JP6002583B2 - Evaporator - Google Patents

Description

  The present invention relates to an evaporator suitably used for a car air conditioner that is a refrigeration cycle mounted on an automobile.

  In this specification and the claims, the top and bottom of FIGS. 1 and 3 are the top and bottom.

  As an evaporator used in a car air conditioner, the present applicant has previously arranged 1 in the vertical direction with the longitudinal direction oriented in a direction perpendicular to two directions of the vertical direction and the ventilation direction. A pair of header tanks and a plurality of flat refrigerant flow pipes arranged with the longitudinal direction between the upper and lower header tanks in the vertical direction and the width direction in the ventilation direction are provided in each header tank. A leeward header portion and an leeward header portion whose direction is directed in the longitudinal direction of the header tank are provided side by side in the ventilation direction, and a refrigerant inlet is provided at one end of the leeward header portion of one header tank. A plurality of pipe sets comprising two flat refrigerant flow pipes provided with a refrigerant outlet at the same end as the refrigerant inlet in the upper header portion and arranged at intervals in the ventilation direction are formed as a header tank. Are arranged in parallel at intervals in the longitudinal direction, ventilation gaps are formed between adjacent pipe sets, and corrugated fins are arranged in all ventilation gaps so as to straddle both refrigerant flow pipes of the pipe sets. The corrugated fin includes a wave crest extending in the ventilation direction, a wave bottom extending in the ventilation direction, and a connecting portion connecting the wave crest and the wave bottom, and the connecting portion extends in the width direction of the connecting portion and has a plurality of equal lengths. An evaporator in which louvers are formed side by side in the ventilation direction has been proposed (see Patent Document 1).

  The evaporator described in Patent Document 1 constitutes a refrigeration cycle together with a compressor, a condenser as a refrigerant cooler, an expansion valve as a decompressor, and the like, and is mounted on a vehicle, for example, an automobile, as a car air conditioner. By the way, in such a car air conditioner, condensed water is generated on the surface of the corrugated fins of the evaporator during the operation of the compressor. In general, the surface of the corrugated fin is subjected to a hydrophilic treatment for the purpose of improving the quality. That is, by applying a hydrophilic treatment to the surface of the corrugated fin, the contact angle of the corrugated fin surface is set to 10 degrees or less, and the condensed water generated on the surface of the corrugated fin is spread in a thin film on the entire surface of the corrugated fin. It suppresses the decline in heat exchange performance and scattering of condensed water, and further improves the drainage of condensed water.

  Further, in the above-described car air conditioner, the compressor is turned on / off based on the temperature detected by the thermistor inserted between the connecting portions of the corrugated fins arranged between the adjacent refrigerant flow pipes of the evaporator. Thus, the evaporator is maintained at a low temperature (about 5 ° C.) so that the condensed water does not freeze, cooled through the evaporator, and then passed through the heater core maintained at a high temperature (about 90 ° C.) by the engine cooling water. In general, the temperature of the air blown into the passenger compartment is controlled by mixing the air that has passed through the evaporator and cooled and then bypassed the heater core. However, if the evaporator temperature detected by the thermistor suddenly rises when the compressor is turned off to prevent the condensed water in the evaporator from freezing, the compressor is frequently switched on and off. Fuel consumption deteriorates. Therefore, it is required to improve fuel efficiency by suppressing a rapid rise in the temperature of the evaporator and lengthening the time until the compressor is switched from off to on.

JP 2008-20098 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an evaporator that can respond to the above-mentioned demand and can lengthen the on / off cycle of the compressor.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A plurality of flat refrigerant flow pipes whose longitudinal direction faces the up-down direction and whose width direction faces the ventilation direction are arranged in parallel at intervals in the thickness direction of the refrigerant flow pipe, and adjacent refrigerant flow pipes Ventilation gaps are formed in between, and at least a part of all the ventilation gaps, a wave crest extending in the ventilation direction, a wave bottom extending in the ventilation direction, and a connecting portion connecting the wave crest and the wave bottom. An evaporator in which corrugated fins are arranged, and a plurality of louvers extending in the width direction of the connecting portion are formed in the connecting portion of the corrugated fins side by side in the ventilation direction, and the surface of the corrugated fin is subjected to hydrophilic treatment Because
On the surface of the portion in the range of 50 to 80% of the fin height centering on the corrugated fin connection portion and the central portion of the fin height direction in the louver, the hydrophilicity is lower than other portions and the condensed water is constant. The evaporator provided with the low hydrophilic part hold | maintained as a condensed water layer which has the thickness of.

