排序方式: 共有49条查询结果,搜索用时 15 毫秒
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温度对耗氧型惰化系统产水性能影响 总被引:2,自引:0,他引:2
以油箱出口气体的摩尔流量为基准,推导了流经催化反应器、冷却器前后各气体组分的摩尔流量关系,建立了耗氧型惰化系统的数学模型。研究了环境温度对系统中“水”性能的影响。结果表明:随着惰化的进行,油箱上部水蒸气占比逐渐增加,而冷却气体量、反应器出口相对湿度及中除水量逐渐降低;液态水析出对冷却气体量影响巨大,不能忽略;另外,系统中水的生成与析出与环境温度相关,且环境温度越低,油箱水蒸气体积分数上升越慢,但系统需要的冷却空气量越多且析出的液态水量越大,如环境温度为0 ℃时,冷却器中所需冷却气体量分别约为20、40 ℃时的111倍、126倍。因此在设计耗氧型惰化系统时,应充分考虑温度变化对水的生成与析出的影响。 相似文献
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为了掌握低排放燃烧室的污染物排放情况,对其化学反应网络器(CRN)模型的参数化进行研究.对爬升工况下燃烧室CFD数值模拟结果进行分析,划分燃烧室的结构,得到燃烧室的CRN模型.再利用自编程软件对燃烧室的结构参数和进口参数进行参数化定义,并把参数化的CRN模型在不同工况下的模拟结果与试验结果分别比较.结果表明:在慢车工况下二者相差不大,在爬升工况下二者差异也在允许误差范围之内.验证了该模型可行性较好,该参数化CRN模型可用于预测低排放燃烧室的污染物排放量和出口温度. 相似文献
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通过CFD方法建立了一个耦合化学反应的多孔介质二维拟均相反应器模型,研究了耗氧型惰化系统在不同工况下反应器的操作范围及工作性能。以RP-3燃油为研究对象,采用Fluent 17.0软件的多孔介质单温度模型,通过UDS (User Defined Scalar)添加固相能量方程,采用源项形式添加化学反应热到固相能量方程。研究了不同参数对反应器起燃过程的影响,并给出了起燃过程内反应器催化床温度的变化过程。结果显示:反应器起燃过程中,催化床温度十分不均匀;RP-3摩尔分数的增加可大幅度缩短起燃时间,并且可降低起燃温度;存在一个适宜的气体速度使得反应器能够快速起燃。 相似文献
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Franz Kenn 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Due to high resupply costs, especially for long-duration stays in space habitats beyond low earth orbit, future manned space missions will require life support systems (LSS) with a high degree of regenerativity. Possible ways to overcome the waste of resources and to save on resupply mass are therefore of major interest for the development of next generation environmental control and life support systems. 相似文献
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高压直流输电晶闸管阀用饱和电抗器的设计 总被引:1,自引:0,他引:1
高压直流换流阀用饱和电抗器的作用是抑制流经晶闸管的电流变化率,限制晶闸管产生的电压,提高晶闸管换流阀分布电压的均匀性。主要研究高压直流换流阀用饱和电抗器的理论设计、结构排布及线圈选取等方法,具有一定的实际应用价值。 相似文献
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CFD predictions of LBO limits for aero-engine combustors using fuel iterative approximation 总被引:1,自引:0,他引:1
Lean blow-out (LBO) is critical to operational performance of combustion systems in propulsion and power generation. Current predictive tools for LBO limits are based on decadesold empirical correlations that have limited applicability for modern combustor designs. According to the Lefebvre’s model for LBO and classical perfect stirred reactor (PSR) concept, a load parameter (LP) is proposed for LBO analysis of aero-engine combustors in this paper. The parameters contained in load parameter are all estimated from the non-reacting flow field of a combustor that is obtained by numerical simulation. Additionally, based on the load parameter, a method of fuel iterative approximation (FIA) is proposed to predict the LBO limit of the combustor. Compared with experimental data for 19 combustors, it is found that load parameter can represent the actual combustion load of the combustor near LBO and have good relativity with LBO fuel/air ratio (FAR). The LBO FAR obtained by FIA shows good agreement with experimental data, the maximum prediction uncertainty of FIA is about ±17.5%. Because only the non-reacting flow is simulated, the time cost of the LBO limit prediction using FIA is relatively low (about 6 h for one combustor with computer equipment of CPU 2.66 GHz · 4 and 4 GB memory), showing that FIA is reliable and efficient to be used for practical applications. 相似文献
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