U.S. patent application number 12/797257 was filed with the patent office on 2011-12-15 for microcondenser device.
This patent application is currently assigned to HONDA MOTOR CO., LTD.. Invention is credited to Dennis B. Chung.
Application Number | 20110303197 12/797257 |
Document ID | / |
Family ID | 45095208 |
Filed Date | 2011-12-15 |
United States Patent
Application |
20110303197 |
Kind Code |
A1 |
Chung; Dennis B. |
December 15, 2011 |
MICROCONDENSER DEVICE
Abstract
A microcondenser device for an evaporative emission control
system associated with an internal combustion engine includes a
housing having a lower wall and at least one side wall extending
upward from the lower wall. The lower wall and the at least one
side wall together defining a chamber in the housing. A
thermoelectric element is supported by the at least one side wall
in spaced relation relative to the lower wall. An inlet is defined
in the housing for admitting fuel vapor into the chamber. A
condensation outlet is defined in the housing for discharging
liquid fuel that is condensed from the fuel vapor in the chamber. A
porous heat sink element is received in the chamber for absorbing
the fuel vapor admitted through the inlet. The porous heat sink
element is in conductive thermal contact with the thermoelectric
element.
Inventors: |
Chung; Dennis B.; (Dublin,
OH) |
Assignee: |
HONDA MOTOR CO., LTD.
Tokyo
JP
|
Family ID: |
45095208 |
Appl. No.: |
12/797257 |
Filed: |
June 9, 2010 |
Current U.S.
Class: |
123/518 |
Current CPC
Class: |
Y02T 10/126 20130101;
F02M 33/02 20130101; B01D 2259/4516 20130101; H01L 35/00 20130101;
B01D 53/002 20130101; F02M 25/0854 20130101; H01L 35/30 20130101;
B01D 53/0407 20130101; F02M 2025/0863 20130101; F02M 31/20
20130101; Y02T 10/12 20130101; B60K 2015/03514 20130101; Y02T
10/166 20130101; B60K 15/03504 20130101; F02M 33/08 20130101 |
Class at
Publication: |
123/518 |
International
Class: |
F02M 33/02 20060101
F02M033/02 |
Claims
1. A microcondenser device for an evaporative emission control
system associated with an internal combustion engine, comprising: a
housing having a lower wall and at least one side wall extending
upward from the lower wall, the lower wall and the at least one
side wall together define a chamber in the housing; a
thermoelectric element supported by the at least one side wall in
spaced relation relative to the lower wall; an inlet defined in the
housing for admitting fuel vapor into the chamber; a condensation
outlet defined in the housing for discharging liquid fuel that is
condensed from the fuel vapor in the chamber; and a porous heat
sink element received in the chamber for absorbing the fuel vapor
admitted through the inlet, the porous heat sink element in
conductive thermal contact with the thermoelectric element.
2. The microcondenser device of claim 1 further including at least
one support baffle supporting the porous heat sink element in an
elevated position from the lower wall and in conductive thermal
contact with the thermoelectric element.
3. The microcondenser device of claim 1 wherein the porous heat
sink element is a carbon foam element having a varying
porosity.
4. The microcondenser device of claim 1 further including a vapor
outlet defined in the housing for discharging uncondensed fuel
vapor, the vapor outlet elevated relative to the inlet and the
inlet elevated relative to the condensation outlet.
5. The microcondenser device of claim 1 further including a heat
pipe or a liquid cooling circuit for removing heat from the
thermoelectric element.
6. A microcondenser device for an evaporative emission control
system, comprising: a housing having an inlet for receiving fuel
vapor and a condensation outlet for discharging condensed fuel
vapor; a porous heat sink element disposed in the housing and
fluidly interposed between the inlet and the condensation outlet
for absorbing the fuel vapor received through the inlet; a
thermoelectric element in thermal contact with the porous heat sink
element for removing heat from the fuel vapor absorbed by the
porous heat sink element to condense the fuel vapor; and at least
one support baffle supporting the porous heat sink element within
the housing.
7. The microcondenser device of claim 6 wherein the porous heat
sink element is a carbon foam heat sink element.
8. The microcondenser device of claim 6 wherein the housing has a
vapor outlet for discharging fuel vapor that remains vaporized
after passing through the porous heat sink element, the porous heat
sink element fluidly interposed between the inlet and the vapor
outlet.
9. The microcondenser device of claim 8 wherein the housing
includes a bottom wall and at least one side wall extending upward
from the bottom wall, the thermoelectric element is spaced apart
vertically from the bottom wall, the at least one support baffle
supports the porous heat sink element in spaced apart relation from
the bottom wall.
