An evaporator is provided with a refrigerant pipe, a cold storage case which has inner fins mounted therein, and air-side fins. The evaporator is characterized in that the cold storage case is provided with: a filling opening for filling the cold storage case with a cold storage material; a first flow passage connecting to the filling opening and extending in the same direction as the direction of inflow of the cold storage material; and a second flow passage connecting to the first flow passage and extending in the direction intersecting the first flow passage.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2013/059979 filed on Apr. 1, 2013 and published in Japanese as WO 2013/151017 A1 on Oct. 10, 2013. This application is based on and claims the benefit of priority from Japanese Patent Application No. 2012-083969 filed on Apr. 2, 2012. The entire disclosures of all the above applications are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an evaporator which has cold storage cases in which a cold storage material is filled and inside of which inner fins are arranged sandwiched between refrigerant tubes.

BACKGROUND ART

In recent years, the number of vehicles with “idling stop” systems which turn the engines off when stopping for a stop traffic light or otherwise idling so as to improve the fuel economy has been increasing. In such an “idling stop” vehicle, sometimes the compressor of the air-conditioning system stops while the vehicle is at a stop (while the engine is stopped) and therefore the comfort of the air-conditioning is decreased. Further, to maintain the air-conditioned feeling, sometimes the engine ends up being restarted even while the vehicle is stopped. Therefore, in order to maintain the air-conditioned feeling even while the engine is stopped, a cold storage function evaporator which gives a cold storage function to the evaporator of a refrigeration cycle system has been proposed in the past. According to this cold storage function evaporator, it is possible to store the coldness during vehicle operation and use this cold air while the vehicle is stopped.

Such a cold storage function evaporator stores coldness in the cold storage material by solidification of the cold storage material in the cold storage cases during operation of the air-conditioner compressor. On the other hand, during idling stop, conversely the solid cold storage material melts while discharging cold air into sucked air so as to keep down the changes in temperature of the sucked air and maintain the air-conditioned feeling until the cold storage material completely melts. In the case of sandwiching the cold storage cases which are filled with the cold storage material between refrigerant tubes, time is taken for heat conduction from the outside wall surfaces of the cold storage cases to the cold storage material at the centers of the insides of the cases, so inner fins are often disposed in the insides of the cold storage cases for the purpose of shortening the heat conduction time.

When arranging inner fins inside the cold storage cases for the purpose of shortening the heat conduction time, the cold storage and cold discharge performance is improved, but as shown in PLT 1, the problem arose that the end parts of the inner fins, the peak parts of the corrugated shapes, etc. adhered to the inside surfaces of the cold storage cases so at the time of filling the cold storage material, the flow path of the flow of cold storage material could not be secured, so much time was taken for filling.

CITATIONS LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

The present invention, in consideration of the above problems, provides an evaporator which has cold storage cases in which inner fins are arranged and which is designed to enable the cold storage cases to be filled with a cold storage material in a short time.

Solution to Problem

To solve the above problems, the aspect of the invention of claim1provides an evaporator provided with refrigerant tubes (10), cold storage cases (2) which mount inner fins (3) inside them, and air side fins (20), wherein each cold storage case (2) is provided with a filling port (5) for filling a cold storage material, a first flow path (V) which is communicated with the filling port (5) and extends in the same direction as the direction of flow of the cold storage material, and a second flow path (H) which is communicated with the first flow path (V) and extends in a direction which intersects the first flow path (V). Due to this, at the time of filling, the flow path for the cold storage material which is filled from the filling port (5) to flow in the same direction as the direction of inflow down to the bottom part of the cold storage case is secured and the cold storage material from the filling port can be filled inside the cold storage case2in a short time.

To solve the above problems, the aspect of the invention of claim9provides an evaporator equipped with a cold storage function which is provided with refrigerant tubes (10), cold storage cases (2) which mount inner fins (3) inside them, and air side fins (20), wherein each cold storage case (2) is provided with a filling port (5) for filling a cold storage material and is provided with a vertical direction flow path (V) through which the cold storage material which was filled from the filling port (5) at the time of filling flows in the vertical direction straight down to a bottom part of the cold storage case and a horizontal direction flow path (H) through which the cold storage material moves in the horizontal direction. In this case as well, advantageous effects similar to the aspect of the invention of claim1are obtained.

