Analytical Studies On Flow Coupling Of Air-conditioning Compressor Piping System

The compressor of the air-conditioning exterior is the heart of the whole system. The assisting pipes that connect the compressor vibrate due to the vibration caused by working compressor and flow coupling of the liquid in the pipes. The vibration of the assisting piping system not only undermines the comfortable life of people by causing noises and abnormal sound, but also consumes and degrades the assisting piping, which results in shorter life circle, posing a threat to people’s safety. To boost the reliability and stability of the air-conditioning piping system, the mechanical rationale and features of piping vibration should be clarified. Mechanization and characteristic produced by vibration should be known in air-conditioning pipe designBased on the relevant theories of structural dynamics and liquid dynamics, this thesis starts to study the coupling vibration mechanism caused by compressor’s piping of the air-conditioner and the dynamics of solid-fluid interaction 。First, a dynamic model of piping is built by utilizing the FEM, whose theoretical model and experimental model have been analyzed to guarantee the rationality and reliability of the dynamic model. Second, CFD, together with the boundary conditions, is used to analyze liquid dynamics in the piping system, so the inner-surface pressure is measured. Third, for pipe system, choose the pipe wall pressure as actuate, did harmonic response analysis, get the vibratory response of pipe system. Forth, conduct the experimental analysis on the ODS and compare it with the result calculated from flow coupling. To some extent, the two results are compatible. And the reasons for the final deviation will be discussed.Through analyzing the flow coupling of the pipes, this thesis reveals the mechanical rationale for the vibration in the air-conditioning piping system and proposes an analytical method for studying the piping vibration caused by the liquid. A convenient and effective way to address the noise problem in piping system occurring in real projects and an upgraded design are provided in this thesis.