JPH10197183A - Finned heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of heat exchanging amount and restrain frosting at the upstream of air stream to elongate the period of time of heating operation by a method wherein continuous draining groove is provided in the direction of gravity between mutual rows of heat transfer tubes on a fin. SOLUTION: Heat exchange is effected between air flow, which flows between fins 4, and refrigerant, which flows through the inside of a heat transfer tube 2, through the fin 4 and the heat transfer tube 2. In this case, when the evaporating temperature of the refrigerant is lowered, moisture in air is condensed on the surface of the fin 4a at the upstream side of the air flow. The condensate is conducted by the air flow to flow along the fin 4a toward the downstream of the air flow and flows into a draining groove 5, continued in the direction of gravity between mutual rows of the heat transfer tubes 2 on the fin 4, then, is discharged into the direction of gravity. Accordingly, the inflow of the condensate, condensed on the fin 4a at the upstream of the air flow and precluding the heat exchange between the air flow and the fin 4, into a fin 4b at the downstream side of the air flow is prevented whereby the deterioration of heat exchanging amount between the fin 4b at the downstream side of the air flow and the air flow can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finned heat exchanger for transferring heat between a refrigerant and a fluid such as air in an air conditioner, refrigeration equipment, automobile equipment, and the like.

[0002]

2. Description of the Related Art In recent years, heat exchangers with fins have been required to be compact in terms of equipment design, and high efficiency has been achieved by providing slits and louvers on the fin surface.

A conventional finned heat exchanger is disclosed in
No. 252494.

Hereinafter, the conventional finned heat exchanger will be described with reference to the drawings. FIG. 7 is a perspective view of a conventional finned heat exchanger. In FIG. 7, reference numeral 1 denotes fins arranged in parallel at regular intervals, and 2 denotes a heat transfer tube which penetrates the fin 1 and through which a fluid flows. A refrigerant circuit is formed by connecting the heat transfer tubes 2 to each other. FIG. 8 is a cross-sectional view of a conventional finned heat exchanger, and FIG.
It is -A sectional drawing. 8 and 9, reference numeral 3 denotes a fin 1
It is a slit-like cut-and-raised provided on the upper side.

[0005] The operation of the finned heat exchanger configured as described above will be described below.

In this finned heat exchanger, the airflow flowing between the fins 1 and the refrigerant flowing in the heat transfer tubes 2 are
Heat exchange is performed via the fins 1 and the heat transfer tubes 2. At this time, the fin 1 is provided with a slit-shaped cut-and-raised portion 3, and the cut-and-raised portion 3 updates a boundary layer of an airflow flowing between the fins 1 to promote heat exchange between the airflow and the fin 1. As a result, heat exchange between the airflow and the refrigerant flowing in the heat transfer tube is promoted.

[0007]

However, in the above-described conventional configuration, when functioning as an evaporator during a heating operation, when the evaporating temperature of the refrigerant decreases, the air in the air condensed on the surface of the fins 1a upstream of the airflow flows. Moisture travels along the fins 1 by the airflow, gradually flows downstream of the airflow, and flows into the fins 1b downstream of the airflow. This condensed water hinders heat exchange between the airflow and the fins 1b downstream of the airflow, and has the disadvantage that the heat exchange amount of the finned heat exchanger is reduced.

SUMMARY OF THE INVENTION The present invention solves the conventional problem. When the evaporator functions as an evaporator during a heating operation, when the evaporating temperature of the refrigerant is reduced, the amount of heat exchange downstream of the airflow is prevented from being reduced. The purpose is to maintain the heat exchange amount of the attached heat exchanger.

Further, in the above-described conventional configuration, when functioning as an evaporator during the heating operation, when the evaporation temperature of the refrigerant decreases, the water condensed on the surface of the fin 1a upstream of the air flow is
In the upstream of the airflow, it hinders heat exchange between the airflow and the fins 1,
There is a disadvantage that the heat exchange amount of the finned heat exchanger is reduced.

Another object of the present invention is to maintain the heat exchange amount of the finned heat exchanger by preventing a decrease in the amount of heat exchange downstream of the airflow and preventing a decrease in the amount of heat exchange upstream of the airflow. That is.

