JP5509830B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger such as an evaporator constituting a refrigeration cycle used for cooling a product in a vending machine or the like.

  Conventionally, in a vending machine that sells products such as canned beverages and plastic bottled beverages, an evaporator that is a component device of a refrigeration cycle inside (inside) the product cabinet of the main body cabinet that is the main body of the vending machine Etc. are provided.

  As shown in FIG. 8, such an evaporator 34 is formed in such a manner that flat refrigerant passage tubes 341 each having a plurality of refrigerant flow paths arranged in a meandering manner, and the inlet side of these refrigerant passage tubes 341 has an inlet. The side header 342 is connected to the outlet side header 343 on the outlet side of the refrigerant passage pipe 341. A plurality of fin members 344 are erected in such a manner as to be thermally connected to the refrigerant passage pipes 341.

  The fin member 344 is for accelerating heat exchange between the refrigerant passing through the refrigerant passage pipe 341 and the internal air of the product storage box passing through the periphery thereof. As shown in the drawing, one having a plurality of raised portions 3441 formed on the surface is known (see, for example, Patent Document 1).

JP 2004-270959 A

  By the way, in the evaporator (heat exchanger) applied in a vending machine, the surface of the fin member 344 etc. becomes below freezing point, and the phenomenon called frost which frost adheres arises. Therefore, the defrosting operation is performed to remove the attached frost as necessary. However, if the separation distance between the adjacent raised portions 3441 is not sufficiently secured, the shortest distance is not sufficiently secured. In other words, a so-called bridge phenomenon occurs in which water droplets straddle between adjacent cut and raised portions 3441. If such water droplet bridging occurs, heat exchange at the edge of the cut-and-raised portion 3441 is not performed well, and as a result, there is a problem that heat transfer performance cannot be improved.

  In view of the above circumstances, an object of the present invention is to provide a heat exchanger capable of suppressing the occurrence of water droplet bridging between adjacent raised portions and improving heat transfer performance. .

To achieve the above object, the heat exchanger according to the present onset Ming, a refrigerant tube constituting the flow path of the refrigerant, a thermal connectable with further aspect is arranged in the refrigerant tube, the refrigerant In the heat exchanger comprising a refrigerant that passes through the passage tube and a fin member that promotes heat exchange between the fluid that passes around the passage tube, the fin member has a plurality of raised portions formed on a surface thereof, and between adjacent cut-and-raised portions with each other is shall be formed notch, with the θ angle of attack-raised portion is 20 ° ~ 29 °, the surface of the fin member between the cut-and-raised portions adjacent to each other The distance δL along the direction satisfies the following relational expression, where a is the maximum height at the cut and raised portion and t is the thickness of the fin member.
(Formula) δL> (2a + t) · tan θ (however, 20 ° ≦ θ ≦ 29 °)

  According to the present invention, the fin member has a plurality of cut-out portions formed on the surface, and a cut-out portion is formed between the cut-out portions adjacent to each other. The separation distance is secured. As a result, it is possible to suppress the occurrence of water droplet bridges between the adjacent raised portions, thereby improving the transmission performance.

FIG. 1 is a cross-sectional view showing a case where an internal structure of a vending machine to which a heat exchanger according to an embodiment of the present invention is applied as an evaporator is viewed from the front. 2 is a cross-sectional side view showing the internal structure of the vending machine shown in FIG. FIG. 3 is a perspective view showing the evaporator (heat exchanger according to an embodiment of the present invention) shown in FIG. FIG. 4 is a schematic diagram schematically showing a main part of the evaporator (heat exchanger according to the embodiment of the present invention) shown in FIG. FIG. 5 is an enlarged perspective view showing an enlarged main part of the fin member shown in FIGS. 3 and 4. FIG. 6 is an explanatory view schematically showing a longitudinal section of the fin member shown in FIG. FIG. 7 is an explanatory view schematically showing a longitudinal section of the fin member shown in FIG. FIG. 8 is a perspective view showing a conventional evaporator. FIG. 9 is an enlarged perspective view showing a main part of the fin member shown in FIG. 8 in an enlarged manner.

  Hereinafter, preferred embodiments of a heat exchanger according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing a case where an internal structure of a vending machine to which a heat exchanger according to an embodiment of the present invention is applied as an evaporator is viewed from the front. The vending machine illustrated here includes a main body cabinet 1.

  The main body cabinet 1 has a rectangular shape with an open front surface. The main body cabinet 1 is provided with three independent commodity containers 3 partitioned by, for example, two heat insulating partition plates 2 in a side-by-side manner. This product storage 3 is for storing products such as canned beverages and beverages containing plastic bottles while maintaining them at a desired temperature, and has a heat insulating structure.

