Influence of flow regime and thermal power on residence time distribution in tubular Joule Effect Heaters

摘要

To improve treatment homogeneity in tubular Joule Effect Heater (JEH), geometric modifications could be used even in laminar regime inducing flow perturbation and mixing.As a response variable, residence time distribution (RTD) is an important parameter and it has been commonly used in determining the performances of industrial heat exchangers.In present work, our objectives were (i) to investigate the impact of processing conditions (flow regime, heat flux) on RTD in an industrial JEH equipped with smooth and modified tubes, (ii) to contribute to the estimation of treatment homogeneity versus global energetic performances of heat exchanger and (iii) to validate a general reactor model.Analytical solution and systemic analysis of RTD signals were reported. The evolutions of mean reduced variance, β~2 against efficiency number, Eff for smooth (β~2 = 0.00129 • Eff- 0.0300, R~2 = 0.992) and modified (β~2 = 0.000547 Eff- 0.0169, R~2 - 0.979) tubes exhibited a similar and linear relationship. Under the conditions investigated (38 < Re < 10,000, 4