Patent Application
20150053377
The present invention relates to a heat exchanger equipped with heat transfer tubes and fins, and a heat exchanger manufacturing method.
Conventionally, a fin-and-tube type heat exchanger has been known as a heat exchanger (for example, see Patent Literature 1). The heat exchanger is configured such that, with respect to a plurality of fins arranged in parallel with a certain distance therebetween, a plurality of heat transfer tubes are inserted into the assembling holes formed in the fins, and the tubes are expanded. Here, the outer peripheral surfaces of the heat transfer tubes are applied with adhesive resin, with which the heat transfer tubes and the fins are fixedly attached.
However, in the heat exchanger described in Patent Literature 1, when the heat transfer tube is inserted into the assembling hole, the heat transfer tube and the assembling hole may be brought into contact with each other so that the adhesive resin applied to the heat transfer tube may be peeled. In that case, the adhesion between the heat transfer tube and the fin is deteriorated, which results in lowering of their heat-transfer coefficient.
In view of the above, an object of the present invention is to provide a heat exchanger and a heat exchanger manufacturing method capable of preventing peeling of adhesive and preventing deterioration in adhesion between heat transfer tubes and a fin.
According to an aspect of the present invention, a heat exchanger includes: a heat transfer tube; a plurality of fins that includes ark-shaped contact surfaces configured to be brought into contact with an outer peripheral surface of the heat transfer tube and are attached from an outside in a radial direction of the heat transfer tube; and an adhesive that bonds the outer peripheral surface of the heat transfer tube and the contact surface of each of the fins.
According to this configuration, the fin can be bonded to the heat transfer tubes from the outside in a radial direction of the heat transfer tube. As a result, as the heat transfer tubes are not inserted into the fin, peeling of the adhesive due to insertion can be avoided, whereby it is possible to prevent deterioration in adhesion between the heat transfer tube and the fin. Thereby, it is possible to prevent lowering of the heat-transfer coefficient between the heat transfer tube and the fin.
Advantageously, in the heat exchanger, the plurality of the fins include a pair of the fins disposed adjacently between which the heat transfer tube is interposed, in an orthogonal plane orthogonal to the tube axis direction of the heat transfer tube, and assuming, on the orthogonal plane, that a direction in which the pair of the fins are adjacent to each other is a width direction and that a direction orthogonal to the width direction is a length direction, one of the pair of fins and the other one of the pair of fins are disposed by being shifted in position in at least one direction of the tube axis direction and the length direction.
According to this configuration, by setting an end portion in the length direction of one fin and an end portion in the length direction of the other fin at different positions in the length direction, a difference in level is formed. Similarly, by setting one fin and the other fin at different positions in the tube axis direction, a difference in level is formed. As a result, with the formed differences in level, it is possible to cause the fluid flowing around the difference in level to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient can be improved.
Advantageously, in the heat exchanger, the plurality of the fins include a pair of the fins disposed adjacently between which the heat transfer tube is interposed, in the orthogonal plane orthogonal to the tube axis direction of the heat transfer tube, and assuming, on the orthogonal plane, that a direction in which the pair of the fins are adjacent to each other is a width direction and that a direction orthogonal to the width direction is a length direction, one of the pair of fins and the other one of the pair of fins are configured such that end portions in the width direction, which are adjacent to each other, overlap each other in the tube axis direction.
According to this configuration, a portion of one fin and a portion of the other fin can be overlapped. As such, with the overlapped portion, it is possible to cause the fluid flowing around the overlapped portion to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient can be improved.
Advantageously, in the heat exchanger, the plurality of the fins include a pair of the fins disposed adjacently between which the heat transfer tube is interposed, in an orthogonal plane orthogonal to the tube axis direction of the heat transfer tube, and assuming, on the orthogonal plane, that a direction in which the pair of the fins are adjacent to each other is a width direction and that a direction orthogonal to the width direction is a length direction, one of the pair of fins and the other one of the pair of fins are configured such that in the orthogonal plane, end portions in the width direction, which are adjacent to each other, face each other with a predetermined clearance gap.
According to this configuration, a clearance gap can be formed between one fin and the other fin. As a result, with the clearance gap, it is possible to cause the fluid flowing around the clearance gap to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient can be improved.
Advantageously, in the heat exchanger, the plurality of the fins are disposed at predetermined intervals in the tube axis direction of the heat transfer tube, and the heat exchanger further includes a position regulation portion provided between the fins adjacent to each other in the tube axis direction, the position regulation portion regulating a position in the tube axis direction of each of the fins.
According to this configuration, as the position in the tube axis direction of the fin can be regulated by the position regulation portion, resistant to earthquakes can be improved.
Advantageously, in the heat exchanger, the position regulation portion is formed of the adhesive.
According to this configuration, as the position regulation portion can be formed using the adhesive, bonding of the heat transfer tube and the fin and positional regulation of the fin can be performed. As a result, the adhesive can be utilized effectively.
