Hydrogen-Blended Combustion Technology in Gas Turbine

[Introduction] As the country has set ambitious targets in carbon peaking and carbon neutrality for the energy sector, there is a growing demand for technology improvements of low-carbon emission for power station gas turbines. It is urgent to explore the path of the key technology for this goal in China. The lean premixed combustion technology of gas turbine can make the air volume for combustion deviate from the theoretical air volume, which is the main technology to reduce NOx emission at present. At the same time, by mixing hydrogen in natural gas when combusting, it can effectively reduce the consumption of fossil energy and reduce carbon emissions. [Method] In this paper, a one-dimensional premixed free propagation flame model was established by Chemkin-Pro software, and the effects of different equivalent ratios, initial temperatures, initial pressures, and hydrogen-blended ratios on combustion temperatures, combustion rates, pollutant generation concentration, combustion free radicals, and chain reactions were compared. The temperature distribution, fuel component change and emission characteristics of combustion process were simulated. [Result] It is found that by mixing hydrogen in natural gas when combusting, fossil energy consumption and carbon emissions can be effectively reduced. However, the higher flame temperature brought by the lean premixed combustion of natural gas mixed with hydrogen will promote the generation of NOx, and at the same time, more CO will be produced at a lower equivalent ratio. [Conclusion] Based on the above research, the key data of hydrogen-blended combustion are obtained, which lays a foundation for the completion of hydrogen-blended combustion technology route

Intensity Distribution Design for Laser-Induced Thermal Loading Based on Numerical Simulation

To accomplish laser-induced thermal loading simulation tests for pistons,the Gaussian beam was modulated into multi-circular beam with specific intensity distribution.A reverse method was proposed to design the intensity distribution for the laser-induced thermal loading based on finite element(FE) analysis.Firstly,the FE model is improved by alternating parameters of boundary conditions and thermal-physical properties of piston material in a reasonable range,therefore it can simulate the experimental resul..

单晶冰动态力学行为的分子动力学模拟

本文通过分子动力学方法研究了高应变率均匀压缩加载情况,单晶冰在不同初始温度条件下的动态力学响应行为。研究表明,对于单晶冰而言,其强度随初始温度的降低而升高。值得注意的是,在不同温度条件下,单晶冰的形变机制发生了变化。温度相对较高时,主要发生固-液相变,即压缩过程中出现局部融化,而后固液界面向内部推移;然而,当降低初始温度至一定值后,则相变机制由固-液相变转变为固-固相变,即压缩过程中,出现了不同固态相之间的转化。对于高温条件下,发生相变后,应力随应变的增加而缓慢增加;低温条件下,相变阶段应力幅值会有急剧下降的过程。这两种不同的形变机制可以对吴先前等人(Xianqian Wu et al. Cold Reg Sci Technol)的实验结果给出一定解释。他们发现冰的强度在不同温度条件下会出现阶段线性的变化:当温度高于-125oC,峰值应力(强度)随温度的降低而升高;当继续降低温度至-173oC时,则峰值应力基本维持不变。其原因可能是相对较高温度时,主要出现局部裂纹扩展、局部融化导致破坏,冰的强度与传统材料一致,随温度的降低而增加。当温度降低至一定值后,则压缩过程中可能会发生冰的固相之间的转化,则峰值应力不仅与温度相关,还受相变行为的影响,从而导致冰的峰值应力在一定温度范围内基本维持不变

Numerical Simulation of Lateral Ventilation for Moisture Retention of Grain Storage at Different Ventilation Temperatures

In order to ensure the quality of rice in long-term storage, it is of great significance to simulate and analyze the horizontal cooling and water-retaining ventilation under the conditions of same humidity and different ventilation temperatures.Based on the heat and mass transfer theory of hygroscopic porous media,this study applied the existing mathematical model of heat and moisture transfer of grain reactor, and analyzed the change rule of different air inlet temperature on the temperature and moisture of grain storage barn under the same humidity with the numerical simulation method.The results showed that when the initial temperature of the grain reactor was 25 ℃ and the air inlet temperature was 17 ℃, the cooling rate of the grain reactor was the fastest and the moisture absorption and desorption of grain reached the balance first,and the water retention effect inside the grain reactor was the best.When coupling heat and moisture transfer was carried out between the grain layer 0.4 m away from the air inlet and the air inlet at different temperatures, the grain layer temperature and moisture decreased in the same trend.The higher the air inlet temperature was, the more obvious the moisture loss was.The lower the inlet air temperature was, the greater the drop in grain stack temperature was.As the distance between the grain layer and the air inlet increased,the cooling effect of the grain layer became worse.When the ventilation temperature was 19 ℃, the temperature of the grain layer 26.2 m away from the air outlet almost kept the initial temperature of the granary unchanged, so the cooling effect cannot be achieved

