JP6613996B2 - Refrigerant evaporator - Google Patents

Description

  The present invention relates to a refrigerant evaporator that exchanges heat between a fluid to be cooled and a refrigerant.

  The refrigerant evaporator functions as a cooling heat exchanger that cools the cooled fluid by absorbing heat from the cooled fluid (for example, air) and evaporating the liquid-phase refrigerant. The refrigerant evaporator is applied to a refrigeration cycle or the like mounted on a vehicle air conditioner.

  As this type of refrigerant evaporator, one described in Patent Document 1 is known. The refrigerant evaporator described in Patent Document 1 includes first to fourth core portions. In the flow direction of the fluid to be cooled, the first core portion and the third core portion overlap each other, and the second core portion and the fourth core portion overlap each other.

  An intermediate tank portion is disposed between the first and second core portions and the third and fourth core portions. The intermediate tank part is formed with a first passage that guides the refrigerant that has passed through the first core part to the fourth core part, and a second passage that guides the refrigerant that has passed through the second core part to the third core part. ing. The invention described in Patent Document 1 suppresses the distribution of the refrigerant from becoming uneven by supplying the refrigerant to the first to fourth core portions in this way.

JP 2013-185723 A

  Incidentally, lubricating oil is used in a compressor that pumps refrigerant in a refrigeration cycle for smooth driving. This lubricating oil may be mixed in the refrigerant as the compressor is driven. If the lubricating oil stays in the piping, refrigerant evaporator, or the like constituting the refrigeration cycle, the compressor may become poorly lubricated and hinder driving. For this reason, each device constituting the refrigeration cycle is required to have a design in which the lubricating oil is discharged to the downstream side together with the refrigerant and returned to the compressor.

  On the other hand, in the refrigerant evaporator described in Patent Document 1, the refrigerant supplied from the expansion valve or the like of the refrigeration cycle is distributed to the first core portion and the second core portion, and the distributed refrigerant does not merge. The 3 core part and the 4th core part are comprised so that it may flow. Therefore, the flow rate of the refrigerant flowing through each of the first to fourth core parts and the intermediate tank part as compared with other refrigerant evaporators configured to sequentially pass through the plurality of core parts without being distributed. Tends to be smaller. As a result, the refrigerant evaporator described in Patent Document 1 has a problem that the lubricating oil cannot be discharged together with the refrigerant.

  This invention is made | formed in view of such a subject, The objective is to provide the refrigerant evaporator which can suppress the retention of lubricating oil.

In order to solve the above problems, a refrigerant evaporator according to the present invention is a refrigerant evaporator (1, 1A) that performs heat exchange between a fluid to be cooled and a refrigerant, and a part of the fluid to be cooled. A first core part (21a) that exchanges heat with a part of the refrigerant, and a second core part that exchanges heat between the other part of the fluid to be cooled and the other part of the refrigerant (21b) and a third core portion (overflowing with the first core portion in the flow direction of the fluid to be cooled) for exchanging heat between a portion of the fluid to be cooled and the other portion of the refrigerant ( 11a) and a fourth core portion (11b) that is arranged so as to overlap with the second core portion in the flow direction of the fluid to be cooled and allows heat exchange between the other portion of the fluid to be cooled and a portion of the refrigerant. ) And a refrigerant inlet (22a) in the vicinity of the first core portion, and a plurality of tubes (21c) constituting the first core portion and the second core portion. A distribution tank portion (22) that is provided at the flow end and distributes the refrigerant to the tubes and a downstream end of the plurality of tubes (21c) that constitute the first core portion and collects the refrigerant that has passed through the tubes. A first collecting portion (23a), a second collecting portion (23b) that is provided at the downstream end of the plurality of tubes (21c) constituting the second core portion and collects the refrigerant that has passed through the tubes, and a third core Provided at the upstream ends of the plurality of tubes (11c) constituting the portion, and at the upstream ends of the first distribution portion (13a) for distributing the refrigerant to the tubes and the plurality of tubes (11c) constituting the fourth core portion. A second distribution portion (13b) that distributes the refrigerant to the tube, a first passage (33a) that communicates the first collection portion and the second distribution portion, and a second collection portion and a first distribution portion. The second passage (33b) communicating with the It has been provided with the intermediate tank unit (33). The volume of the second passage is smaller than the volume of the first passage. The intermediate tank portion includes a partition member (34) that partitions the first passage and the second passage. The partition member is formed with a communication hole (34d) for communicating the first passage and the second passage. The communication hole is formed at the bottom of the partition member. The first passage is formed so that the refrigerant flows along the bottom of the partition member, and is formed so that the cross-sectional area increases from the portion connected to the communication hole to the downstream side.

