EXPERIMENTAL INVESTIGATION ON CAPILLARY TUBE FOR A DOMESTIC FREEZER WITH A MIXTURE OF R290/R600a (50/50) AS A SUBSTITUTE FOR R134a

摘要

The hydrocarbon mixture of R290/R600a (HCs) with a mass ratio of 50/50 is regarded as a promising long-termrnrefrigerant to replace R134a in domestic freezers. Due to the property difference between R134a and HCs, thernactual length of the capillary tube should be renewed suitable for this alternative mixture; otherwise, the freezerrnsystem may have lower thermal performance than the R134a system. During the investigation a domestic freezerrnof 150L was used to evaluate the inner temperature distribution and the thermodynamic cycle performances ofrnR290/R600a (50/50) under conditions with different lengths of the capillary tube. The experimental resultsrnindicate that the R290/R600a (50/50) mixture with the optimized capillary length, which was obtained from thernsimulation, offers higher energy efficiency with a lower discharge temperature than the original R134a system.rnThe proposed mixture is proven to be a suitable long-term alternative in terms of its excellent thermodynamicrncycle performances.