and a low-octane fuel having a low octane number.

  As fuel for internal combustion engines (hereinafter referred to as “engines”), alcohol fuel that can be produced from many crops such as sugar cane, corn, and potatoes has attracted attention. Particularly in recent years, mixed fuels in which alcohol fuel is added to gasoline are in circulation and are expected to become more widespread in the future. There are various types of alcohol fuel such as ethanol and methanol, and ethanol is the most popular among these.

  Along with the widespread use of the above mixed fuels, the mixed fuel supplied from the outside while the vehicle is running is separated into high gasoline concentration fuel (low octane fuel) and high alcohol concentration fuel (high octane fuel) by the separation membrane. Fuel separation systems that separate again are known. There are various differences in fuel properties such as octane number and calorific value between gasoline and alcohol.Therefore, instead of using the mixed fuel supplied from the outside as it is, it is separated again on the vehicle and put into the engine operating state. This is because it may be preferable to use gasoline and alcohol properly. For example, since alcohol has better knock resistance than gasoline, knocking is suppressed by supplying alcohol to the engine.

  By the way, in the above-mentioned fuel separation system, it is necessary to raise the temperature of the fuel by, for example, a temperature raising heat exchanger using engine coolant from the viewpoint of improving the separation efficiency of the separation membrane. Therefore, after the system is operated, a certain amount of time is required until a necessary temperature condition (for example, the fuel temperature is approximately 70 degrees) is satisfied and the system functions normally. Therefore, immediately after the engine is started, a sufficient amount of low-octane fuel and high-octane fuel (hereinafter referred to as “separated fuel”) are referred to. ) Cannot be supplied to the engine. In view of this, a system has been proposed in which the fuel separation system stop time is delayed by a predetermined time with respect to the engine stop time, so that necessary separated fuel is ensured immediately after the next engine start (see, for example, Patent Document 1).

Japanese Patent No. 4706503

  However, in the system of Patent Document 1, the predetermined time is set based on the degree of deterioration over time of the separation efficiency of the fuel separation unit. That is, the driving time of the fuel separation system after the engine is stopped is determined regardless of the fuel temperature. Therefore, the fuel separation system may be stopped in a state where the temperature of the fuel cannot be lowered sufficiently. In this case, the fuel may boil in the heat exchanger for temperature increase. Further, depending on the activation temperature of the reforming catalyst provided in the shunt reformer of the fuel separator, there is a risk that the fuel will boil in the fuel separator.

  The present invention has been made in view of the above, and an object of the present invention is to provide a control device for a fuel separation system that can avoid boiling of fuel by stopping the fuel separation system after the fuel temperature becomes equal to or lower than a predetermined temperature. There is to do.

  In order to achieve the above object, the present invention provides a first tank (for example, a main tank 10 described later) that stores a mixed fuel of alcohol and gasoline, and a fuel pump (for example, described later) that pumps the mixed fuel in the first tank. Fuel pump 102), a temperature raising heat exchanger (for example, temperature raising heat exchanger 11 described later) for raising the temperature of the mixed fuel pumped by the fuel pump, and the temperature raising heat exchanger. A separator (for example, a separation membrane 122 described later) that separates the heated mixed fuel into a high-octane fuel having a higher octane number than that of the mixed fuel and a low-octane fuel having a lower octane number than that of the mixed fuel The separator 12), which will be described later, the heat exchanger for lowering the temperature of the low-octane fuel separated by the separator (for example, the heat exchanger 16 for lowering temperature described later), and the separator. A second tank for storing octane fuel (for example, a high octane fuel tank 15 to be described later) and a negative pressure pump (for example, to be described later) having a negative pressure on the second tank side from the separation membrane in the separator. Negative pressure pump 141), and a control device (for example, an ECU 5 described later) of a fuel separation system (for example, an after-mentioned fuel separation system 1), and when there is a request to stop the fuel separation system, After the negative pressure pump is stopped, the fuel pump and the temperature-decreasing heat are heated in response to the temperature of the fuel heated by the temperature-raising heat exchanger and flowing into the separator being equal to or lower than a predetermined temperature. Provided is a control device for a fuel separation system, comprising stop control means (for example, an ECU 5 and a stop control unit described later) for stopping the exchanger.

In the present invention, when there is a request to stop the fuel separation system, first, the negative pressure pump is stopped. Thereafter, the fuel pump and the temperature lowering heat exchanger are stopped when the temperature of the fuel heated by the temperature raising heat exchanger and flowing into the separator becomes equal to or lower than a predetermined temperature.
According to the present invention, the fuel pressure is sufficiently cooled in order to operate the fuel pump and the temperature lowering heat exchanger for a predetermined time after stopping the negative pressure pump and stopping the secondary side device through which the high-octane fuel flows. Then, the temperature can be lowered. Therefore, it is possible to avoid boiling of the fuel in the heat exchanger and to reduce the amount of evaporated fuel. As a result, expensive parts having high durability are not required, and the cost can be reduced.

  The temperature raising heat exchanger has a cooling water passage (for example, an after-mentioned LLC passage 111) through which cooling water of an internal combustion engine (for example, an engine 2 described later) flows, and a flow rate of the cooling water flowing through the cooling water passage. It is preferable that the flow rate adjusting valve (for example, a flow rate adjusting valve 112 described later) to be adjusted is provided, and the stop control unit closes the flow rate adjusting valve after stopping the negative pressure pump.

In the present invention, when there is a request to stop the fuel separation system, the negative pressure pump is stopped, and then the flow rate adjustment valve is closed (fully closed), so that the cooling water passage included in the temperature raising heat exchanger is provided. Stops the flow of cooling water flowing inside.
According to this invention, since the flow of the cooling water is stopped after the negative pressure pump is stopped, the fuel flowing in the fuel separation system is not heated by the heat exchanger for temperature increase. It is possible to cool and cool the temperature more reliably.

  The fuel separation system communicates with the first tank and the second tank and adsorbs evaporated fuel discharged from these tanks (for example, a canister 18 to be described later), the canister and an intake passage of the internal combustion engine, A purge passage (for example, a purge passage 183 to be described later) communicating therewith, and a purge valve (for example, a purge valve 181 to be described later) provided in the purge passage for opening or closing the purge passage. When there is no request to stop the internal combustion engine, the control means opens the purge passage by the purge valve until the predetermined time elapses after the negative pressure pump is stopped. After the predetermined time has elapsed after being supplied into the intake passage and combusted, the purge passage is shut off by the purge valve so that the evaporated fuel is removed. It is preferable to adsorb the Nisuta.

