Date of Award
Doctor of Philosophy
Agricultural and Biosystems Engineering
Stephen J. Marley
Simulation modeling leads to a better understanding of the energy system, facilitates evaluation of the effects of complex interactions on system performance, and provides useful information on effects of design changes on the long term viability of the system. The objective of this study was to develop a simulation model of a biofueled energy system: (a) to predict design and seasonal energy requirements of the system; (b) to predict the seasonal efficiency of the biofueled boilers; (c) to perform economic analyses of the biofueled energy system (based on life cycle savings or present worth analysis);A simulation model of a biofueled energy system (BIOMOD) was developed to assist potential users of biofuel energy, and to perform parametric analyses of the most critical and uncertain variables of a biofueled energy system. BIOMOD consists of three submodels namely THERM, SIMPSE, and CYCLE. THERM predicts the hourly heating load at various bin temperatures, and design as well as seasonal energy requirements of the building envelope. SIMPSE simulates boiler operation and predicts the seasonal efficiency of biofueled space heating boilers. CYCLE performs the life cycle cost analysis of a biofueled energy system;To validate the THERM submodel, the measured seasonal load (November 1989-March 1990) of the McNAY Research Center residence was compared with the predicted heating load. The THERM prediction of seasonal load was in good agreement (within 6.5%) with the measured load. To validate the SIMPSE submodel, the measured seasonal efficiencies of the McNAY biofueled boiler for the months of December, January, February and March 1990 were compared with the model predictions. The SIMPSE predictions were within 3% of the measured results;About one hundred runs of SIMPSE were made to predict the performance of the biofueled boiler at various combinations of design and operating variables. The results were plotted to be easily accessible to biofueled boiler designers and operators, to assist them in obtaining higher boiler efficiency. CYCLE was used to perform the life cycle cost analysis of the McNAY biofueled energy system.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Ahmad, Munir, "Simulation modeling of a biofueled energy system " (1990). Retrospective Theses and Dissertations. 9387.