JPH07139725A - Combustion device - Google Patents

Abstract

PURPOSE:To provide a combustion device in which a processing capability of evaporated fuel is high under application of canister. CONSTITUTION:This combustion device 1 comprises a combustion chamber 10, a fuel tank 20 and a canister 30 having fuel adsorption agent 31. A surrounding atmosphere passage 63 for use in communicating between the canister 30 and the surrounding atmosphere is provided with a heat exchanger 40 for use in feeding discharged gas 83 of the combustion chamber 10. A first opening or closing valve 51 is inserted into a first passage 61 connecting the fuel tank 20 with the canister 30, a second opening or closing valve 52 is inserted into a second passage 62 for connecting the combustion chamber 10 with the canister, and a third opening or closing valve 53 is inserted into a surrounding atmosphere passage 63. It is preferable that the opening or closing valves 51 to 53 be properly opened or closed in response to the time of operation of the combustion chamber 10, a stopped state of the combustion chamber 10 and a supplementing of fuel to the fuel tank 20, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel type combustion apparatus used in a vehicle or the like, and more particularly to a combustion apparatus capable of efficiently purging adsorbed fuel in a canister.

[0002]

2. Description of the Related Art Recently, environmental protection has become a serious concern, and there is an increasing demand for suppression of evaporation and emission of vehicle fuel. Therefore, a canister is installed in the fuel tank,
Measures have been taken to prevent evaporative fuel in the tank from being leaked outside the vehicle by adsorbing it with an adsorbent. Then, the fuel adsorbed on the canister is purged again, and the fuel is burnt or the like.

On the other hand, a combustion type heater excellent in instant heat is used for heating a vehicle. This combustion heater pressurizes fuel oil supplied from a fuel tank, ejects it from a nozzle at a high speed, burns it, and exchanges the heat with the air in the passenger compartment to heat the inside of the passenger compartment. A canister is attached to the fuel tank, and the evaporated fuel generated in the empty part of the fuel tank is adsorbed by the canister. The canister is in communication with the atmosphere, and the adsorbed fuel is purged by ventilating the inflow by a blower or the like, and the exhaust of the canister containing the purged fuel is burned in the combustion chamber of the combustion heater.

[0004]

However, there are the following problems in the processing of the evaporated fuel in the conventional combustion apparatus having a canister. It is an inadequate ability to purge fuel through ventilation introduced into the canister.

If the fuel purging ability of the canister is low, the adsorbed fuel remains in the fuel adsorbent, and this residual fuel reduces the adsorbing power of the canister in the next cycle. As a result, the canister's ability to process evaporated fuel during repeated operation is reduced. In particular, the canister purge capacity decreases as the atmospheric temperature decreases, such as during winter. In view of the above conventional problems, the present invention aims to provide a combustion device which has a high adsorbability of evaporated fuel by a canister and a high purging ability thereof, and a small amount of evaporated fuel leaking to the outside.

[0006]

The present invention is a combustion apparatus having a combustion chamber, a fuel tank for supplying liquid fuel to the combustion chamber, and a canister for containing a fuel adsorbent, wherein the empty portion of the fuel tank is a canister. Through the canister, and the combustion chamber communicates with the atmosphere through the canister. On the other hand, the atmosphere passage that communicates the canister with the atmosphere is
A combustion apparatus is provided with a heat exchanger for introducing exhaust gas from a combustion chamber to warm the ventilation of the atmosphere passage.

What is most noticeable in the present invention is that a heat exchanger is attached to an air passage communicating between the canister and the atmosphere. The heat exchanger introduces the exhaust gas of the combustion chamber and vents the air passage. Is a heat exchanger that heats the. In the above description, the vacant part of the fuel tank is a part in the fuel tank that is not filled with fuel, such as the upper part of the fuel tank.