Note, the above reference notations are examples which show correspondence with specific examples which are described in the later explained embodiments.

DESCRIPTION OF EMBODIMENTS

Below, referring to the drawings, embodiments of the present invention will be explained. Parts of the same configuration in the different embodiments will be assigned the same reference notations and explanations thereof will be omitted.

In the refrigeration cycle system of a vehicular air-conditioning system, there are a compressor, condenser, pressure reducer, and evaporator40. The evaporator40has, as one example, a first heat exchanger48and a second heat exchanger49arranged in two layers. Further, the second heat exchanger49is arranged at an upstream side of the flow of air, while the first heat exchanger48is arranged at a downstream side of the flow of air. The present embodiment is not limited to such a two-layer arrangement. It may also be a single-layer structure and can be applied broadly to evaporators equipped with cold storage functions for vehicular use.

The refrigerant passage members comprise first to fourth headers41to44positioned forming sets and a plurality of refrigerant tubes10which connect the headers41to44. The first header41and the second header42form a set and are arranged in parallel separated from each other by a predetermined distance. The third header43and the fourth header44also form a set and are arranged in parallel separated from each other by a predetermined distance. Between the first header41and the second header42, a plurality of refrigerant tubes10are arranged at equal intervals. These refrigerant tubes10are communicated with the insides of the corresponding headers41and42at their end parts. These first header41, second header42, and the plurality of refrigerant tube10arranged between them form the first heat exchanger48.

Between the third header43and the fourth header44, a plurality of refrigerant tubes10are arranged at equal intervals. The refrigerant tubes10are communicated with the insides of the corresponding headers43and44at their end parts. These third header43, fourth header44, and the plurality of refrigerant tubes10which are arranged between them form the second heat exchanger49.

The refrigerant tubes10are tubes which are formed in a flat shape and which form refrigerant passages inside them. The refrigerant tubes10are formed by pressing, punching, or other sheet working. The refrigerant tubes10can also be obtained by extrusion. A plurality of refrigerant passages therefore extend along the longitudinal directions (Z-axial direction ofFIG. 1) of the refrigerant tubes10and open at the two ends of the refrigerant tubes10. A plurality of refrigerant tubes10are arranged in rows. At each row, a plurality of refrigerant tubes10are arranged so that their flat surfaces face each other.

At the evaporator40, air side fins20are arranged at each air passage which is defined between two adjoining refrigerant tubes10. The air side fins20may be also arranged between the refrigerant tubes10and the cold storage members1. The air side fins20are joined to the two adjoining refrigerant tubes10by a brazing material. The air side fins20are formed by bending thin aluminum or other metal sheets into corrugated shapes by about 3 to 4 mm pitches. The direction of air flow of the air side fins20is the Y-axial direction inFIG. 1.

The evaporator40is an evaporator with a cold storage function which has a plurality of cold storage members1. Each cold storage members1is formed from a cold storage case2which is formed into a flat tubular shape by aluminum or another metal and houses a cold storage material (paraffin-based etc.) inside. The cold storage member1has broad flat surfaces at the two surfaces which are respectively arranged in parallel with refrigerant tubes10. At the cold storage case2at the sides joined with the refrigerant tubes10, projecting parts4such as shown inFIG. 2Bstick out. These are formed in slanted shapes so as to facilitate the discharge of condensed water or ice which is formed at the time of cold storage. At the top part of the cold storage case2, a filling port5through which the cold storage material is made to flow to the inside of the cold storage case2is connected.

Such an evaporator equipped with a cold storage function stores cold by the cold storage material inside the cold storage cases2solidifying during operation of the air-conditioner compressor. During “idling stop”, conversely the solid cold storage material is made to melt to cool the air which passes through the air passages. Due to this, up the cold storage material completely melts, temperature changes in the sucked air can be suppressed, and the air-conditioned feeling can be maintained.

