A heat exchanger for an air conditioner for which a zeotropic refrigerant mixture is used is obtained, and the heat exchanger, when used as an evaporator, enables reduction of the amount of required refrigerant without deteriorating the heat transfer performance. The heat exchanger includes: a plurality of fins stacked together at predetermined intervals therebetween; first heat transfer pipes which extend through the plurality of fins, in which a heat medium flows, and which have a plurality of grooves in the inner surface of the pipes; and second heat transfer pipes extending through the plurality of fins, having one end connected to one end of the first heat transfer pipes to form one heat medium flow path, being smaller in pipe diameter than the first heat transfer pipes, and having an inner surface shape providing a pressure loss per unit length smaller than that of the first heat transfer pipes.

A heat exchanger for an air conditioner for which a zeotropic refrigerant mixture is used is obtained, and the heat exchanger, when used as an evaporator, enables reduction of the amount of required refrigerant without deteriorating the heat transfer performance. The heat exchanger includes: a plurality of fins stacked together at predetermined intervals therebetween; first heat transfer pipes which extend through the plurality of fins, in which a heat medium flows, and which have a plurality of grooves in the inner surface of the pipes; and second heat transfer pipes extending through the plurality of fins, having one end connected to one end of the first heat transfer pipes to form one heat medium flow path, being smaller in pipe diameter than the first heat transfer pipes, and having an inner surface shape providing a pressure loss per unit length smaller than that of the first heat transfer pipes.

Apparatus and methods for jet impingement cooling are provided. In one arrangement, a fluid channelling structure engages against a target surface to define a flow volume. Fluid is jetted onto the target surface from inlets and is removed via outlets. Flow directing features form a plurality of channels with no straight paths between inlets and outlets. A time averaged flow direction of fluid in contact with each flow directing feature is more nearly perpendicular to a direction of jetting of the fluid from a nearest inlet than parallel to the direction of jetting One or more pairs of the inlets and outlets are such that a majority of fluid jetted onto the target surface from the inlet of the pair will be removed from the flow volume through the outlet of the same pair.

Apparatus and methods for jet impingement cooling are provided. In one arrangement, a fluid channelling structure engages against a target surface to define a flow volume. Fluid is jetted onto the target surface from inlets and is removed via outlets. Flow directing features form a plurality of channels with no straight paths between inlets and outlets. A time averaged flow direction of fluid in contact with each flow directing feature is more nearly perpendicular to a direction of jetting of the fluid from a nearest inlet than parallel to the direction of jetting One or more pairs of the inlets and outlets are such that a majority of fluid jetted onto the target surface from the inlet of the pair will be removed from the flow volume through the outlet of the same pair.

The present invention relates to internally profiled variable pitch tubes or pipes made of steel. The terms tube and pipe are used synonymously in the context of this invention. These tubes are used in the petrochemical industry to crack oil, gas and shale feedstocks into simple hydrocarbons such as ethylene and similar products.

An eddy fluid heat exchange device comprises a compound tube assembly mounted with an eddy guiding structure. The compound tube assembly comprises an outer tube mounted with an inner tube. The outer tube and the inner tube have an eddy passage along an axis of the inner tube formed therebetween. The outer tube has a guiding exit at one end of the eddy passage. The eddy guiding structure is mounted at another end of the eddy passage, having a guiding entrance. Entering from the guiding entrance, high pressure fluid forms eddies surrounding the inner tube when flowing through the eddy guiding structure. A flowing path of the high pressure fluid in the eddy passage extends, simplifying structures and lowering costs of production and maintenance. Besides, increasing a heat transfer area between the high pressure fluid and the outer tube or the inner tube improves the heat transfer efficiency.

An eddy fluid heat exchange device comprises a compound tube assembly mounted with an eddy guiding structure. The compound tube assembly comprises an outer tube mounted with an inner tube. The outer tube and the inner tube have an eddy passage along an axis of the inner tube formed therebetween. The outer tube has a guiding exit at one end of the eddy passage. The eddy guiding structure is mounted at another end of the eddy passage, having a guiding entrance. Entering from the guiding entrance, high pressure fluid forms eddies surrounding the inner tube when flowing through the eddy guiding structure. A flowing path of the high pressure fluid in the eddy passage extends, simplifying structures and lowering costs of production and maintenance. Besides, increasing a heat transfer area between the high pressure fluid and the outer tube or the inner tube improves the heat transfer efficiency.

An eddy fluid heat exchange device comprises a compound tube assembly mounted with an eddy guiding structure. The compound tube assembly comprises an outer tube mounted with an inner tube. The outer tube and the inner tube have an eddy passage along an axis of the inner tube formed therebetween. The outer tube has a guiding exit at one end of the eddy passage. The eddy guiding structure is mounted at another end of the eddy passage, having a guiding entrance. Entering from the guiding entrance, high pressure fluid forms eddies surrounding the inner tube when flowing through the eddy guiding structure. A flowing path of the high pressure fluid in the eddy passage extends, simplifying structures and lowering costs of production and maintenance. Besides, increasing a heat transfer area between the high pressure fluid and the outer tube or the inner tube improves the heat transfer efficiency.

An eddy fluid heat exchange device comprises a compound tube assembly mounted with an eddy guiding structure. The compound tube assembly comprises an outer tube mounted with an inner tube. The outer tube and the inner tube have an eddy passage along an axis of the inner tube formed therebetween. The outer tube has a guiding exit at one end of the eddy passage. The eddy guiding structure is mounted at another end of the eddy passage, having a guiding entrance. Entering from the guiding entrance, high pressure fluid forms eddies surrounding the inner tube when flowing through the eddy guiding structure. A flowing path of the high pressure fluid in the eddy passage extends, simplifying structures and lowering costs of production and maintenance. Besides, increasing a heat transfer area between the high pressure fluid and the outer tube or the inner tube improves the heat transfer efficiency.

An active vortex generator adapts to a flow rate of fluid through and/or a heat flux applied through a heat exchanger channel to improve the heat transfer rate of the heat exchanger. In some implementations, the movement of the active vortex generator may be induced by the fluid flow through the heat exchanger channel. In some implementations, the movement of the active vortex generator may be induced through an externally applied force on the active vortex generator. An actuated active vortex generator is particularly suited to heat exchangers with high heat flux dissipation requirements. Locating an actuated active vortex generator proximate to such high heat flux dissipation locations provides for improved heat transfer that can be activated when needed, such as upon operation of a high heat flux component.