JPS6080092A - Heat exchanger equipped with fin - Google Patents

Abstract

PURPOSE:To permit to exchange heat with a refrigerant (heat medium) which generates a temperature change upon exchanging heat with a good temperature efficiency by a method wherein plural sheets of fins are provided with a plurality of holes respectively and the plurality of holes are utilized for the paths of airflows. CONSTITUTION:A fan 15 is enclosed by copper pipes 14 and is arranged between the plural sheets of aluminum fins 13 which are divided into fore and aft parts. The aluminum fins 13 are bored with the plurality of holes 12 while the holes constitutes the paths of airflows induced by the fan 15. The aluminum fins 13 and the copper pipes 14 are contacted thermally by the method of expanding the pipes or the like. The refrigerant, passing through the insides of the copper pipes 14, and air, flowed by the fan 15, exchange the heat thereof with each other. The plurality of aluminum fins have an effect to eliminate noise generated by the fan 15 and, as a result, heat exchange may be effected with low noise and good temperature efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a finned heat exchanger used for heat radiation (heat absorption) for air conditioning or refrigeration.

Conventional configurations and their problems Most finned heat exchangers are composed of a two-base group of copper tubes through which refrigerant flows, and multiple aluminum fins attached perpendicularly or at an angle close to that. , has the function of thermally contacting the air flowing between the aluminum fins and the refrigerant flowing within the copper tubes, thereby exchanging heat. 1st
The figure shows a conventional heat exchanger with fins, where 1 shows aluminum fins and 2 shows steel pipes. Air is made to flow in the direction of the arrow using a means such as a fan. The flow direction of the air is perpendicular to the copper tube 2 and parallel to the heat transfer surface of the aluminum fin 2. Therefore, air and refrigerant are in cross flow. When the refrigerant exchanges heat with the air at a constant temperature, the temperature efficiency is the same as when the air and refrigerant flow in countercurrent flow, but when a refrigerant whose temperature changes during heat exchange is used, Cross flow, such as in conventional finned heat exchangers, reduces its thermal efficiency.

Also, when using such a finned heat exchanger as an evaporator for heat pump heating in winter, the tip of each fin should be t''
! , when the temperature is approximately the same, frost will form on the high mass transfer rate portion at the fin tip, and a frost lump will form near the fin tip in a relatively short time. As a result, the air passages at the leading edges of the fins become more constricted than usual, increasing ventilation resistance and reducing the performance of the finned heat exchanger, as well as reducing the heating capacity and efficiency of the heat pump. .

In a heat exchanger with fins as shown in Fig. 1, only the configuration in which the refrigerant and the air are perpendicular to each other could be adopted, but in the configuration according to the present invention, the refrigerant and the air are opposed to each other, and the temperature changes while the refrigerant exchanges heat with the air. In this case, the temperature efficiency of the counter-flow type is higher than that of the cross-flow type.

In addition, conventionally, heat exchangers with fins are used in heat pump heaters,
However, when used as an evaporator in a water heater, etc., when the outside temperature drops, frost often forms on the fin surface, which causes a decrease in the performance of the finned heat exchanger, causing problems with heating and hot water supply. This led to a decline in capacity and performance. This deterioration in the performance of finned heat exchangers due to frost formation is due to the fact that in conventional finned heat exchangers, the refrigerant and air are in cross-flow type, and the leading edge of the fin, which has the highest mass transfer rate, is used to exchange heat with the air. This occurs because it is in the inlet of the blood vessel. In other words, MiBHGO in front of each fin
-80092 (2) The edges are boxed relatively evenly and the air passages are blocked, which prevents air from flowing into the finned heat exchanger.

The heat transfer rate between this waste air and the refrigerant is significantly lowered, and the heat exchange performance is lowered.

Purpose of the Invention The present invention is capable of efficiently exchanging heat even with a refrigerant (heat medium) that causes temperature changes during heat exchange, and at the same time, when used as an evaporator for heat pump heating or hot water supply, it is possible to prevent frost formation in winter. The purpose of the present invention is to provide a counterflow type, low-noise finned heat exchanger with a small reduction in efficiency.

Structure of the Invention The finned heat exchanger according to the present invention is composed of a plurality of fins placed facing the airflow and a plurality of heat transfer tubes attached perpendicularly to these fins. It has a configuration in which the plurality of holes are made into airflow passages.

The fins of the heat exchanger with fins having the above-mentioned configuration are divided into two parts each, and the fins are installed in front and behind the fan that generates the airflow flowing inside the fins. Arrange the heat tubes so that they surround the fan.