  According to the said structure, a refrigerant | coolant is distributed from the distribution tank part to the tube which each comprises a 1st core part and a 2nd core part. The distribution tank portion has a refrigerant inlet in the vicinity of the first core portion. In such a configuration, since the refrigerant is easily supplied to the first core portion near the refrigerant inlet, the flow rate of the distributed refrigerant is relatively small in the second core portion far from the refrigerant inlet.

  In the above configuration, the refrigerant that has passed through the first core portion is guided to the fourth core portion by the first passage, and the refrigerant that has passed through the second core portion is guided to the third core portion by the second passage. The volume of the second passage is smaller than the volume of the first passage. That is, the refrigerant that passes through the second core part and has a relatively small flow rate is supplied to the second passage having a relatively small volume. By supplying the refrigerant having a relatively small flow rate and the possibility that the lubricating oil may stay in the second passage, even when the lubricating oil stays, it is possible to suppress the staying amount.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigerant evaporator which can suppress the retention of lubricating oil can be provided.

It is a perspective view which shows the refrigerant evaporator which concerns on 1st Embodiment. It is a disassembled perspective view which shows the refrigerant evaporator of FIG. It is a perspective view which shows the partition member of FIG. It is a disassembled perspective view which shows the flow of the refrigerant | coolant in the refrigerant evaporator of FIG. It is sectional drawing which shows the flow model of the refrigerant | coolant seen along the Y direction of FIG. It is sectional drawing which shows the flow model of the refrigerant | coolant which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  The refrigerant evaporator 1 according to the first embodiment is a heat exchanger applied to a refrigeration cycle of a vehicle air conditioner. Specifically, the refrigerant evaporator 1 is a cooling heat exchanger that cools the air by absorbing heat from the air blown into the passenger compartment and evaporating the liquid-phase refrigerant. As is well known, the refrigeration cycle includes a compressor, a radiator, an expansion valve, etc. (not shown) in addition to the refrigerant evaporator 1.

  First, the configuration of the refrigerant evaporator 1 will be described with reference to FIGS. 1 to 5. The refrigerant evaporator 1 includes an upwind evaporator 10, a downwind evaporator 20, and an intermediate tank 33.

  The windward evaporator 10 includes a windward core part 11, a windward distribution tank part 13, and a windward collecting tank part 12.

  As shown in FIG. 1, the windward core portion 11 is configured by a stacked body in which a plurality of tubes 11 c and a plurality of fins 11 d are alternately stacked in the horizontal direction. The tube 11c has a flat cross section and extends in the vertical direction, and a flow path for flowing the refrigerant is formed inside. The fin 11d is a corrugated fin, and is formed by bending a thin metal plate. The fin 11d is disposed between the adjacent tubes 11c, and is joined to a flat surface among the outer surfaces of the tubes 11c. In addition, side plates 11e are disposed at both ends of the stacking direction (hereinafter, this direction is also simply referred to as “stacking direction”) of the stack composed of the plurality of tubes 11c and the plurality of fins 11d, and the windward core The part 11 is reinforced. 2 and 4, the illustration of the tubes 11c, the fins 11d, and the side plates 11e that constitute the windward core portion 11 is omitted.

  As shown in FIG. 2, the windward core portion 11 includes a third core portion 11a and a fourth core portion 11b. The third core portion 11a is a part of the plurality of tubes 11c, and is configured by a group of tubes 11c arranged to form one row. The 4th core part 11b is comprised by the group of the tubes 11c arranged so that the remainder of the some tube 11c might comprise one row. The 3rd core part 11a and the 4th core part 11b are arrange | positioned so that it may adjoin in the lamination direction. When the refrigerant evaporator 1 is viewed along the X direction, which is the direction in which air flows, the third core portion 11a is configured by a tube group disposed on the right side in the stacking direction, and the fourth core portion 11b is in the stacking direction. It consists of a group of tubes arranged on the left side. That is, part of the air flowing in the X direction passes through the third core part 11a, and the other part passes through the fourth core part. Each of the third core portion 11a and the fourth core portion 11b has a wide shape in which the dimension in the stacking direction is larger than the dimension in the X direction.

  The windward distribution tank unit 13 is disposed below the windward core unit 11. The windward distribution tank unit 13 is a cylindrical body whose both ends are closed, and a flow path through which a refrigerant flows is formed inside. A plurality of through holes (not shown) are formed in the upper part of the windward distribution tank unit 13. Lower end portions of a plurality of tubes 11c constituting the windward core portion 11 are inserted into and joined to the through holes. That is, the windward distribution tank unit 13 is configured such that the flow path inside thereof communicates with the plurality of tubes 11 c of the windward core unit 11. Thereby, the windward distribution tank unit 13 functions as a distribution unit for distributing the refrigerant to the plurality of tubes 11 c constituting the windward core unit 11.

