At a Glance
Industrial Goods and Manufacturing
Industrial Energy Efficiency
Yiyan Cao worked on cooling water and compressed air system efficiency projects for an Owens Corning plant in China.
Owens Corning enlisted Yiyan Cao to help identify potential energy-saving opportunities at its composites plant located in Hangzhou, China. There, energy costs make up a high percentage of the plant's total costs, but the plant does not have a dedicated energy department. By collaborating with the engineering and maintenance departments, the goal for Cao was to identify potential projects so they could be included in the energy fund for 2016.
After analyzing the energy data of the plant and discussing her analysis with the engineering team, Cao and the team determined that the cooling water system and compressed air system should be the focus areas moving forward. Cao discovered that the cooling water system was excessively large for the capacity needed and did not respond sensitively to seasonal demand fluctuations. She recommended that a more sensitive pump arrangement should be implemented and two variable frequency drives could be added to achieve additional savings in winter. For the compressed air system, Cao found that the capacity of the compressors was much higher than the demand, so while the load was quite low, their power use was unnecessarily high. Changing one centrifugal compressor to a compressor with a variable frequency drive could increase the flexibility of the system and reduce energy consumption.
Over a seven-year lifetime, Cao’s recommendations could save $1.8 million in net operational costs. Cao presented her recommendations during Owens Corning’s Global Energy Meeting in August, and even before the end of her ten-week fellowship, the cooling water system retrofit was approved and scheduled for implementation.