Heat exchanger with a cold storage unit

Abstract

Heat exchanger (40) with a cold storage unit comprising: a first and a second extension box (41, 42); a plurality of cooling tubes (45) arranged at intervals between the first and the second extension box (41, 42) such that a coolant flows through the cooling tubes (45) at least from one of the boxes according to the first and the second extension box (41, 42) to the other extension box (41, 42), wherein the cooling tubes (45) comprise a first cooling tube, a second cooling tube, a third cooling tube, a fourth cooling tube and a fifth cooling tube, wherein the cooling tubes (45) are arranged in the order first cooling tube, second cooling tube, third cooling tube, fourth cooling tube and fifth cooling tube; a first cold storage container (47; 247; 347; 547; 647; 747e, 747f; 847;947), which is arranged in a first receiving space formed between the second and third cooling tubes and which is directly attached to the second and third cooling tubes on both sides of the first cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947); a cold storage material (50) which is inserted into an inner surface of the first cold storage container (47, 347); a space forming a first air duct, which is formed between the first cooling tube and the second cooling tube; a space forming a second air duct, which is formed between the third cooling tube and the fourth cooling tube; a space forming a third air duct, which is formed between the fourth cooling tube and the fifth cooling tube;a plurality of fins (46) each provided in the spaces forming the first to third air ducts, such that the fins (46) provided in the spaces forming the second and third air ducts are directly attached to the fourth cooling tube on both sides of the fourth cooling tube; a heat exchange section (47b; 247b; 347b; 547b; 647b) provided in the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) and projecting into the inside of the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947), wherein the receiving spaces located between adjacent cooling tubes (45) and on both sides of the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) are formed as air channels through which air passes for heat exchange with the coolant flowing through the first to fifth cooling tubes (45).

Description

The present application relates to a heat exchanger having a cold storage used in a refrigeration period or operation.A refrigeration period or operation is used for an air conditioner or air conditioner. There have been made many proposals according to which a cooling operation is carried out although it may be a limited operation even if an operation of the refrigerating operation is stopped. For example, in the case of an air conditioner for a vehicle, the refrigeration cycle or operation is performed by an engine for driving the vehicle. Therefore, when the engine operation is temporarily stopped while the vehicle is being stopped, the operation of the refrigerating operation is also stopped in the same manner. According to one of the ideas, a cold storage heat exchanger in which a cold storage device is attached to the heat exchanger is used in the refrigeration operation to provide a cooling operation even at a temporary stop of the vehicle (i.e., during a temporary engine stop).For example, the following conventional techniques (patent documents) are known in the present field: (1) Japanese Patent Publication JP 2004-184 071 A (2) Japanese Patent Publication JP 2002-274 165 A (3) Japanese Patent Publication (PCT) JP 2006-503 253 A (4) Japanese Patent Publication JP 2002-225 536 A (5) Japanese Patent Publication JP 2001-107 035 AAccording to the disclosures of the above-mentioned Patent Specifications (1) and (2), cooling tubes are formed on one side of a cold storage device, and fins for heat exchange with air are formed on the other side thereof. According to the above-mentioned construction, the cold storage device is cooled from one side thereof. Therefore, there is a consideration that the cold storage device is not sufficiently cooled. On the other hand, air is directly brought into heat exchange with the cold storage device on the other side thereof. When air having a high temperature comes into contact with the cold storage device, the stored cold energy is discharged very quickly. As is apparent from the above, in the conventional devices, it is difficult to efficiently cool the cold storage device and stably radiate the stored cold energy.According to the disclosures of the above-mentioned Patent Specifications (3) and (4), a cold storage device is provided at a part of a heat exchanger. The stored cold energy travels toward fins via cooling tubes along the longitudinal direction of the cooling tubes. It is therefore difficult to achieve a high cooling capacity. Further, since cold storage material and a fin are disposed between adjacent cooling tubes, high productivity cannot be achieved.In the above-mentioned Patent Document (5), cold storage members are provided instead of the fins for heat exchange. According to such a construction, however, high productivity cannot be obtained either, because a plurality of cold storage cells are disposed between the cooling tubes.U.S. Pat. No. 7,156,156 B2 describes a heat exchanger which comprises circulating channels for circulating heat transfer fluid, which are arranged between an inlet and an outlet. Herein, cavities for receiving fluid for storing heat are disposed adjacent to the circulation channels. A heat exchange surface may be swept by the air flow so that the heat storage fluid may exchange heat with the air flow in the case of stopping the circulation of the heat transfer fluid.DE 10 2004 035 818 A1 describes an evaporator with latent storage.The present invention has been developed in view of the above-mentioned problems.It is an object of the present invention to provide a heat exchanger having a cold accumulator capable of efficiently storing cold energy and capable of stably radiating the stored cold energy.Another object of the present invention is to provide a heat exchanger with a cold storage, in which high productivity can be realized.This object is achieved by the heat exchanger having the features mentioned in claim 1.The present invention comprises one of the following features or a combination of the following features:According to a feature of the invention, a heat exchanger with a cold accumulator has first and second header tanks (41, 42) and a plurality of cooling tubes (45) spaced between the first and second header tanks (41, 42) so that the coolant flows through the cooling tubes (45) from at least one of the first and second header tanks (41, 42) toward the other header tank (41, 42).The heat exchanger further includes a cold storage container (47, 247, 347, 447, 547, 647, 747e, 747f, 847, 947) which is disposed in a storage space which is formed between adjacent cooling tubes (45) and which is thermally connected to the cooling tubes (45), further includes a cold storage material (50) which is inserted into an inside of the cold storage container, and a heat exchange portion (47b, 247b, 347b, 447b, 547b, 647b, 647b) which is provided in the cold storage container and which protrudes into the inside of the cold storage container.In the above-mentioned heat exchanger, the accommodation spaces formed between adjacent cooling tubes (45) and on both sides of the cold storage container are formed as air passages through which air flows for heat exchange with the coolant flowing through the cooling tubes (45).According to the above-mentioned heat exchanger, the cold storage material can be efficiently cooled by the cooling tubes disposed on both sides of the cold storage container, so that an effective cold energy storage operation can be realized. The cooling pipe is provided between the cold storage container and the air duct, so that the cold energy is stably radiated from the cold storage material toward the air duct.Further, the cold storage container includes the heat exchange portion provided in the cold storage container and protruding into the inside of the cold storage container. As a result, both cold energy storage and cold energy radiating operation can be effectively carried out. Moreover, since the cold storage container is connected to the cooling tubes, not only high mechanical strength but also high heat transfer can be obtained.According to another feature of the invention, a plurality of fins (46) are provided in the air passage accommodation spaces, so that heat exchange between the cold storage material and the air flowing through the air passages is facilitated.According to another feature of the invention, the cooling tubes (45) are arranged at equal intervals, and a width (T) of the cold storage container is substantially equal to that of the air passage passage. According to such a construction, the air passage passage and the cold storage container can be exchanged with each other, so that the flexibility in selection of a number as well as selection of a position of the cold storage containers in the heat exchanger can be increased.According to still another feature of the invention, an occupancy ratio of the cold storage container occupying the accommodation spaces formed between the cooling tubes has a value between 10% and 50% of the total space of the accommodation spaces formed between the cooling tubes. According to such a feature, the cold energy storage quality as well as the cold energy radiation quality can be maintained appropriately.According to still another feature of the invention, the cold storage container is joined to the cooling tubes by brazing material. According to such a feature, heat transfer between the cooling tubes and the cold storage containers can be increased by the brazing material. In addition, the same brazing material for connecting the fins to the cooling tubes as well as the same brazing furnace may be used together to connect the cold storage containers to the cooling tubes.According to still another feature of the invention, the cold storage container is composed of a pair of main wall portions (47a, 447a) and a plurality of partitioning portions (47b, 447b), each of the partitioning walls or partitions extending from one of the wall portions toward the other wall portion. A container of this type is known as a multi-channel tube which is produced by an extrusion operation.According to still another feature of the invention, the heat exchanger is provided with an inner fin (247b, 347b) provided in the cold storage container. According to this feature, the heat exchanging