In the present invention, when there is a request for stopping the fuel separation system, there is no request for stopping the engine (when the ignition switch is not turned off or when there is no idle stop request), that is, when fuel separation is completed or when the high octane number is high. When it is necessary to prevent overflow from the relationship with the remaining amount in the fuel tank, evaporation is performed by opening the purge passage with the purge valve until the predetermined time elapses after the negative pressure pump is stopped. Fuel is supplied into the intake passage and burned. In addition, after a predetermined time has elapsed, the purge passage is blocked by the purge valve so that the evaporated fuel is adsorbed to the canister.
According to the present invention, when fuel separation is completed or when it is necessary to prevent overflow from the relationship with the remaining amount in the high-octane fuel tank, the negative pressure pump is stopped for a predetermined time (for example, 5 seconds). ), The evaporated fuel purge process normally performed while the engine is running is extended and executed. Thus, the amount of evaporated fuel can be further reduced by appropriately processing the evaporated fuel. As a result, the canister can be miniaturized.

  The fuel separation system communicates with the first tank and the second tank and adsorbs evaporated fuel discharged from these tanks (for example, a canister 18 to be described later), the canister and an intake passage of the internal combustion engine, A purge passage (for example, a purge passage 183 to be described later) communicating therewith, and a purge valve (for example, a purge valve 181 to be described later) provided in the purge passage for opening or closing the purge passage. The control means opens the purge passage by the purge valve during a predetermined time after the negative pressure pump is stopped until the internal combustion engine is stopped when there is a request to stop the internal combustion engine. As a result, the evaporated fuel is supplied into the intake passage for combustion, and after the predetermined time has elapsed, the purge passage is shut off by the purge valve. In it is preferable to adsorb the fuel vapor to the canister.

In the present invention, when there is a request for stopping the fuel separation system and when there is a request for stopping the engine, that is, when the ignition switch is turned off or when there is an idle stop request, the negative pressure pump is stopped. By elapse of a predetermined time and until the engine is stopped, the purge passage is opened by the purge valve, whereby the evaporated fuel is supplied into the intake passage and burned. In addition, after a predetermined time has elapsed, the purge passage is blocked by the purge valve so that the evaporated fuel is adsorbed to the canister.
According to the present invention, when the ignition switch is turned off or there is an idle stop request, the evaporated fuel purge normally performed during engine operation for a predetermined time (for example, 5 seconds) until the engine is stopped. Extend the process and execute it. Thus, the amount of evaporated fuel can be further reduced by appropriately processing the evaporated fuel. As a result, the canister can be miniaturized.

  It is preferable that the stop control means maintains the state in which fuel separation can be started promptly after the idle stop is canceled by continuing to drive the fuel pump while the vehicle is in an idle stop.

In the present invention, the fuel pump is continuously driven while the vehicle is in an idle stop, thereby maintaining a state where fuel separation can be started immediately after the release of the idle stop.
According to the present invention, the fuel pump is continuously driven during the idling stop, and the fuel pressure is applied to the fuel to control the temperature, so that the separation of the fuel can be started immediately after the idling stop is released. Therefore, fuel can be separated more efficiently.

  The temperature raising heat exchanger includes a cooling water passage (for example, an LLC passage 111 described later) through which cooling water of the internal combustion engine flows, and a flow rate adjusting valve (for example, a flow rate adjusting valve for adjusting the flow rate of the cooling water flowing through the cooling water passage). The fuel separation system control device determines whether or not a failure has occurred in the fuel separation system (for example, an ECU 5, a failure determination unit described later). And a failure event determination means (for example, an ECU 5, a failure event determination section described later) for determining a failure event based on a determination result of the failure determination means, wherein the stop control means is controlled by the failure determination means. When it is determined that a failure has occurred in the fuel separation system, the negative pressure pump, the fuel pump, and the temperature lowering heat exchanger are immediately turned on according to the determination result by the failure event determination means. Stop and immediately close the flow rate adjustment valve, or stop the negative pressure pump and close the flow rate adjustment valve, and then the temperature is raised by the heat-up heat exchanger and flows into the separator It is preferable to select whether to stop the fuel pump and the temperature lowering heat exchanger in response to the temperature of the fuel to be reduced below a predetermined temperature.

In this invention, when it is determined that a failure has occurred in the fuel separation system, the negative pressure pump, the fuel pump, and the temperature lowering heat exchanger are immediately stopped and the flow rate adjustment valve is closed according to the determination result of the failure event. After closing the valve (fully closed) or closing the negative pressure pump and closing the flow rate adjustment valve (fully closed), the temperature of the fuel that is heated by the heat exchanger for temperature rise and flows into the separator It is selected whether to stop the fuel pump and the temperature lowering heat exchanger in response to the temperature becoming lower than the predetermined temperature.
According to the present invention, when a serious failure occurs, the negative pressure pump, the fuel pump, and the temperature lowering heat exchanger are immediately stopped, and the flow rate adjustment valve is closed (fully closed). The entire fuel separation system including the primary side device can be immediately stopped. Also, in the event of a non-critical failure, the fuel pressure fell below the specified temperature after stopping the negative pressure pump, stopping the 2 o'clock side device, and closing the flow rate adjustment valve (fully closed) By stopping the fuel pump and the temperature lowering heat exchanger later to stop the primary device, the system can be stopped while avoiding fuel boiling. Therefore, according to the present invention, the fuel separation system can be stopped at an optimal timing according to the failure situation.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the fuel separation system which can avoid boiling of a fuel can be provided by stopping a fuel separation system after fuel temperature becomes below predetermined temperature.

It is a figure showing composition of a fuel separation system of an internal-combustion engine concerning one embodiment of the present invention. It is a flowchart which shows the procedure of stop control of the fuel separation system which concerns on the said embodiment.

An embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a fuel separation system 1 for an engine 2 according to an embodiment of the present invention. The fuel separation system 1 of the engine 2 is mounted on a vehicle (not shown), and a mixed fuel of ethanol and gasoline, a high octane fuel having a higher ethanol concentration than the mixed fuel and a higher octane number, and an ethanol concentration than the mixed fuel while the vehicle is running. Separated into low octane fuel with low octane number.

  As shown in FIG. 1, the fuel separation system 1 of the engine 2 according to the present embodiment includes a main tank 10, a heat exchanger 11 for raising temperature, a separator 12, a condenser 13, and a high octane fuel buffer tank. 14, a high octane fuel tank 15, a temperature lowering heat exchanger 16, a canister 18, and an electronic control unit (hereinafter referred to as “ECU”) 5. The fuel separation system 1 is divided into a primary side device and a secondary side device with a later-described separation membrane 122 provided in the separator 12 as a boundary. That is, the primary side apparatus is configured to include the main tank 10, the temperature raising heat exchanger 11, and the temperature lowering heat exchanger 16, and the low octane fuel separated by the separation membrane 122 mainly circulates. . Further, the secondary device includes a condenser 13, a high octane fuel buffer tank 14, a high octane fuel tank 15, and a negative pressure pump 141, and the high octane fuel separated by the separation membrane 122. Is mainly distributed.