It is preferable that a first opening / closing valve is inserted in a first passage connecting the empty portion of the fuel tank and the canister, and the first opening / closing valve is opened only when fuel is supplied to the fuel tank. The reason is as follows. When fuel is supplied to the fuel tank, the fuel filler port is open and the fuel tank is in communication with the atmosphere, and there is a risk that the inside air of the empty space containing the evaporated fuel may leak to the outside. However, in the above configuration, at this time, the second opening / closing valve is open, and the canister and the fuel tank are in communication with each other, so that the inside air in the fuel tank enters the canister. Therefore, the evaporated fuel is adsorbed by the fuel adsorbent of the canister, and the evaporated fuel is suppressed from being discharged from the fuel tank to the atmosphere (evaporative emission).

It is more preferable to provide a blower or the like in the passage in order to promote the flow of ventilation from the fuel tank to the canister. Next, there is a case where the fuel is not supplied to the fuel tank. In this case, the fuel tank is closed and there is no possibility that the inside air of the fuel tank containing the evaporated fuel leaks to the outside. In this case, since the first opening / closing valve is closed, the adsorption of the canister does not promote the fuel evaporation in the fuel tank. Further, the adsorbed fuel can be purged from the canister, and the air inside the canister containing the adsorbed fuel can be introduced into the combustion chamber to burn the adsorbed fuel. At this time, in order to promote the flow of ventilation from the canister toward the combustion chamber, it is more preferable to install a blower or the like in the passage.

Further, in addition to the above-mentioned constitution in which the first opening / closing valve is provided, the second opening / closing valve is inserted in the second passage passing through the combustion chamber and the canister, and the third opening / closing valve is inserted in the atmosphere passage to perform the combustion operation. Occasionally, the first opening / closing valve is closed, the second and third opening / closing valves are opened, and when the combustion is stopped, all the first to third opening / closing valves are closed, and when the fuel is supplied to the fuel tank,
It is more preferable to open the third on-off valve and close the second on-off valve. The reason is as described below.

During the combustion operation of the combustion chamber, the first on-off valve is closed, the fuel tank and the canister are shut off, and the atmosphere and the canister are in communication (third on-off valve, open). . In addition, the canister and the combustion chamber are in communication (second
The on-off valve is open). Therefore, ventilation is introduced from the atmosphere into the canister, and this ventilation introduced into the canister is
It is introduced into the combustion chamber as canister exhaust containing adsorbed fuel purged from the canister. Then, the adsorbed fuel purged in the combustion chamber can be burnt.

Next, when combustion in the combustion chamber is stopped, all the first to third on-off valves are closed. Therefore, the evaporated fuel is not discharged to the atmosphere (evaporative emission) (third on-off valve, closed), and the exhaust of the canister containing the fuel is introduced into the stopped combustion chamber (first). (2 on-off valve, closed), and the problem that the canister adsorbs the evaporated fuel and thereby promotes fuel evaporation in the fuel tank (first on-off valve, closed) does not occur.

During refueling of the fuel tank, the first and third on-off valves are opened to form a flow path from the fuel tank to the atmosphere via the canister, so that the fuel vapor evaporated in the fuel tank is transferred to the canister. Can be adsorbed on. At the same time, by forming the flow path, it is possible to suppress evaporative emission that flows out from the cap of the fuel tank to the outside. It is more preferable to provide a blower or the like in the flow path in order to promote the flow of ventilation from the fuel tank to the atmosphere via the canister.

The second passage in the above structure may be branched from the middle of the first passage connecting the canister and the first opening / closing valve to communicate with the combustion chamber. The second on-off valve is inserted in the branch passage communicating with the combustion chamber. As mentioned above, the second
This is because if the passage is configured, a part of the first passage and the second passage becomes a common passage (between the canister and the branch point), so that the length of the passage becomes short and the number of pipe members can be reduced.