portion can be provided by the inner fin that can be easily manufactured.According to still another feature of the invention, the heat exchanging portion is formed by protrusions (47b, 447b, 547b, 647b), each of which protrudes from one of the cold storage container wall portions (47a, 447a, 547a, 647a) toward the other cold storage container wall portion (47a, 447a, 547a, 647a). According to this feature, the cold storage container can be manufactured with a smaller number of parts.According to still another feature of the invention, a plurality of cold storage containers are arranged at equal intervals so that temperature distribution is avoided.According to still another feature of the invention, a plurality of cold storage containers are uniformly disposed on right and left sides of the heat exchanger with respect to the center thereof, so that a temperature difference between the right and left sides of the heat exchanger can be avoided.According to still another feature of the invention, a plurality of cold storage containers are arranged symmetrically with respect to the center of the heat exchanger. According to such a feature, the temperature distribution for the right and left sides of the heat exchanger can be made symmetrical.According to still another feature of the invention, a heat exchange portion formed between the cooling tubes, the cold storage container, and the air passage passages are in communication with a single air flow passage formed in an air conditioning apparatus on a downstream side of the heat exchanger. According to such a feature, the air flowing through the single air flow passage can be cooled by the heat exchange portion of the evaporator.According to still another feature of the invention, the heat exchange portion formed by the cooling tubes, the cold storage container, and the air passage passages are divided into two heat exchange portions, and each of the heat exchange portions is in flow communication with the respective air flow passages formed on a downstream side of the heat exchanger in the case of air conditioning. According to such a feature, air flowing through the different air flow passages can be separately cooled by the respective heat exchange regions.According to still another feature of the invention, the heat exchanger includes two-layer first and second heat exchange portions (48, 49), a cold storage container (47, 747e), and two cooling tubes (45) disposed on both sides of the cold storage container and forming a first cold storage unit disposed in the first heat exchange portion (48), and another cold storage container (47, 747f) and other two cooling tubes (45) disposed on both sides of the other cold storage container and forming a second cold storage unit disposed in the second heat exchange portion (49).The first and second cold storage units are aligned with each other in a direction of the air flow passing through the heat exchanger, and the first and second cold storage units are separated from each other to form a space therebetween which constitutes a heat insulator.According to such a feature, even in a case where a temperature difference occurs between the first and second cold storage units, a decrease in the cold energy storage quality as well as a decrease in the cold energy radiation quality can be suppressed for the two cold storage units.According to still another feature of the invention, the heat exchanger includes first and second heat exchange portions (48, 49) formed of two layers, a cold storage container (847, 947), and two cooling tubes (45) disposed on both sides of the cold storage container, and form a first cold storage unit disposed in the first heat exchange portion (48), and includes another cold storage container (847, 947) and other two cooling tubes (45) disposed on both sides of the other cold storage container and form a second cold storage unit disposed in the second heat exchange portion (49).The first and second cold storage units are aligned with each other in a direction of the air flow passing through the heat exchanger, and the first and second cold storage units are connected to each other via a partition wall ( 847 g) or a restricted portion ( 947 h) serving as a heat insulator.According to such a feature, even in a case where a temperature difference occurs between the first and second cold storage units, a decrease in the cold energy storage quality as well as a decrease in the cold energy radiation quality for the two cold storage units can be suppressed in the same manner.The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, there are shown: FIG. 1 is a schematic block diagram showing a refrigeration cycle according to a first embodiment of the present invention; FIG. 2 is a plan view showing a heat exchanger according to the first embodiment; FIG. 3A is a side view illustrating heat exchangers according to the first embodiment; FIG. 3B is a schematic perspective view of the heat exchanger with a coolant flow in the heat exchanger; FIG. 4 is an enlarged fragmentary view showing a transverse cross section taken along a line IV--IV of FIG. 2; FIG. 5 is an enlarged fragmentary view illustrating a longitudinal cross section taken along a line V-V of FIG. 3A ; FIG. 6 is a graph showing a relationship between an occupancy ratio RM and a capacity VM of a cold storage material; FIG. 7 is a graph illustrating a relationship between the occupancy ratio RM and a heat transfer area AM of the cold storage material; FIG. 8 is a graph showing a relationship between the occupancy ratio RM and a rib area AF; FIG. 9 is a graph illustrating a relationship between the occupancy ratio RM and a cold energy radiating capacity WM of the cold storage material; FIG. 10 is a graph illustrating a relationship between the occupancy ratio RM and a cooling capacity WR of the coolant; FIG. 11 is an enlarged fragmentary view showing a transverse cross section of a heat exchanger according to a second embodiment of the present invention; FIG. 12 is an enlarged fragmentary view showing a longitudinal cross section of the heat exchanger according to the second embodiment of the present invention; FIG. 13 is an enlarged fragmentary view illustrating a transverse cross section of a heat exchanger according to a third embodiment of the present invention; FIG. 14 is an enlarged fragmentary view illustrating a longitudinal cross section of the heat exchanger according to the third embodiment of the present invention; FIG. 15 is an enlarged fragmentary view showing a transverse cross section of a heat exchanger according to a fourth embodiment of the present invention; FIG. 16 is an enlarged fragmentary view showing a transverse cross section of a heat exchanger according to a fifth embodiment of the present invention; FIG. 17 is an enlarged fragmentary view showing a transverse cross section of a cold storage container for a heat exchanger according to a sixth embodiment of the present invention; FIG. 18 is an enlarged fragmentary view illustrating a transverse cross section of a heat exchanger according to a seventh embodiment of the present invention; FIG. 19 is an enlarged fragmentary view showing a transverse cross section of a heat exchanger according to an eighth embodiment of the present invention; FIG. 20 is an enlarged fragmentary view showing a transverse cross section of a heat exchanger according to a ninth embodiment of the present invention; FIG. 21A is a schematic block diagram showing a discharge type refrigerating cycle according to a tenth embodiment of the present invention; FIG. 21B is a schematic perspective view of the heat exchanger showing the flow of refrigerant in the heat exchanger; FIG. 22 is a schematic cross-sectional view illustrating an air conditioning apparatus according to an eleventh embodiment of the present invention; FIG. 23 is a plan view of a heat exchanger according to the eleventh embodiment; FIG. 24 is a plan view of a heat exchanger according to a twelfth embodiment; FIG. 25 is a plan view of a heat exchanger according to a thirteenth embodiment; and FIG. 26 is a plan view of a heat exchanger according to a fourteenth embodiment.(First Embodiment)FIG. 1 is a schematic block diagram illustrating a refrigeration cycle 1 according to a first embodiment of the present invention. The refrigeration cycle 1 is used for an air conditioner (air conditioner) for a vehicle. The refrigeration cycle 1 includes a compressor 10, a heat radiator 20, a pressure release device 30, and a heat exchanger (evaporator) 40 which are connected in a closed cycle by cooling pipes so that a refrigerant can circulate in the closed cycle. The compressor 10 is driven by a drive source 2 made up of an internal combustion engine for driving the vehicle. Therefore, when the drive source 2 is stopped, the operation of the compressor 10 is also stopped. The compressor 10 draws the refrigerant from the evaporator 40, compresses the same, and discharges the compressed refrigerant to the heat radiator 20. The heat radiation device 20 cools the high temperature coolant. The heat radiation device 20 is also referred to as a condenser. The pressure relief or decompression device 30 decompresses the refrigerant that has been cooled by the condenser 20. The pressure relief device or decompression device 30 may be comprised of a fixed orifice, a temperature-dependent type expansion valve, or an ejector. The evaporator 40 evaporates the refrigerant 40 decompressed by the decompressing device 30 to cool the air flowing through the evaporator 40, so that the cooled air is supplied into a passenger compartment of the vehicle. The refrigeration cycle may further include an internal heat exchanger for performing heat exchange between the high-pressure side refrigerant and the low-pressure side refrigerant, and also include a tank such as a receiver or an accumulator for storing an excessive amount of the refrigerant. The vehicle drive source 2 may be an internal combustion engine or an electric motor.FIG. 2 is a plan view illustrating the evaporator 40 made of a cold storage type heat exchanger according to the first embodiment. FIG. 3A is a side view illustrating the heat exchanger of FIG. 2. FIG. 3B is a schematic perspective view of the heat exchanger showing the flow of refrigerant in the heat exchanger. FIG. 4 is an enlarged fragmentary view showing a transverse cross section taken along a line IV--IV of FIG. 2. FIG. 5 is an enlarged fragmentary view showing a longitudinal cross section taken along a line V-V of FIG. 3.In FIGS. 2, 3A, and 3B, the evaporator 40 includes a plurality of refrigerant flow paths formed by passage parts made of metal