Viscous Heater, Refrigerant Compressor and Control

Abstract

An HVAC system for a vehicle may include a refrigerant compressor and viscous heater located adjacent to one another and driven by a through-shaft. They may be variable capacity, with the capacities controlled by an HVAC controller to provide the desired HVAC output while staying within a maximum torque limit for an accessory drive.

1 . A refrigerant compressor and viscous heater assembly for use with a vehicle HVAC system, the refrigerant compressor and viscous heater assembly comprising:
 a through-shaft;   a drive mechanism rotationally coupled to the through-shaft to provide a drive torque to the through-shaft;   a refrigerant compressor operatively engaging the through-shaft to be driven by the through-shaft; and   a viscous heater located adjacent to the refrigerant compressor and operatively engaging the through-shaft to be driven by the through-shaft.   
     
     
         2 . The assembly of  claim 1  wherein the refrigerant compressor and the viscous heater are contained within an integrated compressor/viscous heater housing. 
     
     
         3 . The assembly of  claim 1  wherein the drive mechanism is a pulley rotationally fixed to the through-shaft and an accessory drive belt operatively engaging the pulley to provide a drive torque thereto. 
     
     
         4 . The assembly of  claim 1  wherein the refrigerant compressor is a variable capacity compressor and is adapted to have a refrigerant compressing capacity varied by an HVAC controller. 
     
     
         5 . The assembly of  claim 4  wherein the viscous heater is a variable heat output viscous heater and is adapted to have a variable heat output varied by the HVAC controller. 
     
     
         6 . The assembly of  claim 1  wherein the viscous heater is a variable heat output viscous heater and is adapted to have a variable heat output varied by an HVAC controller. 
     
     
         7 . The assembly of  claim 1  wherein the viscous heater is a pump adapted to pump coolant therethrough. 
     
     
         8 . The assembly of  claim 1  wherein the viscous heater and the refrigerant compressor are axially aligned. 
     
     
         9 . An HVAC system for use with a vehicle comprising:
 a refrigerant circuit including a refrigerant compressor;   a coolant circuit including a viscous heater located adjacent to the refrigerant compressor;   a through-shaft operatively engaging and providing a drive torque to the refrigerant compressor and the viscous heater;   a drive mechanism rotationally coupled to the through-shaft to provide the drive torque to the through-shaft; and   an HVAC controller for controlling the refrigerant compressor and the viscous heater.   
     
     
         10 . The HVAC system of  claim 9  wherein the viscous heater is a variable heat output viscous heater and is adapted to have a variable heat output varied by the HVAC controller. 
     
     
         11 . The HVAC system of  claim 9  wherein the refrigerant compressor is a variable capacity compressor and is adapted to have a refrigerant compressing capacity varied by the HVAC controller. 
     
     
         12 . The HVAC system of  claim 11  wherein the viscous heater is a variable heat output viscous heater and is adapted to have a variable heat output varied by the HVAC controller. 
     
     
         13 . The HVAC system of  claim 9  wherein the refrigerant compressor and the viscous heater are contained within an integrated compressor/viscous heater housing. 
     
     
         14 . The HVAC system of  claim 9  wherein the viscous heater is a pump adapted to pump coolant through the coolant circuit. 
     
     
         15 . The HVAC system of  claim 9  wherein the HVAC controller is adapted to receive a coolant temperature input and base a heat output control of the viscous heater at least in part on the coolant temperature. 
     
     
         16 . A method of operating an HVAC system of a vehicle, the method comprising the steps of:
 (a) driving a refrigerant compressor and a viscous heater, located adjacent to the refrigerant compressor, with a through-shaft;   (b) selecting an HVAC mode of operation;   (c) adjusting a refrigerant compressing capacity of the refrigerant compressor based at least partially on the selected HVAC mode of operation; and   (d) adjusting a heat output capacity of the viscous heater based at least partially on the selected HVAC mode of operation.   
     
     
         17 . The method of  claim 16  further including the step of (e) rotationally driving the through-shaft with a pulley driven by a belt. 
     
     
         18 . The method of  claim 16  wherein step (d) is further defined by adjusting the heat output capacity based at least partially on at least one of an engine coolant temperature and a coolant temperature at an inlet to the viscous heater. 
     
     
         19 . The method of  claim 16  wherein steps (c) and (d) are further defined by adjusting the refrigerant compressing capacity and the heat output capacity at least partially on at least one of an outside air temperature and a temperature set point. 
     
     
         20 . The method of  claim 16  further including a step of (e) monitoring an accessory drive torque load and adjusting at least one of the refrigerant compressing capacity and the heat output capacity to maintain the accessory drive torque load below a predetermined maximum accessory drive torque load.