  As shown in FIGS. 2 and 4, a partition plate 13 c is disposed inside the upwind distribution tank unit 13 and at a central position in the longitudinal direction. The partition plate 13c partitions the internal flow path of the windward distribution tank unit 13 into a first distribution unit 13a and a second distribution unit 13b. The 1st distribution part 13a is the space connected to the some tube 11c which comprises the 3rd core part 11a. The 1st distribution part 13a distributes a refrigerant | coolant to the some tube 11c which comprises the 3rd core part 11a. The second distribution unit 13b is a space that communicates with the plurality of tubes 11c constituting the fourth core unit 11b. The 2nd distribution part 13b distributes a refrigerant | coolant to the some tube 11c which comprises the 4th core part 11b. A first distribution unit communication port 131 and a second distribution unit communication port 132 are formed on the side surface of the windward distribution tank unit 13 on the intermediate tank unit 33 side. The 1st distribution part communication port 131 penetrates the pipe wall of the windward distribution tank part 13, and connects the inside and outside of the 1st distribution part 13a. The 2nd distribution part communication port 132 penetrates the pipe wall of the windward distribution tank part 13, and connects the inside and outside of the 2nd distribution part 13b.

  The windward collecting tank 12 is disposed above the windward core 11. The windward collecting tank portion 12 is a cylindrical body, and a flow path through which the refrigerant flows is formed inside. When viewed along the X direction, the windward side collecting tank portion 12 is closed at the left end and formed with a refrigerant outlet 12a at the right end. The refrigerant outlet 12a leads the refrigerant from the inside of the windward collecting tank portion 12 to the suction side of a compressor (not shown). A plurality of through holes (not shown) are formed at the bottom of the windward collecting tank 12. Upper end portions of a plurality of tubes 11c constituting the windward core portion 11 are inserted and joined to the through holes. In other words, the windward collecting tank portion 12 is configured such that the flow path inside thereof communicates with the plurality of tubes 11 c of the windward core portion 11. Thereby, the windward collecting tank unit 12 functions as a collecting unit for collecting the refrigerant that has flowed out from the plurality of tubes 11 c of the windward core unit 11.

  The leeward evaporator 20 is arranged so as to overlap with the leeward evaporator 10 when viewed along the X direction. The leeward side evaporation unit 20 includes a leeward side core portion 21, a leeward side distribution tank portion 22, and a leeward side collecting tank portion 23.

  As shown in FIG. 1, the leeward core portion 21 is configured by a stacked body in which a plurality of tubes 21 c and a plurality of fins 21 d are alternately stacked in the horizontal direction. The tube 21c has a flat cross section and extends in the vertical direction, and a flow path for flowing the refrigerant is formed inside. The fins 21d are corrugated fins and are formed by bending a thin metal plate. The fins 21d are disposed between the adjacent tubes 21c, and are joined to a flat surface among the outer surfaces of the tubes 21c. In addition, side plates 21e are arranged at both ends in the stacking direction of the stacked body composed of the plurality of tubes 21c and the plurality of fins 21d to reinforce the leeward core portion 21. 2 and 4, illustration of the tubes 21c, the fins 21d, and the side plates 21e constituting the leeward core portion 21 is omitted.

  As shown in FIG. 2, the leeward core portion 21 includes a first core portion 21 a and a second core portion 21 b. The first core portion 21a is a part of the plurality of tubes 21c, and is configured by a group of tubes 21c arranged so as to form one row. The second core portion 21b is a remaining portion of the plurality of tubes 21c, and is configured by a group of tubes 21c arranged so as to form one row. The 1st core part 21a and the 2nd core part 21b are arrange | positioned so that it may adjoin in the lamination direction. When the refrigerant evaporator 1 is viewed along the X direction in which air flows, the first core portion 21a is configured by a tube group disposed on the right side in the stacking direction, and the second core portion 21b is disposed on the left side in the stacking direction. It is comprised by the tube group made. Further, when the refrigerant evaporator 1 is viewed along the X direction, the first core portion 21a is disposed so as to overlap with the third core portion 11a, and the second core portion 21b is disposed so as to overlap with the fourth core portion 11b. ing. As a result, the air flowing in the X direction passes through the first core portion 21a after part of the air passes through the third core portion 11a, while the second part passes through the fourth core portion 11b. It passes through the core part 21b. Each of the first core portion 21a and the second core portion 21b has a wide shape in which the dimension in the stacking direction is larger than the dimension in the X direction.

