Information
-
Patent Grant
-
6230787
-
Patent Number
6,230,787
-
Date Filed
Tuesday, November 9, 199924 years ago
-
Date Issued
Tuesday, May 15, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 165 41
- 165 153
- 165 144
- 165 176
- 062 515
-
International Classifications
-
Abstract
A stack type evaporator for use in an automotive air conditioner comprises generally a first mass which includes first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; and a second mass which includes second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends. The second mass is arranged beside the first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis. An inlet tank passage connects to upper ends of the first passages. An upstream tank passage connects to lower ends of the first passages and the first ends of the third passages. A downstream tank passage connects to lower ends of the second passages and the second ends of the third passages. An outlet tank passage connects to upper ends of the second passages. An inlet pipe connects to the inlet tank passage. An outlet pipe is connected to the outlet tank passage.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to heat exchangers for use in automotive air conditioners, and more particularly to evaporators of a stack type.
2. Description of the Prior Art
In order to clarify the tasks of the present invention, two conventional stack type evaporators
1
and
1
′ for automotive air conditioners will be described with reference to
FIGS. 24
to
26
and
FIGS. 27
to
30
.
One of them is shown in
FIGS. 24
to
26
, which is described in for example Japanese Patent First Provisional Publication 62-798 and Japanese Patent 2,737,286.
As is seen from
FIGS. 24 and 25
, the first conventional evaporator
1
comprises a core unit
5
. Refrigerant inlet and outlet pipes
3
and
4
are fluidly connected to the core unit
5
, which are held by a coupler
2
. Under operation, a liquid-gaseous refrigerant is led into the core unit
5
through the inlet pipe
3
and evaporates to cool the core unit
5
. With this, air flowing through the core unit
5
is cooled. Gaseous refrigerant produced as a result of the evaporation is led into the outlet pipe
4
and into a compressor (not shown). The evaporator
1
is of a so-called “stack type” which comprises a plurality of elongate flat tubes or heat exchanging elements which are stacked, each including two mutually coupled elongate shell plates. Japanese Patent 2737286 shows an alternate arrangement of two areas for the refrigerant, one being a lower temperature area mainly occupied by a liquid refrigerant and the other being a higher temperature area mainly occupied by a gaseous refrigerant. With this alternate arrangement, the evaporator can exhibit a desired temperature distribution thereon.
As is seen from
FIG. 25
, in assembly of the air conditioner, the evaporator
1
and a heater core
9
are arranged perpendicular to a dash panel
8
by which an engine room
6
and a passenger room
7
are partitioned, and air for conditioning the passenger room is forced to flow in the direction of the arrow “a”, that is, in a direction parallel with the dash panel
8
. Although not shown in the drawing, a duct is provided in the passenger room
7
to assure such air flow. That is, the evaporator
1
and the heater core
9
are installed in the duct. The coupler
2
is exposed to the engine room
6
through an opening
10
formed in the dash panel
8
, so that the evaporator
1
is fluidly connected through pipes to a compressor (not shown) and a condenser (not shown) which are arranged in the engine room
6
.
Nowadays, for improving air flow in the passenger room
7
, there has been proposed an arrangement wherein, as is seen from
FIG. 26
, the evaporator
1
and the heater core
9
are arranged in parallel with the dash panel
8
, and the air for conditioning the room
7
is forced to flow in the direction of the arrow “b”. However, in this case, it becomes necessary to use much longer and complicated pipes as the inlet and outlet pipes
3
and
4
as is easily understood from the drawing. Of course, such arrangement brings about increase in cost of the air conditioner. Furthermore, due to usage of such complicated and longer pipes
3
and
4
, the flow resistance of the refrigerant becomes marked and thus the air conditioner fails to exhibit a satisfied performance.
The other conventional stack type evaporator
1
′ is shown in
FIGS. 27
to
30
, which is described in for example Japanese Patent First Provisional Publication 62-798 and Japanese Utility Model First Provisional Publication 7-12778.
As is seen from the drawings, the second conventional evaporator
1
′ comprises a core unit
3
′. The core unit
3
′ comprises a plurality of elongate flat tubes
10
′ (or heat exchanging elements) which are stacked, each including two mutually coupled elongate shell plates. Each elongate flat tube
10
′ has two mutually independent flow passages
2
′ and
2
′ defined therein. A plurality of heat radiation fins
11
′ are alternatively disposed in the stacked elongate flat tubes
10
′. The two passages
2
′ and
2
′ defined in each flat tube
10
′ have upper and lower tank spaces. By connecting or communicating adjacent flat tubes
10
′ at the respective upper and lower tank spaces, there are formed a plurality of tank portions
4
′,
5
′ and
6
′. As is seen from
FIGS. 28
to
30
, at one end of the core unit
3
′, there is provided a side tank portion
7
′ by which the two tank portions
4
′ and
4
′ are connected. Under operation, a liquid-gaseous refrigerant is led through an inlet pipe
8
′ and the inlet tank portion
5
′ (see
FIG. 28
) into the core unit
3
′. The refrigerant flows in the passages
2
′ and
2
′ of the core unit
3
′ while evaporating to cool the core unit
3
′. During this, the refrigerant flows also in the side tank portion
7
′. Thus, air flowing through the core unit
3
′ in the direction of the arrow “α” (see
FIGS. 28
to
30
) is cooled. Gaseous refrigerant produced as a result of the evaporation is led to an outlet pipe
9
′ and to a compressor (not shown).
