Single stage reciprocating piston compressor with cooling

A method of cooling a single stage reciprocating piston compressor that pressurizes a working fluid comprising a gas, the method comprising:

• injecting a first volume of a cooling fluid having a composition different from the working fluid into a first compression chamber of the single stage reciprocating piston compressor, wherein the first compression chamber contains a first portion of the working fluid;
• and wherein the first volume of the cooling fluid is injected:
• during a first intake stroke of a reciprocating piston in the first compression chamber, while the working fluid is being drawn in to the first compression chamber, or during a first compression stroke of the reciprocating piston in the first compression chamber;
• wherein the working fluid is pressurized by the first compression stroke of the reciprocating piston in the first compression chamber, to produce a first pressurized mixture comprising the first portion of the working fluid and the first volume of the cooling fluid in the first compression chamber;
• and
• discharging the first pressurized mixture from the first compression chamber in response to the first pressurized mixture satisfying a first discharge condition;
• and
• automatically controlling delivery of the first volume of the cooling fluid injected into the first compression chamber for a successive first intake stroke or a successive first compression stroke of the reciprocating piston in the first compression chamber, in response to a first control condition of the first pressurized mixture.