A numerical study on the effect of the heat sink as condenser on the performance of passive solar still
A theoretical work is presented to study the effect of using heat sink as condenser on the performance of passive solar still. Single acting solar still facing the south with pure saline water is used in this work. During this study, a heat sink of a tip fin is used as a condenser instead of vertical glass plate of the conventional passive solar still. The theoretical model of the energy balance equations for each component: the basin water, the cover glass, the basin base and the condenser of the solar still were presented. The theoretical model was numerically solved by using MATLAB to assess the temperatures of the various components, the desalinated water productivity, and the system performance. To examine the validity of the model, the numerical results were compared with the available experimental data in the literature. It is found that the numerical results were in close agreement with the experimental data for both the components' temperatures and output productivity. A comparison of the performance of the studied solar still and the conventional solar still is presented. The results showed that the maximum productivity and efficiency of the solar still with heat sink as condenser are 0.8756 kg/m2.hr and 61.72 %, respectively comparing with 0.4305 kg/m2.hr and 30.35% for conventional solar still at the same conditions. Additionally, heat sink as condenser increases also the performance of the solar still compared to conventional solar still.
Investigation on the effects of heat capacity on the theoretical analysis of single slope passive solar still
Surfaces used for evaporation and condensation play a vital role in the performance of single slope passive solar still. To reach the optimum design, many experimental and numerical studies have been done on different configurations of solar stills by examining the effect of climatic, operational and design parameters of solar still components on its performance. Majority of those investigations have not taken into account the heat capacity of the basin and glass cover for simplification of mathematical model. The heat transfer and thermal losses from the components of a solar still are influenced by the thermal properties like heat capacity, absorptance and thermal conductivity of its components. In this observation, an attempt has been made to develop a mathematical model, which is used to find the effect of heat capacity of the basin and glass cover on the performance and exergy destruction of single slope passive solar still.
The Influence of the Supervision of Psychotherapy upon being Therapeutic: II: Modes of Influence of the Supervisory Relationship *
Through supervision, the student develops those innate personal characteristics which are highly important in being therapeutic. In making conscious use of “reality identification” by the student with his teacher, we must take care to avoid certain pitfalls. What is not wanted is transference identification. To help avoid this, we must select appropriate teachers as supervisors. The student should also have more than one supervisor, as this tends to protect against the development of over-idealization on the part of the student, and of omnipotence on the part of the teacher. Personal characteristics of both students and supervisors are extremely important. A good supervisory experience is the most likely vehicle for developing those qualities in the student which will, in time, lead him to function most therapeutically.