  The main tank 10 stores a mixed fuel of ethanol and gasoline supplied from a fuel filler port. In this embodiment, the most popular mixed fuel (E10) having an ethanol content of 10% is preferably used as the mixed fuel. Connected to the main tank 10 is a first fuel passage 101 for supplying fuel to a heat exchanger 11 for raising temperature and a separator 12 described later.

Further, as will be described later, the low-octane fuel separated by the separation membrane 122 is introduced into the main tank 10, mixed with the mixed fuel in the main tank 10, and again used for separation. This is because the high-octane component cannot be completely separated only by bringing the mixed fuel into contact with the separation membrane 122 once, so it is necessary to contact the separation membrane 122 a plurality of times.
Accordingly, the fuel in the main tank 10 circulates through the primary side device and contacts the separation membrane 122 a plurality of times, so that the high octane component concentration gradually decreases. Hereinafter, the fuel circulating through the primary side device is simply referred to as fuel.

A fuel pump 102 connected to the first fuel passage 101 is provided in the reservoir 10 a in the main tank 10. The number of revolutions of the fuel pump 102 is controlled by the ECU 5, whereby the mixed fuel in the main tank 10 is supplied into the temperature raising heat exchanger 11 through the first fuel passage 101.
A first temperature sensor 104 is provided in the first fuel passage 101 on the upstream side of the temperature raising heat exchanger 11. The first temperature sensor 104 detects the temperature of the fuel supplied into the temperature raising heat exchanger 11 through the first fuel passage 101 and outputs a detection signal corresponding to the detected temperature to the ECU 5.

The temperature raising heat exchanger 11 is provided in the middle of the first fuel passage 101, and heat exchange between the fuel supplied from the fuel pump 102 via the first fuel passage 101 and the cooling water (LLC) of the engine 2 is performed. To heat.
An LLC passage 111 through which the cooling water for the engine 2 flows is connected to the temperature raising heat exchanger 11, and the cooling water for the engine 2 flows through the temperature raising heat exchanger 11. The LLC passage 111 is provided with a flow rate adjusting valve 112 that adjusts the flow rate of the cooling water flowing in the LLC passage 111, and the flow rate adjusting valve 112 is controlled by the ECU 5. Further, a water temperature sensor 113 is provided on the LLC passage 111 on the engine 2 side, and the water temperature sensor 113 detects the temperature of the cooling water flowing through the LLC passage 111 and outputs a detection signal corresponding to the detected temperature to the ECU 5. .
The temperature raising heat exchanger 11 may further include an electric heater, or may be replaced with an electric heater.

The separator 12 supplies the mixed fuel heated and supplied by the temperature raising heat exchanger 11 to a high octane fuel having a higher ethanol concentration and a higher octane number than the mixed fuel, and a low octane fuel having a lower ethanol concentration and a lower octane number. And to separate.
A second temperature sensor 126 is provided in the first fuel passage 101 downstream of the temperature raising heat exchanger 11 and upstream of the separator 12. The second temperature sensor 126 detects the temperature of the fuel that is heated by the temperature raising heat exchanger 11 and is supplied to the separator 12, and outputs a detection signal corresponding to the detected temperature to the ECU 5.

  The separator 12 is a separator using a pervaporation method (pervaporation method). The separator 12 is a separation membrane 122 that selectively permeates ethanol, which is a high-octane component in the mixed fuel, a high-pressure chamber 123 and a low-pressure chamber 124 that are partitioned by the separation membrane 122, and the pressure in the low-pressure chamber 124. And a pressure sensor 125 to detect.

  The high pressure chamber 123 is connected to the first fuel passage 101 downstream of the temperature raising heat exchanger 11 and is maintained at a high pressure by the fuel pump 102 provided in the first fuel passage 101. The low pressure chamber 124 is connected to the intake side of the negative pressure pump 141 via a condenser 13 and a high octane fuel buffer tank 14 which will be described later, and is thereby kept at a negative pressure. A pressure sensor 125 is provided in the low pressure chamber 124. The pressure sensor 125 detects the pressure in the low-pressure chamber 124 and outputs a detection signal corresponding to the pressure to the ECU 5.

When the fuel heated by the temperature raising heat exchanger 11 is supplied into the high pressure chamber 123, the high octane component ethanol selectively permeates the separation membrane 122 and the high octane fuel is leached into the low pressure chamber 124. . On the other hand, low-octane fuel remains in the high-pressure chamber 123. As a result, the fuel is separated into a high-octane fuel and a low-octane fuel.
The separation efficiency of the separator 12 is adjusted by the temperature and flow rate of the supplied fuel and the pressure in the high pressure chamber 123 and the low pressure chamber 124.

The condenser 13 condenses the high-octane fuel in the gaseous state. The condenser 13 is disposed below the separator 12. The upstream side of the condenser 13 is connected to the low pressure chamber 124 of the separator 12, and the downstream side thereof is connected to the intake side of the negative pressure pump 141 via a high octane fuel buffer tank 14 described later. Thereby, the inside of the condenser 13 is controlled to a negative pressure, and the high octane fuel in the gaseous state is supplied from the low pressure chamber 124 into the condenser 13 and condensed.
The condenser 13 is an air-cooled condenser, and includes a plurality of plate-shaped fins 130 and a cooling fan 132. The number of rotations of the cooling fan 132 is controlled by the ECU 5. Note that a water-cooled condenser may be used as the condenser 13.

The high octane fuel buffer tank 14 temporarily stores high octane fuel under a negative pressure. The high octane number fuel buffer tank 14 is disposed below the condenser 13. The upper space 146 of the high-octane fuel buffer tank 14 is connected to the lower part 134 of the condenser 13 by the third communication path 133 and is connected to the intake side of the negative pressure pump 141 described later. Thereby, the inside of the high octane fuel buffer tank 14 is controlled to a negative pressure, and the high octane fuel is supplied from the condenser 13 into the high octane fuel buffer tank 14.
A third check passage 133 that connects the upper space 146 of the high-octane fuel buffer tank 14 and the lower part 134 of the condenser 13 has a second check that prevents the flow of fuel from the high-octane fuel buffer tank 14 to the condenser 13. A valve 131 is provided.
A high octane fuel buffer tank remaining amount sensor 148 for detecting the remaining amount of high octane fuel is provided in the high octane fuel buffer tank 14.