However, the above-mentioned other conventional stack type evaporator
1
′ has the following drawbacks due to its inherent construction.
First, actually, the side tank portion
7
′ does not contribute anything to the air cooling because the portion
7
′ is positioned away from the air passing path. This brings about unsatisfied performance of the air conditioner.
Second, as is seen from
FIG. 29
, under operation of the evaporator
1
′, due to the nature of the gravity, the liquid-gaseous refrigerant flowing in the upper tank portions
5
′ and
4
′ of the core unit
3
′ is forced to feed a larger amount of refrigerant to upstream positioned flow passages
2
′ and
2
′ and a smaller amount of refrigerant to downstream positioned flow passages
2
′ and
2
′. The amount of the refrigerant in each area of the flow passages
2
′ and
2
′ is indicated by the down-pointed arrows in the drawing. While, due to inertia of the refrigerant, the refrigerant flowing in the lower tank portions
4
′ and
4
′ of the core unit
3
′ is forced to feed a smaller amount of refrigerant to upstream positioned flow passages
2
′ and
2
′ and a larger amount of refrigerant to downstream positioned flow passages
2
′ and
2
′. The amount of the refrigerant in each area of the flow passages
2
′ and
2
′ is indicated by the up-pointed arrows in the drawing. That is, the refrigerant flow rate in the core unit
3
′ is smaller in the inside portion than the outside portion. Thus, as is seen from
FIG. 31
, the core unit
3
′ fails to have a uniformed temperature distribution therethroughout. That is, in the drawing, the outside portions of the core unit
3
′ indicated by grids are forced to show a low temperature as compared with the inside portions thereof. This means that the air passing through the core unit
3
′ fails to have a uniformed temperature distribution, which tends to make passengers in the passenger room uncomfortable.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a stack type evaporator which is free of the above-mentioned drawbacks.
According to a first aspect of the present invention, there is provided a stack type evaporator which comprises a first mass including first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; a second mass including second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends, the second mass being arranged just beside the first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis; an inlet tank passage connecting to upper ends of the first passages; an upstream tank passage connecting to lower ends of the first passages and the first ends of the third passages; a downstream tank passage connecting to lower ends of the second passages and the second ends of the third passages; an outlet tank passage connecting to upper ends of the second passages; an inlet pipe connected to the inlet tank passage; and an outlet pipe connected to the outlet tank passage.
According to a second aspect of the present invention, there is provided an arrangement in a motor vehicle having an engine room and a passenger room which are partitioned by a dash panel. The arrangement comprises an evaporator which includes a first mass including first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; a second mass including second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends, the second mass being arranged just beside the first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis; an inlet tank passage connecting to upper ends of the first passages; an upstream tank passage connecting to lower ends of the first passages and the first ends of the third passages; a downstream tank passage connecting to lower ends of the second passages and the second ends of the third passages; an outlet tank passage connecting to upper ends of the second passages; an inlet pipe connected to the inlet tank passage; and an outlet pipe connected to the outlet tank passage; means for placing the evaporator in such a manner that the evaporator is arranged in parallel with the dash panel and that the inlet tank passage and the upstream tank passage are positioned away from the dash panel as compared with the outlet tank passage and the downstream tank passage; and means for producing an air flow through the evaporator in a direction from the dash panel toward the evaporator.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, in which:
FIG. 1
is front view of a stack type evaporator according to the present invention;
FIG. 2
is a side view of the evaporator of the invention;
FIG. 3
is a plan view of the evaporator of the invention;
FIG. 4A
is a schematic sectional view of one heat exchanging element employed in the evaporator of the invention, which is taken from the direction “IV” of
FIG. 1
;
FIG. 4B
is a view similar to
FIG. 4A
, but showing another exchanging element employed in the evaporator of the invention;
FIG. 5A
is a sectional view of the heat exchanging element of
FIG. 4A
, which is taken from the direction “VA” of
FIG. 5B
;
FIG. 5B
is a sectional view of the heat exchanging element of
FIG. 4A
, which is taken from the direction “VB” of
FIG. 5A
;
FIG. 6A
is a sectional view of the heat exchanging element of
FIG. 4B
, which is taken from the direction “VIA” of
FIG. 6B
;
FIG. 6B
is a sectional view of the heat exchanging element of
FIG. 4B
, which is taken from the direction “VIB” of
FIG. 6A
;
FIG. 7
is a schematically illustrated perspective view of the evaporator of the invention, showing the path of refrigerant;
FIGS. 8A and 8B
are perspective view of two connector constructions employable in the invention;
FIGS. 9A
,
9
B and
9
C are perspective views of upper portions of three recessed metal plates each being an essential part of a heat exchanging element, the upper portions having connector structures;
