JP2015007518A - Cold storage heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold storage heat exchanger capable of suppressing reduction in the total heat storage amount of overall cold storage medium vessels due to a refrigerant overheated region, appropriately maintaining air cooling function by a heat storage medium when a compressor stops operating, and ensuring cooling performance.SOLUTION: In a cold storage heat exchanger in which refrigerant tubes 3 are provided in two front and back rows, a counter-flow technique is adopted such that a downstream side (an upstream side) of refrigerant flow corresponds to an upstream side (a downstream side) of air flow, the refrigerant tubes 3 are partitioned into four groups by four paths having inverted flow directions, an arrangement ratio of cold storage medium vessels 5 (ratio of the arrangement number of cold storage medium vessels 5 to the arrangement number of refrigerant tubes 3) in the fourth path P4 (and first path P1) including an overheat region in which refrigerant is heated to generate sensible heat to increase temperature is set lower than an arrangement ratio of cold storage medium vessels 5 in the other paths (second path P2 and third path P3).

Description

  The present invention relates to a cold storage heat exchanger that can be used as an evaporator (evaporator) in a refrigeration cycle such as a car air conditioner and can store and cool by a cold storage material.

  Generally, a cold storage heat exchanger is arranged in a space between a plurality of flat refrigerant tubes arranged in parallel at a predetermined interval with the flat portions facing each other, and the flat portions of adjacent refrigerant tubes, and flows through the space. It is comprised including the fin which contacts air, and the cool storage material container which is integrated in the row | line | column of these refrigerant pipes and fins, and the cool storage material is accommodated.

  The cold storage heat exchanger is usually used as an evaporator in a refrigeration cycle such as a car air conditioner. Therefore, the refrigerant supplied via the condenser and the expansion valve by the compressor driven by the engine flows through the refrigerant pipe and evaporates here. And the heat for evaporation is taken from the air which flows through the space | gap between the flat parts of an adjacent refrigerant pipe, and cooling air is cooled. At the same time, the cold storage material in the cold storage material container is stored cold. After that, when the engine stops at an idle stop or the like and the compressor stops, the air is cooled using the cold energy stored in the cold storage material to ensure the cooling capacity.

  In the cold storage heat exchanger (cold storage evaporator) described in Patent Document 1, two fins and one cold storage material container are disposed between three refrigerant tubes arranged in parallel, and the cold storage material container is a refrigerant. It is uniformly arranged at a constant rate in the entire area where the tubes are arranged. Further, in the cold storage heat exchanger (cold storage evaporator) described in Patent Document 2, the refrigerant pipe and the cold storage material container are integrally formed, and the cold storage material container is uniformly in a ratio of 1: 1 to the refrigerant pipe. It is arranged.

JP 2011-12947 A JP 2011-149684 A

By the way, in the evaporator, the refrigerant flowing in the gas-liquid mixed state from the expansion valve exchanges heat with the blown air and absorbs heat, and while the phase change is caused by latent heat, the refrigerant temperature is maintained at a constant low temperature. When completed, the vaporized refrigerant changes its sensible heat and rises in temperature, generating an overheating region.
The regenerator container disposed in the refrigerant pipe disposition region that becomes the overheated area is heat-exchanged with a relatively high-temperature refrigerant, so that the regenerator efficiency is low, and the total regenerator amount of the entire regenerator container decreases, The air cooling function by the cold storage material when the compressor was stopped was impaired.

  In view of such conventional problems, the present invention suppresses a decrease in the total cold storage amount of the entire cold storage container due to the refrigerant overheating region in the cold storage heat exchanger, and the air cooling function by the cold storage material when the compressor is stopped It is an object to maintain cooling well and ensure cooling performance.

  The regenerative heat exchanger according to the present invention is arranged in a space between a plurality of flat refrigerant tubes arranged in parallel at a predetermined interval with the flat portions facing each other, and the flat portions of adjacent refrigerant tubes. A fin that comes into contact with flowing air, and a cold storage material container that is arranged in place of the fin in a gap between flat portions of some adjacent refrigerant pipes and that stores the cold storage material.