Furthermore, in the above-described conventional configuration, when the evaporator functions as an evaporator during the heating operation, the evaporation temperature of the refrigerant decreases, and when the evaporation temperature of the refrigerant becomes 0 ° C. or less, the refrigerant condenses on the surface of the fin 1 upstream of the airflow. The generated moisture causes a large amount of frost immediately after the start of operation at the leading edge of the cut-and-raised portion 3 that renews the boundary layer of the airflow having a large heat exchange amount. In order to cause clogging, ventilation resistance increases, and although heat exchange can be performed downstream of the airflow, heating operation is stopped and defrosting operation is started, so frequent defrosting operations have to be performed. There was a disadvantage.

Still another object of the present invention is to reduce the amount of heat exchange of the finned heat exchanger by preventing the heat exchange amount of the finned heat exchanger from lowering and suppressing frost formation upstream of the airflow. It is intended to extend the heating operation time without causing the heating operation.

[0013]

In order to achieve this object, the present invention provides a gravitationally continuous drain groove between rows of heat transfer tubes of fins.

Thus, when the evaporator functions as an evaporator during the heating operation, when the evaporating temperature of the refrigerant decreases, the moisture in the air condensed on the surfaces of the fins upstream of the airflow is prevented from flowing into the downstream of the airflow. In addition, it is possible to prevent a decrease in the amount of heat exchange of the fins downstream of the airflow and maintain the amount of heat exchange of the finned exchanger.

Further, the present invention is characterized in that a drain groove continuous in the weight direction is provided between the rows of heat transfer tubes of the fins, and the fin surface from the leading edge of the fin upstream of the airflow to the drain groove is subjected to a water-repellent surface treatment. It is.

When the evaporator functions as an evaporator during a heating operation, when the evaporating temperature of the refrigerant decreases, the moisture in the air condensed on the surface of the fin upstream of the airflow flows into the downstream of the airflow. Prevented by inter-row drains.
In addition, since the fin surface from the leading edge of the fin upstream of the airflow to the drainage groove is subjected to a water-repellent surface treatment, this condensed water becomes water droplets and is easily flown into the airflow, so that the condensed water is condensed on the surface of the fin upstream of the airflow. In large quantities and quickly drained from drains. Thus, it is possible to prevent a decrease in the amount of heat exchange both upstream and downstream of the airflow, and to maintain the amount of heat exchange of the finned heat exchanger.

Further, the present invention provides a drain groove which is continuous in the weight direction between the rows of heat transfer tubes of the fins, and performs a water-repellent surface treatment on the fin surface from the leading edge of the fin upstream of the airflow to the drain groove. The part from the leading edge to the drain is flat.

When the evaporator functions as an evaporator during the heating operation, when the evaporating temperature of the refrigerant decreases, the moisture in the air condensed on the surface of the fin upstream of the airflow flows into the downstream of the airflow. Prevented by inter-row drains.
In addition, since the fin surface from the leading edge of the fin upstream of the airflow to the drainage groove has been subjected to a water-repellent surface treatment, the condensed water becomes water droplets and is easily flown into the airflow. It is drained in large quantities and quickly. Thus, it is possible to prevent a decrease in the amount of heat exchange both upstream and downstream of the airflow, and to maintain the amount of heat exchange of the finned heat exchanger. Further, when the evaporating temperature of the refrigerant decreases and the evaporating temperature of the refrigerant becomes 0 ° C. or less, clogging of the gap between the cut-and-raised portion and the fin of the base can be eliminated, and the heating operation time can be extended.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is arranged in parallel at regular intervals, and fins in which gas flows between the fins and a plurality of fins penetrating the fins and arranged in the gas flow direction. A heat exchanger with fins comprising a heat transfer tube and a drainage groove continuous in the weight direction between rows of heat transfer tubes of fins, and a drainage groove continuous in the direction of gravity between the rows of heat transfer tubes of fins. Prevents the water in the air condensed on the surface of the fins upstream of the airflow from flowing into the downstream of the airflow, prevents the heat exchange amount of the fins downstream of the airflow from decreasing, and reduces the heat exchange amount of the finned heat exchanger. Can be maintained.