FIG. 10
is a schematically illustrated perspective view of the evaporator of the invention, showing the path of refrigerant in the evaporator;
FIG. 11
is a schematic plan view of a part of a motor vehicle where the evaporator of the invention associated with an air conditioner is operatively arranged;
FIG. 12
is a schematic perspective view of the evaporator of the invention, showing the flow condition of refrigerant in the evaporator;
FIG. 13
is a schematic view of the evaporator of the invention, showing a temperature distribution possessed by the evaporator;
FIG. 14
is a view similar to
FIG. 10
, but showing a first modification of the evaporator of the present invention;
FIG. 15
is a schematic plan view of a part of a motor vehicle where the first modification of the evaporator associated with an air conditioner is operatively arranged;
FIG. 16
is a schematic view of a second modification of the evaporator of the present invention, showing the path of refrigerant in the evaporator;
FIG. 17
is a schematic perspective view of the second modification of the evaporator of the invention;
FIG. 18
is an exploded perspective view of one heat exchanging element and its associated connector structure, which are employed in the second modification of the evaporator of
FIG. 17
;
FIG. 19
is a sectional view of an assembled unit including the heat exchanging element and the associated connector structure of
FIG. 18
;
FIG. 20
is a view similar to
FIG. 14
, but showing the flow condition of refrigerant in the second modification of the evaporator of the invention;
FIG. 21
is a view similar to
FIG. 15
, but showing a temperature distribution possessed by the second modification of the evaporator of the invention;
FIG. 22
is a view similar to
FIG. 18
, but showing a third modification of the evaporator of the invention;
FIG. 23
is a view similar to
FIG. 16
, but showing a fourth modification of the evaporator of the present invention;
FIG. 24
is a perspective view of a first conventional evaporator;
FIG. 25
is a plan view of a part of a motor vehicle where the first conventional evaporator associated with an air conditioner is operatively arranged;
FIG. 26
is a view similar to
FIG. 25
, but showing a drawback which is possessed by the first conventional evaporator when the same is arranged in a different way;
FIG. 27
is a perspective view of a second conventional evaporator;
FIG. 28
is a schematic perspective view of the second conventional evaporator, showing the path of refrigerant in the evaporator;
FIG. 29
is a schematic perspective view of the second conventional evaporator, showing flow condition of refrigerant in the evaporator;
FIG. 30
is a schematic view of the second conventional evaporator, showing a temperature distribution possessed by the evaporator.
DETAILED DESCRIPTION OF THE INVENTION
In the following, the present invention will be described in detail with reference to the accompanying drawings. For ease of understanding, directional terms, such as, right, left, upper, lower and the like are used. However, these directional terms are to be understood with respect to the drawings in which the objective structures or parts are illustrated.
Referring to
FIGS. 1
to
13
of the drawings, particularly
FIGS. 1
,
2
,
3
,
7
and
10
, there is shown a stack type evaporator
100
according to the present invention.
As is seen from
FIGS. 1
,
2
and
3
, the evaporator
100
has a rectangular core unit
105
which comprises a first group of heat exchanging elements
111
, a second group of heat exchanging elements
112
, and a plurality of hear radiation fins
113
interposed between every adjacent two of the heat exchanging elements
111
and
112
. For ease of description, each of the first group of heat exchanging elements
111
will be referred to first heat exchanging element
111
, and each of the second group of heat exchanging elements
112
will be referred to second heat exchanging element
112
, hereinafter.
As is seen from
FIGS. 1
,
2
and
3
, at an upper middle portion of the core unit
105
, there are provided an inlet pipe connector
114
and an outlet pipe connector
115
. As is understood from
FIG. 2
, upon arrangement of the evaporator
100
in an associated automotive air conditioner, the evaporator
100
is so oriented as having the pipe connectors
114
and
115
directed against an air flow. The inlet pipe connector
114
is connected to an inlet pipe
103
through which a liquid-gaseous refrigerant is led into the core unit
105
, and the outlet pipe connector
115
is connected to an outlet pipe
104
through which a gaseous refrigerant is discharged from the core unit
105
.
As is seen from
FIG. 8A
, the inlet pipe connector
114
(or outlet pipe connector
115
) has a circular opening with which an end of the inlet pipe
103
(or outlet pipe
104
) is engaged and brazed. However, if desired, as is seen from
FIG. 8B
, the pipe
103
or
104
may have a connector
114
or
115
integrally connected thereto. In this case, a sealing piece
116
is used for shutting the open end of the integrated connector
114
or
115
.
Furthermore, as is seen from
FIGS. 9B and 9C
, the connector
114
or
115
may be integrated with a recessed metal plate
117
which is a part of an associated heat exchanging element
111
or
112
.
That is, as is shown in
FIGS. 5A and 5B
, each of the first group of heat exchanging elements
111
comprises two identical recessed metal plates
117
, only one being shown in the drawings. As is shown in
FIGS. 6A and 6B
, each of the second group of heat exchanging elements
112
comprises two identical recessed metal plates
118
, only one being shown in the drawings.
