Waste heat is closer than you think
Jun 17, 2022
Integrating an industrial heat pump application into a flue gas condensing plant is an efficient way to capture the value of waste heat streams. Existing power plants already have all the necessary connections and systems in place to allow easy use of this most common waste stream in energy production.
District heating suppliers are increasingly looking for ways to decrease CO2 emissions by reducing fossil fuel burning. This is typically done by replacing fossil fuels with more renewable biomasses and smaller decentralized sources of available waste heat streams. It has become popular and economically beneficial to make the most of waste heat streams using industrial heat pump applications.
What is waste heat?
Waste heat can be defined as any stream that leaves a controllable process. The most typical waste heat sources close to cities’ district heating water networks are warm condensates from process industries, municipal wastewater treatment plant effluents, data center cooling waterflows and moisture containing gas exhaust from processes. Waste heat can be captured by cooling these flows further when they are exiting the process as an end pipe solution with no effect on the overall process.
Flue gas condensing plants have significantly increased overall plant efficiencies
In recent decades, flue gas condensing plants have already increased the overall plant efficiencies of the conventional combustion process from 90 to 115 percent, providing significant environmental and economic benefits. Flue gas condensing plants have minimized waste heat generated by the combustion process with a district heating water return temperature of about 42 to 55 °C. Even with such good progress, one of the biggest waste heat sources in the city area remains the stack of a district heating power plant burning conventional fuels.
In recent decades, flue gas condensing plants have increased overall efficiencies of conventional combustion process from 90 to 115 percent.
Industrial heat pump applications increase heat recovery from flue gas condensing plants
A flue gas condensing plant can easily be upgraded with an industrial heat pump application to capture free waste heat. This improves the plant’s overall efficiency and minimizes exhaust gas loss from the stack. Existing power plants already have all the necessary connections and systems to allow easy use of this most common waste stream in energy production.
Text Mikko Paavola and Marjaana Lehtinen
Photos Klaffi Tuotannot
Related articles
