Thermal powered hydronic chiller using low grade heat

Abstract

This invention employs an arrangement of flat plate heat exchangers and a pump that function as a thermal powered hydronic ammonia absorption chiller. Chilling is achieved by bubbling ammonia gas through a liquid refrigerant causing a reduction of the partial pressure of the refrigerant and evaporation with the absorption of heat. The refrigerant and working fluids can be selected to have a broad range of operating pressures. If the refrigerant and working fluid are selected so that the atmospheric boiling point is the about the same as the highest operating ambient temperature, the chiller can operate with low, or even no internal pressure. The low operating pressures allow the use of light weight materials, easy fabrication, low cost and safety. This chiller is especially suited for using solar heated water, cooling water from internal combustion engines or any source of hot water. The chiller is easily scalable to any size and will find wide application for comfort air conditioning or food storage.

1 . A thermal powered hydronic chiller comprising:
 a. generator ( 15 ) consisting of a flat plate heat exchanger in which ammonia gas ( 26 ) is generated by transferring the heat from a hot fluid to an ammonia strong solution ( 23 ),   b. a hot economizer ( 14 ) comprised of a flat plate heat exchanger, disposed at a level below said generator, in which the heat from the ammonia weak solution ( 24 ) exiting said generator is transferred to said strong solution ( 26 ),   c. an evaporator ( 11 ) consisting of a flat plate heat exchanger, in which said gas ( 26 ) is bubbled through a refrigerant my means of   d a linear bubbler ( 31 ) consisting of a horizontal tube with a plurality of holes along the top of its length causing said gas to be distributed among the many plates of said evaporator ( 11 ), causing said refrigerant ( 25 ) to evaporate at reduced temperature and transfer heat to a fluid to be chilled,   e. a cold economizer ( 12 ) consisting of a flat plate heat exchanger, in which said refrigerant ( 25 ) entering said evaporator ( 11 ) transfers heat to the cold gaseous mixture ( 27 ) of ammonia and refrigerant ( 25 ) exiting said evaporator ( 11 ),   f. an absorber ( 13 ) consisting of a flat plate heat exchanger in which said weak solution ( 24 ) and said gaseous mixture ( 27 ) are mixed and introduced into the top of said absorber ( 13 ), by means of   g. a linear aspirator ( 32 ) comprised of a horizontal tube with a plurality of holes along its length in which said gaseous mixture ( 27 ) and said strong solution ( 23 ) escape at different velocities causing intimate mixing and distribution among the plates of said absorber ( 13 ), transferring heat to a cooling fluid, causing said strong solution ( 23 ) and said refrigerant ( 25 ) to be regenerated as separate liquid phases and drain out the bottom of said absorber ( 13 ) and into   f. a separator ( 23 ) consisting of a container of sufficient horizontal area to cause said refrigerant ( 25 ) and said ammonia strong solution ( 23 ) to separate into two distinct phases, disposed at a level that is below the evaporator ( 11 ), so that only refrigerant ( 25 ) will flow to said cold economizer ( 12 ) and said strong solution ( 23 ) will flow to   g. a pump ( 19 ) disposed at the bottom of the separator ( 18 ) so that it only draws strong solution ( 23 ) and discharges said strong solution to the inlet of said hot economizer.   
     
     
         2 . The thermal powered hydronic chiller in  claim 1  in which
 a. a gas cooler ( 16 ) consisting of a flat plate heat exchanger is disposed below said hot economizer, receiving gas flowing in a downward direction and transfers heat from said gas to said strong solution ( 23 ) prior to discharging of said strong solution to said hot economizer,   b. a gas chiller ( 17 ) consisting of a flat plate heat exchanger disposed at a level below said gas cooler, receiving gas from said gas cooler flowing in a downward direction, transferring heat to a portion of the cold said gaseous mixture from the evaporator, and collecting condensed water vapors for discharge to said separator prior to discharging said gas to said evaporator.   
     
     
         3 . The thermal powered hydronic chiller in  claims 1  and  2  in which, said generator, hot economizer, gas cooler gas chiller cold economizer and evaporator are assembled as a contiguous series of heat exchangers in which the discharge of one heat exchanger is mated directly to the inlet of the next heat exchanger. 
     
     
         4 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is an aqueous fluid supplied by a solar collector. 
     
     
         5 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is the aqueous cooling fluid of an internal combustion engine. 
     
     
         6 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is the cooling fluid of an electric motor. 
     
     
         7 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is derived from water used to scrub flu gas. 
     
     
         8 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is flu gas. 
     
     
         9 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is heated by the engine exhaust gas of an internal combustion engine. 
     
     
         10 . The thermal powered hydronic chiller in  claims 1 ,  2  and  3  in which said hot fluid is internal combustion engine exhaust gas.