Heat exchanger

Abstract: The invention has as an object providing a two-block heat exchanger that can improve the heat exchange capacity by distributing the refrigerant evenly in the refrigerant path. The invention is a two-block heat exchanger, and the refrigerant distribution part provides two separate refrigerant paths R1 and R2 through which the refrigerant flows and an opening provided at both of the respective ends of these refrigerant paths R1 and R1. Among the two refrigerant paths R1 and R2, the open end of the space Sout 1 (refrigerant circulation space) on the exit side formed by the one opening of the one refrigerant path R1 is connected to the open end of the space Sin 2 (refrigerant circulation space) on the entrance side formed by one opening of the other refrigerant path R2. After the refrigerant flows into the refrigerant path R1 of each refrigerant distribution part, and refrigerant flows through the refrigerant path R2 of each of the refrigerant distribution parts.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a heat exchanger mounted on an air conditioning device and the like. Description of the Related Art Fig. 9 shows an example of a two-block heat exchanger used as an evaporator in an automobile air conditioning system and the like. The heat exchanger shown in the figure is referred to as a drawn cup type, and is formed by plate-shaped refrigerant distribution parts 3 comprising overlapping superimposed rectangular plates 1 and 2 on which a drawing process has been carried out and cooling fins 4 that have been bent into an wave shape, the overlapping rectangular plates 1, 2 and the cooling fins 4 being alternately layered. In the refrigerant distribution parts 3, the periphery and center of the plates 1 and 2 are brazed, and thereby a U-shaped refrigerant path R is formed that goes from the refrigerant entrance 5 provided at the top, descending to and returning from the bottom for discharge into the refrigerant exit 6 provided at the top and arranged next to the refrigerant entrance. In this heat exchanger, the refrigerant is distributed among each of the refrigerant distribution parts 3 in the refrigerant entrance 5, is evaporated in the process of flowing through in the refrigerant paths R, merges together again in the refrigerant exit 6, and flows out of the heat exchanger. However, problems such as the following can be pointed out concerning the heat exchanger having the structure described above. Specifically, as shown in Fig. 10, a continuous space T (below referred to as a tank) is formed by the layering of refrigerant entrances 5, and the refrigerant flow into the heat exchanger is distributed to each of the refrigerant distribution parts 3 in the process of progressing through this continuous space in the direction of the arrows in the figure. However, in the conventional heat exchanger, the refrigerant supplied to the tank T passes with difficulty to the back of the tank T and there is a tendency for much of the refrigerant to flow through the upstream side of the refrigerant paths R. Thus, the flow of the refrigerant stagnates in the downstream side of the tank T. Due to this, the distribution of refrigerant to each of the refrigerant distribution parts 3 cannot be carried out uniformly, and at the refrigerant path R of the tank T positioned downstream, the refrigerant becomes hot, and the heat exchange cannot be sufficiently carried out. In consideration of the problem described above, it is an object of the present invention to provide a heat exchanger that can realize an improvement in the heat exchange capacity by evenly distributing the refrigerant in the refrigerant paths. SUMMARY OF THE INVENTION A first aspect of the present invention is characterized in a heat exchanger according to the features of claim 1. In the present invention, in the two-block heat exchanger in which each refrigerant distribution part has a two-row refrigerant path, once the refrigerant that flows through one of the refrigerant paths flows out into the refrigerant circulation space, subsequently, it flows through the other refrigerant path. In this manner, because the refrigerant flows though each of the two refrigerant paths, the stagnation of the refrigerant is prevented, and heating occurs with difficulty. Besides, a heat exchanger according to the features of claim 1 has a refrigerant distribution means that adjusts the amount of refrigerant supplied to the refrigerant path provided on at least one of the refrigerant circulation spaces. Document EP 769,665 discloses a heat exchanger comprising the features of the preamble part of claim 1. The object of the invention is to improve the adjustment of the amount of refrigerant flowing into each refrigerant path. Because the amount of refrigerant flowing into each refrigerant path is controlled, the uniformity is further improved. This object is achieved, in a heat-exchanger as defined in the preamble part of claim 1, by the additional features of the characterizing part of this claim. Specific constructions of this heat exchanger are defined in the sub-claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective drawing showing an