Refrigerant / heating medium heat exchanger, and vehicle air conditioning system employing same

Abstract

[Problem] To provide a refrigerant / heating medium heat exchanger capable of varying the temperature of an outflowing liquid heating medium by means of a heat exchanger, and a vehicle air conditioning system employing same. [Solution] A refrigerant / heating medium heat exchanger (1) for performing heat exchange between a refrigerant and a liquid heating medium comprises: a refrigerant inflow port (11) through which the refrigerant flows in; a refrigerant outflow port (12) through which the refrigerant flows out; a refrigerant flow path (13) for connecting the refrigerant inflow port (11) and the refrigerant outflow port (12); a heating medium inflow port (21) enabling the liquid heating medium to flow in; a heating medium outflow port (22) enabling the liquid heating medium to flow out; a heating medium flow path (23) which connects the heating medium inflow port (21) and the heating medium outflow port (22) and is provided so as to run alongside the refrigerant flow path (13); and an intermediate heating medium inflow port (25) which communicates with the heating medium flow path (23), is provided between the heating medium inflow port (21) and the heating medium outflow port (22) as seen along a flow of the liquid heating medium, and enables the liquid heating medium to flow in.

Description

[Document Name] SPECIFICATION[Title of the Invention] Refr igerant / heating medium heat exchanger, and vehicle air conditioning system employing same[Technical Field]

[0001] The present invention relates to a refrigerant / heating medium heat exchanger for performing heat exchange between a refrigerant and a liquid heating medium, and to a vehicle air conditioning system employing same.[Background Art]

[0002] A stacked heat exchanger for performing heat exchange between a refrigerant and cooling water is conventionally known (see Patent Document 1) . This heat exchanger is formed by stacking multiple heat transfer plates, with a refrigerant passage for a flow of a refrigerant and a cooling water passage for a flow of cooling water, which are formed between two heat transfer plates adjacent in a stacking direction, being alternately arranged in a stacking direction. The refrigerant passage therefore branches into multiple rows within the stack, and the cooling water passage also branches into multiple rows within the stack.

[0003] Furthermore, the heat transfer plate arranged at one end in the stacking direction is provided with: a refrigerant inflow port through which the refrigerant flows into the refrigerant passage from the outside; a refrigerant outflow port through which the refrigerant flows to the outside from the refrigerant passage; a cooling water inflow port through which the cooling water flows into the cooling water passage from the outside; and a cooling water outflow port through which the cooling water flows to the outside from the cooling water passage.

[0004] The refrigerant that has flowed in from the refrigerant inflow port therefore passes through the refrigerant passage which branches inside the stack and thenflows out from the refrigerant outflow port, while the cooling water that has flowed in from the cooling water inflow port passes through the cooling water passage which branches inside the stack and then flows out from the cooling water outflow port, and the refrigerant and the cooling water undergo heat exchange as they pass through the respective branched passages (refrigerant passage and cooling water passage) .[Prior Art Documents][Patent Documents]

[0005] [Patent Document 1] JP 2017-15278 A[Summary of the Invention][Problem to be Solved by the Invention]

[0006] In the conventional heat exchanger, however, the cooling water inflow port communicates with a starting end position of the cooling water passage, and the cooling water outflow port communicates with a terminal position of the cooling water passage, and the refrigerant and the cooling water undergo heat exchange using the whole interior of the stack, after which the cooling water is supplied to a heater core in a hot water cycle, so the length of heat exchange of the refrigerant and the cooling water is fixed, making it impossible to vary the temperature of the outflowing cooling water (liquid heating medium) by means of the heat exchanger, which thus limits the purposes of use.

[0007] The present invention has been devised in light of this situation, and the main problem addressed thereby lies in providing a refrigerant / heating medium heat exchanger capable of varying the temperature of an outflowing liquid heating medium by means of a heat exchanger, and a vehicle air conditioning system employing same.[Means for Solving the Problem]

[0008] In order to solve the problem above, a refrigerant / heating medium heat exchanger (1) according to the present invention performs heat exchange between a refrigerant and a liquid heating medium and is characterized by comprising: a refrigerant inflow port (11) through which a refrigerant flows in; a refrigerant outflow port (12) through which the refrigerant flows out; a refrigerant flow path (13) for connecting the refrigerant inflow port (11) and the refrigerant outflow port (12) ; a heating medium inflow port (21) enabling a liquid heating medium to flow in; a heating medium outflow port (22) enabling the liquid heating medium to flow out; a heating medium flow path (23) which connects the heating medium inflow port (21) and the heating medium outflow port (22) and is provided so as to run alongside the refrigerant flow path (13) ; and an intermediate heating medium inflow port (25) which communicates with the heating medium flow path (23), is provided between the heating medium inflow port (21) and the heating medium outflow port (22) as seen along a flow of the liquid heating medium, and enables the liquid heating medium to flow in.

[0009] Accordingly, the intermediate heating medium inflow port is provided between the heating medium inflow port and the heating medium outflow port as seen along a flow of the liquid heating medium, so an amount of heat exchange of the liquid heating medium flowing in from the heating medium inflow port and flowing out from the heating medium outflow port is different from an amount of heat exchange of the liquid heating medium flowing in from the intermediate heating medium inflow port and flowing out from the heating medium outflow port. The temperature of the liquid heating medium flowing out from the heating medium outflow port can therefore be regulated by adjusting the proportions of the amount of liquid heating medium flowing in from the heating medium inflow port and the amount of liquid heating medium flowing in from the intermediate heating medium inflow port.

[0010] That is to say, the temperature of the liquid heating medium which is supplied in order to cool a heat-generating element can be varied on the basis of theamount of heat generated by the heat-generating element at the time of cooling the heat-generating element, by adjusting a flow rate ratio of the liquid heating medium flowing in from the heating medium inflow port and the liquid heating medium flowing in from the intermediate heating medium inflow port, and it is furthermore possible to vary the temperature of the liquid heating medium which is supplied in order to heat an object to be heated, even if there is a change in the required heating amount of the object to be heated.

[0011] The abovementioned refrigerant / heating medium heat exchanger may be configured by a heat exchanger having a stacked structure. That is to say, the refrigerant / heating medium heat exchanger (1) may be constructed by alternately stacking refrigerant circulation layers (16) leading to the refrigerant inflow port (11) and the refrigerant outflow port (12) , and heating medium circulation layers (26) leading to the heating medium inflow port (21) , the heating medium outflow port (22) , and the intermediate heating medium inflow port (25) ; the refrigerant flow path (13) may be formed by the respective refrigerant circulation layers (16) , and the heating medium flow path (23) may be formed by the respective heating medium circulation layers (26) .

[0012] In this configuration, the refrigerant circulation layers and heating medium circulation layers are alternately stacked, so it is possible to ensure a large area for heat exchange between the refrigerant and the liquid heating medium, enabling better heat exchange efficiency.

[0013] The abovementioned refrigerant / heating medium heat exchanger can be utilized in many types of vehicle air conditioning systems.

[0014] For example, a vehicle air conditioning system may be configured so that an outflow port of an expansion valve (46) for decompressing and expanding the refrigerant is connected to the refrigerant inflow port (11) , the refrigerantwhich has been decompressed and expanded by the expansion valve (46) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a first heat-generating element heat sink (52) for absorbing heat of a first heat-generating element (51), a branch portion (DI) provided on an outflow side of the first heat-generating element heat sink (52), and branch flow paths (53a, 53b) which branch at the branch portion (DI), and the vehicle air conditioning system comprises at least one of: an integrated pump (55) which is provided in a pathway (54) running from the heating medium outflow port (22) to the branch portion (DI) and delivers the liquid heating medium, and separate flow pumps (55a, 55b) respectively provided in the branch flow paths (53a, 53b).