According to a second aspect of the present invention, there is provided the finned heat exchanger according to the first aspect, wherein the fin surface from the leading edge of the fin upstream of the airflow to the drain is subjected to a water-repellent surface treatment. By providing a drainage groove that is continuous in the direction of gravity between the rows of heat transfer tubes of the fins, and applying a water-repellent surface treatment to the fin surface from the leading edge of the fin upstream of the airflow to the drainage groove, the surface of the fins upstream of the airflow While preventing the water in the condensed air from flowing downstream of the airflow, this condensed water becomes water droplets,
By facilitating the flow in the air flow, the condensed water is quickly drained by the drainage grooves on the surface of the fins upstream of the air flow, preventing a decrease in the amount of heat exchange both upstream and downstream of the air flow,
This has the effect that the heat exchange amount of the finned heat exchanger can be maintained.

According to a third aspect of the present invention, there is provided the heat exchanger with fins according to the second aspect, wherein a portion from the leading edge of the fin upstream of the airflow to the drainage groove is flattened. Provide drainage grooves that are continuous in the direction of gravity between each other, apply a water-repellent surface treatment to the fin surface from the fin leading edge to the drainage groove upstream of the airflow, and flatten the part from the fin leading edge to the drainage groove upstream of the airflow. By doing so, clogging of the gap between the cut-and-raised and the fins of the base is eliminated, and the heating operation time can be extended. In addition, while preventing the moisture in the air condensed on the surface of the fin upstream of the airflow from flowing into the downstream of the airflow, the moisture in the air condensed on the surface of the fin upstream of the airflow becomes a water droplet and is easily flowed into the airflow. Therefore, on the surface of the fins upstream of the airflow, the condensed water is quickly drained, preventing a decrease in the amount of heat exchange both upstream and downstream of the airflow, and maintaining the heat exchange amount of the finned heat exchanger. Have.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a finned heat exchanger according to the present invention will be described below with reference to the drawings. Note that the same components as those in the related art are denoted by the same reference numerals, and detailed description is omitted.

(Embodiment 1) FIG. 1 is a sectional view of a finned heat exchanger according to Embodiment 1 of the present invention, and FIG.
It is B sectional drawing.

In the figure, reference numeral 2 denotes a heat transfer tube, which is the same as a conventional structure. Reference numeral 4 denotes fins arranged in parallel at regular intervals, and reference numeral 5 denotes a drainage groove which is continuously provided between the rows of the heat transfer tubes 2 of the fins 4 in the force direction.

The operation of the finned heat exchanger configured as described above when it functions as an evaporator during a heating operation will be described below.

In this heat exchanger with fins, the airflow flowing between the fins 4 and the refrigerant flowing in the heat transfer tubes 2
Heat exchange is performed via the fins 4 and the heat transfer tubes 2. At this time, when the evaporation temperature of the refrigerant decreases, moisture in the air condenses on the surface of the fin 4a upstream of the airflow.

The condensed water is caused to flow downstream of the air flow along the fins 4a by the air flow, and flows into the drain grooves 5 continuous in the direction of the force of the rows of the heat transfer tubes 2 of the fins 4. Drain 5
Is discharged along the drain 5 in the direction of gravity.

For this reason, the condensed water condensed by the fins 4a upstream of the airflow, which inhibits the heat exchange between the airflow and the fins 4, is prevented from flowing into the fins 4b downstream of the airflow. It is possible to prevent a decrease in the exchange amount and maintain the heat exchange amount of the finned heat exchanger.

As described above, in the heat exchanger with fins of the present embodiment, by providing the drainage grooves 5 continuous in the direction of gravity between the rows of the heat transfer tubes 2 of the fins 4, the fins 4a on the upstream of the air flow are provided.
It is possible to prevent the moisture in the air condensed on the surface from flowing into the downstream of the air flow, prevent the heat exchange amount of the fins 4b downstream of the air flow from decreasing, and maintain the heat exchange amount of the finned heat exchanger.

(Embodiment 2) FIG. 3 is a sectional view of a finned heat exchanger according to Embodiment 2 of the present invention, and FIG.
It is C sectional drawing.

