Improving Discharge Characteristics of Indirect Integral Collector Storage Systems with Multi-Element Storage
Desired performance of unpressurized integral collector storage systems hinges on the appropriate selection of storage volume and the immersed heat exchanger. This paper presents analytical results expressing the relation between storage volume, number of heat exchanger transfer units and temperature limited performance. For a system composed of a single storage element, the limiting behavior of a perfectly stratified storage element is shown to be superior to a fully-mixed storage element, consistent with more general analysis of thermal storage. Since, however, only the fully-mixed limit is readily obtainable in a physical system, the present paper also examines a division of the storage volume into separate compartments. This multi-element storage system shows significantly improved discharge characteristics as a result of improved elemental area utilization and temperature variation between elements, comparable in many cases to a single perfectly-stratified storage element. In addition, the multi-element system shows increased robustness with respect to variations in heat exchanger effectiveness and initial storage temperature.
K. Homan and A. M. Boies, "Improving Discharge Characteristics of Indirect Integral Collector Storage Systems with Multi-Element Storage," Proceedings of the 2004 International Solar Energy Conference (2004, Portland, OR), American Society of Mechanical Engineers (ASME), Jan 2004.
2004 International Solar Energy Conference (2004: July 11-14, Portland, OR)
Mechanical and Aerospace Engineering
Keywords and Phrases
Heat Exchanger; Storage Volume; Temperature Limited Performance; Thermal Storage; Heat storage devices
Article - Conference proceedings
© 2004 American Society of Mechanical Engineers (ASME), All rights reserved.