[0015] Furthermore, the vehicle air conditioning system may be configured so that a compressor (61) is connected to the refrigerant inflow port (11), the refrigerant compressed by the compressor (61) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a passenger compartment-internal radiator (36) disposed in an airflow space (34) of an air conditioning unit (30), a branch portion (D2) provided on an outflow side of the passenger compartment-internal radiator (36), and branch flow paths (71a, 71b) which branch at the branch portion (D2) , and the vehicle air conditioning system comprises at least one of: an integrated pump (73) which is provided in a pathway (72) running from the heating medium outflow port (22) to the branch portion (D2) and delivers the liquid heating medium, and separate flow pumps (73a, 73b) respectively provided in the branch flow paths (71a, 71b).

[0016] In addition, the vehicle air conditioning system may be configured so that an outflow port of an expansion valve (85) for decompressing and expanding the refrigerant is connected to the refrigerant inflow port (11), the refrigerantwhich has been decompressed and expanded by the expansion valve (85) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a passenger compartment-internal heat sink (35) disposed in an airflow space (34) of an air conditioning unit (30), a branch portion (D3) provided on an outflow side of the passenger compartment-internal heat sink (35), and branch flow paths (91a, 91b) which branch at the branch portion (D3) , and the vehicle air conditioning system comprises at least one of: an integrated pump (93) which is provided in a pathway (92) running from the heating medium outflow port (22) to the branch portion (D3) and delivers the liquid heating medium, and separate flow pumps (93a, 93b) respectively provided in the branch flow paths (91a, 91b).[Effects of the Invention]

[0017] According to the present invention as described above, the intermediate heating medium inflow port enabling the liquid heating medium to flow in is provided between the heating medium inflow port and the heating medium outflow port as seen along a flow of the liquid heating medium, and it is therefore possible to provide a refr igerant / heat ing medium heat exchanger capable of varying the temperature of a supplied liquid heating medium on the basis of the amount of heat generated by a heat-generating element or the required heating amount of an object to be heated, and also to provide a vehicle air conditioning system employing same.[Brief Description of the Drawings]

[0018] [Fig. 1] shows a first embodiment of the refrigerant / heating medium heat exchanger according to the present invention, where (a) is an oblique view of the heat exchanger simultaneously showing flows of refrigerant and liquid heating medium, (b) is a diagram showing, for expediency, only the flow of refrigerant through the heat exchanger in (a), and (c) is a diagram showing, for expediency,only the flow of liquid heating medium through the heat exchanger in (a) .[Fig. 2] shows heat transfer plates used when the refrigerant / heating medium heat exchanger according to the present invention is configured by a stacked heat exchanger, where (a) is a plan view of a refrigerant heat transfer plate with the flow of refrigerant added, also shown together with a cross section along the line A-A, a cross section along the line B~B, and a cross section along the line C-C, and (b) is a plan view of a heating medium heat transfer plate with the flow of liquid heating medium added, also shown together with a cross section along the line A~A, a cross section along the line B~B, and a cross section along the line C-C.[Fig. 3] is a partial cutaway view of a refrigerant / heating medium heat exchanger in which the refrigerant heat transfer plates and heating medium heat transfer plates in fig. 2 are alternately stacked, where (a) is a view in cross section taken along the line A-A in fig. 2, (b) is a view in cross section taken along the line B-B in fig. 2, and (c) is a view in cross section taken along the line C-C in fig. 2.[Fig. 4] illustrates another example of use of the first embodiment of the refrigerant / heating medium heat exchanger according to the present invention, where (a) is an oblique view of the heat exchanger simultaneously showing flows of refrigerant and liquid heating medium, (b) is a diagram showing, for expediency, only the flow of refrigerant through the heat exchanger in (a) , and (c) is a diagram showing, for expediency, only the flow of liquid heating medium through the heat exchanger in (a) .[Fig. 5] shows heat transfer plates used when the refrigerant / heating medium heat exchanger shown in fig. 4 is configured by a stacked heat exchanger, where (a) is a plan view of a refrigerant heat transfer plate with the flow of refrigerant added, and (b) is a plan view of a heating medium heat transfer plate with the flow of liquid heating medium added.[Fig. 6] is a partial cutaway view of a refrigerant / heating medium heat exchanger in which the refrigerant heat transfer plates and heating medium heat transferplates in fig. 5 are alternately stacked, where (a) is a view in cross section taken along the line A-A in fig. 5, (b) is a view in cross section taken along the line B~B in fig. 5, and (c) is a view in cross section taken along the line C-C in fig. 5.[Fig. 7] illustrates a further example of use of the first embodiment of the refrigerant / heating medium heat exchanger according to the present invention, where (a) is an oblique view of the heat exchanger simultaneously showing flows of refrigerant and liquid heating medium, (b) is a diagram showing, for expediency, only the flow of refrigerant through the heat exchanger in (a) , and (c) is a diagram showing, for expediency, only the flow of liquid heating medium through the heat exchanger in (a) .[Fig. 8] shows heat transfer plates used when the refrigerant / heating medium heat exchanger shown in fig. 7 is configured by a stacked heat exchanger, where(a) is a plan view of a refrigerant heat transfer plate with the flow of refrigerant added, and (b) is a plan view of a heating medium heat transfer plate with the flow of liquid heating medium added.[Fig. 9] is a partial cutaway view of a refrigerant / heating medium heat exchanger in which the refrigerant heat transfer plates and heating medium heat transfer plates in fig. 8 are alternately stacked, where (a) is a view in cross section taken along the line A-A in fig. 8, (b) is a view in cross section taken along the line B-B in fig. 8, and (c) is a view in cross section taken along the line C-C in fig. 8.[Fig. 10] shows a variant example of the first embodiment of the refrigerant / heating medium heat exchanger according to the present invention, where (a) is a diagram showing, for expediency, only the flow of refrigerant, and(b) is a diagram showing, for expediency, only the flow of liquid heating medium.[Fig. 11] is a partial cutaway view of the refrigerant / heating medium heat exchanger shown in fig. 10 when a stacked heat exchanger is constructed using the same heat transfer plates (refrigerant heat transfer plates, heating medium heat transfer plates) as in fig. 2, where (a) is a cross section taken along the lineA-A in fig. 2, (b) is a cross section taken along the line B-B in fig. 2, and (c) is a cross section taken along the line C~C in fig. 2.[Fig. 12] shows a first embodiment of a vehicle air conditioning system according to the present invention.[Fig. 13] shows a variant example of the first embodiment of the vehicle air conditioning system.[Fig. 14] shows another variant example of the first embodiment of the vehicle conditioning system.[Fig. 15] shows a second embodiment of a vehicle air conditioning system according to the present invention.[Fig. 16] shows a variant example of the second embodiment of the vehicle air conditioning system.[Fig. 17] shows another variant example of the second embodiment of the vehicle conditioning system.[Fig. 18] shows a third embodiment of a vehicle air conditioning system according to the present invention.[Fig. 19] shows a variant example of the third embodiment of the vehicle air conditioning system.[Fig. 20] shows another variant example of the third embodiment of the vehicle conditioning system.[Embodiments of the Invention]

[0019] Embodiments of the present invention will be described below with the aid of the drawings.(First embodiment of heat exchanger)A first embodiment of a refrigerant / heating medium heat exchanger 1 according to the present invention is illustrated in fig. 1-3.