embodiment of the heat exchanger according to the present invention. Fig. 2 is a perspective drawing viewing the same heat exchanger from the back. Fig. 3 is an exploded perspective drawing showing the refrigerant distribution part that forms the heat exchanger in Fig. 1. Fig. 4 is a cross-sectional drawing showing the space at the entrance side and the refrigerant path connected thereto. Fig. 5 is a cross-sectional drawing showing the space at the exit side and the refrigerant path connected thereto. Fig. 6 is a drawing showing an embodiment similar to this same heat exchanger, and is a time sequence drawing formed at each baffle plate. Fig. 7 is a modification of the present invention, and is a cross-sectional drawing showing the space at the entrance side and the refrigerant path connected thereto. Fig. 8 is a perspective drawing viewing the heat exchanger shown as a modification of the present invention form the back. Fig. 9 is a perspective drawing showing an example of the conventional evaporator. Fig. 10 is a cross-sectional drawing showing the space the entrance side and the refrigerant path connected thereto in a conventional evaporator. DETAILED DESCRIPTION OF THE INVENTION Next, the preferred embodiments of the present invention will be explained referring to the figures. The heat exchanger shown in Fig. I is formed by plate shaped refrigerant distribution parts 11 and wave shaped refrigerant fins 12 being alternatively layered. Fig. 2 is a perspective drawing of the heat exchanger seen from the back side. As also shown in Fig. 5, the refrigerant distribution parts 11 comprise superimposed substantially rectangular plates 13 and 14, which have been drawing processed, layered and brazed at the periphery and center thereof. In the refrigerant distribution parts 11, independent refrigerant paths R1 and R2 through which the refrigerant flows are provided next to each other. In the lower part, the refrigerant entrance 15a of the refrigerant path R1 and the refrigerant exit 16b of the refrigerant path R2 are provided next to each other. In the upper part, the refrigerant exit 15b of the refrigerant path R1 and the refrigerant entrance 16a of the refrigerant path R2 are provided next to each other. In the refrigerant distribution part 11, the plates 13 and 14 that form the refrigerant paths R1 and R2 are recessed from the outside to form a plurality of dimples 17, and a plurality of bulge parts 18 are formed in the refrigerant paths R1 and R2 by these dimples 17. Moreover, inner fins can be sandwiched between the plates 13 and 14 to form the refrigerant paths R1 and R2 as well. As shown in Fig. 3, the refrigerant entrance 15a comprises openings 13-1a and 14-1a formed respectively in the plates 13 and 14, and as shown in Fig. 4, the refrigerant entrances 15a provided on each of the refrigerant distribution parts 11 form a continuous space Sin 1 (the refrigerant circulation space) on the entrance side by the fact that the refrigerant fins 12 are shorter than the plates 13 and 14. Similarly, the refrigerant exit 15b comprises openings 13-1b and 14-1b formed in the plates 13 and 14, and as shown in Fig. 5, the refrigerant exit 15b provided on each of the refrigerant distribution parts 11 forms a continuous space Sout 1 (refrigerant circulation space) on the exit side by the fact that the refrigerant fins 12 are shorter than the plates 13 and 14. Although not illustrated, similarly, the refrigerant entrance 16a comprises the openings 13-2a and 14-2a formed in the plates 13 and 14 and forms the space Sin 2 (the refrigerant circulation space) on the entrance side, and the refrigerant exit 16b comprises the openings 13-2b and 14-2b formed in plates 13 and 14, and forms the space Sout 2 (refrigerant circulation space) on the exit side (refer to Fig. 1). Specifically, in the refrigerant distribution part 11, the space Sin 1 on the entrance side and the space Sout 2 on the exit side are respectively positioned in fluid communication with the space Sout 1 on the exit side and space Sin 2 on the entrance side. In addition, as shown in Fig. 1, one end of the space Sout 1 on the exit side and space Sin 2 on the entrance side is closed off, and the other end shown in Fig. 2 is connected by the communicating path 30. In the heat exchanger having the structure described above, the refrigerant is distributed in each of the refrigerant distribution parts 11 by the process of progressing through the space Sin 1 on the entrance side in the direction of the arrow shown in the figure, is evaporated by the process of flowing through each of the refrigerant paths R1, and merged in the space Sout 1 on the exit side. Next, passing through the communicating path 30, the refrigerant progresses through the space Sin 2 on the entrance side in the direction opposite to that of the space Sout 1 on the exit side, and by this process, the refrigerant is distributed to each of the refrigerant distribution parts 11, further evaporated by a process of flowing through each of the refrigerant paths R2, and again merges and flows into the space Sout on 2 the exit side. However, as can be understood from Fig. 3, the opening 13-1a in the plate 13 