  And the arrangement | positioning ratio of the said cool storage material container in the refrigerant | coolant pipe | tube arrangement | positioning area | region containing the overheating area where the refrigerant | coolant in the said refrigerant | coolant pipe | steam sensible heat | fever rises is made smaller than the arrangement | positioning ratio in another refrigerant | coolant pipe | tube arrangement | positioning area.

  According to the present invention, since the cold storage efficiency of the cold storage container disposed in the refrigerant pipe arrangement region including the overheated area is small, the cold storage material can be reduced by making it smaller than the arrangement ratio in the other refrigerant pipe arrangement regions. The total cold storage amount of the entire container can be increased, and the air cooling function by the cold storage material when the compressor is stopped, such as idling stop, can be well maintained to ensure the cooling performance.

The front view of the cool storage heat exchanger which shows 1st Embodiment of this invention Top view of the regenerative heat exchanger Bottom view of the regenerative heat exchanger XX arrow sectional view of FIG. YY arrow cross-sectional view of FIG. Schematic perspective view showing the flow of refrigerant in the above regenerative heat exchanger Front view of cold storage heat exchanger showing the second embodiment Schematic perspective view showing the flow of refrigerant in the above regenerative heat exchanger Front view of cold storage heat exchanger showing the third embodiment

Hereinafter, embodiments of the present invention will be described in detail.
1 to 6 are a front view, a plan view, a bottom view, a cross-sectional view taken along the line XX in FIG. 1, and a Y in FIG. 1, respectively, showing a cold storage heat exchanger (cold storage evaporator) showing a first embodiment of the present invention. -Y arrow sectional drawing, It is a schematic perspective view which shows the flow of the refrigerant | coolant in a cool storage heat exchanger. The upstream side in the air flow direction with respect to the heat exchanger is referred to as the front side, and the downstream side is referred to as the rear side.

  The cold storage heat exchanger according to the present embodiment includes a plurality of flat refrigerant tubes 3 communicating with the upper header tank 1 and the lower header tank 2 and fins 4 disposed in the gaps between the adjacent refrigerant tubes 3 and 3. And the cool storage material container 5 arrange | positioned instead of the fin 4 in a part of space | gap, and the side plates 6 of both sides are comprised.

  The upper header tank 1 extends in the horizontal direction, and is divided into two tanks 1A and 1B in the front-rear direction orthogonal to the extending direction. Here, a refrigerant inlet 7 is formed at one end of the rear tank 1A, and a refrigerant outlet 8 is formed at one end of the front tank 1B adjacent thereto.

  The lower header tank 2 extends in the horizontal direction below the upper header tank 1 in the same manner as the upper header tank 1, and is divided into two tanks 2A and 2B in the front-rear direction orthogonal to the extending direction. .

  The refrigerant pipe 3 has a flat shape, and is arranged in parallel at a predetermined interval with the flat portions facing each other. Here, the refrigerant pipes 3 are arranged in two front and rear rows, the rear first row communicates the upper tank 1A and the lower tank 2A, and the front second row is the upper tank 1B and the lower tank. Communicate with 2B. In addition, a gap is formed between the flat portions of the refrigerant pipes 3 and 3 adjacent to each other in the juxtaposed direction so as to allow air to exchange heat with the refrigerant in the refrigerant pipes 3 and 3.

  The fins 4 are corrugated fins, and are arranged for improving heat exchange efficiency between the gaps, that is, between the flat portions of the adjacent refrigerant pipes 3 and 3.

  The regenerator material container 5 is a flat container in which a regenerator material is enclosed, and a cold storage material inlet 5a (closed after the regenerator material is enclosed) is formed in the lower end portion, and the flatness of some adjacent refrigerant tubes 3 and 3 is formed. It replaces with the fin 4 and is arrange | positioned at the space | gap between parts. The fins 4 and the regenerator container 5 are formed across the two front and rear refrigerant tubes 3. The ratio of the number of the regenerator containers 5 to the number of refrigerant tubes 3 will be described later.