  2) The evaporator according to 1) above, wherein the contact angle of the low hydrophilic portion is 20 to 30 degrees, and the contact angle of the highly hydrophilic portion excluding the low hydrophilic portion in the corrugated fin is 10 degrees or less.

  According to the evaporators of 1) and 2) above, on the surface of the portion in the range of 50 to 80% of the fin height around the connecting portion of the corrugated fin and the central portion in the fin height direction in the louver, Compared to this, when the evaporator is installed in a car air conditioner, the corrugated fin is not used when the compressor is in operation. A relatively large amount of condensed water generated on the surface is accumulated on the surface of the low hydrophilic portion. Then, if the amount of condensed water stored in the low hydrophilic portion becomes too large and the condensed water layer exceeds a certain thickness, the condensed water cannot be stored in the low hydrophilic portion. The water is drained downward through a gap formed between adjacent louvers in the portion, and flows to the highly hydrophilic portion excluding the low hydrophilic portion in the corrugated fin and drained downward. Therefore, the condensed water generated on the surface of the corrugated fins is drained after collecting a relatively large amount in the low hydrophilic portion, and the cold heat of the condensed water collected in the low hydrophilic portion when the compressor is turned off. Thus, a rapid increase in the temperature of the evaporator can be suppressed. As a result, the time until the compressor is switched from off to on can be extended, and the on / off cycle of the compressor can be lengthened, thereby improving the fuel efficiency of the automobile. In addition, when the compressor is turned off, a rapid increase in the temperature of the evaporator can be suppressed, so that a rapid increase in the discharge temperature, which is the temperature of the air passing through the evaporator, is also suppressed.

  According to the evaporator 2), it is possible to efficiently retain a relatively large amount of condensed water in the low hydrophilic portion while ensuring sufficient drainage from the high hydrophilic portion.

1 is a partially cutaway perspective view showing an overall configuration of an evaporator according to the present invention. It is a figure which expands and shows a part of cross section along the AA line of FIG. It is the figure seen from the ventilation direction upstream which expands and shows a part of evaporator shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the following description, the downstream side in the ventilation direction (the direction indicated by the arrow X in FIG. 1) is the front, and the opposite side is the rear. Further, the left and right when looking forward from the rear, that is, the left and right in FIGS.

  Furthermore, in the following description, the term “aluminum” includes aluminum alloys in addition to pure aluminum.

  FIG. 1 shows the overall configuration of an evaporator according to the present invention, and FIGS. 2 and 3 show the configuration of the main part thereof.

  In FIG. 1, the evaporator (1) includes an aluminum upper header tank (2) and an aluminum lower header tank (3) which are arranged in the vertical direction and spaced apart from each other, and both header tanks (2) ( And 3) a heat exchange core portion (4) provided between them.

  The upper header tank (2) is integrated with the leeward upper header part (5) located on the front side (downstream side of the ventilation direction) and the rear side (upstream side of the ventilation direction) and integrated with the leeward side upper header part (5) And a windward upper header section (6). A refrigerant inlet (7) is provided at the right end of the leeward upper header (5), and a refrigerant outlet (8) is provided at the right end of the leeward upper header (6). The lower header tank (3) includes a leeward lower header portion (9) located on the front side, and an upwind lower header portion (11) located on the rear side and integrated with the leeward lower header portion (9). It has. The inside of the leeward side lower header part (9) and the inside of the leeward side lower header part (11) of the lower header tank (3) are joined across the right end part of both the lower header parts (9) and (11), and the inside Is communicated through the communication member (12) which becomes a passage.

