气化炉激冷室工作过程数学模拟

针对水煤浆气化炉激冷室的工作特点,建立了激冷室下降管的传热传质数学模型,并进行了数值计算,据此分析了下降管内合成气的温度分布与进口流速等参数的关系,为进一步探讨激冷室的工作过程,改进气化炉激冷室设计提供了一定的理论依据.     

虹吸液位控制法在四喷嘴气化炉烘炉中的应用

重点分析四喷嘴对置式水煤浆加压气化炉在烘炉过程中的控制要点,阐述了气化炉烘炉时气化炉激冷室液位的控制方法及注意事项。介绍了气化炉激冷室液位快速调节的设计思路,利用虹吸现象对液位进行有效控制,避免出现气化炉激冷室液位快速上涨,液位漫过下降管导致气化炉负压波动,造成事故的发生。实践表明:虹吸液位控制法解决了因气化炉液位上涨过快或液位调节不当造成气化炉内负压波动引起的烘炉事故,对烘炉具有极高的控制效果且操作便捷。     

多元料浆气化炉激冷室液位指标的讨论

多元料浆气化炉激冷室液位是其在正常运行过程中需要重点监控的工艺指标。根据对气化炉激冷室带水原因分析与讨论所得出的结论以及气化炉激冷室内件的布局,得出合理的多元料浆气化炉激冷室液位控制指标,以达到消除气化炉激冷室带水现象的目的。经计算得出:气化炉正常生产时,激冷室高液位为5.2 m,正常液位为4.5 m,低液位为3.8 m,停车液位为3.1 m。     

带中间激冷器的气化炉激冷室下降管数值研究

为了改善激冷室的降温效果，文中提出了一种改进结构——在激冷室的中心部位增加中间激冷器，并且对该方案进行数学模拟，计算采用K-ε湍流模型和四通量辐射模型，并把有中间激冷器的气化炉激冷室下降管的计算结果与在役结构激冷管的计算结果进行比较来考查新方案的效果。计算表明带有中间激冷器的气化炉激冷室下降管的传热降温效果和流场特性优于在役结构激冷室下降管。     

气化炉激冷室液位的测量与控制

气化炉激冷室液位的测量与控制关系到气化炉及气化装置的安全,对于稳定料浆气化过程,延长气化炉的使用寿命具有重要的意义。本文介绍了气化炉激冷室液位的测量与控制方法,论述了用双法兰差压变送器测量气化炉激冷室液位时,变送器的量程和迁移量的计算方法以及保护双法兰差压变送器所采取的措施。     

水煤浆气化炉合成气带水问题分析及应对措施

介绍了水煤浆气化炉激冷室的内部结构和工艺过程;分析了气化炉合成气带水的原因及其对装置运行的危害;采取了调节氧煤比、优化激冷室结构和激冷环结构以及在气化炉合成气出口管道增设气液分离器等技改措施,有效避免了合成气带水。     

大型渣油气化炉激冷室热质传递过程模拟

对现行８．５３ＭＰａ德士古渣油气化炉激冷室中热质传递过程进行了分析、研究，从数学模型着手，进行模拟计算，模拟结果与工业数据吻合良好。通过模拟揭示了激冷过程本质特征，探讨了现行激冷环损坏的主要原因。     

航天炉上升管和下降管堵塞原因分析及预防措施

针对航天气化炉上升管与下降管间环隙堵塞的实际问题,分析了堵塞的宏观检修图,探讨激冷室液位、原料煤、煤线流量对其造成的影响。结果显示,气化炉长时间高负荷运行及激冷室液位偏低是环隙堵塞的主要原因,最后从原料煤供应来源、气化炉负荷调整速度、水质及专业操作等角度给出预防措施,有益于气化炉长周期运行。     