In the case of the present embodiment where cold storage cases2which are filled with the cold storage material are sandwiched between the refrigerant tubes10, the distance of heat movement from the surfaces of the cold storage cases to the cold storage material becomes close to ½ of the clearance between refrigerant tubes, so time is taken for cold storage. Therefore, in the present embodiment, for the purpose of shortening the distance of heat movement, inner fins3which are bent in a corrugated shape are attached inside the cold storage cases2. When arranging inner fins3inside the cold storage cases2, the cold storage and cold discharge performance is improved, but the inner fins3are brazed to the inside surfaces of the cold storage cases2. In the regions in the cold storage cases2where the inner fins3are arranged, the inner fins3are used to define and form a plurality of narrow flow paths. Sub flow paths are formed between adjoining peak parts31and peak parts31. For this reason, at the time of filling the cold storage material, the flow paths for flow of cold storage material cannot be secured, so time was taken for filling.

To solve this problem, there is provided a cold storage case2which mounts inner fins3at the inside. The cold storage case2is provided with a filling port5for filling a cold storage material, a first flow path V which communicates with the filling port5and extends straight in the same direction as the direction of flow of the cold storage material, and a second flow path H which communicates with the first flow path V and extends in a direction which intersects the first flow path V. The first flow path V is formed in a region in the cold storage case2where no inner fins3are arranged. The flow area of the first flow path V is larger than the flow area of the sub flow paths, and the flow resistance of the first flow path V is set smaller than the flow resistance of the sub flow paths of the inner fins3. The second flow path H communicates with the end part of the first flow path V at the opposite side from the filling port5side and is formed to extend in a direction which intersects the first flow path V. In the case ofFIG. 3andFIG. 4, the second flow path H is the flow path which extends along the ridge direction of the peak parts31of the inner fins at the bottom part of the cold storage case2. In the case ofFIG. 5, the flow path which is formed at the bottom part of the cold storage case2corresponds to the second flow path H, but the second flow path H may also be other various flow paths. In the case ofFIGS. 6A and 6B, the flow path which is formed running through the through holes7corresponds to the second flow path H. In the case ofFIG. 4, the cold storage case2has a flat cross-sectional shape vertical to the longitudinal direction, and the direction of the first flow path V is the longitudinal direction of the cold storage case2. The first flow path V communicates with the filling port5and extends straight in the same direction as the direction of flow of the cold storage material, so it is possible to make the cold storage material which flows in from the filling port5flow into the first flow path V with priority. After this, the cold storage material which flows into the first flow path V flows into the second flow path H which is formed at the cold storage case2. As a result, it is possible to efficiently fill the cold storage material. In particular, when filling it, the first flow path V extends in a direction communicating with the filling port5in a straight line so that the cold storage material which is filled from the filling port5flows straight down to the bottom part of the cold storage case, the first flow path V is larger in flow area than the sub flow paths, and the first flow path V is smaller in flow resistance than the sub flow paths, so the cold storage material flows to the first flow path V with priority. When filling the cold storage material, the invention can be applied even if not a straight line in the strict sense so long as a range in which no flow resistance particularly occurs in the shape of the flow path.

The inner fins3may be arranged as shown inFIG. 3so that the direction of advance of the corrugations becomes the width direction of the cold storage case2(in the figure, Y-axial direction) or may be arranged as shown inFIG. 5so that the direction of advance of the corrugations becomes the longitudinal direction of the cold storage case2(in the figure, Z-axial direction).

As shown inFIGS. 6A, 6B, and 7, when the ridge direction of the peak parts31of the inner fins extends in the width direction of the cold storage case2, the flat plate parts which form the peak parts31of the inner fins3are provided with a plurality of through holes7. The cold storage material which flows into the first flow path V can be made to pass through these through holes7.