  In the heat exchange core part (4), two flat refrigerant flow pipes (13) whose longitudinal direction faces the up-down direction and whose width direction faces the ventilation direction (front-rear direction) and are spaced apart from each other in the ventilation direction. ) Are arranged in parallel at intervals in the thickness direction (left-right direction) of the refrigerant flow pipe (13), and the pipe sets (14) adjacent to each other in the left-right direction are A ventilation gap (15) is formed between them. The upper end of the leeward refrigerant circulation pipe (13) is connected to the leeward upper header (5), and the lower end is connected to the leeward lower header (9). The upper end portion of the windward side refrigerant circulation pipe (13) is connected to the windward upper header portion (6), and the lower end portion thereof is connected to the windward lower header portion (11).

  Corrugated fins (16) made of an aluminum brazing sheet having a brazing filler metal layer on both sides in the ventilation gap (15) of the heat exchange core part (4) and subjected to hydrophilic treatment on the surface, each pipe assembly (14) It is arranged so as to straddle both the front and rear refrigerant flow pipes (13). Further, corrugated fins (16) made of an aluminum brazing sheet having a brazing material layer on both sides are also arranged outside the pipe assembly (14) of the refrigerant flow pipes (13) at both left and right ends, and corrugated fins ( An aluminum side plate (17) is disposed outside 16) and brazed to the corrugated fins (16). A ventilation gap (15) is also formed between the corrugated fins (16) at the left and right ends and the side plate (17).

  As shown in FIGS. 2 and 3, the corrugated fin (16) includes a wave crest (16a) extending in the front-rear direction, a wave bottom (16b) extending in the front-rear direction, and a wave crest (16a) and a wave bottom (16b) A plurality of louvers (18) extending in the width direction of the connecting portion (16a) are formed in the connecting portion (16a) side by side in the ventilation direction. Corrugated fin (16) connecting portion (16c) and louver (18) in fin height direction (air flow gap (15) formed between refrigerant flow pipes (13) of pipe assemblies (14) adjacent in the left-right direction) The surface of the portion (R) in the range of 50 to 80% of the fin height (H) centering on the center (O) in the width direction is less hydrophilic than the other portions and the condensed water is constant. A low hydrophilic portion (20) is provided which is retained as a condensed water layer having a thickness. The contact angle of the low hydrophilic portion (20) is preferably 20 to 30 degrees. The contact angle of the highly hydrophilic portion (21) excluding the low hydrophilic portion (20) in the corrugated fin (16) is preferably 10 degrees or less. The contact angle of the highly hydrophilic portion (21) is equivalent to the contact angle of a corrugated fin that has been subjected to hydrophilic treatment in a conventional evaporator, for example, an evaporator described in Patent Document 1.

  The above-described evaporator (1) includes a compressor that uses a vehicle engine as a drive source, a condenser that cools the refrigerant discharged from the compressor (refrigerant cooler), and an expansion valve that reduces the refrigerant that has passed through the condenser (decompressor). The refrigeration cycle is configured together with these components and is installed in automobiles as car air conditioners. When the compressor is in operation, the low-pressure gas-liquid mixed phase two-phase refrigerant compressed by the compressor and passed through the condenser and the expansion valve passes through the refrigerant inlet (7) and enters the evaporator (1). It enters into the leeward upper header part (5), flows out from the refrigerant outlet (8) of the leeward upper header part (6) through the entire refrigerant circulation pipe (13). While the refrigerant flows in the refrigerant flow pipe (13), heat exchange is performed with the air passing through the ventilation gap (15), and the refrigerant flows out in a gas phase.

  At this time, it is cooled by the refrigerant flowing in the refrigerant flow pipe (13), and condensed water is generated on the surface of the corrugated fin (16). A relatively large amount of condensed water generated in the low hydrophilic portion (20) on the surface of the corrugated fin (16) is accumulated on the surface of the low hydrophilic portion (20), and a condensed water layer having a constant thickness is formed. If the amount of condensed water stored in the low hydrophilic portion (20) increases and increases too much, and the condensed water layer exceeds a certain thickness, the condensed water may be stored on the surface of the low hydrophilic portion (20). Condensed water is drained downward through a gap formed between adjacent louvers (18) in the connecting portion (16c) of the corrugated fin (16) and is also discharged to the highly hydrophilic portion (21). Flowing.