[0020] The refrigerant / heating medium heat exchanger 1 is a heat exchanger for performing heat exchange between a refrigerant and a liquid heating medium, and,as shown in fig. 1, comprises: a refrigerant inflow port 11 through which the refrigerant flows in; a refrigerant outflow port 12 through which the refrigerant flows out; a refrigerant flow path 13 for connecting the refrigerant inflow port 11 and the refrigerant outflow port 12, and also comprises: a heating medium inflow port 21 enabling the liquid heating medium to flow in; a heating medium outflow port 22 enabling the liquid heating medium to flow out; and a heating medium flow path 23 which connects the heating medium inflow port 21 and the heating medium outflow port 22 and is provided so as to run alongside the refrigerant flow path 13.

[0021] In this embodiment, the refrigerant / heating medium heat exchanger 1 furthermore comprises an intermediate heating medium inflow port 25 which communicates with the heating medium flow path 23, is provided between the heating medium inflow port 21 and the heating medium outflow port 22 as seen along a flow of the liquid heating medium, and enables the liquid heating medium to flow in.

[0022] The form of the refrigerant / heating medium heat exchanger 1 does not particularly matter, provided that it is configured to perform heat exchange between a refrigerant and a liquid heating medium, but it is preferably a stacked heat exchanger in which multiple heat transfer plates 5 are stacked to allow alternating flows of refrigerant and liquid heating medium, in order to perform efficient heat exchange between the refrigerant and the liquid heating medium.

[0023] That is to say, the refrigerant / heating medium heat exchanger 1 is constructed by alternately stacking refrigerant heat transfer plates 100 and heating medium heat transfer plates 200 shown in fig. 2.

[0024] As shown in fig. 2(a), in the refrigerant heat transfer plate 100, a bonding margin 101 for bonding the heat transfer plates 5, which are adjacent in a stacking direction, is formed on a peripheral edge of a metal plate formed a rectangularshape, and an area inward therefrom is indented so that a refrigerant flow path recess 102 is formed. A protrusion 103 extending in a longitudinal direction from one longitudinal end to the vicinity of another longitudinal end is formed offset to one side from the centre in a short-side direction of the refrigerant flow path recess 102. Accordingly, the refrigerant flow path recess 102 is formed so that a relatively narrow refrigerant outward path recess 102a and a relatively wide refrigerant return path recess 102b extending longitudinally communicate on said other longitudinal end side.

[0025] A refrigerant inflow hole 104 for allowing an inflow of the refrigerant from the outside is provided in the vicinity of said one longitudinal end of the refrigerant outward path recess 102a, close to a corner portion of the bonding margin 101. Furthermore, a refrigerant outflow hole 105 for allowing an outflow of the refrigerant to the outside is provided in the vicinity of said one longitudinal end of the refrigerant return path recess 102b, close to a corner portion of the bonding margin 101.

[0026] In addition, a heating medium inflow hole 106 and a heating medium outflow hole 107 are provided in the vicinity of said other longitudinal end of the refrigerant heat transfer plate 100, close to corner portions of the bonding margin 101, and an intermediate heating medium inflow hole 110 is furthermore formed between the refrigerant outflow hole 105 and the protrusion 103 in the vicinity of said one longitudinal end. The heating medium inflow hole 106, heating medium outflow hole 107, and intermediate heating medium inflow hole 110 are respectively formed on elevated portions 106a, 107a, 110a which are elevated from the refrigerant flow path recess 102.

[0027] In a state in which the heat transfer plates 5 (heating medium heat transfer plates 200) which are adjacent in the stacking direction have been assembled, the protrusion 103 and each of the elevated portions 106a, 107a, 110a on therefrigerant heat transfer plate 100 may be brazed while abutting a back face of the adjacent heat transfer plate 5, and, in the brazed state, the heating medium inflow hole 106, the heating medium outflow hole 107, and the intermediate heating medium inflow hole 110 do not communicate with the refrigerant flow path recess 102.

[0028] Meanwhile, as shown in fig. 2(b), in the heating medium heat transfer plate 200, a bonding margin 201 for bonding the heat transfer plates 5, which are adjacent in the stacking direction, is formed on a peripheral edge of a metal plate formed a rectangular shape, and an area inward therefrom is indented so that a heating medium flow path recess 202 is formed.

[0029] A protrusion 203 extending in the longitudinal direction from said other longitudinal end to the vicinity of said one longitudinal end is formed offset to another side from the centre in a short-side direction of the heating medium flow path recess 202. Accordingly, the heating medium flow path recess 202 is formed so that a relatively wide heating medium outward path recess 202a and a relatively narrow heating medium return path recess 202b extending longitudinally communicate on said one longitudinal end side.

[0030] A heating medium inflow hole 206 for allowing an inflow of liquid heating medium from the outside is provided in the vicinity of said other longitudinal end of the heating medium outward path recess 202a, close to a corner portion of the bonding margin 201. Furthermore, a heating medium outflow hole 207 for allowing an outflow of the liquid heating medium to the outside is provided in the vicinity of said other longitudinal end of the heating medium return path recess 202b, close to a corner portion of the bonding margin 201.

[0031] In addition, a refrigerant inflow hole 204 and a refrigerant outflow hole 205 are formed in the vicinity of said one longitudinal end of the heating mediumheat transfer plate 200, close to a corner portion of the bonding margin 201. Furthermore, an intermediate heating medium inflow hole 210 is provided in communication with the heating medium flow path recess 202 in the vicinity of said one longitudinal end, on a line of extension of the protrusion 203 between the refrigerant inflow hole 204 and the refrigerant outflow hole 205. The refrigerant inflow hole 204 and the refrigerant outflow hole 205 are formed on elevated portions 204a, 205a which are elevated from the heating medium flow path recess 202.

[0032] In a state in which the heat transfer plates 5 (refrigerant heat transfer plates 100) which are adjacent in the stacking direction have been assembled, the protrusion 203 and each of the elevated portions 204a, 205a on the heating medium heat transfer plate 200 may be brazed while abutting a back face of the adjacent heat transfer plate 5, and, in the brazed state, the refrigerant inflow hole 204 and the refrigerant outflow hole 205 do not communicate with the heating medium flow path recess 202.

[0033] As also shown in fig. 3, the heat transfer plate 5 disposed at one end in the stacking direction (the heat transfer plate disposed at the uppermost end, e. g. , the heating medium heat transfer plate 200) is provided with: the refrigerant inflow port 11 through which the refrigerant flows in from the outside, the refrigerant outflow port 12 through which the refrigerant flows out, the heating medium inflow port 21 through which the liquid heating medium flows in from the outside, and the heating medium outflow port 22 through which the liquid heating medium flows out. The intermediate heating medium inflow port 25 is furthermore provided in the vicinity of the bonding margin 201 at said one end in the longitudinal direction, between the refrigerant inflow port 11 and the refrigerant outflow port 12 of the heat transfer plate disposed at said one end in the stacking direction.

