Evaluation of the operational cost savings potential from a D-CHP system based on a monthly power-to-heat ratio analysis

摘要

This paper focuses on the analysis of a combined heat and power (CHP) system utilizing two power generation units operating simultaneously under differing operational strategies (D-CHP) on the basis of operational cost savings. A cost optimization metric, based on the facility monthly power-to-heat ratio (PHR), is presented in this paper. The PHR is defined as the ratio between the facility electric load and thermal load. Previous work in this field has suggested that D-CHP system performance may be improved by limiting operation of the system to months in which the PHR is relatively low. The focus of this paper is to illustrate how the facility PHR parameter could be used to establish the potential of a D-CHP system to reduce operational cost with respect to traditional CHP systems and conventional systems with separate heating and power. This paper analyzes the relationship between the PHR and the operational cost savings of eight different benchmark buildings. Achieving operational cost savings through optimal operation based on monthly PHR for these building types can enhance the implementation potential of D-CHP and CHP systems. Results indicate that the PHR parameter can be used to predict the potential for a D-CHP system to reduce the operational cost.