A heat exchanger includes a plurality of principal heat exchange sections and auxiliary heat exchange sections. Each of the auxiliary heat exchange sections is in series connection to a corresponding one of the principal heat exchange sections. Of tube number ratios of the number of the flat tubes constituting each of the heat exchange sections to the number of the flat tubes constituting a corresponding one of the auxiliary heat exchange sections, the first principal heat exchange sections which is the lowermost one has the smallest tube number ratio. Consequently, discharge of liquid refrigerant from a lower portion of the first principal heat exchange section is accelerated during defrosting, thereby shortening the time required for defrosting.

Heat exchanger comprising a pair of headers and a plurality of parallel and coplanar tubes interconnecting the headers, wherein each header comprises a header plate provided with a plurality of slots, in each of which an end of a respective tube is fitted, and wherein the heat exchanger is configured to prevent fluid from flowing into at least one tube, hereinafter dummy tube, arranged at a boundary between functionally different sections of the heat exchanger. The slot of the header plate which receives the end of the respective dummy tube is formed as a blind recess in the header plate.

Heat exchanger assemblies for electronic devices are disclosed. A heat exchanger assembly may include a heat transfer body that has a face that forms open passageways. A cover structure may be attached to the heat transfer body in a manner to enclose the open passageways, thereby forming a heat exchanger assembly that includes enclosed fluid conduits. In this regard, the enclosed fluid conduits may form complex and intricate patterns within the heat exchanger assembly that are tailored to the heat requirements of a particular application. Heat exchanger assemblies as described herein may be thermally coupled to a center waveguide section of a spatial power-combining device. The enclosed fluid conduits may be tailored based on locations of amplifiers within the center waveguide section to provide improved thermal operation of the spatial power-combining device.

A polymer tube dry cooling tower designed to operate with internal fluid at or near atmospheric pressure.

A system includes a first set of coils receive coolant from a first coolant line and provide the coolant to a second coolant line. A second set of coils receive coolant from a third coolant line and provide the coolant to a fourth coolant line. A first valve regulates flow of coolant between the first and third coolant line. A second valve regulates flow of coolant between the second and the fourth coolant lines. A third valve regulates flow of coolant between the fourth coolant line and a fifth coolant line coupled to a water evaporator and a three-way valve. The three-way valve regulates flow of coolant between the fifth coolant line, the third coolant line, and a coolant input line. A fourth valve regulates flow of coolant between the second coolant line and a water condenser. A controller adjusts the valves to operate in an intermediate temperature mode.

Apparatuses, systems and methods implementing a multi-coil heat exchanger are directed to providing good heat transfer performance, capacity, and efficiency, and while reducing pressure drop through multi-coil microchannel evaporators. The multi-coil heat exchanger in some examples is a multi-coil microchannel evaporator. The multi-coil microchannel evaporator can be implemented in a refrigerant system that is a single circuit, where the multi-coil microchannel evaporator is an air to refrigerant type heat exchanger. The multi-coil microchannel evaporator includes a distribution to the multiple coils of the multi-coil microchannel evaporator, where the distribution includes one or more separations to transmit refrigerant to each of the coils of the multi-coil microchannel evaporator and one or more junctions to transmit refrigerant from the coils.

A refrigerator includes a body, first and second storage compartments and a machine compartment formed in the body, a blower fan disposed in the machine compartment, first and second refrigerating units comprising first and second compressors to compress first and second refrigerants, respectively, first and second condensers to condense the first and second refrigerants, respectively, first and second expansion valves to expand the first and second refrigerants, respectively, and first and second evaporators to evaporate the first and second refrigerants, respectively, the first and second refrigerating units supplying cold air to the first and storage compartments, respectively. The first compressor, the second compressor, and the first condenser are disposed in the machine compartment and are cooled by forcible flow of air caused by the blower fan, and the second condenser is disposed outside the machine compartment and is cooled by natural convection of air.

A U-bend pipe type heat exchanger includes: a heat exchanger main body surrounded by a front side plate, a back side plate, a left side plate, and a right side plate, and having open upper and lower portions through which a heat source passes; a plurality of U-bend pipes inserted between the left side plate and the right side plate, each of the plurality of U-bend pipes including two heat exchange pipes arranged in parallel with each other and a U-shaped pipe connecting one end portions of the two heat exchange pipes; and a plurality of water jackets attached to at least one of outward surfaces of the left side plate and the right side plate, and connecting open end portions of two adjacent heat exchange pipes such that a low-temperature water circulates along the plurality of U-bend pipes.

An improved water management system with improved airflow distribution for counterflow evaporative heat exchangers is provided. Such heat exchangers include open cooling towers, closed circuit cooling towers, and evaporative condensers. The improved water management system eliminates water splash out and the noise associated with water splashing. Further when the fan assemblies are located below the evaporative heat exchanger, the improved water management system keeps the fans dry and prevents freezing in subzero climates.

A heat exchanger includes fins each housed in a respective one of tubes. Each of the fins includes a connecting portion that corrugated for a predetermined fin pitch and that has peaks joined to an inner surface of a wall of each of the tubes and a non-connecting portion that is not joined to the inner surface of the wall of the each of the tubes. The non-connecting portion has a length longer than the predetermined fin pitch. The wall of the each of the tubes has a protrusion to face the non-connecting portion.