The second embodiment is an embodiment in which the first flow path V is a vertical direction flow path where the cold storage material which was filled from the filling port flows in the vertical direction straight down to the bottom part of the cold storage case, and where the second flow path H is a horizontal direction flow path where the cold storage material moves in the horizontal direction. The cold storage case2is provided with a filling port5for filling the cold storage material and is provided with, at the inside, a vertical direction flow path V through which the cold storage material which was filled from the filling port5at the time of filling flows in the vertical direction straight down to the bottom part of the cold storage case, and a horizontal direction flow path H where the cold storage material moves in the horizontal direction. Normally, the longitudinal direction of the cold storage case2, as seen inFIG. 2B, is the Z-axial direction. Therefore, at the time of filling, as shown inFIG. 3, the case is turned 90 degrees, then the cold storage material is made to face the vertical direction and is filled so as to drop down by gravity. Of course, it is also possible, like inFIG. 4of the later explained third embodiment, to fill it while the case is standing in the longitudinal direction. In the second embodiment, as shown inFIG. 3, at the time of filling, that is, after turning the case 90 degrees inFIG. 2B, a vertical direction flow path V where the cold storage material which was filled from the filling port5flows in the vertical direction straight down to the bottom part of the cold storage case is provided. The vertical direction flow path V serves as a buffer to accumulate the cold storage material once then allow it to flow along the peak shapes of the inner fins3in the horizontal direction. Due to this, compared with the past, it is possible to efficiently finish the filling in about half of the filling time.

The horizontal direction flow path H is formed by the valley parts32between the adjoining peak parts31and peak parts31of the inner fins3which are formed by being bent to a corrugated shape so that the filled cold storage material flows in the horizontal direction. By arranging the line which connects the vertices of the peak parts31of the inner fins3(below, referred to as the “crest direction”) parallel to the longitudinal direction (Z-axial direction) of the cold storage case2, at the time of filling, the cold storage material flows along the peak shapes of the inner fins3. In the second embodiment, the direction of filling the cold storage material of the filling port5is set to the air flow direction (Y-axial direction) of the air side fins. In this case, it is possible to shorten the distance between the headers41,43and42,44(Z-axial direction). The direction of flow of the filling port5(inflow port) of the cold storage case2and the crest direction of the inner fins3are at right angles. Note, preferably a certain clearance is provided between the end parts of the inner fins3and the filling port5.

As explained above, by making the direction of the filling port5and the vertical direction flow path V which is connected with this and the crest direction of the inner fins3form right angles, the cold storage material from the filling port can be filled inside the cold storage case2in a short time. Note that, the crest direction of the inner fins3is not necessarily limited to right angles and may also be slanted.

In the third embodiment, as shown inFIG. 4, vertical direction flow paths V are provided along the Z-axial direction so as to enable filling vertically in the longitudinal direction. At the time of filling, the cold storage material which is filled from the filling port5passes through the vertical direction flow path V and flows in the vertical direction straight until the bottom part of the cold storage case. The horizontal direction flow path H (Y-axial direction) is formed by the valleys32between adjoining peak shapes31and peak shapes31of the inner fins3which are bent in a corrugated shape whereby the filled cold storage material flows in the horizontal direction. In the present embodiment, similar effects as the second embodiment are obtained.

Referring toFIG. 5, a fourth embodiment will be explained. In the fourth embodiment, as shown inFIG. 5, a space is formed between the end parts of the inner fins3(inFIG. 5, bottom end parts) and the bottom part of the cold storage case2, and the cold storage material is made able to flow along the bottom part of the cold storage case2in the horizontal direction by providing at least single flow path holding projections6,60at the bottom part of the cold storage case2. Here, the “bottom part of the cold storage case” is the side surface of the case which becomes the bottom in the vertical direction at the time of filling. The flow path holding projections6,60do not necessarily have to be two. The inner fins3are fastened to the cold storage case2by brazing or other fastening means, so one is also possible or a suitable number may be set. If the number of peaks of the inner fins3is large and the fins are long in the longitudinal direction, a plurality of flow path holding projections may be provided. The width of the flow path holding projections in the Z-axial direction ofFIG. 5(longitudinal side direction) is greater than a size of the inner fin pitch fp of the mounted fins. Further, if placing the flow path holding projections6at the bottom part of the cold storage case2the furthest from the filling port5, the filled cold storage material is not obstructed from flowing in the horizontal direction.

