Closed-loop oscillating heat pipes are a type of heat exchanger that transfers heat from a hot source to a cold source by evaporating and condensing a fluid. In many studies using conventional refrigerants, the thermal performance of oscillating heat pipes has been investigated. In this study, due to the negligible environmental effects of the refrigerant R600a and the tendency to use it in the refrigeration industry, this refrigerant was used and the effects of evaporator temperature on the performance of the oscillating heat pipe were investigated. For this purpose, a laboratory closed-loop oscillating heat pipe with three reciprocating cycles was constructed and in addition to conducting experiments, the performance of the constructed device was also simulated numerically. The governing equations were numerically solved using the finite volume method in the ANSYS-Fluent software. In this analysis, the flow was considered turbulent and had two phases of liquid and vapor. The condenser temperature was 15 and the evaporator temperature was changed between 30 and 80 degrees. The results showed that at an evaporator temperature of 30 degrees Celsius, the heat transfer rate was 0.9 watts, and with an increase in the evaporator temperature to 80 degrees, the heat transfer increases to 10.8 watts. A further increase in the evaporator temperature may bring the device to the drying limit.