The Optimal Selection of Capacity Sizing and Operational Strategy of CHP System for Public Buildings with Novel Heat Trading Using Local Thermal Storage

Abstract

The effects of capacity sizing and operational strategy of the CHP systems were numerically studied for optimal energy management of the CHP-based public building thermal energy network with novel heat trading using local thermal storage system (LTS). The mixed integer linear program (MILP) based model was developed to minimize the total operation cost of the entire buildings energy network at each time step based on the electricity and heat demands for public buildings in the considered energy network. The public building energy network considered in this study consists of three different buildings (hotel, hospital, and public office buildings) with a small individual CHP system for each building, a large central CHP system, and a LTS system connected to each building. The LTS makes it possible for each building consisting the same energy network to trade excess heat among buildings. The economically optimal capacity sizing of the small individual CHPs at each building, the central large CHP, and the LTS were suggested under various operational strategies and various arrangements of the several small CHPs (gas-engine, gas-turbine, and fuel-cell) installed in each building to minimize the operation cost.