JP2000008982A - Fuel vapor recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To consume liquified fuel on an engine side, by liquifying fuel vapor from a fuel tank to be absorbed into the fuel in a condenser. SOLUTION: A condenser 3 is connected with a fuel tank 2 by a connection path K1, which is communicated with fuel L and has a cooling means 6. The condenser 3 comprises: a cooling tank 3a for storing the fuel L introduced and maintaining the fuel L at the same liquid level; a heat absorbing device 3b, which has a semiconductor element and a cooling fin, for cooling and cold-reserving the fuel L in the cooling tank 3a; a partition plate 3c splitting the cooling tank 3a; an inflow port 3d, into which fuel vapor is introduced, and which is provided on one side partitioned by the partition plate 3c in the cooling tank 3a; a fuel supply port 3e for supplying liquified fuel into which the fuel vapor is absorbed to an engine E side, and provided on the other side of the partition plate 3c in the cooling tank 3a; an exhaust port 3f for exhausting the remaining fuel vapor, which is not liquified and is not recovered, to a canister 4. In a case where a fuel amount in the cooling port 3a consumed by the engine E is larger than a fuel amount recovered by the condenser 3, the fuel is supplied from the fuel tank 2. In a case where a fuel amount in the cooling port 3a consumed by the engine E is smaller than a fuel amount recovered by the condenser 3, fuel is returned to the fuel tank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel vapor recovery apparatus for recovering and liquefying fuel vapor generated from a fuel tank of a vehicle or the like and consuming it by an engine.

[0002]

2. Description of the Related Art Conventionally, fuel vapor generated from a fuel tank of a vehicle or the like has been disclosed in FIG.
Has been put to practical use.

The fuel vapor recovery apparatus 100 temporarily absorbs, for example, a fuel vapor G (vapor) generated due to a rise in the temperature of the fuel L in a fuel tank 101 to an activated carbon 103a of a canister 103 through a ventilation path 102. Let me save.

[0004] A ventilation path 105 through a control valve 104 is provided so that the storage amount of the fuel vapor G in the activated carbon 103a does not exceed the adsorption capacity of the activated carbon 103a.
The fuel vapor G from the canister 103 is introduced into the intake pipe Ea by utilizing the suction negative pressure of the intake pipe Ea of the engine E, and is combusted by the engine E by a and 105b.

The discharge of the fuel vapor G from the canister 103 will be described in more detail. To be more specific, the canister 1 is opened through a vent opening (not shown) connected to the bottom of the canister 103.
03 canister 1 by air (gas) introduced inside
The fuel vapor G adsorbed and stored in the activated carbon 103a in the fuel cell 03 is scavenged (purged) and the control valve 1
04 while controlling the amount of gas introduced into the intake pipe Ea.
In the combustion chamber Eb.

[0006]

However, in such a fuel vapor recovery apparatus 100, the ventilation path 105
Although the amount of the air-fuel mixture introduced into the intake pipe Ea from the a and 105b is controlled by the control valve 104 into the intake pipe Ea, the fuel vapor G not measured accurately is not measured.
Since this is a mixture of (fuel component) and air, if this is added to the fuel component from the fuel injection valve that is accurately measured upstream of the intake pipe Ea, it is difficult to perform combustion at the set mixing ratio. Therefore, there is a concern that problems such as deterioration of the operating characteristics of the engine E and influence on the exhaust gas component may occur.

In addition, as fuel consumption is required to be reduced in response to recent environmental problems and resource saving, direct injection of fuel into a combustion chamber from conventional lean mixing ratio combustion (around 20 mixing ratios) is performed. If the super-lean mixture ratio combustion (mixing ratio of about 40 to 50) is attempted, the above-described problem may occur more remarkably.

[0008] On the other hand, under severe operating conditions such as traffic congestion under conditions of high outside air temperature such as in summer, the amount of fuel vapor evaporated from the fuel tank exceeds the adsorbed / stored amount of the canister and the scavenged amount. There is a possibility.

Further, in order to reduce fuel consumption, the vehicle is provided with both a system for stopping the engine when the vehicle stops at an intersection or the like, an engine (internal combustion engine) using fuel as a driving source of the vehicle, and an electric motor. In a hybrid system that selectively uses one or both of the engine and the electric motor according to the operating conditions of the vehicle, the engine is stopped and the vehicle is driven by the electric motor despite fuel evaporation from the fuel tank. It is impossible to scavenge (purge) the fuel vapor adsorbed and stored in the canister because it is burned by the engine, and even in this case, the generated fuel vapor may exceed the adsorption and storage amount of the canister There is also.

