Vehicle with air conditioning system

Abstract

A vehicle includes an air conditioning system for conditioning intake air flowing into a vehicle interior. The air conditioning system has a primary heat exchanger in thermal communication with a drive unit via a coolant circuit, a compressor, and a secondary heat exchanger which is disposed jointly with the compressor in a refrigerant circuit. The secondary heat exchanger operates as a condenser in a heating mode of the air conditioning system and jointly with the primary heat exchanger gives off heat to the intake air. A control device controls operation of the refrigerant circuit in response to an input by a user. The control device includes an evaluation unit to carry out a comparison between a desired heat supply commensurate with the input by the user and a determined actual heat supply, and generates an output signal for operating the compressor in response to the comparison.

1 . A vehicle, comprising an air conditioning system for conditioning intake air flowing into a vehicle interior, said air conditioning system comprising:
 a primary heat exchanger in thermal communication with a drive unit via a coolant circuit,   a compressor,   a secondary heat exchanger disposed jointly with the compressor in a refrigerant circuit, said secondary heat exchanger operating as a condenser in a heating mode of the air conditioning system and jointly with the primary heat exchanger giving off heat to the intake air, and   a control device controlling operation of the refrigerant circuit in response to an input by a user, said control device including an evaluation unit to carry out a comparison between a desired heat supply commensurate with the input by the user and a determined actual heat supply, and generating an output signal for operating the compressor in response to the comparison.   
     
     
         2 . The vehicle of  claim 1 , wherein the compressor has a maximum output that can be set by the control device and is at a level to allow the secondary heat exchanger to generate a heat output which exceeds a heat output of a conventional PTC (Positive Temperature Coefficient) heating element. 
     
     
         3 . The vehicle of  claim 1 , wherein the actual heat supply is determined only on the basis of a parameter of the intake air. 
     
     
         4 . The vehicle of  claim 1 , wherein the primary and secondary heat exchangers form a heating assembly, further comprising temperature sensors constructed to ascertain an air entry temperature and an air exit temperature of the heating assembly, respectively, to thereby determine the actual heat supply. 
     
     
         5 . The vehicle of  claim 3 , further comprising a determination unit operatively connected to the evaluation unit and adapted to determine an air mass flow of the intake air for ascertaining the actual heat supply. 
     
     
         6 . The vehicle of  claim 5 , wherein the primary and secondary heat exchangers form a heating assembly, and further comprising a flow flap and a fan for transport of the air mass flow of the intake air, said flow flap and said fan being placed upstream of the heating assembly to allow adjustment of a flow cross section and flow rate of the intake air. 
     
     
         7 . The vehicle of  claim 6 , wherein the determination unit is constructed to determine the air mass flow as a function of an electric fan output of the fan or a fan parameter in correlation with the electric fan output, and a flap position of the flow flap. 
     
     
         8 . The vehicle of  claim 1 , wherein the primary and secondary heat exchangers form a heating assembly, said air conditioning system including an air conditioner arranged upstream of the heating assembly and including an evaporator which is disposed jointly with the secondary heat exchanger in the refrigerant circuit, said evaporator being idle in the heating mode and adapted to absorb heat from the intake air in a cooling mode of the air conditioning system while the secondary heat exchanger is idle. 
     
     
         9 . The vehicle of  claim 8 , wherein the air conditioning system has a temperature sensor operably connected to the evaporator for ascertaining an evaporation temperature in the cooling mode, said temperature sensor adapted to ascertain an air entry temperature of the heating assembly in the heating mode. 
     
     
         10 . The vehicle of  claim 9 , wherein the temperature sensor is arranged on an outside of the evaporator. 
     
     
         11 . A method of operating an air conditioning system of a vehicle, comprising:
 determining an actual heat supply into a vehicle interior;   comparing the determined actual heat supply with a desired heat supply commensurate with a user's input;   generating an output signal as a function of the comparison; and   operating a compressor in response to the output signal and causing a secondary heat exchanger to operate as a condenser in a heating mode of the air conditioning system so as to give off heat to the intake air flowing into the vehicle interior air jointly with a primary heat exchanger, when the actual heat supply is below the desired heat supply.   
     
     
         12 . The method of  claim 11 , wherein the compressor has a maximum output that can be set by the control device and is at a level to allow the secondary heat exchanger to generate a heat output which exceeds a heat output of a conventional PTC (Positive Temperature Coefficient) heating element. 
     
     
         13 . The method of  claim 11 , wherein the actual heat supply is determined only on the basis of a parameter of the intake air. 
     
     
         14 . The method of  claim 11 , wherein the determining step includes detecting an air entry temperature and an air exit temperature of a heating assembly comprised of the primary and secondary heat exchangers. 
     
     
         15 . The method of  claim 13 , wherein the parameter is an air mass flow of the intake air. 
     
     
         16 . The method of  claim 15 , further comprising controlling a transport of the air mass flow of the intake air by adjusting a flow cross section and a flow rate of the intake air. 
     
     
         17 . The method of  claim 16 , wherein the air mass flow is determined as a function of an electric fan output of a fan or a fan parameter in correlation with the electric fan output, and a flap position of a flow flap upstream of a heating assembly comprised of the primary and secondary heat exchangers. 
     
     
         18 . The method of  claim 11 , further comprising operating an evaporator to absorb heat from the intake air in a cooling mode of the air conditioning system while idling the secondary heat exchanger. 
     
     
         19 . The method of  claim 11 , further comprising idling the evaporator in the heating mode of the air conditioning system. 
     
     
         20 . The method of  claim 18 , further comprising ascertaining an evaporation temperature in the cooling mode by a temperature sensor, and ascertaining in the heating mode an air entry temperature of a heating assembly comprised of the primary and secondary heat exchangers, using the temperature sensor.