Andriyanto Setyawan^a,*

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-6, 2020, DOI:10.5098/hmt.14.22

Abstract In this paper, the effect of evaporating temperature on the void fraction and flow pattern of R290 in an evaporator of air conditioning unit has been studied. The analysis was carried out for evaporator diameter of 7.9 mm and 6.3 mm and cooling capacity of 2.64 kW and 5.28 kW. The analysis was conducted at evaporating temperature of -20°C to +5°C with an increment of 5°C. At the inlet of evaporator, the void fraction ranges from 0.932 to 0.984, whereas at the outlet the void fraction is 1. Testing the void fraction by using 3 available correlations gives the good… More >

Jing Hu^a,* , Mingxing Du^b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-7, 2020, DOI:10.5098/hmt.14.5

Abstract Inert gases are conveniently used for leak detection. Relative to CO₂, majority of the inert gases are non-condensable. It is of great significance to understand the effects of residual non-condensable gases on the performance of a refrigeration system. This paper investigates, both theoretically and experimentally, on the impact of residual non-condensable gases on the performance of a carbon dioxide (CO₂) evaporator and the system performance. A theoretical analysis indicates that residual non-condensable gases can convert homogeneous nucleation into a heterogeneous nucleation process and accelerate phase change, thus, reducing superheat or incipient boiling temperature. To investigate the influence of residual non-condensable… More >