Systems and methods for compressing, storing, and expanding refrigerant in order to supply low-cost air conditioning

Abstract

An air conditioning system includes a compression unit; a plurality of high pressure condensing tanks; an expander for releasing the compressed refrigerant from the high pressure tanks while expanding the compressed refrigerant; an evaporator; low-pressure storage tanks for collecting discharged vapor from the evaporator; and a conduit for conveying the refrigerant vapor from the low-pressure storage tanks to an intake of the compression unit. The compression unit may include pairs of liquid-gas pistons, each pair having first and second cylinders having substantially equal volumes, a pressure equalizing valve arranged between the first and second cylinders of each pair, and a liquid pump. Pressurizing of gas through pumping of liquid through each respective pair of liquid gas pistons is performed with a constant time shift. An expander may capture work of expanding refrigerant for purposes of pumping of liquid in the compression unit.

1 . An air conditioning system, comprising:
 a compression unit configured to compress a gaseous refrigerant;   a plurality of high pressure condensing tanks connected to an outlet of the compression unit and configured to store the compressed refrigerant;   an expander or expansion valve in fluid communication with an outlet of the plurality of high pressure condensing tanks, for releasing the compressed refrigerant from the plurality of high pressure condensing tanks while expanding a volume of the compressed refrigerant;   an evaporator in fluid communication with an outlet of the expander or expansion valve for causing the refrigerant to absorb heat from a surrounding environment;   a plurality of low-pressure storage tanks for collecting discharged refrigerant vapor from the evaporator; and   a conduit for conveying the refrigerant vapor from the plurality of low-pressure storage tanks to an intake of the compression unit.   
     
     
         2 . The air conditioning system of  claim 1 , further comprising one or more of the following:
 a recuperator arranged between the plurality of high pressure condensing tanks and the expander or expansion valve, said recuperator configured to cool incoming condensed refrigerant with outgoing expanded refrigerant;   a first heat exchange unit configured to receive heat from the refrigerant during compression thereof to thereby heat an external supply of water;   a second heat exchange unit configured to be cooled by the refrigerant during expansion thereof to thereby cool an external supply of water.   
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The air conditioning system of  claim 1 , wherein the refrigerant is carbon dioxide and being liquid in the plurality of high-pressure condensing tanks and is gaseous in the plurality of low pressure storage tanks. 
     
     
         6 . (canceled) 
     
     
         7 . The air conditioning system of  claim 5 , wherein the carbon dioxide is a supercritical plasma in the plurality of high-pressure condensing tanks and is gaseous in the plurality of low-pressure storage tanks. 
     
     
         8 . A compression unit for a cooling system, comprising:
 at least two pairs of liquid-gas pistons, wherein each pair of liquid gas pistons comprises first and second cylinders having substantially equal volumes, and a combined volume of liquid substantially equivalent to a volume of one of the liquid-gas pistons;   a pressure equalizing valve arranged between the first and second cylinders of each pair of liquid-gas pistons;   a liquid pump in fluid communication with each of the four liquid-gas pistons;   a gas intake valve for low-pressure gas and a gas outlet valve for high-pressure gas arranged at each liquid-gas piston;   and a series of valves arranged between the liquid pump and the respective liquid-gas pistons, wherein the valves may be alternatively opened and closed such that pressure equalization among each pair of liquid gas pistons, and pressurizing of gas through pumping of liquid through each pair of liquid gas pistons, is performed in a constant time shift.   
     
     
         9 . The compression unit of  claim 8 , wherein the constant time shift corresponds to a time required to equalize between the pressures of the first and second cylinders of a pair of cylinders. 
     
     
         10 . The compression unit of  claim 8 , wherein each pair of liquid gas pistons is configured to compress gas in a series of alternating half-cycles, wherein in a first half cycle gas is compressed within a first cylinder through influx of liquid from the second cylinder, and in the second half-cycle gas is compressed within the second cylinder through influx of liquid from the first cylinder. 
     
     
         11 . The compression unit of  claim 10 , wherein, in each half-cycle, gas is first compressed through pressure equalization between the two liquid-gas pistons in a pair, and then is compressed further through pumping of fluid between the two liquid-gas pistons. 
     
     
         12 . The compression unit of  claim 8 , further comprising:
 a main tank having an inlet for receiving therein a gas at low pressure;   an open liquid tank configured to deliver liquid to the first gas tank and thereby compress the gas within the main tank; and   a valve assembly configured to switch between a first state, in which low-pressure gas passes through the main tank and is pressurized by the liquid-gas pistons, and a second state, in which the low-pressure gas is pressurized within the main tank by liquid from the open liquid tank.   
     
