Research on flammability of R290/R134a, R600a/R134a and R600a/R290 refrigerant mixtures

As a natural substance, HCs (hydrocarbons) refrigerant have no destructive effect on ozone and has little impact on greenhouse effect. It is an ideal new refrigerant. R290 and R600a have been used to a certain extent, but hydrocarbon refrigerant has a high risk of flammability, which hinders its engineering application. This paper focuses on using hydrocarbon refrigerants as alternative refrigerants, taking R290 and R600a as the main research objects, adding refrigerant R134a to hydrocarbon refrigerants to study the flammability change of mixtures. The flammability limits of R290/R134a, R600a/R134a and R600a/R290 mixture refrigerants were measured under different components. In comparison, R134a had more obvious flammability inhibition effect on R290 than R600a. The influencing factors of the flammability limits of HCs and the estimation method of the flammability limits of mixtures with the average MAPEs ranged from 0.62% to 2.94% was discussed. In addition, the refrigeration cycle of HCs/R134a mixtures with various concentrations was simulated. The COP, volume refrigeration capacity per unit and condensation pressure of the mixtures had local maximum near the azeotropic point, respectively.