10. The microcondenser device of claim 9 wherein the at least one
support baffle urges the porous heat sink element toward the
thermoelectric element.
11. The microcondenser device of claim 9 wherein the at least one
support baffle urges the porous heat sink element into thermal
contact with the thermoelectric element.
12. The microcondenser device of claim 9 wherein a plenum chamber
is formed by the at least one side wall, the at least one support
baffle and the porous heat sink element, the plenum chamber
extending along substantially an entire width of the porous heat
sink element.
13. The microcondenser device of claim 12 wherein the porous heat
sink element has an increased porosity adjacent the plenum
chamber.
14. The microcondenser device of claim 9 wherein the porous heat
sink element has an increased porosity adjacent a first side of the
porous heat sink element disposed adjacent the inlet than a second
side adjacent the vapor outlet.
15. The microcondenser device of claim 14 wherein the porous heat
sink element has an increased porosity adjacent an underside of the
porous heat sink element disposed adjacent the condensation outlet
than an upper side adjacent the thermoelectric element.
16. The microcondenser device of claim 9 wherein the porous heat
sink element has an increased porosity adjacent an underside of the
porous heat sink element disposed adjacent the condensation outlet
than an upper side adjacent the thermoelectric element.
17. The microcondenser device of claim 6 wherein the thermoelectric
element is nestably received within a recess defined in the
housing.
18. The microcondenser device of claim 17 wherein the housing
includes a bottom wall and at least one side wall extending upward
from the bottom wall, the at least one side wall includes a recess
defined by a shoulder and face extending upward from the shoulder,
the thermoelectric element supported on the shoulder and sized such
that at least one peripheral edge of the thermoelectric element is
positioned closely adjacent the face.
19. The microcondenser device of claim 18 wherein a copper plate is
interposed between the porous heat sink element and the
thermoelectric element.
20. The microcondenser device of claim 1 wherein a copper plate is
interposed between the porous heat sink element and the
thermoelectric element.
21. The microcondenser device of claim 20 wherein a thermal paste
is interposed between at least one of: the copper plate and the
thermoelectric element or the copper plate and the porous heat sink
element.
22. The microcondenser device of claim 6 wherein the porous heat
sink element has an increased porosity adjacent the inlet than
adjacent the condensation outlet.
23. The microcondenser device of claim 6 wherein the housing is
formed of a plastic material.
24. The microcondenser device of claim 6 wherein an insulating
layer is disposed one of: around an exterior of the housing or
inside the housing around the porous heat sink element.
25. The microcondenser of claim 6 further including a heat removal
assembly for removing heat from a hot side of the microcondenser
element, the heat removal assembly comprising at least one of: a
heat pipe or a liquid cooling circuit.
26. A microcondenser device for an evaporative emission control
system, comprising: a housing having an inlet for receiving fuel
vapor and a condensation outlet for discharging condensed fuel
vapor; a porous heat sink element disposed in the housing and
fluidly interposed between the inlet and the condensation outlet
for absorbing the fuel vapor received through the inlet; a
thermoelectric element in thermal contact with the porous heat sink
element for removing heat from the fuel vapor absorbed by the
porous heat sink element to condense the fuel vapor; and a heat
removal assembly in conductive thermal contact with a hot side of
the microcondenser element for removing heat therefrom, the heat
removal assembly comprising at least one of: a heat pipe or a
liquid cooling circuit.
Description
BACKGROUND
[0001] The present disclosure generally relates to evaporative
emission control systems for internal combustion engines, and more
particularly relates to a microcondenser device for an evaporative
emission control system associated with an internal combustion
engine.
[0002] Conventional vehicle fuel systems associated with internal
combustion engines typically employ a fuel canister for receiving
fuel vapor from a vehicle's fuel tank. The fuel canister is adapted
to temporarily retain the received vapor therein to prevent it from
being released to the atmosphere. More particularly, fuel vapor can
enter the fuel canister from the fuel tank wherein the fuel vapor
is absorbed and retained in a carbon bed of the fuel canister.
Typically, the retention of the displaced fuel vapor within the
fuel canister is only temporary as the fuel vapor retained in the
fuel canister is periodically purged to allow the canister to
accommodate and absorb additional fuel vapor from the fuel tank.
During such purging, the fuel vapor captured by the canister can be
sent to the vehicle's engine, and particularly to an induction
system of the engine, for combustion.