According to another aspect of the present invention, a heat exchanger manufacturing method includes: a fin disposing step for disposing a plurality of fins at predetermined intervals in a tube axis direction of a heat transfer tube, each of the fins having ark-shaped contact surfaces configured to be brought into contact with an outer peripheral surface of the heat transfer tube; an adhesive applying step for applying an adhesive to at least one of the outer peripheral surface of the heat transfer tube and the contact surface of each of the fins; and a bonding step for bonding the plurality of the fins from an outside in a radial direction of the heat transfer tube.
According to this configuration, the fin can be bonded to the heat transfer tubes from the outside in a radial direction of the heat transfer tube. As a result, as the heat transfer tubes are not inserted into the fin, peeling of the adhesive due to insertion can be avoided, whereby it is possible to prevent deterioration in adhesion between the heat transfer tube and the fin. Thereby, it is possible to prevent lowering of the heat-transfer coefficient between the heat transfer tube and the fin.
Advantageously, in the heat exchanger manufacturing method, the adhesive applying step includes applying the adhesive to the outer peripheral surface of the heat transfer tube.
According to this configuration, as it is only necessary to apply the adhesive only to the heat transfer tube, the adhesive can be applied easily. In this case, it is effective for a heat exchanger in which the interval between the fins is narrow.
Advantageously, in the heat exchanger manufacturing method, the adhesive applying step includes applying the adhesive to the contact surface of each of the fins.
According to this configuration, as the adhesive is not applied to an unnecessary portion where the heat transfer tube and the fin are not brought into contact with each other, it is possible to prevent an increase in contact thermal resistance caused by application of the adhesive to the unnecessary portion.
Hereinafter, embodiments of the present invention will be described in detail based on the drawings. It should be noted that the invention is not limited by those embodiments. Further, the constituent elements in the embodiments described below include those easily replaceable by those skilled in the art or those which are substantially the same.
A heat exchanger 1 of the first embodiment is an air-cooled heat exchanger, and is a large heat exchanger to be installed in a large-scale plant such as a power plant. The heat exchanger 1 includes heat transfer tubes 10 through which a heat medium flows, and a plurality of fins 11 bonded to the heat transfer tubes 10.
The heat transfer tubes 10 are formed using a copper tube having high heat conductivity, for example, and a plurality of heat transfer tubes 10 are disposed in a row in a predetermined direction on a cross section orthogonal to the tube axis direction (orthogonal plane). It should be noted that the heat transfer tubes 10 may be linked at end portions in the tube axis direction with use of a U-shaped pipe or the like to thereby constitute a long serpentine heat transfer tube. Further, the heat transfer tubes 10 may be linked, at the end portions in the tube axis direction thereof, to a header through which a heat medium flows, but they are not limited thereto.
The fins 11 are configured such that each of the fins 11 is formed in a plate shape, and the fins 11 are stacked in the tube axis direction of the heat transfer tube 10. Specifically, the fins 11 are arranged such that a pair of them is disposed on both sides in a radial direction between which the heat transfer tubes 10 are interposed, and pairs of the fins 11 are arranged in parallel at predetermined intervals in the tube axis direction. As such, the tube axis direction of the heat transfer tubes 10 and the stacked direction of the fins 11 are in the same direction.
Here, as shown in
Each of the plate-like fins 11 is made of aluminum, aluminum alloy, or the like, and a longer side extending in the length direction on the heat transfer tube 10 side in the width direction has a plurality of holding grooves 15, formed at predetermined intervals, for holding the heat transfer tubes 10. As shown in
Further, as shown in
Further, as shown in
Between the outer peripheral surface of the heat transfer tube 10 and the contact surface 17 of the fin 11, an adhesive 21 is provided. This means that the outer peripheral surface of the heat transfer tube 10 and the contact surface 17 of the fin 11 are bonded with the adhesive 21. As the adhesive 21, various types of adhesive such as silicon-based, urethane-based, epoxy-based, or polyimide-based adhesive can be used, for example. Further, it is preferable to use the adhesive 21 having high heat conductivity. For example, a mixture of the adhesive and a metallic material is used.
As shown in
Next, a manufacturing method for manufacturing the heat exchanger 1 will be described with reference to
Then, the adhesive 21 is applied to the outer peripheral surface of the heat transfer tube 10 (S12: adhesive applying step). Here, in the adhesive applying step S12, the adhesive 21 is applied uniformly to the outer peripheral surface of the heat transfer tube 10 so as to have a predetermined thickness which enables the position regulation portion 22 to be formed.