Therefore, in a system in which the fuel vapor G from the fuel tank 101 is first adsorbed by the canister 103, it is difficult to reduce the capacity of the canister 103 in consideration of the above problems.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to efficiently liquefy fuel vapor generated from a fuel tank so that it can be consumed on the engine side. It is another object of the present invention to provide a fuel vapor recovery device that does not release fuel vapor into the atmosphere even when the amount of generated fuel vapor is large.

[0012]

In order to achieve the above object, according to the present invention, a fuel is accommodated in a container and fuel vapor flowing from a fuel tank into the container is contained in the fuel inside the container. A path for supplying fuel from the container of the condensing means to the engine side, and a path for connecting the fuel tank and the container of the condensing means to allow fuel to flow therethrough. I do.

Thus, the fuel vapor from the fuel tank can be liquefied and absorbed in the fuel inside the container of the condenser, and the liquefied fuel can be consumed on the engine side.

Further, the fuel tank and the container of the condensing means may be arranged so that the liquid level of both fuels is the same, and the bottom of the container of the condensing means may be lower than the bottom of the fuel tank. preferable.

Thus, by supplying fuel to the engine from the inside of the container of the condensing means which is lower than the bottom of the fuel tank, the fuel in the fuel tank can be completely consumed.

It is also preferable that a cooling means is provided in a path for connecting the fuel tank and the container of the condensing means and allowing the fuel to pass therethrough.

Thus, the fuel can be cooled and delivered to the inside of the container of the condensing means, and the efficiency of condensing the fuel vapor can be improved.

[0018] The condensing means can also improve the efficiency of condensing the fuel vapor by providing means for miniaturizing the fuel vapor flowing into the container.

The condensing means is provided with a fuel vapor passage for extending the contact time and distance between the fuel and the fuel vapor, so that the efficiency of condensing the fuel vapor can be improved. The condensing means can also improve the efficiency of condensing fuel vapor by providing means for reducing the surface area of the liquid surface of the fuel in order to prevent vaporization of the fuel inside the container.

[0020] The condensing means can also improve the condensing efficiency of the fuel vapor by providing cooling means for cooling the fuel inside the container.

Further, the condensing means has an exhaust port for exhausting remaining fuel vapor not liquefied and recovered by the condensing means, and an inflow port for introducing fuel vapor from an exhaust port of the condenser; A canister having an adsorbing means for adsorbing the gas, a gas introduction port for introducing a gas for scavenging the fuel vapor adsorbed by the adsorbing means, an exhaust port for exhausting the scavenged fuel vapor, and an exhaust port of the canister Membrane separation means for separating the fuel vapor flowing from the air into an air component and a fuel vapor component by a separation membrane, and discharging the respective components from an air component discharge port and a fuel vapor component discharge port, and the air component of the membrane separation means. A scavenging circulation path formed by connecting a discharge port to a gas introduction port of the canister; A fuel vapor return path connecting the path for introducing fuel vapor into the discharge port and condenser, characterized in that it comprises a.

According to this configuration, the fuel vapor from the fuel tank is first condensed by the condenser and can be supplied to the engine side. Then, the fuel vapor that has not been condensed is once introduced into the canister, and then separated into a fuel component and an air component by the separation membrane of the membrane separation means. The air component in the membrane separation means is returned to the canister again by the scavenging circulation path, and the fuel vapor component is returned to the condenser again by the fuel vapor return path, thereby recovering the fuel vapor.

By providing a path for supplying the fuel vapor exhausted from the exhaust port of the canister to the engine side, the fuel vapor can be consumed on the engine side.

[0024]

(Embodiment 1) Hereinafter, the present invention will be described based on a first embodiment shown in FIG. The fuel vapor recovery device 1 according to the first embodiment of the present invention includes:
For example, the system has a configuration in which fuel vapor G generated from a fuel tank 2 provided in an automobile or the like using gasoline or light oil as fuel L is liquefied and can be consumed by an engine E. As shown in FIG. Components are:
It comprises a condenser 3, a canister 4, and a membrane separation means 5.

First, a description will be given of these components and the connection state between the components.

The fuel tank 2 is provided with a filler port 2a for supplying fuel, and the filler port 2a is normally closed by a filler cap 2b. 2c is a refueling cap 2
This is a refueling cap sensor that detects the opening and closing of b, and outputs detection information to control means described later.

An engine E is provided at the bottom inside the fuel tank 2.
2d is provided to a fuel supply path K3 for supplying fuel to a fuel injection device (not shown). A fuel supply pump (not shown) and the like are provided in the middle of the fuel supply path K3.