  In the present embodiment, the refrigerant pipe 3 is divided into a front row and a rear row, the front row is further divided into two groups, and the rear row is further divided into two groups. Therefore, in the entire heat exchanger, as shown in the schematic diagram of FIG. 6 (and the one-dot chain line in FIG. 1), the first and second passes (P1, P2) on the rear side along the refrigerant flow direction and the front side And the third and fourth paths (P3, P4).

  In order to realize such first to fourth paths (P1 to P4), the upper header tank 1 (1A, 1B) and the lower header tank 2 (2A, 2B) are partitioned as follows.

Referring to FIG. 2, tanks 1 </ b> A and 1 </ b> B are separated from each other by a partition 11 on the right side in the longitudinal direction, but communicate with each other at a communication part 12 on the left side. Each tank 1A, 1B is provided with a partition 13 at the center in the longitudinal direction.
On the other hand, as shown in FIG. 3, the tanks 2 </ b> A and 2 </ b> B are separated from each other by a partition 14 and are not in communication.

  In such a 4-pass system, the refrigerant is supplied by an engine-driven compressor via a condenser and an expansion valve, flows into the upper tank 1A on the rear side from the refrigerant inlet 7, and extends in front of the partition plate 13 in front. From the right half of the direction shown, the refrigerant flows through the refrigerant pipe 3 group in the first path P1 downward and reaches the lower tank 2A. Then, the refrigerant pipe 3 of the second path P2 flows upward from the left half of the lower tank 2A, reaches the upper tank 1A, and reaches the front upper tank 1B via the communication portion 12 from the upper tank 1A.

  Then, the refrigerant flows through the refrigerant pipe 3 group in the third path P3 downward from the left side portion of the front upper tank 1B and reaches the front lower tank 2B. Then, it flows upward from the right side portion of the lower tank 2B through the refrigerant pipe 3 group in the fourth path P4, reaches the front upper tank 1B, and flows out from the refrigerant outlet 8.

  Here, when the refrigerant flows through the refrigerant pipe 3, the air passing through the gap is cooled via the fins 4. At this time, cold storage is performed in the cold storage material in the cold storage material container 5 disposed between the flat portions of some of the adjacent refrigerant tubes 3 and 3. Thereafter, when the engine is stopped due to an idle stop or the like and the compressor is stopped, the air is cooled by using the cold energy stored in the cool storage material in the cool storage material container 5 to ensure the cooling capacity.

  In the regenerative heat exchanger having such a configuration, the refrigerant flowing in the gas-liquid mixed state from the refrigerant inlet 7 exchanges heat with the blown air and absorbs heat, but the vaporization is not completed from the first pass P1 to the third pass P3. The phase changes in the latent heat state, and the refrigerant temperature is maintained at a constant low temperature. Then, the phase change (vaporization) ends in the middle of the fourth pass P4, and on the downstream side, the vaporized refrigerant changes in sensible heat and rises in temperature to become a superheated region.

  And the cool storage material container arrange | positioned in the 4th path | pass P4 area | region containing the overheating area of the refrigerant | coolant pipe | tube 3 group is compared with the temperature of the refrigerant | coolant in which the temperature of the refrigerant | coolant in this overheating area is maintained in another latent heat state. Since it is high, the cold storage efficiency (cold storage amount) by the refrigerant decreases. In the counter system in which the refrigerant flow is downstream (rear side) on the upstream side (front side) of the blown air as in the present embodiment, each of the regenerator containers 5 is connected to the front path and the rear side as described above. It is disposed across the side path.

  Therefore, in the first embodiment, paying attention to the above points, the arrangement ratio of the cold storage material containers 5 in the fourth path P4 (and the first path P1) including the overheating region (cold storage with respect to the number of refrigerant tubes 3 arranged). The ratio of the number of material containers 5 disposed) is set to be smaller than the ratio of the cold storage material containers 5 disposed in the other paths (second path P2 and third path P3).

