This application is based on Japanese Patent Application No. 2005-303660 filed on Oct. 18, 2005, the contents of which are incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to an evaporator for a refrigerant cycle device.
2. Description of the Related Art
In a refrigerant evaporator for a refrigerant cycle device described in U.S. Pat. No. 6,308,527 (corresponding to JP-A-2000-179988), a fin pitch is set smaller in order to obtain a predetermined heat transferring area when the size of the evaporator is made small. However, when the fin pitch is made small, condensed water generated on the evaporator easily becomes in a water film shape on the outer surface of the evaporator by the surface tension between adjacent fin surfaces, thereby increasing a water amount staying on the outer surface of the evaporator. When the water amount staying on the evaporator is increased, the condensed water flows toward a downstream air side together with an air flow. Therefore, the condensed water may fly (scatter) into a compartment due to the air flow.
To reduce the water flying amount, clearance portions may be provided between adjacent fins at a position corresponding to a space portion between tube members, in the air flow direction, as described in U.S Pat. No. 6,308,527. However, in this structure of U.S. Pat. No. 6,308,527, the strength of the evaporator is reduced at positions where the clearance portions and drain water grooves are provided. Furthermore, in this evaporator, vibration noise due to a refrigerant flow may be easily caused.
In view of the foregoing problems, it is an object of the present invention to provide an evaporator which reduces a water flying amount from the surface of an evaporator while increasing the strength of the evaporator.
According to a first example of the present invention, an evaporator includes a plurality of passage members having therein refrigerant passages in which refrigerant flows, and a fin having a heat exchanging surface extending along the flow direction of air. The passage members are arranged in a flow direction of air flowing outside of the passage members, and the fin is located adjacent to the passage members in a direction perpendicular to the flow direction of air. Furthermore, the fin has an open portion opened at a position adjacent to the one of the refrigerant passages, and a bridge portion joined to the passage members. Therefore, the passage members are connected to each other in the flow direction of air by the bridge portion. Accordingly, water draining performance can be increased, thereby reducing a water flying amount flying toward a downstream air side together with the air flow. Because the passage members are connected to each other by the bridge portion, the strength between the passage members can be increased, thereby increasing the strength of the evaporator.
For example, the fin includes a plurality of fin parts arranged in the flow direction of air, the open portion is a slit opening provided between adjacent fin parts adjacent to each other in the flow direction of air, and the slip opening extends partially in the fin in a direction approximately perpendicular to the flow direction of air such that the fin has a connection portion between the fin pars. In this case, the bridge portion is one of the fin parts. Alternatively, the open portion is a clearance opening that is provided between adjacent fin parts to separate the adjacent fin parts from each other in the flow direction of air. Even in this case, the bridge portion may be used as one of the fin parts. Alternatively, the bridge portion may be a part of the fin, without having the open portion.
The open portion may be provided in the fin at a portion in the flow direction of air, except for an area corresponding to a space portion between the passage members in the flow direction of air. Alternatively, the open portion may include a plurality of openings provided in the fin at plural positions in the flow direction of air, except for an area corresponding to a space portion between the passage members in the flow direction of air.
According to a second example of the present invention, an evaporator includes: a plurality of tubes stacked in a stacking direction; a plurality of fins each of which is located between adjacent tubes in the stacking direction; and a tank portion extending to the stacking direction to be connected to one longitudinal end of each tube. In the evaporator, each of the tubes includes at least first and second tube parts lined to have a space therebetween in a flow direction of air passing between the adjacent tubes. Here, the flow direction of air is perpendicular to the stacking direction and a tube longitudinal direction. The first tube part has therein a first refrigerant passage through which refrigerant flows, the second tube part has therein a second refrigerant passage through which refrigerant flows, and the second refrigerant passage is separate from the first refrigerant passage. In addition, the fin extends from the first tube part to the second tube part, the fin has at least one open portion that is opened from an end of the fin in the stacking direction to a predetermined portion, and the open portion is provided in the fin except for a position in the air flow direction, corresponding to the space between the first and second tube parts. Accordingly, the water draining performance can be increased using the open portion, and strength of the evaporator can be increased.
