Study on Influence Factors of Thermal Hysteresis in Paraffin Actuator

The paraffin characteristics have to be further investigated to understand how to optimize the performance of paraffin actuators. Based on an experimental apparatus for paraffin thermal expansion characteristics with water, the influences of cooling means and spring pressure on thermal hysteresis phenomenon in relationship curve of displacement vs. temperature during increasing and decreasing temperature cycles of paraffin have been studied. The results indicate that in order to reduce the degree of thermal hysteresis in paraffin, the cooling speed of cooling means isnpsilat too quick. On the premise of ensuring the backward motion of the piston toward its initial position, the smallest elasticity coefficient of a spring is adopted to diminish the degree of thermal hysteresis.