The two identical metal plates
117
and
117
(or,
118
and
118
) are coupled in a so-called face-to-face connecting manner to define therebetween a hermetically sealed flat flow passage. More specifically, as is understood from
FIGS. 4A and 5B
, the first heat exchanging element
111
is constructed to have therein two parallel straight flow passages
120
and
121
, while, as is understood from
FIGS. 4B and 6B
, the second heat exchanging element
112
is constructed to have therein a U-shaped flow passage
122
, for the reason which will become apparent as the description proceeds.
As will be described hereinafter, one of the first and second recessed metal plates
117
and
118
may have such a structure as shown in
FIG. 9A
,
9
B or
9
C. If the structures as shown in
FIGS. 9B
and
9
C are used, reduction in number of parts is achieved because of the integrated formation of the connector
114
or
115
.
Each of the recessed metal plates
117
and
118
is a clad metal which includes an aluminum alloy core plate of higher melting point having both surfaces laminated with brazing aluminum alloy plates of lower melting point. Usually, adding silicon (Si) to the aluminum alloy lowers the melting point of the alloy.
For producing the evaporator
100
, a plurality of coupled metal plates
117
and
117
for the first group of heat exchanging elements
111
, a plurality of coupled metal plates
118
and
118
for the second group of heat exchanging elements
112
, a plurality of heat radiation fins
113
, inlet and outlet pipe connectors
114
and
115
and a pair of side plates
119
are temporarily assembled in a holder (not shown) in such an arrangement as shown in
FIG. 1
, and then the temporarily assembled unit is put into a brazing furnace (not shown) for a certain time to braze the parts. With this, the parts
117
,
118
,
113
,
103
,
104
,
114
,
115
and
119
are brazed to one another to constitute a fixed unit of the evaporator
100
.
As has been mentioned hereinabove, a right half of the stack type evaporator
100
(see
FIG. 1
) comprises a plurality of the first heat exchanging elements
111
(viz., first group of heat exchanging elements
111
) and associated heat radiation fins
113
, and a left half of the evaporator
100
comprises a plurality of the second heat exchanging elements
112
(viz., second group of heat exchanging elements
112
) and associated heat radiation fins
113
.
As is shown in
FIG. 4A
, each first heat exchanging element
111
has therein two parallel straight flow passages
120
and
121
, and as is shown in
FIG. 4B
, each second heat exchanging element
112
has therein a U-shaped flow passage
122
.
As is seen in
FIG. 5B
, each metal plate
117
for the first heat exchanging element
111
has at an upper end two (viz., first and second) circular openings
123
and
124
, and at a lower end two (viz., third and fourth) circular openings
125
and
126
, each opening
123
,
124
,
125
or
126
being defined in a depressed part of the upper or lower end of the plate
117
. Furthermore, each metal plate
117
has two parallel shallow grooves
127
and
128
which extend between the openings
123
and
125
and between the openings
124
and
126
, respectively. It is to be noted that the shallow groove
127
constitutes the straight flow passage
120
of the first heat exchanging element
111
(see FIG.
4
A), and the other shallow groove
128
constitutes the other straight flow passage
121
of the first heat exchanging element
111
.
As has been mentioned hereinabove, the two metal plates
117
and
117
are coupled in a face-to-face contacting manner to constitute the first heat exchanging element
111
. With this coupling, as is seen from
FIG. 4A
, the element
111
becomes to have at its upper end two (viz., first and second) tank spaces
129
and
130
, and at its lower end two (third and fourth) tank spaces
131
and
132
, the first tank space
129
being defined between the opening
123
of the metal plate
117
and the corresponding opening (
124
) of the partner metal plate
117
, the second tank space
130
being defined between the opening
124
of the metal plate
117
and the corresponding opening (
123
) of the partner metal plate
117
, the third tank space
131
being defined between the opening
125
of the metal plate
117
and the corresponding opening (
126
) of the partner metal plate
117
and the fourth tank space
132
being defined between the opening
126
of the metal plate
117
and the corresponding opening (
125
) of the partner metal plate
117
.
Furthermore, with the coupling between the two metal plates
117
and
117
for constituting the first heat exchanging element
111
, there are defined in the element
111
(see
FIG. 4A
) the two parallel straight flow passages
120
and
121
. The passage
120
extends between the first tank space
129
and the third tank space
131
, and the other passage
121
extends between the second tank space
130
and the fourth tank space
132
.
As is seen from
FIG. 5B
, bottom surfaces of the two parallel shallow grooves
127
and
128
of each metal plate
117
are formed with a plurality of studs
133
. Upon coupling between the paired metal plates
117
and
117
, the studs
133
of one metal plate
117
abut against the studs
133
of the partner's metal plate
117
respectively. These abutting studs
133
become brazed when heated in the brazing furnace. Due to provision of such studs
133
, the coupling between the paired metal plates
117
and
117
is assured and the refrigerant flow in the two flow passages
120
and
121
is suitably diffused.
