THERMAL ANALYSIS OF A SOLAR HOT WATER SYSTEM AND A STOCK TANK

During the cold winter months in the Midwestern States, a common problem that many livestock farmers face is to prevent the cattle drinking water, in a stock tank, from freezing. There are commercial water heating systems that consist of drinking fountains, submersible, or floating heaters. However, these units have typically high initial and operating costs. In this paper, we present the analysis and design of a low cost solar system that are made with tractor inner tubes and other readily available materials. Car and tractor inner tubes make good solar collectors because of their mechanical strength and thermophysical properties. The low cost solution reported here could also be used to address warm water supply and or space heating needs in developing countries. In this paper, the transient thermal response of wooden stock tanks with Fourier numbers around 0.01 is considered. Exact analytical solutions in the form of infinite series are used. The product solution of a cylinder and a plane wall is used to model the stock tank. Moreover, given the small Fourier number, a series of numerical experiments were performed to determine the number of terms that must be retained from the infinite series solutions to obtain accurate results. A theoretical model for the solar collector was also developed, and a series of physical experiments were performed to verify the theoretical models of the stock tank and the collector. The experimental results show that theoretical models, developed in this paper, predict the thermal behaviors of the collector and the stock tank well.