Sustainable Thermal Systems Laboratory (STSL)

It was fun to present our progress on our project with my colleague Dr. Akanksha Menon, Ph.D., “Design and Integration of Thermochemical Energy Storage (TCES) into Buildings for Load Shedding/Shifting,” at the U.S. Department of Energy (DOE) Building Technologies Office Peer Review in Arlington, Virginia, Oct 21-24, 2024. Our poster was well received, leading to discussions with a variety of stake holders. A special bonus was to be presenting our progress along with Sustainable Thermal Systems Laboratory (STSL) alumni, Dr. Allison Mahvi at the University of Wisconsin-Madison, and Dr. Bachir El Fil who recently joined our faculty at Georgia Institute of Technology, both of whom were presenting their own project updates. Yet another source of pride was to see that Dr. Alex Rattner, another alumnus from Sustainable Thermal Systems Laboratory (STSL), now on the faculty at Penn State University, was one of the reviewers at this peer review program. As an educator, there is no better joy than to see your own students as your colleagues and also as your evaluators! #PeerReview #ThermoChemicalEnergyStorage #HeatPump #LoadShifting #Decarbonization

Our paper, “Enhancement of air-side heat transfer in crossflow heat exchangers using auto-fluttering reeds,” recently appeared in the Applied Thermal Engineering Journal. This study investigates the use of autofluttering reeds for the enhancement of air-side heat transfer. Heat transfer experiments were conducted on an air-cooled heat exchanger representative of those used in the process, HVAC and power plant industries equipped with a set of 1440 rectangular Mylar reeds installed in the air-side channels. Nusselt number and friction factor were measured for flow rates corresponding to air-side Reynolds numbers from 1200< Re < 3400. Heat transfer enhancement up to 60% was observed with a maximum friction factor penalty of 200%. Geometric optimization of the reeds and fin channels could yield additional heat transfer enhancement. This technique offers the possibility of decreasing the size of air-coupled heat exchangers used in a variety of industries. Read more in detail below. #heattransfer #air #enhancement Roland Crystal Srinivas Garimella George W. Woodruff School of Mechanical Engineering. https://lnkd.in/etu-2RUn

Our paper, “Investigation of a novel combined ab- and ad- sorption based thermal energy storage and upgrade system,” recently appeared in the Applied Thermal Engineering Journal. We have designed a sorption-based cycle that combines energy storage and energy upgrade for the purpose of long-term, low-grade heat storage. A transient model that simulates the charging, storage, and discharge phases was developed to model the underlying ab- and ad- sorption processes. In the representative application under consideration, this cycle couples absorption and adsorption to store this low-grade heat and discharge it at a temperature of 62°C. Discharge temperatures achieved in this work for such long-term energy storage are much higher than those reported in the literature using other storage systems. Long-term energy storage is a key component to decarbonization of building heating, and this cycle demonstrates energy storage densities from 71 to 185 kJ kg-1, depending on the operating conditions under consideration. Read more in detail below. #adsorption #absorption #energystorage Allannah Duffy Srinivas Garimella George W. Woodruff School of Mechanical Engineering https://lnkd.in/e_YKZpkD

Our paper, ‘Modeling steam generation in the free-falling zone in direct-chill casting of aluminum’, is now published in Applied Thermal Engineering! We have developed two coupled models, one of which simulates the solidification and cooling of a representative aluminum 28.8 ton ingot, modeling the transient conduction, aluminum solidification, and water evaporation from the cooling water to predict steam generation. The second model uses the results from the ingot model to describe an entire casting plant as it operates throughout the day. Annual water losses due to evaporation in aluminum casting plants are thereby quantified and validated using actual plant data. The findings show that over 1.5 billion kilograms of water could be saved every year by reclaiming steam from the process, pointing out avenues for significant improvements in energy and water conservation in such casting plants across the world. Read more in detail below! Thank you to Novelis for collaborating on this project with us. #HeatTransfer #Aluminum #WaterRecovery Jacob Tjards Srinivas Garimella George W. Woodruff School of Mechanical Engineering https://lnkd.in/gYGMmVSN