Additional objects and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments when taken together with the accompanying drawings. In the drawings:
The first embodiment will be now described with reference to
The evaporator 10 is a part of a refrigerant cycle device that is constructed with a compressor, a refrigerant radiator, an expansion valve, etc., together with the evaporator 10. Generally, refrigerant decompressed by the expansion valve flows into the evaporator 10 from a refrigerant inlet portion 1. The refrigerant flowing into the refrigerant inlet portion 1 flows through all refrigerant paths of the evaporator 10 as in the arrows shown in
The evaporator 10 includes the core portion 13 and first and second header tanks 2a, 2b. In the arrangement state of the evaporator 10 shown in
The core portion 13 includes a plurality of tubes 5 and a plurality of fins 4 which are stacked alternately in a stacking direction (i.e., the width direction W of the core portion 13, tank longitudinal direction). Side plates 3 each of which has approximately a U-shaped cross section are located at the outer ends of the core portion 13 in the width direction W, and are used as a strengthening member for improving the strength of the core portion 13.
The tubes 5 are arranged in two layers in an air flow direction, for example. The tubes 5 are constructed of first tubes 5a arranged at an upstream air side, and second tubes 5b arranged at a downstream air side of the first tubes 5a in the air flow direction. As shown in
Each of the tubes 5 is a flat tube extending in a tube longitudinal direction approximately perpendicular to the air flow direction and the tube stacking direction. The flat tube 5 has a cross section having a major dimension in the air flow direction. Therefore, the flat tube 5 has side surfaces extending along the air flow direction. In this embodiment, a pair of the first and second tubes 5a and 5b are lined in the air flow direction to have a predetermined distance (predetermined space) therebetween. Furthermore, plural pairs of the first and second tubes 5a and 5b are arranged in the tube stacking direction, and the fin 4 is located between the adjacent tubes 5a, 5b in the tube stacking direction.
The fins 4 are joined and bonded to adjacent tubes 5 so that heat transferring performance between the refrigerant flowing in the tubes 5 and air passing through the core portion 13 between adjacent tubes 5 can be increased. The fin 4 is corrugated fin formed into a wave shape having ridge portions and flat surface portions. In the fin 4, each of the flat surface portions is positioned between adjacent ridge portions. The ridge portions of the fin 4 are joined to adjacent tubes 5 in the tube stacking direction, and the flat surfaces of the fin 4 extends along the air flow direction between the adjacent tubes 5. That is, as shown in
The first header tank 2a is located at one longitudinal ends of the tubes 5 to communicate with the one longitudinal ends of the tubes 5, and the second header tank 2b is located at the other longitudinal ends of the tubes 5 to communicate with the other longitudinal ends of the tubes 5. Each of the first and second header tanks 2a, 2b includes a tube insertion plate 7, a tank plate 9 and side plates 8.
The tube insertion plate 7 is formed into an approximately U shape having tube insertion holes into which the tubes 5 are inserted. The tank plate 9 is formed by pressing, and is joined to the tube insertion plate 7 to form a tank space between the tank plate 9 and the tube insertion plate 7. The side plates 8 are connected to two sides of the tank plate 9 and the tube insertion plate 7 in the tank longitudinal direction.
In this embodiment, the evaporator 10 is a two-path type in which opposite refrigerant streams are formed in the core portion 13 at two refrigerant path areas. For example, in this embodiment, one path is constructed by W/2 of the width dimension W of the core portion 13. Therefore, the inner space of the first header tank 2a is partitioned into four thank space parts, that is, a first tank space part communicating with the second tubes 5b in the first path, a second tank space part communicating with the second tubes 5b in the second path, a third tank space part communicating with the first tubes 5a in the first path, and a fourth tank space part communicating with the first tubes 5a in the second path. In contrast, the inner space of the second header tank 2b is partitioned into two tank space parts, that is, a first tank space part communicating with all the second tubes 5b, and a second tank space part communicating with all the first tubes 5a. Therefore, refrigerant flowing through the tubes 5a, 5b can be U-turned, respectively, in the first and second tank space parts of the second header tank 2b.
A joint member 12 for forming the refrigerant inlet portion 1 and the refrigerant outlet portion 11 are provided at one end of the first header tank 2a. For example, the refrigerant outlet portion 11 is provided at an upper portion in the joint member 12, and the refrigerant inlet portion 1 is provided at a lower portion of the refrigerant outlet portion 11 in the joint member 12. The refrigerant outlet portion 11 is coupled to a refrigerant suction side of the compressor, and the refrigerant inlet portion 1 is coupled to the expansion valve of the refrigerant cycle device.