  The high octane fuel tank 15 stores high octane fuel under atmospheric pressure. The high octane fuel tank 15 is disposed below the high octane fuel buffer tank 14. The upper space 154 of the high octane fuel tank 15 is communicated with the storage portion 147 of the high octane fuel buffer tank 14 by the second communication path 145. The second communication passage 145 is provided with a first check valve 143 that prevents the flow of fuel from the high octane fuel tank 15 to the high octane fuel buffer tank 14.

The reservoir 155 of the high octane fuel tank 15 is connected to the exhaust side of the negative pressure pump 141 whose intake side is connected to the upper space 146 of the high octane fuel buffer tank 14. The upper space 154 of the high octane fuel tank 15 is communicated with the intake side of the negative pressure pump 141 by the first communication path 144. The first communication path 144 is provided with a pressure control valve 142 that opens or closes the first communication path 144. The number of rotations of the negative pressure pump 141 and the opening / closing of the pressure control valve 142 are controlled by the ECU 5. The pressure control valve 142 is composed of, for example, an electromagnetic valve.
In the high octane fuel tank 15, a high octane fuel tank remaining amount sensor 156 for detecting the remaining amount of high octane fuel is provided.

When the pressure control valve 142 is opened after the operation of the negative pressure pump 141 is stopped, the upper space 146 of the high-octane fuel buffer tank 14 is shut off from the intake side of the negative pressure pump 141, while being under atmospheric pressure. It communicates with the upper space 154 of the high octane fuel tank 15. As a result, the negative pressure in the high-octane fuel buffer tank 14 is released, and the internal pressure in the high-octane fuel buffer tank 14 becomes approximately atmospheric pressure. Then, the first check valve 143 is opened by the own weight of the high octane fuel stored in the storage unit 147 of the high octane fuel buffer tank 14, and the high octane fuel is transferred into the high octane fuel tank 15.
In addition, since the internal pressure of the high-octane fuel buffer tank 14 becomes approximately atmospheric pressure, a differential pressure is generated between the internal pressure of the condenser 13 and the second check valve 131 is thereby closed. The negative pressure in the 12 low-pressure chambers 124 and in the condenser 13 is maintained. Strictly speaking, although there is a negative pressure drop due to the progress of fuel separation, the negative pressure in the low-pressure chamber 124 and the condenser 13 of the separator 12 is maintained for a short time, and separation can be continued.

  The high-octane fuel stored in the high-octane fuel tank 15 is boosted to a predetermined pressure by the fuel pump 151 provided in the storage portion 155 of the high-octane fuel tank 15 and is pumped into the high-octane fuel passage 152. The pumped high-octane fuel is appropriately injected into the intake port 30 of the engine 2 by the port injector 51. The rotational speed of the fuel pump 151 and the injection timing and injection time of the port injector 51 are controlled by the ECU 5.

  Further, the upper space 154 of the high octane fuel tank 15 is connected to a canister 18 described later via a two-way valve 153. When the pressure in the high octane fuel tank 15 becomes higher than the pressure in the canister 18, the evaporated fuel in the high octane fuel tank 15 is supplied into the canister 18. On the other hand, when the pressure in the high octane fuel tank 15 becomes lower than the pressure in the canister 18, the evaporated fuel in the canister 18 is supplied into the high octane fuel tank 15.

The temperature lowering heat exchanger 16 cools the low-octane fuel separated by the separator 12. The heat-decreasing heat exchanger 16 of the present embodiment is configured with a radiator. The temperature lowering heat exchanger 16 is provided in the middle of the second fuel passage 121 and is arranged on the downstream side of the separator 12. The temperature lowering heat exchanger 16 includes a plurality of corrugated fins 160 and a cooling fan 161. The rotation speed of the cooling fan 161 is controlled by the ECU 5. The high-temperature low-octane fuel separated by the separation membrane 122 is cooled by the temperature-decreasing heat exchanger 16.
A third temperature sensor 162 is provided at the outlet of the temperature lowering heat exchanger 16. The third temperature sensor 162 detects the temperature of the fuel cooled by the temperature lowering heat exchanger 16 and outputs a detection signal corresponding to the detected temperature to the ECU 5.

  The downstream side of the temperature lowering heat exchanger 16 is connected to the main tank 10 by the second fuel passage 121. That is, the low-octane fuel separated by the separation membrane 122 is supplied into the main tank 10 and mixed with the mixed fuel before separation, and is supplied to the separator 12 again. In this manner, the fuel circulates between the main tank 10 and the separation membrane 122 until the high octane component concentration in the fuel becomes equal to or lower than a predetermined threshold value at which it can be determined that the separation is completed.

A fuel pressure regulator 165 is provided in the second fuel passage 121. The fuel pressure regulator 165 removes the fuel pressure of the fuel flowing in the second fuel passage 121.
Further, in the first fuel passage 101 on the upstream side of the temperature raising heat exchanger 11, as a high octane number component concentration detecting unit capable of detecting or estimating the high octane number component concentration in the fuel, for example, a high octane number such as an ethanol sensor or the like. A component concentration sensor 166 is provided. The high octane number component concentration sensor 166 detects the high octane number component concentration in the fuel and outputs a detection signal corresponding to this to the ECU 5.

When the high octane component concentration in the fuel detected by the high octane component concentration sensor 166 is equal to or less than a predetermined threshold at which separation can be determined, the high octane component concentration in the main tank 10 is sufficiently small. Low octane fuel is stored.
The low-octane fuel in the main tank 10 is pressurized to a predetermined pressure by the fuel pump 103 provided in the reservoir 10 a of the main tank 10 and is pumped into the low-octane fuel passage 106. The pumped low-octane fuel is appropriately injected into the combustion chamber 20 of the engine 2 by the direct injection injector 52. The number of revolutions of the fuel pump 103 and the injection timing and injection time of the direct injection injector 52 are controlled by the ECU 5.

  The upper space 10b of the main tank 10 is connected via a canister 18 and a two-way valve 105 described later. When the pressure in the high octane fuel tank 15 becomes higher than the pressure in the canister 18, the evaporated fuel in the high octane fuel tank 15 is supplied into the canister 18. On the other hand, when the pressure in the high octane fuel tank 15 becomes lower than the pressure in the canister 18, the evaporated fuel in the canister 18 is supplied into the high octane fuel tank 15.

  The canister 18 communicates with the main tank 10 and the high octane fuel tank 15 and adsorbs the evaporated fuel discharged from these tanks. More specifically, the canister 18 incorporates an adsorbent such as activated carbon, and adsorbs and holds high octane component ethanol and low octane component gasoline (hydrocarbon). The canister 18 communicates with the intake port 30 of the engine 2 via the purge passage 183. The purge passage 183 is provided with a purge valve 181 for opening or closing the purge passage 183, and the opening and closing of the purge valve 181 is controlled by the ECU 5.

