Advancing waste heat recovery solutions in industrial operations
Solex featured in February 2025 issue of Process Industry Informer
In the latest issue of Process Industry Informer, Scott Harris of Solex Thermal Science provides the case study of how Econotherm, a Solex company that specializes in industrial waste heat recovery, did more than just breathe new life into a U.S. power producer's 37-year-old Q-Dot heat pipe air pre-heater. Rather, it was able to improve the unit's performance to better match its built capacity, resulting in $1.5 million in annual savings due to a significant reduction in primary energy use.
Shuykill Energy Resources (SER), the U.S.-based independent power producer had been operating a Q-Dot heat pipe APH at its 80-MW St. Nicholas Electric Power Generation Station in Shenandoah, Pennsylvania, U.S. since 1987. Q-Dot built and installed dozens of large heat pipe APHs in power stations, refineries and chemical plants around the world during the 1980s and ’90s. Shuykill’s power station in Pennsylvania utilizes waste coal culm and silt to generate steam and electricity.
Over decades, the performance of the heat pipe APH at SER’s power station had degraded due to several known issues, including pipe corrosion, leakage, degradation of the organic working fluids. SER decided to replace the faulty heat pipes and address the leakage issues affecting the unit.
In the article for Process Industry Informer, Scott details how Econotherm's team was able to identify critical issues with the initial design that included an insufficient number of heat pipes being installed, limits on the maximum pipe working temperature (PWT) and more.
Some of the recommendation solutions included:
- Switching to an asymmetric fin design of the heat pipe to gain better control of the PWT.
- Utilizing multiple heat pipe types in a single unit to elevating configurations in the cold end of the unit, lowering configurations in the hot end and neutral configurations in the middle.
- Replacing the current welded approach with a screw-in collar.
The results?
- Reduction of 57.4 million BTU or 2.9 coal short tonnes per hour burned.
- Hourly savings of $173.23 USD based on price per tonne of $187.70/hour coal price based on MMBTU coal.
- Annual savings of $1.5 million.
- Reduction of 42,959 tonnes of carbon dioxide per annum.
- Substantial reduction in quench water consumed at the power station.
Read the full case study here.
This entry was last updated on 2025-2-28