  The leeward distribution tank unit 22 is disposed above the leeward core unit 21. The leeward side distribution tank unit 22 is a cylindrical body, and a flow path through which the refrigerant flows is formed inside. When viewed along the X direction, the leeward side distribution tank section 22 is closed at the left end and formed with a refrigerant inlet 22a at the right end. The refrigerant inlet 22a introduces a low-pressure refrigerant decompressed by an unillustrated expansion valve. A plurality of through holes (not shown) are formed at the bottom of the leeward distribution tank unit 22. Upper end portions of a plurality of tubes 21c constituting the leeward core portion 21 are inserted and joined to the through holes. That is, the leeward distribution tank unit 22 is configured such that the flow path inside thereof communicates with the plurality of tubes 21 c of the leeward core unit 21. Thereby, the leeward side distribution tank part 22 functions as a distribution part for distributing the refrigerant to the plurality of tubes 21 c constituting the leeward side core part 21.

  The leeward side collecting tank portion 23 is disposed below the leeward side core portion 21. The leeward side collecting tank portion 23 is a cylindrical body whose both ends are closed, and a flow path through which a refrigerant flows is formed inside. A plurality of through holes (not shown) are formed in the upper part of the leeward side collecting tank portion 23. Lower end portions of a plurality of tubes 21c constituting the leeward side core portion 21 are inserted into and joined to the through holes. That is, the leeward side collective tank portion 23 is configured such that the flow path inside thereof communicates with the plurality of tubes 21c.

  A partition plate 23c is arranged inside the leeward side collecting tank portion 23 and at the center position in the longitudinal direction. The partition plate 23c divides the internal flow path of the leeward side collecting tank portion 23 into a first collecting portion 23a and a second collecting portion 23b. The first collecting portion 23a is a space communicating with the plurality of tubes 21c constituting the first core portion 21a. The 1st gathering part 23a collects the refrigerant which flowed out from a plurality of tubes 21c which constitute the 1st core part 21a. The second collecting portion 23b is a space communicating with the plurality of tubes 21c constituting the second core portion 21b. The second collecting portion 23b collects the refrigerant that has flowed out of the plurality of tubes 21c constituting the second core portion 21b. That is, the leeward side collecting tank portion 23 functions as a collecting portion that separately collects the refrigerant flowing out from the first core portion 21a and the refrigerant flowing out from the second core portion 21b.

  A first collecting portion communication port 231 and a second collecting portion communication port 232 are formed on the side surface of the leeward collecting tank portion 23 on the intermediate tank portion 33 side. The first collecting portion communication port 231 passes through the tube wall of the leeward collecting tank portion 23 and communicates the inside and outside of the first collecting portion 23a. Further, the second collecting portion communication port 232 penetrates the tube wall of the leeward collecting tank portion 23 and communicates the inside and outside of the second collecting portion 23b.

  The intermediate tank unit 33 is provided between the windward distribution tank unit 13 of the windward evaporator 10 and the leeward collective tank unit 23 of the leeward evaporator 20. The intermediate tank part 33 is a cylindrical body in which a flow path through which a refrigerant flows is formed.

  As shown in FIGS. 2 and 4, a partition member 34 is provided inside the intermediate tank portion 33. As shown in FIG. 3, the partition member 34 includes a plate-like side plate 34a, a bottom plate 34b, and an inclined plate 34c each having a predetermined thickness. The side plate 34 a is curved so that one end thereof is along the inner wall surface of the intermediate tank portion 33. The bottom plate 34b extends from the other end of the side plate 34a in a direction substantially perpendicular to the side plate 34a. The inclined plate 34c extends from the end of the bottom plate 34b in a direction inclined with respect to the bottom plate 34b. The inclined plate 34c is formed such that the width dimension thereof becomes smaller as the distance from the end of the bottom plate 34b increases. A communication hole 34d is formed in a part of the bottom plate 34b near the inclined plate 34c. The communication hole 34d penetrates the bottom plate 34b in the thickness direction.

  The partition member 34 is provided in a portion near the upper part in the intermediate tank portion 33. The intermediate tank 33 is partitioned into a first passage 33 a and a second passage 33 b by the partition member 34.

  As shown in FIG. 5, the first passage 33 a is a portion formed around the second passage 33 b in the space in the intermediate tank portion 33. The first passage 33a has a throttle channel 33k. The throttle channel 33k is formed in the lower part of the intermediate tank part 33 by a partition member 33c provided in the upper part of the intermediate tank part 33. An end channel 33m is formed on the upstream side of the throttle channel 33k, and an end channel 33n is formed on the downstream side. The end channels 33m and 33n have a channel cross-sectional area larger than that of the throttle channel 33k.

