Oil separator are two series: one is the use of different YF series of oil and refrigerant density suddenly increases when the channel cross-section, the flow rate dips, weight larger droplets fall under the influence of gravity; the oil inside the gas flow direction change or centrifugal effect, so the larger droplets density separation; use refrigerant liquid or cooling pipes, the mixed gas cooling, which entrained oil vapor condenses into droplets larger particles; the use of filtration equipment filtration. Second, the TL series by the action of special baffle, is a high pressure ammonia lubricant preliminary separation under the action of centrifugal force, the device further separated by an upper layer of stainless steel packing.