JP2014020580A - Fin tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fin tube type heat exchanger with an improved heat transfer performance.SOLUTION: The fin tube type heat exchanger comprises: plural heat transfer fins 2 that are parallely aligned at predetermined intervals, and between which gas flows; plural heat transfer pipes 3 that are almost orthogonally inserted in the heat transfer fins 2 and penetrate through them, and inside which fluid flows; almost cylindrical fin collars 4 extending in a direction almost orthogonal to a plane direction of the heat transfer fins 2. The heat transfer fin 2 is formed in such a waved shape that crest parts 5 and valley parts 6 are alternately continued, and height (H) of at least one crest part 5 is set larger than a distance (L) between the two adjacent heat transfer fins 2 and smaller than twice of the distance (L). Notches 7 are provided on the heat transfer fins 2, and the heat transfer fin 2 on a windward side of the notch 7 on which gas flows is indented. A valley part 9 having an opening 8 formed by the notch 7 is formed on a leeward side. Fluid passes through a wave-shaped part formed by the crest parts 5 and the valley parts 6, which can contribute to thin a temperature boundary layer on a surface of the heat transfer fin 2.

Description

  The present invention is used in air conditioners such as room air conditioners, packaged air conditioners, and car air conditioners, heat pump hot water heaters, refrigerators, freezers, etc., and a plurality of heat transfer fins and gases flowing between heat transfer fins are used. The present invention relates to a finned tube heat exchanger that transfers heat between a fluid and a fluid such as water or a refrigerant flowing in a heat transfer tube.

  As conventional fin tube type heat exchangers, there are those shown in FIGS. 7 to 11 (see, for example, Patent Document 1).

  7 is a perspective view of the conventional finned tube heat exchanger described in Patent Document 1, FIG. 8 is a front view of the fin of the finned tube heat exchanger, and FIG. 9 is a bottom view of the fin. FIG. 10 is an enlarged perspective view of a main part of the fin, and FIG. 11 is an enlarged perspective view of another main part of the fin.

  In general, as shown in FIG. 7, a finned tube heat exchanger composed of a large number of laminated flat plate heat transfer fins and heat transfer tubes is stacked in parallel at a constant pitch, and air or the like between them. A large number of flat plate-like heat transfer fins 101 through which the gas W flows, and heat transfer tubes 104 inserted into the heat transfer fins 101 at a predetermined pitch at a substantially right angle and in which a fluid R such as water or refrigerant flows. The heat transfer tube 104 is tightly joined to a circumferential fin collar 102 raised vertically to the outer periphery of a through hole (not shown) of the heat transfer fin 101. Further, the heat transfer fin 101 has a triangular delta that is formed by providing two slits as shown in FIGS. 8, 9, 10, and 11 in the slit forming portion 103 to cut one side as a basic line. Cut and raised pieces 111 and 112 called wings are provided.

  As shown in FIGS. 10 and 11, the cut-and-raised pieces 111 and 112 of the conventional fin tube heat exchanger are gradually narrowed from the base portion toward the tip portion, and a vertical vortex S is generated in the passing air. The blade part to be made is cut and raised from the heat transfer fin 101. This longitudinal vortex S improves the heat transfer coefficient (see, for example, Patent Document 1).

  In addition, as shown in FIG. 12, the heat transfer fin 201 is provided with cuts 202, and the heat transfer fin portion on the windward side is raised in the gas flow direction 203, and a valley portion 205 having an opening 204 on the leeward side is formed. The fin tube type heat exchanger to form is also proposed (for example, refer patent document 2).

Japanese Patent Laid-Open No. 2005-207688 JP 2010-8034 A

  However, in the configuration of the fin tube type heat exchanger as described in Patent Documents 1 and 2, the ventilation resistance of the cut-and-raised shape portion is large with respect to the ventilation resistance of the flat plate-shaped heat transfer fin portion. The fluid flows so as to bypass the cut-and-raised shape, and there is a problem that the heat exchange performance is not improved for the increase in the overall ventilation resistance.

The present invention solves the above-mentioned conventional problems, and provides a finned-tube heat exchanger that prevents heat flow detours due to ventilation resistance of cut-and-raised parts in flat heat transfer fins and improves heat transfer performance The purpose is to do.

