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: The disclosure relates to a unitary heat pump air conditioner (Unitary HPAC) having a plate type hot-side heat exchanger assembly, a cold-side heat exchanger assembly, and electrically driven compressors and coolant pumps. The plate type hot-side heat exchanger assembly includes a plurality of plates stacked and hermetically sealed between an upstream end plate and a downstream end plate, defining a condenser/chiller portion having a first coolant passageway, a sub-cooler portion having a second coolant passageway, and a refrigerant receiver portion sandwiched between the condenser/chiller portion and the sub-cooler portion. The first coolant passageway and the second coolant passageway are in non-contact thermal communication with the refrigerant passageway.

Abstract: A method of fabricating a folded evaporator tube includes providing a tube with a plurality of webs extending between interior surfaces of the tube. The webs are oriented at an angle between forty-five degrees (45°) and sixty degrees (60°) of angle relative to a bottom wall of the tube. A cutting-device that includes a knife and a guide that cooperate to cut the tube to a desired length is also provided. The knife has a point that is forced in a direction parallel to a wall of the tube. The guide defines an opening that conforms to the tube to maintain the shape of the tube during cutting by the knife. The knife further defines a bottom and top edges that extend away from the point and cooperates with the opening to shear the bottom and top walls of the tube along with internal webs inside the tube.

Abstract: An automotive HVAC system includes upper and lower mode cases configured to discharge separate streams of temperature-conditioned air into front and rear passenger zones. The system separates the inlet air into separate mixing chambers, and a third stream through a heater core. Blend doors control hot and cold air streams entering their respective mixing chambers. Operation is controlled by reading requested temperature, blower rate and mode for system zone outlet, converting requests to a flowrate, calculating total flowrate as a summation of all requests, employing a math model to calculate total zonal flowrate as a summation of all zonal flowrates, calculating a blower control error as a function of the difference between total blower request and total zonal flowrate, modifying the operating state using the calculated control error, positioning and resetting the mode valves into defrost, heater and vent openings, and resetting the mode valves.

Abstract: HVAC unit has a single blower fan, an evaporator downstream of the blower and a heater downstream of the evaporator, wherein each zone outlet includes a temperature mixing door for controlling portions of hot and cold air and an output valve for controlling a zonal output flow rate. A method is devised to control the discharge of temperature-conditioned air from a plurality of zone outlets of an automotive HVAC system via such an HVAC unit by the steps of reading an operator-requested zonal discharge blower level for each of the zone outlets; converting each zonal discharge blower level request to a zonal flowrate request; calculating a total requested output flowrate as a summation of all zonal flowrate requests; and adjusting a blower voltage to a minimum voltage required for generating the total requested output flowrate.

Abstract: A heating, ventilation, and air conditioning (HVAC) system for a vehicle includes an evaporator and a diffuser. The evaporator is configured to cool air passing through the evaporator. The diffuser is configured to direct a first portion of the air entering the diffuser through a first section of the evaporator, and direct a second portion of the air entering the diffuser through a second section of the evaporator. The evaporator and the diffuser are configured to cooperate such that air exits the first section at a first temperature and air exits the second section at a second temperature less than the first temperature.

Abstract: A thermoelectric heat exchanger includes a tube, a fin, and a thermoelectric assembly. The tube is configured to contain coolant flowing therethrough and thermally couple the coolant to a surface of the tube. The fin is configured to transfer heat from the fin to air passing across the fin. The thermoelectric assembly is thermally coupled to the tube and the fin. The assembly is configured to heat the fin relative to the tube in response to a voltage source applied to the assembly. The assembly includes a plurality of thermoelectric modules. Each of the thermoelectric modules is electrically interconnected into a group of series connected modules. The number of modules in each group that are electrically connected in series is determined based on a voltage value of the voltage source and a local temperature difference between the tube and the fin proximate to the group.

Abstract: A heating, ventilation, and air conditioning (HVAC) system is configured for use in a vehicle. A first air moving device blowing air through a heat exchanger provides a first airstream having a first temperature to a second air moving device configured to generate a second airstream having a second temperature that is different from the first temperature. The second airstream is a mixture of the first airstream and cabin air that is drawn from a rear portion of the vehicle cabin. The second air moving device may be disposed in the rear portion of the vehicle. The HVAC system further includes a nozzle that is configured to direct the second airstream toward an occupant in the rear portion of the vehicle cabin to provide spot conditioning.

Abstract: An evaporator having a manifold and a plurality of refrigerant tubes extending downward in the direction of gravity from the manifold. The evaporator includes at least one PCM housing engaging the upper portion of the refrigerant tube for storing a phase change material. When operating in a first operating mode, heat is transferred from the phase change material to the refrigerant to freeze and cool the phase change material. When operating in a second operating mode, heat is transferred from the refrigerant to the frozen phase change material to condense the refrigerant. The condensed refrigerant falls downwardly through the tubes and receives heat from a flow of air to cool the air and evaporate the refrigerant. The evaporated refrigerant rises upwardly back to the low pressure of the cold manifold.

Abstract: The disclosure relates to a unitary heat pump air conditioner (Unitary HPAC) having a plate type exchanger assembly, an electrically driven compressor, and coolant pumps. The plate heat exchanger assembly includes a plurality of plates stacked and hermetically sealed between an upstream end plate and a downstream end plate. The stacked plates define a condenser/chiller portion adjacent the upstream end plate, an accumulator portion adjacent the downstream end plate, and an evaporator/chiller portion sandwiched between the condenser/chiller portion and the accumulator portion. A refrigerant passageway extends through the plate type heat exchanger assembly, a hot coolant passageway extends through the condenser/chiller portion, and a cold coolant passageway extends through the evaporator/chiller portion. The cold coolant passageway and the hot coolant passageway are in non-contact thermal communication with the refrigerant passageway.