[0034] A positional relationship such as shown in fig. 3(c) is obtained by alternately stacking the abovementioned refrigerant heat transfer plates 100 and heating medium heat transfer plates 200. Specifically:(i) The refrigerant inflow holes 104 in each of the refrigerant heat transfer plates 100 are at positions aligned with the refrigerant inflow holes 204 in the heating medium heat transfer plates 200, and communicate with the refrigerant inflow port 11.(ii) The refrigerant outflow holes 105 in the refrigerant heat transfer plates 100 are at positions aligned with the refrigerant outflow holes 205 in the heating medium heat transfer plates 200, and communicate with the refrigerant outflow port 12.(iii) The intermediate heating medium inflow holes 110 in the refrigerant heat transfer plates 100 are at positions aligned with the intermediate heating medium inflow holes 210 in the heating medium heat transfer plates 200, and communicate with the intermediate heating medium inflow port 25.

[0035] Furthermore, a positional relationship such as shown in fig. 3(a) is also obtained. Specifically:(iv) The heating medium inflow holes 106 in the refrigerant heat transfer plates 100 are at positions aligned with the heating medium inflow holes 206 in the heating medium heat transfer plates 200, and communicate with the heating medium inflow port 21.(v) The heating medium outflow holes 107 in the refrigerant heat transfer plates 100 are at positions aligned with the heating medium outflow holes 207 in the heating medium heat transfer plates 200, and communicate with the heating medium outflow port 22.

[0036] Accordingly, when the refrigerant heat transfer plates 100 and the heating medium heat transfer plates 200 are used to form an alternating stack while the respective bonding margins 101, 201 thereof are butted together, switchbackrefrigerant circulation layers 16 are formed from the refrigerant inflow hole 104 to the refrigerant outflow hole 105 between the refrigerant flow path recesses 102 of the refrigerant heat transfer plates 100 and the back faces of the heating medium heat transfer plates 200, as shown in fig. 3. The refrigerant circulation layers 16 do not communicate with the heating medium inflow holes 106, the heating medium outflow holes 107, or the intermediate heating medium outflow holes 108, and therefore the refrigerant that has flowed in from the refrigerant inflow hole 104 passes through the relatively narrow outward path, then makes a U-turn and passes through the relatively wide return path, flowing out from the refrigerant outflow hole 105, as shown in fig. 2.

[0037] Furthermore, switchback heating medium circulation layers 26 are formed from the heating medium inflow hole 206 to the heating medium outflow hole 207 between the heating medium flow path recesses 202 of the heating medium heat transfer plates 200 and the back faces of the refrigerant heat transfer plates 100. The heating medium circulation layers 26 do not communicate with the refrigerant inflow holes 204 or the refrigerant outflow holes 205, and therefore the liquid heating medium that has flowed in from the heating medium inflow hole 206 passes through the relatively wide outward path, then makes a U-turn and passes through the relatively narrow return path, flowing out from the heating medium outflow hole 207. Furthermore, the heating medium circulation layers 26 also each communicate with the intermediate heating medium inflow holes 210, so the liquid heating medium that has flowed in from the heating medium inflow holes 206 flows out from the heating medium outflow holes 207 together with the liquid heating medium that has flowed in from the intermediate heating medium inflow holes 210.

[0038] The refrigerant heat transfer plates 100 and the heating medium heat transfer plates 200 are alternately stacked, and therefore a plurality of the refrigerant circulation layers 16 are provided in parallel between the refrigerant inflow port 11 and the refrigerant outflow port 12, and a plurality of the heating mediumcirculation layers 26 are furthermore provided in parallel between the heating medium inflow port 21, the heating medium outflow port 22, and the intermediate heating medium inflow port 25. Accordingly, the refrigerant flow path 13 for connecting the refrigerant inflow port 11 and the refrigerant outflow port 12 is formed by means of the respective refrigerant circulation layers 16, and the refrigerant that has flowed in from the refrigerant inflow port 11 branches into each of the refrigerant circulation layers 16 and then merges to flow out from the refrigerant outflow port 12. Furthermore, the heating medium flow path 23 for connecting the heating medium inflow port 21 and the heating medium outflow port 22 is formed by means of the respective heating medium circulation layers 26, and the heating medium that has flowed in from the heating medium inflow port 21 branches into each of the refrigerant circulation layers 26, merges with the liquid heating medium that has flowed in from the intermediate heating medium inflow port 25 part way along, and then flows out from the heating medium outflow port 22.

[0039] Accordingly, the refrigerant / heating medium heat exchanger 1 performs heat exchange between the refrigerant and the liquid heating medium via the heat transfer plates 5 between the adjacent layers, and the flow of refrigerant in the refrigerant circulation layers 16 and the flow of liquid heating medium in the heating medium circulation layers 26 are moreover counter flows, so it is possible to perform efficient heat exchange between the refrigerant and the liquid heating medium.

[0040] Moreover, the position of the protrusion 103 of the refrigerant heat transfer plate 100 and the position of the protrusion 203 of the heating medium heat transfer plate 200 are offset to opposite sides from the centre in the short-side direction of the heat transfer plates 5, so the top portions of the protrusions 103, 203 of the respective heat transfer plates are securely brazed while abutting the back face of the adjacent heat transfer plate 5. Consequently, it is possibleto enhance the strength of the heat exchanger and it is furthermore possible to reliably avoid short-circuiting the flow of refrigerant or liquid heating medium.

[0041] Furthermore, the intermediate heating medium inflow holes 110, 210 are respectively formed in the refrigerant heat transfer plate 100 and the heating medium heat transfer plate 200 of the refrigerant / heating medium heat exchanger 1 described above, and the intermediate heating medium inflow port 25 is able to communicate with the heating medium circulation layers 26 via the respective intermediate heating medium inflow holes 110, 210, so the liquid heating medium which flows through the heating medium circulation layers 26 can flow in not only from the heating medium inflow port 21 but also from the intermediate heating medium inflow port 25.

[0042] The intermediate heating medium inflow port 25 communicates with switchback portions (positioned on the line of extension of the protrusions 203) of the heating medium circulation layers 26 via the intermediate heating medium inflow holes 110, 210, and therefore a passage length (heat exchange length) running from the intermediate heating medium inflow hole 210 to the heating medium outflow hole 207 in each heating medium circulation layer 26 is roughly half of the passage length (heat exchange length) running from the heating medium inflow hole 206 to the heating medium outflow hole 207, and when the liquid heating medium is cooled by the refrigerant, a temperature difference between the liquid heating medium at the intermediate heating medium inflow port 25 and the liquid heating medium at the heating medium outflow port 22 is approximately half of the temperature difference between the liquid heating medium at the heating medium inflow port 21 and the liquid heating medium at the heating medium outflow port 22. Furthermore, when the liquid heating medium is heated by the refrigerant, the temperature difference between the liquid heating medium at the heating medium outflow port 22 and liquid heating medium at the intermediate heating medium inflow port 25 is also approximately half of the temperature difference betweenthe liquid heating medium at the heating medium outflow port 22 and the liquid heating medium at the heating medium inflow port 21.The temperature of the liquid heating medium flowing out from the heating medium outflow port 22 can therefore be regulated by adjusting the proportions of the amount of liquid heating medium flowing in from the heating medium inflow port 21 and the amount of liquid heating medium flowing in from the intermediate heating medium inflow port 25.

[0043] It should be noted that the example above relates to an example in which the intermediate heating medium inflow port 25 is provided at a position approximately halfway between the heating medium inflow port 21 and the heating medium outflow port 22, but the position of the intermediate heating medium inflow port 25 is not limited to such a position, and the position at which it is formed should be suitably adjusted according to the required intermediate temperature.