As seen in the cross-sections A-A and B-B ofFIG. 5, the flow path holding projections6,60are set at just single sides in the width direction so as not to close the horizontal direction flow path H. In the case of the fourth embodiment, even when the crest direction of the inner fins3is parallel to the vertical direction flow path V, a horizontal direction flow path H can be secured. Of course, as shown inFIG. 3, even the case where the vertical direction flow path V and the crest direction of the inner fins3are perpendicular is included in the fourth embodiment.

Referring toFIGS. 6A and 6BandFIGS. 7 to 10, fifth and sixth embodiments will be explained. In the case of the fifth embodiment, the crest direction of the inner fins3is parallel to the vertical direction flow path V. In this case, since blocked in the crest direction of the inner fins3, the horizontal direction flow path H cannot be secured. In such a case, as seen inFIG. 7, the flat plate parts33of the inner fins are provided with pluralities of through holes7so that, as shown inFIG. 6B, the filled cold storage material can be moved from the vertical direction flow path V to the horizontal direction flow path H. In the present embodiment, similar effects as the second embodiment are obtained.

The through holes7are not limited to circles or squares. As one example, ovals or rectangles such as inFIG. 8may be mentioned. The minimum values of size in the case of holes in this case are “b” and “c”. When providing the inner fins3with holes enabling cold storage material to pass, the fear arises of a detrimental effect on the heat conduction performance. However, if the minimum values “b” and “c” of the size of the through holes are half of the inner fin pitch fp or less, there is no detrimental effect on the heat conduction performance. The “inner fin pitch fp” means the distance between adjoining peak parts31and peak parts31of the inner fins which are bent in a corrugated shape. As shown inFIG. 9, if the flat plate parts33of the inner fins are set in parallel, the distance between the flat plate parts33of the repeating units may be made the inner fin pitch fp.

The reason why there is no detrimental effect at all on the heat conduction performance if half or less of the inner fin pitch fp will be explained below using FIG.10. The flow of heat conduction at the time of filling is from the cold storage cases2through the inner fins3to the cold storage material. In the cold storage material, the center parts O1of the valley parts32of the inner fins3(on centerlines of valley parts) become the locations where heat is finally conducted from the flat plate parts33of the left and right inner fins ofFIG. 10. If the heat conduction speed is α, if comparing the time T of heat conduction over the heat conduction distance (¼)fp from the point O2to the point O1and time t of heat conduction over the heat conduction distance b/2 through the through holes7from the point O4to the point O3and T≥t, there is no detrimental effect on the heat conduction performance at all. The reason is that when conducting heat from point O2to point O1, heat is already finishing being conducted from the point O4 to the point O3. If T=(¼×fp)/α and t=(b/2)/α, the result becomes b≤(½)fp. Therefore, it is learned that if the minimum values “b” and “c” of the size of the through holes7are half of the inner fin pitch fp or less, there is no detrimental effect on the heat conduction performance.

By making the size of the through holes7(½)fp or less, the through holes have no detrimental effect on the filling time, the through holes7enable a flow path for the flow of filling of the cold storage material to be secured, and the filling time of the cold storage material can be shortened.

In the case of the seventh embodiment, as seen inFIG. 11B, the flat plate parts33of the inner fins are provided with pluralities of through holes7zigzag at the flat plate parts of the different rows. If doing this, in the same way as the fifth embodiment, the filled cold storage material can move from the vertical direction flow path V to the horizontal direction flow path H. For the size of the through holes7, the same formula stands as in the sixth embodiment. The rest is similar to the fifth embodiment in both configuration and advantageous effects.

In the case of the eighth embodiment, as seen inFIG. 12AandFIG. 12B(cross-sectional view along the line C-C), the flat plate parts33of the inner fins3which are arranged inside the cold storage cases2are formed with louvers8which are cut and raised from the flat plate parts33. The louvers8have a louver pitch Lp (seeFIG. 12B) of ½fp or less (Lp≤½fp). Note, the “louver pitch Lp” is the distance between centers of adjoining louvers in the same plane as the flat plate parts33. In the case of the eighth embodiment, the louver pitch Lp of the louvers8corresponds to the minimum value of the through holes7in the sixth embodiment. The rest is similar to the other embodiments in both configuration and advantageous effects.

REFERENCE SIGNS LIST

2cold storage case