Analysis Of Leakage Character Of A Labyrinth Piston Compressor

A labyrinth seal is a non-contacting circumferential seal utilizing a tortured path for flow between the stationary and rotating (or reciprocating) parts. The design utilizes a series of pressure drops to reduce the leakage. They are commonly found in turbines and compressors as well in some pumps. A reciprocating compressor using labyrinth seal (Labyrinth Piston Compressor, LPC) can compress and transport gases in an oil-free way. It has many advantages, such as non-lubricated maintenance, no friction loss, no hot spots, minimal wear and tear, and so on. In order to improve the efficiency of a LPC and to minimize the labyrinth seal leakage, a series of basic theoretic research should be carried on, such as: finding an exact method for predicting the leakage of a LPC, understanding the seal principle in the labyrinth path and investigating how factors affect the seal performance.This paper concerns the basic study of a LPC. Firstly, A new method for predicting the leakage of the compressor has been developed and solved by an iterative Visual C++ program, the simple analytical and explicit method is shown to provide realistic results which agree with measurements. Then, a CFD model of the labyrinth seal is established, several seal models are numerical simulated in FLUENT, and the regularity of affections of the parameters, such as discharge pressure, shape of teeth and cavities, cavity inclination, labyrinth clearance, rotate speed and numbers of seal teeth are discussed in detail. Therefore, the study provides a better understanding of the leakage flow in labyrinth seals and a basis for design and optimize of the LPC structure.