Army Research Laboratory Adelphi, MD

Cogeneration Plant Installation

Contract Value: $1,022,000
Contract Type: Engineered Design

Project Date: February 2010
Compeletion Date: Februaury 2011

ACI was contracted by Ameresco Inc., to retrofit the Central Utility Plant at the US Army Garrison Adelphi Research Laboratory Center with a Combined Heat and Power (CHP) Cogeneration Facility.

The scope of work included demolition of existing high temperature hot water (HTHW) generator and existing chiller and preparation for the installation of two 1,100-kW Waukesha natural gas engines, two Cain heat recovery boilers, two plate and frame heat exchangers, four Rocore fan cooled radiators, & four water circulating pumps—one Aurora cooling water pump for each engine & one Dean HTHW pump for each boiler, along with installation of all associated mechanical piping, control valves, insulation, breeching, instrumentation, structural concrete & steel, & ventilation. The project required close coordination with a number of trades not directly under contract with ACI, whose work was directly dependent on ACI completing work as scheduled & providing concurrent access to work space.

The CHP is designed to operate year-round supplementing the electricity & HVAC needs of the Garrison. Engines generating electricity produce waste heat that the system recovers using two methods. The first method is to force the engine exhaust gas though a heat recovery boiler connected in series to the return side (lower temperature side) of the campus HTHW loop. The second method is to pass a closed cooling water loop between the engine & a heat exchanger connected to the return side (lower temperature side) of the heat recovery boiler. Both boiler & heat exchanger are used to increase the temperature of HTHW return to existing generators effectively reducing their load & increasing the efficiency of the entire system. The CHP is equipped with temperature & pressure sensing devices & automatic control valves that direct exhaust gas to the stack & cooling water to roof mounted radiators if the seasonally dependent campus heating load is negligible or satisfied by other means preventing interruption of generator operation.

Special provisions: complex piping, limited space, accelerated schedule. All work was completed on a stringent schedule with no interruption to their daily activities and no down time.

All change orders were customer initiated changes for additional work.