A heat exchanger which may be used in an engine, such as a vehicle engine for an aircraft or orbital launch vehicle. is provided. The heat exchanger may be configured as generally drum-shaped with a multitude of spiral sections, each containing numerous small diameter tubes. The spiral sections may spiral inside one another. The heat exchanger may include a support structure with a plurality of mutually axially spaced hoop supports, and may incorporate an intermediate header. The heat exchanger may incorporate recycling of methanol or other antifreeze used to prevent blocking of the heat exchanger due to frost or ice formation.

A heat exchanger includes multiple tubes and multiple fins. Each of the tubes has a tubular shape extending in a horizontal direction. Each of the fins is disposed between adjacent ones of the tubes in a vertical direction vertical to the horizontal direction. Each of the fins is corrugated and includes bent portions located near the adjacent ones of the tubes and flat plate portions each of which extends in the vertical direction to connect between two of the bent portions. Each of the fins includes a pair of slits and an offset portion. At least a portion of the pair of slits extends to one of the bent portions. The offset portion is formed by having a portion of each of the fins between the pair of slits recessed inward of the one of the bent portions.

A heat exchanger includes: a plurality of tubes arranged in an up-down direction; and a reinforcing plate arranged on a lower side of a lowermost tube of the plurality of tubes. The reinforcing plate has a bent portion protruding downward and extending along a longitudinal direction of the tube. The bent portion includes at least one discharge hole to discharge a condensed water. The discharge hole is formed by an upstream rib extending from the upper side toward the discharge hole in an upstream region and a downstream rib extending from the upper side toward the discharge hole in a downstream region, and a height dimension of the upstream rib is different from a height dimension of the downstream rib at least partially along a longitudinal direction of the tube.

A heat exchanger, including a heat exchanger tube for guiding a first medium in its interior, and also at least one connection for a second medium, wherein the region around the heat exchanger tube is provided by an open-pored, in particular solid, material, preferably a body of such a material, into which the second medium in particular can enter.

A defrosting system for defrosting an evaporator assembly is disclosed. The system includes the evaporator assembly, an electrically resistive coating having an electrically insulative matrix and a conductive doping agent disposed on at least one surface of the evaporator assembly, and a plurality of electrical terminals arranged and disposed to supply electricity to the electrically resistive coating. A method for defrosting an evaporator assembly and a coating for heating evaporator assemblies are also disclosed.

A method of operating a heat exchanger is disclosed in which an electric field is applied to a hydrophobic surface having condensed water droplets thereon to reduce a contact angle between the individual droplet surfaces and the hydrophobic surface, and to increase droplet surface energy to a second surface energy level. The electric field is removed to increase the contact angle between the individual droplet surfaces and the hydrophobic surface, and to reduce droplet surface energy to a third surface energy level. The third surface energy level is greater than the first surface energy level and greater than a surface energy level for a free droplet. A portion of the droplet surface energy is converted to kinetic energy to detach droplets from the hydrophobic surface. The detached droplets are removed from the heat rejection side fluid flow path.

A heat exchanger for heat exchange between air and a heat exchange medium includes a plurality of heat transfer conduits arranged parallel to each other as flow paths for the heat exchange medium and a plurality of fin members. The fin members are configured to provide: an air inlet end for air inflow, an air outlet end for air outflow, and an air flow path. The air flow path connects the air inlet end with the air outlet end and allows a heat exchange with the plurality of heat transfer conduits. Each fin member includes a plurality of undulation troughs coplanar with each other and connected together so as to define a water condensate flow path. Each water condensate flow path has a flat bottom which extends from the air inlet end to the air outlet end.

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.

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.

A combination refrigeration displacement and drain device is disclosed that can be mounted within a heat exchanger, such as a shell and tube heat exchanger, which may be used for example as a heat exchanger in a chiller unit, which may be used in an HVAC or refrigeration system. One example of such components can include heat exchangers, such as for example a condenser employing a gravity drain. Advantageously, the combination refrigeration displacement and drain device herein can provide a refrigerant charge reduction for example that is used in the chiller unit, while facilitating drainage out of the heat exchanger. The combination refrigeration displacement and drain device can alleviate the liquid refrigerant accumulation that may normally be necessary to induce flow in a gravity drain design.