Abstract: The start-up transient of the air-conditioning constant speed scroll compressor will produce a large starting torque, which will cause a large stress on the piping. Identifying the starting torque of the compressor is of great significance for predicting and reducing piping stress. Firstly, simplify the complicated compressor and piping system into a single degree of freedom torsion model. Secondly, based on the modal test at different positions of the compressor, the compressor torsion transfer function is calculated. Finally, according to Duhamel's integral and load function, the starting torque of the compressor is identified, maximum error 20%, which provides load for subsequent simulation.

Key words: Compressor start, Single degree of freedom torsion model, Torsion transfer function, Identification of starting torque