In FIG. 1, reference numeral 2 denotes a heat transfer tube, which is the same as a conventional structure. Numeral 6 denotes fins arranged in parallel at regular intervals, and numeral 7 denotes a drainage groove continuous between rows of the heat transfer tubes 2 of the fins 6 in the direction of gravity. Reference numeral 8 denotes a water-repellent surface treatment applied to the surface of the fin 6a upstream of the airflow between the leading edge of the fin 6 and the drain groove 7.

The operation of the finned heat exchanger configured as described above when it functions as an evaporator during a heating operation will be described below.

In this heat exchanger with fins, the airflow flowing between the fins 6 and the refrigerant flowing in the heat transfer tubes 2
Heat exchange is performed via the fins 6 and the heat transfer tubes 2. At this time, when the evaporation temperature of the refrigerant decreases, moisture in the air condenses on the surface of the fin 6a upstream of the airflow. Since the water repellent surface treatment is applied to the fins 6a on the upstream side of the airflow, the condensed water becomes water droplets and is easily flowed into the airflow. Therefore, a large amount of the condensed water is guided to the drain 7 by the airflow, and is quickly discharged by the drain 7 in the direction of gravity.

Thus, a large amount of condensed water, which inhibits the heat exchange between the surface of the fin 6a upstream of the air flow and the air flow, is quickly discharged, and the flow of the condensed water into the fin 6b downstream of the air flow is prevented. Both the upstream fin 6a and the fin 6b downstream of the airflow can prevent a decrease in the amount of heat exchange with the airflow, and can maintain the heat exchange amount of the finned heat exchanger.

As described above, in the heat exchanger with fins of the present embodiment, the drain grooves 7 continuous in the direction of gravity are provided between the rows of the heat transfer tubes 2 of the fins 6, and the fins 6a are located upstream of the airflow from the front edge. By performing the water-repellent surface treatment 8 on the surface of the fin 6a up to the drain groove 7, the water in the air condensed on the surface of the fin 6a upstream of the air flow is prevented from flowing into the downstream of the air flow, and the condensed water is prevented from flowing. A large amount of condensed water is rapidly and rapidly drained by the drain groove 7 on the surface of the fin 6a upstream of the air flow by making it easy to be formed into a water droplet and flown to the air flow, so that the fin 6a upstream of the air flow and the fin 6b downstream of the air flow are condensed. In both cases, a decrease in the amount of heat exchange can be prevented, and the amount of heat exchange of the finned heat exchanger can be maintained.

(Embodiment 3) FIG. 5 is a sectional view of a finned heat exchanger according to Embodiment 3 of the present invention, and FIG.
It is D sectional drawing.

In the figure, reference numeral 2 denotes a heat transfer tube, which is the same as a conventional structure. Reference numeral 9 denotes fins arranged in parallel at regular intervals, and reference numeral 10 denotes a drainage groove continuous between rows of the heat transfer tubes 2 of the fins 9 in the direction of gravity. Numeral 11 denotes a water-repellent surface treatment applied to the surface of the fin 9a upstream of the airflow between the leading edge of the fin 9 and the drain groove 10. Further, the fin 9a upstream of the airflow is flat without being cut or raised.

The operation of the finned heat exchanger configured as described above when it functions as an evaporator during a heating operation will be described below.

In this heat exchanger with fins, the airflow flowing between the fins 9 and the refrigerant flowing in the heat transfer tubes 2
Heat exchange is performed via the fins 9 and the heat transfer tubes 2. At this time, when the evaporation temperature of the refrigerant decreases, moisture in the air condenses on the surface of the fin 9a upstream of the airflow.

Since the water repellent surface treatment 11 is applied to the surface of the fin 9a on the upstream side of the airflow, this condensed water becomes water droplets, and the fin 9a on the upstream side of the airflow is flat without any slit-shaped cut-and-raised portions. It is very easy to be swept away by the air current. For this reason, a large amount of the condensed water is guided to the drain 10 by the air current and quickly, and is discharged in the direction of gravity by the drain 10.

Thus, a large amount of condensed water that inhibits the heat exchange between the fin 9a and the air flow is quickly and quickly discharged from the surface of the fin 9a upstream of the air flow, and the flow of the condensed water into the fin 9b downstream of the air flow is prevented. Accordingly, it is possible to prevent a decrease in the amount of heat exchange between the fins 9 and the airflow, and to maintain the amount of heat exchange of the finned heat exchanger.

