深度调峰背景下,对火电机组的灵活性要求越来越高。锅炉低负荷运行下存在燃烧火焰偏斜、管内工质分配不均以及受热面超温爆管等问题。为保证火电机组安全、稳定、灵活的运行,有必要对锅炉水冷壁参数分布进行详细研究。该文建立锅炉耦合...深度调峰背景下,对火电机组的灵活性要求越来越高。锅炉低负荷运行下存在燃烧火焰偏斜、管内工质分配不均以及受热面超温爆管等问题。为保证火电机组安全、稳定、灵活的运行,有必要对锅炉水冷壁参数分布进行详细研究。该文建立锅炉耦合模型,包括燃烧侧模型、工质侧模型和受热面壁温计算模型,可实现锅炉燃烧侧和工质侧以及受热面壁温的耦合计算。基于Fluent平台开展锅炉燃烧侧流动、燃烧和传热等过程以及受热面壁面温度的计算,采用用户自定义函数(user defined function,UDF)开展工质侧流动和传热过程计算,两者以受热面为边界进行数据交互与更新迭代。基于该模型对某1000 MW双切圆锅炉进行研究,结果表明:1)炉膛出口氧量和飞灰含碳量模拟值分别为2.53%和2.61%,水冷壁出口工质温度为744.59 K,模拟结果与现场实际测量值一致性较好;2)采用耦合模型探究水冷壁的热流密度、工质温度、传热系数以及管壁温度详细分布。研究结果有利于为锅炉故障诊断和运行优化提供更加准确的参考信息。展开更多
The pressure solution model of granular aggregates was introduced into a FEM code which was developed for the analysis of thermo-hydro-mechanical(T-H-M) coupling in porous medium. Aimed at creating a hypothetical mode...The pressure solution model of granular aggregates was introduced into a FEM code which was developed for the analysis of thermo-hydro-mechanical(T-H-M) coupling in porous medium. Aimed at creating a hypothetical model of nuclear waste disposal in unsaturated quartz aggregate rock mass with laboratory scale, two 4-year computation cases were designed: 1) The porosity and permeability of rock mass are functions of the pressure solution; 2) The porosity and the permeability are constants. Calculation results show that the magnitude and distribution of stresses in the rock mass of these two calculation cases are roughly the same. And, the porosity and the permeability decrease to 43%-54% and 4.4%-9.1% of their original values after case 1 being accomplished; but the negative pore water pressures in cases 1 and 2 are respectively 1.0-1.25 and 1.0-1.1 times of their initial values under the action of nuclear waste. Case 1 exhibits the obvious effect of pressure solution.展开更多
文摘深度调峰背景下,对火电机组的灵活性要求越来越高。锅炉低负荷运行下存在燃烧火焰偏斜、管内工质分配不均以及受热面超温爆管等问题。为保证火电机组安全、稳定、灵活的运行,有必要对锅炉水冷壁参数分布进行详细研究。该文建立锅炉耦合模型,包括燃烧侧模型、工质侧模型和受热面壁温计算模型,可实现锅炉燃烧侧和工质侧以及受热面壁温的耦合计算。基于Fluent平台开展锅炉燃烧侧流动、燃烧和传热等过程以及受热面壁面温度的计算,采用用户自定义函数(user defined function,UDF)开展工质侧流动和传热过程计算,两者以受热面为边界进行数据交互与更新迭代。基于该模型对某1000 MW双切圆锅炉进行研究,结果表明:1)炉膛出口氧量和飞灰含碳量模拟值分别为2.53%和2.61%,水冷壁出口工质温度为744.59 K,模拟结果与现场实际测量值一致性较好;2)采用耦合模型探究水冷壁的热流密度、工质温度、传热系数以及管壁温度详细分布。研究结果有利于为锅炉故障诊断和运行优化提供更加准确的参考信息。
基金Project(2010CB732101)supported by the National Key Basic Research and Development Program of ChinaProjects(51079145,51379201)supported by the National Natural Science Foundation of China
文摘The pressure solution model of granular aggregates was introduced into a FEM code which was developed for the analysis of thermo-hydro-mechanical(T-H-M) coupling in porous medium. Aimed at creating a hypothetical model of nuclear waste disposal in unsaturated quartz aggregate rock mass with laboratory scale, two 4-year computation cases were designed: 1) The porosity and permeability of rock mass are functions of the pressure solution; 2) The porosity and the permeability are constants. Calculation results show that the magnitude and distribution of stresses in the rock mass of these two calculation cases are roughly the same. And, the porosity and the permeability decrease to 43%-54% and 4.4%-9.1% of their original values after case 1 being accomplished; but the negative pore water pressures in cases 1 and 2 are respectively 1.0-1.25 and 1.0-1.1 times of their initial values under the action of nuclear waste. Case 1 exhibits the obvious effect of pressure solution.
