Experimental Study of a Solar Thermal Incubator Using a Phase-Change Material for Off-Grid Use

The aim of this study was to provide a simple, easy-to-use incubation system for small-scale rural poultry farmers far from the electricity grid. To this end, a naturally ventilated solar thermal incubator was built and experimentally tested. A U-shaped evacuated tube collector and a wooden crate holding 50 eggs were used to build the solar thermal incubator. Water was used as the heat transfer fluid, and an EPCM was integrated into the incubation chamber for operation at night or when the sun was hidden. The heat generated by the solar collector and stored in the heat transfer fluid is transported to the incubation chamber by thermosiphon to heat the chamber. Temperature and humidity probes powered by a solar panel were placed at various locations to monitor the thermo-hygrometric efficiency of the incubation system. The incubator, heated by natural convection, proved to function normally, and the incubation chamber was maintained throughout the incubation period within a temperature range of 35.53˚C to 39.53˚C and relative humidity averaging 49.4% to 68.5%. The experiment was carried out by introducing 30 eggs and the results of the experimental study showed that the incubator’s efficiency was 87%. The performance tests gave a fertility rate of 93% and a hatching rate of 93%, i.e. 28 fertile eggs and 26 hatched eggs, respectively.

Influence of TiCl_4 treatment on performance of dye-sensitized solar cell assembled with nano-TiO_2 coating deposited by vacuum cold spraying

Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crystalline TiO2 coating was deposited using a composite powder composed of polyethylene glycol (PEG) and 25 nm TiO2 particles by vacuum cold spraying (VCS) process. A commercial N-719 dye was used to adsorb on the surface of TiO2 coating to prepare TiO2 electrode, which was applied to assemble dye-sensitized solar cell (DSC). The cell performance was measured under simulated solar light at an intensity of 100 mW·cm-2. Results show that with an FTO substrate the DSC composed of a VCS TiO2 electrode untreated by TiCl4 gives a short-circuit current density of 13.1 mA·cm-2 and an open circuit voltage of 0.60 V corresponding to an overall conversion efficiency of 4.4%. It is found that after TiCl4 treatment to the VCS TiO2 electrode with an FTO substrate, the short circuit current density of the cell increases by 31%, the open-circuit voltage increases by 60 mV and a higher conversion yield of 6.5% was obtained. However, when an ITO substrate is used to deposit TiO2 coating by VCS, after TiCl4 treatment, the conversion efficiency of the assembled cell reduces slightly due to corrosion of the conducting layer on the ITO glass by TiCl4.

In-situ growth of a CdS window layer by vacuum thermal evaporation for CIGS thin film solar cell applications

Highly crystalline and transparent CdS films are grown by utilizing the vacuum thermal evaporation （VTE） method. The structural, surface morphological, and optical properties of the films are studied and compared with those prepared by chemical bath deposition （CBD）. It is found that the films deposited at a high substrate temperature （200 ℃） have a preferential orientation along （002） which is consistent with CBD-grown films. Absorption spectra reveal that the films are highly transparent and the optical band gap values are found to be in a range of 2.44 eV-2.56 eV. Culnl_xGaxSe2 （CIGS） solar cells with in-situ VTE-grown CdS films exhibit higher values of Voc together with smaller values of Jsc than those from CBD. Eventually the conversion efficiency and fill factor become slightly better than those from the CBD method. Our work suggests that the in-situ thermal evaporation method can be a competitive alternative to the CBD method, particularly in the physical- and vacuum-based CIGS technology.

Flat Panel Solar Thermoelectric System Size Optimisation at Different Vacuum Levels

A systematic experimental investigation to understand the effect of heat loss and the thermoelectric aspect ratio (cross sectional area and length) on a flat plate solar thermoelectric system performance was carried out. The investigation involved a series of experiments on systems with 4 different sizes of thermoelectric generators, and it was tested in 5 different vacuum levels during the steady-state. The detailed experimental investigation provided a substantial amount of data, which revealed that the system performance of both heat and electricity power were improved when the heat lost was minimised. The system’s performance strongly depended on the aspect ratio of the thermoelectric generators. This finding might have a significant impact on the cost of the system by saving the user’s and the manufacturer’s time in examining different TEGs with different aspect ratios in order to get the optimum size optimisation of the hybrid system, as well as reduce the manufacturing cost.

