Compact hvac system for a motor vehicle

Abstract

The invention relates to a compact vehicle HVAC system including an evaporator unit, a condenser unit, and a component unit, as well as a refrigerant circuit. The evaporator unit and the condenser unit each are provided with air-passed heat exchangers and a fan in a casing. Further circuit components are displaced within the component unit. The casings of the evaporator unit, the condenser unit, and the component unit advantageously establish a connected compact casing arrangement. The heat exchangers are displaced within the compact casing arrangement. The refrigerant circuit is established for a combined refrigeration plant and heat pump operation as well as an afterheating operation, whereby in the afterheating operational mode the heating power of the afterheater established as condenser/gas cooler and the cooling power of the evaporator are controllable independently of each other.

1 . A vehicle HVAC system comprising:
 an evaporator unit including two air-passed heat exchangers and a fan disposed in a casing;   a condenser unit including an air-passed heat exchanger and a fan disposed in a casing;   a component unit housing a plurality of circuit components; and   a refrigerant circuit, wherein the casings of the evaporator unit, the condenser unit, and the component unit establish an integrated, compact casing arrangement in which the refrigerant circuit is disposed, wherein the heat exchangers of the evaporator unit and the condenser unit are disposed within the casing arrangement and are in fluid communication with the refrigerant circuit.   
     
     
         2 . The vehicle HVAC system according to  claim 1 , wherein the evaporator unit, the condenser unit, and the component unit are single units, joined to form the casing arrangement. 
     
     
         3 . The vehicle HVAC system according to  claim 1 , wherein the evaporator unit and the condenser unit each include a flow channel for air, wherein each of the flow channels is supplied with at least one of fresh air from the environment, recirculated air from the passenger compartment, and a mixture of fresh air and recirculated air from the passenger compartment. 
     
     
         4 . The vehicle HVAC system according to  claim 3 , wherein a compressor of the refrigerant circuit is disposed in the flow channel of the condenser unit. 
     
     
         5 . The vehicle HVAC system according to  claim 3 , wherein the flow channels of the evaporator unit and the condenser unit are positioned such that a direction of flow of air leaving the evaporator unit and a direction of a flow of air leaving the condenser unit are oriented parallel to each other. 
     
     
         6 . The vehicle HVAC system according to  claim 3 , wherein the flow channels of the evaporator unit and the condenser unit are positioned such that a direction of flow of air leaving the evaporator unit and a direction of a flow of air leaving the condenser unit are oriented opposite to each other along a common axis. 
     
     
         7 . The vehicle HVAC system according to  claim 1 , wherein the fans of the evaporator unit and the condenser unit are respectively disposed laterally next to the flow channels of the evaporator unit and the condenser unit. 
     
     
         8 . The vehicle HVAC system according to  claim 1 , wherein the fans of the evaporator unit and the condenser unit are disposed at opposite sides of the casing arrangement. 
     
     
         9 . The vehicle HVAC system according to  claim 1 , wherein the refrigerant circuit includes an electrically driven compressor. 
     
     
         10 . A vehicle HVAC system having a refrigerant circuit comprising:
 a primary circuit with a compressor, a heat exchanger passable bidirectionally for heat transfer between a refrigerant and the environment, a first expansion member with two flow paths passable by the refrigerant in opposite directions, and a heat exchanger passable bidirectionally for a heat supply from air to be conditioned for a passenger compartment to the refrigerant;   a secondary branch including a first flow path and a second flow path, the first flow path extending from a tap positioned between the compressor and the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment to a tap positioned between the heat exchanger passable bidirectionally for the heat supply from the air to be conditioned for the passenger compartment to the refrigerant and the compressor, the first flow path provided with a heat exchanger for transferring heat from the refrigerant to the air to be conditioned for the passenger compartment and a second expansion member disposed downstream of the heat exchanger for transferring heat from the refrigerant to the air to be conditioned for the passenger compartment, the second flow path extending from a tap positioned between the compressor and the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment to a tap positioned between the heat exchanger passable bidirectionally for the heat supply from the air to be conditioned for the passenger compartment to the refrigerant and the compressor; and   a valve disposed between the tap positioned between the compressor and the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment of the first flow path and the tap positioned between the compressor and the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment of the second flow path, wherein the HVAC system is operable in a combined refrigeration plant mode and a heat pump mode, as well as an afterheating operation mode.   
     
     
         11 . The vehicle HVAC system according to  claim 10 , wherein the valve is a shut-off valve. 
     
     
         12 . The vehicle HVAC system according to  claim 10 , wherein the heat exchanger passable bidirectionally for the heat supply from air to be conditioned for the passenger compartment to the refrigerant is an evaporator. 
     
     
         13 . The vehicle HVAC system according to  claim 10 , wherein the heat exchanger for transferring heat from the refrigerant to the air to be conditioned for the passenger compartment is a condenser/gas cooler. 
     
     
         14 . The vehicle HVAC system according to  claim 10 , wherein the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment, dependent on an operational mode of the vehicle HVAC system is a condenser/gas cooler or an evaporator. 
     
     
         15 . The vehicle HVAC system according to  claim 10 , further comprising an accumulator with an internal heat exchanger disposed in the primary circuit, wherein the accumulator on a low pressure side is positioned in direction of a flow of the refrigerant between the tap positioned between the heat exchanger passable bidirectionally for the heat supply from the air to be conditioned for the passenger compartment to the refrigerant and the compressor and the internal heat exchanger. 
     
     
         16 . The vehicle HVAC system according to  claim 15 , wherein the tap positioned between the heat exchanger passable bidirectionally for the heat supply from the air to be conditioned for the passenger compartment to the refrigerant and the compressor is a passive three-way valve, wherein a direction of flow of the refrigerant is passively switchable. 
     
     
         17 . The vehicle HVAC system according to  claim 16 , wherein the passive three-way valve is established such that a side where a higher pressure is applied is closed by a pressure differential present at the passive three-way valve. 
     
     
         18 . The vehicle HVAC system according to  claim 10 , further comprising an additional heat exchanger with an expansion member connected upstream thereof disposed in the primary circuit, whereby the additional heat exchanger is disposed in parallel to the heat exchanger passable bidirectionally for the heat supply from air to be conditioned for the passenger compartment to the refrigerant. 
     
     
         19 . The vehicle HVAC system according to  claim 10 , further comprising a fan providing a flow of air through the heat exchanger passable bidirectionally for heat transfer between the refrigerant and the environment. 
     
     
         20 . The vehicle HVAC system according to  claim 10 , further comprising a fan providing a flow of air through the heat exchanger for transferring heat from the refrigerant to the air to be conditioned for the passenger compartment.