such as aluminum, for example. The coolant flow paths are formed by pairs of header tanks 41, 42, 43 and 44 and a plurality of cooling tubes 45 connecting the header tanks of each pair. The coolant flows are indicated by arrows in FIG. 3B.In FIGS. 2, 3A and 3B, first and second header tanks 41 and 42 form a first pair of tanks, each of the header tanks 41 and 42 being arranged at a predetermined interval and parallel to each other. In the same manner, third and third and fourth header boxes 43 and 44 are arranged at a predetermined interval and parallel to each other. A plurality of cooling tubes 45 are arranged between the first and second header boxes 41 and 42 at equal intervals. Each end of the cooling tubes 45 is in flow communication with the inner sides of the header tanks 41 and 42. a first heat exchange portion 48 is formed by the first and second header tanks 41 and 42 and the plurality of cooling tubes 45 interposed therebetween.In the same manner, a plurality of cooling tubes 45 are arranged between the third and fourth header boxes 43 and 44 at equal intervals. Each end of the cooling tubes 45 is in fluid communication with the inner sides of the header tanks 43 and 44. a second heat exchange portion 49 is formed by the third and fourth header tanks 43 and 44 and the plurality of cooling tubes 45 interposed therebetween. As stated above, the heat exchanger 40 is composed of two-layered first and second heat exchange portions 48 and 49, the second heat exchange portion 49 is positioned on an upstream side of the air flow, and the first heat exchange portion 48 is positioned on a downstream side thereof.A joint (joint) provided at an inlet portion for the coolant is provided at an end of the first header box 41. The inside of the first header box 41 is divided into two (first and second) header box portions 41a and 41b by a partition wall (not shown) provided at a longitudinal intermediate portion of the first header box 41. The plurality of cooling tubes 45 are divided into two (first and second) tube groups 48A and 48B. The coolant flows into the first header box portion 41 aof the first header box 41, and then the coolant is distributed from the first header box portion 41 ato the plurality of cooling tubes of the first tube group 48A. The coolant flows through the cooling tubes 45 of the first tube group 48A and then flows to the second header box 42, and the coolant is cooled in the second header box 42 and is distributed toward the plurality of cooling tubes 45 of the second tube group 48B. The coolant then flows through the plurality of cooling tubes 45 of the second tube group 48B and flows into the second header box portion 41 bof the first header box 41. as stated above, a U-shaped flow path for the coolant is formed in the first heat exchange portion 48.A connection point formed as an outlet portion for the coolant is provided at the one end of the third header box 43. The inside of the third header box 43 is likewise divided into two (first and second) header box portions 43a and 43b by another partition wall (not shown) provided at a longitudinal intermediate portion of the third header box 43. The plurality of cooling tubes 45 are also divided into two (first and second) tube groups 49A and 49B. The first header box portion 43 aof the third header box 43 is provided adjacent to the second header box portion 41 bof the first header box 41 so that the first header box portion 43 aof the third header box 43 and the second header box portion 41 bof the first header box 41 are in fluid communication with each other as indicated by a dashed line in FIG. 3B.The coolant flows from the second header box portion 41 bof the first header box 41 into the first header box portion 43 aof the third header box 43, and then the coolant is distributed from the first header box portion 43 ato the plurality of cooling tubes of the first tube group 49A. The coolant flows through the cooling tubes 45 of the first tube group 49A and then flows into the fourth header box 44, and the refrigerant is collected in the fourth header box 44 and is distributed to the multiple cooling tubes 45 of the second tube group 49B. The coolant flows through the plurality of cooling tubes 45 of the second tube group 49B and then flows into the second header box portion 43 bof the third header box 43. The refrigerant flowing out of the outlet portion from the second header box portion 43 bof the third header box 43 reaches the compressor 10.In FIGS. 4 and 5, the cooling pipe 45 is formed of a multi-channel pipe having a plurality of refrigerant flow channels. The cooling pipe 45 is also referred to as a flat pipe 45. The tube having the multiple channels may also be manufactured by an extrusion process. A plurality of coolant flow paths or passages extend in a longitudinal direction of the cooling pipe 45 and are open to both ends of the cooling pipe 45. A plurality of the cooling tubes 45 are arranged in a line extending parallel to the longitudinal direction of the header boxes. The plurality of cooling tubes 45 are arranged in the line so that each of the main surfaces thereof are opposed to each other. A plurality of the accommodation spaces are formed between the adjacent cooling tubes 45. A plurality of cold storage containers 47 are disposed in some of the storage spaces, while air passage passages (through which air flows and the air is cooled via heat exchange with the coolant flowing through the cooling tubes) are formed in the remaining storage spaces, which will be explained later.The evaporator 40 includes a plurality of ribs 46 disposed in the air passages to increase the area of contact with the air to be supplied to the passenger compartment of the vehicle. The fin 46 is formed of a corrugated fin 46. The fin 46 is thermally connected to the cooling tubes 45. The fin 46 is attached to the cooling tubes 45 by a bonding material that ensures high heat transfer. The connecting material may be made of a brazing material. The rib 46 may be made of a thin metal plate formed in a wave shape such as aluminum. A plurality of cooling slots (Louvers) are formed on or in the rib 46.The evaporator 40 further includes a plurality of cold storage containers 47 made of a metal such as aluminum. The cold storage container 47 is formed as a multi-compartment flat tube, and many compartments are formed to extend longitudinally. A longitudinal end of the cold storage container 47 is flattened outward in the thickness direction thereof so that the end thereof is closed. Both longitudinal ends of the container 47 are closed so that the cold storage material 50 is inserted and retained therein in a sealing manner. Each of the cold storage containers 47 includes a pair of main outer side surfaces each of which is in surface-to-surface contact with the main surface of the cooling tubes 45.The cold storage containers 47 are disposed in the accommodation spaces formed between the adjacent cooling tubes 45 and are thermally connected thereto. The cold storage containers 47 are attached to the cooling tubes 45 by a joining material having high heat transfer capability. A brazing material or a resin material such as a bonding material may be used as the bonding material. The cold storage containers 47 are soldered to the cooling tubes 45. A large amount of brazing material is disposed between the cold storage containers 47 and the cooling tubes 45 so as to be joined to each other over a large surface area. The brazing material may be plated on either side or both sides of the cold storage containers 47 and the cooling tubes 45. As a result, high heat transfer can be realized between the cold storage containers 47 and the cooling tubes 45.In FIGS. 4 and 5, a thickness "T" of the cold storage container 47 is substantially equal to that of the air passage passage passage (i.e., the accommodation space). Therefore, the thickness "T" of the cold storage container 47 is also substantially equal to that of the fin 46, and the cold storage containers 47 and the fins 46 can perform heat exchange with each other. Thus, there is higher flexibility in design of a pattern for the plurality of cold storage containers 47 and the plurality of fins 46. the thickness "T" of the cold storage container 47 is larger than a thickness of the cooling pipe 45. A length "L" of the cold storage container 47 is almost equal to that of the corrugated fin 46, and therefore almost the entirety of the accommodation space in the longitudinal direction between the adjacent cooling tubes 45 is occupied by the cold storage container 47. Any gap of the accommodation space in the longitudinal direction between the cold storage container 47 and the header box 41, 42, 43, or 44 may be preferably occupied by a small piece of the corrugated fins 46 or by filler material such as resin.The cold storage container 47 includes a pair of main wall portions 47 athat form main outer side surfaces, and includes a plurality of partitioning portions 47 bthat extend from one wall portion 47 ato the other wall portion 47 ato connect both wall portions 47 ato each other. A plurality of small spaces for the cold storage material 50 are formed in the cold storage container 47, the small spaces extending in the longitudinal direction of the cold storage container 47. The plurality of small spaces are disposed in the cold storage container in a direction of the air flow passing through the evaporator 40. Each of the small spaces is in fluid communication with each other at both longitudinal ends of the cold storage container 47.In FIG. 2, the plurality of cooling tubes 45 are arranged at a constant interval. There are formed many spaces (i.e., the accommodation spaces) between adjacent cooling tubes 45, respectively. The plurality of fins 46 and the plurality of cold storage containers 47 are respectively disposed in the plurality of accommodation spaces in accordance with a predetermined order. The receiving spaces in which the ribs 46 are arranged form air ducts. The remaining storage spaces are the spaces for the cold storage containers 47. Between 10% and 50% of all the storage spaces between the cooling tubes 45 are used as spaces for the cold storage containers 47. The cold storage containers 47 are arranged at equal intervals above the evaporator 40. Each of the cooling tubes 45 disposed on both sides of the cold storage container 47 respectively defines the air passage passage together with each of the opposite cooling tubes 45 through which the air passes to perform heat exchange with the coolant passing through the cooling tubes 45. In other words, the two cooling tubes 45 are disposed between two