氧弹燃烧法测定固体的分解焓

以碳酸钡分解焓测定为例,探讨了用氧弹热量计测定固体分解焓的方法,建立了固体分解焓氧弹法测定技术。准确称取一定量的测试样品和基准物质,均匀混合后压片,放入氧弹中充入高压纯氧,然后将测试样品在氧弹中完全灰化,并记录燃烧前后时间与量热计温度变化数据,将测试数据用自编的氧弹燃烧法数据处理系统进行分析。结果表明,用氧弹燃烧法测定固体的分解焓是可行和可靠的,对进一步拓展用氧弹法测定煤炭、污泥、饲料、建筑材料等材质的热值具有参考价值。     

低热值工业危废燃烧热值的测定方法

<正>申请公布号:CN107247074A申请公布日:2017.10.13申请人:江苏和顺环保有限公司摘要本发明涉及一种低热值工业危废燃烧热值的测定方法,包括:仪器热容值的标定及样品燃烧热值的测定均在恒温T=18℃的条件下进行,所有样品燃烧热值测定的初始温度T_1和末端温度T_2差值控制在ΔT≈(2±0.5)℃范围内;氧弹热容值的标定:向坩埚中加入约1 g已知热值的苯甲酸热值片对氧弹热量计的热容值进行标定,取多次测量的平均值     

燃烧热测定实验装置中的几点改进

燃烧热测定是一种重要的量热实验,为提高实验质量,我们作了四点改进。 1.改进弹式量热计的放气阀以及充气和漏气的检查为了使试样能完全燃烧,氧弹必需充入氧气,是否已充入,可通过松开放气阀来检查。如氧气减压阀和氧弹充气阀良好,放气嘴松开时     

醇类化合物热值改进剂的定量结构-性质关系研究

醇类化合物燃料作为一种新型的可再生清洁能源,目前是代替燃油及煤的优良环保型燃料.本文计算表征了醇类化合物热值改进剂的4个分子连接性指数和5个量子化学参数,用多元线性回归方法对参数进行了优化筛选,获得了醇类化合物热值改进剂的定量结构与热值性质的关系模型,其相关系数R为0.961.计算结果表明:与醇类化合物热值改进剂的热值显著相关的变量是最低空轨道能量ELUMO、最低空轨道能量与最高占有轨道能量差△E、总能量ET,预测值与相应的实验值较好吻合,所建模型具有良好稳定性和预测能力,与分子连接性指数等的相关程度较好.     

液体火箭发动机燃烧稳定性数值仿真

建立液体火箭发动机燃烧稳定性数值仿真模型, 对液氧/煤油, 煤油/气氧/气氢, 气氢/液氧发动机的两相燃烧稳定性进行了数值仿真. 首次得到的系列自激燃烧振荡的仿真结果与试验规律相符: 氢气有利于烃氧火焰稳定; 提高同轴式喷嘴的气相喷射速度有利于稳定. 对仿真结果的进一步分析表明, 燃烧室头部附近的预混低温区为燃烧振荡提供了能量. 根据仿真结果提出了抑制燃烧不稳定的技术措施: 在推进剂中添加催化剂降低反应活化能, 或者改进喷注器的设计以缩小喷嘴附近的预混低温区.     

卟啉化合物的热化学研究——Ⅳ.精密转动氧弹燃烧热量计的建立与标定

静止弹燃烧热量计对含C、H、O及C、H、O、N的化合物可以给出精度非常高的实验结果,但对于含卤素、硫及金属的有机化合物,由于:(1)不能形成单一氧化态的末态产物;(2)不能形成平衡的气液两相分布;(3)末态产物在弹体与弹壁各部分不能均匀分布;所以在燃烧末态不能获得一个均匀稳定的热力学平衡态,因而得不到精密的实验结果。现在国内外采用的转动弹热量计由于当试样燃烧后可使氧弹同时沿水平轴和垂直轴转动,从而克服了上述困难,得到了稳定的热力学终态。目前转动弹燃烧量热法日益广泛地应用于含硫、     

氧弹量热仪测定生物质原料热值不确定度的评定

生物质原料是重要的环保燃料,具有成本低、来源广、热值高的特点.本文利用标准型氧弹量热仪测定牛粪、猪粪、玉米秸秆和水稻秸秆等生物质原料热值,并对试验结果进行不确定度影响分析,以表征合理地赋予被测量值的分散性,为资源化利用农业废弃物提供依据.本文构建了不确定度评定数学模型,逐层对不确定度来源进行分析和评定,并对各不确定度分...     