德士古气化炉下降管的损坏原因及预防

分析德士古气化炉中的激冷室的工艺状况,再结合某厂德士古气化炉的实际生产情况分析下降管的损坏原因及其避免手段。     

新型多喷嘴对置式气化炉激冷室的改造

介绍了新型多喷嘴对置式气化炉激冷室工艺流程以及在工艺、设备内部结构上的优点,同时结合国泰公司四喷嘴气化炉激冷室运行情况,总结了静态破渣器、鼓泡床、托砖盘法兰及冲洗水、合成气出口挡板等内部件改造及应用情况,经过改造后,提高了气化炉激冷室运行周期,达到了集渣畅通、破泡条运行周期长、锅底温度可控等良好效果。     

微量有机化合物催化燃烧反应器数学模拟

建立了甲苯、二甲苯、环己烷催化燃烧反应器的一维拟均相数学模型 ,在MnCuOx/Al2 O3 催化剂上催化燃烧反应动力学采用Langmuir双曲型动力学方程。模拟计算了废气处理量、废气中有机化合物的浓度、床层入口温度对净化率的影响     

Experimental study of traveling waves in nonadiabatic fixed bed reactors for the oxidation of carbon monoxide

An experimental study of axial temperature profiles in a nonadiabatic tubular fixed bed reactor has been made under the transient operation. The catalytic carbon monoxide oxidation occuring on a Pt/alumina catalyst has been used. Unlike the adiabatic conditions the velocity of a traveling temperature wave in a nonadiabatical arrangement depends on its axial position. In certain regions of inlet concentration multiple temperature fronts have been observed. For low inlet CO concentration a downstream temperature wave results and the lower (kinetic) steady state is dominant. For high inlet CO concentration an upstream propagating front results and the upper steady state is dominant. For a downstream moving wave oscillations of wave velocity, hot spot temperature and exit conversion have been measured. For certain operating conditions periodic behavior of temperature profiles in the reactor has been observed.     

管式反应器中苯乙烯连续本体热聚合过程模型化和数值模拟

建立了管式层流反应器中苯乙烯本体热聚合过程的模型。数值模拟了反应介质流速和温度沿反应器的轴向和径向的分布,考察了反应器的几何尺寸、壁温、反应介质入口温度和流量对反应器出口转化率和产物相对分子质量的影响。结果表明,反应器的几何尺寸和反应器壁温及进料质量流量对单体转化率影响较大,而入口温度影响不大。     

Polarization characteristics and fuel utilization in anode-supported solid oxide fuel cell using three-dimensional simulation

A three-dimensional numerical simulation for anode-supported tubular solid oxide fuel cell (SOFC), which is characterized by good electrical conductivity, has been carried out. Performance results by simulation are in good agreement with those by experiments, reported in [7]. Effect of various process conditions such as operating temperature, inlet velocity of fuel, and flow direction of inlet gases on the cell performance and fuel utilization has been further scrutinized. Polarization curve rises with increasing temperature of preheated gases and chamber, resulting from the incremented activity of catalysts within electrode. An effective way to reduce the temperature variation in the single cell with increasing current density has been sought, considering the temperature-dependent thermal expansion of materials. It has also been found that the fuel utilization is enhanced by increasing the cell length and operating temperature and lowering the inlet velocity of fuel.     

Theoretical and experimental investigation of humidification-dehumidification desalination unit

A theoretical and experimental investigation of humidification-dehumidification desalination system is presented. The system is based on an open cycle for water and a closed cycle for the air stream. The air is circulated either by natural or forced circulation. The system modeling is based on various heat and mass balance equations and their numerical solution. The effect of operating parameters on the system characteristics has been investigated. An experimental test set-up has been fabricated and assembled. The set-up has been equipped with appropriate measuring and controlling devices. Detailed experiments have been carried out at various operating conditions and using several packing materials. The heat and mass transfer coefficients have been obtained experimentally and fitted in forms of empirical correlations.The results of the investigation have shown that the system productivity increases with the increase in the mass flow rate of water through the unit. Water temperature at condenser exit increases linearly with water temperature at humidifier inlet and it decreases as water flow rate increases. The higher water temperature at humidifier inlet or water flow rate, the higher is the air temperature and humidity ratio at condenser inlet and exit. A maximum productivity of 5.8 liter/h has been obtained using wooden slates packing and with forced air circulation. No significant improvement in the performance of the desalination unit has been achieved by forced circulation of air at high water temperatures. The average relative deviation of theoretical predictions from measurements is (− 0.9%) in the air temperature at condenser inlet, (3.8%) in the humidity ratio at condenser exit and (− 1%) in the water temperature at condenser exit.     

