Paper Conference

Proceedings of ASHRAE/IBPSA-USA Building Simulation Conference


Energy Modeling of a Combined Cooling, Heating and Power Plant Using the Evergreen Building Energy Simulation Tool

Xin Hu, Xiang Liu, Liangcai Tan
Pacific Gas & Electric, San Francisco, CA
Nexant, San Francisco, CA
HDR Architecture Inc., San Francisco, CA

Abstract: This paper describes the energy modeling of a combined cooling, heating, cooling and power (CCHP) plant system using an energy modeling tool - EverGreen Building Energy Simulation Tool (EBEST). The project is a large commercial building with mixeduse in a warm marine climate using a CCHP plant, consisting of a micro-turbine and an absorption chiller. EBEST was used to run simulations of the CCHP systems with different turbine sizes and to compare them with a variable refrigerant flow system and a conventional chiller and boiler system. The simulation results indicate that although the CCHP system is energy-efficient and cost-effective for the life-cycle costs in general, it does not fit the situation discussed in this article, which has warm weather and low space heating needs. The effects of different CCHP turbine sizes on energy use and costs are also discussed in this paper. Both modeling and theoretical thermal balance equations were used to analyze the optimal CCHP size. This paper also demonstrates how to use energy modeling to guide the project design to achieve optimal energy performance and how to evaluate energy performance according to the Green Building Certification Institute (GBCI) Leadership in Energy and Environmental Design (LEED) guidelines during the design phase.
Pages: 362 - 369