Modeling of temperature patterns in a modified traditional grain storage structure (Kihenge)

A model for the prediction of weather induced temperature patterns in grain stored in a modified traditional small scale store has been developed. The studied modified store called "Kihenge" in Tanzania is one which is fairly air-tight, preventing free moisture intake and air inlet from the external surroundings. Chapter 1 introduces the importance of temperature in grain storage. In chapter 2 a review of previous temperature prediction models in grain stores has been made. Theory of heat transfer to and from the grain store is presented in chapter three. Both external and internal possible sources of heat transfers that might be responsible for inducing temperature changes in the stored grain are discussed. Development of a two-dimensional model for the prediction of grain temperature patterns in the modified traditional grain store is presented in chapter 4. The model assumes that conduction is the main heat transfer mechanism inside the stored grain bulk, and the heat changes are assumed to be solely due to the external ambient weather variations. Internal heat sources have been neglected. Chapter 5 deals with the results of the model and its validation. A computer programme written in Turbo Pascal version 6.0 was used to generate model results. Data for the validation of the model were obtained from a field experiment. Comparison of the predicted with measured temperature gives good agreement. The result shows that the model developed can be useful for prediction of weather-induced grain temperature patterns, in modified traditional grain storage systems located in the tropics. The mean deviation of simulated from experimental grain temperature results ranged between - 0.1 °C and + 0.5 C. The range of maximum absolute deviation of simulated from experimental grain temperature results is between 0.6 °C and 2 °C. Possible improvements on the developed model are indicated.