fins 46, and a cold storage container 47 is disposed between two cooling tubes 45.A cold storage container 47 and two adjacent cooling tubes 45 constitute a cold storage unit. In the evaporator 40, a plurality of the cold storage units having the same construction are arranged at equal intervals. Further, the plurality of cold storage units are arranged at equal intervals in a bilateral direction. In addition, the plurality of cold storage units are arranged symmetrically.A plurality of the first cold storage units disposed in the first heat exchange portion 48 and a plurality of the second cold storage units disposed in the second heat exchange portion 49 are arranged in a laminated manner and are aligned with each other in the direction of the air flow. The cold storage containers 47 of the first cold storage units and the cold storage containers 47 of the second cold storage units are separated from each other, and spaces are provided therebetween, which serve as heat insulating means.A pattern of the cooling tubes 45, the fins 46, and the cold storage containers 47 will be explained below when the evaporator is viewed from the innermost end thereof (for example, from the leftmost end in FIG. 2 ). A side plate is disposed at the leftmost end of the evaporator 40 in the form of a reinforcing member. The rib 46 is disposed between the reinforcing member (the side plate) and the cooling pipe 45 which is the first pipe from the leftmost end. The ribs 46 are disposed on both sides of the first cooling pipe 45. The cold storage container 47 is disposed between the second and third cooling tubes 45. The fin 46 is disposed between the third and fourth cooling tubes 45. The fin 46 is also disposed between the fourth and fifth cooling tubes 45. The cold storage container 47 is disposed between the fifth and sixth cooling tubes 45. The fin 46 is disposed between the sixth and seventh cooling tubes 45. The above-mentioned pattern repeats from the leftmost end toward the rightmost end of the evaporator 40.According to the construction of Fig. 2, the fins 46 are provided at both side ends of the evaporator 40. The cold storage containers 47 are not disposed at both side ends. Further, the fins 46 are disposed on both sides of the leftmost and rightmost cooling tubes 45. The cold storage containers 47 are not disposed on both sides of the leftmost and rightmost cooling tubes 45. The cold storage containers 47 are disposed only between predetermined adjacent cooling tubes 45. Also, the fins 46 are not disposed between such cooling tubes 45 between which the cold storage container 47 is disposed. The fins 46 are disposed on both sides of the cold storage unit, that is, the fins 46 are disposed on the outer sides of the cooling tubes 45 positioned on both sides of the cold storage container 47. According to the above-mentioned arrangement, the cooling tubes 45 and the fins 46 are arranged symmetrically with respect to the cold storage container 47. This symmetrical arrangement for the cold storage containers 47, the cooling tubes 45 and the fins 46 is formed throughout the evaporator 40.FIGS. 6 to 10 are graphs each showing relationships between an occupancy ratio of the cold storage containers 47 and various characteristics of the evaporator 40. According to the construction of FIG. 2, the cold storage containers 47 occupy one third of the total accommodation spaces between the cooling tubes, and the remaining two thirds of the accommodation spaces between the cooling tubes are occupied by the fins 46, that is, the air passages. Therefore, the occupying ratio of the cold storage container 47 is 33%. The occupying ratio is selected so as to realize a high cold energy radiation characteristic. The present inventors have studied the quality of the evaporator 40 in terms of the occupying ratio in many ways. According to the study of the inventors, high quality of the evaporator can be obtained in a case where the occupancy ratio is set within a predetermined range.For example, as illustrated in FIG. 6, a capacity VM of the cold storage material 50 may be increased as the occupancy ratio RM is made larger. As shown in FIG. 7, a heat transfer area AM of the cold storage material 50 may be increased as the occupancy ratio AM is made larger. Further, as shown in FIG. 8, a rib area AF of the rib 46 is relatively decreased as the occupancy ratio RM is made larger.Taking the above-mentioned characteristics into consideration, a cooling quality by the cold storage material 50, that is, a cold energy radiating capacity WM, is obtained as a characteristic curve having a maximum value with respect to the occupancy ratio RM. FIG. 9 is a graph showing a relationship between the occupancy ratio RM and the cold energy radiating capacity WM. As shown in FIG. 9, a high cold energy radiating capacity WMcan be achieved when the occupancy ratio RMis set to a value within a range that is greater than 10% but less than 60%. The occupying ratio of about 30% is very preferable for obtaining the highest cold energy radiating capacity WM. As shown in FIG. 10, the cooling capacity WR of the coolant decreases as the occupancy ratio RM is increased. In view of the possible cooling capacity WR required for an air conditioner, a higher cooling capacity WR is better. From this viewpoint, an occupancy ratio RM may be preferable when it is less than 50%. According to the present embodiment, the occupancy ratio is set to 33% in view of matching between the cold energy radiating capacity WM by the cold storage material and the cooling capacity WR of the coolant.An operation of the present embodiment will now be explained. When an instruction for an air conditioning operation is issued, for example, an instruction for a cooling operation by a vehicle passenger, a compressor 10 is driven by the drive source 2. The compressor 10 draws the refrigerant from the evaporator 40, compresses the same, and discharges the compressed refrigerant. The refrigerant discharged from the compressor 10 is radiated (radicalized) at the heat radiation device 20. The refrigerant from the heat radiator 20 is decompressed by the decompressor 30, and is supplied to the evaporator 40. The refrigerant is evaporated at the evaporator 40, thereby not only cooling the cold storage container 47 but also cooling the air flowing through the evaporator 40 via the fins 46.When the vehicle is temporarily stopped, the operation of the drive source 2 is also stopped to reduce the power consumption. Then, the operation of the compressor 10 is stopped. Thereafter, the refrigerant in the evaporator 40 gradually loses its cooling capacity. During this process, the cold storage material 50 gradually dissipates cold energy to thereby cool the air. In this operation, the heat of the air is transferred to the cold storage material 50 via the fins 46, the cooling tubes 45, and the cold storage containers 47. As a result, the air can be continuously cooled by the cold storage material 50 even after the refrigeration cycle 1 is temporarily stopped. Then, when the vehicle starts moving again, the drive source 2 drives the compressor 10 again, so that the refrigeration cycle 1 cools the cold storage material 50 and the refrigeration energy is stored.According to the present embodiment, the cooling tubes 45 and the fins 46 (the air passages or air passages) are arranged symmetrically with respect to the cold storage container 47. As a result, the cold storage material 50 is effectively cooled by the pair of wall portions 47 aof the cold storage container 47. The cold storage container 47 stores the cold energy from both sides in the same manner. In addition, the cold storage container 47 evenly radiates the stored cold energy from both sides.The cold storage container 47 is not in direct contact with the fins 46. the cold storage container 47 is thermally connected to the fins 46 at least via the cooling tubes 45. Accordingly, even in a case where high temperature air temporarily flows through the air passages or air passages, excessive radiation of the cold energy from the cold storage material 50 can be prevented.The occupying ratio of the cold storage container 47 with respect to the storage spaces of the evaporator 40 is 1 / 3. Therefore, while the cooling capacity of the refrigerant is not largely deteriorated, a high cold energy radiating capacity WM can be achieved by the cold storage material. The plurality of partition walls 47 boperating as heat exchange portions increase the contact area between the cold storage container 47 and the cold storage material 50, so that effective heat exchange between the cold storage container 47 and the cold storage material 50 can be realized. The cold storage container 47 is joined to the cooling tubes 45 via the brazing material, thereby achieving high heat transfer and high productivity.According to the present embodiment, the evaporator 40 provides a heat exchange surface or surface area. The heat exchange surface area is disposed in a single air flow channel defined in an air conditioning flow channel (formed in an air conditioning device). The plurality of cold storage containers 47 are arranged at equal intervals in the evaporator 40. As a result, the cold storage containers 47 are arranged in the evaporator 40 at equal intervals. Specifically, the plurality of cold storage containers 47 are uniformly arranged distributed in the bilateral direction in which the plurality of cooling tubes 45 are arranged in a line. The plurality of cold storage containers 47 are arranged symmetrically with respect to a center line of the evaporator 40 in the bilateral direction in which the cooling tubes 45 are arranged in a line. According to such an arrangement of the cold storage containers 47, temporary distribution in a right-left direction (the bilateral direction) in the air conditioning operation can be suppressed.(Second Embodiment)FIGS. 11 and 12 are partial enlarged views illustrating a heat exchanger (evaporator) according to a second embodiment of the present invention, wherein FIG. 11 is a transverse cross-sectional view and FIG. 12 is a longitudinal cross-sectional view. FIG. 11 corresponds to a part of the cross-sectional view taken along line IV-IV of FIG. 2, FIG. 12 corresponds to a part of the cross-sectional view taken along line V-V of FIG. 3, the same reference numerals of the first embodiment are used for those portions in the embodiment that are the same as the first embodiment.A cold storage container 247 is formed in the shape of a flat tube having a rectangular cross section. The cold storage container 247 has a pair of main wall portions 247 aand a pair of side wall portions 247 c. A corrugated inner fin 247 bconstitutes a heat exchange portion and is disposed inside the cold storage container 247, and many upper portions and lower portions of the inner fin 247 bare alternately disposed in the direction of the air flow. Each of the upper and lower portions of the inner fin 247 bextends in a longitudinal direction of the cold storage container 247, and these many upper and lower portions are soldered to the main wall portions 247 a. According to such a construction, the contact area between the cold storage container 247 and the cold storage material 50 can be increased by the inner fin 247 b.