[0044] Furthermore, the amount of heat exchange between the refrigerant and the liquid heating medium may be adjusted by switching the inflow port through which the liquid heating medium flows in, using the refrigerant / heating medium heat exchanger 1 described above.That is to say, when a sufficient amount of heat exchange between the refrigerant and the liquid heating medium is to be maintained in the refrigerant / heating medium heat exchanger 1, the inflow of liquid heating medium from the intermediate heating medium inflow port 25 should be stopped, and all of the liquid heating medium should be made to flow in through the heating medium inflow port 21, as shown in fig. 4-6. This makes it possible to increase the amount of heat exchange between the refrigerant and the liquid heating medium.

[0045] Furthermore, when the amount of heat exchange in the refrigerant / heating medium heat exchanger 1 is to be reduced, the inflow of liquid heating medium from the heating medium inflow port 21 should be stopped, and all of the liquid heatingmedium should be made to flow in through the intermediate heating medium inflow port 25, as shown in fig. 7-9. This makes it possible to reduce the amount of heat exchange between the refrigerant and the liquid heating medium, and the amount of heat exchange between the refrigerant and the liquid heating medium is therefore restricted.

[0046] (Variant example of first embodiment of heat exchanger)The configuration described above relates to an example in which the refrigerant inflow port 11 and refrigerant outflow port 12, and the heating medium inflow port 21 and heating medium outflow port 22, plus the intermediate heating medium inflow port 25 are provided in the heat transfer plate 5 disposed at one end in the stacking direction of the refrigerant / heating medium heat exchanger 1, but as shown in fig. 10 and 11, the refrigerant inflow port 11 and the refrigerant outflow port 12 may be provided in the heat transfer plate 5 (e. g. , the heating medium heat transfer plate 200) disposed at said one end in the stacking direction of the refrigerant / heating medium heat exchanger 1, and the heating medium inflow port 21 and heating medium outflow port 22, plus the intermediate heating medium inflow port 25 may be provided in the heat transfer plate 5 (e. g. , the refrigerant heat transfer plate 100) disposed at the other end in the stacking direction. The same action and effects are also achieved with such a configuration.

[0047] A vehicle air conditioning system S employing the abovementioned refrigerant / heating medium heat exchanger 1 will be described next.

[0048] (First embodiment of vehicle air conditioning system)Fig. 12 shows a first embodiment of the vehicle air conditioning system S employing the refrigerant / heating medium heat exchanger 1 (heat exchanger comprising the refrigerant inflow port 11, refrigerant outflow port 12, heating medium inflow port 21, heating medium outflow port 22, and intermediate heating medium inflow port 25) shown in fig. 1 or 10.

[0049] In this example, the vehicle air conditioning system S comprises: a refrigerant cycle 40 which is a heat pump cycle for regulating the temperature of air in an airflow space 34 within an air conditioning unit 30 mounted in a vehicle; and a heating medium cycle 50 for cooling a heat-generating element.

[0050] In the air conditioning unit 30 which will be described first, an indoor / outdoor air switching device 31 is provided on the side of the air conditioning unit 30 furthest upstream. The indoor / outdoor air switching device 31 is configured so that an indoor air introduction port 31a and an outdoor air introduction port 31b are selectively opened by means of an intake door 32. The indoor air or outdoor air which is selectively introduced into the air conditioning unit 30 is drawn in by rotation of a blower 33 and delivered to a passenger compartment-internal heat sink 35 and a passenger compartment-internal radiator 36 disposed in the airflow space 34 where the indoor air or outdoor air undergoes heat exchange and is supplied into a vehicle compartment from a desired blowout port 37a-37c. The passenger compartment-internal heat sink 35 is also referred to as an evaporator, and the passenger compartment-internal radiator 36 is also referred to as a heater core.

[0051] The passenger compartment-internal radiator 36 is disposed downstream of the passenger compartment-internal heat sink 35 in a direction of air flow through the air conditioning unit 30, and a damper 38 is provided upstream of the passenger compartment- internal radiator 36 in the direction of air flow. The damper 38 can be displaced from a position of maximum air throughput of the passenger compartment- internal radiator 36 (heating position: 100% degree of opening) to a position of minimum air throughput (cooling position: 0% degree of opening), and the proportions of air passing through and air bypassing the passenger compartment- internal radiator 36 can be adjusted by adjusting the degree of opening.

[0052] It should be noted that the damper 38 is also referred to as an air mix door. Furthermore, an electrical heat-generating type of heating device (PTC) which is not depicted may be disposed downstream of the passenger compartment- internal radiator 36 within the air conditioning unit 30.

[0053] The refrigerant cycle 40 in the vehicle air conditioning system S internally circulates the refrigerant and comprises: a compressor 41 for feeding out the refrigerant; the passenger compartment- internal radiator 36 which receives an inflow of the refrigerant fed out from the compressor 41; a first expansion valve 42 which allows the passage of the refrigerant that has flowed out from the passenger compartment-internal radiator 36; an outdoor heat exchanger 43 which receives an inflow of the refrigerant that has passed through the first expansion valve 42; a second expansion valve 44 for decompressing and expanding the refrigerant that has passed through the outdoor heat exchanger 43; the passenger compartment- internal heat sink 35 for causing the refrigerant decompressed and expanded by the second expansion valve 44 to absorb heat; and an accumulator 45 for causing gas / liquid separation of a gas / liquid mixed refrigerant that has passed through the passenger compartment-internal heat sink 35 and drawing only a gas-phase refrigerant into the compressor 41.

[0054] The refrigerant cycle 40 furthermore comprises: an expansion valve (third expansion valve) 46 for decompressing and expanding the refrigerant that has passed through the outdoor heat exchanger 43; and the refrigerant / heating medium heat exchanger 1 in which the refrigerant that has been decompressed and expanded by the third expansion valve 46 flows into the refrigerant flow path 13 through the refrigerant inflow port 11 in order to undergo heat exchange with the liquid heating medium in the heating medium cycle 50, the refrigerant which flows out from the refrigerant / heating medium heat exchanger 1 via the refrigerant outflow port 12 being delivered to the accumulator 45.

[0055] It should be noted that there is no particular limitation to the refrigerant provided that it is a component demonstrating a refrigerant function, and examples of refrigerants which may be used include flon-based refrigerants (HFC-134a and R-1234yf), carbon dioxide (C02) and propane (C3H8) .

[0056] The compressed refrigerant is therefore supplied from the compressor 41 to the passenger compartment-internal radiator 36 and heats the air in the air flow space34 within the air conditioning unit 30, as required, after which the refrigerant is supplied to the outdoor heat exchanger 43 via the first expansion valve 42. After this, the refrigerant which has been decompressed and expanded by the second expansion valve 44 and supplied to the passenger compartment-internal heat sink35 absorbs heat by heat exchange with the air in the airflow space 34, and is then returned to the compressor 41 via the accumulator 45. The refrigerant which has been decompressed and expanded by the third expansion valve 46 and supplied to the refrigerant flow path 13 of the refrigerant / heating medium heat exchanger 1 absorbs heat by heat exchange with the liquid heating medium in the heating medium cycle 50, and is then returned to the compressor 41 via the accumulator 45.

