Abstract: A cooling system that has a heat exchanger which is housed in one enclosure and is constituted of a plurality of heat exchange modes, and the heat exchanger includes a refrigerant forced circulation mode, a refrigerant natural circulation mode, and a ventilation mode. A temperature detector performs switching to an optimal mode, to thereby cool the inside of the enclosure of a housing accommodating equipment including a heat-generating component.

Abstract: A cooling system of the invention has heat exchange means which is housed in one enclosure (31) and is constituted of a plurality of heat exchange modes, and the heat exchange means includes a refrigerant forced circulation mode, a refrigerant natural circulation mode, and a ventilation mode. Temperature detection means performs switching to an optimal mode, to thereby cool the inside of the enclosure (31) of a housing (30) accommodating equipment (32) including a heat-generating component (33).

Abstract: A cooling system for a communication station for cooling a casing of the communication relay station, accommodating communication equipments including heat components, by a boiling-type cooler in a natural circulation refrigerating circuit and an evaporator in a forced circulation refrigerating circuit, activated by a compressor comprising: a common airflow path having a heated air intake port for taking a heated air in the casing; and a common fan for sending an air to the boiling-type cooler and the evaporator, wherein the boiling-type cooler, the evaporator, and the common fan are built in a common airflow path.

Abstract: In an air conditioning system of the type having air volume to each room controlled by individual dampers the improvement comprising a damper control unit for, on a trial mode, gradually changing the opening angle of each damper while the other dampers are kept fully closed; air volume measurement unit for detecting the air volume from a blower to measure the actual air volume; pressure difference measurement unit for detecting a difference in pressure between the outlet air and the inlet air of an indoor heat exchanger unit to measure an air feeding pressure difference with respect to an actual duct system; air volume calculation unit for finding the relationship among the air volume passing through the respective dampers, the opening angles of the respective dampers and the air feeding pressure difference, based on outputs from the pressure difference measurement unit, the air volume measurement unit and the damper control unit, to find air feeding resistance in the respective ducts.

Abstract: A heat exchanger is disclosed, which comprises a plurality of heat-transfer elements (1) placed side by side each of which has more than one through-hole (3) and which are cyclically bent in a generally trapezoidal wave form in the direction of the flow of a fluid, the bends in one heat-transfer element (1 ) being in phase with those in an adjacent heat-transfer element (1) in such a manner that the main stream of said fluid will flow not through the holes in each of said heat-transfer elements (1) but through the passage formed by adjacent heat-transfer elements (1). This arrangement not only provides improved heat-transfer characteristics; it also serves to offer a lighter product because of the presence of throught-holes (3).

Abstract: A heat exchanger is disclosed, which comprises a plurality of heat-transfer elements (1) placed side by side each of which has more than one through-hole (3) and which are cyclically bent in a generally trapezoidal waveform in the direction of the flow of a fluid, the bends in one heat-transfer element (1) being out of phase with those in an adjacent heat-transfer element (1) by one-half cycle in such a manner that the main stream of said fluid will flow not through the holes in each of said heat-transfer elements (1) but through the passage formed by adjacent heat-transfer elements (1). This arrangement serves to provide improved heat-transfer characteristics.

Abstract: A heat exchanger comprises a plurality of regularly corrugated fins placed one over another in layers at regular pitches in a back-to-back arrangement so as to form alternate wide and narrow fluid passage between the adjacent corrugated fins, and each having a plurality of small through holes, a plurality of collars formed in a staggered arrangement, and an annular area not having any small through hole and formed so as to surround the root of each collar; and pipes for passing a secondary fluid therethrough, each inserted through the collars of the layers of the corrugated fins. The height of the collar from the lower surface of the annular area corresponds to the pitch between the adjacent corrugated fins, and thereby the corrugated fins can be assembled at regular pitches simply by placing one over another. The pipes are expanded after being inserted through the collars so that the pipes are firmly and closely joined to the collars for satisfactory heat transmission between the fins and the pipes.

Abstract: A heat exchanger comprises a plurality of perforated and regularly corrugated heat transfer plates arranged in a ridge-to-ridge and furrow-to-furrow arrangement, so as to form primary fluid passages each consisting of alternate expanded sections and narrowed sections arranged along the direction of flow of a primary fluid, and a plurality of pipes for passing a secondary fluid therethrough, the pipes penetrating through and across the heat transfer plates. Oblique guide grooves are formed in the surfaces of each heat transfer plates to facilitate the downward flow of the condensate condensed over the surfaces of the heat transfer plates, the grooves being inclined closer to the vertical than to the horizontal to facilitate downward flow of any vapor condensed on the plates from the primary fluid whereby the heat transfer plates dry quickly for efficient heat exchange between the primary and secondary fluids.

Abstract: A plate-fin-tube type heat exchanger is constructed with a multitude of plate fins juxtaposed one another and a plurality of heat transmitting tubes passing through said plate fins and being held thereby. A plurality of cut and raised pieces are formed to intersect orthogonally with the air flowing direction at both front and rear surfaces of said plate fins with a certain space interval among them in the air flowing direction and at a location between the adjacent heat transmitting tubes arranged in the longitudinal direction of said plate fins, and then the edge portion on both sides of each cut and raised piece is re-bent in the direction opposite to the lifting direction of said piece and in substantially parallel with the surface of said plate fin so that the cross-section of said cut and raised piece may assume a sloping form in the direction of the air flow and that fin base plate portion may be present between the adjacent cut and raised pieces in parallel with the air flow.

Abstract: A cold storage and refrigeration system includes a single refrigerator, a plurality of cold storage and refrigeration units having evaporators, respectively, connected to the refrigerator for passage therethrough of a refrigerant when the refrigerator is in operation, a plurality of temperature sensors installed respectively in the cold storage and refrigeration units for detecting first and second levels of temperature respectively therein, and a control unit responsive to signals supplied from the temperature sensors for controlling the refrigerator in order to energize the latter in response to the detection of the first temperature level by one of the temperature sensors when the refrigerator is de-energized, whereby the refrigerant can flow through the evaporators simultaneously. With this arrangement, the refrigerator can remain de-energized for an increased interval of time during operation of the system, and hence consumes a reduced amount of electric power.