(Third Embodiment)Figs. 13 and 14 are partial enlarged views showing a heat exchanger (evaporator) according to a third embodiment of the present invention, wherein Fig. 13 is a transverse cross-sectional view and Fig. 14 is a longitudinal cross-sectional view. FIG. 13 corresponds to a part of the cross-sectional view taken along the line IV-IV of FIG. 2, FIG. 14 corresponds to a part of the cross-sectional view taken along the line V-V of FIG. 3, like reference numerals of the first embodiment are used for portions in this embodiment that are the same as the first embodiment.A cold storage container 347 is formed as a flat tube having a rectangular cross section in the same manner as the cold storage container 247 of the second embodiment (FIGS. 11 and 12 ). The cold storage container 347 includes a pair of main wall portions 347 aand a pair of side wall portions 347 c. A corrugated inner fin 347 bforming a heat exchange portion is disposed inside the cold storage container 347, and a plurality of upper and lower portions of the inner fin 347 bare alternately disposed in the longitudinal direction of the cold storage container 347. Each of the upper and lower portions of the inner fin 347 bextends in the direction of the air flow, and these many upper and lower portions are brazed to the main wall portions 347 a. According to such a construction, the contact area between the cold storage container 347 and the cold storage material 50 can also be increased by the inner fin 347 b.(Fourth Embodiment)FIG. 15 is an enlarged partial view illustrating a heat exchanger (evaporator) according to a fourth embodiment of the present invention, in which FIG. 15 is a transverse cross-sectional view corresponding to a part of the cross-sectional view taken along line IV-IV of FIG. 2. Like reference numerals of the first embodiment are used for those portions of this embodiment which are the same as those of the first embodiment.The cold storage container 447 has a width W in the direction of the air flow, the width W being equal to an additional value of the width of the first heat exchange portion 48 and a width of the second heat exchange portion 49. Since the cold storage container 447 has the width W covering both widths for the two-layer heat exchange portions 48 and 49 of the evaporator 40, it is possible to increase the capacity VM of the cold storage material 50.The cold storage container 447 has a similar construction to that of the cold storage container 47 of the first embodiment (FIG. 4 ). The cold storage container 447 includes a pair of main wall portions 447 athat form the main outer side surfaces and includes many partitioning portions 447 bthat form heat exchange portions, each of the partitioning portions 447 bextends from one wall portion 447 ato another wall portion 447 ato thereby define a plurality of small spaces arranged in a layering direction of the two-layered heat exchange portions 48 and 49 (that is, in the direction of the air flow). Two cooling tubes 45 are disposed on an outer side surface of the cold storage container 447. Other two cooling tubes 45 are similarly disposed on the other outer side surface of the cold storage container 447. In other words, the cold storage container 447 includes a plurality of cooling tubes 45 on each of the outer side surfaces. As shown in FIG. 15, the cold storage container 447 includes a plurality of small spaces (including units) arranged in the direction of the width W. Each of the units included has a length L equal to the length L shown in the first embodiment (FIG. 2 ). The cold storage container 447 having the plurality of contained units is disposed between adjacent cooling tubes 45.(Fifth Embodiment)FIG. 16 is an enlarged fragmentary view illustrating a heat exchanger (evaporator) according to a fifth embodiment of the present invention, FIG. 16 being a transverse sectional view corresponding to a part of the cross sectional view taken along the line IV-IV of FIG. 2. Like reference numerals of the first embodiment are used for those portions in this embodiment which are the same as those of the first embodiment.A cold storage container 547 includes a pair of main wall portions 547a and a plurality of protrusions 547b each of which protrudes from one wall portion 547a toward the other wall portion 547a, the protrusions 547b constituting heat exchange portions. The cold storage container 547 has a plurality of small spaces which are in flow communication with each other to form a continuous inner space. An opening 547 cis formed at one of the side wall portions through which the cold storage material 50 is introduced into the inner space of the cold storage container 547. The opening 547 cis formed at the side wall portion placed on either the upstream or the downstream side of the evaporator 40 in the air flow. A sealing member 547d made of thermosetting resin such as epoxy resin is stuffed into the opening 547c.When the evaporator 40 is manufactured, parts for the heat storage containers 547, the cooling tubes 45, the fins 46, and other parts are first prepared. Then, these parts are temporarily assembled. The temporarily assembled evaporator (half-manufactured evaporator) is then placed in a brazing furnace to perform a brazing process. The cold storage containers 547, the cooling tubes 45 and the fins 46 are brazed together firmly.The cold storage material 50 is then introduced into the cold storage containers 547 through the openings 547 c. The sealing members 547d are then inserted or plugged into the openings 547c. According to the present invention, the cold storage containers 547 can be easily assembled to the evaporator 40 during the manufacturing process. The fabrication process may also be used in other embodiments of the present invention.(Sixth Embodiment)FIG. 17 is an enlarged partial view illustrating a cold storage container for a heat exchanger (evaporator) according to a sixth embodiment of the present invention, and FIG. 17 is a transverse sectional view. A cold storage container 647 is formed of a thin metal plate bent into a flat tube shape. One end of the metal plate is crimped around the other end. The cold storage container 647 includes a pair of main wall portions 647 aextending in a longitudinal direction (a direction perpendicular to the sheet plane of FIG. 17 ). Each of the longitudinal ends of the cold storage container 647 is flattened in its thickness direction (in the right-left direction in FIG. 17 ) so that the end thereof is closed.A plurality of recesses 647 bare formed on the wall portions 647 a. The recess 647 bis formed by a convex portion that protrudes from one wall portion toward the other wall portion. The recesses form heat exchange portions. Each of the recesses 647b formed on one wall portion 647a faces the corresponding recesses 647b formed on the other wall portion 647a, and the respective opposite upper portions of the recesses are connected to each other. The plurality of recesses increases the contacting area between the cold storage material 50 and the cold storage container 647. The cold storage container 647 of the present embodiment can be used as a cold storage container for other embodiments of the present invention.(Seventh Embodiment)FIG. 18 is a partial enlarged view illustrating a heat exchanger (part of an evaporator) according to a seventh embodiment of the present invention, wherein FIG. 18 is a transverse sectional view corresponding to a part of the cross sectional view taken along the line IV-IV of FIG. 2. The same reference numerals as in the first embodiment are used for those portions in the present embodiment which are the same as in the first embodiment.A first cold storage unit (having a cold storage container 747 eand having two cooling tubes 45 on both sides of the cold storage container 747 e) is provided in the first heat exchange portion 48. A second cold storage unit (having a cold storage container 747 fand having two cooling tubes 45 on both sides of the cold storage container 747 f) is similarly provided in the same heat exchange portion 49. The first and second cold storage units are separated from each other so that a space (functioning as a heat insulator) is formed between the first and second cold storage units.According to the above-mentioned construction, the first and second cold storage units are thermally separated from each other, so that heat transfer between the cold storage containers 747 eand 747 fis suppressed. As a result, the temperature of the cold storage container 747 ecan be controlled to a different value from that of the cold storage container 747 f. In addition, heat transfer between the cold storage material 50 in the cold storage container 747 eand the cold storage material 50 in the cold storage container 747 fis suppressed. Movement of the cold storage material 50 in the container 747 eor 747 fcan also be suppressed. A heat insulating member may be disposed between the cold storage containers 747 eand 747 f. In the present embodiment shown in FIG. 18, inner fins are disposed in the respective cold storage containers 747 eand 747 f. The cold storage containers illustrated with the above-explained first to sixth embodiments can also be applied to the present seventh embodiment.The cooling tubes 45 of the first heat exchange portion 48 are disposed on an upstream side with respect to the coolant flow. The cooling tubes 45 of the second heat exchange portion 49 are therefore disposed on a downstream side with respect to the coolant flow. The coolant in the cooling tubes 45 of the second heat exchange section 49 can enter an overheated gas state even when the coolant in the cooling tubes 45 of the first heat exchange section 48 is in a two-phase gas-liquid state. As a result, the temperature of the cold storage material 50 of the second heat exchange portion 49 may rise higher than a melting point even when the temperature of the cold storage material 50 of the first heat exchange portion 48 is lower than the melting point. As stated above, there may be a case where a temperature difference occurs between the first and second heat exchange portions 48 and 49 resulting from the coolant flow.The first heat exchange portion 48 is disposed on the downstream side with respect to the air flow. The second heat exchange portion 49 is therefore disposed on the upstream side with respect to the air flow. As a result, a temperature difference between the first and second heat exchange portions 48 and 49 may also occur depending on the air flow. In such a case that the temperature difference occurs in a single cold storage container, there is a possibility that both the cold energy storage efficiency and the cold energy radiation efficiency can be lowered.However, according to the present embodiment, the heat insulating portion is provided between the cold storage containers 747 eand 747 f. Therefore, even if the temperature difference occurs between the first and second heat exchange portions 48 and 49, it is possible to suppress a decrease in both the cold energy storage efficiency and the cold energy radiation efficiency. For example, the temperature of only one of the cold storage containers (for example, the cold storage container 747 e) is maintained below the melting point, and then the cold energy can be stored only in such a cold storage container 747 e.