The condenser 3 is connected by a connection path K1 as a path for connecting the fuel tank 2 and the condenser 3 to communicate the fuel L, and the fuel L introduced from the fuel tank 2 is at the same liquid level position. Tank 3a as a container for storing
And a heat absorption device 3b having cooling fins and a semiconductor element (semiconductor thermoelectric conversion material) utilizing the Peltier effect, which functions as a cooling means for cooling and keeping the fuel L in the cooling tank 3a, and a cooling tank 3a. It has a configuration provided with a partition plate 3c.

The connection path K1 is provided with a cooling means 6, and since the temperature of the fuel L in the fuel tank 2 may rise, the fuel L sent to the condenser 3 is cooled (naturally). (Either cooling or forced cooling may be performed), thereby suppressing the temperature rise of the fuel L in the cooling tank 3a of the condenser 3.

An inlet port 3d connected to a passage K2 for introducing the fuel vapor G from the fuel tank 2 is provided on one side of the cooling tank 3a partitioned by the partition plate 3c, and the condenser 3 is provided on the other side. Liquefied and absorbed fuel pump 3p
A fuel supply port 3e connected to a fuel supply path K3 for supplying the fuel to the engine E side, and an exhaust port 3f for exhausting the remaining fuel vapor G that is not liquefied and recovered.

A path K2A is piped from the inflow port 3d to the vicinity of the bottom inside the cooling tank 3a, and a filter 3h for reducing bubbles of the discharged fuel vapor G is provided at the tip thereof.

The fuel L inside the cooling tank 3a of the condenser 3
Is provided with a temperature sensor 3g for detecting the temperature of the sensor, and inputs detection information to a control means C1 described later.

The canister 4 has an inlet port 4 connected to a path K4 for introducing the fuel vapor G from the condenser 3 into the container 4a.
b, activated carbon 4c as adsorbing means for adsorbing the inflowing fuel vapor G, and fuel vapor G adsorbed on the activated carbon 4c.
(In this embodiment, this gas is
A gas introduction port 4d for introducing the air which is the easiest to handle) and an exhaust port 4e for exhausting the fuel vapor G scavenged inside the container 4a.

In the vicinity of the gas introduction port 4d and the exhaust port 4e of the canister 4, HC sensors 4f and 4g for detecting HC (hydrocarbon) contained in the fuel vapor G as a fuel vapor sensor are provided.

In the membrane separation means 5, the air component Ga (the fuel vapor component Gl is reduced by the separation membrane 5a so that the fuel vapor G flowing in from the exhaust port 4e of the canister 4 via the path K5 is hardly contained. (Air) and a fuel vapor component Gl (high-concentration fuel vapor having a small amount of air component Ga), and each component can be discharged from the air component discharge port 5b and the fuel vapor component discharge port 5c.

The air component discharge port 5b of the membrane separation means 5 and the gas introduction port 4d of the canister 4 are connected by a path K6, and the air component Ga is returned to the canister 4. Therefore, a scavenging circulation path KR is formed from the canister 4 via the path K5 to the membrane separation means 5 and returns from the air component discharge port 5b of the membrane separation means 5 to the canister 4 via the path K6.

Note that a path K8 for supplying the fuel vapor G scavenged from the canister 4 to the engine E branches off from the path K5, so that the fuel vapor G can be consumed within a range that does not affect the combustion of the engine E. It has become.

A fuel vapor return path K7 connected to the inflow port 3d of the condenser 3 is connected to the fuel vapor component discharge port 5c, and the fuel vapor component Gl separated by the pump 7 is provided.
Is supplied to the condenser 3.

The operation of the fuel vapor recovery apparatus 1 having such a configuration will be described below. First, the fuel tank 2 is caused by a phenomenon such as an increase in the temperature of the fuel L inside the fuel tank 2.
The fuel vapor G generated inside passes through the path K2 and passes through the condenser 3
Will be introduced.

The cooling tank 3a of the condenser 3 is filled with the fuel L in the fuel tank 2 through the connection path K1, and the liquid level is similarly filled. Further, the fuel L is cooled and kept cool by the cooling means 6 and the heat absorbing device 3b.

The fuel vapor G is discharged into the cooled fuel L from the passage K2A as fine bubbles from the filter 3h, and is liquefied and absorbed into the fuel L.

Then, the fuel L in the cooling tank 3a is introduced into the fuel supply path K3 via the fuel supply port 3e by the pump 3p, and can be consumed by the engine E.

