Abstract: A vapor compression cycle system is combined with a Rankine cycle system, with the two systems having a common suction accumulator from which the compressor draws refrigerant vapor for the vapor compression cycle system and from which a pump draws liquid refrigerant for circulation within the Rankine cycle system. The vapor from the Rankine cycle system expander is passed to the compressor discharge to provide a mixture which is circulated within the vapor compression cycle system to obtain improved performance. The heat exchangers are sized so as to obtain a non-complete evaporation, with the resulting two-phase fluid passing to the suction accumulator to provide liquid refrigerant to the Rankine cycle system and vapor refrigerant to the vapor compression cycle system.

Abstract: A combined vapor compression and vapor expansion system uses a common refrigerant which enables a super-critical high pressure portion and a sub-critical low pressure portion of the vapor expansion circuit. Provision is made to combine the refrigerant flow from the vapor expander and from the compressor discharge. The outdoor heat exchanger is so sized and designed that the working fluid discharged therefrom is always in a liquid form so as to provide a liquid into the pump inlet. The pump and expander are so sized and designed that the high pressure portion of the vapor expansion circuit is always super-critical. A topping heat exchanger, liquid to suction heat exchanger, and various other design features are provided to further increase the thermodynamic efficiency of the system.

Abstract: A heat exchanger includes a plurality of flattened, multi-channel heat exchange tubes of generally J-shape extending between an inlet header and an outlet header. Each heat exchange tube has a base bend that extends horizontally between the vertically extending relatively shorter leg, which is in fluid flow communication with the fluid chamber of the inlet header, and the vertically extending relatively longer leg, which is in fluid flow communication with the fluid chamber of the outlet header.

Abstract: A heat exchanger includes a plurality of multi-channel heat exchange tubes extending between spaced inlet and outlet headers. Each heat exchange tube has a plurality of flow channels defining discrete flow paths extending longitudinally in parallel relationship from its inlet end to its outlet end. The inlet header has a channel for receiving a two-phase fluid from a fluid circuit and a chamber for collecting the fluid. The chamber has an inlet in flow communication with the channel and an outlet in flow communication with the plurality of fluid flow paths of the heat exchange tubes. The channel defines a relatively high turbulence flow passage that induces uniform mixing of the liquid phase refrigerant and the vapor phase fluid and reduces potential stratification of the vapor phase and the liquid phase within the fluid passing through the header.

Abstract: A vapor compression cycle system is combined with a Rankine cycle system, with the two systems having a common suction accumulator from which the compressor draws refrigerant vapor for the vapor compression cycle system and from which a pump draws liquid refrigerant for circulation within the Rankine cycle system. The vapor from the Rankine cycle system expander is passed to the compressor discharge to provide a mixture which is circulated within the vapor compression cycle system to obtain improved performance. The heat exchangers are sized so as to obtain a non-complete evaporation, with the resulting two-phase fluid passing to the suction accumulator to provide liquid refrigerant to the Rankine cycle system and vapor refrigerant to the vapor compression cycle system.

Abstract: A parallel flow heat exchanger includes a plurality of connector tubes which fluidly interconnect the individual flat heat exchange tubes to a refrigerant delivery member such that the refrigerant flows along the lengths of the connector tubes and then flows in a direction orthogonal thereto to enter the flat heat exchange tubes to thereby provide improved refrigerant distribution thereto. The refrigerant distribution member may be an inlet manifold or an entrance port or a refrigerant distributor. The connector tubes may be connected so as to conduct the flow in parallel or in series, and an orifice may be placed at the entrance end thereof to improve refrigerant distribution.

Abstract: A gravity-driven pumping unit has an inlet valve connected to a condenser, an outlet valve connected to a boiler, and a staging zone between the inlet and outlet valves. The inlet valve, the outlet valve, the liquid line and entire path established between the condenser and boiler are oriented, sized and shaped to allow for the vapor refrigerant to freely move upward from the boiler to the condenser and to allow for the liquid refrigerant to freely drain downwards from the condenser to the boiler by gravity. A control system opens and closes the inlet and outlet valves in a proper sequence, which enables gravity-driven movement of liquid refrigerant from the condenser to the staging zone and then from the staging zone to the boiler, against a positive pressure differential between the boiler and condenser.

Abstract: The invention relates to refrigerating systems, primarily, to refrigerating systems employing compressors with economizing inlets and multi-pass condensers. In accordance with the invention a refrigerating system with economizing cycle employs a compressor unit with an economizer inlet and a condenser unit having a first condensation stage, a second condensation stage, and means to remove liquid refrigerant portion between the condensation stages. An intermediate liquid outlet from the first condensation stage feeds a circuit with the evaporator and a liquid outlet from the second condensation stage feeds a circuit with the economizer inlet. The invention provides a high efficiency refrigerating system incorporating of advantages of cost-effectiveness provision of liquid sub-cooling or/and liquid temperature inherent for refrigerating systems with economizing cycle and cost-effectiveness advantages of two-stage condensation condensers.