[0003] Various other systems have been proposed to more strictly
control containment of fuel vapors and/or improve vehicle
efficiency by controlling fuel vapor processing. For example, some
systems include a bladder disposed in the vehicle's fuel tank that
expands and contracts to control fuel vapor. A pump can be used in
association with the bladder for applying pressure to the walls of
the bladder. The pressure is applied for purposes of forcing the
bladder walls against the fuel contained therein to prevent or
limit vapor formation. A fuel canister, as described in the
preceding paragraph, can optionally be used in the bladder fuel
system for capturing fuel vapor that forms despite the use of the
bladder.
[0004] Also known is a canisterless evaporative emission control
system for an internal combustion engine. One particular known
system includes a fuel tank wherein vaporized fuel is generated and
a microcondenser device for processing the vaporized fuel received
from the fuel tank. The microcondenser device has a heat sink
portion formed of carbon foam in thermal communication with a
thermoelectric element for removing heat from the heat sink
portion. The fuel vapor is processed by passing the fuel vapor
through the heat sink portion to remove heat therefrom and condense
at least a portion of the fuel vapor to liquid fuel. Drawbacks of
this known canisterless control system include significant power
consumption requirements for the thermoelectric element and a
significant volume of uncondensed fuel vapor passing through the
microcondenser device.
SUMMARY
[0005] According to one aspect, a microcondenser device is provided
for an evaporative emission control system associated with an
internal combustion engine. The device includes a housing having a
lower wall and at least one side wall extending upward from the
lower wall. The lower wall and the at least one side wall together
define a chamber in the housing. A thermoelectric element is
supported by the at least one side wall in spaced relation relative
to the lower wall. An inlet is defined in the housing for admitting
fuel vapor into the chamber. A condensation outlet is defined in
the housing for discharging liquid fuel that is condensed from the
fuel vapor in the chamber. A porous heat sink element is received
in the chamber for absorbing the fuel vapor admitted through the
inlet. The porous heat sink element is in conductive thermal
contact with the thermoelectric element.
[0006] According to another aspect, a microcondenser device for an
evaporative emission control system includes a housing having an
inlet for receiving fuel vapor and a condensation outlet for
discharging condensed fuel vapor. A porous heat sink element is
disposed in the housing and fluidly interposed between the inlet
and the condensation outlet for absorbing the fuel vapor received
through the inlet. A thermoelectric element is in thermal contact
with the thermal heat sink element for removing heat from the fuel
vapor absorbed by the porous heat sink element to condense the fuel
vapor. At least one support baffle supports the porous heat sink
element within the housing.
[0007] According to a further aspect, a microcondenser device for
an evaporative emission control system includes a housing having an
inlet for receiving fuel vapor and a condensation outlet for
discharging condensed fuel vapor. A porous heat sink element is
disposed in the housing and is fluidly interposed between the inlet
and the condensation outlet for absorbing the fuel vapor received
through the inlet. A thermoelectric element is in thermal contact
with the porous heat sink element for removing heat from the fuel
vapor absorbed by the porous heat sink element to condense the fuel
vapor. A heat removal assembly is in conductive thermal contact
with a hot side of the microcondenser element for removing heat
therefrom. The heat removal assembly comprises at least one of: a
heat pipe or a liquid cooling circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic view of an evaporative emission
control system having a microcondenser device for processing fuel
vapor.
[0009] FIG. 2 is a perspective view, partially in cross-section, of
the microcondenser device.
[0010] FIG. 3 is an elevational cross-section view of the
microcondenser device.
[0011] FIG. 4 is plan cross-section view of the microcondenser
device.
[0012] FIG. 5 is an elevational cross-section view of a
microcondenser device according to an alternate embodiment.
[0013] FIG. 6 is a plan cross-section view of the microcondenser
device of FIG. 5.
[0014] FIG. 7 is an elevational cross-section view of a
microcondenser device according to another alternate
embodiment.
[0015] FIG. 8 is a plan cross-section view of the microcondenser
device of FIG. 7.
[0016] FIG. 9 is an elevational cross-section view of a
microcondenser device according to yet another alternate
embodiment.
[0017] FIG. 10 is a plan cross-section view of the microcondenser
device of FIG. 9.
[0018] FIG. 11 is a schematic elevational view of a microcondenser
device having a heat pipe (shown in cross-section) for removing
heat therefrom.
[0019] FIG. 12 is a schematic elevational view of a microcondenser
device having a cooling fluid circuit for removing heat
therefrom.
