Abstract: An evaporator for an air conditioning system includes a plurality of clamshell plates stacked in series along a longitudinal axis and a plurality of core tubes coupled with the stacked clamshell plates. In an upper region of the evaporator, the stacked clamshell plates form an inlet tank and an outlet tank hydraulically communicated with the core tubes for a refrigerant flow. Each of the clamshell plates includes a pooling ridge on a first surface of the clamshell plate for pooling a liquid refrigerant by gravity such that the liquid refrigerant is evenly distributed to inlet core tubes disposed along the longitudinal axis.

Abstract: A heat exchanger includes a header, a plurality of tubes, and a distributor. The header is configured to define an inlet for the heat exchanger. The tubes extend away from and are fluidicly coupled to the header. The distributor is located within the header and is configured to distribute refrigerant flowing along a longitudinal axis from the inlet to the tubes via a plurality of openings defined by the distributor through a wall of the distributor. The openings include a first opening configured to direct refrigerant in a first direction, and a second opening configured to direct refrigerant in a second direction. The first direction and the second direction are selected such that refrigerant emitted from the first opening and the second opening substantially intersect each other.

Abstract: Disclosed is a unitary heat pump air conditioner (HPAC) system having a refrigerant diversion loop configured to supply sufficient heat to defrost an external heat exchanger while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system includes a refrigerant loop configured to pump heat from a cold coolant loop that scavenges heat from the external heat exchanger to a hot coolant loop that supplies heat to the passenger compartment. The refrigerant loop includes a condenser in thermal communication with the hot coolant loop, evaporator in thermal communication with the cold coolant loop, and a compressor to cycle the refrigerant through the refrigerant loop. The refrigerant loop further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor directly to the evaporator to heat the cold coolant loop sufficient to defrost the external heat exchanger.

Abstract: An internal heat exchanger assembly for an air conditioning system, having a housing defining a cylindrical with opposing ends. The ends are sealed with end caps having inlets/outlets. A helical coil tube is coaxially disposed within the cylindrical cavity, in which the helical coil includes two tube ends extending in opposing directions and exiting the cylindrical cavity through tube ports provided in the end caps. A twisted elongated strip is coaxially disposed within the cylindrical cavity extending from the first end to the second end. The twisted elongated strip includes a plurality of radially extending fingers adapted to engage the helical coil to maintain the helical coil in a predetermined position.

Abstract: An automotive evaporator heat exchanger is provided having a hybrid expansion device configured to aliquot refrigerant across the refrigerant tubes. The hybrid expansion device includes a first stage refrigerant pressure drop device and a second stage refrigerant pressure drop device. The first stage refrigerant pressure drop device is a TXV configured to receive and expand a liquid phase refrigerant into a first mixture of two phase refrigerant and the second stage refrigerant pressure drop device is a tube extending within the inlet manifold configured to expand the first mixture of two phase refrigerant into a second mixture of two phase refrigerant. The tube includes a plurality of orifices and a tube diameter large enough to prevent resistance to refrigerant flow, but, small enough to prevent the first mixture of two phase refrigerant flow from separating into liquid and vapor strata.

Abstract: A heat exchanger includes a header, a plurality of tubes, and a distributor. The header is configured to define an inlet for the heat exchanger. The tubes extend away from and are fluidicly coupled to the header. The distributor is located within the header and is configured to distribute refrigerant flowing along a longitudinal axis from the inlet to the tubes via a plurality of openings defined by the distributor through a wall of the distributor. The openings include a first opening configured to direct refrigerant in a first direction, and a second opening configured to direct refrigerant in a second direction. The first direction and the second direction are selected such that refrigerant emitted from the first opening and the second opening substantially intersect each other.

Abstract: A two-pass evaporator suitable for use in an automobile includes various pressure drop devices to aliquot refrigerant into tubes that make up the two-pass evaporator. The two-pass evaporator includes a first pressure-drop device configured to receive and expand a liquid phase refrigerant into a first mixture of two-phase refrigerant; and a second pressure-drop device configured to receive and expand the first mixture of two-phase refrigerant into a second mixture of two-phase refrigerant and aliquot the second mixture of two-phase refrigerant to the first end of the first plurality of tubes. The two-pass evaporator includes a transition manifold that may house a flow-modulation plate disposed therein and configured to segregate the transition manifold into an upstream portion and a downstream portion. The flow-modulation device works in conjunction with the upstream pressure drop devices to aliquot refrigerant from the first plurality of tubes to the second plurality of tubes.

Abstract: An internal heat exchanger assembly for an air conditioning system, having a substantial cylindrical cavity in which a helical coil tube is coaxially disposed within the cylindrical cavity. A bleed valve assembly is incorporated into the helical coiled tube, in which the bleed valve assembly is adapted to open at a predetermined differential pressure between the high pressure side and low pressure side of the internal heat exchanger. The bleed valve selectively bleeds refrigerant from the high pressure side to the low pressure side, thereby increasing the pressure and mass flow rate of the refrigerant to the suction side of a compressor.

Abstract: An automotive evaporator heat exchanger is provided having a hybrid expansion device configured to aliquot refrigerant across the refrigerant tubes. The hybrid expansion device includes a first stage refrigerant pressure drop device and a second stage refrigerant pressure drop device. The first stage refrigerant pressure drop device is a TXV configured to receive and expand a liquid phase refrigerant into a first mixture of two phase refrigerant and the second stage refrigerant pressure drop device is a tube extending within the inlet manifold configured to expand the first mixture of two phase refrigerant into a second mixture of two phase refrigerant. The tube includes a plurality of orifices and a tube diameter large enough to prevent resistance to refrigerant flow, but, small enough to prevent the first mixture of two phase refrigerant flow from separating into liquid and vapor strata.

Abstract: Disclosed is a unitary heat pump air conditioner (HPAC) system having a refrigerant diversion loop configured to supply sufficient heat to defrost an external heat exchanger while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system includes a refrigerant loop configured to pump heat from a cold coolant loop that scavenges heat from the external heat exchanger to a hot coolant loop that supplies heat to the passenger compartment. The refrigerant loop includes a condenser in thermal communication with the hot coolant loop, evaporator in thermal communication with the cold coolant loop, and a compressor to cycle the refrigerant through the refrigerant loop. The refrigerant loop further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor directly to the evaporator to heat the cold coolant loop sufficient to defrost the external heat exchanger.

Abstract: An internal heat exchanger assembly for an air conditioning system, having a substantial cylindrical cavity in which a helical coil tube is coaxially disposed within the cylindrical cavity. A bleed valve assembly is incorporated into the helical coiled tube, in which the bleed valve assembly is adapted to open at a predetermined differential pressure between the high pressure side and low pressure side of the internal heat exchanger. The bleed valve selectively bleeds refrigerant from the high pressure side to the low pressure side, thereby increasing the pressure and mass flow rate of the refrigerant to the suction side of a compressor to reduce or eliminate compressor rattle.

Abstract: An internal heat exchanger assembly for an air conditioning system, having a housing defining a cylindrical with opposing ends. The ends are sealed with end caps having inlets/outlets. A helical coil tube is coaxially disposed within the cylindrical cavity, in which the helical coil includes two tube ends extending in opposing directions and exiting the cylindrical cavity through tube ports provided in the end caps. A twisted elongated strip is coaxially disposed within the cylindrical cavity extending from the first end to the second end. The twisted elongated strip includes a plurality of radially extending fingers adapted to engage the helical coil to maintain the helical coil in a predetermined position.