  2 is a cross-sectional side view showing the internal structure of the vending machine shown in FIG. As shown in FIG. 2, an outer door 4 and an inner door 5 are provided on the front surface of the main body cabinet 1. The outer door 4 is for opening and closing the front opening of the main body cabinet 1, and the inner door 5 is for opening and closing the front surface of the commodity storage 3. The inner door 5 is divided into upper and lower parts, and the upper door 5a opens and closes when a product is replenished.

  The product storage 3 is provided with a product storage rack 6, a carry-out mechanism 7 and a carry-out shooter 8. The commodity storage rack 6 is for storing commodities in a manner arranged in the vertical direction. The carry-out mechanism 7 is provided at the lower part of the product storage rack 6 and is used to carry out the products at the bottom of the product group stored in the product storage rack 6 one by one. The carry-out shooter 8 is for guiding the product carried out from the carry-out mechanism 7 to the product take-out port 4 a provided in the outer door 4.

  An evaporator 24 and a heater H are disposed below the carry-out shooter 8. The evaporator 24 is disposed on the front side of the rear duct D, and is sequentially connected through a compressor 21, a condenser 22, an expansion mechanism 23 and a refrigerant pipe 25 disposed in the machine room 9 to form a refrigeration cycle 20. doing. The compressor 21 sucks the refrigerant through the suction port, compresses the sucked refrigerant to be in a high-temperature and high-pressure state (high-temperature and high-pressure refrigerant), and discharges it from the discharge port. The condenser 22 condenses the refrigerant that passes therethrough. More specifically, the refrigerant compressed by the compressor 21 and discharged from the discharge port and sent out through the refrigerant pipe 25 is condensed by exchanging heat with ambient air. The expansion mechanism 23 is for adiabatic expansion by reducing the pressure of the refrigerant passing therethrough.

  By circulating the refrigerant in the refrigeration cycle 20, the refrigerant compressed by the compressor 21 is condensed by the condenser 22, and then adiabatically expanded by the expansion mechanism 23 and passes through the evaporator 24. When the refrigerant passes through the evaporator 24, heat exchange is performed with the internal air of the commodity storage 3 in which the evaporator 24 is disposed, and the refrigerant evaporates to cool the internal air. The evaporated refrigerant is sucked into the compressor 21.

  The cooled internal air moves inside the product storage 3 by driving the internal blower fan F1, so that the product stored in the product storage rack 6 of the product storage 3 has a desired temperature (for example, 5 ° C.). It will be cooled down.

  The heater H is arrange | positioned in the front area of the internal ventilation fan F1. The heater H heats the surrounding air when energized. The air heated by the heater H moves inside the product storage case 3 by driving the internal blower fan F1, so that the product stored in the product storage rack 6 of the product storage case 3 has a desired temperature (for example, 55 ° C.).

  3 and FIG. 4 show the evaporator 24 (heat exchanger according to the embodiment of the present invention) shown in FIG. 2, respectively, FIG. 3 is a perspective view, and FIG. It is a schematic diagram which shows the principal part typically. The evaporator 24 exemplified here includes a refrigerant passage tube 241, an inlet side header 242, an outlet side header 243, and a fin member 244. The refrigerant passage pipe 241 is a flat pipe in which a plurality of refrigerant flow paths 241a are arranged side by side, and is formed to meander from side to side. In the example shown in FIGS. 3 and 4, the two refrigerant passage tubes 241 are formed to meander from side to side in such a manner that they are arranged at the same height level.

  The inlet-side header 242 is connected to the upper end of the refrigerant passage pipe 241 and is provided in such a manner as to communicate with each flow path 241 a of the refrigerant passage pipe 241. The inlet-side header 242 is for adiabatically expanding by the expansion mechanism 23 and for supplying the refrigerant supplied through the refrigerant pipe 25 to each flow path 241a.

  The outlet-side header 243 is connected to the lower end of the refrigerant passage tube 241 and is provided in a form communicating with each flow path 241 a of the refrigerant passage tube 241. The outlet header 243 is for sending the refrigerant that has passed through each flow path 241 a, that is, the refrigerant that has evaporated through heat exchange, to the refrigerant pipe 25 connected to the compressor 21.

  The fin member 244 is erected in such a manner that it is thermally connected to a portion of the refrigerant passage tube 241 that extends in the horizontal direction. This fin member 244 is for accelerating heat exchange between the refrigerant passing through the refrigerant passage tube 241 and the internal air of the product storage case 3 passing through the periphery of the fin member 244.

