Liquid pump

Abstract

Embodiments relate to architectures for pumps responsible for introducing liquid into cylinders reversibly configurable to perform gas compression or expansion. Particular embodiments maintain liquid flow rates in the face of the different pressure profiles (Δ-P) encountered during various portions of gas compression and gas expansion cycles. In some embodiments, the pump comprises multiple pumping elements per cylinder, at least one pumping element separable with a clutch and designed to spray/not spray during portions of compression/expansion cycles. Embodiments may employ phase difference(s) between the multiple pumping elements to introduce liquid in a desired manner. Mechanisms allowing adjustment in phase of multiple pumping elements, are also disclosed. The liquid may be introduced through sprayers arranged in rings in the cylinder, with rings (or partitions thereof) dedicated to spraying during different portions of compression and/or expansion. Embodiments may flow liquid to a gas compression/expansion cylinder via an intervening chamber of changeable volume.

What is claimed is: 
     
         1 . An apparatus comprising:
 a liquid pumping element in fluid communication with a cylinder and coupled via a phaser to a crankshaft of a reciprocating member, such that a timing of liquid injection into the cylinder in an absence of combustion can be adjusted relative to a location of the reciprocating member within the cylinder.   
     
     
         2 . An apparatus as in  claim 1  wherein the reciprocating member within the cylinder defines a gas compressor. 
     
     
         3 . An apparatus as in  claim 1  wherein the reciprocating member within the cylinder defines a reversible compressor/expander. 
     
     
         4 . An apparatus as in  claim 1  wherein the phaser comprises a planetary gear set. 
     
     
         5 . An apparatus as in  claim 1  wherein the liquid pumping element comprises a cam. 
     
     
         6 . An apparatus as in  claim 5  wherein a shape of the cam produces a liquid injection event occupying a smaller crank angle range than a liquid intake event. 
     
     
         7 . An apparatus as in  claim 5  wherein a shape of the cam determines a spray profile. 
     
     
         8 . An apparatus as in  claim 1  wherein the liquid pumping element comprises a plunger within a sleeve. 
     
     
         9 . An apparatus as in  claim 8  lacking a seal between the plunger and the sleeve. 
     
     
         10 . An apparatus as in  claim 1  wherein the liquid pumping element further comprises a spring. 
     
     
         11 . An apparatus as in  claim 1  wherein the liquid pumping element is in fluid communication with a ring of liquid sprayers arranged in a cylinder wall. 
     
     
         12 . An apparatus as in  claim 11  wherein the cylinder comprises a single piece. 
     
     
         13 . An apparatus as in  claim 11  wherein the timing of liquid injection into the cylinder is adjusted to avoid spraying when the reciprocating member covers the ring of liquid sprayers. 
     
     
         14 . An apparatus as in  claim 11  wherein the liquid pumping element is in fluid communication with a plurality of rings of liquid sprayers arranged in the cylinder wall. 
     
     
         15 . An apparatus as in  claim 14  wherein the plurality of rings are bunched near Top Dead Center (TDC). 
     
     
         16 . An apparatus as in  claim 1  further comprising a spline coupling the liquid pumping element to the crankshaft. 
     
     
         17 . A method comprising:
 placing a pumping element in mechanical communication with a crankshaft of a reciprocating member to flow liquid to a sprayer in a cylinder wall in an absence of combustion; and   adjusting a phase of the pumping element relative to the crankshaft.   
     
     
         18 . A method as in  claim 17  wherein:
 the pumping element comprises a plunger in mechanical communication with the crankshaft via a cam; and 
 adjusting the phase of the pumping element comprises actuating the cam with a planetary gear. 
 
     
     
         19 . A method as in  claim 17  wherein a shape of the cam results in a liquid injection event occupying a smaller crank angle range than a liquid intake event. 
     
     
         20 . A method as in  claim 17  wherein a shape of the cam results determines a spray profile. 
     
     
         21 . A method as in  claim 17  further comprising biasing the pumping element with a spring. 
     
     
         22 . A method as in  claim 17  wherein the sprayer is arranged in one of a plurality of rings of a cylinder wall comprising a single piece. 
     
     
         23 . A method as in  claim 17  wherein the phase of the pumping element is adjusted to avoid spraying when a piston covers the sprayer. 
     
     
         24 . A method as in  claim 22  wherein the plurality of rings are bunched proximate to Top Dead Center (TDC). 
     
     
         25 . A method as in  claim 17  wherein the phase is adjusted according to a pressure ratio.