JP5523400B2 - Heat exchanger and air conditioner equipped with the heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger and an air conditioner equipped with the heat exchanger.

  Conventionally, a plurality of fins in which notches into which flat heat transfer tubes are inserted are arranged in a comb-like shape in the longitudinal direction are stacked with a gap through which air passes, and flat heat transfer tubes are inserted into the notches of these fins A heat exchanger in which a working fluid passes through a flat heat transfer tube is known.

  In such a thing, the width of the notch of the fin is set so as to be narrower than that of the flat heat transfer tube in consideration of adhesion to the flat heat transfer tube inserted therein. For this reason, the radius of the end arc of the notch is also smaller than the radius of the end arc of the flat heat transfer tube inserted into the notch. Accordingly, when the flat heat transfer tube is fitted into the notch of the fin, the opening side of the notch is pushed open by the flat heat transfer tube, and the fin is warped. This warp increases as the flat heat transfer tube is pushed into the notch end arc. This seems to be due to the wedge effect when pushing in the flat heat transfer tube. When the fin is warped, the interval between the flat heat transfer tubes is disturbed, which causes troubles in brazing of the piping for connection and housing of the unit. Furthermore, the adhesiveness between the tube and the fin is deteriorated, and the heat transfer performance is lowered.

  Conventionally, such a problem has been dealt with by increasing the rigidity of the fin by providing a bead for increasing the strength on the side of the fin not having a notch (for example, see Patent Documents 1 and 2).

JP 2008-002746 A (FIG. 3) Japanese Utility Model Publication No. 5-090173 (FIG. 2)

  As described above, the conventional heat exchanger copes with the warping of the fin that occurs when the opening side of the notch is pushed open by the flat heat transfer tube by increasing the rigidity of the fin, and suppresses the occurrence of the warping itself. It wasn't something to do.

  The technical problem of the present invention is to be able to suppress the warpage itself that occurs when the opening side of the notch is pushed open by a flat heat transfer tube.

  A heat exchanger according to the present invention has a flat heat transfer tube through which a working fluid passes and fins in which notches are juxtaposed in a comb-like shape in the longitudinal direction, and the fins are stacked with a gap. In the heat exchanger in which the flat heat transfer tubes are fitted, the notches are formed so that the notches on both ends are deeper than the center portion in the fin longitudinal direction.

  In the heat exchanger according to the present invention, since the depth of the notches on both end sides is deeper than the center portion in the fin longitudinal direction, the flat transmission fitted into the notches on both end sides in the fin longitudinal direction. A play can be provided between the insertion tip of the heat tube and the end arc of the notch, and accordingly, the pushing pressure of the flat heat transfer tube against the notch on both ends of the fin in the longitudinal direction can be reduced. . For this reason, it is possible to suppress the warping itself that occurs when the opening side of each notch is pushed open by a flat heat transfer tube, improving the mounting properties and heat transfer performance of piping parts, and taking into account deformation during unit storage The wasted space can be eliminated.

It is a perspective view which shows the external appearance of the principal part of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the relationship between the fin of the heat exchanger which concerns on Embodiment 1 of this invention, and a flat heat exchanger tube. It is sectional drawing which shows the relationship between the fin of the heat exchanger of a comparative example, and a flat heat exchanger tube. It is a refrigerant circuit figure of the refrigerating cycle of the air conditioner concerning Embodiment 2 of the present invention.

Embodiment 1. FIG.
FIG. 1 is a perspective view showing the appearance of the main part of a heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view showing the relationship between the fins and flat heat transfer tubes.
The heat exchanger 10 according to Embodiment 1 of the present invention includes rectangular fins 2 stacked in a plurality of gaps through which air passes as shown in FIGS. 1 and 2, and orthogonal to each of these fins 2. A flat heat transfer tube 1 through which the working fluid passes is provided.

  More specifically, the fin 2 is provided with a notch 2a into which the flat heat transfer tube 1 is fitted in a comb-like shape in the longitudinal direction. The width of the opening 2b of the notch 2a is set so as to be narrower than that of the flat heat transfer tube 1 in consideration of adhesiveness with the flat heat transfer tube 1 fitted therein. Further, as shown in FIG. 2, the notch 2a is configured such that the envelope A1 formed by connecting the respective end arcs 2c draws an arc in which the notch forming side of the fin 2 is convex. Thereby, the depth of the notch 2a increases smoothly from the center in the fin longitudinal direction toward both ends. However, the depth of the predetermined number of notches 2a existing in the center may be the same.