  As shown in FIG. 5, the second passage 33 b is a space surrounded by the upper pipe wall of the intermediate tank portion 33 and the side plate 34 a, the bottom plate 34 b, and the inclined plate 34 c of the partition member 34. The volume of the second passage 33b is smaller than the volume of the first passage 33a.

  As shown in FIGS. 2 and 4, a first communication port 331 and a second communication port 332 are formed on the side surface of the intermediate tank unit 33 on the leeward side collecting tank unit 23 side. The first communication port 331 penetrates the tube wall of the intermediate tank portion 33 and communicates the inside and the outside of the first passage 33a. The second communication port 332 passes through the tube wall of the intermediate tank 33 and communicates with the inside and outside of the second passage 33b.

  In addition, a third communication port 333 and a fourth communication port 334 are formed on the side surface of the intermediate tank unit 33 on the windward distribution tank unit 13 side. The third communication port 333 penetrates the tube wall of the intermediate tank portion 33 and communicates the inside and the outside of the first passage 33a. The fourth communication port 334 passes through the tube wall of the intermediate tank 33 and communicates with the inside and outside of the second passage 33b.

  Next, the flow of the refrigerant in the refrigerant evaporator 1 and the cooling of the air thereby will be described with reference to FIGS. 4 and 5.

  The low-pressure refrigerant decompressed by an expansion valve (not shown) is supplied to the refrigerant evaporator 1 in a liquid phase state. As shown by an arrow A in FIG. 4, the refrigerant is introduced into the leeward distribution tank unit 22 from the refrigerant inlet 22a. This refrigerant is distributed inside the leeward side distribution tank part 22 and flows into the first core part 21a and the second core part 21b of the leeward side core part 21 as indicated by arrows B and C.

  The refrigerant that has flowed into the first core portion 21a and the second core portion 21b flows downward in the plurality of tubes 11c that constitute each of the refrigerants. At this time, the refrigerant flowing inside the plurality of tubes 11c exchanges heat with air passing between the plurality of tubes 11c in the X direction. As a result, part of the liquid-phase refrigerant evaporates and absorbs heat from the air, thereby cooling the air.

  The refrigerant flowing out from the lower end portion of the first core portion 21a flows into the first collecting portion 23a of the leeward collecting tank portion 23 and is collected as indicated by an arrow D. Further, the refrigerant flowing out from the lower end portion of the second core portion 21 b flows into the second collecting portion 23 b of the leeward collecting tank portion 23 and is collected as indicated by an arrow E.

  The refrigerant collected in the first collecting portion 23a is discharged from the first collecting portion 23a through the first collecting portion communication port 231 as indicated by an arrow F. This refrigerant flows into the end channel 33m of the first passage 33a through the first communication port 331. Further, the refrigerant collected in the second collecting portion 23b is discharged from the second collecting portion 23b through the second collecting portion communication port 232 as indicated by an arrow G. This refrigerant flows into the second passage 33b through the second communication port 332.

  As shown by the arrow C1 in FIG. 5, the refrigerant flowing into the end channel 33m of the first passage 33a flows into the throttle channel 33k so as to wrap around the second passage 33b. Since the throttle channel 33k has a smaller channel cross-sectional area than the end channel 33m, the flow rate of the refrigerant flowing into the throttle channel 33k increases. The refrigerant that has flowed through the throttle channel 33k at high speed flows into the end channel 33n on the downstream side. As indicated by an arrow C2 in FIG. 5, the refrigerant changes the flow direction along the wall surface 33p of the intermediate tank 33, and flows toward the third communication port 333 shown in FIG.

  The refrigerant that has passed through the first passage 33a of the intermediate tank portion 33 is discharged from the second passage 33b through the third communication port 333 as indicated by an arrow H in FIG. The refrigerant flows toward the windward distribution tank unit 13 and flows into the second distribution unit 13b through the second distribution unit communication port 132.

  On the other hand, the refrigerant that has passed through the second passage 33b of the intermediate tank portion 33 is discharged from the second passage 33b through the fourth communication port 334 as indicated by an arrow I in FIG. The refrigerant flows toward the windward distribution tank unit 13 and flows into the first distribution unit 13a through the first distribution unit communication port 131.

  The refrigerant that has flowed into the first distribution portion 13a flows from the lower end portion of the third core portion 11a as indicated by an arrow K in FIG. Specifically, the refrigerant in the first distribution unit 13a is distributed to the plurality of tubes 11c that constitute the third core unit 11a.

  The refrigerant that has flowed into the second distribution portion 13b flows from the lower end portion of the fourth core portion 11b, as indicated by an arrow J in FIG. Specifically, the refrigerant in the second distribution unit 13b is distributed to the plurality of tubes 11c that constitute the fourth core unit 11b.