  Specifically, the cool storage material containers 5 in the second pass P2 and the third pass P3 are arranged at six equal intervals in the longitudinal direction of the cool storage heat exchanger (the number of the refrigerant pipes 3 is the same as the second pass P2 and the third pass). P3 and 12 are arranged in total (24 in total), whereas the number of the regenerator containers 5 in the fourth pass P4 and the first pass P1 is four (the number of refrigerant pipes 3 is 4). 12 on the pass side and 1 on the pass side, for a total of 24).

  As described above, the arrangement ratio (= 4/24 = 1/6) of the cool storage material container 5 with low cool storage efficiency in the path including the overheated region is set to the cool storage with relatively high cool storage efficiency in the other paths. The ratio of the material container 5 to the refrigerant pipe 3 is set smaller than (6/24 = 1/4).

  On the other hand, when the arrangement ratio of all the ten cool storage material containers 5 with respect to the refrigerant pipe 3 is made constant, the cool storage material in the fourth pass P4 and the first pass P1, and the second pass P2 and the third pass P3. Five containers 5 are arranged at a time.

  Therefore, compared with the case where this embodiment arrange | positions the whole cool storage material container 5 by the equal ratio as mentioned above, the arrangement | positioning ratio of the cool storage material container 5 in a path | pass with high cool storage efficiency is large, and cool storage efficiency is low. Since the arrangement ratio of the cool storage material containers 5 in the path is reduced, the total cool storage amount of the entire ten cool storage material containers 5 is increased. Thereby, even when the compressor is stopped due to idle stop or the like, the cooling amount by heat exchange of the blown air with the cold storage material container 5 is increased, and the temperature of the air sent to the room is greatly reduced, and the good cooling performance Can be secured.

  Here, if the total number of the cool storage material containers 5 is increased, the total cool storage amount increases. However, the amount of cold heat of the refrigerant required for storing the cool storage material container 5 after the start of operation of the heat exchanger increases, so that the coolant and the blown air The amount of heat exchange decreases, and good cooling performance cannot be ensured.

Accordingly, in consideration of these factors, the appropriate number of the regenerator containers 5 is determined (10 in this embodiment), and the total number of the regenerator containers 5 is reduced by reducing the arrangement ratio of the superheat zone. The amount of cold storage can be increased.
7 and 8 show a second embodiment.

  In the present embodiment, the refrigerant pipe 3 is divided into a front row and a rear row, the front row is further divided into three groups, and the rear row is further divided into three groups. Therefore, as shown in the schematic diagram of FIG. 8, the entire heat exchanger is divided into a first path P1 to a third path P3 on the rear side and a fourth path P6 to a sixth path P6 on the front side.

In order to realize such first path P1 to sixth path P6, the upper header tank 1 (1A, 1B) and the lower header tank 2 (2A, 2B) are partitioned as follows.
Referring to FIG. 8, tanks 1 </ b> A and 1 </ b> B are separated from each other by a partition 21 and are not in communication. Each tank 1A, 1B is provided with a partition 22 near one end in the longitudinal direction.

  The tanks 2A and 2B are separated from each other by a partition 23, but communicate with each other through a communication portion 24 on the other end side. Each tank 2A, 2B is provided with a partition 25 near the other end in the longitudinal direction.

  In such a 6-pass system, the refrigerant flows into the upper tank 1A on the rear side from the refrigerant inlet 7, flows downward through the refrigerant pipe 3 group of the first path P1, and reaches the lower tank 2A. And it flows upward through the refrigerant | coolant pipe | tube 3 group of the 2nd path | pass P2 from the longitudinal direction intermediate part of the lower tank 2A, and reaches the upper tank 1A. Then, it flows downward from the other end side in the longitudinal direction of the upper tank 1A through the refrigerant pipe 3 group in the third path P3 and reaches the lower tank 2A. Then, the lower tank 2A reaches the lower tank 2B on the front side through the communication portion 24.