Since the intake port 30 is in a negative pressure state, when the purge valve 181 is opened, ethanol and gasoline (hydrocarbon) adsorbed and held by the canister 18 are evaporated again to become evaporated fuel. Then, the air is supplied into the intake port 30 through the opened purge passage 183 (hereinafter referred to as “fuel purge process”). As a result, the evaporated fuel is supplied into the combustion chamber 20 of the engine 2 and burned. This fuel purge process is executed when the ignition switch is turned on.
When the purge valve 181 is closed, the purge passage 183 is shut off, and the evaporated fuel generated in the main tank 10 and the high-octane fuel tank 15 is discharged and adsorbed to the canister 18 (hereinafter referred to as “canister”). This canister processing is executed when the ignition switch is turned off and during idle stop.
Air components such as nitrogen other than the evaporated fuel are discharged from the canister 18 through the discharge passage 182 to the outside of the vehicle.

  The engine 2 is a multi-cylinder engine having a plurality of cylinders 23. FIG. 1 representatively shows one of them. The engine 2 is configured by combining a cylinder block 21 in which a cylinder 23 is formed and a cylinder head 22. A piston 24 is slidably provided in the cylinder 23. A combustion chamber 20 of the engine 2 is formed by the top surface of the piston 24 and the surface of the cylinder head 22 on the cylinder 23 side. The piston 24 is connected to a crankshaft (not shown) via a connecting rod. That is, a crankshaft (not shown) rotates according to the reciprocating motion of the piston 24 in the cylinder 23.

  The engine 2 is provided with an intake pipe 3 through which intake air flows and an exhaust pipe 4 through which exhaust flows. The cylinder head 22 is formed with an intake port 30 that connects the combustion chamber 20 and the intake pipe 3, and an exhaust port 40 that connects the combustion chamber 20 and the exhaust pipe 4. An intake opening facing the combustion chamber 20 in the intake port 30 is opened and closed by an intake valve 27. An exhaust opening facing the combustion chamber 20 in the exhaust port 40 is opened and closed by an exhaust valve 28.

  The cylinder head 22 is provided with an ignition plug 29 facing the combustion chamber 20, an intake camshaft (not shown) that drives the intake valve 27 to open and close, and an exhaust camshaft that drives the exhaust valve 28 to open and close. The spark plug 29 is connected to the ECU 5 via an igniter (not shown) and its driver, and the ignition timing is controlled by the ECU 5.

  The intake pipe 3 is provided with a compressor, an intercooler, and a throttle valve 31 (not shown) in order from the upstream side to the downstream side. The throttle valve 31 controls the flow rate (intake flow rate) of air supplied into the combustion chamber 20 of the engine 2. The throttle valve 31 is connected to the ECU 5 via a driver (not shown).

  The exhaust pipe 4 is provided with a turbocharger turbine (not shown) and an exhaust purification catalyst for purifying exhaust gas in order from the upstream side to the downstream side. The exhaust purification catalyst is, for example, a three-way catalyst, and purifies HC, CO, NOx, etc. in the exhaust.

  The ECU 5 is an electronic control unit that controls the engine 2 and the fuel separation system 1 and includes electronic circuits such as a CPU, a ROM, a RAM, and various interfaces. Further, the ECU 5 determines whether or not a failure has occurred in the fuel separation system 1, a fuel separation control unit that performs fuel separation control of the fuel separation system 1 to be described later, a stop control unit that performs stop control, and the fuel separation system 1. A failure determination unit and a failure event determination unit that determines a failure event based on the determination result of the failure determination unit are configured. The ECU 5 is connected to the above-described various sensors, valves, pumps, fans, and the like in order to grasp the state of the engine 2 and the fuel separation system 1 and the state of the vehicle on which these are mounted.

Next, the operation of the fuel separation control in the fuel separation system 1 according to this embodiment will be described.
First, the mixed fuel supplied into the main tank 10 is supplied to the heat-up heat exchanger 11 provided in the middle of the first fuel passage 101 by the fuel pump 102 (fuel pressure 300 to 400 kPa), for the purpose of raising the temperature. Heating is performed by heat exchange with the cooling water of the engine 2 flowing through the heat exchanger 11. The heated mixed fuel is supplied to the separation membrane 122 in the separator 12, and the high octane component (alcohol) selectively permeates the separation membrane 122. Thereby, the mixed fuel is separated into a high-octane fuel and a low-octane fuel.

  The high-octane fuel separated in the low-pressure chamber 124 is in a gas state, and is supplied from the low-pressure chamber 124 kept in the negative pressure state by the action of the negative pressure pump 141 into the condenser 13 that is also kept in the negative pressure state. Is done. The high-octane fuel in the gaseous state is condensed in the condenser 13 to be in a liquid state, and then supplied into the high-octane fuel buffer tank 14 maintained in a negative pressure state by the action of the negative pressure pump 141. Is temporarily stored.

The high-octane fuel in the high-octane fuel buffer tank 14 is transferred into the high-octane fuel tank 15 at a predetermined timing. Specifically, by opening the pressure control valve 142 after the operation of the negative pressure pump 141 is stopped, the upper space 146 of the high octane fuel buffer tank 14 is blocked from the intake side of the negative pressure pump 141. , Communicated with the upper space 154 of the high-octane fuel tank 15 under atmospheric pressure. Thereby, the pressure in the high octane fuel buffer tank 14 becomes atmospheric pressure. Then, the first check valve 143 is opened by the dead weight of the high-octane fuel stored in the storage unit 147 of the high-octane fuel buffer tank 14, and the high-octane fuel is supplied into the high-octane fuel tank 15.
At this time, in the condenser 13 above the high-octane fuel buffer tank 14 and in the low-pressure chamber 124 of the separator 12, there is only a negative pressure drop corresponding to the progress of fuel separation, and the negative pressure is maintained. Separation continues.

After the transfer of the high-octane fuel from the high-octane fuel buffer tank 14 to the high-octane fuel tank 15 is completed, the pressure control valve 142 is closed and the negative pressure pump 141 is started, so that the high-octane fuel buffer tank is started again. 14 is in a negative pressure state, and the first check valve 143 is closed.
The high-octane fuel that has been transferred and stored in the high-octane fuel tank 15 is appropriately injected into the intake port 30 by the port injector 51. Further, the evaporated fuel generated in the main tank 10 and the high octane fuel tank 15 is adsorbed by the canister 18 and then purged to be used for combustion of the engine 2.