As is seen in
FIG. 6
, each metal plate
118
for the second heat exchanging element
112
has an upper end two (fifth and sixth) circular openings
134
and
135
, and at a lower end two (viz., seventh and eighth) circular openings
136
and
137
, each opening
134
,
135
,
136
or
137
being defined in a depressed part of the upper and lower end of the plate
118
. Furthermore, each metal plate
118
has a U-shaped shallow groove
138
which comprises two parallel shallow groove parts (no numerals) each having one end connected to the seventh or eighth circular opening
136
or
137
and a short shallow groove part (no numeral) connecting the other ends of the two parallel shallow groove parts. It is to be noted that U-shaped shallow groove
138
constitutes the U-shaped flow passage
121
of the second heat exchanging element
112
(see FIG.
4
B).
As has been mentioned hereinabove, the two metal plates
118
and
118
are coupled in a face-to-face contacting manner to constitute the second heat exchanging element
112
. With this coupling, as is seen from
FIG. 4B
, the element
112
becomes to have at its upper end two (viz., fifth and sixth) tank spaces
139
and
140
, and at its lower end two (viz., seventh and eighth) tank spaces
141
and
142
, the fifth tank space
139
being defined between the opening
134
of the metal plate
118
and the corresponding opening (
135
) of the partner metal plate
118
, the sixth tank space
140
being defined between the opening
135
of the metal plate
118
and the corresponding opening (
134
) of the partner metal plate
118
, the seventh tank space
141
being defined between the opening
136
of the metal plate
118
and the corresponding opening (
137
) of the partner metal plate
118
and the eighth tank space
142
being defined between the opening
137
of the metal plate
118
and the corresponding opening (
136
) of the partner metal plate
118
.
Furthermore, with the coupling between the two metal plates
118
and
118
for constituting the second heat exchanging element
112
, there are defined in the element
112
(see
FIG. 4B
) the U-shaped flow passage
122
. This passage
122
extends between the seventh and eighth tank spaces
141
and
142
. It is to be noted that the passage
122
is isolated from the fifth and sixth tank spaces
139
and
140
, as is seen from the drawing (FIG.
4
B).
As is seen from
FIG. 6B
, a bottom surface of the U-shaped shallow groove
138
of each metal plate
118
is formed with a plurality of studs
133
. Upon coupling between the paired metal plates
118
and
118
, the studs
133
of one metal plate
118
abut against the studs
133
of the partner's metal plate
118
respectively. The abutting studs
133
become brazed when heated in the brazing furnace. If desired, the fifth and sixth tank spaces
139
and
140
may be removed. However, in this case, it becomes necessary to provide between the upper ends of any adjacent two of the second heat exchanging elements
112
and
112
a distance keeping element.
As is seen from
FIGS. 3 and 7
, upon assembly of the evaporator
100
, the first tank spaces
129
of the first heat exchanging elements
111
are aligned and connected to one another to constitute an inlet tank portion
143
. The inlet tank portion
143
is connected through the inlet pipe connector
114
to the inlet pipe
103
. It is to be noted that the rightmost one of the first metal plates
117
as viewed in
FIGS. 1 and 3
has no opening corresponding to the opening
123
(see FIG.
5
B).
Furthermore, as is seen from
FIGS. 3 and 7
, upon assembly of the evaporator
100
, the second tank spaces
130
of the first heat exchanging elements
111
are aligned and connected to one another to constitute an outlet tank portion
145
. The outlet tank portion
145
is connected through the outlet pipe connector
115
to the outlet pipe
104
. It is to be noted that the rightmost one of the first metal plates
117
as viewed in
FIGS. 1 and 3
has no opening corresponding to the opening
124
(see FIG.
5
B).
As is seen from
FIG. 7
, upon assembly, the third tank spaces
131
of the first heat exchanging elements
111
and the seventh tank spaces
141
of the second heat exchanging elements
112
are aligned and connected to one another to constitute a refrigerant flow upstream tank portion
146
. It is to be noted that the rightmost one of the second metal plates
118
as viewed in
FIG. 7
has no opening corresponding to the opening
136
and the leftmost one of the first metal plates
117
has no opening corresponding to the opening
125
.
Furthermore, as is seen from
FIG. 7
, upon assembly, the fourth tank spaces
132
of the first heat exchanging elements
111
and the eighth tank spaces
142
of the second heat exchanging elements
112
are aligned and connected to one another to constitute a refrigerant flow downstream tank portion
147
. It is to be noted that the rightmost one of the second metal plates
118
as viewed in
FIG. 7
has no opening corresponding to the opening
137
and the leftmost one of the first metal plates
117
has no opening corresponding to the opening
126
.
In the following, operation of the stack type evaporator
100
of the invention will be described with reference to
FIGS. 7 and 10
.
Under operation of the associated air conditioner, a liquid-gaseous refrigerant, which has been discharged from an expansion valve (not shown), is led into the inlet tank portion
143
through the inlet pipe connector
114
and the inlet pipe
103
. The refrigerant in the inlet tank portion
143
then flows down into the straight flow passages
120
of the first group heat exchanging elements
111
which are arranged at the left-half (as viewed in
FIG. 7
) and air downstream side of the core unit
105
of the evaporator
100
. The refrigerant in the straight flow passages
120
then flows into a left half part (as viewed in
FIGS. 7 and 10
) of the refrigerant flow upstream tank portion
146
.