STSL PhD student Jacob Tjards and STSL alumnus Dr. Matthew Hughes attended the 18TH UK Heat Transfer Conference, (https://lnkd.in/gdZycF8c), September 9th – 11th at the University of Birmingham, UK. This conference, which is held every two years under the UK National Heat Transfer Committee, is a key platform for the local and international heat transfer community to convene, share ongoing research, and discuss the latest advancements in the field. Jacob Tjards’ presentation, “Radio Frequency Calcination of Gypsum for Sustainable Wallboard Production”, co-authored by Kristian Lockyear and Dr. Srinivas Garimella, presented experimental results and a model of electromagnetic heating of gypsum for the production of wallboard. The results were used to predict the reduction of energy consumption and emissions by replacing conventional gas-fired ovens with electromagnetic heating driven by electricity. This volumetric heating results in uniform calcination and particle size distribution, significant energy savings, and water savings in the subsequent processing. Matthew Hughes delivered a presentation entitled "The Broad Reach of Heat Pumps to Decarbonize Numerous End Uses," co-authored by Dr. Srinivas Garimella. Both presentations were well-received by the audience. #Congratulations #UKHTC2024 #HeatTransfer #EMHeating #HeatPumps #STSL

Join us in congratulating STSL Director, Prof. Srinivas Garimella, on being conferred the prestigious Georg Alefeld Memorial Award at the 17th International Sorption Heat Pump Conference (ISHPC 2024), held in Beijing, China from Sept 1st – 4th. This award is the highest recognition in the Sorption Heat Pump research community and acknowledges his outstanding and lifelong achievements in the field of sorption chillers, sorption heat pumps, and the elucidation of internal phase-change heat and mass transfer processes at the mini- and micro- scales to develop innovative sorption systems. Prof. Garimella was nominated by leading experts in the sorption research community, a testament to his lasting influence in the field. The Georg Alefeld Memorial Award was established to honor and commemorate Professor Georg Alefeld (1933-1995), a researcher, educator, and author who made outstanding contributions to the field of absorption heat pumping technologies.  The award is bestowed at every International Sorption Heat Pump Conference (at about a three-year interval) to an individual for outstanding scientific or engineering contributions and eminent achievements in the field of sorption heat pumping technology.  These contributions should yield a deeper insight into the underlying physical phenomena or should yield significant technological advances.  In addition to research, the Award Recipient should have made outstanding contributions to the field through teaching, design, or a combination of such activities. Previous winners of this prestigious award include Prof. Gershon Grossman (Technion-Israel Institute of Technology), Prof. Felix Ziegler (Technical University of Berlin), Prof. Takao Kashiwagi (Tokyo Institute of Technology), and Prof. Ruzhu Wang (Shanghai Jiao Tong University). George W. Woodruff School of Mechanical Engineering Georgia Tech College of Engineering #Congratulations #STSLGroup #ISHPC2024 #GeorgAlefed #Award #LifetimeAward 

STSL PhD students Kristian Lockyear and Allannah Duffy, along with STSL Director, Srinivas Garimella, attended the 17th International Sorption Heat Pump Conference (ISHPC 2024), September 1st – 5th, at Tsinghua University, Beijing, China. The conference focused on the latest progress in research and development of sorption heat pump technology. Kristian Lockyear presented two papers at the conference. His first paper, ‘An Assessment of Adsorbent-Ammonia Working Pairs and System Design Aspects for Adsorption Cooling and Refrigeration,’ co-authored by Dr. Srinivas Garimella, presented a literature review of experimental ammonia-based adsorption refrigeration systems. This paper received the Best Paper Award at the conference! Kristian also presented ‘A Numerical Study of Diffusion and Heat Transfer Limited Adsorption in a Radially Finned Tube Adsorbent Bed,’ co-authored by Allannah Duffy and Dr. Srinivas Garimella. Allannah presented ‘A Comparison of Closed and Open Thermochemical Storage Systems Integrated with Residential Heating,’ co-authored by Alper Saygin and Dr. Srinivas Garimella. Both presentations were well-received by the audience and initiated meaningful discussions on the topics of mass transfer and energy storage. Congratulations to all! #Congratulations #STSL #ISHPC2024 #Absorption #Adsorption #BestPaper

