锅炉传热介质标准体系研究

结合我国对现代环境、安全等各方面的要求,在对我国锅炉传热介质标准的现状及其存在问题进行分析的基础上,提出了建设标准体系的目的、原则及其基本构成等。建立相应的标准体系对促进我国锅炉传热介质安全、经济、节能、环保运行,推动其产业发展,具有重要的现实意义和长远的战略意义。     

新型转化气废热锅炉的开发应用

针对原厚管板废热锅炉难以适应合成氨生产中高温高压的工况条件 ,开发设计了无管板集箱和挠性薄板废热锅炉 ,就其结构、应用情况及性能特点做了介绍     

气相温度脉动对碳黑生成反应的影响(英文)

The effects of gas temperature fluctuations on soot formation and oxidation reactions are investigated numerically in a reacting flow. The instantaneous variations of soot mass fraction with time are obtained under the time-averaged gas temperature of 1500-1700 K. The simulation results show that the gas temperature fluctuation has obvious influence on the instantaneous processes of soot formation and oxidation. Within the present range of gas temperature, the gas temperature fluctuation results in generally lower soot mass fraction comparing to that without gas temperature fluctuation. The increase in the fluctuation amplitude of gas temperature leads to decrease in time-averaged soot mass fraction and increase in time-averaged soot particle number density.     

煤气化-无烟燃烧立式锅炉内空气动力场的数值模拟研究

采用RNGk ε湍流模型、其动量方程利用具有三阶精度的QUICK格式离散的方法 ,对一台采用了无烟燃烧技术的锅炉炉内冷态流场进行了数值模拟 ,并根据模拟结果对这一新技术进行了理论上的探讨     

以氢气作燃料的四氟乙烯装置蒸汽过热炉的设计

介绍了用氢气作为燃料的四氟乙烯装置蒸汽过热炉的设计特点,探讨了设计中如何保证氢气燃烧系统的安全运行以及提高蒸汽过程炉热效率的措施。     

环境因素对发射药升温速率及安全性的影响分析

对环境因素或边界条件对发射药热自然现象的影响规律进行了数值模拟研究。结果发现：环境的温度以及装有发射药的容器与周围环境间的换热条件,对发射药的升温速率及其安全性有非常大的影响。研究结果表明,为了提高发射药储存时的安全性,必须保持良好的通风换热条件     

保温层对废热锅炉温度及温差应力影响的有限元分析

对壳体外部设有保温层及未设保温层的两台废热锅炉用ANSYS进行了数值模拟,分析了该废热锅炉的温度场分布情况,计算出由温度梯度产生的温差热应力。并将两台废热锅炉的温度和温差热应力情况进行对比,得出保温层可以降低外壁面温度和温差热应力的结论。     

Influence of Operating Conditions on the Freeze-Drying of Frozen Particles in a Fixed Bed and Modeling Data

Experimental runs have been carried out to investigate the influence of shelf temperature and total gas pressure in the chamber on the primary drying sublimation kinetics of a packed bed of frozen spherical particles of a model 16.6% (w/w) sucrose solution. Sublimation kinetics determined, in situ and on line, by weighing continuously the freeze-dried sample, were observed to increase with the total gas pressures and with the shelf temperatures. A physical model, based on the hypothesis that two “sublimation fronts” advancing at the same time from the bottom of the bed, due to the contact heat flux, and from the top of the bed, due to radiation heat flux, was proposed. Fair agreement was found between simulated and experimental data.     

固定床煤气炉操作条件的优化

简要介绍了固定床煤气发生炉生产中的要点,认为在生产中需要提高原料利用率,加快技术改造,合理优化工艺指标,精心平稳操作,才能达到经济运行、降低成本的目的.     

利用SPS软件分析输气管道的瞬态工况

准确了解天然气管道的瞬时工况变化情况,对于管道运营管理部门来说,有助于其调度管理和制定管网系统的运行方案,并提前制定相应的应急措施,以此保障天然气管道系统的安全平稳运行。为此,收集了某天然气管道的相关基础资料,利用SPS仿真模拟软件建立某管道的水动力仿真模型,进行相关分析,并得到以下相关结论:当压缩机站内的压缩机组事故停机时,通过该站的瞬时流量变为零,进站压力上升,出站压力下降;天然气管道发生泄漏时,泄漏点处的上游流量瞬间上升,下游流量瞬间下降;天然气管道发生截断阀紧急关断时,通过前后阀门的流量变为零,通过此管段的流量也变为零,同时上游管段流量下降,处于不断储气的状态,压力不断增大。该分析结果对天然气管道的输送安全起到指导作用。     

长输天然气管道放空火炬热辐射距离计算方法探讨

介绍了在考虑允许辐射强度和风速的影响因素下,长输天然气管道放空火炬热辐射距离的一般计算方法和Brzustowski-Sommer计算方法,并将计算结果与挪威船级社PHAST软件的计算结果进行分析比较,得出放空火炬热辐射距离一般计算方法的计算结果偏于保守,从而确定了长输管道放空火炬热辐射距离的计算,应以其一般计算方法为准。     

Process simulation of natural gas steam reforming: Fuel distribution optimisation in the furnace

This paper describes a two-step method to simulate the natural gas steam reforming for hydrogen production. The first step is to calculate reforming tube length and fuel distribution with equilibrium approach associated with heat transfer. The second step is to calculate and validate reforming performance with kinetic model. A short-cut simulation of hydrogen plant has also been performed to calculate inputs for the reformer model, such as total flow rate and composition of mixed fuel burning in the furnace chamber. Heat transfer, especially radiative heat transfer, is the key role in the steam reforming technology, due to the high heat fluxes involved. For this reason, energy modelling of the furnace chamber has been performed. The simulation evaluates the most important design variables, as tubes height, maximum tube-wall temperature, and tube pressure drop. The heat flux profile can be selected to have suitable metal temperatures to lengthen the reformer tube life. The model calculates the design parameters for reforming tube and fuel distribution among burners.     