  Then, it flows upward from the other end in the longitudinal direction of the lower tank 2B on the front side through the refrigerant pipe 3 group in the fourth path P4 and reaches the upper tank 1B. And it flows downward through the refrigerant pipe 3 group of the 5th path P5 from the longitudinal direction middle part of upper tank 1B, and reaches lower tank 2B. Then, the sixth tank P6 flows upward from one longitudinal end of the lower tank 2B and reaches the upper tank 1B. Then, it flows out from the refrigerant outlet 8.

  The number of passes is set according to the cooling performance requirement, but the increase or decrease in the number of passes is determined in consideration of changes in the refrigerant flow rate and pressure loss.

  Also in the second embodiment, the refrigerant that flows in the gas-liquid mixed state from the refrigerant inlet 7 exchanges heat with the blown air and absorbs heat. From the first pass P1 to the fifth pass P5, vaporization is not completed and latent heat is generated. The phase changes, the refrigerant temperature is maintained at a constant low temperature, the phase change (vaporization) ends in the middle of the sixth pass P6, and an overheating region is generated downstream thereof.

  Therefore, the arrangement ratio of the cool storage material containers 5 in the sixth pass P6 (and the first pass P1) including the superheat zone (the ratio of the number of the cool storage material containers 5 to the number of the refrigerant pipes 3) is set to other values. It sets smaller than the arrangement | positioning ratio of the cool storage material container 5 in a path | pass (2nd path | pass P2-5th path | pass P5).

  Specifically, the number of the cold storage material containers 5 in the fifth pass P5 and the second pass P2, and the fourth pass P4 and the third pass P3 is set to be equal to four in the longitudinal direction (the arrangement of the refrigerant pipes 3). The number of the regenerator heat exchangers in the sixth pass P6 and the first pass P1 is two at the same interval in the longitudinal direction (refrigerant), whereas the number is arranged in a total of 16 in each of the eight passes in the front and rear passes. The number of tubes 3 is 16).

  Also in the present embodiment, as in the first embodiment, the arrangement ratio of the cold storage material containers 5 in the path including the superheated region with low cold storage efficiency is small, and the arrangement ratio of the cold storage material containers 5 in the other paths with high cold storage efficiency. Since the total cold storage amount is increased, the cooling effect at idle stop or the like can be enhanced.

  In 1st and 2nd embodiment, since the cool storage material container 5 was arrange | positioned at equal intervals in the most downstream path | pass including a superheat zone, the dispersion | variation in the air volume distribution of the air which passes a cool storage heat exchanger can be suppressed.

FIG. 9 shows a third embodiment.
In the present embodiment, in the 6-pass type regenerative heat exchanger similar to the second embodiment, the arrangement ratio of the regenerator containers 5 in the 6-pass including the superheat region is the same and two are provided, but the overheat region is generated. The two cool storage material containers 5 are arranged in a portion excluding the region.

  That is, when the refrigerant in the gas-liquid mixed state flows out from the fifth path P5 to the lower tank 2B and then flows toward the sixth path P6 side, as shown in the dashed line in the lower tank 2B, Due to inertia, the liquid refrigerant is biased to flow toward the end side (right side in the figure).

  As a result, in the sixth pass P6, the refrigerant pipe 3 on the side closer to the fifth pass P5 (the left side in the drawing) flows in the refrigerant having a small liquid component and a large gas component, and the completion of vaporization is accelerated and the refrigerant pipe 3 is overheated. Therefore, as shown in the figure, the superheat region SH is formed in a trapezoidal shape.

  Therefore, the refrigerant tube 3 group region including the superheat region SH is not provided with the cold storage material container 5 adjacent thereto, and the refrigerant tube 3 group region including the four refrigerant tubes 3 group regions including the front and rear four regions not including the superheat region is 2 in total. The cool storage material containers 5 are arranged at equal intervals.

  Thus, the cold storage efficiency can be ensured also in these cool storage material containers 5 by arranging the two cool storage material containers 5 collectively in the refrigerant tube 3 group region not including the superheat region SH. The total cool storage amount can be increased as much as possible to further improve the cooling performance when the compressor is stopped, such as an idle stop.

