Influence of inlet vapour quality perturbations on the transient response of flow-boiling heat transfer
نویسندگان
چکیده
Abstract The effect a transient heat flux has on in-tube boiling not been studied extensively for some refrigerants commonly proposed use in concentrated solar power organic Rankine cycle systems. In this study, the of abrupt step changes (upwards and downwards) inlet vapour quality to flow-boiling test section transfer coefficient was considered. Tests were conducted with R-245fa at saturation temperature 35°C an 800 mm horizontal smooth tube inner diameter 8.31 mm constant 7.5 kW/m2. Initial qualities ranged between base values 0.15 0.40 mass fluxes 200 300 kg/m2s. Baseline coefficients steady-state conditions determined, followed by series transient-state response investigations. For these, sharp upward downward perturbations It found that size magnitude 0.13 quality, actual differed from expected quasi-steady-state during transient. During step, it 8.7 11.7% higher than coefficient, while 9.3 26.0% lower 200 kg/m2s, depending initial quality. 300 kg/m2s, 7.2% 16.7% 13.8 17.8% respectively.
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ژورنال
عنوان ژورنال: International Journal of Heat and Mass Transfer
سال: 2021
ISSN: ['1879-2189', '0017-9310']
DOI: https://doi.org/10.1016/j.ijheatmasstransfer.2021.121017