As shown in
In this embodiment, a pair of the first tube 5a and the second tube 5b are lined in the air flow direction to have the predetermined space therebetween. Furthermore, the connection portion 18 having the slits 18a, 18b is located at a position outside of the first tube 5a, and the connection portion 19 having the slits 19a, 19b is located at a position outside of the second tube 5b. That is, the connection portions 18, 19 are provided at positions in the air flow direction, where the first and second tubes 5a, 5b are positioned. Therefore, the connection portions 18, 19 are not plated at the position adjacent to the predetermined space between the first and second tubes 5a, 5b, in the air flow direction. The slits 18a, 19a are opened from the ridge portions of the corrugated fin 4 to the connection portions 18, 19 in the flat surface portions of the corrugated fin 4, at one end side adjacent to a pair of the tubes 5a, 5b. The slits 18b, 19b are opened from the ridge portions of the corrugated fin 4 to the connection portions 18, 19 in the flat surface portions, at the other end side opposite to the slits 18a, 18b in the tube stacking direction.
As shown in
Because the first and second tubes 5a, 5b arranged in the air flow direction are connected by the second fin part 4b, the strength between the first and second tubes 5a, 5b can be increased, thereby increasing the strength of the core portion 13 and the evaporator 10. Therefore, the second fin part 4b functions as a bridge portion for connecting plural tubes (e.g., two tubes 5a, 5b in this embodiment) in the air flow direction.
Plural louvers 17 are provided in each of the first to third fin parts 4a, 4b, 4c. As shown in
Each of the first to third fins 4a, 4b, 4c is formed into the wave shape extending from the first tank 2a to the second tank 2b in the tube longitudinal direction.
The evaporator 10 may be arranged such that the tubes 5 (5a, 5b) extend approximately in a vertical direction, as shown in
Next, the arrangement positions of the connection portions 18, 19 in the evaporator 10 will be described with reference to
Therefore, when the slits 18a, 18b are provided at a position X1 where X1/D is in a range between 0.25 and 0.5 (0.25≦X1/D≦0.5), the water draining performance can be effectively improved. Here, X1 is a position from the most upstream end of the fin 4 (core portion 13) in the air flow direction, and D is the entire dimension of fin 4 (core portion 14) in the air flow direction. Furthermore, when the slits 18a, 18b are provided at a position X1 where X1/D is in a range between 0.25 and 0.35 (0.25≦X1/D≦0.35), the water draining performance can be more improved. In this case, about 50% of the condensed water generated on the entire dimension D of the evaporator 10 can be drawn downwardly through the slits 18a, 18b by its weight without flying to the compartment together with the air flow.
Furthermore, when the slits 19a, 19b are provided at a position X2 where X2/D is in a range between 0.5 and 0.75 (0.5≦X2/D≦0.75), the water draining performance can be effectively improved on the downstream air side of the evaporator 10. Here, X2 is a position from the most upstream end of the fin 4 (core portion 13) in the air flow direction, and D is the entire dimension of fin 4 (core portion 13) in the air flow direction. Furthermore, when the slits 19a, 19b are provided at a position X2 where X2/D is in a range between 0.65 and 0.75 (0.65≦X2/D≦0.75), the water draining performance on the downstream air side of the evaporator 10 can be more improved. In this case, about 95% of the condensed water generated on the entire dimension D of the evaporator 10 can be drawn downwardly through the slits 19a, 19b by its weight without flying to the compartment together with the air flow.
Accordingly, in a case where 0.25≦X1/D≦0.35 in the fin 4, about 50% of the condensed water generated on the evaporator 10 can be drained through the slits 18a, 18b, thereby reducing the amount of the condensed water flowing to the downstream air side on the evaporator 10. Therefore, condensed water flowing from the position X1 to the position X2 can be quickly drained and removed through the slits 19a, 19b, and drain performance of the evaporator 10 can be further improved. For example, the dimension of each of slits 18a, 18b, 19a, 19b can be set in a range of 0.5 mm-1.0 mm.