  On the other hand, the liquid low-octane fuel separated in the high-pressure chamber 123 is cooled by the temperature-decreasing heat exchanger 16 and then the fuel pressure is removed by the fuel pressure regulator 165. Thereafter, the low-octane fuel is returned to the main tank 10 and mixed with the mixed fuel, and again supplied to the separator 12. Since the high-octane component cannot be completely separated only by bringing the mixed fuel into contact with the separation membrane 122 once, it is brought into contact with the separation membrane 122 a plurality of times. When the high octane component concentration detected by the high octane component concentration sensor 166 is equal to or lower than a predetermined threshold value, it is determined that the separation is completed, and the fuel separation control is terminated. The low octane fuel in the main tank 10 is appropriately injected into the combustion chamber 20 of the engine 2 by the direct injection injector 52.

  FIG. 2 is a flowchart showing a stop control procedure of the fuel separation system 1 according to this embodiment. The stop control of this embodiment is repeatedly executed by the ECU 5.

In step S1, it is determined whether or not there is a request to stop the fuel separation system 1. If this determination is YES, the process proceeds to step S2, and if this determination is NO, this process ends.
Here, the stop request of the fuel separation system 1 is (1) the high octane fuel remaining amount detected by the high octane fuel tank remaining amount sensor 156 in the high octane fuel tank 15 is equal to or greater than a predetermined threshold, and overflow is prevented. (1 ′) When it is determined that the high-octane component concentration in the fuel detected by the high-octane component concentration sensor 166 is equal to or lower than a predetermined threshold and the fuel separation is completed, (2) This is requested when there is a vehicle idle stop request, (3) when the vehicle ignition switch is turned off, or (4) when the fuel separation system 1 fails (failure), and the stop flag is “0”. To “1”.

  In step S2, it is determined whether or not the fuel separation system 1 is stopped. That is, it is determined whether or not both the primary side device and the secondary side device are stopped. If this determination is NO, the process proceeds to step S3, and if this determination is YES, this process ends.

In step S3, it is determined whether or not a failure (failure) has occurred in the fuel separation system 1. If this determination is YES, the process proceeds to step S4 to determine the failure event that has occurred. On the other hand, if this determination is NO, the process proceeds to step S7.
Here, as the failure (failure), (5) the temperature of the fuel in the main tank 10 detected by the first temperature sensor 104 due to the failure of the cooling fan 161 of the heat exchanger 16 for lowering the temperature or the control abnormality is predetermined. When the fuel temperature cannot be lowered in the cases of (5 ′) and (5), (6) the negative pressure of the secondary side device exceeds the predetermined threshold due to damage of the separation membrane 122 or the like. In some cases, (7) When the fuel pressure of the primary device is below a predetermined threshold due to piping breakage or clogging of the passage, (8) Due to sticking of the flow rate adjustment valve 112 in the LLC passage 11 or control abnormality, And the case where the temperature of the fuel heated by the heat exchanger 11 and flowing into the separation membrane 122 is equal to or higher than a predetermined threshold. In these cases, it is determined that a failure has occurred, and the failure flag is set from “0” to “1”.

In step S4, it is determined whether or not the failure event that has occurred is a serious failure (serious failure). If this determination is YES, since a serious failure has occurred, the process proceeds to step S5 and the fuel separation system 1 is immediately stopped (both the primary side device and the secondary side device are immediately stopped, that is, negative pressure is applied). The pump 141, the fuel pump 102, and the temperature lowering heat exchanger 16 are immediately stopped, and the flow rate adjusting valve 112 is immediately closed). Further, when this determination is NO, the failure that has occurred is not serious, so the process proceeds to step S6 and the temperature of the fuel (mainly low-octane fuel) flowing through the primary device is sufficiently lowered before the fuel is discharged. After the separation system 1 is stopped (that is, the negative pressure pump 141 is stopped and the flow rate adjustment valve 112 is closed), the temperature of the fuel that is heated by the temperature raising heat exchanger 11 and flows into the separator 12 is a predetermined temperature. In response to the following, the fuel pump 102 and the temperature-decreasing heat exchanger 16 are stopped), and this process is terminated.
Here, a serious failure (serious failure) is a failure event that greatly affects the system unless the system is immediately stopped. Among the failures (failures) of (5) to (8) described above, (5 ′) and (7) can be cited as serious failures (serious failure).

  In step S7, the negative pressure pump 141 is stopped, and the process proceeds to step S8. Thereby, separation of fuel is stopped and the secondary side device is stopped.

  In step S8, it is determined whether or not there is a request to stop the engine 2. When this determination is NO, that is, when there is a request for stopping the fuel separation system 1 but there is no request for stopping the engine 2, specifically, in the case of the above (1) or (1 ′), the process proceeds to step S9. Move. On the other hand, if this determination is YES, that is, if there is a request to stop the fuel separation system 1 and there is also a request to stop the engine 2, specifically, in the case of the above (2) or (3), step S13. Move on.

In step S9, in the case of (1) or (1 ′) described above, it is determined whether or not a predetermined time has elapsed since the negative pressure pump 141 was stopped in step S7. Here, the predetermined time is set in advance to a time corresponding to an emission delay of the evaporated fuel in a pipe connecting each tank and the canister 18. The predetermined time is set to the same value as the predetermined time in step S13 described later.
If this determination is NO, the evaporated fuel in the pipe has not been sufficiently discharged, so the routine proceeds to step S10, the fuel purge process is continued, and the routine proceeds to step S16. On the other hand, if this determination is YES, the fuel vapor in the pipe has been sufficiently discharged, so the process proceeds to step S11 to end the fuel purge process, and the process proceeds to step S12 to end the stop of the secondary side device. Thereby, the evaporated fuel generated in each tank is adsorbed by the canister 18 by the canister process.
In the fuel purge process, a purge correction coefficient for correcting the fuel injection amount of each injector in a decreasing direction is calculated based on the purge flow rate and the evaporated fuel concentration, and the evaporated fuel amount based on the calculated purge correction coefficient It is preferable to inject the fuel amount subtracted from each injector.

In step S13, (2) when a vehicle idle stop request is received, or (3) when a predetermined time has elapsed since the negative pressure pump 141 was stopped in step S7 when the vehicle ignition switch was turned off. Determine whether or not. As described above, this predetermined time is set to the same value as the predetermined time in step S9.
If this determination is NO, the evaporated fuel in the pipe has not yet been sufficiently discharged, so the process proceeds to step S15 until the engine 2 is stopped, and the fuel purge process is continued.
On the other hand, if this determination is YES, the evaporated fuel in the pipe has been sufficiently discharged, so the routine proceeds to step S14 where the fuel purge process is terminated and the engine 2 is allowed to stop. Thereby, the evaporated fuel generated in each tank is adsorbed by the canister 18 by the canister process. Thereafter, the process proceeds to step S12, and the stop of the secondary device is finished.
Thus, steps S13 to S15 function as an off timer for the secondary device.