The refrigerant led into the left-half part of the refrigerant flow upstream tank portion
146
flows in the portion
146
rightward in the drawing. Then, the refrigerant is led into the U-shaped flow passages
122
of the second group heat exchanging elements
112
which constitute the right-half part of the core unit
105
in the drawings. The refrigerant in the U-shaped flow passages
122
then flows into a right half part of the refrigerant flow downstream tank portion
147
. Then, the refrigerant flows leftward (as viewed in
FIGS. 7 and 10
) in the tank portion
147
and then flows upward into the straight flow passages
121
of the first groups heat exchanging elements
111
. The refrigerant then flows into the outlet tank portion
145
and then flows into a compressor through the outlet pipe connector
115
and the outlet pipe
104
.
During the above-mentioned flow in the core unit
105
, the refrigerant makes a heat exchanging with the air which flows through the core unit
105
in the direction of the arrow “α” of the drawings. Thus, the air is cooled by a certain degree.
As is easily understood from
FIG. 10
, due to the above-mentioned unique arrangement of the refrigerant flow passages, the refrigerant can flow evenly in both the air flow downstream part and the air flow upstream part of the core unit
105
. That is, the flow passages
120
through which the lowest temperature refrigerant flows are arranged just behind the flow passages
121
through which the highest temperature refrigerant flows, and the intermediate temperature refrigerant flows in the U-shaped flow passages
122
which extend between the air flow upstream and downstream parts of the core unit
105
.
Furthermore, as is understood from
FIGS. 12 and 13
, under operation, the inside side section “X” of the air flow downstream left-half part of the evaporator
100
is permitted to let a larger amount of liquid-gaseous refrigerant flow therethrough, and the outside section “Y” of the air flow upstream left-half part of the evaporator
100
is permitted to let a larger amount of gaseous refrigerant flow therethrough. It is to be noted that these two sections “X” and “Y” are not overlapped with respect to the direction in which the air “α” flows. This means that a relatively low temperature zone of the flow passages
120
and a relatively high temperature zone of the flow passages
121
are overlapped to each other with respect to the air flowing direction.
Thus, the core unit
105
of the evaporator
100
can have an even temperature distribution therethroughout. This provides the air passing through the core unit
105
with a uniformed temperature distribution, which makes the passengers comfortable. Furthermore, such even temperature distribution of the core unit
105
brings about an effective heat exchanging between the refrigerant flowing in the core unit
105
and the air passing through the core unit
105
.
In each of the right and left half parts (as viewed in
FIGS. 7 and 10
) of the core unit
105
, higher temperature refrigerant flows in the air flow upstream part of the core unit
105
and lower temperature refrigerant flows in the air flow downstream part of the unit
105
. This promotes the uniformed temperature distribution of the air passing through the core unit
105
.
As is described hereinabove, the evaporator
100
of the present invention is so oriented as having the pipe connectors
114
and
115
directed against the air flow. Thus, as is seen from
FIG. 11
, even when the evaporator
100
is arranged in parallel with the dash panel
8
, the connection of the inlet and outlet pipes
103
and
104
to the coupler
2
held by the dash panel
8
is readily and simply made, which brings about a low cost production of the automotive air conditioner as well as a smoothed air flow passing through the evaporator
100
.
Furthermore, since the evaporator
100
has no structure corresponding the side tank portion
7
′ (see
FIG. 28
) possessed by the conventional evaporator
1
′, lowering in heat exchanging performance caused by such side tank portion
7
′ does not occur.
Referring to
FIGS. 14 and 15
, there is shown a first modification
100
A of the evaporator
100
.
In this first modification
100
A, the inlet pipe
103
is connected to a left end portion (as viewed in
FIG. 14
) of the core unit
105
, and the outlet pipe
104
is connected to a right end portion (as viewed in
FIG. 14
) of the core unit
105
. For this arrangement, the inlet tank portion
143
extends throughout the width of the core unit
105
, as shown. That is, in this modification
100
A, the first tank spaces
129
(see
FIG. 7
) of the first heat exchanging elements
111
and the fifth tank spaces
139
of the second heat exchanging elements
112
are connected to constitute the inlet tank portion
143
. The outlet tank portion
145
is arranged at a right half air flow upstream side of the core unit
105
, as shown in the drawing.
As is seen from
FIG. 15
, even when the modified evaporator
100
A is arranged in parallel with the dash panel
8
, the connection of the inlet and outlet pipes
103
and
104
to the coupler
2
is readily and simply made, which brings about a low cost production of the automotive air conditioner and a smoothed air flow passing through the evaporator
100
A.
Referring to
FIGS. 16
to
21
, there is shown a second modification
100
B of the evaporator
100
.