DETAILED DESCRIPTION
[0020] Referring now to the drawings wherein the showings are for
purposes of illustrating one or more exemplary embodiments and not
for purposes of limiting same, FIG. 1 schematically shows an
evaporative emission control system 10 for an internal combustion
engine 12. As shown, the engine 12 is provided with an induction
system including an intake pipe 14 in which a throttle valve 16 is
operatively mounted. A throttle valve opening (THA) sensor 18 is
connected to the throttle valve 16. The throttle valve opening
sensor 18 outputs a signal corresponding to the opening angle (THA)
of the throttle valve 16 and supplies the signal to an electronic
control unit (ECU) 20. Fuel injection valve 22, only one of which
is shown, are inserted into the intake pipe 14 at locations
intermediate between the cylinder block of the engine 12 and the
throttle valve 16 and slightly upstream of the respective intake
valves (not shown). The fuel injection valves 22 can be connected
through a fuel supply pipe 24 to a fuel tank 26 and a fuel pump
unit 28 is provided therealong for delivering fuel from the tank 26
to the fuel injection valves 22. Each fuel injection valve 22 can
be electrically connected to the ECU 20, and its valve opening can
be controlled by a signal from the ECU 20.
[0021] One or more sensors can be provided on the intake pipe 14
for monitoring conditions at the intake pipe. For example, the
intake pipe 14 can be provided with an intake pipe absolute
pressure (PBA) sensor 34 for detecting an absolute pressure (PBA)
in the intake pipe 14 and an intake air temperature (TA) sensor 36
for detecting an air temperature (TA) in the intake pipe 14 at
positions downstream of the throttle valve 16. These sensors,
including sensors 34, 36, can each output a signal corresponding to
a sensed condition (e.g., PBA or TA) and supply the outputted
signal to the ECU 20. In addition, the fuel tank 26 can be provided
with one or more sensors for monitoring specific conditions
associated therewith, including, for example, a tank pressure
(PTANK) sensor 38 for detecting a pressure (PTANK) in the fuel
tank, a fuel temperature (TGAS) sensor 40 for detecting a fuel
temperature (TGAS) in the fuel tank 26, and a fuel level sensor 42
for detecting a fuel level (i.e., a remaining fuel amount) in the
fuel tank 26. Like the other sensors described herein, the fuel
tank sensors, including sensors 38, 40, 42, can each output a
signal corresponding to a sensed condition at the fuel tank 26 and
provide the signal to the ECU 20.
[0022] Additional sensors can be provided on or in association with
the engine 12. More particularly, an engine rotational (NE) sensor
44 for detecting an engine rotational speed (NE) can be disposed
near the outer periphery of a camshaft or crankshaft (both not
shown) of the engine 12. There can also be provided an engine
coolant temperature sensor 46 for detecting a coolant temperature
(TW) of the engine 12 and an oxygen concentration sensor (also
referred to as a "LAF sensor") 48 for detecting an oxygen
concentration in exhaust gases from the engine 12. Detection
signals from these sensors 44, 46, 48 can be supplied to the ECU
20. The LAF sensor 48 can function as a wide-area air-fuel ratio
sensor adapted to output a signal substantially proportional to an
oxygen concentration and exhaust gases (i.e., proportional to an
air-fuel ratio of air-fuel mixture supplied to the engine 12).
[0023] The evaporative emission control system 10 further includes
a microcondenser device 50. With additional reference to FIG. 2,
the microcondenser device 50 includes a housing 52 having an inlet
54 for receiving fuel vapor and a condensation outlet 56 for
discharging condensed fuel vapor. In the illustrated embodiment,
the inlet 54 is connected to the fuel tank 26 through vapor line 58
so that fuel vapors formed in the fuel tank 26 can be delivered to
the microcondenser device 50. The condensation outlet 56 is also
connected to the fuel tank 26. In particular, the condensation
outlet 56 is connected to the fuel tank 26 through condensation
discharge line 60 for directing condensed vapor (i.e., liquid fuel)
from the microcondenser device back to the fuel tank 26. The
housing 52 can also have a vapor outlet 62 for discharging fuel
vapor that remains vaporized after passing through the
microcondenser device 50. In the illustrated embodiment, the vapor
outlet 62 is fluidly connected to the intake pipe 14 upstream of
the fuel injectors 22 via vapor line 64. This allows fuel vapor
discharged by the microcondenser device 50 to be recirculated
through the internal combustion engine 12 for combustion
therein.