[0015]

In the combustion apparatus of the present invention, a heat exchanger is attached to the atmosphere passage that connects the canister and the atmosphere. Then, during the combustion operation of the combustion chamber, the atmosphere in the atmosphere passage can be warmed by introducing the exhaust gas into the heat exchanger. On the other hand, when the temperature of the ventilation introduced into the canister rises, the purging of the fuel adsorbed by the fuel adsorbent is further promoted. As a result, the amount of evaporated fuel that is introduced from the canister into the combustion chamber and burned is increased, while the purge amount is increased, so that the adsorption capacity of the regenerated fuel adsorbent is significantly improved. That is, both the adsorption capacity of the canister and the disposal capacity of the adsorbed fuel are improved, and the processing capacity of the evaporated fuel is greatly improved as a whole.

Further, since the heat energy of the exhaust gas of the combustion chamber is effectively used as the heat source of the heat exchanger, it is possible to construct a heat exchanger of extremely energy saving. As described above, according to the present invention, it is possible to provide a combustion device that has a high adsorbability and a purging ability of the evaporated fuel by the canister and that has a small amount of evaporated fuel leaking to the outside.

[0017]

【Example】

Example 1 A combustion apparatus according to an example of the present invention will be described with reference to FIGS. In this example, as shown in FIG.
0, the fuel tank 20 that supplies the liquid fuel 81 to the combustion chamber 10, and the canister 30 that stores the fuel adsorbent 31. Empty part 21 of the fuel tank 20
Communicate with the atmosphere portion 82 via the canister 30, and the combustion chamber 10 communicates with the atmosphere portion 82 via the canister 30. On the other hand, a heat exchanger 40 that introduces the exhaust gas 83 of the combustion chamber 10 and warms the ventilation of the atmosphere passage 63 is attached to the atmosphere passage 63 that connects the canister 30 and the atmosphere portion 82.

A first opening / closing valve 51 is provided in a first passage 61 connecting the empty portion 21 of the fuel tank 20 and the canister 30.
Is inserted, and the first on-off valve 51 opens only when fuel is supplied to the fuel tank 20. And combustion chamber 1
A second opening / closing valve 52 is inserted in a second passage 62 connecting 0 and the canister 30, and a third opening / closing valve 53 is inserted in the atmosphere passage 63.

When the combustion chamber 10 operates for combustion, the first
The on-off valve 51 is closed and the second and third on-off valves 52, 5
Open circuit 3. When the combustion in the combustion chamber is stopped, all the first to third on-off valves 51 to 53 are closed. When refueling the fuel tank 20 with the fuel 81, the first and third on-off valves 51 and 53 are opened and the second on-off valve 52 is closed regardless of the operating state of the combustion chamber 10.

Each of these will be described below. This example is a combustion device 1 for heating a vehicle. The combustion chamber 10 has an igniter (not shown) and a catalyst heater (not shown), and has a heat exchanger (not shown) for heating that exchanges heat with the air in the passenger compartment.

The exhaust passage 64 of the combustion chamber 10 communicates with the second atmosphere portion 821 via the heat exchanger 40. The heat exchanger 40 is attached to the atmosphere passage 63 of the canister 30 as shown in FIG. 2, and has a large number of fins 41 protruding into the atmosphere passage 63 as shown in FIG. The fin 41 is in contact with the ventilation 80 of the atmosphere passage 63 over a large area, and the heat transmitted from the exhaust gas 83 causes the ventilation 80 to flow.
To heat. Further, the exhaust passage 42 of the heat exchanger 40 spirally swirls the atmosphere passage 63 to efficiently transfer the heat energy of the exhaust gas 83. Reference numeral 4 in FIG.
3 is a passage wall of the exhaust passage 42.

On the other hand, as shown in FIG.
The other side 301 of the atmosphere passage 63 is connected to the vacant portion 21 of the fuel tank 20 through the first passage 61.
A first opening / closing valve 51 and a first blower 57 are inserted in the passage 61. Then, the first opening / closing valve 5 in the first passage 61
A branch passage 620 is formed from an intermediate position between 1 and the canister 30 and is connected to the combustion chamber 10. The second opening / closing valve 52 and the second blower 58 are inserted in the branch passage 620 that constitutes the second passage 62.

On the other hand, as shown in FIG. 1, the fuel tank 20 is a container having an airtight structure and has an oil supply port 22 for refueling. The fuel pump 23 is attached inside the fuel tank 20, and the fuel pump 23 is connected via the fuel pipe 231.
Are supplied to the combustion chamber 10.

