Reversible mode vehicle heating and cooling system for vehicles and method therefor

Abstract

A reversible mode heating and cooling system for an interior space of a vehicle having an Auxiliary Power Unit (APU) employs a heat pump arrangement, wherein a refrigerant compressor is driven by APU's diesel engine through pulley and belt arrangement. An air duct is provided to communicate engine exhaust air to an external heat exchanger during a heating mode. Openings and dampers are provided in the air duct to direct engine exhaust air flow to atmosphere and introduce ambient air into the external heat exchanger during cooling mode. Exhausted air from the external heat exchanger may be re-circulated back to the air inlet side of the engine. Provisions are also provided for operating the refrigerant compressor from the electrical power grid.

1 . In combination with a vehicle including an auxiliary power system having an air cooled diesel engine and an engine fan connected to a shaft thereof and further including a heat exchange unit mounted within an interior space of said vehicle and arranged in heat exchange relationship with air in said interior space for condensing a refrigerant and heating said air during the heating mode and evaporating said refrigerant and cooling said air during the cooling mode, a reversible mode heating and cooling system for heating and cooling an interior space comprising:
 (a) a compressor for compressing vaporous refrigerant, said compressor arranged in refrigerant communication with said interior heat exchange unit;   (b) a power transmission means for connecting said compressor to a rotating shaft of the diesel engine and for operating said compressor thereby;   (c) a heat exchanger mounted externally in heat exchange relationship with each of the ambient air and exhaust air from the engine, said heat exchanger further arranged in refrigerant communication with said compressor for evaporating refrigerant during the heating mode and condensing said refrigerant during the cooling mode;   (d) a blower unit in air communication relationship with said heat exchanger;   (e) a refrigerant expansion valve operatively disposed intermediate said heat exchanger and said heat exchange unit; and   (f) a refrigerant flow reversing valve operable for providing heating and cooling modes from said system by a refrigerant flow direction selection.   
   
   
       2 . The heating and cooling system, according to  claim 1 , wherein said power transmission means includes a belt member and a pair of pulleys, one of said pair of pulleys is secured to the engine shaft for rotation therewith and another one of said pair of pulleys is rotatably secured to said compressor. 
   
   
       3 . The heating and cooling system, according to  claim 1 , wherein said system includes an air duct means arranged in air communication with each of said engine fan and said heat exchanger for supplying engine's exhaust air thereto. 
   
   
       4 . The heating and cooling system, according to  claim 3 , wherein said system includes a pair of openings formed in said air duct means, wherein one of said pair of openings is employed for directing a flow of said exhaust air from said engine to atmosphere and wherein another one of said pair of openings is employed for enabling flow of ambient air into said first heat exchanger. 
   
   
       5 . The heating and cooling system, according to  claim 1 , wherein said system includes:
 (a) an air duct means arranged in air communication with each of said engine fan and said heat exchanger for supplying engine's exhaust air thereto;   (b) a first opening formed in said air duct means for directing a flow of said exhaust air from said engine to atmosphere;   (c) a first damper operatively connected to said air duct means and movable for covering said first opening during heating mode and uncovering said first opening during said cooling mode;   (d) a second openings formed in said air duct means for enabling flow of ambient air into said first heat exchanger;   (e) a second damper operatively connected to said air duct means and movable for selectively covering said second opening during heating mode and uncovering said second opening during cooling mode; and   (f) means operatively connected to each of said first and second dampers and operable for moving said each of said first and second dampers to cover and uncover said first and second openings respectively.   
   
   
       6 . The heating and cooling system, according to  claim 5 , said moving means includes a manually operable linkage. 
   
   
       7 . The heating and cooling system, according to  claim 5 , said moving means includes a pair of electrically operable motors each of said pair of motors connected to one of said first and second dampers. 
   
   
       8 . The heating and cooling system, according to  claim 7 , wherein said system includes one of a generator and alternator for supplying power to said each motor and said refrigerant flow reversing valve. 
   
   
       9 . The heating and cooling system, according to  claim 1 , wherein said system includes a second air duct means for re-circulating air exhausted by said blower unit to the diesel engine during said heating mode. 
   
   
       10 . The heating and cooling system, according to  claim 9 , wherein said system further includes a damper rotatably mounted within said second duct means and an electric motor coupled to a shaft of said damper for preventing recirculation of said air exhausted by said blower unit to the diesel engine during said cooling mode. 
   
   
       11 . The heating and cooling system, according to  claim 1 , wherein said system includes means for operating at least said refrigerant compressor from electrical power grid. 
   
