Abstract: In the simulation transportation sweep frequency vibration experiment of a household air conditioning outdoor unit project in the development stage, the phenomenon of tube breaking occurred at the root of the liquid outlet pipe of the electronic expansion valve. Through finite element simulation analysis, it was found that the electronic expansion valve assembly in the original scheme had an overall up and down mode at the frequency of 77 Hz, which was the main cause of tube breaking. In order to solve this problem, an optimization scheme to strengthen the welding position of the pipe is proposed. The simulation results show that no overall up and down modes appear within the experimental frequency range after optimization, and the stress at the original broken pipe position is reduced by 73.1% compared with the original pipe scheme. The experimental results show that the reinforced pipe optimization scheme is effective and can avoid the problem of broken pipe of the electronic expansion valve outlet pipe of this model.

Key words: Household air conditioning, External machine, Simulated transportation, Sweep frequency vibration, Broken tube