  In order to solve the above-described conventional problems, a finned tube heat exchanger according to the present invention is arranged in parallel at predetermined intervals, and a plurality of heat transfer fins through which gas flows, and substantially perpendicular to the heat transfer fins. A plurality of heat transfer tubes through which a fluid flows, and a substantially cylindrical fin collar extending in a direction substantially orthogonal to the plane direction of the heat transfer fins, The crests and troughs are alternately formed in a wave shape, and at least one height (H) of the crests is larger than the distance (L) between two adjacent heat transfer fins, and this distance (L) is a finned tube heat exchanger set smaller than twice, wherein the heat transfer fin is provided with a cut, and the heat transfer fin on the windward side where the gas flows in the cut is depressed, and the leeward side Formed by the incision The heat transfer fin has a peak portion and a valley portion, so that the surface area of the heat transfer fin itself increases and the fluid flows between the peak portion and the valley portion of the heat transfer fin. By passing through the formed continuous wave shape, it is possible to contribute to the thinning of the temperature boundary layer on the surface of the heat transfer fin.

  Moreover, since the inclination of the valley portion having the opening formed by the cut on the leeward side is less inclined than the slope of the peak portion of the heat transfer fin, it is possible to keep the ventilation resistance low. Further, when the gas passes through the opening formed by this cutting, a vertical vortex is generated, and the temperature boundary layer on the surface of the heat transfer fin is disturbed. By doing so, there is an effect of improving the heat transfer performance of the heat exchanger by improving the heat transfer coefficient of the heat transfer fins while suppressing an increase in ventilation resistance.

  In the finned tube heat exchanger of the present invention, the heat transfer fin has a peak portion and a valley portion, so that the surface area of the heat transfer fin itself increases and the fluid is formed by the peak portion and the valley portion of the heat transfer fin. By passing through the continuous wave shape, it is possible to contribute to the thinning of the temperature boundary layer on the surface of the heat transfer fin.

The perspective view of the fin tube type heat exchanger in Embodiment 1 of this invention Figure 1 View from the direction of arrow A Partial enlarged view of FIG. The figure which shows the flow direction of the gas of the fin tube type heat exchanger The perspective view of the finned-tube type heat exchanger in Embodiment 2 of this invention The perspective view of the fin tube type heat exchanger in Embodiment 3 of this invention A perspective view of a conventional finned tube heat exchanger Front view of fin of same finned tube heat exchanger Bottom view of the fin Enlarged perspective view of the main part of the fin An enlarged perspective view of another main part of the fin Front view of heat transfer fins of another conventional finned tube heat exchanger

The first invention is a plurality of heat transfer fins that are arranged in parallel at predetermined intervals and between which a gas flows, and a plurality of heat transfer fins that are inserted through the heat transfer fins at substantially right angles and through which the fluid flows. A heat transfer tube and a substantially cylindrical fin collar extending in a direction substantially orthogonal to the planar direction of the heat transfer fin, and the heat transfer fin is formed in a wave shape in which peaks and troughs are alternately continued. The fin tube type heat exchange in which at least one height (H) of the peak portion is set larger than the distance (L) between the two adjacent heat transfer fins and smaller than twice this distance (L). The heat transfer fin is provided with a cut, and the heat transfer fin on the windward side where the gas of the cut flows is depressed to form a trough having an opening formed by the cut on the leeward side. With heat transfer fins The surface area of the heat transfer fin itself is increased, and the temperature of the surface of the heat transfer fin is increased by the fluid passing through the continuous wave shape formed by the peak and valley portions of the heat transfer fin. It can contribute to the thinning of the boundary layer.

  Moreover, since the inclination of the valley portion having the opening formed by the cut on the leeward side is less inclined than the slope of the peak portion of the heat transfer fin, it is possible to keep the ventilation resistance low. Further, when the gas passes through the opening formed by this cutting, a vertical vortex is generated, and the temperature boundary layer on the surface of the heat transfer fin is disturbed. By doing so, there is an effect of improving the heat transfer performance of the heat exchanger by improving the heat transfer coefficient of the heat transfer fins while suppressing an increase in ventilation resistance.

  In the second invention, in particular, the cutting direction of the first invention is a step direction that is substantially perpendicular to the gas flow direction, and the heat conduction direction of the heat transfer fin is substantially the cutting direction in the step direction. Therefore, the heat conduction in the step direction is not interrupted by the cut. By doing so, it is possible to suppress the generation of heat transfer fin regions that do not contribute to heat transfer, and to sufficiently exhibit excellent heat exchange performance.

  In the third aspect of the invention, in particular, the shape of the opening of the first or second aspect of the invention is a substantially triangular shape, and a valley having a substantially triangular shaped opening on the leeward side has a vertical vortex in the wake. Two rising triangle pieces called delta wings that generate heat and promote heat transfer face each other and are connected by the ridges of the ridge line from the summit to the foot of the mountain. That is, after the gas flows along the slope of the valley, when it passes through the opening on the leeward side, a vertical vortex is generated in the same manner as the delta wing, disturbing the temperature boundary layer on the surface of the heat transfer fin on the leeward side. Become. By doing so, the heat transfer coefficient of the heat transfer fin is improved.