Then, the outer peripheral surface of the heat transfer tube 10, on which the adhesive 21 is applied, and the stacked fins 11 on the one side are bonded from the outside in the radial direction of the heat transfer tube 10. Similarly, the outer peripheral surface of the heat transfer tube 10, on which the adhesive 21 is applied, and the stacked fins 11 on the other side are bonded from the outside in the radial direction of the heat transfer tube 10 (S13: bonding step). Here, in the bonding step S13, bonding may be performed by pressing the contact surfaces 17 of the fin 11 against the outer peripheral surfaces of the heat transfer tubes 10, or bonding may be performed by pressing the outer peripheral surfaces of the heat transfer tubes 10 against the contact surfaces 17 of the fin 11. Further, the fin 11 may be bonded in a state where the heat transfer tube 10 is erected such that the tube axis direction is in a vertical direction, or the fin 11 may be bonded in a state where the heat transfer tube 10 is laid such that the tube axis direction is in a horizontal position. Then, in the bonding step S13, by bonding the heat transfer tubes 10 and the fin 11, the adhesive 21 between the fins 11 is swollen, whereby the position regulation portion 22 is formed.
As described above, according to the configuration of the first embodiment, the fin 11 can be bonded to the heat transfer tubes 10 from the outside in the radial direction of the heat transfer tube 10. As a result, as the heat transfer tubes 10 are not inserted into the fin 11, peeling of the adhesive 21 due to insertion can be avoided, whereby it is possible to prevent deterioration in adhesion between the heat transfer tube 10 and the fin 11. Thereby, it is possible to prevent lowering of the heat-transfer coefficient between the heat transfer tube 10 and the fin 11.
Further, according to the configuration of the first embodiment, by setting an end portion in the length direction of one fin 11 and an end portion in the length direction of the other fin 11 at different positions in the length direction, a difference in level can be formed. As a result, with the formed difference in level, it is possible to cause the fluid flowing around the difference in level to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient of the heat exchanger 1 can be improved.
Further, according to the configuration of the first embodiment, as the position in the tube axis direction of the fin 11 can be regulated by the position regulation portion 22, resistant to earthquakes can be improved. This is particularly effective for the heat exchanger 1 in a large size.
Further, according to the configuration of the first embodiment, as the position regulation portion 22 can be formed using the adhesive 21, bonding of the heat transfer tube 10 and the fin 11 as well as positional regulation of the fin 11 can be performed. As a result, the adhesive 21 can be utilized effectively.
Further, according to the configuration of the first embodiment, as it is only necessary to apply the adhesive 21 only to the heat transfer tubes 10, the adhesive 21 can be applied easily.
It should be noted that while in the first embodiment the position regulation portion 22 is formed by bonding the heat transfer tubes 10 and the fin 11 and swelling the adhesive 21, the position regulation portion 22 may be formed by applying the adhesive 21 between the fins 11 after the heat transfer tubes 10 and the fin 11 are bonded.
Further, while in the first embodiment the adhesive 21 is applied to the outer peripheral surface of the heat transfer tube 10, the adhesive 21 may be applied to the contact surface 17 of the fin 11. According to this configuration, as the adhesive 21 is not applied to an unnecessary portion where the heat transfer tube 10 and the fin 11 are not brought into contact with each other, it is possible to prevent an increase in contact thermal resistance caused by application of the adhesive 21 to the unnecessary portion.
Next, a heat exchanger 30 according to a second embodiment will be described with reference to
As shown in
As described above, according to the configuration of the second embodiment, the one fin 11 and the other fin 11 are located at different positions in the tube axis direction so as to be in a stepped state, whereby a clearance gap is formed. As a result, with the formed clearance gap, it is possible to cause the fluid flowing around the clearance gap to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient of the heat exchanger 30 can be improved.
Next, a heat exchanger 40 according to a third embodiment will be described with reference to
As shown in
Specifically, as shown in
Further, as shown in
As described above, according to the configuration of the third embodiment, portions of the one fin 41 and the other fin 41 can be overlapped. As a result, with the overlapped portion, it is possible to cause the fluid flowing around the overlapped portion to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient of the heat exchanger 40 can be improved.
Next, a heat exchanger 50 according to a fourth embodiment will be described with reference to
As shown in
Specifically, as shown in
Further, as shown in
As described above, according to the configuration of the fourth embodiment, a clearance gap can be formed between the one fin 51 and the other fin 51. As a result, with the clearance gap, it is possible to cause the fluid flowing around the clearance gap to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient of the heat exchanger 50 can be improved.
Next, a heat exchanger 60 according to a fifth embodiment will be described with reference to
As shown in
As described above, according to the configuration of the fifth embodiment, the one fin 51 and the other fin 51 are located at different positions in the tube axis direction so as to be in a stepped state, whereby a clearance gap is formed. As a result, with the formed clearance gap, it is possible to cause the fluid flowing around the clearance gap to be a turbulent flow, which promotes heat exchange. Thereby, the heat-transfer coefficient of the heat exchanger 60 can be improved.
It should be noted that while, in the second to fifth embodiments, the fins 11, 41, 51 on one side and the fins 11, 41, 51 on the other side are shifted in position in the length direction, in that case, the fin 11 on the one side and the fin 11 on the other side may be at the same position in the length direction, or may be at different positions, in other words, they are not limited thereto. Further, the heat exchangers 1, 30, 40, 50, and 60 described in the first embodiment to the fifth embodiment may be combined appropriately.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-174914 | Aug 2013 | JP | national |
