| 摘要 |
A method and system for lubricating a positive displacement expander of compressed gas comprises introducing into an expansion chamber of the machine a lubricant, e.g. an oil or aqueous liquid, whose pour point temperature is greater, by e.g. 50 C, than the machine operating temperature in the expansion chamber as determined by the expanding gas causing the lubricant to freeze adhere to the chamber internal surfaces. The frozen lubricant becomes fluid under increased pressure at a point of contact of the working surfaces and then refreezes when the surfaces separate. Reduction in the quantity of lubricant is realised e.g. to 0.0005% intake volume and dis-entrainment or separation of lubricant from the gas exhausted from the machine is largely avoided. May be used in at least scroll, screw or vane machines. The lubricant inlet temperature may be adjusted. |
