Abstract:

The objective of the paper is to present the modifications done in hy brid gr eenhouse solar dryers to make them more efficient. As hy brid dryers we re developed to ov ercome the various limitations of other types of solar dryers. Due to modifications in dryers, the effect on various heat transfer parameters like heat transfer coefficient, drying time, drying efficiency, etc. is studied and also encapsulated in the paper. It is found that in most of the hybrid dryers, the maximum temperature of the drying chamber is around 65–80°C. This shows the suitability of a hybrid dryer for drying high moisture crops. Also, the drying time for most of the crops is around 2–3 days, which shows the faster moisture removal rate inside the hybrid dryers. According to the literature studied, the maximum drying efficiency of a hybrid dryer is reported by about 35%. The paper also encapsulates the various relations/equations used by different researchers to carry out the thermal modeling and heat transfer analysis of greenhouse dryers.

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