[0057] In the heating medium cycle 50 which internally circulates the liquid heating medium, a first heat-generating element heat sink 52 for absorbing heat of a first heat-generating element 51, and a branch portion DI provided on an outflow side of the first heat-generating element heat sink 52 are connected in that order to the heating medium outflow port 22 of the refrigerant / heating medium heat exchanger 1, and the branch portion DI is connected to the heating medium inflow port 21 and the intermediate heating medium inflow port 25 by way of branch flow paths 53a, 53b.

[0058] Furthermore, the heating medium cycle 50 comprises, at the heating mediumoutflow port 22 of the refr igerant / heating medium heat exchanger 1, the first heat-generating element heat sink 52 for absorbing heat of the first heatgenerating element 51, and the branch portion DI provided on the outflow side of the first heat-generating element heat sink 52, and the branch portion DI is connected to the heating medium inflow port 21 and the intermediate heating medium inflow port 25 of the refr igerant / heat ing medium heat exchanger 1 by way of the branch flow paths 53a, 53b. The heating medium cycle 50 furthermore comprises at least one of: an integrated pump 55 which is provided in a pathway 54 running from the heating medium outflow port 22 to the branch portion DI and delivers the liquid heating medium, and separate flow pumps 55a, 55b respectively provided in the branch flow paths 53a, 53b.Here, the heating medium cycle 50 shown in fig. 12 has a configuration in which the integrated pump 55 for delivering the liquid heating medium is provided in the pathway 54 running from the heating medium outflow port 22 to the branch portion DI, and flow rate regulating valves 56a, 56b for regulating the amount of liquid heating medium flowing through the branch flow paths 53a, 53b are respectively provided in the branch flow paths 53a, 53b.

[0059] In this configuration, the temperature of the liquid heating medium flowing out from the heating medium outflow port 22 can be adjusted by changing a flow rate ratio of the liquid heating medium afforded by the flow rate regulating valves 56a, 56b, and it is therefore possible to provide the first heat-generating element heat sink 52 with the cooling capacity required for the first heatgenerating element 51 by adjusting the flow rate of the liquid heating medium flowing through the branch flow paths 53a, 53b in accordance with the amount of heat generated by the first heat-generating element 51. For example, when there is an increase in the amount of heat generated by the first heat-generating element 51, the flow rate ratio of the flow rate regulating valve 56a provided between the branch portion DI and the heating medium inflow port 21 is increased, while at the same time the flow rate ratio of the flow rate regulating valve 56bprovided between the branch portion DI and the intermediate heating medium inflow port 25 is reduced. By this means, it is possible to increase the ratio of the heating medium flowing from the heating medium inflow port 21 to the heating medium outflow port 22 in the refrigerant / heating medium heat exchanger 1, and the cooling capacity of the liquid heating medium afforded by the refrigerant / heating medium heat exchanger 1 can be increased. The amount of heat absorbed by the first heat-generating element heat sink 52 can then be increased. (Variant example of first embodiment of vehicle air conditioning system)It should be noted that the configuration shown in fig. 12 can also be realized by means of an equivalent heating medium cycle 50. As shown in fig. 13, for example, the integrated pump 55 for delivering the liquid heating medium may be provided in the pathway 54 running from the heating medium outflow port 22 of the refrigerant / heating medium heat exchanger 1 to the branch portion DI, and a three- way flow rate regulating valve 57 may be provided at the branch portion DI, instead of the flow rate regulating valves which were provided in the branch flow paths 53a, 53b.

[0060] By virtue of this confi gurat i on, it is possible to adjust the flow rate proportions of the liquid heating medium flowing through the branch flow paths 53a, 53b by adjusting the three-way flow rate regulating valve 57 provided at the branch portion DI, and it is therefore possible to adjust the proportions of the amount of inflow of the liquid heating medium flowing in from the heating medium inflow port 21 and the amount of inflow of the liquid heating medium flowing in from the intermediate heating medium inflow port 25, thereby enabling adjustment of the cooling capacity required by the first heat-generating element heat sink 52 (enabling adjustment of the amount of heat absorbed from the first heatgenerating element 51).

[0061] (Other variant example of first embodiment of vehicle air conditioning system)Furthermore, as shown in fig. 14, the separate flow pumps 55a, 55b may berespectively provided in the branch flow paths 53a, 53b, without a pump being provided in the pathway 54 running from the heating medium outflow port 22 of the refrigerant / heating medium heat exchanger 1 to the branching portion DI.

[0062] By virtue of this configuration, it is possible to adjust the flow rate of the liquid heating medium flowing through the branch flow paths 53a, 53b by adjusting an amount of outfeed of each of the separate flow pumps 55a, 55b, and it is therefore possible to adjust the cooling capacity required by the first heatgenerating element heat sink 52 (it is possible to adjust the amount of heat absorbed from the first heat-generating element 51).

[0063] (Second embodiment of vehicle air conditioning system)Fig. 15 shows a second embodiment of the vehicle air conditioning system S employing the refrigerant / heating medium heat exchanger 1 (heat exchanger comprising the refrigerant inflow port 11, refrigerant outflow port 12, heating medium inflow port 21, heating medium outflow port 22, and intermediate heating medium inflow port 25) shown in fig. 1 or 10.

[0064] In this example, the vehicle air conditioning system S comprises: a refrigerant cycle 60 for circulating the refrigerant to the passenger compartment-internal heat sink 35 within the air conditioning unit 30; and a heating medium cycle 70 for circulating the liquid heating medium to the passenger compartment- internal radiator 36 within the air conditioning unit 30.

[0065] The refrigerant cycle 60 internally circulates the refrigerant and comprises: a compressor 61 for feeding out the refrigerant; the refrigerant / heating medium heat exchanger 1 in which the refrigerant compressed by the compressor 61 flows into the refrigerant flow path 13 through the refrigerant inflow port 11 in order to undergo heat exchange with the liquid heating medium in the heating medium cycle 70; a first expansion valve 62 which allows the passage of the refrigerantthat has undergone heat exchange with the liquid heating medium in the refrigerant / heating medium heat exchanger 1; an outdoor heat exchanger 63 which receives an inflow of the refrigerant that has passed through the first expansion valve 62; a second expansion valve 64 for decompressing and expanding the refrigerant that has passed through the outdoor heat exchanger 63; the passenger compartment- internal heat sink 35 for causing the refrigerant decompressed and expanded by the second expansion valve 64 to absorb heat; and an accumulator 65 for causing gas / liquid separation of a gas / liquid mixed refrigerant that has passed through the passenger compartment-internal heat sink 35 and drawing only a gas-phase refrigerant into the compressor 61.

[0066] Meanwhile, in the heating medium cycle 70, the passenger compartment- internal radiator 36 for heating the air in the airflow space 34 in the air conditioning unit 30, and a branch portion D2 provided on an outflow side of the passenger compartment- internal radiator 36 are connected in that order to the heating medium outflow port 22 of the refrigerant / heating medium heat exchanger 1, and the branch portion D2 is connected to the heating medium inflow port 21 and the intermediate heating medium inflow port 25 of the refrigerant / heating medium heat exchanger 1 by way of branch flow paths 71a, 71b.

[0067] The heating medium cycle 70 furthermore comprises at least one of: an integrated pump 73 which is provided in a pathway 72 running from the heating medium outflow port 22 to the branch portion D2 and delivers the liquid heating medium, and separate flow pumps 73a, 73b respectively provided in the branch flow paths 71a, 71b.Here, the heating medium cycle 70 shown in fig. 15 has a configuration in which the integrated pump 73 for delivering the liquid heating medium is provided in the pathway 72 running from the heating medium outflow port 22 to the branch portion DI, and flow rate regulating valves 74a, 74b for regulating the amount of liquid heating medium flowing through the branch flow paths 71a, 71b arerespectively provided in the branch flow paths 71a, 71b.

