Students: Joe Noreika
Project: Enhancing Thermal Stratification in a Solar Thermal Storage Tank
Poster: Vertical (PDF) | Horizontal (PDF)
Institution: Lafayette College
Major: Mechanical Engineering
Advisor: Julia Nicodemus & Joshua Smith
Abstract
In this work, it is investigated how creating thermal stratification affects the rate of energy discharge from an immersed coil heat exchanger in a hot water storage tank. Within this experiment, there is an experimental apparatus consisting of a cylindrical NalgeneTM storage tank, a cylindrical baffle located within the tank, an immersed coil heat exchanger that is suspended in the annular region between the baffle and the tank wall, and a series of thermocouples which are located vertically along the centerline of the storage tank, along the baffle wall, and on the walls of the heat exchanger. Thermal stratification is first implemented in the experimental tank by creating an upper band consisting of 60% tank volume with hot, 61° C water, and by creating a colder, lower band consisting of 40% tank volume through mixing a colder, 20° C band, with an additional, hotter 61° C band. When analyzing pertinent metrics such as heat transfer rate to the immersed coil heat exchanger, it was concluded that a thermally stratified tank in this configuration leads to lower heat transfer rate when compared to an isothermal temperature tank. Being that the two dominant methods to increase heat transfer to an immersed heat exchanger are to increase the velocity of the storage fluid flowing across the heat exchanger and to improve thermal stratification in the storage tank, it was concluded that this stratification configuration resulted in an impedance of the negatively buoyant plumes circulating through the annular region of the tank, which created a significant amount of velocity degradation to the storage fluid flowing across the heat exchanger. As such, two further configurations are investigated: a smaller cold band in the lower region of the tank and a smaller temperature difference between the upper and lower band in the tank. Additionally, experiments were sought to be conducted without the implementation of the baffle in the tank to act as an experimental control.
About Joe Noreika
Joseph Noreika, Mechanical Engineering major and German minor from Milford, PA. I began my research into solar thermal storage tanks as an EXCEL Research Scholar in the Lafayette College Solar Lab under the guidance of my advisors, Professor Julia Nicodemus and Professor Joshua Smith. I have continued this research by pursuing an Honors Thesis, which is focused on enhancing thermal stratification in a solar thermal storage tank. In addition to my academics, I am also involved on Lafayette’s campus as a Head Resident Advisor in which I directly supervise 13 dormitory facilities and 12 Resident Advisors. In my free time I enjoy doing things such as playing tennis and skiing.