JPS62175590A - Fin tube type heat exchanger - Google Patents

Abstract

PURPOSE:To improve heat transfer rate by a method wherein both front and rear surfaces of a plate fin is provided with a multitude of louver type raised- slotted parts at an interval between heat transfer tubes and the sides thereof are slanted with respect to airflow. CONSTITUTION:Boundary layer leading edge effect, precluding the development of temperature boundary layer, is contrived by louver type raised-slotted parts 11a-11f. Further, the sides 11g'-11e' of the raised-slotted parts are formed so as to be slanted with respect to the inflow direction of the airflow B, therefore, the airflow B collides against said sides and generates eddies whereby the improvement of heat transfer performance due to the promotion of turbulent flow may be contrived. On the other hand, the airflow B flows along the raised- slotted parts and the sides thereof and flows into the back stream side of a heat transfer tube 13 whereby dead water areas 14a, 14b at the back stream side of the heat transfer tubes 13 are reduced remarkably and heat transfer performance may be improved. The boundary layer leading edge effect, the turbulent flow promoting effect and the dead water area reducing effect may be introduced and heat transfer rate may be improved markedly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fin-tube heat exchanger used in cooling systems for air conditioners, refrigerator-freezers, vending machines, and the like.

BACKGROUND OF THE INVENTION In recent years, as equipment has become smaller and thinner, it has been desired to improve the performance of fin-tube heat exchangers, which are the main components thereof.

An example of a conventional fin-tube heat exchanger will be described below with reference to the drawings. Figure 6.

FIG. 7 shows a conventional fin-tube heat exchanger. 1
is a plate-like fin on a flat plate, fin collars 2 are raised at equal intervals, and louver-shaped cut and raised 1a, 1b, 1c are formed between the fin collars 2, and these cut and raised 1a, 1b, 1c
side parts 1d' and 1e'.

1f' is provided parallel to the airflow A. The louver-shaped cut and raised portions 1a, 11b, and 11c are for preventing a temperature boundary layer. A heat transfer tube 3 is inserted through the plate-like fin 1.

The heat exchanger tube 3 is formed in a U-shape, and both ends thereof are connected by a bend. 4a and 4b indicate dead zones formed on the downstream side of the heat transfer tubes 3. Problems to be Solved by the Invention However, in the above configuration, when the airflow A flows in the direction of the white arrow, the louver-shaped Cut and raise 1a
, 1b, 1c, the leading edge effect of the boundary layer can be expected, but the cutting and raising 1a, 1b.

Since the side portions 1 d', 1 e', and 1 f' of 1C are provided parallel to the airflow A, the effect of promoting turbulence cannot be achieved by the louver-shaped cut-and-raised portions 1a, 1b, and 1c. , Louvered cut and raised 1 a.

Even after passing through 1b and 1C, the direction of the airflow A hardly changes, resulting in a problem that the dead areas 4a and 4b generated on the downstream side of the heat transfer tube 3 are large and the heat transfer coefficient cannot be sufficiently improved.

In view of the above problems, the present invention aims at the leading edge effect of the boundary layer by cutting and raising the louver, and also aims at the effect of promoting turbulence, and by turning the airflow to the downstream side of the heat exchanger tube. The purpose of the present invention is to provide a fin-tube heat exchanger that has significantly improved heat transfer coefficient compared to the conventional one by reducing the dead area of the heat exchanger.

Means for Solving the Problems In order to solve the above problems, the fin-tube heat exchanger of the present invention includes a plurality of plate-shaped fins arranged in parallel at regular intervals and through which an air flow flows; A heat exchanger tube inserted through the fin at right angles, and a large number of louver-shaped cut and raised sections on both the front and back surfaces of the plate-shaped fin are continuously or partially formed in the space between the heat exchanger tubes of the plate-shaped fin. The louver-shaped cut-and-raised side portion is formed so as to be inclined with respect to the air flow.