太阳能真空膜蒸馏和肥料汲取液正渗透处理反渗透浓水的节能性和经济性分析

针对太阳能真空膜蒸馏(Solar vacuum membrane distillation,SVMD)和肥料汲取液正渗透(Fertilizer draw forward osmosis,FDFO)系统处理反渗透(Reverse osmosis,RO)浓水的试验研究较多,而对其能耗和经济性分析的较少.通过对试验规模和工业规模条件下2种系统的膜通量、能耗和成本进行对比分析,结果表明,在试验规模条件下,将RO浓水浓缩4倍,无辅助热源SVMD系统的膜通量为2.46 kg/(m^(2)·h),比能耗为110.6 kWh/m^(3),单位水生产成本为96.6元/m^(3);有辅助热源SVMD系统的膜通量为3.75 kg/(m^(2)·h),比能耗为230.7 kWh/m^(3),单位产水成本为13.4元/m^(3);FDFO系统的膜通量为3.62 kg/(m^(2)·h),比能耗为20.44 kWh/m^(3),单位产水成本为26.8元/m^(3).在工业化规模条件下,设计产水量均为240 m^(3)/d时,SVMD系统比能耗为12.8 kWh/m^(3),单位产水成本为10.8元/m^(3);FDFO系统比能耗为12 kWh/m^(3),单位产水成本为9.38元/m^(3).可见生产规模越大,不同系统的产水成本越小,差别也越小.

太阳能真空集热管热损分析与试验研究

基于热平衡法提出了一种动态热平衡热损计算方法,并进行了验证,同时分析了环境温度、进口温度、流量对真空集热管热损的影响。结果表明,热损随着环境温度的降低、进口熔盐温度的升高和熔盐质量流量的降低而增大;当辐照强度在700 W/m2以上时,真空集热管获得的热量大于热损并能稳定工作,说明槽式光热电站在东南沿海等太阳能资源相对不足的地区有一定的适用性。

新型槽式太阳能真空吸热管设计方法及其光学性能研究

针对传统槽式太阳能集热系统工质运行温度受限,以及真空吸热管表面能流密度分布不均而引起的热应力过大等问题,文章在不改变聚光器结构的条件下,提出了一种新型的槽式太阳能真空吸热管的设计方法,通过减小金属内管直径、下移金属内管位置以及在金属内管上方加装双曲线型二次聚光器来提高太阳能聚光比,改善了金属吸热管表面能流密度分布。利用仿真计算方法研究了新型槽式太阳能真空吸热管的光学性能,结果表明:和传统槽式太阳能真空吸热管相比,该新型结构在仅损失1.88%光学效率的情况下将聚光比从62 kW/m^(2)提升至71 kW/m^(2);能流密度分布均匀度改善了55.05%,提升了聚光-吸热系统的整体性能。

内聚焦真空管集热器热泵系统实验研究及分析

本文提出了一种集热蒸发器为内聚焦真空管的直膨式太阳能热泵来提升系统性能,并搭建实验台获取实验数据,深入研究不同工况下系统的热力学性能。结果表明,太阳辐照强度对系统性能影响显著,当太阳辐照强度由400 W/m^(2)上升到800 W/m^(2)时,系统COP由4.18升至5.34,集热效率由0.94降至0.67,此时系统损由1175.33 W升高到2290.27 W,系统效率由16.82%下降到11.99%,此外循环水入水温度和环境温度对系统的性能影响远小于太阳辐照强度。集热蒸发器是系统从太阳辐射获取能量的部件,对它的设计优化将有助于改善系统性能。

一种适用于野外旅行的太阳能保温水杯设计

太阳能保温杯是一种利用太阳能进行加热和保温的便携式保温杯,特别适用于野外旅行等户外活动。该设计主要包含太阳能板、加热装置、保温杯体和锂电池4部分。太阳能板负责将太阳能转化为化学能,为电池提供能源。加热装置则利用电磁线圈产生热量,对保温杯内的水进行加热和保温。保温杯体采用高绝热材料制成,能有效阻止热量的散失,保证水温的稳定。此外,太阳能保温杯还具有便携性强、环保节能等优点。其不仅能满足野外旅行者的饮水需求,还能减少对环境的影响,是一种理想的户外用品。

大中型粮食烘干设备研究进展

随着农业科技的进步,粮食烘干设备在粮食加工过程中得到广泛应用。而关于粮食烘干的研究大多集中在工艺优化上,对于粮食烘干设备的研究较少,导致新型工艺技术难以应用,粮食烘干设备的进步受到制约。目前应用于粮食烘干的有热风、热泵、远红外、太阳能、真空、微波以及联合干燥设备,本文从工作原理、干燥效率、干后品质、能源消耗、发展趋势等方面对以上粮食干燥技术及其设备进行综述,介绍了节能环保、智能调控的新型干燥设备的研究现状,分析了各种大中型粮食烘干设备及技术存在的问题,并对粮食烘干设备的发展趋势提出建议,以期为粮食烘干产业健康发展提供参考。