that forms the refrigerant entrance 15a is formed smaller than the opening 14-1a of the plate 14 that similarly acts as the refrigerant entrance 15a. Further, as shown in Fig. 4, an opening 14-1a is formed at the same position in each of the refrigerant distribution paths 11, but the openings 13-1a are formed at respectively differing positions in each of the refrigerant distribution parts 11. This means that because the refrigerant distribution part 11 is layered, the part that forms the opening 13-1a provides a function as an baffle plate 20 (a cooling distribution means) that prevents flow of the refrigerant to the opening 14-1a forming the refrigerant entrance 15a. The openings 13-1a are provided on the adjacent baffle plate 20 and disposed so as not to overlap completely with their two adjacent openings 13-1a in the direction of flow of the refrigerant. Moreover, although omitted in the figures, the opening 14-2a of the plate 14 forming the refrigerant entrance 16a is structured similarly (refer to Fig. 3). Below, the space Sin 1 on the entrance side will be explained, but the explanation is similar for the space Sin 2 on the entrance side as well. In this heat exchanger, the refrigerant that flows through the space Sin 1 on the entrance side flows downstream while passing through the openings 13-1a formed by each of the baffle plates 20, and the part of the refrigerant that cannot pass through the opening 13-1a is guided by the baffle plates 20 to flow into the refrigerant path R1. Furthermore, because the openings 13-1a are disposed so as not to overlap completely the openings 13-1a of the adjacent baffle plates 20 that are provided, a part of the refrigerant that passes, for example, through the opening 13-1a of the baffle plate 20a on the upstream side cannot pass through the opening 13-1a because the flow is blocked by the baffle plate 20b when flowing through the opening 13-1a of the adjacent baffle plate 20b (refer to fig. 4). In this manner, because the openings 13-1a provided in the adjacent baffle plate 20 are disposed so as not to overlap completely each other, much of the refrigerant is distributed to the refrigerant distribution parts 11, where refrigerant tends to stagnate, and each of the refrigerant distribution parts 11 provided in plurality can distribute the refrigerant uniformly. Moreover, the number of openings 13-1a formed in each baffle plate 20 is not limited to one, but for example, as shown in Fig. 6, may be provided in plurality, and furthermore, the size of each of the openings 13-1a can be respectively formed so as to be different. In addition, the baffle plates 20 can also be provided on the plate 14 side. Furthermore, baffle plates 20 do not need to be formed on all of the plates 13 (14), and only need to be provided on at least one of plates 13 or 14 among the spaces Sin 1 and Sin 2 on the entrance side. Moreover, as an example of a modification, the structure described below is possible. Moreover, in the following as well, only the space Sin 1 on the entrance side will be explained, but the explanation for the space Sin 2 on the entrance side is similar. In the heat exchanger in the present example, as shown in Fig. 4 and 7, each opening 13-1a is formed larger than the corresponding opening 13-1a of the baffle plate 20 (21) positioned in the direction of flow of the refrigerant. For example, all the part of the refrigerant that passes through the opening 13-1a of the baffle plate 20a (21 a) on the upstream side cannot pass through the opening 13-1a of the baffle plate 20b (21b) because a part of the flow is deflected toward a refrigerant path R1 by the baffle plate 21b when passing through the opening 13-1a of the adjacent baffle plate 21b in the downstream direction. In this manner, because the openings 13-1a are formed increasingly smaller in the baffle plates 21 in the direction of flow of the refrigerant, the refrigerant can be distributed uniformly by all of the refrigerant distribution parts 11 which are provided in plurality. In the heat exchanger shown in fig 7, the openings 13-1a of the baffle plates 21 are furthermore concentrically aligned. In this manner, in the heat exchanger of the present example, the refrigerant flows through one side of the two refrigerant paths R1 and R2, and thus heating due to the stagnation of the refrigerant is prevented. In addition, in the spaces Sin 1 and Sin 2 on the entrance side, even if the flow of the refrigerant is reversed, the heat is dissipated because of the refrigerant flowing through the space Sin 2 of the entrance side. Furthermore, the refrigerant can be distributed more evenly in the refrigerant distribution part 11 because the refrigerant is distributed by the baffle plates 20 (21). Moreover, as shown in Fig. 8, because the spaces Sin 1 and Sin 2 on the entrance side and the spaces Sout 1 and Sout 2 on the exit side are positioned adjacently to each other, the space Sout 1 on the exit side and space Sin 2 on the entrance side can be connected by the communicating path 30'. As explained above, in the present invention, by providing a refrigerant distribution means, the refrigerant can be distributed more evenly.

