Kapil Dev Choudhary, Shyam Sunder Yadav^† , Mani Sankar Dasgupta

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-10, 2021, DOI:10.5098/hmt.16.14

Abstract In the current work, we simulate the condensation of supercritical CO₂ during its high speed flow inside two different converging-diverging nozzles. We use the homogeneous equilibrium method and the classical nucleation theory based non-equilibrium phase change model for this purpose. The simulation results indicate significant influence of the nozzle inlet condition, nozzle shape and the fluid thermophysical behaviour on the nonequilibrium conditions prevailing inside the nozzles. We observe very low, ∼0.15 K, supercooling for the flow of CO₂ inside the Claudio Lettieri nozzle compared to the supercooling of ∼3 K observed for the Berana nozzle. Very… More >

Panpan Zhao^1,*, Dongdong Wang², Dao Zhou¹, Huan Zhang¹, Yun Sun¹

Energy Engineering, Vol.117, No.4, pp. 209-224, 2020, DOI:10.32604/EE.2020.010567 - 31 July 2020

Abstract A R1234ze(E) based mixture was investigated as a promising environmental solution to enhance system performance of a transctitical organic Rankine cycle(TORC). The main purpose of this study is to research the thermodynamic properties of TORC system using R1234ze(E)/R134a mixtures with various mass fraction of R1234ze(E) when recovering engine exhaust heat. R1234ze(E) was selected due to its zero ozone depletion potential, relative lower global warming potential and it can remedy the thermodynamic properties of traditional working fluid R134a. Thermal analysis and optimization about expander inlet temperature and pressure of TORC, mass fraction of R134a in R134a/R1234ze(E)… More >