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 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:
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 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:
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 heat exchanger assembly is provided having at least one header, a plurality of spaced apart fluid tubes in hydraulic communication with the header, and a plurality of corrugated fins disposed between the tubes. The corrugated fins include a planar portion having a louver segment defined between a pair of primary slits, in which the louver segment includes an intermediate slit splitting the louver segment into a pair of mini-louvers. The mini-louvers are counter-offset such that one of the mini-louvers is on one side of the planar portion and the other one of the mini-lover is on the other side of the planar portion. The mini-louvers may be pivoted about their respective junctures such that each of the mini-louver segments is oblique relative to the planar portion.
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 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.