油气集输过程中低温余热利用热泵技术的概述

当前在油气集输系统中,低温(40~50℃)余热资源非常的丰富,造成了很大能源浪费和热"污染"。改善能源的利用效率,对于解决能源危机非常的关键。热泵是油气集输系统中低温余热进行回收的核心装置,其不仅能够提高能源品味,还具有操作简单,技术较成熟的特点。分析了油气集输系统的用能状况和能源消耗的原因,还论述了低温余热回收热泵技术和对热泵市场进行介绍。     

高温及升温速率对砂浆气体渗透性与孔隙率的影响

高温不仅降低砂浆的力学性能,还会对其耐久性产生重大的影响。通过高温马弗炉以3种不同升温速率(即5 ℃/min、10 ℃/min、15 ℃/min)加热砂浆至400 ℃、500 ℃、600 ℃来模拟火灾试验。通过新的试验技术(允许在围压下同时测量气体渗透性和孔隙率)研究了不同温度损伤后砂浆的气体渗透性和孔隙率以及力学性能的变化。结果表明,随着升温速率的加快以及温度的升高,砂浆气体渗透率与孔隙率逐渐增大。与未升温相比,当以15 ℃/min加热至600 ℃时,砂浆气体渗透率增加了2个数量级,孔隙率增大了1.77倍;在加卸载围压过程中,砂浆气体渗透率与孔隙率均不可逆地降低;升温速率越大,加热温度越高,砂浆气体渗透率与孔隙率对围压就越敏感。孔隙率对围压的敏感性与气体渗透率相比较小,但孔隙率对围压的敏感性证实了加卸载围压过程中裂纹不可逆闭合与孔隙不可逆破碎;当以3种升温速率加热砂浆至400 ℃、500 ℃和600 ℃时,随着升温速率的加快以及温度的升高,砂浆的抗压强度逐渐降低。     

Retrofitting of the Heat Exchanger Network with Steam Generation in a Crude Oil Distillation Unit

Steam generation through hot streams has an important impact on the utility consumption of a crude oil distillation unit. Retrofitting of the heat exchanger network with steam generation in a crude oil distillation unit is studied with regard to efficient energy usage. The grand composite curve is employed to provide insights into the steam generation problem, and a mixed‐integer linear programming model, presented previously for heat integration through hot discharges/feeds and steam generation, is used to obtain the optimal parameters for steam generation. Three heuristic rules are then proposed to determine suitable hot streams for steam generation. Finally, the heat exchanger network is modified based on pinch technology. After the retrofit, the hot and cold utility decrease.     

25000m~3低温液化气储罐保冷及防腐

介绍了大型进口低温液化气储罐保冷参数、保冷结构、主要保冷材料、施工方法和质量控制关键及储罐防腐工艺     

温度对PE燃气管热熔焊接接头性能的影响

主要研究了聚乙烯(PE)燃气管热熔焊接接头在不同温度下的力学性能,通过不同温度下PE材料的拉伸破坏实验,根据不同温度下PE燃气管道焊接接头拉伸应力及拉伸应变,利用数值拟合的方法建立了PE材料接头的最大应力和断裂伸长率与温度的函数关系。其中卷边的存在容易产生应力集中使管道断裂,无卷边试样断裂伸长率总体高于有卷边试样且温度越高越明显,去除卷边对拉伸强度影响较小,可提高试样的断裂伸长率。温度对PE材料的拉伸强度、断裂伸长率影响较大,温度升高,PE材料的拉伸强度降低,断裂伸长率增加。     

Effects of Viscous Dissipation and Rarefaction on Parallel Plates with Constant Heat Flux Boundary Conditions

The effect of viscous dissipation and rarefaction on heat transfer characteristics of hydrodynamically and thermally fully developed flow between parallel plates with constant heat flux conditions is analyzed. Three different types of heat flux boundary conditions, i.e., both plates kept at different constant heat fluxes, both plates kept at equal constant heat fluxes, and one plate insulated, are applied. In all cases, closed form expressions are obtained for the temperature distribution and Nusselt number. Viscous dissipation, rarefaction, and heat flux ratio are found to influence the heat transfer substantially. The present predictions are verified for the cases which neglect the microscale and viscous heating effect. The obtained results are in good agreement with other analytical results.     

质子交换膜燃料电池电堆的动态热模型及其温度控制

A dynamic thermal transfer model of a proton exchange membrane fuel cell (PEMFC) stack is developed based on energy conservation in order to reach better temperature control of PEMFC stack. Considering its uncertain parameters and disturbance, we propose a robust adaptive controller based on backstepping algorithm of Lyaponov function. Numerical simulations indicate the validity of the proposed controller.