The cooling tank 3 consumed by the engine E
When the amount of the fuel L in the fuel cell a exceeds the amount of fuel that is liquefied / dissolved and recovered in the condenser 3, the fuel L is replenished from the fuel tank 2 via the connection path K1, and conversely. If the amount of fuel collected in step (1) exceeds the amount of consumption, the fuel L is returned to the fuel tank 2 via the connection path K1.

In order to enable the communication of the fuel L between the fuel tank 2 and the condenser 3, it is preferable to arrange the fuel tank 2 and the condenser 3 so that the liquid levels are the same. . Further, the bottom of the condenser 3 is made lower than the bottom of the fuel tank 2, and the fuel L is supplied from the lower part to the path K by the pump 3p.
3, the fuel L can be used up to the end.

When the fuel L consumed by the engine E can be supplied only through the path from the condenser 3, the fuel tank 2
It is also possible to omit the connection path between the path and the path K3.

In the fuel recovered by the condenser 3, the fuel vapor G is converted into low molecular components (C4 to C4) based on the boiling points of the components of the fuel L.
Because of the high content of C6 component, there is a tendency for low molecular components to increase, and fuel vapor G is also easily generated inside the condenser 3.

If the amount of fuel vapor G generated in the condenser 3 increases, the capacity of the canister 4 and the capacity of the membrane separation means 5 need to be increased in order to respond to the increase, and the capacity of the entire system needs to be increased. However, by preferentially consuming the fuel L containing a large amount of low molecular components in the condenser 3, the amount of the fuel vapor G generated in the condenser 3 is suppressed.

On the other hand, the portion of the fuel vapor G generated from the fuel tank 2 which has not been absorbed in the condenser 3 is supplied to the path K4.
Through the canister 4 to be adsorbed.

Therefore, the fuel vapor G generated from the fuel tank 2 is not directly introduced into the canister 4, but
Since only the amount not condensed and liquefied when passing through the condenser 3 is introduced, the capacity of the canister 4 can be set smaller than the method of directly introducing the fuel vapor G generated from the fuel tank 2. is there.

Further, when the fuel vapor G is introduced into the canister 4 and exceeds the adsorption capacity of the canister 4, the fuel vapor G overflows into the gas introduction port 4d below the canister 4.
This is detected by a hydrocarbon sensor 4f provided in the vicinity of the gas introduction port 4d, and circulates through the exhaust circulation path KR. In the exhaust circulation path KR, if necessary, the fuel vapor G or the air component Ga is circulated by a pump means (not shown) or the like.

When the exhaust circulation path KR circulates, the air and the air component G are supplied from the gas introduction port 4d below the canister 4.
Then, a is sucked, and the fuel vapor G adsorbed on the activated carbon 4c in the canister 4 is scavenged and enters the membrane separation means 5 through the path K5.

The air component Ga and the fuel vapor component Gl of the fuel vapor G are separated by the membrane separation means 5, and the air component Ga that does not permeate the membrane enters the canister 4 from the air component discharge port 5b through the path K6, and then passes through the path. It enters the membrane separation means 5 again from K5 (scavenging circulation path KR).

On the other hand, the fuel vapor component Gl that has passed through the membrane is sent out by the pump 7, enters the condenser 3 through the fuel vapor return paths K7 and K2A, and is again liquefied.

The fuel vapor G adsorbed on the activated carbon 4c in the canister 4 is scavenged from the canister 4 by repeating the above-described cycle, and when the fuel component concentration of the fuel vapor G in the path K5 decreases, the fuel vapor G near the exhaust port 4e. The hydrocarbon sensor 4g provided in the path K5 detects the concentration decrease and stops the scavenging circulation path KR and the pump 7.

After the engine is started, the condenser 3 may be operated by a temperature sensor 3g provided in the condenser 3 so as to maintain the required temperature.

Further, when fuel is supplied to the fuel tank 2, the fuel vapor G is not released to the atmosphere. Therefore, even when the engine is stopped, the fueling cap sensor 2c provided at the fueling port 2a of the fuel tank 2 opens and closes the fueling cap 2b. It is also possible to operate the fuel vapor recovery device 1 by sensing.

The fuel vapor recovery apparatus 1 as described above liquefies and recovers the fuel vapor G generated without being affected by the running state of the automobile (engine on / off) and the external environment (outside temperature, etc.). The fuel L can be supplied to the engine E and consumed.

Therefore, the fuel vapor G is directly transmitted to the engine E
Unlike the prior art fuel vapor recovery device that is supplied to the intake side of the engine E, it does not lower the operating characteristics of the engine E or affect the exhaust gas components.

Further, by various sensors and control means,
According to the state of generation of the fuel vapor G from the fuel tank 2 and the operation state of the device, the device is automatically operated or stopped, and the release of the fuel vapor G to the atmosphere can be completely prevented.

