### Leakage Model of Axial Clearance and Test of Scroll Compressors

WANG Jianji (王建吉), LIU Tao (刘涛)

1. (1. School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
2. Mechanical and Electronic Engineering Department, Long Dong University, Qingyang 745000, Gansu, China)
2. (1. School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
2. Mechanical and Electronic Engineering Department, Long Dong University, Qingyang 745000, Gansu, China)
• Online:2020-08-28 Published:2020-07-29
• Contact: LIU Tao (刘涛) E-mail:liutao1971@lut.cn

Abstract:  Leakage clearance plays an important role in guaranteeing high efficiency of scroll compressors. In view
of the shortcomings of the existing leakage models of axial clearance of scroll compressors, a modified Fano flow
model and a turbulence model are presented based on the flow characteristics of fluid in the leakage passage under
actual working conditions. Firstly, according to the Fano flow energy equation and the turbulence theory, two kinds
of leakage models, Fano flow model and turbulence model, of axial clearance are established. Then, the established
models are verified through an experimental platform established to measure the axial clearance leakage in the
working process of a scroll compressor, and the measured values are compared with the values obtained from the
two theoretical models. Finally, the effect of such factors as pressure difference, clearance amount, spindle speed
on the axial clearance leakage is analyzed. Results show that the two established models can precisely reflect the
variation law of axial clearance leakage of scroll compressor under different working conditions. In particular, the
Fano flow model is more suitable for predicting the clearance leakage when the spindle speed is low (less than
3 500 r/min) and the clearance is small (less than 0.025 mm), whereas the turbulence model is suitable for high
spindle speed (more than 3 500 r/min) and large clearance (more than 0.025 mm).

Key words: scroll compressor| axial clearance| leakage model| mass flow rate

of the shortcomings of the existing leakage models of axial clearance of scroll compressors, a modified Fano flow
model and a turbulence model are presented based on the flow characteristics of fluid in the leakage passage under
actual working conditions. Firstly, according to the Fano flow energy equation and the turbulence theory, two kinds
of leakage models, Fano flow model and turbulence model, of axial clearance are established. Then, the established
models are verified through an experimental platform established to measure the axial clearance leakage in the
working process of a scroll compressor, and the measured values are compared with the values obtained from the
two theoretical models. Finally, the effect of such factors as pressure difference, clearance amount, spindle speed
on the axial clearance leakage is analyzed. Results show that the two established models can precisely reflect the
variation law of axial clearance leakage of scroll compressor under different working conditions. In particular, the
Fano flow model is more suitable for predicting the clearance leakage when the spindle speed is low (less than
3 500 r/min) and the clearance is small (less than 0.025 mm), whereas the turbulence model is suitable for high
spindle speed (more than 3 500 r/min) and large clearance (more than 0.025 mm).

CLC Number: