عنوان مقاله [English]
Positive displacement compressors are one of the most important and expensive components of the vapor compression refrigeration cycle, it is very important to protect this equipment during operation and against destructive phenomena. The compressive mechanism of this type of compressors is based on the compressibility of gases and the pressure increases by reducing the volume and compressing the refrigerant gas. One of the destructive phenomena that causes main failure and mechanical damage to this type of compressors is the liquid flood back that occurs when liquid refrigerant returns to the compressors suction line. This research focuses on design, fabricate and test a protecting system to protect the compressor against liquid flood back. This protecting system is based on electronic processing of effective parameters including operating pressure, operating temperature, superheat temperature, superheat degree and type of refrigerant. The protection system processes based on the relevant thermodynamic formulas and issues the appropriate command based on the processing result. Validated researches prove electronic processing method is better than mechanical processing. The protection system installed successfully on a 30 ton Positive displacement compressor with R-22 refrigerant.