The fuel vapor G introduced into the canister 4
If there is no harm when the fuel is introduced into the intake side of the engine via a constant path K8 and provided with a control valve or the like, if necessary, the membrane separation means 5 and the pump are used. It is also possible to omit 7 and the like.

When it is necessary to set the flow direction of the fluid such as the fuel vapor G passing through each path to a predetermined direction, a check valve or the like may be appropriately interposed in the path. It is.

FIG. 2 is a circuit diagram schematically showing the connection between the components of the fuel vapor recovery device 1 and the control means C1. 2, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals.

Reference numerals 11a, 11b, 11c, and 11d denote switches for supplying current from the battery 12 to each control device, and include a cooling means 6, a pump 7, and a heat absorbing device 3, respectively.
Power is supplied to the semiconductor element b and the pump 3p.

The switches 11a to 11d are controlled by the signal paths 13a, 13b and 13 from the control means C1, respectively.
On / off control is performed by c and 13d.

Reference numeral 14 denotes an alarm lamp that lights when an abnormality occurs in the fuel vapor recovery device 1.

The control means C1 may be constituted by an electric circuit, may be provided with a CPU or a memory, and may be configured to process inputted information by software without any problem. It is also possible to adopt a configuration that is integrated into an attached engine control device.

The condenser 3 is provided with an engine start signal inputted to the control means C1 and a temperature sensor 3g provided in the condenser 3.
SW11c is activated / stopped by the determination of the control means C1 to control the temperature to a required temperature.

Further, even when the engine is stopped, the fuel tank 2
Can be controlled to operate and stop independently via the control means C1 by the signal of the refueling cap sensor 2c provided at the refueling port 2a. Thus, the generated fuel vapor can be suppressed.

The operation of the pump 7 is controlled as follows.

The HC sensor 4f enters the canister 4 from the condenser 3 and detects the concentration of the overflowed fuel vapor G, and sends a signal to the control means C1. The control means C1 makes a determination according to the input determination concentration and determines the SW1 of the pump 7
1b is operated, and the pump 7 starts operating.

When the concentration of the fuel vapor from the canister 4 decreases, the HC sensor 4g senses the concentration, and
A signal is sent to the control means C1. The control means C1 makes a determination in accordance with the input determination concentration, and
And the pump 7 stops.

The control of the cooling means 6 and the pump 3p can be controlled, for example, to be ON when the start of the engine is confirmed.

Therefore, the control means C1 controls the driving of the fuel vapor recovery apparatus 1 appropriately in accordance with the detected operating state of each component, thereby reducing the power consumption due to the intermittent operation of the fuel vapor recovery apparatus 1. It is possible to reduce the temperature, to improve the condensation efficiency by maintaining the temperature of the fuel L inside the condenser 3 at an appropriate temperature, to shorten the scavenging time of the canister 4, and the like.

When an abnormality occurs in each sensor or unit, an alarm lamp 14 provided in the driver's seat can be turned on as an abnormality of the device.

For example, means for measuring the time from the start of the operation of the scavenging circulation path KR to the end of the operation is provided inside the control means C1, so that the scavenging circulation path KR can be operated even after a predetermined time has elapsed from the start of the operation. If the operation is continued without terminating the operation, it is considered that the apparatus is determined to be abnormal and the alarm lamp 14 provided in the driver's seat or the like is turned on.

Further, instead of the HC sensor, a load sensor for detecting the weight of the fuel vapor G stored in the activated carbon 4c, a load sensor for detecting the weight of the fuel vapor G stored in the activated carbon 4c, It is also possible to provide a resistance sensor that measures the change and detects the amount of the accumulated fuel vapor G, and the operation of the scavenging circulation path KR and the pump 7 can be controlled by these sensors.

In this case, for example, when the maximum storage amount of the fuel vapor G by the activated carbon 4c reaches 70%, the operation of the scavenging circulation path KR and the pump 7 is started, and when the maximum storage amount of the fuel vapor G decreases to 20% of the maximum storage amount. Scavenging circulation path KR and pump 7
It is also possible to control to stop the operation of.

(Embodiment 2) FIG. 3 is a diagram schematically showing, as a second embodiment, an improved example of the configuration of the condenser 3 for efficiently recovering the fuel vapor G.

The method of bubbling the fuel vapor G in the condenser 3 to condense the fuel vapor G is a method of cooling the fuel vapor G by contacting it with cooling fins or the like. It has been confirmed by experiments that the amount of condensation is greater than that of the transfer.