Claims: A two-block heat exchanger including plate shaped refrigerant distribution parts (11) comprising two overlapped plates (13, 14) that have been drawing processed and between which two separate refrigerant paths (R1, R2) are formed, said distribution parts (11) being alternatively layered with a refrigerant fin (12), openings (13-1a, 13-1b, 13-2a, 13-2b; 14-1a, 14-1b, 14-2a, 14-2b) that open into said refrigerant paths (R1, R2) being respectively formed in each two plates (13, 14) of said refrigerant distribution parts (11) ; said openings (13-1a, 13-1b, 13-2a, 13-2b; 14-1a, 14-1b, 14-2a, 14-2b) being provided at both respective ends of said refrigerant paths (R1, R2) forming thereby, for each of said refrigerant paths (R1, R2) of each of said distribution part (11), a refrigerant entrance (15a, 16a) and a refrigerant exit (15b 16b), a continuous refrigerant circulation space (Sin 1, Sin 2) being formed by abutting said refrigerant entrances (15a, 16a) at the entrance side of respective refrigerant paths (R1, R2) and a continuous refrigerant circulation space (Sout 1, Sout 2) being formed by abutting said refrigerant exits (15b, 16b) at the exit side of respective refrigerant paths (R1, R2) ; and one end of each of said refrigerant circulating spaces (Sin 1, Sin 2, Sout 1, Sout 2) being closed off and the other end being opened, the open end of said refrigerant circulation space (Sout 1) at the exit side of said one refrigerant path (R1) being connected to the open end of said refrigerant circulation space (Sin 2) at the entrance side of said other refrigerant path (R2) ; characterized in that , in at least one of said refrigerant circulation spaces (Sin 1, Sin 2) at the entrance side of said refrigerant paths (R1, R2), a refrigerant distribution means adjusts the amount of refrigerant supplied to said refrigerant path (R1, R2), said refrigerant distribution means being formed by a baffle plate (20, 21) formed at the end of at least one of said two plates (13, 14) around said openings (13-1a, 13-2a, 14-1a, 14-2a) in order to prevent that all the refrigerant present in the refrigerant entrance (15a, 16a) positioned upstream said baffle plate (20, 21) flows into the refrigerant entrance (15a, 16a) positioned downstream said baffle plate (20, 21); and in that , each of said openings (13-1a, 13-2a, 14-1a, 14-2a) of said baffle plates (20, 21) is larger than the corresponding opening (13-1a, 13-2a, 14-1a, 14-2a) of the adjacent baffle plate (20, 21) in the direction of flow of the refrigerant. Heat exchanger according to claim 1, characterized in that each of said openings (13-1a, 13-2a, 14-1a, 14-2a) of said baffle plates (20, 21) is disposed so as not to completely overlap the corresponding opening (13-1a, 13-2a, 14-1a, 14-2a) of said adjacent baffle plate (20, 21) in the direction of flow of the refrigerant. Heat exchanger according to claim 1, characterized in that said openings (13-1a, 13-2a, 14-1a, 14-2a) of said baffle plates (20, 21) are concentrically aligned. Heat exchanger according to any one of claims 1 to 3, characterized in that the refrigerant entrance (15a) of said one refrigerant path (R1) is provided adjacent to the refrigerant exit (16b) of said other refrigerant path (R2) and in that a communicating path (30) connects said open end of said refrigerant circulation space (Sout 1) at the exit side of said one refrigerant path (R1) to the open end of said refrigerant circulation space (Sin 2) at the entrance side of said other refrigerant path (R2). Heat exchanger according to any one of claims 1 to 3, characterized in that the refrigerant entrance (15a) of said one refrigerant path (R1) is provided adjacent to the refrigerant entrance (16a) of said other refrigerant path (R2) and in that a communicating path (30') connects said open end of said refrigerant circulation space (Sout 1) at the exit side of said one refrigerant path (R1) to the open end of said refrigerant circulation space (Sin 2) at the entrance side of said other refrigerant path (R2).

Inventors: KATSUHIRO SAITO, MASASHI INOUE, KATSUHIRO, SAITO, MASASHI, INOUE, Katsuhiro, Saito, Mitsubishi Heavy Ind. Ltd., Masashi, Inoue, Mitsubishi Heavy Ind. Ltd.
Applicants: MITSUBISHI HEAVY IND LTD, MITSUBISHI HEAVY INDUSTRIES, LTD.
Application year: 2001
Main classification: F28D1
IPC codes: F28D1, F28F9, F28F27, F28F13, F28F3