  In step S16, it is determined whether or not the vehicle is in idle stop (I / S). If this determination is YES, the process moves to step S17, the fuel pump 102 is turned on, and this process is terminated. Thereby, the fuel pressure is applied to the fuel and the temperature is adjusted, so that the separation of the fuel can be started promptly after the idle stop is released.

  In step S <b> 18, it is determined whether or not the temperature of the fuel heated by the temperature raising heat exchanger 11 and flowing into the separator 12 is equal to or lower than a predetermined temperature. Specifically, it is determined whether or not the temperature of the fuel detected by the second temperature sensor 126 is equal to or lower than a predetermined temperature. Here, the predetermined temperature is set in advance to a value at which the fuel does not boil in the heat exchanger 11 for temperature increase or the like.

If this determination is YES, it is determined that the temperature of the fuel has been sufficiently lowered. Therefore, the process proceeds to step S19, where the fuel pump 102 and the cooling fan 161 of the temperature lowering heat exchanger 16 are turned off. Further, the LLC passage 111 is turned off by the flow rate adjusting valve 112 of the heat exchanger 11 for temperature increase. Next, the process proceeds to step S21, the stop of the primary side device is finished, and this process is finished.
On the other hand, if this determination is NO, it is determined that the temperature of the fuel has not yet been sufficiently lowered, so the routine proceeds to step S20, where the fuel pump 102 and the cooling fan 161 of the temperature decreasing heat exchanger 16 are turned on. At the same time, the LLC passage 111 is turned off by the flow rate adjusting valve 112 of the temperature-raising heat exchanger 11, and this process is terminated. Thereby, cooling of the fuel which distribute | circulates a primary side apparatus is performed efficiently.

  Therefore, (1) when the remaining amount of high-octane fuel is equal to or greater than a predetermined threshold and it is necessary to prevent overflow, and (1 ′) the concentration of high-octane component in the fuel is equal to or lower than the predetermined threshold and the fuel is separated. If it is determined that the processing has been completed, processing via steps S9 and S18 is executed. In this case, as in step S19 and step S20, the LLC passage is turned off (that is, the flow rate adjustment valve 112 is closed (fully closed), and so on).

  In addition, (2) when there is a vehicle idle stop request, processing through steps S13 and S17 is executed. In this case, the LLC path is not turned off.

In addition, (3) when the ignition switch of the vehicle is turned off, the process through step S15 and step S18 is executed before the predetermined time in step S13 elapses. In this case, the LLC passage 111 is turned off as in step S19 and step S20.
Thereafter, after a predetermined time has elapsed in step S13, processing via steps S14 and S18 is executed. In this case, it is not particularly necessary to turn off the LLC passage 111 because the engine 2 is stopped.

  According to this embodiment, the following effects are produced.

In the present embodiment, when there is a request to stop the fuel separation system 1, first, the negative pressure pump 141 is stopped. Thereafter, the fuel pump 102 and the temperature lowering heat exchanger 16 are stopped when the temperature of the fuel heated by the temperature raising heat exchanger 11 and flowing into the separator 12 becomes equal to or lower than a predetermined temperature.
According to this embodiment, after the negative pressure pump 141 is stopped and the secondary side device through which the high-octane fuel flows is stopped, the fuel pump 102 and the temperature lowering heat exchanger 16 are operated for a predetermined time. Can be cooled sufficiently to lower the temperature. Therefore, it is possible to avoid boiling of the fuel in the heat exchanger and to reduce the amount of evaporated fuel. As a result, expensive parts having high durability are not required, and the cost can be reduced.

In the present embodiment, when there is a request to stop the fuel separation system 1, the negative pressure pump 141 is stopped, and then the flow rate adjustment valve 112 is closed (fully closed), whereby the heat-up heat exchanger 11 is raised. The flow of the cooling water flowing through the LLC passage 111 included in the is stopped.
According to this embodiment, since the flow of the cooling water is stopped after the negative pressure pump 141 is stopped, the fuel flowing through the fuel separation system 1 is not heated by the heat exchanger 11 for heating. The fuel temperature can be cooled and lowered more reliably.

In the present embodiment, when there is a request for stopping the fuel separation system 1, there is no request for stopping the engine 2 (when the ignition switch is not turned off or when there is no idle stop request), that is, when fuel separation is completed. If it is necessary to prevent overflow from the relationship with the remaining amount in the high-octane fuel tank 15, the purge valve 181 purges the purge passage 183 until a predetermined time elapses after the negative pressure pump 141 is stopped. Is released, the evaporated fuel is supplied into the intake port 30 and burned. In addition, after a predetermined time has elapsed, the purge passage 183 is blocked by the purge valve 181 so that the evaporated fuel is adsorbed to the canister 18.
According to the present embodiment, when fuel separation is completed or when it is necessary to prevent overflow from the relationship with the remaining amount in the high-octane fuel tank 15, the negative pressure pump 141 is stopped for a predetermined time ( For example, the evaporative fuel purging process normally performed while the engine 2 is being driven is extended and executed for 5 seconds. Thus, the amount of evaporated fuel can be further reduced by appropriately processing the evaporated fuel. As a result, the canister 18 can be reduced in size.

In the present embodiment, when there is a request for stopping the fuel separation system 1 and when there is a request for stopping the engine 2, that is, when the ignition switch is turned off or when there is an idle stop request, the negative pressure pump 141 is turned on. The purge valve 181 opens the purge passage 183 until a predetermined time elapses after the stop and the engine 2 is stopped, whereby the evaporated fuel is supplied into the intake port 30 and burned. In addition, after a predetermined time has elapsed, the purge passage 183 is blocked by the purge valve 181 so that the evaporated fuel is adsorbed to the canister 18.
According to the present embodiment, when the ignition switch is turned off or when there is an idle stop request, the evaporation normally performed during driving of the engine 2 for a predetermined time (for example, 5 seconds) until the engine 2 is stopped. Extend the fuel purge process. Thus, the amount of evaporated fuel can be further reduced by appropriately processing the evaporated fuel. As a result, the canister 18 can be reduced in size.

In the present embodiment, the fuel pump 102 is continuously driven while the vehicle is in an idle stop, thereby maintaining a state where fuel separation can be started immediately after the release of the idle stop.
According to the present embodiment, the fuel pump is continuously driven during the idle stop, and the fuel pressure is applied to the fuel to control the temperature, so that the separation of the fuel can be started promptly after the release of the idle stop. Therefore, fuel can be separated more efficiently.