Operation According to the present invention, with the above-described configuration, the leading edge effect of the boundary layer can be achieved by cutting and raising the louver, and the effect of promoting turbulence can be achieved at the side portions of the louver. At this time, if the substrate portion of the plate-like fin is partially left and cut and raised, it is possible to further enhance the leading edge effect of the boundary layer and the effect of promoting turbulent flow, and to reduce the pressure loss of the airflow. Furthermore, since the airflow flows along the louver-shaped cut-up and wraps around the wake of the heat transfer tube, the dead area can be reduced, and the heat transfer coefficient is significantly improved compared to the conventional method.

EXAMPLE Hereinafter, a fin-tube heat exchanger according to an example of the present invention will be described with reference to FIGS. 1 to 6.

1 to 3 show a first embodiment of the present invention.

Reference numeral 11 denotes a flat plate-like fin, and fin collars 12 are raised at equal intervals. 13 is a heat exchanger tube, and the plate-shaped fin 1
1 is inserted. The plate-like fins 11 are provided with a large number of louver-shaped cut-outs 11a, 11b, 11c, 1 on both the front and back sides of the plate-like fins 11 at the intervals between the heat transfer tubes 13.
1d, 11e.

111 is this louver-shaped cut and raised portion 11a.

11b, 11C, 11cl, 118, 11f side parts 11g', 11h', 11i', 11j', 11'
.

111' is formed to be inclined with respect to the airflow B. 14d and 14b indicate dead areas generated on the downstream side of the heat exchanger tubes 13.

According to the fin-tube type heat exchange according to the first embodiment, when the airflow B flows in the direction of the white arrow, the plate-like fins 11
, a large number of louver-shaped cut-outs 11a, 11b are formed on both the front and back surfaces of the plate-like fins 11 at the intervals between the heat exchanger tubes 13.
, 11C211d.

11e and 11f are provided, so this cut-up 1
1a, 11b, 11c, 11d, 11e.

11f provides a boundary layer leading edge effect that prevents the development of a temperature boundary layer. Also, this cut-up 11a.

11b, 110, 11d, 11e, 11f are attached to the side parts 11g', 11h', 11i', 11j', 11'
.

Since the airflow B is formed to be inclined with respect to the inflow direction of the airflow B, the airflow B is formed at the side portion 11g'.

11h', 11 i', 11 j', 11 ni', 111
', a vortex is generated and the heat transfer performance is improved by promoting turbulence, and the airflow B is cut and raised 11a, 11
b.

11C911d, 11e, 11f and side portion 11h'
, 111', 11j', 11', 111', and flows into the downstream side of the heat exchanger tube 13, and the water stop area 14a, 14b on the downstream side of the heat exchanger tube 13 is significantly reduced compared to the conventional one. Therefore, heat transfer performance can be improved.

As described above, according to the first embodiment, it is possible to simultaneously bring out the leading edge effect of the boundary layer, the effect of promoting turbulence, and the effect of reducing the dead area, and the heat transfer coefficient is dramatically increased.

4 to 6 show a second embodiment of the present invention.

In the second embodiment, the louver-shaped cut and raised parts 11a, 11b, 11C, and 11d in the first embodiment are used.

11e and 11f are formed with a portion of the substrate portion 16 of the plate-like fin 11 remaining. According to the fin-tube type heat exchanger according to the second embodiment, when the airflow B flows in the direction of the outlined arrow, a large number of louver-shaped cut-outs 11a are formed on both the front and back surfaces of the plate-like fins 11.

11b, 11c, 11d, 11e, and 11f are formed leaving a portion of the plate-like fin 110 and the base portion 16, so that the flow direction of the airflow B can be changed here, which is better than in the case of the first embodiment. Further boundary leading edge effects can be achieved. Also,
This cut and raise 11a.

11b, 11c, 11d, 11e, and 11f are the side portions 1
1g', 11h', 11i', 11j', 11'.