(Eighth Embodiment)FIG. 19 is a partial enlarged view showing a heat exchanger (part of an evaporator) according to an eighth embodiment of the present invention, wherein FIG. 19 is a transverse sectional view corresponding to a part of the cross sectional view taken along the line IV-IV of FIG. 2. The same reference numerals as in the first embodiment are used for those portions in the present embodiment which are the same as in the first embodiment.A cold storage container 847 has a similar construction to the above-explained construction of the seventh embodiment (FIG. 18 ). The cold storage container 847 is made up of a single container, and a partition wall 847 gis provided to partition an inner space into two spaces for the first and second heat exchange portions 48 and 49. The partition wall 847 gis also used as a heat insulating portion between the cold storage materials 50 in the respective inside spaces of the cold storage container 847.A first cold storage unit (consisting of a portion of the cold storage container 847 for the first heat exchange portion 48 and the cooling tubes 45) and a second cold storage unit (consisting of a portion of the cold storage container 847 for the second heat exchange portion 49 and the cooling tubes 45) are connected to each other by means of the partition wall 847g which also serves as a heat insulator.According to the above-mentioned construction, heat transfer between the cold storage materials 50 in the respective interiors of the cold storage container 847 can be suppressed. Movement of the cold storage material 50 in the cold storage container 847 can also be suppressed. The cold storage containers of the first to sixth embodiments may also be used in the present embodiment in place of the cold storage container 847. Even if a temperature difference would occur between the first and second heat exchange portions 48 and 49, since the heat insulating portion (the partition wall 847g) is provided inside the cold storage container 847, it is possible to suppress a decrease in both the cold energy storage efficiency and the cold energy radiation efficiency.(Ninth Embodiment)FIG. 20 is a partial enlarged view illustrating a heat exchanger (part of an evaporator) according to a ninth embodiment of the present invention, in which FIG. 20 is a transverse sectional view corresponding to a part of the cross sectional view taken along the line IV-IV of FIG. 2. The same reference numerals as those in the first embodiment are also used for those parts in the present embodiment which are the same as those in the first embodiment.A cold storage container 947 has a similar construction to the above-explained construction of the eighth embodiment (FIG. 19 ). The cold storage container 947 is made of a single container, and a restricted portion 947 his provided to thereby provide two inside spaces for the cold storage material 50 for the first and second heat exchange portions 48 and 49. The restricted or narrowed portion 947 his also used as a heat insulating portion between the cold storage materials 50 in the respective inside spaces of the cold storage container 947.A first cold storage unit (consisting of a portion of the cold storage container 947 for the first heat exchange portion 48 and the cooling tubes 45) and a second cold storage unit (consisting of a portion of the cold storage container 947 for the second heat exchange portion 49 and the cooling tubes 45) are connected to each other via the restricted portion 947h acting as a heat insulator.According to the above-mentioned construction, heat transfer between the cold storage materials 50 in the respective inside spaces of the cold storage container 947 can be suppressed. Movement of the cold storage material 50 in the container 947 can also be suppressed. The cold storage containers of the first to sixth embodiments may also be used in the present embodiment in place of the cold storage container 947. Even if a temperature difference occurs between the first and second heat exchange portions 48 and 49, it is possible to suppress a decrease in both the cold energy storage efficiency and the cold energy radiation efficiency because the heat insulating portion (the restricted portion 947 h) is provided in the inside of the cold storage container 947.The restricted or narrowed portion 947 hmay be formed by press working by forming groove-shaped recess portions opposing each other at an intermediate portion of the cold storage container 947. The movement of the cold storage material 50 between two inside spaces can be completely prevented by the restricted portion 947 h. Alternatively, the restricted portion 947 hmay be formed such that a small amount of the cold storage material 50 may move through the restricted portion 947 h, thereby improving workability when the cold storage material 50 is introduced into the inside spaces.(Tenth Embodiment)FIG. 21A is a schematic block diagram showing an ejector type refrigeration cycle 1001 according to a tenth embodiment of the present invention. FIG. 21B is a schematic perspective view of a heat exchanger 1040 applied to the tenth embodiment, in which the coolant flow in the heat exchanger is indicated by arrows. Like reference numerals according to the above embodiments are used for those portions in the present embodiment which are the same as the portions of the above embodiments.Refrigeration cycle or working circuit 1001 includes an ejector 60 having a high pressure inlet port, a low pressure inlet port, and a mixed refrigerant outlet port. The high-pressure refrigerant is supplied to the ejector 60 via the high-pressure inlet port, so that the ejector 60 discharges a high-pressure refrigerant from a nozzle. The refrigerant is sucked into the ejector through the low-pressure inlet port when the high-pressure refrigerant is ejected from the nozzle. The coolant discharged from the nozzle and the coolant sucked through the low-pressure inlet port are mixed with each other in the ejector 60. The mixed refrigerant is then slowed and pressurized. The mixed refrigerant is then discharged from the mixed refrigerant discharge port of the ejector 60.An evaporator 1040 has a similar construction to the evaporator 40 of the first embodiment as shown in FIG. 21B. In the first embodiment, the evaporator 40 includes a communication portion for fluidly connecting the second header portion 41 bof the first header box 41 to the first header portion 43 aof the third header box 43 so that the refrigerant flows from the first header box 41 to the third header box 43. However, the evaporator 1040 of the present embodiment does not have such a communication portion. Instead, a refrigerant outlet port is formed at the second header portion 41 bof the first header box 41, and a refrigerant inlet port is formed at the first header portion 43 aof the third header box 43, so that each exchanging portion according to the first and second heat exchanging portions 1048 and 1049 functions as an independent evaporator. The first heat exchange portion 1048 is disposed on a downstream side with respect to an air flow passing through the evaporator 1040. The second heat exchange portion 1049 is disposed on an upstream side with respect to the air flow.A refrigeration working circuit 1008 includes a bifurcated refrigerant path on a downstream side of the heat radiation device 20, and a first decompressing device 31 is provided in a cooling path connected to the high-pressure inlet port of the ejector 60. A second decompressing device 32 is provided in another cooling path (branch path) connected to an inlet port of the first heat exchanging portion 1048. An outlet port of the first heat exchange portion 1048 is connected to the low-pressure inlet port of the ejector 60. The mixed refrigerant outlet port of the ejector 60 is connected to an inlet port of the second heat exchange portion 1049. The outlet port of the second heat exchange portion 1049 is connected to the compressor 10. According to the above-mentioned construction, the first heat exchanging portion 1048 is connected to a suction side of the ejector 60, but the second heat exchanging portion 1049 is connected to a discharge side of the ejector 60. As a result, the temperature of the first heat exchange portion 1048 becomes lower than that of the second heat exchange portion 1049. As set forth above, a temperature difference occurs between the first and second heat exchange portions 1048 and 1049.The cold storage containers of the above-explained embodiments can be applied to the evaporator 1040. The cold storage containers of the seventh to ninth embodiments may be preferably applied to the evaporator 1040. With such an arrangement (the evaporator 1040 including the cold storage containers of the seventh to ninth embodiments), it becomes possible to maintain the temperature difference between the first and second heat exchange portions 1048 and 1049.