FIG. 3 is a sectional view showing the relationship between the fins of the heat exchanger of the comparative example and the flat heat transfer tubes.
The fins (hereinafter referred to as “test fins”) 3 of the heat exchanger of this comparative example are conventional fins (the depth of each notch is the same as the depth of the notch at the center in the longitudinal direction of the fin). Are the same). When the flat heat transfer tube 1 is inserted into each notch 3a of such a test fin 3 and inserted to the end arc 3c, the opening 3b side of each notch 3a is pushed open by the flat heat transfer tube 1 as described above. As a result, the test fin 3 warps A2. The curvature of the arc drawn by the envelope A1 is set according to the curvature of the warp A2 generated in the test fin 3. Here, the curvature of the arc drawn by the envelope A1 is set so that the amount of warpage of the arc drawn by the envelope A1 becomes half the amount of warpage B1 of the warp B2 of the test fin 3. Thereby, it is easy to secure the width of the connecting portion on the opposite side of the fin 2.

  Next, the fin warpage suppression principle of the heat exchanger according to the first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3, the flat heat transfer tube 1 is fitted into each notch 3a of the second test fin 3 (or flat) in a state where the warping A2 is generated in the first fin, that is, the test fin 3. When the second test fin 3 is inserted into the heat transfer tube 1), the flat heat transfer tubes 1 positioned at both ends, which are positioned higher due to warpage of the first test fin 3, are used for the second test. It fits in the notch 3a located in the both ends of the fin 3. FIG. Then, from this state, the flat heat transfer tubes 1 located at both ends are inserted to the end arcs 3c of the notches 3a located at both ends of the second test fin 3, but the flat heat transfer tubes 1 located at both ends are inserted. Is inserted into the notch 3c of the notch 3a located at both ends of the second test fin 3, and the flat heat transfer tube 1 is inserted later into the notch 3a in the center of the second test fin 3. Since it is in the lower position, it only fits in the middle of the notch 3a at the center of the second test fin 3. Therefore, the center portion of the second test fin 3 in the longitudinal direction is forcibly pressed against the flat heat transfer tube 1 side, and the flat transfer is made to the end arc 3c of the notch 3a in the center portion of the second test fin 3. The heat pipe 1 must be inserted, and the warpage is further deteriorated.

  Next, as shown in FIG. 3, with the warping A2 occurring in the first fin, ie, the test fin 3, the fin 2 of the heat exchanger according to the first embodiment of the present invention is used as the second fin. The case where the flat heat transfer tube 1 is inserted into each notch 2a (or the second fin 2 is inserted into the flat heat transfer tube 1) will be considered. Also in this case, first, the flat heat transfer tubes 1 positioned at both ends which have become high due to warpage of the first test fin 3 are fitted into the notches 2 a positioned at both ends of the second fin 2. Then, from this state, the flat heat transfer tubes 1 positioned at both ends are inserted to the end arc 2c of the notch 2a positioned at both ends of the second fin 2. In this case, each notch 2a of the second fin 2 is configured such that the envelope A1 formed by connecting the respective terminal arcs 2c draws an arc in which the notch forming side of the fin 2 is convex. As a result, the depth of the notch 2a is configured to be smoothly deepened from the center in the longitudinal direction of the fin toward both ends, so that these flat heat transfer tubes 1 are disposed at both ends of the second fin 2 If it inserts to the end circular arc 2c of the notch 2a located, the flat heat exchanger tube 1 inserted afterwards into the notch 2a of the center part of the 2nd fin 2 will also be inserted to the terminal circular arc 2c of the notch 2a. Therefore, it is not necessary to force the second fin 2 to be pressed against the flat heat transfer tube 1 side, and further deterioration of warpage can be prevented.

  The above describes the advantages of using the fin 2 of the heat exchanger according to the first embodiment of the present invention as the second and subsequent fins. Since the depth of each notch is the same as the depth of the notch at the center in the fin longitudinal direction), the occurrence of warpage A2 cannot be suppressed.

  By using the fin 2 of the heat exchanger according to the first embodiment of the present invention from the first sheet, the fin 2 can effectively act and suppress warpage. That is, since the fin 2 is formed so that the depth of the notch 2a at both ends is deeper than the center portion in the fin longitudinal direction, the flat heat transfer tube 1 fitted into the notch 2a at both ends in the fin longitudinal direction. Play can be provided between the insertion end of the flat plate and the end arc of the notch, and accordingly, the pushing pressure of the flat heat transfer tube 1 against the notch 2a on both ends of the fin in the longitudinal direction can be reduced. it can. For this reason, it is possible to suppress the warping itself that occurs when the opening 2b of each notch 2a is pushed open by the flat heat transfer tube 1, and the mounting property and heat transfer performance of the piping parts are improved. It is possible to eliminate a useless space in consideration of deformation.

  Further, the notch 2a is configured such that the envelope A1 formed by connecting the respective end arcs 2c draws an arc in which the notch forming side of the fin 2 is convex, and the depth of the notch 2a is thereby increased. The depths of the notches 2a on both ends in the fin longitudinal direction can be optimized by smoothly increasing the depth from the center in the fin longitudinal direction toward both ends. Thereby, even if a gap is generated between the end arc 2c of the notch 2a and the insertion tip of the flat heat transfer tube 1, this can be made as small as possible to improve the heat transfer performance. Can do.

