NUMERICAL AND EXPERIMENTAL STUDY ON PLATE FORMING USING THE TECHNIQUE OF LINE HEATING

Nowadays manual and experiential technique patterns of line heating process could not meet the requirement of modern shipbuilding. Therefore, the automatic forming method is being an active research topic in manufacturing. An accurate and practical predicting method is an essential part of the automatic plate forming system. In the present work a numerical elasto-plastic thermo-mechanical model has been developed for predicting the thermal history and resulting deformation and residual stress field of line heating process. A moving Gaussian distributed heat source was used in the modelling to create a realistic simulation of the process. The transient temperature distributions were predicted using temperature-dependent material properties. The deformation and residual stress field were predicted based on the transient temperature distributions of line heating. Experiments were conducted to prove the validity of the numerical thermo-mechanical model. The final numerical results of temperature, deformation and residual stresses are in good agreement with experiment results. The proposed method presents a valuable reference for the study of similar thermal process.

CFD Model of Shell-and-Tube Latent Heat Thermal Storage Unit Using Paraffin as a PCM

This chapter validates the capability of CFD modelling technique to accurately describe processes in the thermal storage system with the PCM. For validation purposes, CFD modelling using FLUENT ANSYS was conducted and the predicted results were compared with the experimental and numerical data from the literature. The comparison between experimental and numerical results was carried out in terms of the temperature distributions and average volume of the PCM liquid fraction. Additionally, the detailed parametric study of the storage system with the PCM was performed and results obtained were discussed with dimensional correlations for the Nusselt number being proposed to be used in the designing process. Finally, a correlation was developed to estimate the total melting time at the thermal storage system.

Experimental and Numerical Investigations into Temperature Distributions and VOC Conversion Rate of RTO

As regulations for controlling VOCs (Volatile Organic Compounds) emissions have become more and more stringent, RTO (Regenerative Thermal Oxidizer) which involves heat exchange and storage, combustion and reaction processes has to be further optimised for enhancing the VOC treatment efficiency and reducing energy consumption. In this paper, influences of operating temperature distributions and internal flow fields on gas-out VOC concentration have been studied with experimental investigation and CFD numerical simulation. Experimental results shows that combustion temperature (around the combustor) plays more critical role than thermal storage bed temperature for affecting VOC flow-out concentration. By examining the internal flow and temperature distributions, modelling results demonstrate that fast heat transfer takes place in thermal ceramic beds and high temperature areas are formed around the combustor. At about 20 seconds after a bed working for gas-in flow, the heat transfer has demonstrated obvious attenuating. The research suggests that it is very challenging for simultaneously maintaining low gas-out VOC concentration and keeping low fuel consumption and low combustion temperature in RTOs.