Near-isothermal compression, and systems and methods with near-isothermal compression

Abstract

A system can comprise one or more near-isothermal compression (NIC) systems. Each NIC system can have one or more chambers and cooling means. Each NIC system can increase a pressure of a working fluid in the one or more chambers via an incompressible fluid acting as a liquid piston. The cooling means can remove from the working fluid at least some heat generated by the increased pressure. In some embodiments, NIC systems can alternately operate with incompressible fluid flow reversing direction through the one or more chambers based on mode of operation. Alternatively, in some embodiments, a direction of the incompressible fluid flow can be the same regardless of the mode of operation. Alternatively, in some embodiments, a mechanical piston is used to move the incompressible fluid within the chamber to effect compression of the working fluid.

1 . A system comprising:
 at least two near-isothermal compression (NIC) systems, each NIC system comprising one or more chambers and cooling means, each NIC system being constructed to increase a pressure of a working fluid in the one or more chambers via an incompressible fluid acting as a liquid piston, the cooling means being constructed to remove from the working fluid at least some heat generated by the increased pressure;   one or more pumps coupled to the at least two NIC systems and constructed to pump the incompressible fluid to or from the one or more chambers; and   a switching system between the one or more pumps and the at least two NIC systems and constructed to control a flow direction of the incompressible fluid within the respective NIC system,   wherein each NIC system further comprises a staging vessel for the incompressible fluid disposed between the switching system and the corresponding one or more chambers, the staging vessel having a fluid volume greater than a combined fluid volume of the corresponding one or more chambers.   
     
     
         2 . The system of  claim 1 , wherein, for each NIC system:
 the fluid volume of the staging vessel is at least two times the fluid volume of the combined fluid volume of the corresponding one or more chambers.   
     
     
         3 . The system of  claim 1 , wherein, for each NIC system:
 the cooling means is not in thermal communication with the staging vessel.   
     
     
         4 . The system of  claim 1 , further comprising:
 a thermodynamic fluid circuit comprising a first heat exchanger, an expansion device, and a second heat exchanger,   the first heat exchanger being coupled to the at least two NIC systems so as to receive pressurized working fluid from the at least two NIC systems and being constructed to transfer heat from the working fluid flowing through the first heat exchanger,   the expansion device being coupled to the first heat exchanger so as to receive the working fluid from the first heat exchanger and being constructed to reduce a pressure of the working fluid flowing through the expansion device,   the second heat exchanger being coupled to the expansion device so as to receive the working fluid from the expansion device and being constructed to transfer heat to the working fluid flowing through the second heat exchanger, and   the second heat exchanger being further coupled to the at least two NIC systems so as to deliver heated working fluid from the second heat exchanger to the at least two NIC systems.   
     
     
         5 . The system of  claim 4 , wherein:
 the switching system comprises a hydraulic switch;   the expansion device comprises an expansion valve or electronic expansion valve;   the first heat exchanger is constructed to operate as a gas cooler or condenser;   the second heat exchanger is constructed to operate as an evaporator; or   any combination of the above.   
     
     
         6 . The system of  claim 4 , further comprising:
 a pressure vessel constructed to alternately receive pressurized working fluid from one of the NIC systems and to store the pressurized working fluid for dispensing to the first heat exchanger,   wherein, for each NIC system, a fluid volume of the pressure vessel is greater than a combined fluid volume of the one or more chambers.   
     
     
         7 . The system of  claim 1 , wherein the working fluid is carbon dioxide, and the incompressible fluid is oil. 
     
     
         8 . The system of  claim 4 , further comprising:
 a controller operatively coupled to the switching system and comprising one or more processors and one or more non-transitory computer-readable storage media, the computer-readable storage media store computer-readable instructions that, when executed by the one or more processors, cause the one or more processors to:
 control the switching system to have a first state where a first of the at least two NIC systems operates in compression mode, and a second of the at least two NIC systems operates in suction mode; and 
 in response to a predetermined input, control the switching system to have a second state where the first of the at least two NIC systems operates in the suction mode, and the second of the at least two NIC systems operates in the compression mode, 
   wherein, in each NIC system, each of the one or more chambers has opposing first and second ends, the first end being closer than the second end to the respective staging vessel,   in the compression mode, the incompressible fluid flows in a direction from the first end toward the second end, such that the working fluid is compressed within the one or more chambers and flows toward the thermodynamic fluid circuit via the second end, and   in the suction mode, the incompressible fluid flows in an opposite direction from the second end toward the first end, such that working fluid from the thermodynamic fluid circuit flows into the one or more chambers via the second end.   
     
     
         9 - 11 . (canceled) 
     
     
         12 . The system of  claim 1 , wherein each NIC system is constructed such that the working fluid, the incompressible fluid, or both are injected into the one or more chambers. 
     
     
         13 . The system of  claim 4 , further comprising an economizer constructed to cool the pressurized working fluid from the at least two NIC systems. 
     
     
         14 . The system of  claim 4 , further comprising a separator device disposed between the at least two NIC systems and the first heat exchanger, the separator device being constructed to separate the pressurized working fluid from the incompressible fluid en route to the first heat exchanger. 
     