Embodiment 2. FIG.
FIG. 4 is a refrigerant circuit diagram of a refrigeration cycle of an air conditioner according to Embodiment 2 of the present invention including the above-described heat exchanger.

As shown in FIG. 4, the air conditioner according to the second embodiment of the present invention includes a compressor 33, a condenser 34, a throttling device 35, an evaporator 36, a condenser blower 37a and its driving motor 38a, an evaporator blower 37b, and The compressor 33, the condenser 34, the expansion device 35, and the evaporator 36 are connected in a ring shape. By using the heat exchanger according to the first embodiment for the condenser 34, the evaporator 36, or both, an air-conditioning refrigeration apparatus with high energy efficiency can be realized. Here, energy efficiency is calculated | required by following Formula (1) (2).
Heating energy efficiency = indoor heat exchanger (condenser) capacity / all inputs (1)
Cooling energy efficiency = indoor heat exchanger (evaporator) capacity / all inputs (2)

  In addition, about the heat exchanger described in above-mentioned Embodiment 1, and an air conditioner provided with this heat exchanger, HCFC (R22) and HFC (R116, R125, R134a, R14, R143a, R152a, R227ea, R23, R236ea, R236fa, R245ca, R245fa, R32, R41, RC318, etc., and several types of these refrigerants R407A, R407B, R407C, R407D, R407E, R410A, R410B, R404A, R507A, R508A, HCB, etc. Low GWP refrigerants such as butane, isobutane, ethane, propane, propylene, etc., some mixed refrigerants of these refrigerants, natural refrigerants (air, carbon dioxide, ammonia, etc., several mixed refrigerants of these refrigerants), HFO1234yf, These refrigerants A mixed refrigerant type, be used any type of refrigerant, can achieve its effect.

  Moreover, although the example of air and a refrigerant | coolant was shown here as a working fluid, even if it uses other gas, liquid, and gas-liquid mixed fluid, there exists the same effect.

  The flat heat transfer tubes 1 and the fins 2 are generally made of different materials. However, it is possible to braze the fins 2 and the flat heat transfer tubes 1 by using the same material such as copper or aluminum as the material of the flat heat transfer tubes 1 and the fins 2. In this case, the contact heat transfer coefficient between the fin 2 and the flat heat transfer tube 1 is dramatically improved, and the heat exchange capability is greatly improved. Moreover, recyclability can also be improved.

  Further, as a method of bringing the flat heat transfer tube 1 and the fin 2 into close contact, when brazing in the furnace, if the hydrophilic material is applied to the fin 2 after brazing in the furnace, the burning of the hydrophilic material is prevented. be able to.

  Further, the same effect can be obtained when the heat exchanger described in the first embodiment is used in an outdoor unit.

  For the heat exchanger described in the first embodiment and the air-conditioning refrigeration apparatus of the second embodiment using the heat exchanger, a mineral oil, an alkylbenzene oil, an ester oil, an ether oil, a fluorine oil, The effect can be achieved with any refrigeration oil, regardless of whether the oil is soluble or not.

  1 flat heat transfer tube, 2, 3 fin, 2a, 3a notch, 2b, 3b opening, 2c, 3c end arc, 3 test fin, 10 heat exchanger, 33 compressor, 34 condenser, 35 expansion device, 36 Evaporator, 37a Condenser blower, 37b Evaporator blower, 38a, 38b Drive motor, A1 envelope, A2 warp, B1 Warp amount of arc drawn by envelope, B2 Warp amount of conventional fin.

Claims (5)

It has a flat heat transfer tube through which the working fluid passes, and fins in which notches are arranged in a comb-like shape in the longitudinal direction, and a plurality of the fins are stacked with a gap therebetween. Is a heat exchanger in which the flat heat transfer tube is inserted,
A heat exchanger characterized in that the depth of the notch on both end sides becomes deeper than the center portion in the fin longitudinal direction.   The heat exchanger according to claim 1, wherein the depth of the notch becomes deeper from the center in the longitudinal direction of the fin toward both ends.   The said notch is comprised so that the envelope formed by connecting each terminal circular arc may draw the circular arc from which the notch formation side of the said fin becomes convex. The described heat exchanger.   The curvature of the arc drawn by the envelope is such that the depth of each notch is the same as the depth of the notch in the central portion in the longitudinal direction of the fin when the flat heat transfer tube is fitted into the test fin. The heat exchanger according to claim 3, wherein the heat exchanger is set according to a curvature of a warp to be generated. In an air conditioner in which a compressor, a condenser, a throttling device, and an evaporator are connected in an annular shape,
An air conditioner using a refrigerant as a working fluid and using the heat exchanger according to any one of claims 1 to 4 for both or one of the evaporator and the condenser.

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