As shown in
Furthermore, when the slits 18a, 18b and the slits 19a, 19b are provided in the fin 4 at plural positions (e.g., two positions) in the air flow direction, the air flow limit for causing the water fly can be further increased. In the example shown in
Next, operation of the evaporator 10 will be described. When the compressor is operated, refrigerant decompressed by the expansion valve flows into the evaporator 10 from the refrigerant inlet portion 1. The refrigerant flowing into the refrigerant inlet portion 1 flows through the second tubes 5b in the first path from the first header tank 2a, and introduced into the second header tank 2b. The refrigerant flowing into the second header tank 2b from the second tubes 5b in the first path flows in the second header tank 2b from the left side to the right side in
According to the first embodiment, the tubes 5 are constructed of the plural first tubes 5a on the upstream air side and the plural second tubes 5b on the downstream air side. Furthermore, the first tube 5a and the second tube 5b are lined in the air flow direction to have a predetermined space therebetween in the air flow direction. The first tubes 5a and the second tubes 5b are connected to each other by the second fin part 4b without having a slit recessed from the ridge portions. Therefore, the strength for connecting the first and second tubes 5a, 5b can be increased thereby increasing the strength of the evaporator 10. As a result, the variation due to the refrigerant flow can be reduced, and noise can be effectively reduced.
Because the slits 18a, 18b, 19a, 19b opened and recessed from the ridge portions of the fin 4 in the tube stacking direction are provided at positions corresponding to the refrigerant passages of the tubes 5a, 5b in the air flow direction, condensed water generated on the evaporator 10 can be effectively drained downwardly through the slits 18a, 18b, 19a, 19b. Therefore, the amount of water flying into the compartment together with the air flow can be reduced.
In each fin 4, the first fin part 4a is connected to the second fin part 4b through the connection portion 18, and the second fin part 4b is connected to the third fin part 4c through the connection portion 19. Furthermore, the slits 18a, 18b, 19a, 19b are formed from the ridge portions of the wave-shaped fin 4. Therefore, heat transferring surface area can be increased in the fin 4, and heat exchanging performance of the evaporator 10 can be increased using the fin 4.
The second fin part 4b has a structure where a slit from the ridge portions is not provided. Furthermore, louvers are not provided partially in a middle area corresponding to the space portion between the first and second tubes 5a, 5b, where refrigerant does not flow. In this case, the strength of the core portion 13 can be further increased without reducing the heat exchanging performance. That is, the slits 18a, 18b, 19a, 19b are only provided in the fin 4 at positions corresponding to refrigerant flow areas in the air flow direction, where refrigerant flows in the tubes 5a, 5b.
In this embodiment, the fins 4 on both sides of the tubes 5a, 5b in the tube stacking direction are formed to have the same structure having the first to third fins 4a, 4b, 4c. However, the fins 4 on both sides of the tubes 5a, 5b may have different structures. For example, the positions of the slits 18a, 18b, 19a, 19b in the air flow direction can be suitably changed in the fins 4. Furthermore, the first and second tubes 5a, 5b may be partially connected in the air flow direction. Even in this case, by connecting the second fin 4b to both the first and second tubes 5a, 5b, the strength of the core portion 13 can be further increased.
Furthermore, in the first embodiment, any one of the slits 18a, 18b or the slits 19a, 19b may be provided in the fin 4 on the upstream air side or the downstream air side at a position other than the space portion between the first and second tubes 5a, 5b, in the air flow direction. In addition, the open shapes of the slits 18a, 18b and the slits 19a, 19b can be suitably changed.
The second embodiment of the present invention will be now described with reference to
The fin 22 fixed to the tubes 5a, 5b is provided in air flow direction as shown in
The fin 22 has first and second clearance portions 24, 25 each of which extends from one ridge portion of the wave-shaped fin 22 to another ridge portion of the wave-shaped fin 22 between adjacent tubes in the tube stacking direction. Therefore, the fin 22 is separated into a first fin part 22a, a second fin part 22b and a third fin part 22c by the first and second clearance portions 24, 25. The first clearance portion 24 is positioned in an area where the first tubes 5a are positioned in the air flow direction, and the second clearance portion 25 is positioned in an area where the second tubes 5b are positioned in the air flow direction. Therefore, the first and second tubes 5a, 5b are connected to each other in the air flow direction by the second fin part 22b. That is, the second fin part 22b functions as a bridge portion for connecting the first and second tubes 5a, 5b in the air flow direction. Therefore, the strength between the first and second tubes 5a, 5b can be increased, thereby increasing the strength of the core portion. Plural louvers are provided in the first to third fin parts 22a, 22b, 22c. The second fin part 22b may be not provided with the louvers at the portion corresponding to the space portion between the first and second tubes 5a, 5b, in the air flow direction. That is, the louvers may be not provided in the second fin part 22b in an area corresponding to the non-refrigerant flow portion between the first and second tubes 5a, 5b in the air flow direction. In this case, the strength between the first and second tubes 5a, 5b can be further increased.
