Masters Theses

Date of Award

12-1983

Degree Type

Thesis

Degree Name

Master of Science

Major Professor

Fred Tompkins

Committee Members

Kenneth DeBusk & Luther Wilhelm

Abstract

Three types of suspended plate solar air heaters were installed on farms in Tennessee to supply heat for grain and crop drying. A wrap-around solar air heater was constructed on a row crop farm in West Tennessee and used to dry 210 m3 (6000 bu) of corn during Fall 1982 and 105 m3 (3000 bu) of wheat during Spring 1983. Three portable solar air heaters were installed on a row crop farm in Middle Tennessee and used to dry 800 m3 (23000 bu) of soybeans and 120 m3 (3500 bu) of corn during Fall 1982. A multipurpose solar barn was erected to provide supplemental heat for large hay bale drying, grain drying, and shop heating on a farm located in East Tennessee. The barn was used to dry 400 680-kg (1500-lbm) large round bales of alfalfa hay, 72 m3 (2050 bu) of wheat, and 350 m3 (10000 bu) of corn during 1982.

A microcomputer-based data acquisition system was fabricated to monitor the three solar air heater installations. Collector efficiency and the quantity of usable heat supplied by each of three types of heaters were determined. DEC PDP-11/01 microcomputers with associated peripheral equipment were mounted in inexpensive suitcases and used as unattended field units for collecting and storing data values of pertinent parameters. Data were retrieved by a host computer which could contact each field unit via telephone.

Results of the thermal analysis revealed that solar air heaters can successfully be used to provide a suitable air temperature rise for most periods of crop drying. The analysis further indicated that a suspended corrugated absorber plate provided an effective means of solar radiation interception. The heaters operated with average efficiencies in the range of 50 to 70 percent.

Results of the economic analysis were computed with combinations of various interest and fuel inflation rates. The analysis indicated that the wrap-around solar air heater, as used on the test site, had an annual savings range of -$250 to -$489. The negative savings, or cost, resulted from low annual use of the heater. The portable solar air heaters had an annual savings range of $574 to -$195. The multipurpose solar barn had an annual savings range of $2015 to -$468.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Included in

Engineering Commons

Share

COinS