In this embodiment, when it is determined that a failure has occurred in the fuel separation system 1, the negative pressure pump 141, the fuel pump 102, and the temperature lowering heat exchanger 16 are immediately stopped according to the determination result of the failure event. The flow rate adjustment valve 112 is closed (fully closed), or the negative pressure pump 141 is stopped and the flow rate adjustment valve 112 is closed (fully closed), and then the temperature is raised by the heat-up heat exchanger 11. Whether the fuel pump 102 and the temperature lowering heat exchanger 16 are to be stopped is selected in response to the temperature of the fuel flowing into the separator 12 being equal to or lower than a predetermined temperature.
According to this embodiment, when a serious failure occurs, the negative pressure pump 141, the fuel pump 102, and the temperature lowering heat exchanger 16 are immediately stopped and the flow rate adjustment valve 112 is closed (fully closed), The entire fuel separation system 1 including the secondary device and the primary device can be stopped immediately. Further, when a non-critical failure occurs, the negative pressure pump 141 is stopped, the 2 o'clock side device is stopped, and the flow rate adjustment valve 112 is closed (fully closed), and then the fuel temperature becomes a predetermined temperature or less. Then, by stopping the fuel pump 102 and the temperature lowering heat exchanger 16 and stopping the primary side device, the system can be stopped while avoiding fuel boiling. Therefore, according to this embodiment, the fuel separation system 1 can be stopped at an optimal timing according to the failure state.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
In the said embodiment, although the use of the mixed fuel of ethanol and gasoline was assumed, this invention is not limited to this. The alcohol component mixed with gasoline is not limited to ethanol, but may be methanol, butanol, or the like.

In the above embodiment, the low octane fuel separated by the separator 12 is returned to the main tank 10, but the present invention is not limited to this. For example, a low octane fuel tank may be provided separately, and the low octane fuel may be stored in the low octane fuel tank.
Further, a circulation circuit may be provided in addition to the low octane fuel tank, and a small amount of fuel may be circulated in the circulation circuit so as to be separated.

DESCRIPTION OF SYMBOLS 1 ... Fuel separation system 2 ... Engine (internal combustion engine)
5 ... ECU (control device, stop control means, failure determination means, failure event determination means)
10 ... Main tank (first tank)
11 ... Heat exchanger for temperature increase 12 ... Separator 15 ... High octane fuel tank (second tank)
16 ... Heat exchanger for cooling 18 ... Canister 102 ... Fuel pump 111 ... LLC passage (cooling water passage)
DESCRIPTION OF SYMBOLS 112 ... Flow control valve 122 ... Separation membrane 141 ... Negative pressure pump 181 ... Purge valve 183 ... Purge passage

Claims (6)

A first tank for storing a mixed fuel of alcohol and gasoline;
A fuel pump for pumping the mixed fuel in the first tank;
A temperature raising heat exchanger for raising the temperature of the mixed fuel pumped by the fuel pump;
A separator comprising a separation membrane that separates the mixed fuel heated by the heat-up heat exchanger into a high-octane fuel having a higher octane number than the mixed fuel and a low-octane fuel having a lower octane number than the mixed fuel;
A heat exchanger for lowering the temperature of the low-octane fuel separated by the separator;
A second tank for storing high-octane fuel separated by the separator;
A control device of a fuel separation system comprising: a negative pressure pump that makes the pressure on the second tank side negative from the separation membrane in the separator,
When the fuel separation system is requested to stop, after the negative pressure pump is stopped, the temperature of the fuel that is heated by the heat exchanger for temperature increase and flows into the separator becomes a predetermined temperature or less. A control device for a fuel separation system, comprising stop control means for stopping the fuel pump and the temperature lowering heat exchanger according to the situation. The heat exchanger for temperature increase includes a cooling water passage through which cooling water of the internal combustion engine flows, and a flow rate adjustment valve that adjusts the flow rate of the cooling water flowing through the cooling water passage,
2. The control device for a fuel separation system according to claim 1, wherein the stop control unit closes the flow rate adjusting valve after stopping the negative pressure pump. 3. The fuel separation system comprises:
A canister that communicates with the first tank and the second tank to adsorb the evaporated fuel discharged from these tanks;
A purge passage communicating the canister and the intake passage of the internal combustion engine;
A purge valve provided in the purge passage and opening or closing the purge passage;
When there is no request for stopping the internal combustion engine, the stop control means opens the purge passage by the purge valve until a predetermined time elapses after the negative pressure pump is stopped. 2. The fuel is supplied to the intake passage and burned, and after the predetermined time has elapsed, the purge fuel is adsorbed to the canister by blocking the purge passage with the purge valve. Or the control apparatus of the fuel separation system of 2. The fuel separation system comprises:
A canister that communicates with the first tank and the second tank to adsorb the evaporated fuel discharged from these tanks;
A purge passage communicating the canister and the intake passage of the internal combustion engine;
A purge valve provided in the purge passage and opening or closing the purge passage;
When there is a request to stop the internal combustion engine, the stop control means causes the purge valve to open the purge passage during a predetermined time after the negative pressure pump is stopped until the internal combustion engine is stopped. The evaporative fuel is supplied into the intake passage and burned by being opened, and the evaporative fuel is adsorbed to the canister by shutting off the purge passage by the purge valve after the predetermined time has elapsed. The control apparatus of the fuel separation system according to claim 1 or 2, characterized by the above-mentioned.   5. The stop control means maintains a state in which fuel separation can be started promptly after the idle stop is canceled by continuing driving of the fuel pump during idle stop of the vehicle. The control apparatus of the fuel separation system as described. The heat exchanger for temperature increase includes a cooling water passage through which cooling water of the internal combustion engine flows, and a flow rate adjustment valve that adjusts the flow rate of the cooling water flowing through the cooling water passage,
The control device of the fuel separation system includes failure determination means for determining whether or not a failure has occurred in the fuel separation system, failure event determination means for determining a failure event based on a determination result of the failure determination means, Further comprising
The stop control means, when it is determined by the failure determination means that a failure has occurred in the fuel separation system, according to the determination result by the failure event determination means, the negative pressure pump, the fuel pump, and the Immediately stop the temperature-decreasing heat exchanger and immediately close the flow rate adjusting valve, or stop the negative pressure pump and close the flow rate adjusting valve, and then raise the temperature by the temperature-rising heat exchanger. The fuel pump and the temperature-decreasing heat exchanger are selected to be stopped when the temperature of the fuel that has been heated and flows into the separator falls below a predetermined temperature. 5. The control device for a fuel separation system according to any one of 5 above.

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