Study on Si doped with supersaturated Ti induced by continuous wave Nd∶ YAG laser

为了在硅中掺入过饱和的过渡金属杂质,采用自行设计的线形大功率Nd∶YAG激光辐照表面溅射钛的硅片,对辐照后样品进行了俄歇电子能谱测试,利用2维热力学模型,对连续激光扫描的过程进行了热力学模拟。结果表明,硅中的钛掺杂浓度远高于钛在硅中的固溶度,钛的最高浓度在表面下方一定距离处;硅片中的最高温度并不在硅的表面,温度分布导致了钛的分布不在表面;模拟结果与实验结果吻合得较好。线形连续激光能够通过对材料表面扫描辐照的方式进行加工,实现过饱和掺杂。In order to prepare Si with supersaturated transition metal,a self-designed linear high power Nd∶ YAG continuous wave laser was used to irradiate a Si wafer sputtered a layer of Ti. Then the sample was measured by Auger electron spectroscopy and the thermal field was simulated based on the 2-D thermodynamic model. The experimental results indicate that the concentration of Ti in Si is much larger than the solid solubility of Ti in Si and the position of the maximum concentration of the Ti is below the surface of the sample. The maximum temperature is not at the top surface of the sample. Temperature distribution directly leads to the maximum temperature of Si wafer below the top surface of the sample. The simulation results are in good agreement with the experiment results. The saturated transition metal can be supersaturated by irradiating and scanning the material surface with a linear continuous wave laser.国家自然科学基金资助项目(61076056

Research on coal-geothermal collaborative exploration system in deep mines

Under the trend of deep mining of coal resources, the problem of high temperature heat damage in mines is becoming increasingly serious, the heat source that causes high temperature heat damage in mines is actually sustainably used geothermal energy, extracting and utilizing geothermal energy from deep mines while mining coal is an innovative way to build green mines and reduce mine carbon dioxide emission. This paper summarizes the current situation of deep mineral and geothermal energy collaborative exploration at China and abroad, analyzes the feasibility in terms of processes and key equipment and finally proposes a system of coal-geothermal collaborative exploration. The system adopts closed cycle mode, including ground heat utilization system and underground extracting system, drilling horizontal holes and installing coaxial casing heat exchangers at the coal to extract the heat, and utilization of the extracted low-grade geothermal energy through the heat pump on ground. Adhering to the principle of “mining heat first and then mining” in terms of time and space coordination, the thermal mining face is divided in front of the mining work in advance, and two modes of sequential and alternating thermal mining are proposed to ensure that the thermal mining process does not interfere with the coal mining process. Analyzed key technologies including spatial collaborative design, coal seam drilling, efficient heat extraction, and intelligent monitoring and control. Conducted underground spatial collaborative design for coal mining and geothermal energy extraction, proposed a coaxial casing heat exchanger layout process based on coal seam water injection. Multiple combinations of quick assembly coaxial casing heat exchangers can be used to achieve efficient heat extraction. Building an intelligent monitoring and control platform and proposed relevant optimization models, building a heat extraction calculation model and propose an intelligent control heat extraction method. Simplify the heat transfer process of coal formations, construct a heat transfer model for heat extraction from coal to calculate and evaluate the heat capacity of the mining face based on its actual situation and the outlet airflow parameters. According to the heat transfer model, the initial temperature of coal, the coal transportation volume, and the outlet air flow temperature through mining face are the key parameters that determine the heat extraction from the coal. The heat extraction is the maximum when the moisture content of the air flow of the working face remains unchanged and the equivalent temperature of the air flow at the outlet of the working face is not higher than 28 ℃. The application of this system will converting heat damage of deep mine to useful resources, which not only solves the problem of heat damage of coal mining, but also realizes the comprehensive utilization of geothermal energy in deep mine

Battery pack thermal management based on thermo electric cooling and phase change material heat preservation

为提高户外基站备用电池组的工作性能、延长使用寿命，需要进行冷却和保温。将半导体制冷(TEC)与相变材料(PCM)保温相结合，对基站用48 V铅酸电池组进行热管理。模拟分析TEC的布置、制冷功率和环境温度对冷却保温效果的影响。TEC设置在电池组前后两侧、制冷功率为170 W时，可降低电池的温度、提高冷却阶段电池组温度场的一致性、延长保温时间。电池组经过连续的冷却保温过程，仍处于最佳工作温度范围，电池充放电时的最高温度可得到抑制

Investigation on high-quality, healthy, intelligent lightings based on light-emitting diodes