   
       12 . The heating and cooling system, according to  claim 11 , wherein said means includes:
 (a) a first clutch secured to the shaft of the engine for rotation therewith;   (b) an electric motor connectable to said electrical power grid;   (c) a second clutch secured to an output shaft of said electric motor for rotation therewith;   (d) a pulley rotatably mounted on said refrigerant compressor; and   (e) a belt member seated on each of said first and second clutches and said pulley, whereby said refrigerant compressor is operable by way of said first clutch during operation of the engine and is operable by way of said second clutch during operation of said electric motor from the electric power grid.   
   
   
       13 . In combination with a vehicle including an auxiliary power system having an air cooled diesel engine and an engine fan connected to a shaft thereof and further including a heat exchange unit mounted within an interior space of said vehicle and arranged in heat exchange relationship with air in said interior space for condensing a refrigerant and heating said air during the heating mode and evaporating said refrigerant and cooling said air during the cooling mode, a reversible mode heating and cooling system for heating and cooling an interior space comprising:
 (a) a compressor for compressing vaporous refrigerant, said compressor arranged in refrigerant communication with said interior heat exchange unit;   (b) a heat exchanger mounted externally in heat exchange relationship with each of the ambient air and exhaust air from the engine, said heat exchanger further arranged in refrigerant communication with said compressor for evaporating refrigerant during the heating mode and condensing said refrigerant during the cooling mode;   (c) an air duct means in air communication with each of said engine fan and said heat exchanger for supplying air thereto;   (d) a blower unit in air communication relationship with said heat exchanger;   (e) a refrigerant expansion valve operatively disposed intermediate said heat exchanger and said heat exchange unit; and   (f) a refrigerant flow reversing valve operable for providing heating and cooling modes from said system by a refrigerant flow direction selection.   
   
   
       14 . In combination with a vehicle including an auxiliary power system having an air cooled diesel engine and an engine fan connected to a shaft thereof and further including a heat exchange unit mounted within an interior space of said vehicle and arranged in heat exchange relationship with air in said interior space for condensing a refrigerant and heating said air during the heating mode and evaporating said refrigerant and cooling said air during the cooling mode, a reversible mode heating and cooling system for heating and cooling an interior space comprising:
 (a) a compressor for compressing vaporous refrigerant;   (b) a power transmission means for connecting said compressor to a rotating shaft of the diesel engine and for operating said compressor thereby;   (c) a first heat exchanger mounted externally in heat exchange relationship with exhaust air from the engine, said first heat exchanger further arranged in refrigerant communication with said compressor for evaporating refrigerant during the heating mode;   (d) a second heat exchanger mounted externally in heat exchange relationship with the ambient air, said second heat exchanger further arranged in refrigerant communication with said compressor for condensing said refrigerant during the cooling mode;   (e) a blower unit in air communication relationship with said second heat exchanger;   (f) a first refrigerant expansion valve operatively disposed intermediate said first heat exchanger and said internal heat exchange unit;   (g) a second refrigerant expansion valve operatively disposed intermediate said second heat exchanger and said internal heat exchange unit;   (h) a refrigerant flow reversing valve operable for providing heating and cooling modes from said system by a refrigerant flow direction selection;   (i) a first check valve operatively disposed intermediate said refrigerant flow reversing valve and said first heat exchanger for preventing refrigerant flow thereto during the cooling mode; and   (j) a second check valve operatively disposed intermediate said second heat exchanger and said internal heat exchange unit for preventing refrigerant flow to said second heat exchanger during the heating mode.   
   
   
       15 . The heating and cooling system, according to  claim 14 , wherein said system includes said internal heat exchange unit. 
   
   
       16 . A method for at least one of heating and cooling an interior space of a vehicle including an auxiliary power unit having an engine and an engine fan connected to a shaft thereof, said method comprising the steps of:
 (a) providing a heat pump apparatus having a refrigerant compressor;   (b) connecting, with a power transmission means, said refrigerant compressor to said shaft of said engine; and   (c) selectively cooling and heating, with said heat pump apparatus, said interior space.   
   
   
       17 . The method, according to  claim 16 , wherein said heating and cooling step includes the step of connecting an external heat exchanger of said heat pump apparatus in air communication means with an air exhausted from said engine. 
   
   
       18 . The method, according to  claim 17 , wherein said method includes the additional step of controlling flow of each of the ambient air and engine exhaust air to an external heat exchanger of said heat pump apparatus.