University of Oregon: Central Heat and Power Plant
Existing building retrofit, new construction; University of Oregon: Central Heat and Power Plant; Wood Harbinger
Engineering firm: Wood Harbinger
2013 MEP Giants rank: 67
Project: University of Oregon: Central Heat and Power Plant
Address: Eugene, Ore., United States
Building type: School (college, university)
Project type: Other
Engineering services: Automation & Controls, Code Compliance, Electrical/Power, Fire & Life Safety, HVAC, Lighting
Project timeline: August 2008 to October 2012
Engineering services budget: $300,000
MEP budget: $1.9 million
One of the main challenges encountered was to efficiently aid the University in developing major goals and a direction for the project. The University knew their systems for chilled water, power and steam were not meeting the current and future demands of the campus. The existing plant was using the water from the nearby Mill Race Stream for refrigeration equipment cooling which made maintenance incredibly time-consuming for plant operators. The Central Power Station (CPS) boiler plant had outlived its equipment life and the steam distribution system was becoming inadequate to deliver required steam to the campus. The electrical distribution system was also under capacity and needed expansion of a credible backup system.
The University’s stated goals for the project also presented challenges in itself. The State of Oregon required increased efficiency, redundancy in all systems, green design, and ease of system maintenance. Due to the nature of the original 1949/1964 steam plant building layout and structure, additional challenges arose with the construction and installation of the co-generation system. The first was limited space. The new system, which needed to provide twice the capacity along with a 2-story office complex, had to fit within the original steam plant structure. The building also had hollow floors, making it impossible to surround the new steam-turbine generator with concrete slabs to reduce external vibrations. Additionally, we discovered that over the past few decades as the University grew, the chilled water system connections varied from building to building causing disturbances with distribution system pressures and temperatures.
The University, additionally, needed the Central Power Station to maintain 24/7 operating 365 days a year and not disrupt campus life during the upgrade process.
Finally, the Central Power Station not only needed to provide heating and cooling services to meet the current campus demands but also last through the next 40 years of campus growth.
Wood Harbinger’s engineers tackled these challenges by leading a multi-day design charette with the design team, key stakeholders from the University, adjacent lease-hold property owners, and local utility district. The team listened and discussed each concern to gain a clear understanding of the University’s needs and expectations.
After a series of studies and investigations, including performing thermal load analyses, evaluating condition and capacity of over 24,000 ft of campus-wide tunnels, and investigating water system connections; the team developed design options for the new Central Power Station. They increased efficiency by having the co-generation unit follow steam load instead of electrical load, as well as having a plate and frame heat exchanger in the chilled water system provide “free cooling” for minimal cooling demand. The new system was able to increase steam pressure by utilizing an existing 12 in. – 20 psi steam header, increased distribution pressure to 60 psi, which required changing pressure regulators at each of the over 100 buildings – resulting in a significant increase in capacity. This overall system was also able to lower the boiler operating pressure from 225 to 150 psi, to increase boiler efficiency. Additionally, the chilled water plant was designed for expansion by including room for six future cooling towers, two future chillers, and a fourth standby generator.
To provide consistency and ease future maintenance of the new system, we helped discover the best connections for the chilled water distribution system and standardized this across the whole campus. We also wrote specifications to ensure that future installations would comply with the new standards.
To address the issues of budget, we assisted the University by defining the project and budget for their use in a presentation for State Legislation, which was ultimately successful. Additionally, we reused existing infrastructure whenever possible, saving approximately $2 million.
The team also designed a bar coding system to simplify maintenance, repair and replacement, where a simple scan would deliver the history, specifications, and function of any piece of equipment. Additionally, they created a hydraulic model of the entire campus chilled water system to assist in future modifications as the University grew. A phasing plan was used that allowed for 95% of the equipment to be installed while keeping the campus functional.
The electrical engineers designed switching configurations that eliminated power outages on the campus during construction. They also provided mathematical modeling of the entire system. This required a transient analysis, or swing-curve analysis, to predict the performance of each component so that specific settings of the protective relays and programming of the sequence of operations could be established.
Overall the team met the all the goals of the University through increasing efficiency, adding redundancy to all systems, and gaining operational cost savings. The chilled water system alone exceeded the required state energy code by 18%, garnered a $900,000 rebate from the local utility, and reduced the University’s carbon footprint by 7%. All these solutions helped achieve the University’s goals of minimal campus disruption and of having a Central Power Station that would fulfill their needs until 2049.