Biodiesel Fueled Engine Generator With Heat Recovery

Abstract

Carnegie Mellon University’s departments of Architecture and Mechanical Engineering have teamed with Milwaukee School of Engineering’s Mechanical Engineering department to design and install a biodiesel fueled engine-generator with heat recovery equipment to supply electric and thermal power to an office building on campus, the Intelligent Workplace (IW). The installation was completed in early September 2007, and is currently being commissioned. Full scale testing will begin in early 2008. The turbocharged diesel engine-generator set is operated in parallel with the local electric utility and the campus steam grid. The system is capable of generating 25 kW of electric power while providing 18 kW of thermal power in the form of steam from an exhaust gas boiler. The steam is delivered to a double-effect Li-Br absorption chiller, which supplies chilled water to the IW for space cooling in the summer or hot water for space heating in the winter. Furthermore, the steam can be delivered to the campus steam grid during the fall and spring when neither heating nor cooling is required in the IW. Additionally, thermal energy will be recovered from the coolant to provide hot water for space heating in the winter, and for regenerating a solid desiccant dehumidification ventilation system in summer. All relevant temperatures, pressures, and flows for these systems are monitored via a building automation system. Pressure versus time measurements can be recorded in each cylinder of the engine. Emissions of nitric oxide (NO), nitrous oxide (NO2), Particulate Matter (PM), and carbon dioxide (CO2) are also monitored. Upon completion of this installation and the system performance testing, the operation of the engine generator with its heat recovery components will be integrated with the other HVAC components of the IW including a parabolic trough solar thermal driven LiBr absorption chiller, a solid desiccant dehumidification ventilation system, and multiple types of fan coils and radiant heating and cooling devices. This energy supply system is expected to reduce the IW’s primary energy consumption by half in addition to the 75% energy savings already realized as compared to the average US office space.