  In the above embodiment, the refrigerant tube group is provided in two rows in the front and rear, and is applied to a counter-type regenerative heat exchanger in which the refrigerant flow is on the downstream side (upstream side) and the refrigerant flow is on the downstream side (upstream side). However, the present invention can also be applied to a cold storage heat exchanger in which a group of refrigerant tubes is provided, and by reducing the arrangement ratio of the cold storage material container in the refrigerant tube arrangement region including the superheated region such as the final pass. A similar effect can be obtained.

  In addition, when the number of passes is increased or the like, and the upstream side of the final pass also includes a superheated area, the arrangement ratio of the regenerator container in the upstream path including the superheated area may be reduced. Of course.

  The illustrated embodiments are merely examples of the present invention, and the present invention is not limited to those directly described by the described embodiments, and various improvements and modifications made by those skilled in the art within the scope of the claims. Needless to say, it encompasses changes.

1 (1A, 1B) Upper header tank 2 (2A, 2B) Lower header tank 3 Refrigerant pipe 4 Fin 5 Cold storage material container 7 Refrigerant inlet 8 Refrigerant outlet 11, 13, 14, 21, 22, 23, 25 Partition 12, 24 communication part P1 1st pass P2 2nd pass P3 3rd pass P4 4th pass P5 5th pass P6 6th pass SH Superheated area

Claims (7)

A plurality of flat refrigerant tubes arranged in parallel at a predetermined interval with the flat portions facing each other, fins arranged in a space between the flat portions of adjacent refrigerant tubes and contacting with air flowing through the space; A cold storage heat exchanger comprising a cold storage material container in which a cold storage material is accommodated in place of the fins in a space between flat portions of refrigerant pipes adjacent to each other,
The arrangement ratio of the cold storage material container in the refrigerant pipe arrangement area including the superheated area where the temperature of the refrigerant in the refrigerant pipe is increased by sensible heat is made smaller than the arrangement ratio in the other refrigerant pipe arrangement areas. Regenerative heat exchanger.   The plurality of refrigerant tubes are connected at both end portions thereof to communicate with the header tank, and a plurality of refrigerant flow directions are inverted between adjacent refrigerant tube groups by a partition wall formed in the at least some of the header tanks. 2. The refrigerant pipe group that is divided into the refrigerant pipe groups of the first and second refrigerant pipe groups, and the arrangement ratio of the cold storage material containers in the refrigerant pipe group including the superheated area is smaller than the arrangement ratio of the other refrigerant pipe groups. Cold storage heat exchanger.   The regenerative heat exchanger according to claim 2, wherein the refrigerant tube group including the overheated region includes at least a refrigerant tube group located downstream in the refrigerant flow direction.   The plurality of refrigerant pipes are formed with a pair of refrigerant pipe groups whose both ends are connected to and connected to the header tank. The refrigerant pipe group on the upstream side in the refrigerant flow direction is the downstream side in the air blowing direction and the downstream side in the refrigerant flow direction. Are arranged side by side on the upstream side in the air blowing direction, and a counter flow type heat exchanger in which adjacent headers of the pair of refrigerant pipe groups on the upstream side and the downstream side in the refrigerant flow direction are connected in communication. The regenerative heat exchanger according to claim 2 or 3, wherein the regenerative heat exchanger is provided.   The cold storage heat exchanger according to claim 4, wherein the cold storage material container is disposed across the refrigerant pipe groups on the upstream side and the downstream side in the refrigerant flow direction.   The cold storage material container according to any one of claims 2 to 5, wherein the cold storage material container is arranged at an equal ratio with respect to all the refrigerant tubes in the refrigerant tube group including the superheat zone. Heat exchanger.   The said cool storage material container is concentrated and arrange | positioned in the refrigerant | coolant pipe | tube arrangement | positioning area | region except the refrigerant | coolant pipe arrangement | positioning area | region used as an overheated area in the refrigerant | coolant tube group containing the said superheated area. The regenerative heat exchanger according to any one of 5.