Description of examples Embodiments according to the present invention are shown in FIGS. 2, 3, and 4.

The embodiment shown in FIG. 2 allows for complete counterflow of air and refrigerant. Air flowing in the direction of the arrow passes through the holes 4 and is guided to the rear of the heat exchanger. At this time, the refrigerant flows inside the steel pipe 6 facing the air, and the aluminum fin 5
and exchange heat on the surface of the copper tube e.

When the present invention is implemented, the flow of the refrigerant is opposed to the air, so that the high temperature part of the refrigerant or the superheated region can reach the air flowing into the heat exchanger where the water vapor concentration inside the air is highest. It is possible. Furthermore, although the amount of frost is greatest near the heat exchanger tubes, in the present invention the air passages are provided relatively far from the heat exchanger tubes, so the air passages are always secured and the amount of frost is reduced from the front to the rear of the heat exchanger. The air flow is not obstructed in a short period of time due to a small amount of frost, unlike the conventional case where frost buildup is unevenly formed on the front edge of the thermal six-page exchanger. Of course, when operating under frost conditions for a long time, the performance of the finned heat exchanger according to the embodiment of the present invention deteriorates, but the rate of performance deterioration is significantly lower than that of the conventional heat exchanger.

FIG. 3 shows another embodiment according to the invention. The difference from the embodiment shown in FIG. 2 is that the refrigerant branching header 3 is not provided. The U-bend 7 changes the flow direction of the refrigerant flowing inside the copper tube 9. Air flowing in the direction of the arrow passes through the plurality of holes 8 and flows between the fins 10. At this time, air and refrigerant exchange their respective heats through steel pipes and fins.

In the embodiment shown in Fig. 3, the air and refrigerant do not flow completely in opposite directions, but alternately flow in parallel and countercurrently, but the effect is not that different from that in the embodiment shown in Fig. 2. There isn't.

FIG. 4 shows yet another embodiment of the invention.

The fan 16 is surrounded by a copper tube 14 and installed between a plurality of aluminum fins 13 divided into front and rear parts.

7. The aluminum fin 13 has a plurality of holes 12 opened therein, and the holes 12 constitute a passage for air flow induced by the fan 15. The aluminum fins 13 and the copper tube 14 are brought into thermal contact by a method such as tube expansion. The refrigerant passing through the copper tube 14 and the air flowing by the fan 15 exchange heat with each other. In this embodiment, a plurality of aluminum fins installed before and after the fan 16 have the effect of muffling the noise generated from the fan 15, and as a result, a counterflow type heat exchanger with low noise and high temperature efficiency is created. It is something that can be realized.

The present invention has realized a counterflow type heat exchanger with a heat exchanger, which has been difficult to realize in the past. It is possible to construct a heat exchanger that does not deteriorate in performance for a long time even under frost conditions, and the capacity and performance during heat pump heating and hot water supply can be improved.

Furthermore, in the present invention, the air that has passed through the holes in the fin becomes a jet and hits the next fin.
0092 (3) Because of the impact, the heat transfer coefficient between the air and the fins is significantly improved compared to the increase in pressure drop.

The present invention is based on the scope of the second claim.As shown in the embodiments, the present invention also has the effect that the heat exchanger can be operated with very low noise.

As described above, the present invention brings about remarkable effects such as improvement in the temperature efficiency of the finned heat exchanger, reduction in capacity and performance deterioration during frost formation, low noise, and high heat transfer coefficient. This effect also makes it possible to improve the performance and capacity of the heat pump.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a finned heat exchanger according to an embodiment of the conventional technology, FIG. 2 is a schematic perspective view of a finned heat exchanger according to an embodiment of the present invention, and FIGS. FIG. 3 is a schematic configuration diagram of a different embodiment of the invention. 5+ 10.13...River Fin, 4,8.12...
...hole. Name of agent: Patent attorney Toshio Nakao and one other physician, - Ajiho

Claims (1)

[Claims] 1. Consisting of a plurality of fins placed facing the airflow and a plurality of heat transfer tubes attached perpendicularly to these fins, a plurality of holes are formed in each of the plurality of fins, and a plurality of holes are formed in each of the plurality of fins. A heat exchanger with fins that uses multiple holes as airflow passages. 2. A patent claim in which a plurality of fins of the finned heat exchanger are installed in front and behind the fan for generating the airflow, and a plurality of heat transfer tubes attached to the fins are arranged so as to surround the fan. The finned heat exchanger according to item 1.