Chemistry: electrical current producing apparatus – product – and – With pressure equalizing means for liquid immersion operation
Reexamination Certificate
2000-11-17
2003-09-30
Kalafut, Stephen (Department: 1745)
Chemistry: electrical current producing apparatus, product, and
With pressure equalizing means for liquid immersion operation
C429S010000, C429S120000, C422S198000, C422S109000, C122S031100, C122S037000
Reexamination Certificate
active
06627342
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an evaporator liquid fuel injection apparatus and fuel cell system, and particularly it relates to an evaporator liquid fuel injection apparatus and fuel cell system whereby appropriate volumes of liquid fuel can be injected based on the requirements for a fuel cell-powered electric vehicle.
BACKGROUND OF THE INVENTION
Electric vehicles have become well known in recent years as vehicles driven by electrical power sources, and fuel cell-powered electric vehicles are being developed that employ fuel cells as the power source. Some fuel cells used in such fuel cell-powered electric vehicles employ so-called methanol-reformed fuel cells. In such fuel cells, a liquid fuel composed of a mixture of methanol and water, for example, is used and a fuel evaporator is provided which evaporates the liquid fuel and supplies it to a reformer.
The present applicant has disclosed a fuel evaporator for such types of fuel cells in the prior art in Japanese Patent Application No. Hei-1-125366. With reference to
FIG. 8
, the fuel evaporator
100
is provided with an evaporating chamber
110
wherein liquid fuel FL is evaporated by heated gas HG produced at a combustor (not illustrated) to produce fuel gas FG. The fuel gas FG produced at the evaporating chamber
110
is supplied to a superheating chamber
120
where it is superheated by heated gas HG exiting the evaporating chamber
110
. The evaporating chamber
110
and superheating chamber
120
are connected via a guide channel
130
formed along the floor side
110
A of the evaporating chamber
110
.
In the evaporating chamber
110
there are situated a plurality of U-shaped heat medium tubes
111
,
111
. . . through which heated gas HG passes, and the heated gas HG is conveyed toward the guide channel
130
. The liquid fuel FL is injected by the liquid fuel injection apparatus
140
toward the heat medium tubes
111
,
111
. . . in the evaporating chamber
110
. The liquid fuel FL injected by the liquid fuel injection apparatus
140
contacts with the heat medium tubes
111
,
111
. . . and undergoes heat exchange to be evaporated. The fuel gas FG produced by evaporation of the liquid fuel FL is supplied to a plurality of vapor tubes
121
,
121
. . . situated in the superheating chamber
120
.
Meanwhile, the heated gas HG flowing out from the heat medium tubes
111
,
111
. . . is supplied to the superheating chamber
120
via the guide channel
130
. In the superheating chamber
120
, the fuel gas FG passing through the vapor tubes
121
,
121
. . . is superheated by the heated gas HG supplied to the superheating chamber
120
. The superheated fuel gas FG then flows out from each of the vapor tubes
121
,
121
. . . and is supplied to a reformer (not illustrated).
Incidentally, since the pressure in the evaporating chamber varies depending on the effects of adjustment of the anode-cathode pressure difference in the fuel cell, it is difficult to maintain a constant pressure in the evaporating chamber. When liquid fuel is freely injected under conditions where the pressure in the evaporator is not constant, it becomes impossible for the liquid fuel to evenly spread in the evaporating chamber and the efficiency of the liquid fuel evaporation is reduced.
In the aforementioned conventional fuel evaporator
100
, however, no particular consideration is made to the relationship between the pressure in the evaporating chamber
110
and the injection volume of the liquid fuel. Consequently, the liquid fuel is simply injected in a volume based on the requirements of a fuel cell-powered electric vehicle.
On the other hand, fuel cell-powered electric vehicles sometimes require rapid huge current for the main motor for times of rapid acceleration and the like. In such situations it is desirable for the huge current to be supplied from the fuel cell as rapidly as possible, but supply of a huge current from the fuel cell requires a large volume of fuel gas. Production of a large volume of fuel gas requires injection of a large volume of liquid fuel and a large amount of heat for evaporation of the large volume of liquid fuel.
In the conventional fuel evaporator
100
described above, however, it is easy to inject a large volume of liquid fuel rapidly but it is not possible to supply a large amount of heat necessary to evaporate the liquid fuel. Consequently, the large volume of liquid fuel cannot be rapidly evaporated, and not only is it impossible to supply the fuel gas rapidly to the fuel cell, but this also results in liquid pools.
It is therefore an object of the present invention to allow efficient evaporation of liquid fuel by injection of a suitable amount of liquid fuel matching the requirements of fuel cells.
It is another object to achieve this even when huge current must be rapidly supplied in situations of rapid acceleration of fuel cell-powered electric vehicles, while also efficiently evaporating supplied liquid fuel and thus preventing liquid pools in the evaporating chamber.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided an evaporator liquid fuel injection apparatus for a fuel evaporator in a fuel cell system, having an evaporating chamber that evaporates liquid fuel with a high temperature heat medium into fuel gas, comprising:
a liquid fuel injection apparatus for injecting said liquid fuel into said evaporating chamber;
an injection volume adjusting apparatus for adjusting the injection volume of the liquid fuel injection apparatus; and
a fuel volume adjusting portion provided in said injection volume adjusting apparatus for setting the liquid fuel injection volume based on an injection volume target setting signal.
With such a construction, an injection volume adjusting portion is provided which sets the fuel injection volume based on an injection volume target setting signal. Consequently, since a suitable volume of liquid fuel can be injected to meet the requirements of the fuel cell, it is possible to efficiently evaporate the liquid fuel.
According to a second aspect of the invention, the aforementioned evaporator liquid fuel injection apparatus is characterized in that said fuel evaporator is provided with a pressure detection means for detecting the pressure in the evaporating chamber, and
said injection volume adjusting portion receives a command value from said pressure detection means and corrects said liquid fuel injection volume.
With such a construction, the pressure in the evaporator is detected by the pressure detection means and the fuel injection volume is corrected according to the command value from the pressure detection means. It is therefore possible to appropriately adjust the injection volume of the liquid fuel according to the pressure conditions in the evaporator. Consequently, the fuel injection volume can be appropriately adjusted even when fluctuations occur in the pressure inside the evaporator.
According to a third aspect of the invention, the aforementioned evaporator liquid fuel injection apparatus is characterized in that said fuel cell system is used in a fuel cell-powered electric vehicle, and
said injection volume target setting signal is an accelerator angle signal.
With such a construction, when the fuel cell system is used in a fuel cell-powered electric vehicle, the injection volume target setting signal is an accelerator angle signal. It is therefore possible to adjust the fuel injection volume according to the accelerator angle, which fluctuates with time in a fuel cell-powered electric vehicle.
According to a fourth aspect of the invention, the aforementioned evaporator liquid fuel injection apparatus is characterized in that said injection volume adjusting portion receives a residue signal from an energy buffer and corrects said liquid fuel injection volume.
With such a construction, the fuel injection volume is corrected by the energy buffer residue signal. In a fuel cell-powered electric vehicle, the required electric power load is supplied not only from the fuel cell but also from an
Miyano Kouji
Nakamura Masahito
Tachihara Takahiro
Alejandro R
Arent Fox Kinter Plotkin & Kahn PLLC
Honda Giken Kogyo Kabushiki Kaisha
Kalafut Stephen
LandOfFree
Evaporator liquid fuel injection apparatus and fuel cell system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Evaporator liquid fuel injection apparatus and fuel cell system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evaporator liquid fuel injection apparatus and fuel cell system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3014631