Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Samuel Amoafo-Yeboah - Southern University and A&M College
Co-Author(s): Patrick Mensah, Southern University and A&M College, Baton Rouge, LA.Stephen Akwaboa, Southern University and A&M College, Baton Rouge, LA.
Domestic refrigerators are an integral part of modern day living and can be found in use in almost every home or office. Due to their worldwide and frequent usage, they tend to consume a lot of energy which is a major issue for consumers. Researchers have made efforts to develop solutions to reduce the electrical energy requirements while still maintaining desirable operating conditions, like stable cabin temperature within the refrigerators, in order to maintain food quality and allow food storage for long periods of time.Efforts to enhance efficiency of refrigerators while reducing their electricity demand has brought about promising research where Cold Thermal Energy Storage (CTES) is explored using Phase Change Materials (PCMs). PCMs utilize their high latent heat of fusion to store and release large amounts of energy by changing from solid to liquid and vice versa. The consensus is that the incorporation of PCMs with refrigerators will improve their efficiency while also providing energy during peak load demand thereby reducing electricity costs, however, different methods of incorporation are still being investigated to provide optimum refrigerator operation for different load demands.A high efficiency household refrigerator is to be developed with the aim of reducing peak electricity demand while also targeting a reduction in greenhouse gas emissions. Peak electricity demand reduction is to be achieved by the incorporation of a novel and advanced PCM evaporator with open-cell aluminum foams to enhance the heat transfer between the refrigerator cabin and PCM evaporator and reduce the time taken for the PCM to freeze and melt. The PCM evaporator will also have polyimide heater arrays on their surfaces for even heat distribution to facilitate defrosting of ice formed on evaporator coils which hinder optimum heat transfer to the PCM. Greenhouse gas emissions will be reduced using low Global Warming Potential refrigerants like HFO-1234ze or HFO-1234yf.This project will be focused on the development of a transient refrigeration model with high-fidelity computational fluid dynamics (CFD) modeling of the PCM evaporator with simulations of the effects of the evaporator coils, metal foams, heater arrays as well as simulations of air flow in the refrigerator compartment. PCM evaporator surface temperature distributions under various defrosting conditions will be developed to reduce defrosting control uncertainties. The above work will be done using the commercial fluid dynamics software ANSYS FLUENT. Subsequent work will include designing and optimization of the PCM evaporators using the already developed models and finally establishing a Computer Aided Design (CAD) layout of the refrigerator with design software SolidWorks.The proposed refrigerator is expected to improve overall operating efficiency by 20% by easing of peak electricity demand by 100% due to reduction of compressor on-off cycle to one cycle per day and reduction of greenhouse gas emissions by 30%.
Funder Acknowledgement(s): The authors are grateful for the financial support provided by the National Science Foundation, Grant Number HRD 1736136
Faculty Advisor: Dr. Stephen Akwaboa, firstname.lastname@example.org
Role: Modelling and Simulation