Stirling cycle heat pumps for industrial heat recovery
Heat pump based on the Stirling cycle able to use wide temperature sources will enable reuse of industrial heat.
The Regents of the University of California, Merced
Recipient
Merced, CA
Recipient Location
Senate District
27th
Assembly District
$78,599
Amount Spent
Active
Project Status
Project Update
A prototype system has been constructed and initial characterization has been completed. A comprehensive model of the system has been implemented. This model is based on an ideal thermodynamic treatment of the Stirling heat pump cycle, augmented with thermodynamic and kinetic analyses of the non-idealities associated with the system. Primary amongst these non-idealiteis are viscous loss associated with the liquid pistons and incomplete heat transfer in the active volumes and regenerator. A detailed analysis of the tradeoffs between system efficiency and capacity resulting from liquid piston design has been completed. The modeling framework allows for design calculations balancing system thermal power density and coefficient of performance.
The Issue
There are three primary challenges limiting heat pump usage in industrial heat recovery:
(1) Current vapor compression heat pumps are unable to provide heat at temperatures necessary for many industrial applications.
(2) The efficiency of high temperature heat pumps is too low to justify their implementation in many industrial contexts.
(3) Finally, the high capital cost of heat pumps makes them noncompetitive with traditional heating sources.
Project Innovation
The Recipient is developing a novel Stirling cycle with liquid piston technology that: alleviates temperature limits imposed by refrigerants experiencing phase change, improves heat transfer performance, and reduces construction complexity and cost.
Project Goals
Project Benefits
The project delivers a high-temperature industrial heat pump capable of upgrading waste heat to levels suitable for demanding industrial processes, addressing key limitations of conventional vapor compression systems. Using a Stirling cycle with liquid piston technology enables higher operating temperatures, improved efficiency, and reduced system complexity. These advancements could result in approximately 20 percent lower capital and operating costs compared to existing high-temperature heat pump solutions. The technology supports fuel switching from natural gas to electricity, resulting in meaningful reductions in greenhouse gas emissions and criteria air pollutants. By improving the economics and performance of industrial heat recovery, the project enhances the feasibility of decarbonizing hard-to-electrify sectors. The combination of cost savings, efficiency gains, and emissions reductions provides clear value to both industrial operators and the broader public.
Affordability
Potential for 20 percent lower capital and operational costs through implementing liquid pistons to simplify construction and reduce the cost of industrial heat pumps useful for waste heat recovery to high temperature.
Environmental Sustainability
This project is developing high temperature heat pump technology that can replace natural gas fired industrial heating processes, reduce greenhouse gas emissions and criteria air pollutants.
Key Project Members
James Palko
Match Partners
The Regents of the University of California, Merced