煤矸石与半焦富氧混烧特性及污染物排放特性研究

利用热重分析仪和管式炉实验,研究了煤矸石与半焦的富氧混烧特性,考察了半焦混烧比例、O2含量和反应温度对燃烧特性和污染物排放特性的影响.结果表明,混烧半焦和提高O2含量均可显著改善混合燃料的燃烧性能,当半焦混烧比例为75％时,着火和燃尽指数最高.随半焦混烧比例增大,CO和SO2转化率均逐渐降低.提高反应温度,CO转化率降...     

氧弹燃烧-氢化物发生-原子吸收法测定煤中痕量砷

引　　言砷在煤中含量很低 ,属有害元素之一 ,其含量通常采用艾士卡试剂熔样 砷钼兰比色法测定。操作周期长 ,灵敏度低 ,且不适宜少量单个样品的分析。对此 ,作者在有关工作的基础上 ,结合对参考文献的分析 ,进行了氧弹燃烧 氢化物发生 原子吸收法测定煤中砷的研究。实验表明 :样品经氧弹燃烧预处理后 ,不需再经过其它的分离处理 ,方法简便 ,灵敏度及准确度均较好 ,可满足实际样品的测定。2　实验部分2 1　主要仪器与试剂　ＷＦＸ 1Ｄ型原子吸收分光光度计 (北京第二光学仪器厂 ) ;ＧＲ 35 0 0型氧弹式热量计 (长沙仪器厂 ) ;电加热石…     

含碳燃料燃烧热值变化规律

本文利用手册数据 ,通过物理化学计算得出了含碳燃料的燃烧热值变化规律。计算结果的分析表明 :( 1)有机物的燃烧过程是先气化 ,再分解 ,然后氧化。 ( 2 )通过使用催化剂 ,油 (或煤 )与水之间的气化反应可使燃烧完全 ,而气化反应的动力可由混合焓提供 ,因此掺水燃料可以减少污染 ,提高能量利用率。 ( 3)由此增加的能量受相关过程的限制 ,不会超乎寻常地增大。     

Magnesium boride sintered as high-energy fuel

Boron was chosen as fuel owing to its excellent thermodynamic values for combustion. The difficulty of the boron in combustion is the formation of a surface oxide layer, which postpones the combustion process, reducing the performance of the rocket engine. In this paper, magnesium boride was sintered as high-energy fuel as a substitute for boron. The combustion heat and efficiency of magnesium boride and boron were determined using oxygen bomb calorimeter. The combustion characteristics of magnesium boride were investigated by thermal analysis, chemical analysis, XRD, and EDS. Results show that the combustion performance of magnesium boride are better than that of amorphous boron in oxygenated environments. The evaporation of magnesium in magnesium boride combustion process prevent the formation of a closed oxide layer, leading to higher combustion efficiency.     

Rocket Engine with Continuous Detonation Combustion of the Natural Gas–Oxygen Propellant System

In a demonstrator of a detonation rocket engine (DRE) using the natural gas–oxygen propellant system, a high (270 s) specific impulse at sea level at a low (32 atm) mean combustor pressure was experimentally obtained for the first time. Comparison of these characteristics with the respective ones (263 s and 61 atm) of the well-known Russian RD 170-A liquid-propellant rocket engine using deflagration combustion of the kerosene–oxygen propellant system showed that the specific impulse at sea level in the DRE is close to that in the deflagration-combustion engine but is produced at half as high a mean combustor pressure. This indicates that the energy efficiency of detonation combustion exceeds that of deflagration combustion, and that there is room to improve the weight–size characteristics of the turbopump unit in the DRE.     