STSL Director Prof. Srinivas Garimella gave the first keynote speech at the 17th International Sorption Conference (ishpc2024.scimeeting.cn) in Beijing Sept 1-4, 2024. His talk was entitled “Did electrification kill Sorption Heat Pumps? Certainly Not!” He highlighted the broad reach of thermally driven absorption and adsorption heat pumps for space-conditioning, waste heat recovery, data center thermal management, thermal storage, water purification and conservation, and the cold chain. He pointed out the essential principle of such heat pumps as “sorption making it possible to make low grade thermal energy move uphill.” Prof. Garimella identified the pitfalls in viewing decarbonization solely as electrification, noting that the grid will continue to be dominated by fossil fuels for some time to come, and monolithic electrification of major end uses such as space heating and transportation would place undue demands on the electricity infrastructure and generation capacity, in turn leading to brownouts and perhaps even increased greenhouse gas emissions in the near term. With this recognition, he advised that a major fraction of human end uses is thermal, leading to significant exergy mismatches between source and end use, indicating that these end uses need not be satisfied by high grade electricity. Furthermore, he proposed that nuclear, solar thermal, waste heat, and biomass are all carbon neutral thermal energy sources amenable to sorption heat pumping and would go a long way in maximizing the available clean energy sources to facilitate the transition to a decarbonized energy infrastructure. Collocation and cascading of thermal energy use would further reduce the need for new prime energy input. He also noted that sorption heat pumping offers alternatives to compression-based heat pumping, which is facing increasingly significant challenges in the availability of safe and effective low-GWP synthetic refrigerants. Such a diversified strategy enabled by sorption heat pumping would alleviate the demands on electricity and electrochemical storage to balance out intermittency, also reducing the end-of-life disposal challenges on electrochemical storage materials. This positive message of a comprehensive strategy of reserving electricity for high grade end uses and supplementing the available options with sorption through collaboration rather than competition between electricity and thermal energy was received very well by the international audience and set the stage for the discussions that followed throughout the conference and beyond! #STSL #Congratulations #ISHPC2024 #Absorption #Adsorption #Sorption #Heatpump #Keynote #Plenary #Decarbonization #Electrification

Srinivas Garimella participated in the China Heat Pump Conference CHPC2024 (chpc2024.scimeeting.cn) in Shenzhen Aug 27-30, 2024, which was attended by 842 participants from academia and industry in 32 different counties. He gave the Plenary talk on "Heat Pumps: the Enablers of Essential Human Needs" in which he emphasized the role of heat pumps in decarbonizing not only space-conditioning, but also to facilitate many aspects of human existence. He discussed ways in which heat pumps are reducing carbon emissions in energy conversion, storage, recovery, and other critical end uses. Examples he provided included miniaturized absorption systems driven by renewable energy sources or waste heat, enhancement of the performance of commercial dryers, and the development of diurnal and seasonal thermal storage systems. Heat pumps driven by biomass, solar or waste heat for use in the cold chain to reduce food spoilage in developing countries with uncertain electricity infrastructure were also presented, as well as the use of heat pumps for simultaneous space-conditioning and water purification at the residential scale. These representative applications demonstrate the vast potential for innovations and impact of heat pumps for essential human needs such as food and water, clothing, shelter, and the environment. #STSL #Congratulations #CHPC2024