This is a method of bubbling the fuel vapor G in the fuel L and condensing it.
It is explained by the fact that a large amount of dissolution (dissolution phenomenon) is contained.

Therefore, promoting this dissolution phenomenon makes it possible to increase the efficiency of recovering the fuel vapor G.

Further, as described in the first embodiment, the condenser 3 is forcibly cooled by using the heat absorbing device 3b to cool the fuel L in the cooling tank 3a. Although the temperature of the fuel L decreases and the cooling efficiency improves, when the fuel vapor recovery device 1 is used for a vehicle, the capacity of the battery and the time when the battery is turned off (when the engine E is stopped or the vehicle is stopped, etc.) are required. In consideration of this, the recovery rate of the fuel vapor G slightly decreases, but it is also important to make the fuel vapor recovery apparatus 1 operable without the heat absorbing device 3b or to improve the recovery efficiency.

FIGS. 3 (b) to 3 (d) show that the fuel vapor G is provided with a finer means to promote the melting phenomenon,
Compared to the configuration (a), more fuel vapor G is condensed and liquefied by the fuel L in the cooling tank 3a.

In the condenser shown in FIG. 3, the connection path K1, which is connected to the cooling tank 3a, the fuel supply port 3e, the exhaust port 3f
The illustration of such a configuration is omitted.

In the configuration shown in FIG. 3A, a path K2A is provided in the cooling tank 3a, and the fuel vapor G is discharged (bubbled) from the tip thereof.

In the configuration shown in FIG. 3 (b), a filter 3h (meaning means for miniaturizing the fuel vapor) is provided at the end of the path K2A to make the bubbles of the fuel vapor G discharged fine.

The filter 3h is a bubble-dispersing filter made of a material having durability against fuel (gasoline or the like) such as ceramics, polypropylene, and polyethylene. As an experimental example, a sintered filter of polypropylene (pore diameter: 50, 150, 300 μm) and the fuel vapor G
As a result, the recovery rate (liquefaction rate) of the fuel vapor G is improved as compared with the configuration having no filter.

The table of FIG. 4 shows the result of measuring the recovery rate of the fuel vapor G for each sample (Nos. 1 to 9) with changed conditions.

The conditions of the sample are as shown in FIG. 5. Bubbling is common to all the samples, and other conditions include the presence or absence of the cooling means, the presence or absence of the filter and the size of the pore diameter. changed.

As a result, a filter (Gr.
C) is compared with the case without the filter (Gr. B).
The recovery rate (liquefaction rate) of the fuel vapor G was improved by about 6%.

In the configuration of FIG. 3C, the height of the cooling tank 3a is set to satisfy H1 <H2 in order to increase the contact time and distance between the fuel vapor G and the fuel L as compared with FIG. 3A. And a long fuel vapor passage.

In order to confirm the effect of the configuration shown in FIG. 3C, the capacity of the condenser cooling tank was set to 0.75 l, the height of the liquid level was set to 95 mm, and the capacity of the condenser cooling tank was set to 95 mm. 1.5
l, the height of the liquid surface is 150 mm (Gr.
Compared with A), the former (with a capacity of 0.75 l)
The recovery rate when the cooling means is not operated (or no cooling means) is about 40%, whereas the recovery rate of the latter (with 1.5 liter capacity) is about 60% and about 10-20%.
% Recovery could be improved. However, the recovery rate fluctuates somewhat due to the influence of the environmental temperature in which the apparatus is installed.

FIG. 7 schematically shows a cross-sectional structure of a condenser having a structure in which the fuel vapor passage in the cooling tank 3a is lengthened.
The condenser is not limited to this configuration, and other configurations having a horizontal component bent from the vertical direction in the fuel vapor passage can be applied.

In order to lengthen the fuel vapor passage,
The inside of the cooling tank 3a is formed in a zigzag shape (FIG. 7 (a)), a spiral shape (FIG. 7 (b)), or at least one with a hole.
With a configuration in which the fuel vapor G passes through at least one partition plate (FIG. 7 (c)) or the like, the substantial contact time and distance between the fuel L and the fuel vapor G can be further increased. is there. In the condenser of FIG. 7, a fuel vapor passage path is indicated by an arrow, and a connection path K1, a fuel supply port 3e, an exhaust port 3f, and the like connected to the cooling tank 3a are not shown.

In the configuration of FIG. 3D, in addition to the configuration of FIG. 3C, stirring means 3m for stirring the fuel in the cooling tank 3a is used.
(Means for refining fuel vapor).

