|Budget Amount *help
¥6,200,000 (Direct Cost : ¥6,200,000)
Fiscal Year 1993 : ¥2,800,000 (Direct Cost : ¥2,800,000)
Fiscal Year 1992 : ¥3,400,000 (Direct Cost : ¥3,400,000)
In this research, a annual heat storage in the earth ground is treated. Asystem of heat storage is composed of closed type thermal well, and assumed to be used as heat source of heat pump. To analyze heat storage process of those system, a mathematical model is presented in this study, in which heat transfer in the earth ground is modeled as simultaneous heat and moisture transfer. By applying the model, effects of moisture in soil, level of water table and precipitation on the earth surface can be analyzed. The model are used to analyze experimental results mentioned bellows and validity of the model are discussed.
A experimental study was perfomed over 2 years. The system is composed of a thermal well, heat pump and a water circulation system. Under sinusoidal heat supply (positive during summer and negative during winter) to the well, water temperature in the well were measured over two years, and distributions of temperature and moisture potential in the earth ground were measured. Those measured results are compared with calculated results obtained by solving the mathematical model. They show very good agreement between them. Design method using the mathematical model presented, are shown.
Of freezing and melting process in the earth ground, a mathematical model is presented. And numerical calculations are shown. In addition to those, a method of optimum control of heat storage is presented, treated as stochastic process of heat storage process.