$10m funding for US heat pump projects
11th February 2024
USA: Four heat pump research projects aimed at reducing industrial greenhouse gas emissions are to receive a total of over $10m in funding from the US Department of Energy (DOE).
A total of 49 projects were pledged $171m by the DOE’s Industrial Efficiency and Decarbonisation Office (IEDO).
Aside from heat pumps, a further project selected is seeking to enhance the thermal conductivity and reduce the cost of carbon nanotube-based carbon fibres for use as heat exchanger fins.
CO₂ high temperature heat pump
Echogen Power Systems and its partners – Shell, Reaction Engines, Avery Dennison, Goodyear, Mars Corporation, TotalEnergies and Unilever – are to receive $3m to develop a pilot‐scale heat pump capable of heating air to over 300°C using an ambient temperature heat source.
The system will use a supercritical CO2 cycle driven by a low specific speed centrifugal compressor and a novel high temperature CO2-to-air heat exchanger. The supercritical CO2 cycle is said to enable a high COP and high process temperatures without the need for waste heat recovery, while the fluid’s high density and heat capacity enables reduction in heat exchanger size.
It is claimed that the technology could reduce life cycle carbon emissions by more than 90% and energy intensity by more than 50% relative to natural gas fired heaters.
PCM storage and wet compression
The University of Cincinnati, along with partners Trane Technologies, IAIRE and Phase Change Energy Solutions LLC are to receive $1,439,408 to develop a highly efficient industrial heat pump prototype using phase change material thermal energy storage, intermediate intercooling, and wet compression technology.
The wet compression technology will reduce the need for de-superheating of steam after compression. The technology is said to offer enhanced energy efficiency, high heat sink temperature, and the use of a low GWP refrigerant. It also enables waste heat utilisation and thermal energy demand response.
Simultaneous refrigeration and steam production
AtmosZero Inc, along with partners Colorado State University, Danfoss, International Flavors & Fragrances and Alliant Energy, will receive $3,197,493 for a project to develop a heat pump system capable of producing steam at temperatures up to 200°C while simultaneously providing cooling or refrigeration for industrial processes at less than 0°C.
The proposed heat pump is projected to achieve a Carnot efficiency of over 55% using a multi-stage cycle configuration, centrifugal compression with liquid injection, and internal heat recuperation.
Super condenser for water harvesting and waste heat recovery
A project to develop and demonstrate a super condenser that can effectively harness the waste heat from 125°C vapour, generated during the potato chip frying process, receives $3m for the University of Texas at Dallas and its partners ORNL, Radiator Coils, Trane Technologies and PepsiCo R&D.
The frying process is an energy intensive operation within the food industry. Current heat exchangers struggle to efficiently condense the waste heat due to the presence of oil droplets and volatile organic compounds. The proposed technology can recover and utilise the waste heat from the frying process to replace natural gas-burner heating technologies. This supplies process heat while also allowing for water recovery via oil separation generated from the frying operation. The project team will work to simulate, develop, manufacture, and demonstrate the high temperature heat pump system and heat exchanger system for waste heat recovery and water recycling that reduces carbon emissions by an estimated 80% and energy consumption by 70% for the frying process, along with lowering operating costs.
Carbon nanotube fibres for heat exchangers
The William Marsh Rice University and Dexmat Inc will receive $1.5m for a project to enhance the thermal conductivity and reduce the cost of carbon nanotube-based carbon fibres (CNTF). This material is seen as a high efficiency replacement for aluminium and copper heat exchanger fins.
The CNTF thermal conductivity enhancements are achieved through new processing approaches such as doping, annealing, and material selection. In addition, high-throughput processing will be combined with 3D textile manufacturing capabilities to demonstrate the effectiveness of heat exchange devices for industrial decarbonisation.
The DexMat-Rice research team has already developed — and recently multiplied production by 20x — Galvorn, a high-performing carbon nanomaterial offering an abundant, alternative to steel, copper and aluminium in a host of applications, including heat exchangers.
For this project, researchers will focus on increasing Galvorn fibre’s thermal conductivity to better-than-copper levels, while demonstrating textile-based CNT devices for potential use as heat exchanger fins in industrial applications, with a long-term target of replacing the aluminium or copper traditionally used with Galvorn.