Abstract: A thermoelectric heat exchanger and a thermoelectric heating, ventilation and air conditioning system (HVAC) configured to provide a cooled fluid or air stream and a heated fluid or air stream. The thermoelectric heat exchanger may include a plurality thermoelectric devices (TEDs), also known as thermoelectric coolers (TECs) or Peltier coolers, in thermal communication. The thermoelectric devices may be arranged in a three dimensional array to provide compact packaging for the thermoelectric heat exchanger assembly. The thermoelectric heat exchanger may be configured to transfer thermal energy between a first thermoelectric device and a second thermoelectric device via evaporation and condensation of a working fluid or refrigerant contained within the thermoelectric heat exchanger.

Abstract: A plate-type heat exchanger having a first heat exchanger portion configured to receive a refrigerant flow and a hot side coolant flow having a lower temperature than the refrigerant flow, a second heat exchanger portion configured to receive the refrigerant flow exiting from the first heat exchanger portion and a cold side coolant flow having a higher temperature than the refrigerant flow exiting from the first heat exchanger portion, and an internal heat exchanger portion sandwiched between the first heat exchanger portion and the second heat exchanger portion. The refrigerant flow through the plate type heat exchanger is in non-contact thermal communication with the hot side coolant flow and the cold side coolant flow. The cold side coolant flow transfers heat energy to the refrigerant, which in turn transfer that heat energy to the hot side coolant flow.

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: A refrigerant leak detection system is provided for a motor vehicle, in which the system includes a heating, ventilating, and air conditioning (HVAC) module having a refrigerant sensor assembly adapted to be fixed within the drain hole of the sump. The refrigerant sensor assembly includes an elongated sensor element extending into the sump, a flange portion having apertures that allows the condensate to drain from sump, a collar portion with self-tapping threads.

Abstract: A heating, ventilation, and air conditioning (HVAC) system configured for use in a vehicle to provide a perceived comfortable thermal environment to an occupant seated in a rear portion of a vehicle cabin. A heat exchanger provides a first airstream characterized as having a first temperature to an air moving device configured to generate a second airstream characterized as having a second temperature. The second airstream comprises a mixture of the first airstream and cabin air drawn from the rear portion of the vehicle cabin. The air moving device may be disposed in the rear portion of the vehicle. The HVAC system further includes a nozzle that may be configured to direct the second airstream toward an occupant in the rear portion of the vehicle cabin to provide spot conditioning.

Abstract: A system and a method of controlling a ventilation or HVAC system that is configured to provide an air stream having a comfortable contact velocity to an occupant seated in a vehicle cabin. The system includes a sensor to determine the distance from a discharge nozzle to the vehicle occupant and a controller to control the exit velocity and/or an effective diameter of the nozzle. The sensor may use ultrasonic, infrared, LIDAR, or RADAR technology to determine distance. The system may determine the distance from the nozzle to the occupant based on a seat location determined by a seat location sensor. The seat location sensor may be common to an inflatable restraint (air bag) system.

Abstract: The disclosure relates to a unitary heat pump air conditioner (Unitary HPAC) that includes a refrigerant loop having a condenser, a refrigerant expansion device, and an evaporator hydraulically connected in series. An electrically driven compressor is provided to circulate a two-phase refrigerant through the refrigerant loop to transfer heat from the evaporator to the condenser. The unitary HPAC also includes a cold side chiller configured to hydraulically connect to a cold side coolant loop and is in thermal communication with the evaporator. The unitary HPAC further includes a hot side chiller configured to hydraulically connect to a hot side coolant loop and is in thermal communication with the condenser. The refrigerant loop transfer heat from the cold side chiller to the hot side chiller, thereby cooling the cold side coolant loop and heating the hot side coolant loop. The components of the unitary HPAC are mounted on a common platform.

Abstract: A method of controlling an air conditioning compressor in a heating ventilation and air conditioning system having a evaporator including a phase change material is presented. The method includes the steps of measuring an evaporator output air temperature, determining a state of charge value by calculating a difference between an estimated refrigerant temperature based on the evaporator output air temperature and a phase change material freeze temperature and integrating this difference over time and operating the air conditioning compressor to maintain the state of charge value between an upper and lower limit. A method of recovering braking energy in a vehicle containing a heating ventilation and air conditioning system having the evaporator including the phase change material is also presented.

Abstract: A vehicle air conditioner system having, and method of operating, an externally controlled variable displacement compressor and a compressor clutch. If the system is operating during conditions when the operating displacement is low, the efficiency of the system is increased by duty cycling the clutch. Operating an externally controlled variable displacement compressor in this manner can also prevent overcooling by the air conditioner.

Abstract: An air conditioning system including an evaporator having a manifold and a plurality of tubes extending downward in a vertical direction from the manifold. The evaporator defines at least one PCM tank engaging the manifold for storing a phase change material. When operating in a first operating mode, heat is transferred from the phase change material to the refrigerant to freeze and cool the phase change material. When operating in a second operating mode, heat is transferred from the refrigerant to the frozen phase change material to condense the refrigerant. The condensed refrigerant falls downwardly through the tubes and receives heat from a flow of air to cool the air and evaporate the refrigerant. The evaporated refrigerant rises upwardly back to the low pressure of the cold manifold.