Study On Adsorption And Attenuation Characteristics Of Silica Gel In Silica Gel - Water Adsorption Refrigeration

The silica gel-water adsorption refrigeration system can be driven by the low temperature afterheat or waste heat, and can use the material for free from pollution to the environment as refrigerants. It is available for energy saving and environmental protection, and, coincides with the current trend for energy-environment sustainable development. Compared with absorption refrigeration system, silica gel-water adsorption system doesn’t need solution pump and distillation device, meanwhile, there are no some problems such as salt solution crystallization, the pollution of refrigerant, the metal corrosion and so on. Compared with vapor compression refrigeration system, silica gel-water system is simply controlled, saving energy, protecting environment, using low operating cost. Based on these advantages, silica gel-water adsorption system has wide development space for utilization in the solar energy and waste heat. So studying the silica gel-water adsorption system has the important significance.As the adsorbent in the adsorption refrigeration system, silica gel-water is the key part to provide the power for refrigeration cycle, and its adsorption performance could directly impact the performance of the whole refrigeration system. Therefore, the study of silica gel adsorption performance is an important part of the study about the technology and the theory for silica gel-water adsorption refrigeration system. Silica gel in the adsorption system constantly adsorbs and desorbs, and the adsorption ability would be gradually weaken. In adsorption systems, there are some factors existed to effect silica gel adsorption performance. After the analysis of the environment for silica gel adsorption, it is thought that running time, metal ions, pH of the environment for the adsorption bed, the dust impurities and the temperature of adsorption bed are the possible factors to influenced the adsorption performance of silica gel. According to the analysis many samples of silica gel were obtained, and using the experiment tests the influence of these factors for the silica gel adsorption performance.With the weight method and BET, it was measured the isothermal adsorbance, pore volume, pore diameter for silica gel. At the same time, using TGA it was got the content of silicon hydroxyl. Through the experimental. it was studied the influence of these possible factors on the adsorption performance of the silica gel, at the same time, with the method of comparison it was got the improvement for the adsorption performance of silica gel by acid soaking.With the analysis of the experiment data, the longer the adsorption system ran, the weaker the silica gel adsorption ability became; and in the close refrigeration environment, the dust impurities was one of the factors for the attenuation of silica gel adsorption performance; among the concentration range of the solution experiment used, Fe3+, Cu2+ and Al3+ existed in the adsorption bed, inhibited the silica gel adsorption performance, and Fe3+ had the biggest influence, Al3+ had the minimum influence; the higher the temperature of adsorption bed was, the weaker silica gel desorption performance was, and the better silica gel adsorption performance was. For silica gel by acid soaking the adsorption ability would be improved.