  Condensed water generated on the surface of the highly hydrophilic portion (21) on the surface of the corrugated fin (16) flows to the refrigerant flow tube (13) side, and the refrigerant flow tube of the wave crest (16a) and the wave bottom (16b). The corners formed on the upper side of the part brazed to (13), and the bent inner part of the part brazed to the refrigerant flow pipe (13) of the wave crest part (16a) and the wave bottom part (16b) Accumulate. When the condensed water overflows from the entering corner and the bent inner side, the condensed water is drained downward through a gap formed between adjacent louvers (18) provided in the connecting portion (16c), and downwind by the wind. And flows downward along the leeward edge of the refrigerant flow pipe (13). Also, the condensed water generated in the low hydrophilic portion (20) and flowing from the low hydrophilic portion (20) to the highly hydrophilic portion (21) is the same as the condensed water generated in the high hydrophilic portion (21). Drained.

  Therefore, the condensed water generated on the surface of the corrugated fin (16) will be drained after collecting a relatively large amount in the low hydrophilic portion (20), and when the compressor is turned off, the low hydrophilic portion (20) The evaporator (1) is cooled by the cold heat of the condensed water accumulated in the evaporator, and the evaporator (1 not shown) detected by the thermistor (not shown) inserted between the connecting portions (16c) of the corrugated fin (16) ) Can be suppressed. As a result, the time until the compressor is switched from off to on can be extended, and the on / off cycle of the compressor can be lengthened, thereby improving the fuel efficiency of the automobile. In addition, since the temperature of the evaporator (1) can be suppressed from rapidly increasing when the compressor is turned off, a rapid increase in the discharge temperature, which is the temperature of the air passing through the evaporator (1), is also suppressed.

  In the above embodiment, the corrugated fins (16) are disposed in all the ventilation gaps (15) of the evaporator (1), but the present invention is not limited to this, and a part of the entire ventilation gap (15). The cool storage material container in which the cool storage material is sealed in the plurality of ventilation gaps (15) may be arranged, and the plurality of corrugated fins (16) may be arranged in the remaining ventilation gaps (15). In this case, cold energy is stored in the regenerator material in the regenerator container during operation of the compressor, and the vehicle uses the cold energy stored in the regenerator material in the regenerator material container when the engine stops and the compressor stops. The room can be cooled.

  The evaporator according to the present invention is suitably used in a refrigeration cycle constituting a car air conditioner of a vehicle.

(1): Evaporator
(12): Refrigerant distribution pipe
(15): Ventilation gap
(16): Corrugated fin
(16a): Wave peak
(16b): Wave bottom
(16c): Connection part
(18): Louva
(20): Low hydrophilic part
(21): Highly hydrophilic part

Claims (2)

A plurality of flat refrigerant flow pipes whose longitudinal direction faces the up-down direction and whose width direction faces the ventilation direction are arranged in parallel at intervals in the thickness direction of the refrigerant flow pipe, and between adjacent refrigerant flow pipes Ventilation gaps are formed, and at least some of the ventilation gaps include a wave crest extending in the ventilation direction, a wave bottom extending in the ventilation direction, and a connecting portion connecting the wave crest and the wave bottom. This is an evaporator in which corrugated fins are arranged, and a plurality of louvers extending in the width direction of the connecting portions are formed in the connecting portions of the corrugated fins side by side in the ventilation direction, and the surface of the corrugated fins is subjected to hydrophilic treatment. And
On the surface of the portion in the range of 50 to 80% of the fin height centering on the corrugated fin connection portion and the central portion of the fin height direction in the louver, the hydrophilicity is lower than other portions and the condensed water is constant. The evaporator provided with the low hydrophilic part hold | maintained as a condensed water layer which has the thickness of. The evaporator according to claim 1, wherein the contact angle of the low hydrophilic portion is 20 to 30 degrees, and the contact angle of the highly hydrophilic portion excluding the low hydrophilic portion in the corrugated fin is 10 degrees or less.

Images