Borides and vitreous compounds sintered as high-energy fuels

Boron was chosen as fuel in view of its excellent thermodynamic values for combustion, as compared to traditional fuels. The problem of the boron in combustion is the formation of a surface layer of oxide, which delays the ignition process, reducing the performance of the rocket engine. This paper presents a high-energy fuel for rocket engines. It is composed of sintered boron (borides and carbides and vitreous compounds) with a reducing chemical agent. Borides and boron carbide were prepared since the combustion heat of the latter is similar to that of the amorphous boron (in: K.K. Kuo (Ed.), Boron-Based Solid Propellant and Solid Fuel, Vol. 427, CRC Press, Boca Raton, FL, 1993). Several chemical reducing elements were used, such as aluminum, magnesium, and coke. As the raw material for boron, different compounds were used: amorphous boron, boric acid and boron oxide.     

2-氯丁烷、1,2=二氯丁烷气态生成焓的测量

用转动氧弹燃烧热量计测量了298.15K时2-氯丁烷和1,2-二氯丁烷的标准液态燃烧反应内能变化值,得到了它们的标准所态生成焓值,并进一步考查了二氯取代地氯代烷烃气态生成焓值的影响量.     

卟啉化合物的热化学研究Ⅰ. 精密燃烧量热装置及标定

本文报道了一套用热敏电阻作测温元件的精密静弹燃烧量热装置。数据处理用电子计算机按自编程序完成。用中国计量科学院提供的量热基准苯甲酸标定了量热计的能当量, 其精密度(2s.d.m计)为0.01％。利用此仪器测得三羟甲基氨基甲烷的燃烧能为△_cu°(298.15 K)=-20030.3±6.0 Jg~(-1), 与文献值吻合, 证实了本装置的可靠性。     

Modernization and validation of an isoperibol rotating bomb calorimeter for the measurement of energies of combustion of sulphur compounds

A rotating bomb calorimeter belonging to the Laboratory of Chemistry and Process Engineering (UCP) at ENSTA ParisTech since the 1960s was modernized and re-set in order of service for the measurement of heats of combustion of sulphur-containing compounds. The parts of the calorimeter that were replaced concerned essentially the thermal regulation, firing system and data acquisition, while most of the mechanical organs were found to work perfectly. The apparatus was tested extensively and calibrated using standard benzoic acid. The standard energy of combustion of thianthrene was measured to validate the operating protocol for sulphur compounds.     

Synergistic effect of carbon nanotubes and decabromodiphenyl oxide/Sb2O3 in improving the flame retardancy of polystyrene

Brominated flame retardant polystyrene composites were prepared by melt blending polystyrene, decabromodiphenyl oxide, antimony oxide, multi-wall carbon nanotubes and montmorillonite clay. Synergy between carbon nanotubes and clay and the brominated fire retardant was studied by thermogravimetric analysis, microscale combustion calorimetry and cone calorimetry. Nanotubes are more efficient than clay in improving the flame retardancy of the materials and promoting carbonization in the polystyrene matrix. Comparison of the results from the microscale combustion calorimeter and the cone calorimeter indicate that the rate of change of the peak heat release rate reduction in the microscale combustion calorimeter was slower than that in the cone. Both heat release capacity and reduction in the peak heat release rate in the microscale combustion calorimeter are important for screening the flame retardant materials; they show good correlations with the cone parameters, peak heat release rate and total heat released.     

有机物燃烧热测定方法的改进

对有机物燃烧热的测定方法进行了改进。改变点火丝的安装方法,采用高性能量热计,改变氧弹内氧气的压力及燃烧样品的用量,确定了新的测定方法。采用新的测定方法测定萘的燃烧热,测定结果的相对误差为0．05％,相对标准偏差为0．077％。     

Improving the completeness of combustion of boron particles in a solid-fuel ducted rocket owing to distributed air supply to the secondary combustor

A model of combustion of boron particles in ducted rocket using distributed air supply to the secondary combustor was developed for the first time. The completeness of boron combustion in ducted rocket using air supply to the secondary combustor through one outlet or two outlets (distributed air supply) was calculated. It was shown that, in some cases, distributed air supply significantly (by a factor of 1.5–3) decreases the time of complete combustion of boron particles and thereby increases the completeness of fuel combustion in ducted rocket. The modeling results agree with the known experimental data.