The filling port 22 of the fuel tank 20 is shown in FIG.
When the fuel tank 20 is attached to the fuel tank 20, the air can flow only from the atmosphere into the inside (empty part 21) of the fuel tank 20. That is, a diaphragm 24 having one surface in contact with the atmosphere and the other surface in contact with the void portion 21, a communication passage 25 capable of communicating the void portion 21 with the atmosphere, and a communication passage 2 are provided above the fuel filler port 22.
5, a valve member 26 for opening and closing 5, a connecting member 261 for connecting the valve member 26 and the diaphragm, and a spring 262 for pressing the valve member 26 toward the atmosphere and closing the communication passage 25. ing.

When the internal pressure of the vacant portion 21 becomes lower than the atmospheric pressure, the deformation of the diaphragm 24 causes the connecting member 2 to be deformed.
By pushing down 61, the valve member 26 opens the communication passage 25. As a result, the outside air flows in and the inside of the fuel tank 20 can be constantly maintained at substantially atmospheric pressure, and the inside air of the fuel tank 20 does not flow outside. In FIG. 4, reference numeral 263 is an adjusting bolt for adjusting the strength of the spring 262.

Further, as shown in FIG. 1, the combustion chamber 10, the first to third on-off valves 51 to 53, the first and second blowers 57 and 5 are arranged.
8. The fuel pump 23 is electrically connected to an electronic control unit (ECU) 50, and the ECU 50 controls these members. Next, the control operation of the combustion device 1 using the ECU 50 and its operation will be described.

During the combustion operation of the combustion chamber 10, the fuel pump 23 operates and at the same time the second and third on-off valves 52,
53 is opened and the first on-off valve 51 is closed. And the second
The blower 58 is operated, and the canister 30 is discharged from the atmosphere portion 82.
A flow of aeration is generated to reach the combustion chamber 10 via. As a result, the ventilation that has flowed in from the atmosphere portion 82 is
It is possible to purge the fuel from the fuel adsorbent 31 and to flow into the combustion chamber 10 as a mixture containing the fuel, and burn the purged fuel in the combustion chamber 10.

On the other hand, the exhaust gas 83 of the combustion chamber 10 efficiently heats the above-mentioned ventilation through the atmosphere passage 63 in the heat exchanger 40. That is, as shown in FIGS. 2 and 3, the fins 4 of the heat exchanger 40 projecting toward the atmosphere passage 63.
1 heats the ventilation of the atmosphere passage 63.

Next, when combustion in the combustion chamber 10 is stopped, all the first to third on-off valves 51 to 53 are closed. As a result, all leakage of evaporated fuel generated from the canister 30 and the fuel tank 20 to the outside is blocked. When refueling the fuel tank 20, the second opening / closing valve 5
2 is closed and the first and third on-off valves 51 and 53 are opened.
At the same time, the first blower 57 is operated.

As a result, an air flow is generated from the empty space 21 of the fuel tank 20 through the canister 30 to the atmosphere space 82. Therefore, even if the refueling port 22 of the fuel tank 20 is opened, the outside air flows toward the vacant portion 21 of the fuel tank 20, and the air 83 in the vacant portion 21 containing the evaporated fuel is
It does not flow out from the fuel filler port 22.

The evaporated fuel in the empty space 21 of the fuel tank 20 is transferred to the fuel adsorbent 3 in the canister 30.
Adsorbed to 1. When the combustion chamber 10 during the combustion operation is stopped, the fuel pump 23 is stopped first, and after a slight delay time ΔT, the second and third on-off valves 52 and 53, the second blower 58, and Stop the catalyst heater. As a result, during the after purge time ΔT, the unburned gas remaining in the combustion chamber 10 immediately after extinguishing can react and burn when passing through the catalyst heater.