操作参数对双蒸发压缩/喷射制冷系统性能的影响

实验研究了操作参数（冷凝器进水温度、高温蒸发器进水温度和低温蒸发器进水温度）对双蒸发压缩/喷射制冷系统及两相喷射器性能的影响。结果显示,喷射器引射系数随冷凝器进水温度和高温蒸发器进水温度的升高而减小,随低温蒸发器进水温度的升高而增大;喷射器压升比随冷凝器进水温度和高温蒸发器进水温度的升高而增大,随低温蒸发器进水温度的升高而减小。冷凝器进水温度和高温蒸发器进水温度对制冷系统性能的影响较大,而低温蒸发器进水温度对制冷系统性能的影响较小。其中,冷凝器进水温度每降低5℃,制冷系统COP增加0.44;高温蒸发器进水温度每升高2℃,制冷系统COP增加0.16。结果可供双蒸发压缩/喷射制冷系统的设计和运行参考。     

复杂冷却循环水系统的建模与优化

建立了新的复杂冷却循环水系统的费用模型。利用优化软件GAMS求解了各冷却塔的最佳进出塔水温、用户进出水温、分配系数、循环水量、风量和循环水泵及风机功率等参数。通过工程实例验证了其可行性,并将其与原模型相比较。结果表明,新模型的操作费用减少了13%左右。因此,当处理复杂循环水系统时,应选取新模型。     

鲁奇甲醇生产装置数学模拟和工况分析——(Ⅰ)鲁奇副产蒸汽管壳型甲醇合成塔

以一氧化碳加氢和二氧化碳加氢为独立反应、甲醇和二氧化碳为关键组分,建立了鲁奇副产蒸汽管壳型甲醇合成塔催化床的一维拟均相数学模型,并求得管内各组分气体浓度和温度分布。讨论了不同操作条件对出口甲醇浓度和产量的影响。由于管外副产4.0MPa 的蒸汽,床层温度平稳。     

Effect of fluctuations in polymer melt temperature of linear density of yarn

Conclusions The effect of polymer melt temperature fluctuation at the inlet to the metering pump on nonuniformity in yarn linear density has been studied.It has been shown that considerable fluctuation in yarn linear density, caused by change in melt temperature, takes place also in individual working sites.A considerable difference in the temperature of the melt going to individual working sites of machines for spinning technical yarns has been discovered.Fluctuation in the linear density of yarn caused by variation in melt temperature at the inlet to the metering pump may reach 0.3–0.8% in spinning technical yarns, depending on the construction (group or individual) of the spinning machine melting devices.Translated from Khimicheskie Volokna, No. 5, pp. 45–47, September–October, 1984.     

Methanol synthesis in a forced unsteady-state reactor network

The feasibility of carrying out the low-pressure methanol-synthesis process in forced unsteady-state conditions, using a network of three catalytic fixed bed reactors with periodical change of the inlet position, has been investigated; advantages and limitations in comparison with the previously proposed reverse-flow reactor have been highlighted. The effect of the main operating parameters—inlet temperature, switching time, inlet flow rate—has been studied. A cyclic-steady-state condition and auto-thermal behaviour are possible; nevertheless, they are attainable only for switching times varying in two narrow ranges. Out of these regions, complex steady-states of high periodicity, where conversion is low, or extinction of the reactors occur. For low values of the switching time, the establishing of optimal temperature profiles along the network allows higher conversions than in the reverse flow reactor. Furthermore, the performances of the network are weakly affected by wash-out, the removal of unconverted gas in correspondence of switching, which is in intrinsic disadvantage of reverse flow operation.