As is seen from
FIGS. 16 and 17
, in this second modification
100
B, refrigerant inlet and outlet pipes
152
and
153
are connected through a connector
154
(see
FIG. 18
) to an upper portion of one side end of the core unit
105
. For this arrangement, the inlet tank portion
143
and the outlet tank portion
145
extend throughout the width of the core unit
105
. That is, the first tank spaces
129
of the first heat exchanging elements
111
and the fifth tank spaces
139
of the second heat exchanging elements
112
are connected to constitute the inlet tank portion
143
, and the second tank spaces
130
of the first heat exchanging elements
111
and the sixth tank spaces
140
of the second heat exchanging elements
112
are connected to constitute the outlet tank portion
145
.
As is seen from
FIGS. 18 and 19
, the connector
154
is secured to the outermost one of the second heat exchanging elements
112
. More specifically, as is seen from
FIG. 19
, the connector
154
is secured to the outside one of the paired recessed metal plates
118
of the element
112
. For this connection, the outside metal plate
118
is formed with two openings
155
and
156
which are respectively communicated with the fifth tank spaces
139
and the sixth tank spaces
140
of the core unit
105
. The inlet and outlet pipes
152
and
153
held by the connector
154
are respectively mated with the openings
155
and
156
of the outside metal plate
118
. The inlet pipe
152
extends to an expansion valve and the outlet pipe
153
extends to a compressor.
As is seen from
FIGS. 20 and 21
, also in this second modification
100
B, under operation, the inside side section “X” of the air flow downstream left-half part of the evaporator
100
B is permitted to let a larger amount of liquid-gaseous refrigerant flow therethrough, and the outside section “Y” of the air flow upstream left-half part of the evaporator
100
B is permitted to let a larger amount of gaseous refrigerant flow therethrough. Like in the case of the above-mentioned evaporator
100
, the two sections “X” and “Y” are not overlapped with respect to the direction in which the air “α” flows. That is, also in this second modification
100
B, a relatively low temperature zone of the flow passages
120
and a relatively high temperature zone of the flow passages
121
are overlapped to each other with respect to the air flowing direction. Thus, the core unit
105
of the evaporator
100
B can have an even temperature distribution therethroughout.
Furthermore, since, in this second modification
100
B (see FIG.
20
), the inlet and outlet pipes
152
and
153
are aligned with the inlet and outlet tank portions
143
and
145
of the core unit
105
, the inflow of the refrigerant into the inlet tank portion
143
and the outflow of the refrigerant from the outlet tank portion
145
are smoothly carried out and thus the refrigerant flow resistance of the evaporator
100
B can be reduced.
Referring to
FIG. 22
, there is shown a third modification
100
C of the evaporator
100
.
Since this modification
100
C is similar in construction to the above-mentioned second modification
100
B, only parts different from those of the second modification
100
B will be described.
That is, as is shown in the drawing, a side plate
119
′ provided with an extra side tank
158
is employed for reducing the dynamic pressure possessed by the refrigerant just fed to the core unit
105
. As shown, a passage
159
defined in the extra side tank
158
has one end connected to the inlet tank portion
143
and the other end connected to the refrigerant inlet pipe
152
. In this case, the dynamic pressure possessed by the refrigerant just fed to the core unit
105
is effectively reduced and thus undesired drift of the refrigerant flow in the flow passages
120
of the first heat exchanging elements
111
is suppressed or at least minimized. Even in this modification
100
C, the refrigerant outlet pipe
153
should be aligned with the outlet tank portion
145
because the gaseous refrigerant flowing in the outlet tank portion
145
is easily affected in flow resistance by the complication in structure of the flow passage as compared with the liquid-gaseous refrigerant fed into the core unit
105
.
Referring to
FIG. 23
, there is shown a third modification
100
D of the evaporator
100
.
As shown, in this fourth modification
100
D, refrigerant inlet and outlet pipes
152
and
153
are connected to laterally opposed ends of the core unit
105
. Furthermore, in this modification
100
D, the outlet tank portion
145
is provided at only one half part of the core unit
105
. That is, the second tank spaces
130
of the first heat exchanging elements
111
located at a right half (as viewed in
FIG. 23
) of the core unit
105
are connected to constitute the outlet tank portion
145
.
The entire contents of Japanese Patent Application P10-317145 (filed Nov. 9, 1998) and Japanese Patent Application P11-189273 (filed Jul. 2, 1999) are incorporated herein by reference.
Although the invention has been described above with reference to an embodiment of the invention and modifications of the same, the invention is not limited to such the embodiment and modifications as described above. Much larger modifications and variations of the invention described above will occur to those skilled in the art, in light of the above teachings.
Claims
- 1. A stack type evaporator comprising:a first mass including first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; a second mass including second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends and a pair of mutually independent tank passages for respective fluid communication with said first and second passages, said second mass being arranged beside said first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis; an inlet tank passage connecting to upper ends of said first passages; an upstream tank passage connecting to lower ends of said first passages and the first ends of said third passages; a downstream tank passage connecting to lower ends of said second passages and the second ends of said third passages; an outlet tank passage connecting to upper ends of said second passages; an inlet pipe connected to said inlet tank passage; and an outlet pipe connected to said outlet tank passage.
