JPH07218013A - Heat exchanger for air conditioner - Google Patents

Abstract

PURPOSE:To prevent a temperature rise of a fan motor. CONSTITUTION:An air stream flowing along a fan motor 4 for rotating a fan 3 to be scarcely heat exchanged or after outputting a heat exchanger is made faster at a flowing speed than an air stream flowing at the other place by eliminating fins of a specific part in which the air stream flowing along the motor 4 for rotating the fan 3 after outputting the heat exchanger 1 with many fins mounted on a heat transfer tube, reducing the number of the fins or decreasing a passing resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger with a fan in an outdoor unit of an air conditioner using air as a heat source.

[0002]

2. Description of the Related Art Conventionally, a typical heat exchanger used in an outdoor unit of an air conditioner is shown in, for example, JP-A-63-220093. That is, a finned heat exchanger is constructed by arranging and mounting a plurality of fins having various cut and raised parts in parallel at a constant interval in parallel with a plurality of heat transfer tubes through which a refrigerant passes. Then, the rotation of the fan directly facing this generates an air flow passing between the fins, and the fins are heated or cooled by the outside air to heat or cool the refrigerant in the heat transfer tube. This fan is rotated at a constant speed or a variable speed by a fan motor driven by an AC power source, and the amount of heat exchange is adjusted.

[0003]

In the heat exchanger and fan configured as described above, since the air flow passing through the fan gives heat to the refrigerant or removes heat from the refrigerant,
The temperature is significantly lower or significantly higher than the outside air. If the temperature of the airflow flowing along the fan motor that rotates the fan is high, the fan motor cannot be cooled, and the fan motor is rather heated, causing an increase in temperature. Normally, a fan motor has a number of cooling fins protruding from it, and the airflow flowing along the fins aims to radiate a large amount of heat generated inside the motor to the outside. If the temperature of the external air is high, there is no heat dissipation effect, the temperature of the fan motor rises abnormally, and the reliability of the fan motor decreases, which is not preferable. Further, if the temperature is high, it is also inconvenient in terms of energy efficiency of the motor.

An object of the present invention is to provide a heat exchanger for an air conditioner, which can effectively cool a fan motor by the air flow passing through the fins.

[0005]

In order to achieve such an object, according to the present invention, a plurality of heat transfer tubes are provided with a large number of fins which are orthogonal to each other at regular intervals and which are directly opposed to a fan. In a heat exchanger designed to be heated or cooled by the air passing through them by the rotation of the fan, the air flowing along the fan motor that rotates the fan after exiting the heat exchanger passes through the particular part of the heat exchanger. The heat exchange is made difficult by eliminating the fins, reducing the number or reducing the passage resistance, or the flow velocity of the air flowing along the fan motor after leaving the heat exchanger is It is designed to be faster than the flow velocity.

[0006]

According to the present invention, the airflow flowing along the fan motor that rotates the fan after exiting the heat exchanger rarely exchanges heat with the fins when passing through the heat exchanger. . Therefore, even when the outside air temperature is high especially in summer, the temperature does not rise further. In addition, since the flow velocity of the air flow flowing along the fan motor after exiting the heat exchanger is faster than the flow velocity of the air flow flowing elsewhere, a large amount of air flow will eventually flow and the amount of heat taken directly from the fan motor. Can be a lot. Therefore, the fan motor can be positively cooled by the airflow flowing along the fan motor. For this reason, the temperature rise of the fan motor can be suppressed, and there is a remarkable effect in terms of ensuring reliability. Further, since the motor is operated at a lower temperature, the energy efficiency of the motor is high.

[0007]

The present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view of an air conditioner equipped with the heat exchanger of the present invention. FIG. 1A is the AA of FIG.
A sectional view and FIG. 1B are sectional views taken along the line BB of FIG. Reference numeral 1 is a finned heat exchanger configured by mounting a large number of fins having various cuts and raised orthogonally to a plurality of heat transfer tubes through which a refrigerant is passed and arranged in parallel at regular intervals. The one in the figure consists of a straight part and a bent part. This is vertically attached to the frame 2 of the air conditioner. The fan 3 is placed on the side opposite to the position of the outside air while facing the heat exchanger 1 with fins. The fan 3 is rotated at a constant speed or a variable speed by a fan motor 4 driven by an AC power source. The fan motor 4 is arranged on the side close to the heat exchanger in the heat exchange chamber 7 by connecting the hub 5 of the fan motor to the stay 6 fixed to the air conditioner. This is separated from the machine room 8 that houses the compressor and control circuit.

