Evaluation of combined heat and power (CHP) systems performance with dual power generation units for different building configurations

Abstract

SUMMARY This paper evaluates the economic, energetic, and environmental feasibility of using two power generation units (PGUs) to operate a combined heat and power (CHP) system. Several benchmark buildings developed by the Department of Energy simulated using the weather data for Chicago, IL, are used to analyze the proposed configuration. This location has been selected because it usually provides favorable CHP system conditions in terms of cost and emission reduction. For the proposed configuration, one PGU is operated at base load to satisfy part of the electricity building requirements, whereas the other is used to satisfy the remaining electricity requirement operating following the electric load. The dual-PGU CHP configuration (D-CHP) is modeled for four different scenarios to determine the optimum operating range for the selected benchmark buildings. The dual-PGU scenario is compared with the reference building using conventional technology to determine the benefits of this proposed system in terms of operational cost, primary energy reduction, and carbon dioxide emissions. The D-CHP system results are also compared with a CHP system operating following the electric load (FEL) and base-loaded CHP system. For three of the selected buildings, the proposed D-CHP system provides comparable or greater savings in operating cost, primary energy consumption, and carbon dioxide emissions than the optimized conditions for base loading and FEL. In addition, the effect of operating the D-CHP system only during certain months of the year on the overall operational cost is also evaluated. Results indicate that not operating the D-CHP system for the months where the thermal load is too low is beneficial for the overall system performance. Copyright © 2012 John Wiley & Sons, Ltd.