Matsushita Electric Industrial Co., Ltd.

Osamu Aoyagi

Shoichi Yokoyama

Hitoshi Motegi

Shotaro Ito

Eiji Nakatsuno

Toshiaki Ando

Toshiaki Andoh

Hirotada Kaneko

In a heat exchanger of the present invention for exchanging heat between fluid flowing in a flow passage in a heat exchanger tube and fluid flowing outside of said heat exchanger tube, a solid bar-like insertion member or a hollow bar-like insertion member whose opposite ends are closed is provided in said flow passage in which a fluid having phase change flows in gas-liquid two phase state or liquid phase state, a cross section of said insertion member is formed into a substantially circle shape, a polygonal shape or a starlike shape, and a cross-sectional area of a flow passage in which said fluid flows is reduced as a mass flow rate quality of said fluid is reduced. With this construction, it is possible to restrain the pressure loss at the time of evaporation, and the evaporation ability can be enhanced or can be restrained from being deteriorated.

Heat exchanger

A finned heat exchanger includes a plurality of elongated fins which are arranged at a predetermined interval in parallel with one another such that air flows between neighboring ones of the fins in a predetermined direction. A plurality of heat transfer tubes which contain refrigerant passing therethrough are orthogonally inserted through the fins so as to be arranged in a plurality of columns on the fins. When the finned heat exchanger is operated for condensation, the heat transfer tubes are provided in two paths in the vicinity of an inlet for the refrigerant and are provided in one path in the vicinity of an outlet for the refrigerant, such that the heat transfer tubes of the one path occupy about 5 to 30% of all the heat transfer tubes.

Finned heat exchanger

A groove configuration, formed on an inside wall of a heat exchanger tube, has a cross-sectional area varying in the longitudinal direction of the heat exchanger tube. An increased rate of the cross-sectional area is differentiated from a decreased rate of the cross-sectional area by changing the height or top width of a protruding portion, or the depth or bottom width of a recessed portion.

Heat exchanger tube for an air-conditioning apparatus

The fin-tube heat exchanger includes a group of fins arranged parallel to one another at predetermined intervals; cylindrical fin collars formed on each fin at a predetermined column pitch and a predetermined row pitch; and heat transfer tubes extending through the respective fin collars and secured thereto in intimate contact therewith. Seat portions are formed on each fin around the fin collars. A curved protuberance of a generally angular cross-section is formed on the fin adjacent to an outer periphery of each of the seat portions, which has a ridge line of an arcuate or circular shape arranged in concentric relation to the associated fin collar. A plurality of straight protuberances of a generally angular cross-section are formed on each fin adjacent to outer peripheries of the respective seat portions between any two adjacent rows of the fin collars. With this structure, heat transfer performance is improved by a turbulence promoting effect of the straight protuberances. Also an air flow is guided into slip streams behind the heat transfer tubes by the curved protuberances, thereby reducing stagnation zones and increasing the effectively used heat transfer area to improve heat transfer performance.

Fin-tube heat exchanger

A heat exchanger has groups of cutouts provided on tabular fin surfaces, projecting in the direction of arrangement of the fins. Each of the cutouts has two opposed openings in the main direction of air flow as well as two leg portions that not parallel with the main direction of air flow, the cutouts being formed on the tabular fin surfaces alternately on the front and rear sides with a fin base portion placed therebetween. The heat exchanger substantially reduces heat resistance between the air and the fin surfaces and ventilation resistance when the humidity is high, and excels in noise characteristics since the configuration of each cutout provided on the fin surface on the air inlet side of a cross flow fan is changed.

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Otsu, Japan

Osamu Aoyagi