全玻璃真空管型太阳能热水器在嘉兴地区节能量与减排量分析

为评估太阳能热水器对“双碳”战略的贡献,减少对化石燃料的依赖,推动能源结构的优化和转型升级,在嘉兴地区通过对全玻璃真空管型太阳能热水器在实际使用工况下进行热性能测试分析.试验结果表明:在实际使用工况下,环境温度和辐照量是影响太阳能热水器日有用得热量的重要因素;78和75管间距的年节能量分别为451.87 kWh/(m^(2)·a)、467.46 kWh/(m^(2)·a),CO_(2)年减排量分别为338.9 kg/(m^(2)·a)、350.6 kg/(m^(2)·a),经估算2021年太阳能光热利用CO_(2)减排量约占全国碳排放总量的12.6%.

A novel ice slurry producing system with vacuum freezing

A novel vacuum ice slurry producing system with jet-pumps was proposed to deal with the problems of high energy consumption and ice blockage.In this novel system,one steam driven by a jet-pump was used to create vacuum in a hermetic vessel where water was sprayed through a nozzle to produce ice slurry,while the other steam was used to provide enough cold energy to make the left vapor in the hermetic vessel condense.Mathematical models of this novel system were established and theoretical simulation on the performance characteristics was also implemented based on the MATLAB program.Results show that the novel system is feasible and practicable,and the system performance is affected by many factors,such as the temperature of the generators,condensing temperature,evaporation temperature,and the cooling load of the refrigerator sub-system.The findings are helpful to improve the performance of ice slurry producing system.

Study of the Solar Energy Drying Device and Its Application in Traditional Chinese Medicine in Drying

Background: We referred to nearly 40 years of development and application progress of solar dryer in China literature, especially its application in the field of Chinese herbal medicine drying. Objective: We explored the development direction of China’s development and application of solar dryers, especially focusing on its development and application in traditional Chinese medicine drying. Method: Five types of solar dryers including the greenhouse type solar dryer, the collector type solar dryer, the collector-greenhouse type hybrid solar dryer, the integrated solar dryer and the focusing type solar dryer accounted for the development and application of solar dryers up to 95% in China. The first three types of solar dryers are low temperature dryer (less than or equal to 70°C), while the latter two kinds of solar dryers are high temperature dryer (more than 70°C). In this paper, we respectively introduced and compared the structure, working principle, applications, advantages and disadvantages, and the research status of these five dryer. Results: The integrated solar dryer and the focusing type solar dryer belong to the high temperature dryer types are the future direction of development. Among them, the integrated solar dryer is relatively simple structure and has more promotion prospects. These two kinds of key drying device used in the dryer is the development direction of high efficient vacuum tube. On the other hand, because of their low cost, simple structure and the dry material requirements etc., the three types of low temperature dryers at low temperature for drying materials are also indispensable in the practical application. In contrast, the collector-greenhouse type hybrid solar dryer has more advantages, is the development direction of low temperature drying category. Conclusion: The collector tube which is the key element of the dryer was the core technology of solar dryer. Our country develops more successful of the all-glass vacuum solar thermal collectors and heat pipe-glass vacuum tube. Efficient vacuum tube collector technology is the future developed direction and is equally important to improve the quality of traditional Chinese medicine and dried.

Vacuum distillation refining of metallurgical grade silicon(Ⅰ)——Thermodynamics on removal of phosphorus from metallurgical grade silicon

The removal of impurity phosphorus from metallurgical grade silicon is one of the major problems on purification of metallurgical grade silicon for solar grade silicon preparation. The thermodynamics on vacuum refining process of the metallurgical grade silicon was studied via separation coefficient of impurity phosphorus in the metallurgical grade silicon and vapor-liquid equilibrium composition diagram of Si-P binary alloy at different temperatures. The behaviors of impurity phosphorus in the vacuum distillation process were examined. The results show that the vacuum distillation should be taken to obtain silicon with less than 10-7 P,and the impurity phosphorus is volatilized easily by vacuum distillation in thermodynamics. Phosphorus is distilled from the molten silicon and concentrated in vapor phase.

Vacuum distillation refining of metallurgical grade silicon(Ⅱ)——Kinetics on removal of phosphorus from metallurgical grade silicon

The kinetics on vacuum refining process of metallurgical grade silicon was studied using maximum evaporation rate,critical pressure and mean free path of phosphorus in the metallurgical grade silicon at different temperatures. The behaviors of impurity phosphorus in the vacuum distillation process were examined in detail. The results show that the fractional vacuum distillation should be taken to obtain silicon with high purity. Impurity phosphorus volatilize with the maximum evaporation rate of 1.150×105- 1.585×106 g/(cm2·min) in the temperature range of 1 073-2 173 K and the pressure below 2.1 Pa. Because the value of ωmax,P is at least 108 times of ωmax,Si,Si hardly evaporates and remains in the residual,which indicates that phosphorus can be removed from metallurgical grade silicon(MG-Si) completely.