Abstract: A refrigerant system providing enhanced performance over a wider range of operating conditions than traditional economized refrigerant systems. The system includes an economizer branch that connects a liquid outlet from a suction accumulator to an economizer inlet port of a compressor unit. The economizer branch includes a liquid refrigerant pump that delivers a non-evaporated liquid refrigerant portion from the suction accumulator into the economizer heat exchanger, where the liquid refrigerant portion evaporates, increasing thermodynamic potential of the main circuit refrigerant also flowing in through the economizer heat exchanger, and a formed vapor stream is delivered into the economizer inlet port of the compressor unit.

Abstract: A heat exchanger includes an inlet header, an outlet header and a plurality of flat, multi-channel heat exchange tubes extending therebetween. A longitudinally extending member divides the interior of the header into a first chamber on one side thereof for receiving a fluid and a second chamber on the other side thereof. A plurality of multi-channel heat exchange tubes extend between the headers with the respective inlet end of each heat exchange tube passing into the second chamber of the inlet header. Fluid passes through a series of longitudinally spaced openings in the longitudinally extending member for distribution to the inlets to the channels of the multi-channel heat exchange tubes. The fluid may undergo expansion as it passes through the openings.

Abstract: A heat exchanger includes a plurality of flat, multi-channel heat exchange tubes extending between spaced headers. Each heat exchange tube has an inlet end in fluid flow communication with one of the headers and an outlet opening to the other header. Each heat exchange tube has a plurality of flow channels extending longitudinally in parallel relationship from its inlet end to its outlet end. A plurality of connectors are positioned between the inlet header and the heat transfer tubes to define a flow path providing fluid flow communication between the inlet header and the inlet ends of the heat exchange tubes. Two or more flow restriction ports are arranged in the series in the flow path through each connector whereby fluid flowing from the inlet header to the flow channels of the heat exchange tube associated therewith undergoes an expansion as the fluid passes through each flow restriction port.

Abstract: A heat exchanger includes an inlet header, an outlet header and a plurality of flat, multi-channel heat exchange tubes extending therebetween. A longitudinally extending member divides the interior of the header into a first chamber on one side thereof for receiving a fluid and a second chamber on the other side thereof. A plurality of multi-channel heat exchange tubes extend between the headers with the respective inlet end of each heat exchange tube passing into the second chamber of the inlet header. Fluid passes through a series of longitudinally spaced openings in the longitudinally extending member for distribution to the inlets to the channels of the multi-channel heat exchange tubes. The fluid may undergo expansion as it passes through the openings.

Abstract: A heat exchanger includes a plurality of flat, multichannel heat exchange tubes extending between spaced headers. Each heat exchange tube has an inlet end in fluid flow communication with one of the headers and an outlet opening to the other header. Each heat exchange tube has a plurality of flow channels extending longitudinally in parallel relationship from its inlet end to its outlet end. A plurality of connectors are positioned between the inlet header and the heat transfer tubes to define a flow path providing fluid flow communication between the inlet header and the inlet ends of the heat exchange tubes. Two or more flow restriction ports are arranged in the series in the flow path through each connector whereby fluid flowing from the inlet header to the flow channels of the heat exchange tube associated therewith undergoes an expansion as the fluid passes through each flow restriction port.

Abstract: A comb-like insert having a body and plurality of tapered fingers is installed with its fingers disposed within respective minichannels. The fingers and their respective minichannels are so sized as to restrict the channels and frictionally hold the insert in place in one dimension while providing for gaps in another dimension such that the flow of refrigerant is somewhat obstructed but allowed to pass through the gaps between the insert fingers and the minichannel walls and then expand as it passes along the tapered fingers to thereby provide a more homogenous mixture to the individual minichannels. A provision is also made to hold the insert in its installed position by way of internal structure within the inlet manifold. In one embodiment, an internal plate is provided for that purpose, and the plate has openings formed therein for the equalization of pressure on either side thereof.

Abstract: In a refrigeration system having a pressurizer, a condenser, an expansion device and an evaporator, with the evaporator having an inlet header, an outlet header, and a plurality of channels therebetween, the outlet header has a liquid outlet and a vapor outlet and provision is made for separation of refrigerant liquid from refrigerant vapor. The liquid refrigerant is passed through a superheating heat exchanger to obtain complete evaporation and superheating prior to passing to the pressurizer. Various other features are provided to enhance the system operation.

Abstract: A parallel flow (minichannel or microchannel) evaporator includes a porous member inserted at the entrance of the evaporator channels which provides refrigerant expansion and pressure drop controls resulting in the elimination of refrigerant maldistribution and prevention of potential compressor flooding.