An Investigation of Burst Strength of Pressure Vessel for R410A Rotary Compressor

The burst strength of rotary compressor pressure vessel directly affects the safety. Therefore, it is mandatory to ensure the strength of the pressure vessel. Major factors that determine the burst pressure of pressure vessel are stress concentration around the suction and discharge hole as well as its shape and thickness. In this study, stress concentration of the pressure vessel is investigated by means of finite element analysis. Moreover, actual hydrostatic burst test is carried out to confirm the burst pressure. Burst pressure of the pressure vessel can be increased by relieving the stress concentration around the suction and discharge hole. INTRODUCTION The planned phase-out of R22 refrigerant currently used in the refrigeration and air-conditioning industry is forcing compressor manufacturers to develop compressors suitable for new alternative refrigerants. The new alternative refrigerant R410A has higher-pressure characteristics than R22. Therefore, the safety must be ensured in the burst strength of compressor. And compressor shell is required to meet the safety requirement. For evaluating the safety requirement of the pressure vessel, UL sets forth the Hydrostatic Burst Pressure Test and Fatigue Test Analysis methods. [1] The present safety requirement for design pressure is that pressure vessel has no rupture at five times the maximum design operating pressure or three times abnormal pressures whichever is higher. [2] Engineering design target pressure as well as safety requirement for pressure vessel was established in order to confirm the safety and reliability. Hydrostatic burst pressure test is performed to obtain the actual burst pressure and to find out the stress concentration in the pressure vessel. Safety and reliability for the pressure vessel can be ensured by relieving the stress concentration and by optimal design of the pressure vessel. Fifteenth International Compressor Engineering Conference at Purdue University, West Lafayette, IN, USAJuly 25-28, 2000 335