     
         15 . A system comprising:
 at least two near-isothermal compression (NIC) systems, each NIC system comprising one or more chambers and a cooling means, each NIC being constructed to increase a pressure of a working fluid in one or more chambers via an incompressible fluid acting as a liquid piston, the cooling means being constructed to remove from the working fluid at least some heat generated by the increased pressure;   one or more pumps coupled to the at least two NIC systems and constructed to pump the incompressible fluid through the one or more chambers;   a switching system coupled to the at least two NIC systems and constructed to control connections of each NIC system to a fluid circuit; and   a controller operatively coupled to the switching system and comprising one or more processors and one or more non-transitory computer-readable storage media, the computer-readable storage media store computer-readable instructions that, when executed by the one or more processors, cause the one or more processors to:
 control the switching system to have a first state where a first of the at least two NIC systems operates in compression mode, and a second of the at least two NIC systems operates in suction mode; and 
 in response to a predetermined input, control the switching system to have a second state where the first of the at least two NIC systems operates in the suction mode, and the second of the at least two NIC systems operates in the compression mode, wherein, for each NIC system: 
 each of the one or more chambers has opposing first and second ends, and 
 in both the compression mode and the suction mode, a direction of the incompressible fluid flow through the one or more chambers is from the first end to the second end. 
   
     
     
         16 . The system of  claim 15 , further comprising:
 a thermodynamic fluid circuit comprising a first heat exchanger, an expansion device, and a second heat exchanger,   the first heat exchanger being coupled to the at least two NIC systems so as to receive pressurized working fluid from the at least two NIC systems and being constructed to transfer heat from the pressurized working fluid flowing through the first heat exchanger,   the expansion device being coupled to the first heat exchanger so as to receive the working fluid from the first heat exchanger and being constructed to reduce a pressure of the working fluid flowing through the expansion device,   the second heat exchanger being coupled to the expansion device so as to receive the working fluid from the expansion device and being constructed to transfer heat to the working fluid flowing through the second heat exchanger, and   the second heat exchanger being further coupled to the at least two NIC systems so as to deliver heated working fluid from the second heat exchanger to the at least two NIC systems.   
     
     
         17 . (canceled) 
     
     
         18 . The system of  claim 16 , wherein the switching system comprises:
 a first plurality of three-way switches disposed between the second ends of the at least two NIC systems and the thermodynamic fluid circuit; and   a second plurality of three-way switches disposed between the first ends of the at least two NIC systems and the thermodynamic fluid circuit.   
     
     
         19 - 21 . (canceled) 
     
     
         22 . A system comprising:
 one or more near-isothermal compression (NIC) systems,
 each NIC system comprising a chamber, a mechanical piston disposed within the chamber, an incompressible fluid disposed within the chamber, and cooling means, 
 each NIC system being constructed to increase a pressure of a working fluid within the chamber via axial movement of the mechanical piston, 
 the incompressible fluid being disposed between the working fluid and a leading end of the mechanical piston during the pressure increase, 
 the cooling means being constructed to remove from the working fluid at least some heat generated during the pressure increase; and 
   one or more motors constructed to move the mechanical piston axially within the chamber of the one or more NIC systems.   
     
     
         23 . The system of  claim 22 , further comprising:
 a thermodynamic fluid circuit comprising a first heat exchanger, an expansion device, and a second heat exchanger,   the first heat exchanger being coupled to the one or more NIC systems so as to receive pressurized working fluid from the one or more NIC systems and being constructed to transfer heat from the pressurized working fluid flowing through the first heat exchanger,   the expansion device being coupled to the first heat exchanger so as to receive the working fluid from the first heat exchanger and being constructed to reduce a pressure of the working fluid flowing through the expansion device,   the second heat exchanger being coupled to the expansion device so as to receive the working fluid from the expansion device and being constructed to transfer heat to the working fluid flowing through the second heat exchanger, and   the second heat exchanger being further coupled to the one or more NIC systems so as to deliver heated working fluid from the second heat exchanger to the one or more NIC systems.   
     
     
         24 . The system of  claim 23 , wherein:
 each NIC system has at least one first port and at least one second port,   heated working fluid is delivered from the second heat exchanger to the chamber via the at least one first port, and   pressurized working fluid is supplied from the chamber to the first heat exchanger via the at least one second port.   
     
     
         25 . The system of  claim 22 , wherein:
 the cooling means is in thermal communication with only a first portion of the chamber distal from the leading end of the mechanical piston, and   a fluid volume of the first portion is equal to or less than a volume of the incompressible fluid within the chamber.   
     
     
         26 . The system of  claim 25 , wherein:
 prior to increasing the pressure, the working fluid fills the first portion of the chamber, and the incompressible fluid fills a second portion of the chamber between the first portion and the leading end of the mechanical piston, and   after increasing the pressure, the incompressible fluid fills the first portion of the chamber.   
     
     
         27 . The system of  claim 22 , wherein the working fluid is carbon dioxide, and the incompressible fluid is oil. 
     
     
         28 - 29 . (canceled)