In the configuration shown in FIG. 3D, the fuel vapor G discharged by bubbling is agitated by the agitating means 3m, so that the substantial contact time and distance between the fuel L and the fuel vapor G can be increased. It is possible to improve the recovery rate (liquefaction rate) of the fuel vapor G by about several percent.

(Embodiment 3) FIG. 6 is a diagram schematically showing another improved example of the configuration of the condenser 3 for efficiently recovering the fuel vapor G as a third embodiment. is there.

In the condenser of FIG. 6, a connection path K1 connected to the cooling tank 3a, a fuel supply port 3e, an exhaust port 3f
The illustration of such a configuration is omitted.

In the third embodiment, a means for reducing the surface area of the liquid surface is provided for the purpose of suppressing the evaporation of the fuel L from the liquid surface in the cooling tank 3a.

In the configuration shown in FIG. 6A, the upper portion 3n of the cooling tank 3a has a small cross-sectional area, and the liquid surface has a small cross-sectional area.
By locating at n, the surface area of the liquid level of the fuel L can be reduced and evaporation from the liquid level can be suppressed.

In the configuration shown in FIG. 6B, a sheet-like float 3q is floated on the liquid surface of the fuel L.

In the configuration shown in FIG. 6C, a ball-shaped float 3r is floated on the liquid surface of the fuel L.

In the configuration shown in FIG. 6D, a member 3s having a small cross-sectional area is arranged above the cooling tank 3a.

As described above, the recovery rate (liquefaction rate) of the fuel vapor G evaporating from the surface of the condenser 3 can be improved by means for reducing the surface area of various liquid levels.

That is, the recovery rate (liquefaction rate) of the fuel vapor G can be improved by several% by reducing the surface area of the liquid surface of the fuel in the condenser 3 containing a large amount of low molecular components which are easily evaporated. It is.

The present means for reducing the surface area is used when the fuel vapor G is generated from the condenser 3 when the vehicle is stopped (engine OF
This is particularly effective when the proportion of vapor generated from the surface is larger than the vapor generated by bubbling from the filter, such as when the vehicle is left unattended.

FIG. 8 is a table showing the results of measuring the amount of evaporation of the fuel vapor G generated from the same fuel L obtained through a different process (once vaporized and then condensed).

In FIG. 8, three types of fuel are used. That is, a gasoline stock solution (corresponding to the fuel in the fuel tank 2) and a fuel of a low molecular component obtained by condensing fuel vapor evaporated from the gasoline stock solution by a cooling means such as a Peltier element (fuel vapor stored in the condenser 3) Equivalent to)
And a fuel obtained by cooling and condensing components not liquefied by the condenser (corresponding to fuel adsorbed by the canister 4).

In the measurement, the surface area of the liquid level of the contained fuel is 1
The above-mentioned fuel is put into a container having a size of 00 cm ² (open at the top), and the amount of evaporation at a constant environmental temperature (28 ° C.) is measured. From the result of this measurement, the amount of evaporation from the fuel containing a large amount of low molecular components (C4, C5, C6 components) evaporated from the gasoline stock solution (corresponding to the amount of evaporation from the condenser 3) is calculated as the evaporation amount from the gasoline stock solution ( (Equivalent to the amount of evaporation from fuel tank 2)
The evaporation amount is about 2.5 times (40 g for 15 g) as compared with.

Therefore, reducing the surface area of the liquid surface of the condenser 3 is effective for suppressing the amount of evaporation from the condenser 3 and is an important method.

[0111]

According to the present invention described above, the fuel vapor generated from the fuel tank can be liquefied and consumed on the engine side. Therefore, the operating characteristics of the engine can be improved by reducing or eliminating the amount of fuel vapor introduced into the intake side of the engine,
Further, release of fuel vapor into the atmosphere is prevented.

By supplying the fuel to the engine side from the position inside the container of the condensing means which is lower than the bottom of the fuel tank, the fuel in the fuel tank can be completely consumed.

By sending the cooled fuel to the inside of the container of the condensing means, the efficiency of condensing the fuel vapor can be improved.

The condensing means is also provided with means for miniaturizing the fuel vapor flowing into the inside of the container, or a fuel vapor passage for increasing the contact time and distance between the fuel and the fuel vapor. Can be improved.

The condensing means is provided with a fuel vapor passage for extending the contact time and distance between the fuel and the fuel vapor, so that the efficiency of condensing the fuel vapor can be improved. The condensing means can also improve the efficiency of condensing fuel vapor by providing means for reducing the surface area of the liquid surface of the fuel in order to prevent vaporization of the fuel inside the container.

The condensing means is provided with a cooling means for cooling the fuel in the container, so that the condensing efficiency of the fuel vapor can be improved.