Modeling and Simulation of a Bonding Process for Space Solar Cells

A bonding process for space solar cells implemented by an automated coating and bonding system was theoretically investigated for future parametric studies to achieve better bonding quality. First, the mechanical properties of silicone adhesive and the vacuum suction cup were experimentally analyzed. Based on the constitutive relationship of four parts in the bonding process, the dynamic bonding process was modeled systematically, and numerically simulated by a commercial finite element analysis code, Adina. The final bonding edge-alignment error and the thickness and uniformity of the adhesive layer were obtained from simulation and validated by experiments. A simulation platform was created for predicting the final bonding quality via adjusting bonding parameters when dimensions of the solar cells and adhesive were changed.

An Experimental Investigation of the Factors Which Affect on the Performance of a Single Basin Typical Double Slope Solar Still for Water Desalination

Solar energy is very useful in the process of desalination especially for areas that suffer from a lack of clean water resources. In recent years, many people have been using solar still. Therefore the raising of the productivity and efficiency of solar still represents the most important problems that need further research. The present work aims to study the effect of preheating the water entering to still and the effect of reducing pressure inside the still on the productivity of the solar still. Therefore in present work two identical single basin typical double slope solar stills of the inner basin dimensions for each still 2 m × 1 m × 0.08 m, have been designed and fabricated with mild steel plate. One of them is conventional solar still and the other is modified with flat plate collector and vacuum pump to study the effect of preheating and vacuum on the performance of solar still. The experimental measurements are made to enhance the solar still productivity by firstly preheating the water entering the still using flat plate collector and secondly by integrating the still basin with vacuum pump. The results show that preheating the water entering the still increases the water productivity by amount about 27.7% - 29.3%. The results also show that decreasing pressure inside the still using vacuum pump improves the solar still water productivety by amount about 21.8% - 23.9%.

Interface passivation engineering for hybrid perovskite solar cells

The allure of high efficiency and low-temperature solution-processed organic-inorganic hybrid perovskite solar cells(PSCs)are inspiring scientists to seek for its commercialization.Interface passivation engineering has become an effective way to further enhance the efficiency and stability of PSCs by defect passivation,reduces the charge recombination and ion migration initiation and hysteresis control,etc.Herein,we have summarized the effects and recent research progress of interface passivation engineering in PSCs.Interface passivation layers can be realized by using the solution and/or vacuum evaporation processes which are very adaptable to varied materials with different properties and fabrication processes for enhanced photovoltaic performance and stability.

Effect of CuI Anode Buffer Layer on the Growth of Polymers Thin Films and on the Performances of Organic Solar Cells

Organic photovoltaic cells using polymer belonging to the aniline-heteroaryl family as electron donor have been achieved by thermal evaporation. We show that the properties of the polymer film, morphology, molecule order and conductivity depend strongly on the bottom anode buffer layer. While cells without anode buffer layer or with MoO3 or CuI anode buffer layer have been probed, we show that CuI allows improving strongly the cells efficiency through an improvement of the morphology and conductivity of the polymer film. This shows that although it is necessary a good band matching at the interface, this is not sufficient, because the templating effect of CuI on the polymer film is primordial for photovoltaic cells improvement.

X-shape oligo(thiophene)s as donor materials for vacuum-deposited organic photovoltaic cells

The films of two x-shape oligo（thiophene）s, 3, 4-dibithienyl-2, 5-dithienylthiophene （7T） and 2, 5-dibithienyl-3, 4- ditrithienylthiophene （11T）, which are prepared by vacuum evaporation, have been investigated as novel electron donor layers in two-layer photovoltaic cells. UV-Vis absorptions show red-shifted and broadened absorptions of the vacuumevaporated films as compared with those of the corresponding solutions and spin-coating films, which is beneficial for photovoltaic properties. X-ray diffraction （XRD） and differential scanning calorimetry （DSC） measurements show that the vacuum-evaporated films are almost amorphous. Two-layer photovoltaic cells have been realized by the thermal evaporation of 7T and llT as donors and N, N′-bis（1-ethylpropyl）-3, 4：9,10-perylene bis（tetracarboxyl diimide） （EP- PTC） as an acceptor. An energy conversion efficiency （ECE） of 0.18% of the cell based on 7T with an irradiation of white light at 100 mw/cm^2 has been demonstrated by the measurements of current （I）- voltage （V） curves of the cells to be higher than the ECE of the reference system based on donor dihexylterthienyl （H3T） that is linear and without α, β linkage.