  FIG. 5 is an enlarged perspective view showing an enlarged main part of the fin member 244 shown in FIGS. 3 and 4. As shown in FIG. 5, on the surface of the fin member 244, a plurality of raised portions (louvers) 2441 are formed side by side along the direction in which the internal air of the product storage case 3 passes. These cut-and-raised portions 2441 are respectively perpendicular to the direction in which the internal air of the commodity storage 3 passes and have a ridge 2442 having a ridge line extending along the surface direction of the fin member 244, and the commodity storage 3 Is formed in such a manner that a valley portion 2443 that is orthogonal to the direction in which the internal air passes and extends along the surface direction of the fin member 244 is integrated.

  In addition, a notch 2444 is formed between the adjacent raised portions 2441, whereby a separation distance (δL) between the adjacent raised portions 2441, that is, between the adjacent raised portions 2441. A distance along the surface direction of the fin member 244 is secured.

  FIG. 6 is an explanatory view schematically showing a longitudinal section of the fin member 244 shown in FIG. As shown in FIG. 6, a notch 2444 is formed so that a separation distance δL between adjacent raised portions 2441 satisfies the following relational expression.

(Formula) δL> (2a + t) · tan θ
Here, δL is a separation distance between adjacent raised portions 2441, a is the maximum height of the raised portions 2441 from the surface of the fin member 244, t is the thickness of the fin member 244, and θ is the angle of attack. Yes.

  Thus, by making the separation distance δL between the adjacent raised portions 2441 larger than δLc, that is, (2a + t) · tan θ, the shortest distance Lm between the adjacent raised portions 2441 does not exist. In this case, the shortest distance between adjacent raised portions, that is, (2a + t) · cos θ can be made larger. Since the shortest distance Lm can be made larger than (2a + t) · cos θ, as shown in FIG. 7, it becomes larger than the height of the water droplet S generated by performing the defrosting operation of the evaporator 24, and as a result. In addition, there is no possibility that a so-called bridge in which the water droplets S straddle between the adjacent raised portions 2441 is generated.

  Moreover, in the heat exchanger (evaporator 24) in this Embodiment, the magnitude | size of the attack angle (theta) of the cut-and-raised part 2441 is a magnitude | size of 20 degrees-29 degrees from a viewpoint of ensuring a sufficient average heat transfer rate. It is preferable that it has a size of 22 ° to 27 °.

  As described above, according to the heat exchanger according to the embodiment of the present invention, the fin member 244 has a plurality of cut and raised portions 2441 formed on the surface, and between the cut and raised portions 2441 adjacent to each other. Since the cutout portion 2444 is formed, a separation distance δL between the adjacent cut and raised portions 2441 is ensured. Thereby, it is possible to suppress the occurrence of a bridge of water droplets S between adjacent raised portions 2441, thereby improving the transmission performance.

  In particular, when the distance δL between the adjacent raised portions 2441 satisfies the above relational expression, the shortest distance Lm between the adjacent raised portions 2441 can be made larger than (2a + t) · cos θ. Therefore, it becomes larger than the height of the water droplet S produced by performing the defrosting operation of the evaporator 24 and adhered to the cut and raised portion 2441, and as a result, the water droplet S straddles between the cut and raised portions 2441 adjacent to each other. There is no risk of bridging. Therefore, it is possible to reliably prevent the water droplet S from being bridged between the adjacent raised portions 2441 and to improve the heat transfer performance.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made. In the embodiment described above, the heat exchanger applied as the evaporator 24 of the vending machine has been described. However, the present invention is not limited to the evaporator 24 of the vending machine, and may be applied to the condenser 22. The present invention may be applied to other cooling devices.

  As described above, the heat exchanger according to the present invention is useful for an evaporator constituting a refrigeration cycle used for cooling a product in a vending machine or the like.

DESCRIPTION OF SYMBOLS 1 Main body cabinet 3 Commodity storage box 24 Evaporator 241 Refrigerant passage pipe 242 Inlet side header 243 Outlet side header 244 Fin member 241a Flow path 2441 Cut-up part 2442 Mountain part 2443 Valley part 2444 Notch part F1 Internal fan H Heater S Water drop

Claims (1)

A refrigerant passage tube constituting a refrigerant flow path;
A heat exchange comprising: a refrigerant that is thermally connected to the refrigerant passage pipe, and a fin member that promotes heat exchange between the refrigerant that passes through the refrigerant passage pipe and the fluid that passes through the refrigerant passage pipe. In the vessel
The fin member is formed with a plurality of cut-and-raised portions on the surface, and a shall be formed notch between the cut-and-raised portions adjacent to each other, the angle of attack of the cut-and-raised portion θ is 20 ° ~ 29 ° And the distance δL along the surface direction of the fin member between the adjacent cut-and-raised portions when the maximum height of the cut-and-raised portion is a and the thickness of the fin member is t The heat exchanger according to claim 1, wherein the expression is satisfied.
(Formula) δL> (2a + t) · tan θ (however, 20 ° ≦ θ ≦ 29 °)

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