The first clearance portion 24 can be provided at a position X1 in the air flow direction described in the first embodiment, and the second clearance portion 25 can be provided at a position X2 in the air flow direction described in the first embodiment. More specifically, the first clearance portion 24 can be provided at a position X1 where X1/D is in a range between 0.25 and 0.5 (0.25≦X1/D≦0.5). Accordingly, similarly to the first embodiment, the water draining performance can be effectively improved. Here, X1 is a position (distance) separated from the most upstream end of the fin 22 (core portion) in the air flow direction, and D is the entire dimension of the fin 22 (core portion) in the air flow direction. Furthermore, when the first clearance portion 24 is provided at a position X1 where X1/D is in a range between 0.25 and 0.35 (0.25≦X1/D≦0.35), the water draining performance can be more improved.
Furthermore, when the second clearance portion 25 can be provided at a position X2 where X2/D is in a range between 0.5 and 0.75 (0.5≦X2/D≦0.75), the water draining performance can be effectively improved on the downstream air side. Here, X2 is a position (distance) separated from the most upstream end of the fin 22 (core portion) in the air flow direction, and D is the entire dimension of the fin 22 (core portion) in the air flow direction. Furthermore, when the second clearance portion 25 is provided at a position X2 where X2/D is in a range between 0.65 and 0.75 (0.65≦X2/D≦0.75), the water draining performance on the downstream air side can be more improved.
According to the second embodiment, because the first and second clearance portions 24, 25 are provided, the water draining performance can improved thereby reducing the water flying amount together with the air flow. Furthermore, because each of the first tubes 5a and each of the second tubes 5b can be connected to each other by the second fin part 22b, the strength of the core portion can be increased, thereby reducing noise caused from the evaporator.
The third embodiment of the present invention will be now described with reference to
As shown in
In this embodiment, the first tube 5a and the second tube 5b are connected to each other in the air flow direction by the third fin part 26c that extends from the second tube 5b to the first tube 5a in the fir flow direction. That is, the third fin part 26c functions as a bridge portion for connecting the first tube 5a and the second tube 5b in the air flow direction. Therefore, the strength between the tubes 5a, 5b can be increased thereby increasing the strength of the core portion of the evaporator. Plural louvers are provided in the first to third fin parts 26a, 26b, 26c. The third fin part 26c may be not provided with the louvers at the portion corresponding to the space portion between the first and second tubes 5a, 5b in the air flow direction. That is, the louvers may be not provided in the third fin part 26c in an area corresponding to the non-refrigerant flow portion between the first and second tubes 5a, 5b in the air flow direction. In this case, the strength between the first and second tubes 5a, 5b can be increased.
The length of the first slit 27a from the ridge portion of the fin 26, connected to one first tube 5a, can be set different from the length of the first slit 27b from the ridge portion of the fin 26, connected to an adjacent first tube 5a adjacent to the one first tube 5a in the tube stacking direction. Similarly, the length of the second slit 28a from the ridge portion of the fin 26, connected to the one first tube 5a, can be set different from the length of the second slit 28b from the ridge portion of the fin 26, connected to the adjacent first tube 5a adjacent to the one first tube 5a.
According to the third embodiment, the plural slits 27a, 27b, 28a, 28b are provided in the fin 26 in an upstream area, where the first tubes 5a are provided, in the air flow direction. Accordingly, the water draining performance can be effectively increased, thereby reducing the water flying amount flying together with the air flow.
The fourth embodiment of the present invention will be now described with reference to
The tube structure of the fourth embodiment can be used for the second or third embodiment.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.
For example, in the above-described embodiments, the first tubes 5a on the upstream air side and the second tubes 5b on the downstream air side are formed separately from each other to have the space portion therebetween. However, as shown in
Alternatively, the inner space of the tube 5a, 5b may be not need to be separated into plural refrigerant passages. That is, a single refrigerant passage may be provided in each tube 5a, 5b.
In the above-described embodiments, two tubes (5a, 5b) are lined in the air flow direction; however, three or more tubes can be lined in the air flow direction. Furthermore, the length of the first tube 5a in the air flow direction can be made different to the length of the second tube 5b in the air flow direction. In addition, the slits or/and the clearance portions can be provided at plural positions more than two in the air flow direction.
In the above-described embodiments, the present invention is typically used for an evaporator of the refrigerant cycle device. However, the present invention can be used for a heat exchanger for other use, on which condensed water is generated when performing heat exchange.
Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.
Number | Date | Country | Kind |
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2005-303660 | Oct 2005 | JP | national |