Systems and methods for compression and expansion of gas

Abstract

Valves used for reciprocating gas compression and expansion and methods for operating them are provided. In some embodiments, these systems and methods can be used to recover energy in heat pumps, compressed gas systems, and pumped heat energy storage systems. In other embodiments, they may be used for gas compression or both gas compression and expansion.

What is claimed is: 
     
         1 . A valve system operable for use with a reciprocating machine, the valve system comprising:
 a first valve provided in a first valve housing and a second valve provided in a second valve housing;   the first valve housing comprising a first conduit, and the second valve housing comprises a second conduit;   the first valve comprising a valve plunger comprising a valve head and a stem and a ferromagnetic member provided on the stem;   the second valve comprising a valve plunger comprising a valve head and a stem and a ferromagnetic member provided on the stem;   wherein each of the valves comprise a first magnetic pole and a second magnetic pole and wherein the ferromagnetic member is moveable relative to the magnetic poles;   wherein the first valve housing and the second valve housing comprise separate housings that are in fluid communication via at least one of the first conduit, the second conduit, and a piston cylinder.   
     
     
         2 . The system of  claim 1 , wherein the first magnetic pole is provided a vertical position that is greater than a vertical position of the second magnetic pole. 
     
     
         3 . The system of  claim 1 , wherein the first valve housing and the second valve housing each comprise a portion of a fluid flow path and wherein first valve and the second valve are in the fluid flow path. 
     
     
         4 . The system of  claim 1 , wherein at least one of the first valve and the second valve comprise a solenoid and wherein the solenoid is provided with forced convective cooling in the fluid flow path. 
     
     
         5 . The system of  claim 1 , wherein at least one of the first magnetic pole and the second magnetic pole are secured by a frame. 
     
     
         6 . The system of  claim 1 , wherein the first and second conduits comprise portions of a bifurcated conduit in communication with a piston cylinder. 
     
     
         7 . The system of  claim 1 , wherein a piston provided in the piston cylinder is operable to perform work on a working fluid, and wherein the system is reversible such that work can be performed on the piston. 
     
     
         8 . A valve system operable for use with a reciprocating machine, the valve system comprising:
 a valve housing comprising a pressure vessel housing a valve;   the valve comprising a valve plunger with a valve head and a stem and a ferromagnetic member provided on the stem;   a first solenoid operable to receive an electric current and provide a magnetic force to the ferromagnetic member;   a second solenoid operable to receive an electric current and provide a magnetic force to the ferromagnetic member;   a first magnetic pole and a second magnetic pole and wherein the ferromagnetic member is moveable relative to the magnetic poles and the magnetic poles are operable to selectively control a vertical position of the valve head;   a first conduit and a second conduit in communication with the valve housing, wherein the valve is in selective communication with a seat provided between the valve housing and the second conduit; and   wherein a fluid flow path is provided that extends from the first conduit to the pressure vessel and to the second conduit, and wherein the first and second solenoids are provided in the fluid flow path.   
     
     
         9 . The valve system of  claim 8 , wherein the first magnetic pole is provided a vertical position that is greater than a vertical position of the second magnetic pole. 
     
     
         10 . The valve system of  claim 8 , wherein the fluid flow path is reversible. 
     
     
         11 . The valve system of  claim 8 , wherein at least one of the first magnetic pole and the second magnetic pole are secured by a frame. 
     
     
         12 . The valve system of  claim 8 , wherein the second conduit is provided in fluid communication with a piston cylinder at least when the valve is provided in an open position. 
     
     
         13 . The valve system of  claim 8 , further comprising a second valve housing comprising a second valve. 
     
     
         14 . The valve system of  claim 13 , further comprising a piston cylinder and wherein the piston cylinder is in fluid communication with the first valve housing and the second valve housing. 
     
     
         15 . A method of gas compression and expansion, the method comprising:
 providing a first chamber and a second chamber, the first chamber comprising a first valve operable to control fluid flow to and from the first chamber and the second chamber comprising a second valve operable to control fluid flow to and from the second chamber;   each of the first valve and the second valve being in communication with a solenoid and a magnetic pole;   providing a controller in communication with at least one of the first valve and the second valve;   determining, based on a measured reluctance of a magnetic circuit of at least one of the first valve and the second valve, a valve plunger position; and   adjusting with the controller at least one of timing and position of at least one of the first valve and the second valve.   
     
     
         16 . The method of  claim 15  wherein the valve plunger position between open and closed states is measured and controlled in sequential time intervals of an operating cycle. 
     
     
         17 . The method of  claim 15 , wherein an effective voltage across the solenoid is controlled by applying pulses having an intended duty cycle. 
     
     
         18 . The method of  claim 15 , wherein valve plunger position is determined using electrical measurements on the valves and a valve plunger position is controlled in a proportional-integral-derivative control feedback loop. 
     
     
         19 . The method of  claim 17 , wherein a preferred effective voltage is calculated based on a preferred target current and a length of the subsequent interval. 
     
     
         20 . The method of  claim 19 , further comprising a step of detecting a pressure reversal across a valve, and wherein the system is devoid of pressure sensors.