Study on the operating characteristic of disc seal single screw pump used in energy recovery systems

As a new type of fluid machinery, the disc-seal single screw pump (DSSP) is vital for energy conversion in oil sludge energy recovery systems and natural gas liquefaction system due to the advantages of wide flow range, strong self-absorption and well adaptability to organic solid impurities. However, no research work has focused on the working mechanism and performance of this pump at present, which makes its application limited. In view of this, the in-depth theoretical study on the meshing characteristics and operating performance of the DSSP must be carried out. In this paper, the profile equations of the meshing pair and the working process mathematical model were established for the first time based on three-dimensional space meshing theory, coordinate transformation principle. By using this model, the working performance of this pump was investigated, and the influence mechanism of the profile parameters on the theoretic volume was analyzed. The results of the analysis show that DSSP has the best leakage characteristics when the seal disc rotation center fell on the screw rotor touchline. All these analyses can provide the theory basis for improving the performance of the pump and optimized design of the meshing pair.