By providing the canister and the membrane separating means in addition to the condensing means, the fuel vapor not condensed by the condensing means can be liquefied and collected.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of a fuel vapor recovery device according to a first embodiment.

FIG. 2 is an explanatory diagram of a circuit configuration of control means of the fuel vapor recovery device according to the first embodiment.

FIG. 3 is a configuration explanatory view of a condenser according to a second embodiment.

FIG. 4 is a table showing measurement results of a recovery rate of fuel vapor for each sample.

FIG. 5 is a table showing experimental conditions and results of measurement of the recovery rate of fuel vapor for each sample.

FIG. 6 is a diagram illustrating a configuration of a condenser according to a third embodiment.

FIG. 7 is an explanatory diagram of a configuration of a condenser according to a second embodiment.

FIG. 8 is a table showing the results of measuring the amount of evaporation of fuel vapor generated from fuel obtained through different processes.

FIG. 9 is a configuration explanatory view of a conventional fuel vapor recovery device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fuel vapor recovery device 2 fuel tank 2 a filler port 2 b filler cap 2 c filler cap sensor 2 d suction unit 3 condenser 3 a cooling tank (container) 3 b heat absorber 3 c partition plate 3 d inflow port 3 e fuel supply port 3 f exhaust port 3 g temperature sensor 3h filter 3p pump 4 canister 4a container 4b inflow port 4c activated carbon (adsorption means) 4d gas introduction port 4e exhaust port 4f, 4g HC sensor (fuel vapor sensor) 5 membrane separation means 5a separation membrane 5b air component discharge port 5c fuel vapor component Discharge port 6 Cooling means 7 Pump 11a, 11b, 11c, 11d Switch 12 Battery 13a, 13b, 13c, 13d Signal path 14 Alarm lamp C1 Control means E Engine G Fuel vapor Ga Air component Gl Fuel vapor component K1 Connection K2, K2A, K4, K5, K6, K8 path K3 fuel supply passage K7 fuel vapor return path KR scavenging circulation path L fuel

Claims (9)

[Claims] 1. A condensing means for accommodating a fuel in a container and condensing fuel vapor flowing into the container from a fuel tank into the fuel in the container; and supplying the fuel from the container of the condensing means to the engine side. A fuel vapor recovery device, comprising: a supply path; and a path for connecting the fuel tank and a container of the condensing means to allow fuel to pass therethrough. 2. The fuel tank and the container of the condensing means are arranged so that the liquid level of both fuels is the same, and the bottom of the container of the condensing means is lower than the bottom of the fuel tank. The fuel vapor recovery device according to claim 1, wherein: 3. The fuel vapor recovery device according to claim 1, wherein a cooling unit is provided in a path for connecting the fuel tank and a container of the condensing unit to communicate the fuel. 4. The apparatus according to claim 1, wherein said condensing means includes means for miniaturizing fuel vapor flowing into the container.
The fuel vapor recovery device according to any one of claims 1 to 3. 5. The condensing means according to claim 1, further comprising a fuel vapor passage for increasing a contact time and a distance between the fuel and the fuel vapor. Fuel vapor recovery device. 6. The condensing means according to claim 1, further comprising means for reducing a surface area of a liquid surface of the fuel in order to prevent vaporization of the fuel inside the container. The fuel vapor recovery device according to any one of the preceding claims. 7. The condensing means includes a cooling means for cooling the fuel inside the container.
The fuel vapor recovery device according to any one of the preceding claims. 8. The condensing means has an exhaust port for exhausting remaining fuel vapor not liquefied and recovered by the condensing means, an inflow port for introducing fuel vapor from an exhaust port of the condenser, and an inflowing fuel vapor. A canister provided with an adsorbing means for adsorbing gas, a gas introduction port for introducing a gas for scavenging the fuel vapor adsorbed by the adsorbing means, an exhaust port for exhausting the scavenged fuel vapor, and an exhaust port of the canister Membrane separation means for separating fuel vapor flowing from the air into an air component and a fuel vapor component by a separation membrane, and discharging each component from an air component discharge port and a fuel vapor component discharge port, and the air component of the membrane separation means. A scavenging circulation path formed by connecting a discharge port and a gas introduction port of the canister; and a fuel vapor component of the membrane separation means. Any of claims 1 to 7 and the fuel vapor return path connecting the path for introducing fuel vapor into the port and the condenser exit, characterized in that it comprises for 1
A fuel vapor recovery device according to the item. 9. The fuel vapor recovery device according to claim 8, further comprising a path for supplying fuel vapor exhausted from an exhaust port of the canister to an engine side.