中国半导体照明行业面临着前所未有的发展变革，新一轮科技革命与产业变革正创造着历史性的新机遇。产业前沿迅速延伸，技术突破远超预期，创新应用和超越照明已经成为新的增长点，半导体照明行业已经迎来跨界大合作的新时代。 我国半导体照明行业正处于一个三重动力共同推动发展的关键时期，即基于LED（Light-EmittingDiode，发光二极管）可控性的数字化发展、基于生物机理研究和健康需求的光品质提升、以及有别于通用照明的创新应用的拓展。这三重动力共同推动了半导体照明和新一代信息技术的融合，推动了按需照明与创新应用的发展。 随着半导体照明及其控制技术的不断进步，人们已经从单纯对高光效的追求逐步转为对...The semiconductor lighting industry in China has been undergoing an unprecedented revolution in technologies, creating abundant opportunities. Technology breakthrough is far more than expected, the industry leading edge extends rapidly, and trans-boundary lighting and innovative applications have become long-term growth momentums. The semiconductor lighting has ushered in a new era of trans-bounda...学位：工学博士院系专业：物理与机电工程学院_电子科学与技术学号：3332014015429

Effects of heating rate on fast pyrolysis of cut filler of cigarette

为考察升温速率对卷烟烟丝快速热解行为的影响,采用热重-质谱联用技术对卷烟烟丝在不同升温速率(200 K·min~(-1)~800 K·min~(-1))下的热解特性进行研究,并建立了不同升温速率下卷烟烟丝的快速热解动力学模型。结果表明:(1)随着升温速率的升高,烟丝各主要成分热分解温度区间的叠加程度、热解速率以及释放特性指数均呈递增趋势,且有不同程度的热滞后现象。(2)引入升温速率校正因子的动力学模型能够克服热滞后所引起的动力学参数偏差,可以更好地预测不同升温速率下卷烟烟丝的快速热解行为。(3)高升温速率下,热解烟气产物中质荷比(m/z)为56(丙烯醛)、79(吡啶)、84(烟碱)、94(苯酚)和117(吲哚)的化合物释放量减小。在高升温速率下卷烟烟丝的快速热解特性与卷烟燃烧的真实状态更为接近,建立的卷烟燃烧数学模型更加准确。In order to study the effects of heating rate on fast pyrolysis of cut filler of cigarette, TGA(Thermogravimetric Analyzer) combined with QMS(Quadrupole Mass Spectrometers) was applied to investigate the pyrolysis characteristics of cut filler of cigarette at different heating rates(200 K·min~(-1)-800 K·min~(-1)), and a kinetic model for the fast pyrolysis of cut filler at different heating rates was developed. The results showed that: 1) With the increase of heating rates, thermal decomposition overlap region, mass loss rate and devolatilization index of each main component in tobacco were raised. Meanwhile, thermal lags of different extents were also observed. 2) The kinetic model overcame the deviation of kinetic parameters caused by thermal lag via introducing a heating rate correction factor, and predicted the fast pyrolysis behaviors of cut filler at different heating rates more accurately. 3) The release of pyrolysis products, such as acrolein(m/z=56),pyridine(m/z=79), nicotine(m/z=84), phenol(m/z=94) and indole(m/z=117) decreased with the increase of heating rate. The fast pyrolysis characteristics of cut filler are closer to the real state of cigarette combustion and the developed mathematical model for tobacco pyrolysis kinetics is more accurate at high heating rate.福建省中烟工业有限责任公司科技创新项目“卷烟燃烧数学模型的建立及其在卷烟减害中的应用”(FJZYJH2013025

Universities' Science and Technical Achievement Transformation Based on Simulated Annealing Neural Network

通过构建科技成果转化评估指标体系,并借助于bP人工神经网络方法,实现对高校科技成果转化指标体系的综合评价。主要应用主成分分析方法(PCAM)对神经网络的输入层数据进行处理,使用模拟退火算法(SA)与神经网络结合的方法提高评价的精确度,并通过实证分析证明bP神经元网络在高校科技成果评估领域的的适用性。In this paper,we construct an index system of universities' science and technical achievement transformation.Then we accomplish the total evaluation of achievement transformation by using BP neural network method.In order to solve the multi-dimension problem of BP's input layer,this paper embeds the PCA into the model.Then it uses the simulated annealing algorithm to improve the accuracy of evaluation.Empirical research has shown that the model with BP artificial neural network,PCA and simulated annealing algorithm,can preferably evaluate the indexes of universities' science and technical achievement transformation.全国教育科学“十一五”规划课题基金项目(DIA080119);福建省自然科学基金项目(2009J01314