  The refrigerant that has flowed into the third core portion 11a and the fourth core portion 11b flows upward in the plurality of tubes 11c constituting each of them. At this time, the refrigerant flowing inside the plurality of tubes 11c exchanges heat with air passing between the plurality of tubes 11c in the X direction. As a result, part of the liquid-phase refrigerant evaporates and absorbs heat from the air, thereby cooling the air.

  As shown by the arrows M and L in FIG. 4, the refrigerant that has flowed out from the upper ends of the third core portion 11 a and the fourth core portion 11 b flows into and merges with the inside of the windward collecting tank portion 12. . As indicated by an arrow N in FIG. 4, this refrigerant flows through the inside of the windward collecting tank unit 12 and flows out of the refrigerant evaporator 1 from the refrigerant outlet 12a. Thereafter, the refrigerant is supplied to the suction side of a compressor (not shown).

  In the configuration in which the refrigerant flows into the leeward distribution tank unit 22 from the refrigerant inlet 22a in the vicinity of the first core unit 21a, a difference occurs in the flow rate of the refrigerant distributed to the first core unit 21a and the second core unit 21b. . That is, there is a tendency that a refrigerant having a larger flow rate is supplied to the first core portion 21a that is close to the refrigerant inlet 22a and into which the refrigerant easily flows, as compared to the second core portion 21b that is far from the refrigerant inlet 22a.

  When such a difference in the flow rate of the refrigerant occurs, the air passing through the first core portion 21a actively exchanges heat with the refrigerant as compared with the air passing through the second core portion 21b. For this reason, there is a possibility that the temperature distribution is biased in the air passing in the X direction.

  Therefore, the refrigerant evaporator 1 is configured so that the refrigerant from the leeward side collective tank unit 23 toward the upwind distribution tank unit 13 intersects the X direction as described above. That is, the refrigerant in the first collecting portion 23 a of the leeward collecting tank portion 23 is guided to the second distributing portion 13 b of the leeward distributing tank portion 13 through the intermediate tank portion 33. Further, the refrigerant in the second collecting portion 23 b of the leeward collecting tank portion 23 is guided to the first distributing portion 13 a of the leeward distributing tank portion 13 through the intermediate tank portion 33.

  Thus, by replacing the refrigerant so as to intersect the X direction, the flow rate of the refrigerant in which a part of the air passing through the first core portion 21a and the third core portion 11a exchanges heat, and the second core It becomes possible to reduce the difference between the flow rate of the refrigerant that exchanges heat with the other part of the air passing through the portion 21b and the fourth core portion 11b. As a result, it is possible to suppress an uneven temperature distribution in the air passing in the X direction.

  Incidentally, lubricating oil is used in a compressor that pumps refrigerant in a refrigeration cycle for smooth driving. This lubricating oil may be mixed in the refrigerant as the compressor is driven. If the lubricating oil stays in the piping, refrigerant evaporator, or the like constituting the refrigeration cycle, the compressor may become poorly lubricated and hinder driving.

  Such stagnation of the lubricating oil appears remarkably in a path where the flow rate of the refrigerant is small. That is, in the second core portion 21b in which the flow rate of the refrigerant supplied is smaller than that of the first core portion 21a and the path in which the refrigerant is supplied from the second core portion 21b, the lubricating oil cannot be discharged downstream together with the refrigerant. There are concerns.

  In the refrigerant evaporator 1, a device is devised in the intermediate tank portion 33 in order to solve such a problem. Next, this device will be described with reference to FIG.

  As described above, the refrigerant that has passed through the first core portion 21 a is supplied to the first passage 33 a of the intermediate tank portion 33 through the first collecting portion 23 a of the leeward side collecting tank portion 23. On the other hand, the refrigerant that has passed through the second core portion 21 b is supplied to the second passage 33 b of the intermediate tank portion 33 through the second collecting portion 23 b of the leeward side collecting tank portion 23. That is, among the refrigerants distributed in the leeward side distribution tank unit 22, a refrigerant having a relatively large flow rate is supplied to the first passage 33a, whereas a refrigerant having a relatively small flow rate is supplied to the second passage 33b. The

  For this reason, as shown in FIG. 5, the second passage 33b retains the lubricating oil LO mixed in the refrigerant. The lubricating oil LO stays on the bottom plate 34b of the partition member 34 with both ends surrounded by the side plates 34a and the inclined plates 34c. However, since the volume of the second passage 33b is smaller than the volume of the first passage 33a as described above, the retention amount of the lubricating oil LO is small.