[0068] In this configuration, the temperature of the liquid heating medium flowing out from the heating medium outflow port 22 can be adjusted by changing the flow rate ratio of the liquid heating medium afforded by the respective flow rate regulating valves 74a, 74b, and it is therefore possible to obtain the required heating capacity by adjusting, by means of the flow rate regulating valves 74a, 74b, the flow rate of the liquid heating medium flowing through the branch flow paths 71a, 71b in accordance with the amount of heating required by the passenger compartmentinternal radiator 36. For example, when there is an increase in the amount of heat radiation required by the passenger compartment-internal radiator 36, the flow rate ratio of the flow rate regulating valve 74a provided between the branch portion D2 and the heating medium inflow port 21 is increased, while at the same time the flow rate ratio of the flow rate regulating valve 74b provided between the branch portion D2 and the intermediate heating medium inflow port 25 is reduced. By this means, it is possible to increase the ratio of the heating medium flowing from the heating medium inflow port 21 to the heating medium outflow port 22 in the refrigerant / heating medium heat exchanger 1, and the heating capacity of the liquid heating medium afforded by the refrigerant / heating medium heat exchanger 1 can be increased. The amount of heat radiated by the passenger compartment- internal radiator 36 can then be increased.

[0069] (Variant example of second embodiment of vehicle air conditioning system)It should be noted that the configuration shown in fig. 15 can also be realized by means of an equivalent heating medium cycle 70. As shown in fig. 16, for example, the integrated pump 73 for delivering the liquid heating medium may be provided in the pathway 72 running from the heating medium outflow port 22 to the branch portion D2, and a three-way flow rate regulating valve 75 may be provided at the branch portion D2, instead of the flow rate regulating valves which were provided in the branch flow paths 71a, 71b.

[0070] By virtue of this confi gurat i on, it is possible to adjust the flow rate proportions of the liquid heating medium flowing through the branch flow paths 53a, 53b by adjusting the three-way flow rate regulating valve 57 provided at the branch portion D2, and it is therefore possible to adjust the heating capacity required by the passenger compartment-internal radiator 36 (the amount of heat radiated by the passenger compartment-internal radiator 36).

[0071] (Other variant example of second embodiment of vehicle air conditioning system)In addition, as shown in fig. 17, the separate flow pumps 73a, 73b may be respectively provided in the branch flow paths 71a, 71b, without a pump being provided in the pathway 72 running from the heating medium outflow port 22 to the branch portion D2, and without the three-way flow rate regulating valve being provided at the branch portion D2.

[0072] By virtue of this configuration, it is possible to adjust the flow rate of the liquid heating medium flowing through the branch flow paths 71a, 71b by adjusting an amount of outfeed of each of the separate flow pumps 73a, 73b, and it is therefore possible to adjust the heating capacity required by the passenger compartment- internal radiator 36 (the amount of heat radiated by the passenger compartment- internal radiator 36).

[0073] (Third embodiment of vehicle air conditioning system)Fig. 18 shows a third embodiment of the vehicle air conditioning system S employing the refrigerant / heating medium heat exchanger 1 (heat exchanger comprising the refrigerant inflow port 11, refrigerant outflow port 12, heating medium inflow port 21, heating medium outflow port 22, and intermediate heating medium inflow port 25) shown in fig. 1 or 10.

[0074] In this example, the vehicle air conditioning system S comprises: a refrigerantcycle 80 for circulating the refrigerant to the passenger compartment-internal radiator 36 within the air conditioning unit 30; and a heating medium cycle 90 for circulating the liquid heating medium to the passenger compartment- internal heat sink 35 within the air conditioning unit 30.

[0075] The refrigerant cycle 80 internally circulates the refrigerant and comprises: a compressor 81 for feeding out the refrigerant; the passenger compartmentinternal radiator 36 which is supplied with high-temperature, high-pressure refrigerant compressed by the compressor 81; a first expansion valve 82 which allows the passage of the refrigerant that has flowed out from the passenger compartment- internal radiator 36; an outdoor heat exchanger 83 which receives an inflow of the refrigerant that has passed through the first expansion valve 82; a liquid tank 84 for causing gas / liquid separation of the refrigerant that has passed through the outdoor heat exchanger 83; a second expansion valve 85 for decompressing and expanding a liquid-phase refrigerant from which a gas-phase refrigerant has been separated in the liquid tank 84; and the refrigerant / heating medium heat exchanger 1 for causing heat exchange between the refrigerant that has been decompressed and expanded by the second expansion valve 85 and the liquid heating medium in the heating medium cycle 90.

[0076] Meanwhile, in the heating medium cycle 90, the passenger compartment- internal heat sink 35 for cooling the air flowing through the airflow space 34 in the air conditioning unit 30, and a branch portion D3 provided on an outflow side of the passenger compartment-internal heat sink 35 are connected in that order to the heating medium outflow port 22 of the refrigerant / heating medium heat exchanger 1, and the branch portion D3 is connected to the heating medium inflow port 21 and the intermediate heating medium inflow port 25 of the refrigerant / heating medium heat exchanger 1 by way of branch flow paths 91a, 91b.

[0077] The heating medium cycle 90 furthermore comprises at least one of: an integratedpump 93 which is provided in a pathway 92 running from the heating medium outflow port 22 to the branch portion D3 and delivers the liquid heating medium, and separate flow pumps 93a, 93b respectively provided in the branch flow paths 91a, 91b.Here, the heating medium cycle 90 shown in fig. 18 has a configuration in which the integrated pump 93 for delivering the liquid heating medium is provided in the pathway 92 running from the heating medium outflow port 22 to the branch portion D3, and flow rate regulating valves 94a, 94b for regulating the amount of liquid heating medium flowing through the branch flow paths 91a, 91b are respectively provided in the branch flow paths 91a, 91b.

[0078] In this configuration, the temperature of the liquid heating medium flowing out from the heating medium outflow port 22 can be adjusted by changing the flow rate ratio of the liquid heating medium afforded by the flow rate regulating valves 94a, 94b, and it is therefore possible to obtain the required cooling capacity by adjusting, by means of the flow rate regulating valves 94a, 94b, the flow rate of the liquid heating medium flowing through the branch flow paths 91a, 91b in accordance with the cooling capacity required by the passenger compartmentinternal heat sink 35 (the amount of heat recovered by the passenger compartmentinternal heat sink 35 can be adjusted). For example, when there is an increase in the amount of heat absorption required by the passenger compartment-internal heat sink 35, the flow rate ratio of the flow rate regulating valve 94a provided between the branch portion D3 and the heating medium inflow port 21 is increased, while at the same time the flow rate ratio of the flow rate regulating valve 94b provided between the branch portion D3 and the intermediate heating medium inflow port 25 is reduced. By this means, it is possible to increase the ratio of the heating medium flowing from the heating medium inflow port 21 to the heating medium outflow port 22 in the refrigerant / heating medium heat exchanger 1, and the cooling capacity of the liquid heating medium afforded by the refrigerant / heating medium heat exchanger 1 can be increased. The amount of heatabsorbed by the passenger compartment-internal heat sink 35 can then be increased.

