university of calgary central heating and cooling plant energy efficiency upgrades
The University of Calgary undertook a campus-wide program to reduce energy consumption. The work of this project includes measures specific to the Central Heating and Cooling Plant (CHCP) including the Bow River Pump Station (BRPS).
The CHCP provides campus-wide building cooling via a circulating chilled water loop. The chilled water is cooled via four refrigeration chillers using Bow River water as a condensing medium for refrigerant in the chillers. In the winter and shoulder seasons, river water is used in a plate heat exchanger as a free cooling device or ‘free chiller’.
Electrical supply and heating is provided by a natural gas co-gen turbine. The cogeneration plant produces a large amount of ‘free heat’, with boilers supplementing the high temperature high pressure hot water heating system which is distributed in the utility tunnel to campus buildings where it is used for building heating systems.
Water Street Engineering Ltd. (WSE) was engaged as a sub-consultant to SES Consulting to develop energy efficiency concepts for implementation at the CHCP and BRPS. WSE subsequently completed detailed design of the piping and instrumentation changes to implement the measures. WSE also issued control narratives for the programming changes required.
The measures implemented included:
- Speed optimization of the Bow River Pump Station to control the number of pumps operating and pump rotational speeds to correspond to their most efficient operating points.
- Variable volume pumping of the supply to the off-season plate heat exchanger.
- Alternate cooling water supply to the turbine cooling system to re-use process waste water for winter cooling.
- Reduction in irrigation system / Olympic Oval supply pressures.
The completed installation is expected to reduce electrical energy consumption by 900 MWh/yr and reduce withdrawls from the Bow River by up to 10%.
Client: SES Consulting / University of Calgary
Client Contact: Jeff Germaine (SES), Keith Altenhof (U of C)