TH—38水稳剂及其在柴油机发电机组上的应用

使用ASTM-D1384-87标准和极化曲线法对TH-38水稳剂的缓蚀性能进行研究,并与进口同类药剂Nalco-2000、Qc-2 进行比较,结果表明:TH-38的缓蚀、分散性能达到进口药剂Nalco-2000、Qc-2的水平,可以替代进口药剂在柴油机发电机组上的密闭高温循环水系统使用。     

二级通信网络路灯智能控制系统设计

提出了基于GTM900C和SI4421构建的二级通信网络路灯控制系统设计方法,通过设计出合理的通信协议,实现路灯照明的智能控制。详细介绍了二级通信网络路灯智能控制系统的总体设计,网关及路灯控制节点的硬件设计及整个通信系统间的通信协议的设计。通过GPRS网络及自组建的局域网络,该系统可靠地实现了路灯的智能控制,定时开关,状态获取,以及路灯控制节点的故障自报警等功能。     

基于增强型游标效应的光纤温度传感器

提出了一种基于增强型游标效应增敏的高灵敏度光纤温度传感器,该传感器由对温度均敏感的法布里-珀罗干涉计（Fabry-Perot Interferometer,FPI）与萨格奈克干涉计（Sagnac Interferometer,SI）级联构成。FPI为聚二甲基硅氧烷（PDMS）填充空芯光纤（HCF）形成的PDMS腔,SI由单模光纤环内熔接一段熊猫光纤而成。FPI和SI具有相反的温度响应,随温度的升高,FPI的干涉谱逐渐红移,而SI的干涉谱逐渐蓝移,从而产生增强型游标效应,其温度灵敏度远大于单个FPI或单个SI,且放大倍率明显高于普通游标效应。实验结果表明：36～39℃温度范围内,该传感器温度灵敏度达到了-57.85 nm/℃,分别为单个FPI和SI灵敏度的44.8倍和30.8倍,分别为普通游标效应放大倍率的2.56倍和1.66倍。该传感器具有灵敏度高、稳定性能好、制备成本低等优点,具有非常好的应用前景。     

A point model for the design of a sulfur trioxide decomposer for the SI cycle and comparison with a CFD model

Operating under the harsh environment with the significant energy consumption, the sulfur trioxide decomposer is one of the most important components, yet challenging tasks for the designers of an efficient SI cycle. We developed a point model to provide important guidelines for designers of a sulfur trioxide decomposer through estimating outlet physical quantities, such as outlet decomposition ratio, outlet temperature, and pressure drop of a sulfur trioxide decomposer. Then, results of the point model were compared to independent predictions obtained using a CFD model over a wide range of conditions with good agreement. The model indicates that decomposition ratio is a function of the representative non-dimensional design parameter and inlet flow composition. As inlet flow composition rarely affects outlet decomposition ratio, we found out that outlet decomposition ratio can be approximated solely as a function of the non-dimensional design parameter. We demonstrated that the model can provide general guidelines for designers of a sulfur trioxide decomposer to achieve a target decomposition ratio with an economical design. It turns out that an increase in operating pressure and catalyst surface area leads to an increase in outlet decomposition ratio while the reverse is true for an increase in mass flow rate.     

Effects of hydrogen addition and cylinder cutoff on combustion and emissions performance of a spark-ignited gasoline engine under a low operating condition

Because of the low combustion temperature and high throttling loss, SI (spark-ignited) engines always encounter dropped performance at low load conditions. This paper experimentally investigated the co-effect of cylinder cutoff and hydrogen addition on improving the performance of a gasoline-fueled SI engine. The experiment was conducted on a modified four-cylinder SI engine equipped with an electronically controlled hydrogen injection system and a hybrid electronic control unit. The engine was run at 1400 rpm, 34.5 Nm and two cylinder cutoff modes in which one cylinder and two cylinders were closed, respectively. For each cylinder closing strategy, the hydrogen energy fraction in the total fuel (βH₂)$\left({\beta }_{{\text{H}}_2}\right)$ was increased from 0% to approximately 20%. The test results demonstrated that engine indicated thermal efficiency was effectively improved after cylinder cutoff and hydrogen addition, which rose from 34.6% of the original engine to 40.34% of the engine operating at two-cylinder cutoff mode and βH₂=20.41%${\beta }_{{\text{H}}_2}=20.41\%$. Flame development and propagation periods were shortened with the increase of the number of closed cylinders and hydrogen blending ratio. The total cooling loss for all working cylinders, and tailpipe HC (hydrocarbons), CO (carbon monoxide) and CO₂ (carbon dioxide) emissions were reduced whereas tailpipe NO_x (nitrogen oxide) emissions were increased after hydrogen addition and cylinder closing.     

Exergy analysis of a simulation of the sulfuric acid decomposition process of the SI cycle for nuclear hydrogen production

This article details comprehensive energy and exergy analyses of the sulfuric acid decomposition process of the sulfur–iodine (SI) thermochemical cycle for hydrogen production. Energy and exergy efficiencies of the proposed process were evaluated over a variety of reaction temperatures and pressures. At an atmospheric temperature of 25 °C, the calculated values of exergy destruction of the H₂SO₄ decomposer ranged between 157 kJ/mol and 360 kJ/mol over reaction temperatures of 800–1000 °C and pressures between 1 and 50 atm. It was shown that the exergy efficiency of the H₂SO₄ decomposer improved with an increase in reaction temperature, while reaction pressure had a negative effect on exergy efficiency.     

发动机非常规排放物甲醛的检测与分析

以Flyer M-TCE汽油发动机为对象,以环境空气中甲醛测定方法为基础,采用便携式现场甲醛测定仪,分别进行了93号汽油、甲醇汽油（M15、M25、M85）、乙醇汽油（E10、E25）在一定工况下的非常规排放物———甲醛的检测。结果表明,发动机燃用汽油和醇燃料时,排气中都会产生醛类排放物,且随着混合燃料中的醇含量增加,排气中醛类排放物也相应增加;同一种燃料进行测试时,甲醛排放随着功率的增加呈先增大后减小的趋势;双三元催化器对甲醛有一定的催化作用。通过台架实验得到大量醇类燃料发动机甲醛排放数据,为今后开发醇类燃料汽车燃烧系统及制订排放标准提供依据。     

Ceria as a catalyst for hydrogen iodide decomposition in sulfur–iodine cycle for hydrogen production

In this work, ceria (CeO₂) prepared with different methods and at various calcination temperatures have been tested to evaluate their effect on hydrogen iodide (HI) decomposition in sulfur–iodine (SI) cycle at various temperatures. The CeO₂ catalysts' strongly enhance the HI decomposition by comparison with blank test, especially gel CeO₂ 300. TG–FTIR, BET, XRD, TEM and TPR were performed for catalysts' characterization. The results show that the CeO₂ catalyst synthesized by citric-aided sol–gel method and calcined at low temperature (<500 °C) shows more lattice defects, smaller crystallites, larger surface area and better reducibility. Oxygen can promote the significantly rapid surface reaction, but simultaneously consume hydrogen species (H) contained in HI. Lattice defects, especially the reduced surface sites, i.e., Ce³⁺ and oxygen vacancy, play the dominant role in surface reactions of HI decomposition. A new reaction mechanism for HI catalytic decomposition over CeO₂ catalyst is proposed.