     
         13 . The compression unit of  claim 12 , further comprising a turbine arranged between the open liquid tank and the main tank, and configured to produce electricity from the flow of liquid from the main tank to the open liquid tank. 
     
     
         14 . The compression unit of  claim 8 , wherein an interior volume of each cylinder is comprised of a plurality of cooling tubes connected in parallel to each respective gas intake valve, gas outlet valve, and the liquid pump, each cooling tube including a plurality of cooling fins, and further comprising a cooling system for providing cooling fluid or water to an exterior of each of the cooling tubes between the cooling fins. 
     
     
         15 . (canceled) 
     
     
         16 . A cooling system comprising the compression unit of  claim 8  and an expander, said
 expander comprising a first cylinder, a U-shaped duct, and a second cylinder connected in series, wherein an outlet of the second cylinder is connected to the fluid pump of the compression unit and to a low-pressure fluid reservoir, and wherein, during expansion of refrigerant, the expanding refrigerant enters the first cylinder and displaces fluid through the duct and second cylinder to the fluid pump, and, wherein, following expansion of refrigerant, liquid from the low-pressure fluid reservoir enters the second cylinder to thereby evacuate expanded refrigerant from the expander into an evaporator and refill the expander with fluid. 
 
     
     
         17 . A cooling system comprising the compression unit of  claim 8 , a plurality of high pressure condensing tanks connected to an outlet of the compression unit and configured to store the compressed refrigerant; an expander or expansion valve in fluid communication with an outlet of the plurality of high pressure condensing tanks, for releasing the compressed refrigerant from the plurality of high pressure condensing tanks while expanding a volume of the compressed refrigerant; an evaporator in fluid communication with an outlet of the expander or expansion valve for causing the refrigerant to absorb heat from a surrounding environment; a plurality of low-pressure storage tanks for collecting discharged refrigerant vapor from the evaporator; and a conduit for conveying the refrigerant vapor from the plurality of low-pressure storage tanks to an intake of the compression unit. 
     
     
         18 . The cooling system of  claim 17 , wherein the expander or expansion valve is the expander of  claim 16 . 
     
     
         19 . An expander, comprising:
 a first cylinder, a U-shaped duct, and a second cylinder connected in series,   wherein the first cylinder is connected to a source of compressed refrigerant and an evaporator;   wherein the second cylinder is connected to a fluid pump and to a low-pressure fluid reservoir; and   wherein, during expansion of refrigerant, compressed refrigerant enters the first cylinder from the source of compressed refrigerant, and displaces fluid from the first cylinder, duct, and second cylinder to the fluid pump, and, wherein, following expansion of refrigerant, liquid from the low-pressure fluid reservoir enters the second cylinder, duct, and first cylinder to thereby evacuate expanded refrigerant from the expander into the evaporator and refill the expander with fluid.   
     
     
         20 . A method of air conditioning, comprising:
 compressing a gaseous refrigerant;   storing the compressed refrigerant;   expanding a volume of the compressed refrigerant with an expansion valve or expander;   evaporating the refrigerant with an evaporator and thereby causing the refrigerant to absorb heat from a surrounding environment;   collecting discharged refrigerant vapor from the evaporator; and   conveying the discharged refrigerant vapor to an intake of the compressor, and repeating each of the previous steps.   
     
     
         21 . The method of  claim 20 , wherein the storing step comprises storing the compressed refrigerant in a plurality of high-pressure storage tanks, and the collecting step comprises collecting the discharged vapor in a plurality of low-pressure storage tanks. 
     
     
         22 . The method of  claim 20 , further comprising performing one or more of the following steps:
 performing the compressing and storing steps at nighttime, and performing the expanding, evaporating, collecting, and conveying steps during daytime;   performing the compressing step substantially isothermally by supplying a cooling fluid to an exterior of a cylinder used for compression of the carbon dioxide therein;   releasing at least a portion of the compressed refrigerant through a turbine to thereby generate electricity;   performing the expanding, evaporating, and collecting steps without investment of electricity.   
     
     
         23 . The method of  claim 20 , wherein the refrigerant is carbon dioxide, and further comprising performing the compressing step in a subcritical process and/or in a transcritical process. 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 20 , wherein the expanding step comprises using an expander to capture work of the expanding refrigerant to thereby deliver fluid to a fluid pump used to compress the refrigerant during the compressing step. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled)