18. Investigation of Heat Storage Performance of a Solar Pond with Potassium Chloride

This chapter concerns an experimental investigation of heat storage performance of a solar pond saturated with potassium chloride. The solar pond consists of potassium chloride water zones. The heat storage zone (HSZ) is formed as saturated brine with potassium chloride to collect and storage reaching the solar radiation. The gradient zone (GZ) is called non-convective zone (NCZ) with various density layers prepared with potassium chloride brine decreasing from HSZ to upper convective zone (UCZ). The layers consist of five different concentrations with a thickness of 10 cm each. These layers form a brine gradient to prevent heat transfer by convection from HSZ and brine layers to UCZ. The brine gradient layers act as an insulator between HSZ and UCZ. UCZ is a clean water layer. Solar radiation is especially absorbed by saturated brine zone through UCZ and NCZ. The mass capacity of the HSZ is approximately 430 kg. The measurements of the temperatures and densities of the layers are obtained by using thermocouples and hydrometers from August to November. The exergy efficiency of saturated potassium chloride brine is defined in terms of heat storage capacity of saturated brine and average representative solar energy. As a result, the maximum and minimum exergy efficiencies of the HSZ are obtained as 25.33 % in August and 9.77 % in November, respectively.