Purdue University is leading a research project that aims to significantly reduce energy use and greenhouse gas emissions in large-scale manufacturing industries. The project, funded by the U.S. Department of Energy, will develop novel high-temperature heat pump (HTHP) technology that can achieve temperatures up to 200 degrees Celsius or 392 degrees Fahrenheit. This technology can be integrated into multiple industrial applications to help decarbonize U.S. industry.
What are high-temperature heat pumps?
HTHPs are devices that harvest low-grade heat using a heat-absorbing refrigerant to compress it and deliver high-temperature heat for use in manufacturing processes. HTHPs can provide heating, cooling, and dehumidification simultaneously, and can also recover waste heat from industrial processes and use it as a heat source. HTHPs can improve the energy efficiency and environmental performance of industries such as chemicals, pharmaceuticals, paper, and food, among others.
Why are high-temperature heat pumps important?
According to the U.S. Energy Information Administration, in 2018, production of chemicals, paper, and food accounted for 54%, or 10.5 quadrillion, of the 19.44 quadrillion Btu used by all U.S. manufacturers. A Btu, or British thermal unit, is a measure of the heat content of fuels or energy sources. By comparison, in 2021, all U.S. homes used just 5.04 quadrillion Btu, or about 25% of total industrial use. Cutting electricity usage up to 50% in these large-scale energy-consuming industries would greatly reduce costs and environmental impacts.
The DOE’s Industrial Efficiency and Decarbonization Office, which established a roadmap to industrial decarbonization, this summer awarded $135 million in funding for 40 projects that will reduce the industrial carbon footprint toward a net-zero emissions economy by 2050. Purdue University’s project is one of them, and it has received $3 million in funding.
How will Purdue University’s project achieve its goals?
Purdue University’s project is led by Davide Ziviani, assistant professor of mechanical engineering and associate director of the university’s Center for High Performance Buildings. The project involves industrial partners who have a major stake in the mission of decarbonizing the U.S. industrial sector: Trane Technologies, the Shrieve Chemical Co., the Convergent Science engineering software company, GTI Energy and Chemours Co., a chemical research firm. Other collaborators include Oak Ridge National Laboratory and the National Institute of Standards and Technology, which will support advanced manufacturing and working fluid characterizations, respectively.
The project will last for three years, and it will focus on developing a new type of compressor for HTHPs – an internally cooled screw compressor – which operates using two intermeshing helical rotors, known as screws, to compress the refrigerant gas for high-temperature heat delivery. “The compressor is the heart that makes the system work. Our solution is an integration of the compressor within the system and its cooling that improves efficiency but also has reliability for long-term operation,” Ziviani says.
The project will also explore new working fluids for HTHPs, such as hydrofluoroolefins (HFOs), which have low global warming potential and high thermal stability. The project will use computational fluid dynamics (CFD) simulations and experimental testing to optimize the design and performance of the HTHP system and its components. The project will also demonstrate the HTHP system in a real industrial setting and evaluate its economic and environmental benefits.
What are the expected outcomes and impacts of the project?
The project aims to achieve the following outcomes and impacts:
- A novel HTHP system with an internally cooled screw compressor that can operate at temperatures up to 200 degrees Celsius or 392 degrees Fahrenheit.
- A comprehensive database of thermophysical and transport properties of new working fluids for HTHPs, such as HFOs.
- A validated CFD model of the HTHP system and its components, which can be used for design optimization and performance prediction.
- A prototype HTHP system that can be integrated into various industrial applications, such as drying, distillation, evaporation, and sterilization.
- A demonstration of the HTHP system in a real industrial setting, such as a food processing plant, and an assessment of its energy savings, cost-effectiveness, and greenhouse gas emissions reduction.
The project hopes to contribute to the advancement of HTHP technology and its adoption in the U.S. industrial sector, which could lead to significant energy efficiency improvements and carbon footprint reductions. The project also hopes to inspire more research and innovation in the field of HTHPs and other clean energy technologies.