111' is formed so as to be inclined with respect to the airflow B, the airflow B is caused by the side portions 11q', 11h', 1
1i'.

11]', 11', 111' generates a vortex, and the flow direction is changed by the substrate part 15, and the heat transfer performance is further improved by promoting turbulence than in the first embodiment, and this substrate The presence of the portion 15 also has the effect of reducing the pressure loss of the airflow B.

Furthermore, the airflow B cuts and raises the parts 11a and 11b.

11C911d, 11e, 11f and side portion 11h'.

111', 11j', 11', flows along 111', flows into the downstream side of the heat exchanger tube 13, and the cutoff areas 14a, 14b on the downstream side of the heat exchanger tube 13 are significantly reduced compared to the conventional one. The thermal performance can be improved in the same manner as in the first embodiment. As described above, according to the second embodiment, compared to the first embodiment, it is possible to achieve a further leading edge effect of the boundary layer and a further effect of promoting turbulence, and to bring out the effect of reducing the dead area, thereby dramatically increasing the heat transfer coefficient. This makes it possible to improve the heat exchanger's performance and reduce the pressure loss of the airflow B, thereby significantly improving the performance of the heat exchanger.

Effects of the Invention As described above, the fin-tube heat exchanger of the present invention has a plurality of plate-shaped fins arranged in parallel at regular intervals, through which air flows, and a heat transfer tube inserted at right angles to the plate-shaped fins. A large number of louver-shaped cut-and-raised parts are provided continuously or partly on both the front and back surfaces of the plate-shaped fin in the gap between the heat exchanger tubes of the plate-shaped fin, and the louver By having a configuration in which the side portions of the cut and raised sides are formed to be inclined with respect to the inflow direction of the airflow, the leading edge effect of the boundary layer, the effect of promoting turbulence due to the generation of vortices, and the effect of reducing the cutoff area can be reduced. The three combined effects can promote heat transfer and reduce the pressure loss of the airflow, resulting in the effect of significantly improving the performance of the heat exchanger.

[Brief explanation of drawings]

Fig. 1 is a partial side view showing a fin-tube heat exchanger according to the first embodiment of the present invention, Fig. 2 is a sectional view taken along line D-D in Fig. 1, and Fig. 3 is a cross-sectional view taken along line E-E in Fig. 1. 4 is a partial side view showing a fin-tube heat exchanger according to a second embodiment of the present invention, and FIG. 5 is a sectional view taken along line FF in FIG.
(A) is a sectional view taken along the line G-C in FIG. 4, FIG. 7 is a partial side view showing a conventional fin-tube heat exchanger, and FIG. 8 is a sectional view taken along the line CC in FIG. 7. 11...Plate fins, 11a, 11b, 11c
. 11 d, 11 e, 11 f ・-・-・
Cut up, 11 q'. 11h', 111', 111', 11', 111'・
... Side part, 13 ... Heat exchanger tube, 15 ...
...Base part, B...Airflow. Name of agent: Patent attorney Toshio Nakao and one other person II
-Plate fin 12- Fin collar Fig. 7 2, /f'. le'~ Ia'- 1α'lα'Itr" er7 41'

Claims (2)

[Claims] (1) Consisting of a large number of plate-shaped fins arranged in parallel at regular intervals, through which airflow flows, and heat exchanger tubes inserted at right angles to the plate-shaped fins, the interval between the heat exchanger tubes of the plate-shaped fins A large number of louver-shaped cut-and-raised parts are provided on the front and back of the fin, and the side parts of these louver-shaped cut-and-raised parts are
A fin-tube heat exchanger, characterized in that the fin-tube heat exchanger is formed to be inclined with respect to the inflow direction of the airflow. (2) The fin-tube heat exchanger according to claim 1, wherein the louver-shaped cut and raised portion is formed with a portion of the base portion of the plate-like fin remaining.