Investigation of Methods to Predict Thermal Stratification and Its Effect on Solar Energy System Performance.
Abstract
THIS REPORT DESCRIBES A STUDY TO IDENTIFY CHARACTERISTICS WHICH INDUCE THERMAL STRATIFICATION IN LIQUID THERMAL STORAGE, AND TO EVALUATE SOLAR ENERGY SYSTEM PERFORMANCE AS A FUNCTION OF THE DEGREE OF STRATIFICATION. It was determined that for efficient use of thermal stratification it was necessary to (1) introduce hot fluid at the top of the liquid storage tank and to add cold fluid at the bottom of the tank, (2) with a cylindrical tank, have a length/diameter ratio equal to or greater than 2.0, (3) use mathematical correlations to determine allowable fluid inlet velocities and temperatures, and (4) use storage tank material that has a thermal conductivity less than that of the storage fluid. The mathematical correlations described in this report allow stratification occurrence to be predicted and can be used to estimate the sharpness of the thermocline based on tank inlet and outlet conditions, fluid properties, and storage tank geometry. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1980
- Accession Number
- ADA086051
Entities
People
- B. J. Sliwinski
Organizations
- Construction Engineering Research Laboratory