[0024] As will be described in more detail below, the
microcondenser device 50 can also include a thermoelectric element
66 for condensing fuel vapors admitted through the inlet 54. The
thermoelectric element 66 can be a Peltier microelement that
employs or uses the Peltier effect to condense evaporative or
vaporized fuel received from the fuel tank 26 via the vapor line
58. Advantageously, providing the thermoelectric element 66 as a
Peltier microelement can be effective for condensing vaporized fuel
from the fuel tank 26 while being of a small size and requiring
minimum power consumption thereby not taxing the spatial layout of
the vehicle or its electrical system. Operation of the
microcondenser device 50 can occur as described in U.S. Pat. No.
7,527,045, which is expressly incorporated in its entirety
herein.
[0025] With additional reference to FIGS. 3 and 4, the housing 52
has a bottom or lower wall 70 and at least one side wall 72, 74,
76, 78 extending upward from the lower wall 70. The lower wall 70
and the at least one side wall 72-78 together define a chamber 80
in the housing 52. In the embodiment illustrated in FIGS. 2-4, the
housing 52 has a cuboid or box-shaped configuration such that the
at least one side wall includes four rectangular side walls 72, 74,
76, 78, each extending orthogonally upward from the lower wall 70.
As shown, the inlet 54 is defined in the housing 52, and
particularly the side wall 76 thereof, for admitting fuel vapor
into the chamber 80. The condensation outlet 56 is defined in the
housing 52, and particularly in the side wall 72 thereof, for
discharging liquid fuel that is condensed from the fuel vapor in
the chamber 80. The vapor outlet 62 is defined in the housing 52,
and particularly in the side wall 78 thereof, for discharging
uncondensed fuel vapor from the chamber 80.
[0026] The thermoelectric element 66 is supported by the at least
one side wall (i.e., side walls 72-78 in the embodiment illustrated
in FIGS. 2-4) in spaced relation relative to the lower wall 70. By
this arrangement, the thermoelectric element 66 is spaced apart
vertically from the bottom wall 70. For supporting the
thermoelectric element 66 in spaced relation relative to the lower
wall 70, the at least one side wall (i.e., side walls 72-78) can
include a recess 82 defined by a shoulder 84 and face 86 extending
upward from the shoulder 84. In particular, each of the side walls
72-78 of the illustrated embodiment can include shoulder 84 and
face 86 defining the recess 82. As shown, the thermoelectric
element 66 can be supported on the shoulder 84 and sized such that
at least one peripheral edge of the thermoelectric element 66 is
positioned closely adjacent the face 86. In the illustrated
embodiment, the thermoelectric element 66 can have a rectangular
configuration including four peripheral edges 66a and each
peripheral edge 66a can be positioned closely adjacent face 86 of a
corresponding one of the side walls 72-78. By this arrangement, the
thermoelectric element 66 is nestably received within the recess 82
defined in the housing 52.
[0027] A porous heat sink element 100 can be disposed in the
housing 52, and particularly received in the chamber 80 of the
housing 52. The porous heat sink element is fluidly interposed
between the inlet 54 and the condensation outlet 56 for absorbing
the fuel vapor received or admitted through the inlet 54. The
thermoelectric element 66 can be in thermal contact with the porous
heat sink element 100 for removing heat from the fuel vapor
absorbed by the porous heat sink element 100 to condense the fuel
vapor. In particular, the porous heat sink element 100 can be in
conductive thermal contact with the thermoelectric element 66. In
addition to be interposed between the inlet 54 and the condensation
outlet 56, the porous heat sink element 100 is also fluidly
interposed between the inlet 54 and the vapor outlet 62, which
discharges fuel vapor that remains vaporized after passing through
the porous heat sink 100.
[0028] In one embodiment, the porous heat sink element 100 is a
carbon foam heat sink element. Being formed of carbon foam provides
advantages such as higher thermal conductivity and greater surface
area per unit volume than conventional heat sinks and/or heat sinks
formed of aluminum fins. Moreover, the carbon foam heat sink
element 100 has greater heat transfer efficiency than conventional
arrangements which results in the overall electric load needed to
power the microcondenser device 50 being considerably lower than
would be necessary if the heat sink were formed with conventional
fins.