  As described above, the communication plate 34 d is formed in the bottom plate 34 b of the partition member 34. The communication hole 34d communicates the throttle channel 33k of the first passage 33a and the second passage 33b. Therefore, the lubricating oil LO is discharged from the second passage 33b through the communication hole 34d by its own weight, and flows into the lower throttle passage 33k.

  Further, the throttle channel 33k of the first passage 33a is formed to flow the refrigerant along the bottom plate 34b below the partition member 34. The communication hole 34d faces the throttle channel 33k. As described above, since the cross-sectional area of the throttle channel 33k is smaller than that of the end channel 33m, the flow rate of the refrigerant flowing through the throttle channel 33k is large as indicated by the arrow C1. For this reason, the lubricating oil LO staying in the second passage 33b is attracted by the refrigerant flow having a high flow velocity through the communication hole 34d. As a result, the discharge of the lubricating oil LO is promoted through the communication hole 34d.

  The end channel 33n of the first passage 33a has a cross-sectional area that increases from the vicinity of the communication hole 34d to the downstream side thereof. That is, the distance between the wall surface of the intermediate tank portion 33 and the inclined plate 34c of the partition member 34 gradually increases from the vicinity of the communication hole 34d to the downstream side thereof. When the cross-sectional area is enlarged in the end flow path 33n in this way, the flow rate of the refrigerant flowing therethrough is reduced and the pressure is increased. For this reason, the refrigerant flow is disturbed in the vicinity of the communication hole 34d, for example, a part of the refrigerant in the end flow path 33n flows backward. As a result, the discharge of the lubricating oil LO is promoted through the communication hole 34d.

  As described above, the lubricating oil LO is actively discharged from the second passage 33b through the communication hole 34d due to its own weight, attraction by the refrigerant flowing through the throttle channel 33k, disturbance of the refrigerant flow in the end channel 33n, and the like. Is done. The lubricating oil LO is discharged from the refrigerant evaporator 1 together with the flowing refrigerant as indicated by arrows C1 and C2, and is supplied to a compressor provided on the downstream side. Thereby, it is suppressed that a compressor becomes poor lubrication.

  As described above, according to the configuration of the refrigerant evaporator 1, the refrigerant is distributed from the leeward side distribution tank portion 22 to the tubes 21c constituting the first core portion 21a and the second core portion 21b. The leeward distribution tank section 22 has a refrigerant inlet 22a in the vicinity of the first core section 21a. In such a configuration, since the refrigerant is easily supplied to the first core portion 21a close to the refrigerant inlet 22a, the flow rate of the distributed refrigerant is relatively small in the second core portion 21b far from the refrigerant inlet 22a.

  In the above configuration, the refrigerant that has passed through the first core portion 21a is guided to the fourth core portion 11b by the first passage 33a, and the refrigerant that has passed through the second core portion 21b is guided by the second passage 33b to the third core portion 11a. Lead to. The volume of the second passage 33b is smaller than the volume of the first passage 33a. That is, the flow of the refrigerant passing through the second core portion 21b and having a relatively small flow rate is supplied to the second passage 33b having a relatively small volume. By supplying the flow of the refrigerant having a relatively small flow rate and the possibility that the lubricating oil LO may be retained to the second passage 33b, even when the lubricating oil LO is retained, the amount of the retained oil can be suppressed. .

  Moreover, the intermediate tank part 33 has the partition member 34 which divides the 1st channel | path 33a and the 2nd channel | path 33b inside. The partition member 34 is formed with a communication hole 34d for communicating the first passage 33a and the second passage 33b. According to this configuration, when the lubricating oil LO stays in the second passage 33b, the lubricating oil LO can be discharged to the first passage 33a through the communication hole 34d. As a result, the lubricating oil LO can be discharged to the downstream side of the refrigerant evaporator 1 together with the refrigerant flow having a large flow rate in the first passage 33a, and returned to the compressor.

  Further, the communication hole 34 d is formed on the bottom surface of the partition member 34. According to this configuration, even when the lubricating oil LO stays in the second passage 33b, the lubricating oil LO is discharged from the second passage 33b through the communication hole 34d formed in the bottom plate 34b by its own weight. Is possible.

  Further, the first passage 33 a is formed so that the refrigerant flows along the bottom surface of the partition member 34. According to this configuration, the lubricating oil LO staying in the second passage 33b is attracted by the refrigerant flowing through the first passage 33a. As a result, it becomes possible to promote the discharge of the lubricating oil LO through the communication hole 34d.