(Eleventh Embodiment)FIG. 22 is a schematic cross-sectional view showing an air conditioner 70 according to an eleventh embodiment of the present invention. Like reference numerals according to the above embodiments are used for those portions in the present embodiment which are the same portions as those in the above embodiments.The air conditioner 70 is composed of an air conditioner which is applied to a vehicle to supply conditioned air or conditioned air having different temperatures into two rooms, one room for a driver and another room for a passenger. The air conditioner 70 includes a blower unit 71, a temperature adjustment unit 72 (that is, an air conditioner), and air passage units 76 aand 76 b. The evaporator 40 is provided inside the temperature adjustment unit 72 and covers an entire air flow passage thereof. A central plate 73 is provided in the temperature adjusting unit 72 to thereby form two air flow passages. The central plate 73 extends from a downstream side of the evaporator 40 to the air passage units 76 aand 76 b. In each of the air flow passages divided by the central plate 73, an air mixing door 75a (75b) and a heater core 74a (74b) are provided.A flow amount of hot air passing through the heater core 74 a( 74 b) and a flow amount of cold air passing across the heater core 74 a( 74 b) are adjusted by the air mixing door 75 a( 75 b), so that the temperature of the mixed air flowing into the air passage units 76 a( 76 b) can be controlled to a desired temperature. The air mix doors 75a and 75b are controlled independently of each other. On the downstream sides of the respective air flow passages, the air passage unit 76a for the driver and the air passage unit 76b for the passenger are provided. Each of the air duct units 76a and 76b includes many openings connected to a defroster duct, a front duct, a foot duct, and so on, respectively. Each of the air duct units 76a and 76b provides the capability for conditioned air to flow into the ducts or into a selected plurality of ducts.FIG. 23 is a plan view of the evaporator 40 corresponding to the plan view of FIG. 2, and a position of the center plate 73 is indicated by a dotted line. The center plate 73 is positioned at a center of the evaporator 40. The center plate 73 is positioned parallel to the longitudinal direction of the cooling pipe 45. The center plate 73 is positioned on a direct downstream side of the cooling pipe 45 located at the center of the evaporator 40. An upstream end portion of the center plate 73 is close to the center cooling pipe 45, or is in contact with the center cooling pipe 45 directly or indirectly via a cushion member. As a result, the central plate 73 divides the heat exchange region of the evaporator 40 into two heat exchange regions each of which is respectively in flow communication with the air flow passages in the temperature adjusting unit 72 divided by the central plates 73.According to the present embodiment, seven cold storage containers 47 are respectively disposed on a right side and on a left side of the center plate 73 in the bilateral direction of arrangement of the cooling tubes 45. Namely, the same number of cold storage containers 47 are arranged on both sides of a center line of the evaporator 40 aligned with the center plate 73. Since each of the cold storage containers 47 has the same capacity for a cold storage material 50, the same amount of cold storage material 50 is also disposed on both sides of the center line. Accordingly, a difference in the cold energy storage amounts or storage amounts or the cold energy storage effect between the driver side and the passenger side can be suppressed. For example, when stored cold energy is radiated, a temperature difference between the driver side and the passenger side can be suppressed.Further, a plurality of cold storage containers 47 are arranged symmetrically with respect to the center plate 73. Therefore, a temperature difference between the driver side and the passenger side can be suppressed. In other words, a symmetric temperature distribution can be achieved by the air mix doors 75 aand 75 b, the heater cores 74 aand 74 b, and the air passage units 76 aand 76 b, which are symmetrically arranged. Further, in each of the air flow passages, many cold storage containers 47 are arranged similarly, so that temperature distribution in the respective air flow passages can be suppressed.(Twelfth Embodiment)FIG. 24 is a plan view illustrating an evaporator 1240 according to a twelfth embodiment. Like reference numerals according to the above-explained embodiments are used for those portions in the present embodiment which are the same as those in the above-explained embodiments. The evaporator 1240 is applied to an air conditioner 70 of the above-explained embodiment (FIG. 22 ).The evaporator 1240 includes three cold storage containers 47 on the right side and the left side of the center plate 73, respectively. namely, the same number of cold storage containers 47 are arranged on both sides of the center plate 73 (the center line of the evaporator). Accordingly, the same amount of the cold storage material 50 is also disposed on both sides of the center plate 73. As a result, a temperature difference between the driver side and the passenger side can be suppressed.Moreover, many cold storage containers 47 are arranged symmetrically with respect to the center plate 73. Accordingly, a difference in temperature distribution between the driver side and the passenger side (side of the ride-on) can be suppressed. In other words, it is possible to provide a symmetrical temperature distribution.In each of the heat exchange regions of the evaporator 40, three cold storage containers 47 are disposed so as to be positioned close to a center of the respective air flow passages. As a result, generation of an excessive temperature distribution in each of the air flow passages is prevented. The evaporator 1240 may be applied to an air conditioner having a single air flow passage without the center plate 73.(Thirteenth Embodiment)FIG. 25 is a plan view illustrating an evaporator 1340 according to a thirteenth embodiment. Like reference numerals according to the above-explained embodiments are used for those portions in the present embodiment which are the same as those of the above-explained embodiments. The evaporator 1340 is applied to the air conditioner 70 of the above-explained embodiment (FIG. 22 ).The evaporator 1340 of FIG. 25 is different from the evaporator 1240 of FIG. 24 in that the cold storage containers 47 are not symmetrically arranged in FIG. 25. The evaporator 1340 includes three cold storage containers 47 on the right side and on the left side of the center plate 73, respectively. Accordingly, the same amount of cold storage material 50 is also disposed on both sides of the center plate 73. As a result, a temperature difference between the driver side and the passenger side can be suppressed.The cold storage containers 47 are arranged asymmetrically with respect to the center plate 73. In each of the heat exchange regions of the evaporator 40, three cold storage containers 47 are disproportionately disposed so as to be positioned on the left side. The asymmetric arrangement of the cold storage containers ensures an asymmetric temperature distribution. This type of construction may be useful when it is required to achieve a special requirement depending on a need for a disproportionate temperature distribution, which then results in a construction of the air conditioner 70. The evaporator 1340 may be applied to an air conditioner or air conditioner having a single air flow channel without the center plate 73.(Fourteenth Embodiment)FIG. 26 is a plan view illustrating an evaporator 1440 according to a fourteenth embodiment. Like reference numerals corresponding to the above-explained embodiments are used for those portions in the present embodiment which are the same as those of the above-explained embodiments. The evaporator 1440 is applied to an air conditioner 70 of the above-explained embodiment (FIG. 22 ).The evaporator 1440 includes five cold storage containers 47 on the right side of the center plate 73 and four cold storage containers 47 on the left side of the center plate 73. In other words, a different amount of the cold storage material 50 is disposed on the respective sides of the center plate 73. As a result, various effects can be obtained in terms of the cold energy storage operation for the driver side and the passenger side.The cold storage containers 47 are arranged asymmetrically with respect to the center plate 73. In each of the heat storage regions of the evaporator 40, the cold storage containers 47 are disproportionately arranged so that more cold storage containers 47 are positioned on the left side. The asymmetric arrangement of the cold storage containers provides an asymmetric temperature distribution. This type of construction may be useful when it is required to meet a specific requirement depending on a need for a disproportionate temperature distribution, which then results from a construction of the air conditioner 70. The evaporator 1440 can be applied to an air conditioner or air conditioner having a single air flow passage without the center plate 73.(Other Embodiments)The present invention is not limited to the above embodiments, but may be modified or modified in the following ways.For example, the cold storage containers may occupy 1 / 2, 2 / 5, 1 / 4, or 1 / 5 of the entire accommodation spaces formed between the adjacent cooling tubes 45.The length L of the cold storage container 47 may be shorter than the length of the cooling pipe 45 or the fin 46.In a case where the inner fin is disposed inside the cold storage container, a plurality of openings may be formed on the main wall portions to allow each of the upper portions of the corrugated or corrugated inner fin to be inserted into the corresponding openings, and the upper portions may be directly in contact with the cooling tubes.Cooling tubes may be formed by an extrusion process, or may be formed or manufactured by bending plates having a plurality of recesses. The rib 46 may be removed. The heat exchanger of this type (without fins) is also referred to as a finless heat exchanger. Instead of the fins, a plurality of protrusions may be formed on outer surface portions of the cooling tubes to thereby increase heat exchange with air.The present invention can also be applied to evaporators having a variety of refrigerant streams. For example, the present invention can be applied also to an evaporator in which the refrigerant does not flow in a U-shaped path at a front or rear plane of the first and second heat exchange portions, but in a one-way straight path or in a U-shaped path formed by the first and second heat exchange portions at a plane in the direction of the air flow.Further, the present invention can also be applied to a refrigerating cycle for a freezing storage, a heating operation or a hot water supply apparatus.

