1824, RichardTrevithick first put forward the idea of air refrigeration cycle, but this device was not built. 1834, JacobPerkins developed the vapor compression refrigeration cycle for the first time and obtained a patent. In the designed vapor compression refrigeration equipment, ether is used as refrigerant. With the steam compression refrigeration equipment invented by JacobPerkins officially put into use, some practical refrigerants have been developed since the 1930s. In 1930s, the first refrigerator developed by Perkins used rubber fraction as industrial solvent. This fluid was chosen mainly because it was relatively easy to obtain at that time. Therefore, from the early days, "availability" has been an important criterion for refrigerant screening.