[0029] In the illustrated embodiment, a copper plate 102 is
interposed between the porous heat sink element 100 and the
thermoelectric element 66. Accordingly, conductive heat transfer
occurs from the porous heat sink element 100, then to the copper
plate 102, and next to the thermoelectric element 66. Using the
copper plate 102 allows for improved heat transfer from the porous
heat sink element 100 to the thermoelectric element 66. In
particular, the copper plate 102 can have an improved flatness,
particularly on a side 104 that interfaces with the porous heat
sink element 100 (i.e., improved flatness compared to other
efficient heat transfer materials). In addition, a thermal paste
106 can be interposed between at least one of the copper plate 102
and the thermoelectric element 66 or the copper plate 102 and the
porous heat sink element 100. In the illustrated embodiment, as
shown, thermal paste 106 is interposed between both the copper
plates 102 and the thermoelectric element 66 and the copper plate
102 and the porous heat sink element 100. The thermal paste 106
facilitates better heat transfer between conductive elements of the
microcondenser device 50.
[0030] As shown in the illustrated embodiment, the copper plate 102
is supported by the shoulder 84 and the thermoelectric element 66
is supported on top of the copper plate 102. Together, the
thermoelectric element 66 and the copper plate 102 are nestably
received within the recess 82 defined in the housing 52.
Particularly, in the illustrated embodiment, these elements 66, 102
form an upper side of the housing 52 and close the chamber 80
defined by the housing 52. A seal 108 can be interposed between the
underside 104 of the copper plate 102 and the shoulder 84 defined
in each of the side walls 72-78. The nesting relation of the copper
plate 102 and the thermoelectric element 66 within the recess 82
and/or the provision of the seal 108 is believed to advantageously
reduce or eliminate frost or fog formation on the microcondenser
device 50, and particularly the housing 52 thereof, which improves
efficiency of the device 50 (i.e., less power is needed to operate
the device). [Question for inventors: what material is the seal 108
formed of?]
[0031] Also to improve efficiency of the microcondenser device 50,
the housing 52 can be formed of a plastic material. This provides
the housing 52 with a low heat mass body and a low thermal
conductivity body material. The particular plastic material
employed for the housing 52 can have sufficient rigidity while
otherwise reducing the amount of energy needed for the
thermoelectric element 66 to cool vaporized fuel passing through
the porous heat sink element 100. Using plastic also provides an
additional minimal weight benefit through the use of a lighter
material.
[0032] Specifically, for example, the body material of the housing
52 can be polyamide, polyacetal, PEI, PPS, or any other
fuel-resistant plastic material providing for low heat loss and/or
low thermal mass. In addition, to further limit thermal loss to the
environment, an insulation or an insulating layer can be disposed
one of: around an exterior of the housing 52 or inside the housing
around the porous heat sink element 100. In the illustrated
embodiment, a foam insulating layer 110 is shown provided around an
exterior of the housing 52. Alternatively, other insulating
materials can be applied to the exterior of the housing 52. For
example, aerogels or other foams can be applied to an exterior of
the housing for insulating the housing from thermal losses to the
surrounding environment.
[0033] The microcondenser device 50 can additionally include at
least one support baffle supporting the porous heat sink element
100 within the housing 52. As will be described in more detail
below, the at least one support baffle supports the porous heat
sink element 100 in an elevated position (i.e., in spaced apart
relation) from the lower wall 70 and in conductive thermal contact
with the thermoelectric element 66. As will also be described in
more detail below, the at least one support baffle can urge the
porous heat sink element 100 toward the thermoelectric element 66
and/or into thermal contact with the thermoelectric element 66. The
at least one support baffle can be one or more baffles shaped or
configured to provide various sub-chambers within the chamber 80 of
the housing 52. The baffles can be formed of a foam insulation
material, such as a Teflon foam insulation, for example, which
provides the baffles with some resiliency and enable the stacked
baffles to urge the porous heat sink element 100 toward the copper
plate 102, which assists in efficient heat transfer
therebetween.
[0034] In the illustrated embodiment, the at least one support
baffle includes a plurality of stacked baffles, which facilitates
the baffles urging or supplying support pressure against the porous
heat sink element 100. Whether stacked, shaped or otherwise
configured, the one or more support baffles can be arranged to
efficiently direct fuel vapor into the porous heat sink element 100
and/or to facilitate efficient liquid drainage (i.e., condensed
fuel vapor). In the illustrated embodiment, the plurality of
baffles includes a base baffle 112 having a cut out or recess 114
accommodating the condensation outlet 56. Intermediate baffles 116,
118, 120, 122 are stacked on the base baffle 112. In particular,
intermediate baffles 116, 118 are together stacked and form a first
pair of stacked baffles. Likewise, intermediate baffles 120, 122
are together stacked and form a second pair of stacked baffles.
Thus, the baffles 116-122 are arranged in stacked pairs wherein the
first pair of stacked baffles 116, 118 are together stacked
adjacent the inlet 54 and the second pair of baffles 120, 122 are
stacked adjacent the vapor outlet 62, and wherein the pairs of
stacked baffles 116, 118 and 120, 122 flank the condensation outlet
56.
