Study On Thermal Performance And Energy Storage Application Of Salt-Gradient Solar Pond

With the booming of economy and industry, and desiring for the energy sources, solar energy has been widely entering in people's view. Solar pond as a simple technological,economical suitable, efficient and non-pollutional solar collector has received a high attention in our country. The details of research subject includes the influence factors on the performance of solar pond; the preparation of solar pond, the solar pond incorporated with heating exchange system of the roof and the ground, applied to thermoelectric convertion. All of the main work summaried as follows:The industrial Sodium chloride used as the working medium to compound saline solution to study the number of the solar pond layers of non-convetion zone effects on the performance of the solar pond. The results showed that: with the increment of solar pond layers of non-convection zone, the average salinity and buoyancy is decreased, which is more helpful to turbidity reducing; the stability of salt gradient layers is enhanced, which can improve the heat storage property; the average salinity of non-convection zone is decreased, which can boost the heat absorption capacity.The NaCl, MgCl₂, MgSO₄ and imitational sea water?NaCl:MgCl₂:MgSO₄?8:1:1? are used as working mediums to study different kinds of working mediums effecting on the solar pond performance. The results showed that the higher molecular weight, the greater solubility of the salt and the bigger salt solution density, the more beneficial to salt gradient layer stability;The smaller heat capacity, the more beneficial to heating up of the solar pond, the better to decalescence performance; The phase change of salt hydrate is no longer occurred after which is dissolved into water, so the enthalpy of salt hydrate has little influence on thermal performance of the solar pond.The effect of different inorganic bottom materials on the properties of solar pond was studied. NaCl was used as working medium, adding the haycite, clinker, the mixture of haycite and clinker as the inorganic base materials, respectively. The results showed that: The decalescence performance of solar pond are inluenced by surface roughness and blackness of inorganic materials, but which have a little influence on the heat storage property; The inorganic bottom materials can decrease disturbance of the external environment to improve stability of the solar pond; the more the pore of inorganic bottom materials, In the earlier stage of the solar pond, the more benificial to turbidity decreasing, but the function of them weaken increasingly with the surface being covered.The salt-gradient solar pond which has excellent stability and thermal performance isfabricated and applicated into the temperature adjustment systems of building roof and ground.The results showed that: the temperature of experimental group is highter about 2.8? than the matched group when the ground heating system is running; while the temperature of experimental group is highter about 1.6? than the matched when the roof heating system is running, so the performance of ground temperature adjustment is better; the temperature of experimental group is lower about 2.4 ? than matched group when the roof refrigerating system is running. So the solar pond can be preliminarily ascertained to be applied into building temperature adjustment system.A simple temperature difference power generation device is designed, the principle of power generation device is explained, which is connected simplely with solar pond, the results showed that the connecting number of temperature difference power generation pieces is 5. The biggest output voltage of the device is 5.17 V, on the condition of optimal serial number of temperature difference power generation pieces, the biggest output voltage is 5.17 V, the required temperature difference value corresponding is 25 ?; The biggest output current is5.17 V, the required temperature difference value is 40?. So the objective of thermoelectric conversion of the solar pond energy storage.can be come true...