In the finned tube heat exchanger according to any one of the first to third inventions, the fourth invention is the heat transfer between the fin collars adjacent to each other in the step direction in the valley portion having the opening on the leeward side. A plurality of fin surfaces are formed, and the heat transfer performance improvement effect by the trough having the opening on the leeward side,
It increases in proportion to the number formed. By doing so, it is possible to improve the heat transfer performance of the heat exchanger.

  In the fifth aspect of the invention, in particular, the number of valleys having openings on the leeward side of the fourth aspect of the invention is greater on the leeward side where the gas flows than on the leeward side. When using as an outdoor unit heat exchanger, frost adheres to the surface of the heat transfer fins when the outside air temperature decreases during heating operation, but according to this configuration, some of the moisture in the air is on the windward side. After the frost adheres to the heat transfer fin surface, the air with reduced moisture flows to the leeward side, so the frost that adheres to the leeward heat transfer fin surface decreases, and there are many valleys with openings on the leeward side. Even if it is provided, the growth of frost can be suppressed. By doing so, it is possible to maintain a long time until the heat transfer fins are blocked with frost, and it is possible to improve the heat transfer performance of the entire heat transfer fins.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a perspective view of a finned tube heat exchanger according to Embodiment 1 of the present invention, FIG. 2 is a view from the direction of arrow A in FIG. 1, FIG. 3 is a partially enlarged view of FIG. These are figures which show the flow direction of the gas of the fin tube type heat exchanger.

In FIG. 1, the finned tube heat exchanger according to the present embodiment includes a plurality of heat transfer fins 2 that are arranged in parallel at predetermined intervals, and between which gas flows in the direction of the flow direction 1 indicated by an arrow, A substantially cylindrical fin that is inserted into the heat transfer fin 2 at a substantially right angle, passes through, and has a large number of heat transfer tubes 3 through which fluid flows, and extends in a direction substantially perpendicular to the plane direction of the heat transfer fin 2. A collar 4 is formed.

  In FIG. 2, the heat transfer fins 2 are formed in a wave shape in which the peak portions 5 and the valley portions 6 are alternately continuous, and at least one height H of the peak portions 5 is between two adjacent heat transfer fins 2. It is comprised with the heat-transfer fin 2 which formed the peak larger than this distance L and smaller than twice this distance L.

  In FIG. 3, the heat transfer fin 2 is provided with cuts 7, the heat transfer fins 2 on the windward side in the flow direction 1 in which the gas flows with respect to the cuts 7 are depressed, and the openings formed by the cuts 7 on the leeward side. A valley portion 9 having a portion 8 is formed.

  According to this structure, the heat transfer fin 2 has the peak part 5 and the trough part 6, and the surface area of the heat transfer fin 2 itself increases.

  Moreover, in the figure which shows the flow direction of the gas of FIG. 4, gas passes through the continuous wave shape formed in the peak part 5 and the trough part 6 of the heat transfer fin 2, and the surface of the heat transfer fin 2 is shown. This contributes to thinning of the temperature boundary layer.

  Similarly, in FIG. 4, the valley portion 9 having the opening portion 8 formed by the notch 7 on the leeward side is less inclined than the gradient 10 of the peak portion 5 of the heat transfer fin 2, so that the ventilation resistance is reduced. It can be kept low.

  Further, when the gas passes through the opening 8 formed by the notches 7, a vertical vortex 11 is generated, and the temperature boundary layer on the surface of the heat transfer fin 2 is disturbed.

  By carrying out like this, there exists an effect which improves the heat transfer rate of the heat-transfer fin 2 and improves the heat exchange performance of a finned tube type heat exchanger, suppressing the increase in ventilation resistance.

  Further, in the present embodiment, as shown in FIG. 3, the direction of the cuts 7 provided in the heat transfer fins 2 is arranged so as to be in the same direction as the step direction that is substantially perpendicular to the gas flow direction 1. ing.

  According to this configuration, since the heat conduction direction of the heat transfer fins 2 is substantially along the cut direction in the step direction, the cut in the heat conduction in the step direction due to the cut 7 does not occur. By doing so, it is possible to suppress the generation of heat transfer fin regions that do not contribute to heat transfer, and to sufficiently exhibit excellent heat exchange performance.