Claims

A cold storage heat exchanger (40) comprising: first and second header tanks (41, 42); a plurality of cooling tubes (45) arranged at intervals between the first and second header tanks (41, 42) such that a coolant flows through the cooling tubes (45) from at least one of the tanks according to the first and second header tanks (41, 42) to the other header tank (41, 42), wherein the cooling tubes (45) comprise a first cooling tube, a second cooling tube, a third cooling tube, a fourth cooling tube, and a fifth cooling tube, wherein the cooling tubes (45) are arranged in the order of a first cooling tube, a second cooling tube, a third cooling tube, a fourth cooling tube, and a fifth cooling tube; a first cold storage container (47; 247; 347; 547; 647; 747e, 747f; 847; 947) which is disposed in a first accommodation space which is formed between the second and third cooling tubes and which is directly fixed to the second and third cooling tubes on both sides of the first cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947), a cold storage material (50) which is inserted into an inner side of the first cold storage container (47, 347); a first air passage forming space which is formed between the first cooling tube and the second cooling tube; a second air passage forming space which is formed between the third cooling tube and the fourth cooling tube; a third air passage forming space which is formed between the fourth cooling tube and the fifth cooling tube; a plurality of fins (46) provided in the first to third air passage forming spaces, respectively, so that the fins (46) provided in the second and third air passage forming spaces are directly fixed to the fourth cooling tube on both sides of the fourth cooling tube; a heat exchange portion (47b; 247b; 347b; 547b; 647b) provided in the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) and protruding into the inside of the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947), wherein the accommodation spaces formed between adjacent cooling tubes (45) and on both sides of the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) are formed as air passages through which air for heat exchange with the coolant flowing through the first to fifth cooling tubes (45) passes.The cold storage heat exchanger (40) according to claim 1, wherein the cooling tubes (45) are arranged at equal intervals, and the width (T) of the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) is equal to that of the air passage.The cold storage heat exchanger (40) according to any one of claims 1 or 2, wherein an occupancy ratio of the cold storage container (47) occupying the accommodation spaces formed between the cooling tubes (45) is between 10% and 50% with respect to an entire space of the accommodation spaces formed between the cooling tubes (45).The cold storage heat exchanger (40) according to any one of claims 1 to 3, wherein the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) is joined to the cooling tubes (45) by brazing material.The cold storage heat exchanger (40) according to any one of claims 1 to 4, wherein the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947) is composed of a pair of main wall portions (47a; 447a) and a plurality of partitioning portions (47b; 447b), each of the partitioning walls or partitions extending from one of the wall portions (47a; 447a) toward the other wall portion (47a; 447a).The cold storage heat exchanger (40) according to any one of claims 1 to 4, wherein the heat exchange portion is formed by an inner fin (247b; 347b) provided in the cold storage container (247, 347).The cold storage heat exchanger (40) according to any one of claims 1 to 4, wherein the heat exchange portion is formed by protrusions (47b; 447b; 547b; 647b), each of which protrudes from one of the wall portions (47a; 447a; 547a; 647a) of the cold storage container (47, 447, 547, 647) toward the other wall portion (47a; 447a; 547a; 647a).The cold storage heat exchanger (40) according to any one of claims 1 to 7, further comprising: a plurality of cold storage containers (47; 247; 347; 547; 647; 747e, 747f; 847; 947) containing the former cold storage container, wherein each of the cold storage containers (47, 247, 347, 547, 647, 747e, 747f, 847, 947) is disposed in respective accommodation spaces formed between adjacent cooling tubes (45), and wherein the cold storage containers (47, 247, 347, 547, 647, 747e, 747f, 847, 947) are disposed at equal intervals.The cold storage heat exchanger (40) according to any one of claims 1 to 8, further comprising: a plurality of cold storage containers (47; 247; 347; 547; 647; 747e, 747f; 847; 947) containing the former cold storage container, wherein each of the cold storage containers (47, 247, 347, 547, 647, 747e, 747f, 847, 947) is disposed in respective accommodation spaces formed between adjacent cooling tubes (45), and wherein the cold storage containers (47, 247, 347, 547, 647, 747e, 747f, 847, 947) are uniformly disposed on right and left sides of the heat exchanger with respect to a center (73) thereof.The cold storage heat exchanger (40) according to claim 9, wherein the cold storage containers (47, 247, 347, 547, 647, 747e, 747f, 847, 947) are symmetrical with respect to the center (73) of the heat exchanger (40).The cold storage heat exchanger (40) according to any one of claims 1 to 10, wherein a heat exchange portion formed by the cooling tubes (45), the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947), and the air passage forming spaces is in flow communication with a single air flow passage formed in an air conditioner on a downstream side of the heat exchanger (40).The cold storage heat exchanger (40) according to any one of claims 1 to 10, wherein a heat exchange portion formed by the cooling tubes (45), the cold storage container (47, 247, 347, 547, 647, 747e, 747f, 847, 947), and spaces forming the air passages is divided into two heat exchange portions, and each of the heat exchange portions is in flow communication with the respective air flow passages formed in an air conditioner case on a downstream side of the heat exchanger (40).The cold storage heat exchanger (40) according to any one of claims 1 to 12, wherein the heat exchanger (40) includes two-layer first and second heat exchange portions (48, 49), a cold storage container (47; 747e), and two cooling tubes (45) disposed on both sides of the cold storage container form a first cold storage unit disposed in the first heat exchange portion (48), another cold storage container (47; 747 f) and two other cooling tubes ( 45) disposed on both sides of the other cold storage container form a second cold storage unit disposed in the second heat exchange portion ( 49), the first and second cold storage units being aligned with each other in a direction of the air flow passing through the heat exchanger, and the first and second cold storage units being separated from each other to form a space therebetween functioning as a heat insulator.The cold storage heat exchanger (40) according to any one of claims 1 to 12, wherein the heat exchanger (40) includes first and second heat exchange portions (48, 49) formed of two layers, a cold storage container (847; 947), and two cooling tubes (45) disposed on both sides of the cold storage container form a first cold storage unit disposed in the first heat exchange portion (48), another cold storage container (847; 947) and two other cooling tubes (45) disposed on both sides of the other cold storage container form a second cold storage unit disposed in the second heat exchange portion (49), the first and second cold storage units are aligned with each other in a direction of the air flow passing through the heat exchanger, and the first and second cold storage units are joined with each other by a partition wall (847g) or a restricted portion (947h) serving as a heat insulator.The cold storage heat exchanger (40) according to any one of claims 1 to 5, wherein the heat exchanger (40) includes two-layered first two and second heat exchange portions (48, 49), the first heat exchange portion (48) includes first and second header tanks (41, 42) connected to both ends of the cooling tubes (45), the first header tank (41) being divided into first and second header portions by a separator provided inside the first header tank (41) so that the refrigerant flows in a U-shaped path from the first header portion of the first header tank (41) to the second header portion of the first header tank (41) through a first tube group of the cooling tubes (45), the second header tank (42), and a second tube group of the cooling tubes (45), the second heat exchanging portion (49) has third and fourth header tanks (43, 44) connected to both ends of the cooling tubes (45), the third header tank (43) is divided into first and second header sections by a separator provided inside the third header tank (43), the first header section of the third header tank (43) is in flow communication with the second header section of the first header tank (41) so that the coolant flows in a U-shaped path from the first header section of the third header tank (43) to the second header section of the third header tank (43) through a first tube group of the cooling tubes (45), the fourth header tank (44), and through a second tube group of the cooling tubes (45).

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