Daimlerchrysler Corporation

Richard Harris

Barry J Lake

Lance C Tagliapietra

Lawrence Ziehr

David A Barwin

Gerald P Spezia

Bruce T Siekkinen

The invention provides a battery cooling system to cool an electric vehicle battery pack and extend the operating range of an automotive heat pump system. Waste heat from the battery pack is transferred to a secondary coolant system thereby cooling the battery pack. A secondary heat exchanger is coupled between the secondary cooling system and a reversible HVAC system. The secondary heat exchanger transfers the secondary coolant system heat energy to the reversible HVAC system. The heat energy transferred to the reversible HVAC system supplements the existing stored energy thereby extending the heating mode operating range of the HVAC system. The requirement for supplemental electric heating is reduced, further increasing the electric vehicle energy efficiency.

System for cooling electric vehicle batteries

A control system for controlling a reversible HVAC system of a motor vehicle is disclosed. The HVAC system includes an electric compressor for circulating a refrigerant through a heat pump. The speed of the compressor is controlled by a compressor control signal having a variable duty cycle. Inside and outside heat exchangers transfer heat energy between an outside environment and a passenger compartment of the motor vehicle. A refrigerant flow switching device switches the direction of refrigerant flow towards the inside heat exchanger in a heating mode and towards the outside heat exchanger in a cooling mode. A pressure reducing assembly supplies pressure reduced refrigerant to the inside heat exchanger in the cooling mode and to the outside heat exchanger in the heating mode. The pressure reducing assembly includes an electronic expansion valve in which the flow rate is set by an EXV control signal having a variable duty cycle. A controller controls the duty cycle setting of the compressor control signal and the EXV control signal such that a desired quantity of heat is transferred between the outside environment and the passenger compartment.

Controller for reversible air conditioning and heat pump HVAC system for

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Holly, MI, United States of America

Richard Harris