  In the present embodiment, as shown in FIG. 3, the shape of the opening 8 is substantially triangular. According to this configuration, the valley portion 9 having the substantially triangular opening 8 on the leeward side faces two rising triangular pieces called delta wings that generate a vertical vortex 11 in the wake and promote heat transfer. It becomes a form that is connected by the ridge of the ridge line that extends from the summit to the foot of the mountain.

  That is, after the gas flows along the slope of the valley portion 9 and passes through the opening 8 on the leeward side, the vertical vortex 11 is generated as in the delta wing, and the temperature boundary of the surface of the heat transfer fin 2 on the leeward side is generated. It will disturb the layer. By doing so, the heat transfer coefficient of the heat transfer fins 2 is improved. Moreover, the same effect can be obtained when the opening shape is semicircular or trapezoidal.

(Embodiment 2)
FIG. 5 is a perspective view of the finned tube heat exchanger according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as the fin tube type heat exchanger in the said Embodiment 1, and the description is abbreviate | omitted.

  As shown in FIG. 5, the finned tube heat exchanger according to the present embodiment is configured such that the trough 9 having the leeward opening 8 is disposed between the fin collars 4 adjacent to each other in the step direction. A plurality are formed on the surface.

  According to this configuration, the effect of improving the heat transfer performance by the valley 9 having the opening 8 on the leeward side increases substantially in proportion to the number formed. By doing so, it is possible to improve the heat transfer performance of the heat exchanger.

(Embodiment 3)
FIG. 6 is a perspective view of a finned tube heat exchanger according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as the fin tube type heat exchanger in the said embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 6, the finned tube heat exchanger according to the present embodiment has the number of valleys 9 having openings 8 on the leeward side, and the leeward side in the flow direction 1 in which the gas flows is on the leeward side. More.

  When this fin tube type heat exchanger is used as a heat exchanger of an outdoor unit (not shown) of a room air conditioner, frost adheres to the surface of the heat transfer fin 2 when the outside air temperature becomes low during heating operation. According to the configuration of the finned tube heat exchanger in the embodiment, after a part of moisture in the air adheres to the surface of the heat transfer fins 2 as frost on the windward side, the air with reduced moisture moves to the leeward side. Since it flows, the amount of frost adhering to the surface of the leeward heat transfer fin 2 is reduced, and the growth of frost can be suppressed even if many valleys 9 having the leeward opening 8 are provided.

  By doing so, it is possible to maintain a long time until the heat transfer fins 2 are closed with frost, and the heat transfer performance of the heat transfer fins 2 as a whole can be improved.

  As described above, the finned tube heat exchanger according to the present invention includes a plurality of stacked heat transfer fins, a fluid such as a gas flowing between the heat transfer fins, and a fluid such as water or a refrigerant flowing in the heat transfer tube. Useful as a heat exchanger that transfers heat to and from the air-conditioner such as room air conditioners, packaged air conditioners, car air conditioners, heat pump water heaters, refrigerators, freezers, etc. It can be used.

DESCRIPTION OF SYMBOLS 1 Flow direction 2 Heat transfer fin 3 Heat transfer tube 4 Fin collar 5 Mountain part 6, 9 Valley part 7 Cut 8 Opening part 10 Gradient 11 Longitudinal vortex

Claims (5)

A plurality of heat transfer fins that are arranged in parallel at a predetermined interval and between which the gas flows, a plurality of heat transfer tubes that are inserted through the heat transfer fins at substantially right angles and through which the fluid flows, and A substantially cylindrical fin collar extending in a direction substantially perpendicular to the plane direction of the heat transfer fin, and forming the heat transfer fin in a wave shape in which peaks and valleys are alternately continuous, at least of the peaks. A fin tube heat exchanger in which one height (H) is set larger than a distance (L) between two adjacent heat transfer fins and smaller than twice this distance (L), A notch is provided in the heat transfer fin, the heat transfer fin on the windward side where the gas of the cut flows is depressed, and a trough having an opening formed by the notch is formed on the leeward side. Finned tube type heat exchange Vessel. The finned tube heat exchanger according to claim 1, wherein the direction of the cut is a step direction that is substantially perpendicular to the gas flow direction. The finned tube heat exchanger according to claim 1 or 2, wherein the shape of the opening is substantially triangular. The fin tube according to any one of claims 1 to 3, wherein a plurality of valley portions having openings on the leeward side are formed on a heat transfer fin surface between fin collars adjacent in the step direction. Mold heat exchanger. 5. The finned tube heat exchanger according to claim 4, wherein the number of valleys having openings on the leeward side is greater on the leeward side where the gas flows than on the leeward side.

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