JPH0247417Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an outdoor heat exchanger for a heat pump type air conditioner/heater that has an integral auxiliary heat exchanger through which a condensed refrigerant flows during both heating and cooling operations.

Conventional structure and its problems Conventionally, in order to downsize the outdoor heat exchanger of a heat pump type air conditioner/heater, refrigerant turbulence grooves were added to the inner surface of the refrigerant tube that constitutes the heat exchanger (hereinafter referred to as inner grooved tube). ) The capacity was secured by improving the heat transfer coefficient on the refrigerant side.

However, this internally grooved tube has the disadvantage that the pressure drop inside the tube of the refrigerant flow becomes large, and it is customary to divide the refrigerant in a condenser or evaporator to reduce the pressure drop inside the tube. On the other hand, it is known that an outdoor heat exchanger includes an auxiliary heat exchanger that distributes a co-condensed refrigerant during heating and cooling to increase the degree of subcooling during cooling and prevents the outdoor heat exchanger from freezing during heating. However, in this case, since the auxiliary heat exchanger is integrated with the outdoor heat exchanger at the bottom of the outdoor heat exchanger, an inner grooved tube was used like the outdoor heat exchanger. Therefore, the amount of refrigerant circulating decreased due to the generation of flash gas due to the increased pressure drop inside the pipes, resulting in a decrease in heating and cooling capacity and overheating of the compressor.

On the other hand, there is also a method of dividing the refrigerant by increasing the number of refrigerant passages for the auxiliary heat exchanger, but this method has the disadvantage that the auxiliary heat exchanger also has to be made larger, which increases the cost.

Purpose of the invention The present invention has been made in view of the above-mentioned drawbacks, and is intended to reduce the pressure drop in the pipes of the auxiliary heat exchanger, which is formed integrally with the outdoor heat exchanger configured with internally grooved pipes, and to reduce the pressure drop in the pipes. The purpose of the present invention is to provide an inexpensive outdoor heat exchanger that prevents a decrease in capacity due to the occurrence of heat exchangers and secures the effectiveness of the auxiliary heat exchanger.

Structure of the Device In order to achieve this object, the present invention uses smooth tubes as the refrigerant tubes constituting the auxiliary heat exchanger in an outdoor heat exchanger configured with internally grooved tubes to reduce the pressure drop inside the tubes. In this way, a reduction in heating and cooling capacity due to the generation of flash gas is prevented, and an inexpensive outdoor heat exchanger is provided.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner, in which a passage bypasses a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a heating capillary reach tube 4, and a heating capillary tube 4 during cooling. A check valve 5 that forms a An exchanger 6, a capillary reach tube 7 for cooling, a check valve 8 forming a passage that bypasses the capillary reach tube 7 for cooling during heating, and an indoor heat exchanger 9 are connected in an annular manner. During cooling, the refrigerant circulates as shown by the solid line arrow in the figure, and during heating, the refrigerant circulates as shown by the broken line arrow in the figure. FIG. 2 is a side cross-sectional view of the outdoor heat exchanger. The refrigerant tube of the heat exchange section 10, which serves as a condenser for cooling and an evaporator for heating, is composed of an inner grooved tube 11, and the outdoor heat exchanger The refrigerant tube of the auxiliary heat exchanger 6 located at the lower part of the heat exchanger 3 is composed of a smooth tube 12 with a flat inner surface.

In the refrigeration cycle with such a configuration, the auxiliary heat exchanger 6 is made of smooth tubes during both cooling and heating, so the pressure drop inside the tubes is small, and since no flash gas is generated in the auxiliary heat exchanger 6, the cooling air conditioner is not used during cooling. The amount of refrigerant passing through the pillar reach tube 7 and the heating capillary reach tube 5 during heating does not decrease, and a decrease in capacity and overheating of the compressor 1 can be prevented. Furthermore, in order to reduce the pressure drop inside the pipes of the auxiliary heat exchanger 6, there is no need to increase the number of refrigerant passages in the auxiliary heat exchanger 6 to separate the refrigerant, so it is possible to provide an inexpensive outdoor heat exchanger. be.

Effects of the invention As is clear from the above explanation, in the outdoor heat exchanger of the heat pump type air conditioner/heater of the invention, the refrigerant tube constituting the heat exchanger uses a grooved tube on the inside. The refrigerant tube of the auxiliary heat exchanger that is formed and through which the condensate refrigerant flows during both cooling and heating is a smooth tube, so the pressure drop inside the tube in the auxiliary heat exchanger is small, and there is no reduction in cooling or heating capacity due to the generation of flash gas or overheating of the compressor. In addition, since the auxiliary heat exchanger is a smooth tube, an inexpensive outdoor heat exchanger can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention, and FIG. 2 shows a side sectional view of an outdoor heat exchanger. 3...Outdoor heat exchanger, 6...Auxiliary heat exchanger,
11...Tube with inner groove, 12...Smooth tube.

Claims (1)

[Scope of utility model registration request] The plate fins and the refrigerant tube that passes through the fins and has refrigerant turbulence grooves formed on the inner surface constitute an outdoor heat exchanger that serves as a condenser for cooling and an evaporator for heating, and is integrated with this outdoor heat exchanger. This is an outdoor heat exchanger for a heat pump type air conditioner, in which the refrigerant tube of this auxiliary heat exchanger is a smooth tube with a flat inner surface.