[0079] (Variant example of third embodiment of vehicle air conditioning system)It should be noted that the configuration in fig. 18 can also be realized by means of an equivalent heating medium cycle 90. As shown in fig. 19, for example, the integrated pump 93 for delivering the liquid heating medium may be provided in the pathway 92 running from the heating medium outflow port 22 to the branch portion D3, and a three-way flow rate regulating valve 95 may be provided at the branch portion D3, instead of the flow rate regulating valves which were provided in the branch flow paths 91a, 91b.

[0080] By virtue of this confi gurat i on, it is possible to adjust the flow rate proportions of the liquid heating medium flowing through the branch flow paths 91a, 91b by adjusting the three-way flow rate regulating valve 95 provided at the branch portion D3, and it is therefore possible to adjust the required cooling capacity (the amount of heat absorbed by the passenger compartment-internal heat sink 35) .

[0081] (Other variant example of third embodiment of vehicle air conditioning system)In addition, as shown in fig. 20, the separate flow pumps 93a, 93b may be respectively provided in the branch flow paths 91a, 91b, without a pump being provided in the pathway 92 running from the heating medium outflow port 22 to the branch portion D3, and without the three-way flow rate regulating valve 95 being provided at the branch portion D3.

[0082] By virtue of this configuration, it is possible to adjust the flow rate of the liquid heating medium flowing through the branch flow paths 91a, 91b by adjusting an amount of outfeed of each of the separate flow pumps 93a, 93b, and it is therefore possible to adjust the cooling capacity required by the passenger compartment- internal heat sink 35 (the amount of heat absorbed by the passengercompartment- internal heat sink 35).

[0083] It should be noted that the embodiments above described an example in which a plate heat exchanger formed by stacking the heat transfer plates 5 was used as the refrigerant / heating medium heat exchanger 1, but the refrigerant / heating medium heat exchanger 1 is not limited to this type of heat exchanger, and it is equally possible to use another type of heat exchanger such as a shell-and-tube type or a finned tube type, provided that it enables heat exchange between a refrigerant and a liquid heating medium.[Industrial Applicability]

[0084] The refrigerant / heating medium heat exchanger 1 and vehicle air conditioning system S employing same according to the present invention are suitable for use on board a passenger vehicle.[Key to Symbols]

[0085] I Refrigerant / heating medium heat exchangerII Refrigerant inflow port12 Refrigerant outflow port13 Refrigerant flow path16 Refrigerant circulation layer21 Heating medium inflow port22 Heating medium outflow port23 Heating medium flow path25 Intermediate heating medium inflow port26 Heating medium circulation layer30 Air conditioning unit34 Airflow space35 Passenger compartment-internal heat sink36 Passenger compartment-internal radiator40 Refrigerant cycle46 Third expansion valve50 Heating medium cycle51 First heat-generating element52 First heat-generating element heat sink53a, 53b Branch flow path55, 73, 93 Integrated pump55a, 55b Separate flow pump60 Refrigerant cycle61 Compressor70 Heating medium cycle71a, 71b Branch flow path73a, 73b Separate flow pump80 Refrigerant cycle85 Expansion valve90 Heating medium cycle91a, 91b Branch flow path93a, 93b Separate flow pumpS Vehicle air conditioning systemDI, D2, D3 Branch portion

Claims

[Document Name] CLAIMS

1. Refrigerant / heating medium heat exchanger for performing heat exchange between a refrigerant and a liquid heating medium, the refrigerant / heating medium heat exchanger comprising: a refrigerant inflow port (11) through which the refrigerant flows in, a refrigerant outflow port (12) through which the refrigerant flows out, and a refrigerant flow path (13) for connecting the refrigerant inflow port (11) and the refrigerant outflow port (12) ; a heating medium inflow port (21) enabling the liquid heating medium to flow in, a heating medium outflow port (22) enabling the liquid heating medium to flow out, and a heating medium flow path (23) which connects the heating medium inflow port (21) and the heating medium outflow port (22) and is provided so as to run alongside the refrigerant flow path (13) ; and an intermediate heating medium inflow port (25) which communicates with the heating medium flow path (23), is provided between the heating medium inflow port (21) and the heating medium outflow port (22) as seen along a flow of the liquid heating medium, and enables the liquid heating medium to flow in.

2. Refrigerant / heating medium heat exchanger according to Claim 1, which is constructed by alternately stacking refrigerant circulation layers (16) leading to the refrigerant inflow port (11) and the refrigerant outflow port (12), and heating medium circulation layers (26) leading to the heating medium inflow port (21), the heating medium outflow port (22), and the intermediate heating medium inflow port (25) , characterized in that the refrigerant flow path (13) is formed by the respective refrigerant circulation layers (16), and the heating medium flow path (23) is formed by the respective heating medium circulation layers (26).

3. Vehicle air conditioning system employing the refrigerant / heating medium heat exchanger according to Claim 1 or 2, characterized in that an outflow port of an expansion valve (46) for decompressing and expanding the refrigerant is connected to the refrigerant inflow port (11), the refrigerant which has been decompressed and expanded by the expansion valve (46) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a first heat-generating element heat sink (52) for absorbing heat of a first heatgenerating element (51), a branch portion (DI) provided on an outflow side of the first heat-generating element heat sink (52), and branch flow paths (53a, 53b) which branch at the branch portion (DI), and the vehicle air conditioning system comprises at least one of: an integrated pump (55) which is provided in a pathway (54) running from the heating medium outflow port (22) to the branch portion (DI) and delivers the liquid heating medium, and separate flow pumps (55a, 55b) respectively provided in the branch flow paths (53a, 53b) .

4. Vehicle air conditioning system employing the refrigerant / heating medium heat exchanger according to Claim 1 or 2, characterized in that a compressor (61) is connected to the refrigerant inflow port (11), the refrigerant compressed by the compressor (61) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a passenger compartment-internal radiator (36) disposed in an airflow space (34) of an air conditioning unit (30), a branch portion (D2) provided on an outflow side of the passenger compartment-internal radiator (36), and branch flow paths (71a, 71b) which branch at the branch portion (D2) , andthe vehicle air conditioning system comprises at least one of: an integrated pump (73) which is provided in a pathway (72) running from the heating medium outflow port (22) to the branch portion (D2) and delivers the liquid heating medium, and separate flow pumps (73a, 73b) respectively provided in the branch flow paths (71a, 71b).

5. Vehicle air conditioning system employing the refrigerant / heating medium heat exchanger according to Claim 1 or 2, characterized in that an outflow port of an expansion valve (85) for decompressing and expanding the refrigerant is connected to the refrigerant inflow port (11), the refrigerant which has been decompressed and expanded by the expansion valve (85) is able to circulate in the refrigerant flow path (13), the heating medium outflow port (22) is connected to the heating medium inflow port (21) and the intermediate heating medium inflow port (25) by way of a passenger compartment-internal heat sink (35) disposed in an airflow space (34) of an air conditioning unit (30), a branch portion (D3) provided on an outflow side of the passenger compartment-internal heat sink (35), and branch flow paths (91a, 91b) which branch at the branch portion (D3) , and the vehicle air conditioning system comprises at least one of: an integrated pump (93) which is provided in a pathway (92) running from the heating medium outflow port (22) to the branch portion (D3) and delivers the liquid heating medium, and separate flow pumps (93a, 93b) respectively provided in the branch flow paths (91a, 91b).

Images