Novel Temperature Control Technique for a Medicinal Herb Dryer System Powered by a Photovoltaic Array

Each plant has its own optimal drying temperature, especially for the medicinal herbs, because they are sensitive to heat. If the drying temperature becomes more than the optimal value, some chemical reactions will occur and influence the quality of the dried herb, such as color, taste, and aroma. While if the drying temperature becomes lower than the optimal value, the drying process will slow down, and consequently an expected degradation in the quality of the herb may occur, due to insects and fungi infestation which increase in moist conditions. This paper presents a new temperature control technique for a medicinal herb dryer system. The technique fixes the drying temperature of the medicinal herbs at 40^°C, even in cases of rapidly changing atmospheric conditions. The control of the dryer temperature is achieved through using the proportional integral (PI) controller. The designed dryer contains two systems, which are the thermal and the electrical systems. The thermal system is designed to heat the drying air by using solar energy and bio-gas fuel. Whereas the electrical system, which contains a photovoltaic (PV) modules and a battery, is designed to supply the different electrical loads of the dryer system. The control technique is investigated through simulation work by using MATLAB-SIMULINK. The simulation results indicate the high capability of the proposed technique in controlling the drying temperature, even in cases of rapidly changing atmospheric conditions.     

Removal of fluorescence and ultraviolet absorbance of dissolved organic matter in reclaimed water by solar light

Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter(DOM) was investigated in this study. Solar light significantly decreased the UV_(254) absorbance and fluorescence(FLU) intensity of reclaimed water.However, its effect on the dissolved organic carbon(DOC) value of reclaimed water was very limited. The decrease in the UV_(254) absorbance intensity and FLU excitation–emission matrix regional integration volume(FLU volume) of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV_(254) absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV_(254) absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV_(254) and FLU intensity were independent of light intensity. The peaks of the UV_(254) absorbance and FLU intensity with an apparent molecular weight(AMW) of 100 Da to 2000 Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change.     

太阳能-蓄电池供电系统在无人值守环境监测站的设计与实现

通过阐述如何设计和实现太阳能-蓄电池供电系统在无人值守环境自动监测站中的应用,推出了无人值守环境自动监测站建设的一体化能源解决方案。不仅提高了电源系统的可靠性同时交替的智能化给后级监测设备提供高质量、强大的不间断的电力支持!从根本上解决了现有电源系统设计匹配不合理,或因电源故障而造成监测数据的偏差或因电源故障造成设备损坏等事故。     

电子设备太阳辐射模拟试验分析与探讨

阐述了太阳辐射对电子产品的影响,介绍了试验的种类和进行选择的标准,重点分析了日辐射强度及其谱能分布、试验温度、湿度和风速等基本参数的确定依据和有关试验技术,并对太阳辐射试验模拟设备的研制提出设计要求,为我国自行研制非标环境试验设备提供了依据.     

曝气网联结的新型多层结构太阳光光催化反应器

设计了一种新型的浅槽型填充床光催化反应器，实验以亚甲基蓝作为模拟污染物，采用不锈钢曝气网，实现了高效的无动力曝气，在浅槽中交错安置挡板显著地改善了反应器中的流动状态。实验表明，以玻璃弹簧为载体的光催化剂可以较好的提高传质效果。反应器能充分利用太阳光中直射和散射的紫外光，在阴天也能有效地运行。