When the evaporating temperature of the refrigerant further decreases and the evaporating temperature of the refrigerant becomes 0 ° C. or less, the fins 9a on the upstream of the airflow flow.
Since there is no slit-like cut-and-raised portion, the gap between the cut-and-raised portion and the base fin 9 does not become clogged as in the conventional example, the increase in ventilation resistance can be suppressed, and the heating operation time can be reduced. Can be extended.

As described above, in the heat exchanger with fins of the present embodiment, the drain grooves 10 continuous in the direction of gravity are provided between the rows of the heat transfer tubes 2 of the fins 9, and the drains are discharged from the front edge of the fin 9a upstream of the air flow. Water-repellent surface treatment 1 on fin 9a surface up to groove 10
1 and drain grooves 1 from the leading edge of the fin 9a upstream of the airflow.
By flattening the portion up to 0, clogging of the gap between the cut-and-raised portion and the fin 9 of the base can be eliminated, and the heating operation time can be extended.

In addition, the moisture in the air condensed on the surface of the fin 9a upstream of the air flow is prevented from flowing into the fin 9b downstream of the air flow, and the moisture in the air condensed on the surface of the fin 9a upstream of the air flow is removed by water droplets. Therefore, the drainage groove 1 is formed on the surface of the fin 9a upstream of the airflow.
A large amount of water condensed by 0 is quickly and quickly drained,
Both the fin 9a upstream of the airflow and the fin 9b downstream of the airflow can prevent a decrease in the amount of heat exchange, and can maintain the amount of heat exchange of the finned heat exchanger.

[0045]

As described above, according to the present invention, fins are arranged in parallel at regular intervals and gas flows between them.
The fins penetrate through the fins and are arranged in a plurality of rows in the airflow direction.The drainage grooves are continuous in the direction of gravity between the rows of the fins. It is possible to prevent the heat exchanger from lowering and maintain the heat exchange amount of the finned heat exchanger.

Further, since the fin surface from the leading edge of the fin upstream of the airflow to the drainage groove is subjected to a water-repellent surface treatment, the amount of heat exchange is prevented from decreasing both upstream and downstream of the airflow, and the heat exchange amount of the finned heat exchanger is reduced. Can be maintained.

Further, since the portion from the leading edge of the fin upstream of the airflow to the drainage groove is made flat, it is possible to prevent a decrease in the amount of heat exchange downstream of the airflow and to suppress frost formation upstream of the airflow, thereby providing a fin. The heating operation time can be extended without reducing the heat exchange amount of the heat exchanger.

[Brief description of the drawings]

FIG. 1 is a sectional view of a finned heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG. 1;

FIG. 3 is a sectional view of Embodiment 2 of the finned heat exchanger according to the present invention.

FIG. 4 is a sectional view taken along the line CC of FIG. 3;

FIG. 5 is a sectional view of a finned heat exchanger according to a third embodiment of the present invention.

FIG. 6 is a sectional view taken along line DD of FIG. 5;

FIG. 7 is a perspective view of a conventional finned heat exchanger.

FIG. 8 is a sectional view of a conventional finned heat exchanger.

9 is a sectional view taken along line AA of FIG. 8;

[Explanation of symbols]

 2 Heat transfer tube 4, 4a, 4b fin 5 Drain groove 6, 6a, 6b fin 7 Drain groove 8 Water repellent surface treatment 9, 9a, 9b Fin 10 Drain groove 11 Water repellent surface treatment

Claims (3)

[Claims] 1. A fin which is arranged in parallel at regular intervals and through which a gas flows, and a plurality of heat transfer tubes penetrating through the fins and arranged in a plurality of rows in a gas flow direction, wherein the heat transfer tubes of the fins are provided. Heat exchanger with fins provided with drainage grooves continuous in the direction of gravity between the rows of. 2. The finned heat exchanger according to claim 1, wherein the fin surface from the leading edge of the fin upstream of the airflow to the drainage groove is subjected to a water-repellent surface treatment. 3. The heat exchanger with fins according to claim 2, wherein a portion from the leading edge of the fin upstream of the airflow to the drain groove is flattened.