  The first passage 33a is formed so that the cross-sectional area increases from the vicinity of the communication hole 34d to the downstream side thereof. According to this configuration, the flow rate of the refrigerant flowing through the portion where the cross-sectional area of the first passage 33a is increased is decreased, and the pressure is increased. For this reason, the refrigerant flow is disturbed in the vicinity of the communication hole 34d, for example, a part of the refrigerant flows backward. As a result, it becomes possible to promote the discharge of the lubricating oil LO through the communication hole 34d.

  Next, the refrigerant evaporator 1A according to the second embodiment will be described with reference to FIG. This refrigerant evaporator 1A is applied to the refrigeration cycle of a vehicle air conditioner that adjusts the temperature in the passenger compartment, as in the first embodiment. The refrigerant evaporator 1A is different from the partition member 34 according to the first embodiment in the shape of the partition member 34A. In the refrigerant evaporator 1A, the same components as those of the refrigerant evaporator 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 6 shows the periphery of the partition member 34A of the refrigerant evaporator 1A according to the second embodiment. FIG. 6 shows the refrigerant evaporator 1A from the direction corresponding to FIG.

  The partition member 34A is formed with a protruding cylinder 34e protruding upward at a part of its bottom plate 34b. The protruding cylinder 34e has a cylindrical shape and is closed at its upper end.

  A plurality of communication holes 34d1 are formed on the side surface of the protruding cylinder 34e and in the vicinity of the bottom plate 34b. The communication hole 34d1 penetrates the protruding cylinder 34e and communicates the inside and the outside.

  Even in the refrigerant evaporator 1A according to the second embodiment configured as described above, even when the lubricating oil LO stays in the second passage 33b, the lubricating oil LO can be discharged through the communication hole 34d1. become. The discharge of the lubricating oil LO is prompted by the attraction of the refrigerant flowing through the throttle channel 33k as indicated by the arrow C3. Further, by providing a plurality of communication holes 34d1, it is possible to further promote the discharge of the lubricating oil LO.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. Each element provided in each of the specific examples described above and its arrangement, material, condition, shape, size, and the like are not limited to those illustrated, but can be changed as appropriate.

1, 1A: Refrigerant evaporator 11a: 3rd core part 11b: 4th core part 11c: Tube 13a: 1st distribution part 13b: 2nd distribution part 21a: 1st core part 21b: 2nd core part 21c: Tube 22 : Downward distribution tank section (distribution tank section)
22a: Refrigerant inlet 23a: first collecting portion 23b: second collecting portion 33: intermediate tank portion 33a: first passage 33b: second passage 34, 34A: partition members 34d, 34d1: communication hole

Claims (1)

A refrigerant evaporator (1, 1A) that exchanges heat between a fluid to be cooled and a refrigerant,
A first core portion (21a) that exchanges heat between a part of the fluid to be cooled and a part of the refrigerant;
A second core portion (21b) that performs heat exchange between the other part of the fluid to be cooled and the other part of the refrigerant;
A third core portion (11a) which is arranged so as to overlap the first core portion in the flow direction of the fluid to be cooled and allows heat exchange between a part of the fluid to be cooled and another portion of the refrigerant. When,
A fourth core portion (11b) that is arranged so as to overlap with the second core portion in the flow direction of the fluid to be cooled and allows heat exchange between another portion of the fluid to be cooled and a portion of the refrigerant. When,
A refrigerant inlet (22a) is provided in the vicinity of the first core part, provided at the upstream ends of a plurality of tubes (21c) constituting the first core part and the second core part, and the refrigerant is supplied to the tubes. A distribution tank section (22) for distribution;
A first collecting portion (23a) that is provided at a downstream end of the plurality of tubes (21c) constituting the first core portion and collects the refrigerant that has passed through the tubes;
A second collecting portion (23b) that is provided at a downstream end of the plurality of tubes (21c) constituting the second core portion and collects the refrigerant that has passed through the tubes;
A first distribution part (13a) that is provided at an upstream end of the plurality of tubes (11c) constituting the third core part and distributes the refrigerant to the tubes;
A second distribution part (13b) provided at the upstream end of the plurality of tubes (11c) constituting the fourth core part and distributing the refrigerant to the tubes;
A first passage (33a) that connects the first collecting portion and the second distributing portion and a second passage (33b) that connects the second collecting portion and the first distributing portion are formed inside. Intermediate tank portion (33),
Volume of the second passage, rather smaller than the volume of the first passage,
The intermediate tank portion has a partition member (34) that partitions the first passage and the second passage inside,
The partition member is formed with a communication hole (34d) for communicating the first passage and the second passage,
The communication hole is formed at the bottom of the partition member,
The first passage is formed so that the refrigerant flows along the bottom of the partition member, and the refrigerant evaporator is formed so that a cross-sectional area increases from a portion connected to the communication hole to a downstream side . .

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