Sustainable on-site cooling-heating-power (CHP) systems for large multibuilding projects require a simplified design and implementation approach from conventionally designed mini-utility-type CHP systems employing large volume/footprint, costly, high thermal mass heat-recoverysteam- generators, and 24/7 stationary engineers.

This paper demonstrates the use of prefabricated, skidmounted hybrid steam generators with internal headers, fully integrated with low pressure drop heat extraction coils located in the gas turbine exhaust and employing environmentally benign heat transfer fluids. The proposed thermal tracking integrated CHP gas cooling system includes close-coupled plate-and-frame heat exchangers, pumps, and self-regulating controls, interconnected via a closed, low-pressure, nonvolatile recirculation loop capable of efficient year-round heat transfer to on-demand HVAC&R building heat sinks, including absorption chillers.

Available waste heat is transferred directly to a gas turbine exhaust, extraction heat exchanger, interconnected to a recirculating, closed-circuit, nonvolatile, low-pressure heat transfer fluid loop. Available waste heat is cascaded to serve multibuilding space cooling, heating, and domestic hot water loads, which permits maintaining high log-mean-temperature-differentials at the subject extraction coil, significantly lowering gas turbine back-pressure, and permitting significant life-cycle cost savings. These benefits were demonstrated during a recent, comparative CHP study of a 3.5 MW gas turbine installation at a central California university campus.

Units: Dual