By rotating the fan 3, an air flow flowing from the outside air through the fins is generated, and the fins are heated or cooled by the outside air to heat or cool the refrigerant flowing in the heat transfer tube. During heating in winter, the temperature of the outside air is low, and since the heat exchanger is used as an evaporator for the refrigerant, the temperature of the air flow becomes lower than that of the outside air when passing through the heat exchanger. Therefore, there is no problem in terms of cooling the fan motor 4 and preventing the temperature rise.
However, during cooling in summer, the temperature of the outside air is high, and since the heat exchanger is used as a condenser of the refrigerant, the temperature of the air flow rises further than the outside air when passing through the heat exchanger. Therefore, it is disadvantageous in terms of cooling the fan motor 4 and preventing the temperature rise. Therefore, in the fan motor 4,
A number of cooling fins 9 are projected, and the airflow flowing along the fins 9 aims to positively radiate a large amount of heat generated inside the motor 4 to the outside.
However, if the temperature of the airflow is high as in this case, not only is there no effect of heat dissipation, but also the situation of heating rather is not preferable.

Therefore, in the heat exchanger 1 of the present invention, heat exchange is made difficult by reducing the contact of the air flow B'flowing along the fan motor 4 with the fins when passing through the heat exchanger. Alternatively, the air flow B'flowing along the fan motor is higher than the flow velocity of the air flow A'flowing elsewhere.

2 to 4 show a heat exchanger 1 for this purpose.
Shows the configuration of. In particular, the portion where the outside air B in FIG. 1 becomes the air flow B ′ that cools the fan motor 4 is shown enlarged. Reference numeral 10 is a transmission pipe through which the refrigerant passes, and 11 is a plurality of fins attached orthogonally to the transmission pipe, so that the cut and raised parts are not shown.

In FIG. 2, fins at specific portions are continuously removed to create a finless dance.

In FIG. 3, the fins of a specific part are removed by thinning them out.

In FIG. 4, the fins in a specific portion are deformed and displaced to aim for the same effect as in FIG.

In addition to this, fins with little cut and raised may be arranged at this portion. Further, in the case where a plurality of rows of fins are arranged for the air flow, some of the rows may be removed.

By doing so, the outside air B becomes
Since the direct contact with the fins 11 is reduced, the temperature of the outside air is less likely to rise due to heat exchange. Therefore, the fan motor 4 can be efficiently cooled by the air flow B ′ passing through the fins. Further, by doing so, the fluid resistance when passing through the fins 11 is small, so the pressure loss is small. Therefore,
The flow velocity of the air flow B'passing through the fin becomes faster than the flow velocity of the other parts, and the air volume increases. Therefore, the fan motor 4 can be cooled more effectively.

FIG. 5 shows an air conditioner provided with an air guide 12 in order to more positively utilize this air flow B'for cooling the fan motor. In this example, the plate material is arranged in a cylindrical shape from the outlet of the air flow of the heat exchanger 1 toward the fan motor 4 and attached to the stay.

As described above, the airflow B'which avoids the temperature rise from the outside air B is guided by the air guide 12 to the fan motor 4
It is guided to the place smoothly. Therefore, the fan motor 4 can be cooled more effectively without being mixed with the high temperature air flow A ′ in other parts and without causing a decrease in flow velocity. In particular, since the rotation peripheral speed is slow in the central part of the fan, it is inevitable that the flow velocity will be lower than that in the peripheral portion. Therefore, in order to cool the fan motor, a device for increasing the flow velocity in this way is devised. Is preferred. Further, the stay 6 is also preferably designed to have a small area with respect to the flow or to be streamlined so as not to obstruct the air flow for cooling the fan motor 4.

[0019]

As described above, according to the present invention, not only the disadvantageous situation that the fan motor is heated by the air flow passing through the fin in the related art can be avoided, but also the outside air having a low temperature is used as it is. Can be actively cooled by. For this reason, the temperature rise of the fan motor can be prevented, and a remarkable effect in terms of reliability can be expected. In particular, a heat transfer tube having a small diameter which has been widely used in recent years is used, and it is suitable for a heat exchanger having a narrow fin interval.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an air conditioner including a heat exchanger of the present invention.

FIG. 2 is a partially enlarged view of the heat exchanger of the present invention.

FIG. 3 is a partially enlarged view of the heat exchanger of the present invention.

FIG. 4 is a partially enlarged view of the heat exchanger of the present invention.

FIG. 5 is an explanatory diagram of an air conditioner including another embodiment of the present invention.

[Explanation of symbols]

1 ... Heat exchanger, 2 ... Frame, 3 ... Fan, 4 ... Fan motor, 5 ... Hub, 6 ... Stay, 7 ... Heat exchange chamber, 8 ... Machine room, 9 ... Cooling fin, 10 ... Heat transfer tube, 11 … Fins, 1
2 ... Air guide.

Claims (1)

[Claims] 1. A heat exchange system in which a plurality of fins are mounted orthogonally to a plurality of heat transfer tubes at regular intervals and are heated or cooled by air passing therethrough by rotation of a fan facing the heat transfer tubes. In a heat exchanger, air flowing along a fan motor that rotates the fan after exiting the heat exchanger eliminates or reduces the number of fins in certain parts passing through the heat exchanger or reduces passage resistance. By this, heat exchange is made difficult, or the flow velocity of the air flowing along the fan motor after exiting the heat exchanger is made faster than the flow velocity of the air flowing elsewhere. Heat exchanger for air conditioner.