- 2. A stack type evaporator as claimed in claim 1, in which said first and second passages of each first heat exchanging element are arranged at downstream and upstream positions with respect to a direction in which air flows through the evaporator, and in which said third passage of each second heat exchanging element comprises a first passage part, a second passage part and a third passage part through which said first and second passage parts are connected, said first and second passage parts being arranged at downstream and upstream positions with respect to the air flowing direction.
- 3. A stack type evaporator as claimed in claim 2, in which said first passages of the first heat exchanging elements and said first passage parts of the second heat exchanging elements are arranged to form a first line, and in which said second passages of the first heat exchanging elements and said second passage parts of the second heat exchanging elements are arranged to form a second line, said second line being positioned more upstream than said first line with respect to the air flowing direction.
- 4. A stack type evaporator as claimed in claim 3, in which said inlet pipe is connected to the upper end of the first passage possessed by the innermost first heat exchanging element, and in which said outlet pipe is connected to the upper end of the second passage possessed by said innermost first heat exchanging element.
- 5. A stack type evaporator as claimed in claim 4, in which said inlet and outlet pipes are projected in a direction against the air flowing direction.
- 6. A stack type evaporator as claimed in claim 5, in which said inlet and outlet pipes are connected to the upper ends of said first and second passages through respective connectors.
- 7. A stack type evaporator as claimed in claim 5, in which said inlet and outlet pipes are connected to the upper ends of said first and second passages through respective first and second connectors, said first connector having a passage by which said inlet pipe is connected to the upper end of said first passage, said second connector having a passage by which said outlet pipe is connected to the upper end of said second passage.
- 8. A stack type evaporator as claimed in claim 3, in which said inlet tank passage extends to the outermost second heat exchanging element, in which said inlet pipe is connected to the extended intake tank passage possessed by said outermost second heat exchanging element, and in which said outlet pipe is connected to the upper end of the second passage possessed by the outermost first heat exchanging element.
- 9. A stack type evaporator as claimed in claim 3, in which said inlet and outlet tank passages extend to the outermost second heat exchanging element, and in which said inlet and outlet pipes are respectively connected to the extended inlet and outlet tank passages possessed by said outermost second heat exchanging element.
- 10. A stack type evaporator as claimed in claim 9, in which said inlet and outlet pipes are aligned with said inlet and outlet tank passages, respectively.
- 11. A stack type evaporator as claimed in claim 10, in which said outermost second heat exchanging element is provided with a connector through which said inlet and outlet pipes are connected to said inlet and outlet tank passages.
- 12. A stack type evaporator as claimed in claim 11, in which said outermost second heat exchanging element is provided further with an extra side tank for reducing a dynamic pressure possessed by a refrigerant just fed into the inlet tank passage from said inlet pipe.
- 13. A stack type evaporator as claimed in claim 12, in which said extra side tank has therein a passage which has one end connected to the inlet tank passage and the other end connected to said inlet pipe held by said connector.
- 14. A stack type evaporator as claimed in claim 3, in which said inlet tank passage extends to the outermost second heat exchanging element, in which said inlet pipe is connected to the extended intake tank passage possessed by said outermost second heat exchanging element, and in which said outlet pipe is connected to the upper end of the second passage possessed by the outermost first heat exchanging element.
- 15. A stack type evaporator as claimed in claim 1, further comprising:first and second side plates respectively attached to outside ones of the heat exchanging elements of said first and second masses; and a plurality of heat radiation fins each being interposed between adjacent two of the first and second heat exchanging elements.
- 16. A stack type evaporator as claimed in claim 1, in which each of said first and second heat exchanging elements comprises two identical recessed metal plates, said two metal plates being coupled in a face-to-face connecting manner to define therebetween a hermetically sealed liquid flow space.
- 17. In a motor vehicle having an engine room and a passenger room which are partitioned by a dash panel, an arrangement comprising:an evaporator which includes a first mass including first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; a second mass including second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends and a pair of mutually independent tank passages for respective fluid communication with said first and second passages, said second mass being arranged just beside said first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis; an inlet tank passage connecting to upper ends of said first passages; an upstream tank passage connecting to lower ends of said first passages and the first ends of said third passages; a downstream tank passage connecting to lower ends of said second passages and the second ends of said third passages; an outlet tank passage connecting to upper ends of said second passages; an inlet pipe connected to said inlet tank passage; and an outlet pipe connected to said outlet tank passage; means for placing said evaporator in such a manner that the evaporator is arranged in parallel with said dash panel and that said inlet tank passage and said upstream tank passage are positioned away from said dash panel as compared with said outlet tank passage and said downstream tank passage; and means for producing an air flow through said evaporator in a direction from said dash panel toward said evaporator.
Priority Claims (2)
Number |
Date |
Country |
Kind |
10-317145 |
Nov 1998 |
JP |
|
11-189273 |
Jul 1999 |
JP |
|
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AU |
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EP |
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Sep 1998 |
EP |
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Jan 1987 |
JP |
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JP |
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Mar 1995 |
JP |
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