Campus Utility System Improvements

Client: The University of Chicago

The University of Chicago continually improves the resiliency of their utility generation and distribution assets for their urban campus. These facilities include two steam generation facilities and three chilled water plants interconnected for an underground distribution network. A few of PRVN’s projects contributing to the improvement if reliability and sustainability include:.

Upgrade Boilers with New Burners and Economizers

The South Steam Plant, a 1920s vintage historic plant, has been modified several times over its life. As part of a continual effort toward environmental stewardship, Boilers 3 and 4 burners were modified to achieve ultra-low NOx performance. The burner throat was modified and gas pokers and swirlers were replaced for each burner and new induced flue gas recirculation (FGR) was added for reduction in NOx emissions. Modifications to the boilers also included installation of new flue gas stack dampers, removal of the existing air preheaters and installation of new economizers in each boiler’s flue gas breeching.

New Condensate Polishing System

Condensate return has a significant impact on the longevity of steam boilers and associated auxiliaries. To this end, new condensate polishing systems were installed at both the West Campus Combined Utility Plant (WCCUP) and the South Steam Plant (SSP) for use in removing impurities from the returned condensate. The polishers were sized and selected based on plant capacity and projected flow rates at campus peak loads. The condensate is returned to a “dirty” condensate tank in the existing plants. From these tanks, the condensate is pumped through the polishers to clean condensate storage tanks before returning to the deaerator and eventually the boilers. Removal of impurities has led to reduced boiler blowdown and wasted boiler water.

Campus Chilled Water Improvement Planning

Chilled water is provided to the campus buildings via a looped distribution network served from three central chilled water plants: the West Campus Combined Utility Plant (WCCUP), the South Campus Chiller Plant (SCCP), and a satellite plant within the Regenstein Library. The University of Chicago wished to identify and evaluate potential improvements to the chilled water distribution and building interface points and improve the operation of this system through control system modifications.

Following the study phase, the project initiated several improvements, including updated controls sequences at the plant and within the buildings. In addition, the University elected to add a tertiary pump bypass and automatic valves at Max Palevsky Residence Hall (three wings) as a test case for these improvements. PRVN then participated in testing of the control sequences and witnessed operational improvements. Lastly, PRVN authored the chilled water Standard Operating Procedures (SOP) for the campus system providing training for operations personnel.

Boiler Controls Replacement

The West Campus Combined Utility Plant steam system was operated from a control system that could not be upgraded or modified by the University. As a result, a new control system consisting of an Allen-Bradley ControlLogix platform was upgraded from the obsolete 1756-L6X controllers using ControlNet communications to the newest 1756-L8X controllers with A-B industrial Ethernet communications. The workstation HMI screens were upgraded to the latest version of Wonderware InTouch HMI software for both boilers and for the balance of plant systems. The project also consisted of renovating the existing WCCUP boiler plant systems to install new valves, instrumentation, and associated auxiliaries to support the upgrade of the Process Control System for the boilers and auxiliaries