Solar-MEC development program. Project 9103 third quarter progress report, March 1--May 31, 1978. [Desiccant wheel and regenerative heat exchange wheel performance]

Abstract

During the third quarter of the Solar-MEC™ program, work continued on developing the computer model simulating the desiccant wheel behavior (Task 1) and assessing the performance of the regenerative heat exchange wheel (Task 3). This report specifically presents the results obtained using the computer model as an analytical tool to evaluate design and operating conditions to optimize the wheel's performance. It also contains evaluations of two different available heat transfer matrixes: the currently used aluminum honeycomb and a new product, a potentially less-expensive, corrugated aluminum material. The mathematical modeling and diagnostic evaluations and ways of improving the component and machine performance were identified and are described for both tasks. In both areas, sufficient progress was made to draw several important conclusions. Of these, the two most important are-• Using the computer model, the observed experimental indications of the energy-saving influence of temperature-staging the heat input to regenerate the desiccant was confirmed. • It is possible to design practical regenerative heat exchangers, which will exhibit thermal effectiveness equal to or higher than the necessary 90% During the last quarter, a mathematical description of the behavior of other machine components, namely the models of the regenerative heat exchanger and the saturating pads to be included in the model, will be prepared. These will describe the overall machine performance. This work will be further supported by an experimental evaluation of these components. iii