[0035] The baffles can be arranged so as to direct gas and/or
liquid flow within the microcondenser device 50 and support the
porous heat sink element 100. For example, upper baffles 124, 126
are disposed in stacked relation above the intermediate baffles
116-122 and can directly support the porous heat sink element 100.
In particular, the illustrated embodiment, the upper baffle 124 is
stacked on the first pair of intermediate baffles 116, 118 adjacent
the vapor inlet 54 and the upper baffle 126 is stacked on the
second pair of intermediate baffles 120, 122 adjacent the vapor
outlet 62. Like the intermediate baffles 116-122, the upper baffles
124, 126 can be laterally spaced apart from one another to flank
the condensation outlet 56.
[0036] In the illustrated embodiment of FIGS. 2-4, the baffles are
arranged so as to define a plenum chamber 128 adjacent the vapor
inlet 54 and extending from the side wall 72 to the side wall 74.
The plenum chamber 128 can allow the fuel vapor admitted through
the vapor inlet 54 to expand along a dimension of the porous heat
sink element 100 extending from the side wall 72 to the side wall
74 and thus more effectively absorb the fuel vapor. In particular,
the plenum chamber 128 of the illustrated embodiment is formed by
the side walls 72, 74, 76, the baffles 118 and 124, and the porous
heat sink element 100. The plenum chamber 128 extends along
substantially an entire width of the porous heat sink element 100
(e.g., the width extending between the side walls 72, 74). The
plenum chamber 128 can function to ensure that fuel vapor entering
through the inlet 54 is allowed to spread out before being absorbed
into the porous heat sink element 100.
[0037] The baffles also define a condensation chamber 130
vertically between the condensation outlet 56 and the porous heat
sink element 100. As shown, the condensation chamber 130 is
disposed below the porous heat sink element 100. This allows
gravity to assist in removing condensed fuel from the porous heat
sink element 100 and directing the same to the condensation outlet
56. The upper baffle 124 is smaller in the illustrated embodiment
that the upper baffle 126, which defines an expanded area 132 of
the condensation chamber 130. The expanded area 132 facilitates
gravitational removal of condensed fuel from the porous heat sink
element 100 on a side of the condensation chamber 130 adjacent the
vapor inlet 54. [is this correct?]
[0038] With reference to FIGS. 5 and 6, a microcondenser device 150
is illustrated. The microcondenser device 150 can be the same as
the microcondenser device 50 except as indicated below. In FIGS. 5
and 6, the base and intermediate stacked baffles of the
microcondenser device 50 are replaced with a single shaped baffle
152 that includes a base portion 154 similar in configuration to
the base baffle 112 and intermediate baffle portions 156, 158 that
are similar in configuration to the stacked intermediate baffles
116-122. The microcondenser device 150 includes upper baffles 160,
162 disposed in stacked relation on the intermediate baffle
portions 156, 158. Unlike the microcondenser device 50, the
microcondenser 150 has its upper baffles 160, 162 sized and
arranged to provide varying shapes for plenum chamber 164 and
condensation chamber 166. In particular, the upper baffle 160 has a
rear side 168 aligned with a rear side 170 of the intermediate
baffle portion 156. Accordingly, no expanded area 132 is defined
above the intermediate baffle portion 156; however, the plenum
chamber 164 has an increased depth (i.e., a dimension from the
vapor inlet 54 and/or side wall 76 to the upper baffle 160).
Instead of the expanded area 132, an expanded area 172 is disposed
above the intermediate baffle portion 158. The expanded area 172
results from the rear edge 174 of the upper baffle 162 being
laterally spaced apart from the rear side 176 of the intermediate
baffle portion 158.
[0039] With reference to FIGS. 7 and 8, another microcondenser
device 250 is illustrated. The microcondenser device 250 can be the
same as the microcondenser device 150 except as indicated below. In
the embodiment illustrated in FIGS. 7 and 8, the upper baffle 162
is replaced with upper baffle 126 (i.e. the same baffle used in the
microcondenser device 50). Accordingly, in this embodiment, there
is no expanded area of the condensation chamber 130 above the
intermediate baffle portion 156 or above the intermediate baffle
portion 158, only the enlarged plenum chamber 164.
