Modelling of latent heat storage by phase change materials for solar drying processes
Final Report Abstract
The project investigated solar drying systems with latent heat storage and compared their performance to conventional solar dryers. The main goal was to simulate the dynamics of these systems and evaluate the effect of incorporating latent heat storage for improved performance. Detailed mathematical models were developed for the solar air heater, latent heat storage unit, and fixed-bed dryer. These models were validated against experimental data and used to simulate solar drying of agricultural products in Germany and Kenya. The results showed that latent heat storage could help reduce temperature fluctuations and improve moisture uniformity, especially when used with larger collector sizes, though it increased drying time. For wheat drying in Germany, larger collectors reduced drying time but caused greater temperature variation, while the energy storage helped smooth out temperature peaks, though its impact on moisture homogeneity was modest. For maize drying in Kenya, the combination of large collectors and latent heat storage units improved moisture uniformity and effectively avoided excessive temperatures. The project also demonstrated the importance of correctly sizing components, as the storage can effectively protect products from excessive temperatures but may not reduce drying time. The developed programs were translated into Fortran and incorporated into TRNSYS Types, facilitating faster simulations and broader usage. Overall, the project highlighted the potential of latent heat storage in solar drying systems for enhancing temperature regulation and moisture uniformity, providing valuable insights for future solar dryer designs.
Publications
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A comparison of steady-state and transient modelling approaches for the performance prediction of solar air heaters. Energy Conversion and Management: X, 16, 100327.
Román, Franz & Hensel, Oliver
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Mathematical modelling of a latent heat storage: Influence of PCM thermal conductivity and enthalpy-temperature relationship. Journal of Energy Storage, 94, 112424.
Román, Franz; Munir, Zeeshan & Hensel, Oliver
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Performance comparison of a fixed-bed solar grain dryer with and without latent heat storage. Energy Conversion and Management: X, 22, 100600.
Román, Franz; Munir, Zeeshan & Hensel, Oliver
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Solar drying with latent heat storage (1.0.0). (Python and Fortran programs for the simulation of solar air heater, latent heat storage and fixed-bed dryer)
Román, F. & Hensel, O.
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Latent-dry: Solar drying with latent heat storage in Python, Fortran and TRNSYS. SoftwareX, 29, 101999.
Román, Franz & Hensel, Oliver
