Abstract: A heat exchanger-use fin includes a fin body, collars and erect portions. The fin body has a plurality of holes. The collars surround the holes. The collars are disposed between two straight lines on a surface of the fin body. Outer peripheries of the collars contact the straight lines. The erect portions are positioned outside the two straight lines. Distal ends of the erect portions are in higher positions than distal ends of the collars relative to the surface of the fin body. A guide used with the fin includes first and second alternately arranged grooves. The second grooves are deeper than the first grooves. A method of using the guide includes slidably fitting the collars into one of the first grooves, and fitting the erect portions into the second groove adjacent to the first groove having the collars fitted therein.

Abstract: An indoor unit for a multi-directional air supply air conditioner capable of performing at least a heating operation includes: an indoor fan (39) for sucking air in an axial direction thereof and radially blowing out the air; and a heat exchange part (38), connected in a refrigerant circuit (80) and disposed to surround the indoor fan (39), for exchanging heat between the air blown out of the indoor fan (39) and refrigerant in the refrigerant circuit (80). The heat exchange part (38) includes a plurality of heat exchangers (48) separated from each other along the direction of the perimeter thereof and connected in parallel with each other in the refrigerant circuit (80).

Abstract: A refrigerant flow divider is made up of an inlet pipe 12 through which refrigerant Xin flows in, a main body 11 of which the inside is a cavity, and a plurality of branching pipes 13 through which refrigerant Xout flows out. When the length of the above described main body 11 of the flow divider is L mm and the inner diameter of the above described main body 11 of the flow divider is D2 mm, the relationship 2 ?L/D2?8 holds, and thus, a flow divider can be gained, where discrepancy (variation) in the flow rate ratio in the respective paths for the flow discharged from the outlet of the flow divider and entering the heat exchanger is small and pressure loss is small when there is a change of approximately ±10° in the installation angle, a change in the dryness of the refrigerant at the inlet (0.2 to 0.4) or a change in the flow rate of the refrigerant (50% to 100%).

Abstract: The present invention relates to a hot water corrugated heat transfer tube that exchanges heat between its interior and exterior. A plurality of projections, each whose height (H1) is in the range of 0.5 mm-1.5 mm, is provided in at least one part of the inner surface of a portion positioned in a section of a corrugated heat transfer tube, where the Reynolds number (Re) of the fluid flowing in the interior of the tube is less than 7,000. The height H1 of the projections is in the range of 0.05-0.15 times the inner diameter D or the height H1 of the projections is in the range of 1-3 times the depth (Hm) of the corrugated grooves. As a result, with a simple structure, the heat transfer performance in the low Reynolds number zone is improved, and the pressure loss inside the tube is small.

Abstract: The present invention relates to a hot water heat transfer pipe that exchanges heat between its interior and exterior. A plurality of projections, each having a height in the range of 0.8-2.0 mm or 0.1-0.25 times the inner diameter, is provided in at least one part of an inner surface of a portion of the heat transfer pipe positioned in a section where the Reynolds number of the fluid flowing in the interior is less than 7,000 to improve the heat transfer performance in the low Reynolds number zone, and minimize pressure loss inside the pipe.

Abstract: Surface portions A with a low heat capacity and surface portions B to which frost or ice is poorly bound or attached are discretely distributed on the heat exchange surface. The surface portions A and the surface portions B have features by which, when heating the heat exchanger to which frost or ice is attached, frost or ice in contact with the surface portions A melts earlier than frost or ice in contact with the surface portions B, and at least a part of frost or ice attached to the surface portions B is made partially continuous with at least a part of frost or ice attached to the surface portions A and is thereby released from the surface portions B by its own weight. The heat exchanger having such a heat exchange surface is used as an evaporator of a refrigeration apparatus.