Next, the effect of the combustion apparatus 1 of this example will be described. In this example, the heat exchanger 40 is attached to the atmosphere passage 63 that connects the canister 30 and the atmosphere portion 82.
Therefore, the ventilation introduced into the canister 30 is heated,
The purging capability of the adsorbed fuel in the canister 30 is significantly increased. At the same time, the adsorption capacity of the regenerated canister 30 is increased, and the processing capacity of the canister can be remarkably improved.

Further, the heat exchanger 40 has an exhaust gas 83
Since it uses the above heat energy, it does not require any other heat power source and is a very energy-saving heat exchanger. Further, when the fuel filler port 22 is opened for refueling the fuel tank 20, the first blower 57 is operated and the fuel tank 2
Since an air flow is formed from the void portion 21 of 0 to the atmosphere portion 82 via the canister 30, the evaporative emission of the fuel tank 20 is adsorbed by the canister 30 and does not leak to the outside. As described above, according to the present example, it is possible to provide a combustion device that has a high adsorbability and a purging ability of the evaporated fuel by the canister and that has a very small amount of evaporated fuel leaking to the outside.

Embodiment 2 In this embodiment, as shown in FIG. 5, in Embodiment 1, one reversible blower 59 is used as the blower, and the blower 59 is connected to the branch point between the first passage 61 and the branch passage 620. 6
21 is another embodiment inserted between 21 and the canister 30. The blower 59 is a vane type blower capable of switching the flow of air in both forward and reverse directions.

The blower 59 forms an air flow from the canister 30 toward the combustion chamber 10 during the combustion operation of the combustion chamber 10, and reverses the direction of the air flow from the fuel tank 20 to the canister 30 during refueling of the fuel tank 20. Form an oncoming air stream. Others are the same as those in the first embodiment.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a combustion device according to a first embodiment.

FIG. 2 is a plan view of the heat exchanger according to the first embodiment.

FIG. 3 is a side view of FIG.

FIG. 4 is a front view of a fuel filler port of the fuel tank according to the first embodiment.

FIG. 5 is a configuration diagram of a combustion device according to a second embodiment.

[Explanation of symbols]

 1. ． ． Combustion device, 10. ． ． Combustion chamber, 20. ． ． Fuel tank, 30. ． ． Canister, 31. ． ． Fuel adsorbent, 40. ． ． Heat exchanger, 51-53. ． ． On-off valve, 61. ． ． First passage, 62. ． ． Second passage, 63. ． ． Atmosphere passage, 83. ． ． Exhaust gas,

Claims (4)

[Claims] 1. A combustion apparatus having a combustion chamber, a fuel tank for supplying liquid fuel to the combustion chamber, and a canister for containing a fuel adsorbent, wherein an empty portion of the fuel tank is connected to the atmosphere via the canister. The combustion chamber communicates with the atmosphere via a canister. On the other hand, the exhaust passage of the combustion chamber is introduced into the atmosphere passage communicating with the canister and the atmosphere to warm the ventilation of the atmosphere passage. A combustion device, which is equipped with a heat exchanger. 2. The first opening / closing valve according to claim 1, wherein a first opening / closing valve is inserted into a first passage connecting an empty portion of the fuel tank and a canister, and the first opening / closing valve supplies fuel to the fuel tank. A combustion device characterized by being opened only in case. 3. The second opening / closing valve according to claim 2, wherein a second opening / closing valve is inserted into the second passage connecting the combustion chamber and the canister, and a third opening / closing valve is inserted into the atmosphere passage, When the combustion chamber is in the combustion operation, the first on-off valve is closed and the second and third on-off valves are opened, and when the combustion of the combustion chamber is stopped, all of the first to third on-off valves are closed and the fuel is closed. When refueling a tank, a combustion device characterized by opening the first and third on-off valves and closing the second on-off valve regardless of the operating state of the combustion chamber. 4. The third passage according to claim 3, wherein the second passage branches from the middle of the first passage connecting the canister and the first opening / closing valve and communicates with the combustion chamber, and the second opening / closing valve is a combustion chamber. A combustion device inserted in the branch passage communicating with the chamber.