[0040] With reference to FIGS. 9 and 10, still another
microcondenser device 350 is illustrated, which can be the same as
the microcondenser device 150 except as indicated below. In the
microcondenser device 350, upper baffle 124 (same as used in the
microcondenser 50) is disposed above the intermediate baffle
portion 156 and the upper baffle portion 162 is disposed above the
intermediate baffle portion 158. Accordingly, by this arrangement,
expanded area 132 is disposed above the intermediate baffle portion
156 and expanded area 172 is disposed above the intermediate baffle
portion 158. A small plenum chamber 128 is also disposed above the
intermediate baffle portion 156 adjacent the inlet 54.
[0041] Returning reference to FIGS. 2-4, the porous heat sink
element 100 can have a varying porosity. One exemplary varying
porosity for the porous heat sink element 100 is schematically
illustrated by the stippling in the figures. As shown, the porous
heat sink element 100 can have an increased porosity at a first
side or portion 100a, which is adjacent the plenum chamber 128 and
the inlet 54, than adjacent a second side or portion 100b. The
porous heat sink element 100 can also have an increased porosity
adjacent an underside or underside portion 100c than an upper side
or upper side portion 100d that is adjacent the thermoelectric
element 66. While the illustrated embodiment includes progressively
decreasing porosity from the first side portion 100a to the second
side portion 100b and from the underside portion 100c to the upper
side portion 100d, it is to be appreciated that such varying
porosity could occur only from one side to another (e.g., from side
portion 100a to side portion 100b or from side portion 100c to side
portion 100d). Alternatively, other arrangements or patterns of
varying porosity could be used with the heat sink element 100.
[0042] As best shown in FIG. 3, the arrangement of the vapor inlet
54 and the outlets 56, 62 relative to one another can facilitate
efficient vapor flow and liquid flow through the microcondenser
device 50. As used herein, relative positioning can refer to
positioning of a central axis or central area of each of the inlet
54 and outlets 56, 62 relative to one another. In particular, as
shown, the vapor outlet 62 can be relatively positioned vertically
above the vapor inlet 54 and above the condensation outlet 56. The
condensation outlet 56 can be relatively positioned below the vapor
inlet 54 and below the vapor outlet 62. The vapor inlet 54 can be
disposed vertically between the vapor outlet 62 and the
condensation outlet 56. In addition to relative positioning,
relative sizing can facilitate efficient fuel flow through the
microcondenser device 50. For example, as shown, the vapor inlet 54
can have an increased size relative to the condensation outlet 56,
which itself can have an increased size relative to the vapor
outlet 62.
[0043] With reference to FIGS. 11 and 12, the microcondenser device
50 can additionally include a heat removal assembly 170 or 172 that
is in thermal contact with a hot side 66b of the thermoelectric
element 66. The heat removal assembly 170 or 172 can comprise at
least one of heat pipe 170 (FIG. 11) or a liquid cooling circuit
172 (FIG. 12). In FIG. 11, an exemplary heat pipe 170 is shown
having a casing 174, a wick 176 and a vapor cavity 178. As is known
and understood by those skilled in the art, the heat pipe 170 can
facilitate more rapid removal of heat from the hot side 66b of the
thermoelectric element 66, which reduces the power consumption of
the thermoelectric element for condensing fuel vapor in the cavity
80. In FIG. 12, an exemplary liquid cooling circuit 172 is shown
having a pump 180, a heat exchanger 182 and a liquid circulation
loop 184. As is known and understood by those skilled in the art,
the pump 180 circulates a heat transfer fluid (e.g., antifreeze) in
the loop 184 from the hot side 66b of the thermoelectric element 66
where the fluid absorbs heat from the thermoelectric element 66 to
the heat exchanger 182 where the fluid dissipates its absorbed
heat. Alternatively or in addition, the hot side 66a of the
thermoelectric element 66 can be cooled by convection fins and/or a
fan (both not shown). Although not shown, a thermal paste can be
used between the heat removal assembly 170 or 172 and the hot side
66a of the thermoelectric element 66. Using the heat pipe 170 or
the liquid cooling circuit 172, rapid heat removal can occur from
the hot side 66a of the thermoelectric element 66 increasing its
efficiency.
[0044] Advantageously, the microcondenser devices described herein
can provide improved efficiencies which allow the devices to have
smaller footprints when employed in a vehicle electrical system. It
will be appreciated that various of the above-disclosed and other
features and functions, or alternatives or varieties thereof, may
be desirably combined into many other different systems or
applications. Also that various presently unforeseen or
unanticipated alternatives, modifications, variations or
improvements therein may be subsequently made by those skilled in
the art which are also intended to be encompassed by the following
claims.
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