共查询到18条相似文献,搜索用时 171 毫秒
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使用乙醇还原剂的NOx-SCR催化剂的性能评价 总被引:1,自引:0,他引:1
采用计算机辅助分析的方法设计了乙醇还原剂添加装置,并使用这套装置在发动机台架上进行了稀燃NOx选择催化还原(SCR)催化剂的性能评价试验.试验结果表明,在30000h-1空速、排温为350
420℃范围的条件下,该催化剂的NOx转化率维持在90%以上,而在低温和高温下的转化率较低;随着乙醇添加量的增加,催化剂NOx转化率提高,但同时会增加THC排放;当空速超过40000h-1后,催化剂性能有所下降. 相似文献
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研制的半合成油型和加H2 处理基础油型 10W 4 0CD+ 柴油机机油 ,通过了CD级柴油机机油国际标准发动机台架试验和大功率高速柴油机耐久性考核试验 ,很好地满足了高增压中冷大功率高速柴油机的使用要求。大功率高速柴油机拆检结果表明 ,发动机积炭少 ,各对摩擦副磨损小。具有一定分水性能的柴油机机油通过了Cat.1K国际标准发动机台架试验 ,表明可以用国内高性能发动机试验评定具有国际先进水平的发动机机油 相似文献
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《汽车科技》2019,(6)
选择性催化还原技术(SCR)是国六柴油机控制NO_x排放的主要技术,为了对比国外后处理厂家和国内后处理厂家的铜基分子筛SCR催化剂性能,搭建了SCR催化剂的小样测试台架,对两种SCR催化剂进行了小样性能测试分析,包括稳态测试,瞬态测试,并介绍了相应的测试流程方法。测试内容覆盖了温度扫描,空速扫描,氨氮比扫描,NO/NO_x比例扫描,NO氧化效率,标准SCR转化效率,氨氧化效率和氨存储。试验结果表明,两种催化剂在不同试验条件下所呈现的性能变化规律基本一致,国外催化剂的NO_x转化效率比国内催化剂高3%左右,200℃条件下国外催化剂的氨存储量比国内催化剂高0.5g/L,两种催化剂的性能差异主要集中在低温区域。 相似文献
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In this study, NOx conversion characteristics of a urea selective catalytic reduction (SCR) system equipped on a heavy-duty diesel engine were evaluated through engine dynamometer bench tests over a scheduled world harmonized transient cycle (WHTC). Also, based on transient SCR simulations, the thermal management strategy to improve SCR NOx conversion efficiency was investigated. As a result, it was found that a selective increase in exhaust temperature at low temperature period would be a useful measure to increase SCR efficiency on WHTC mode. From the baseline SCR efficiency of around 98 % on WHTC mode, the current simulation results have shown that around 99 % level of SCR efficiency would be achievable by increasing exhaust temperatures with modifying diesel exhaust fluid (DEF) dosage. Another valuable contribution of this study is that the design guidelines for controlling exhaust temperature and DEF injection to obtain a target NOx conversion efficiency are presented for SCR systems of heavy-duty diesel engines on transient operating conditions. 相似文献
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-Recently, regulation of NOx and PM emission in diesel engines has become stricter and the EGR system has been expanded into a dual loop EGR system to increase EGR rate as well as to utilize exhaust gas strategically. In terms of engine combustion characteristics, burnt gas fraction is becoming an important factor of solving the NOx and PM emission reduction problem more efficiently but conventional controller focused only pressure and air flow rate targets. Unlike the previous studies, this paper describes a model based burnt gas fraction control structure for a diesel engine with a dual loop EGR and a turbocharger. Feedforward control inputs based on burnt gas fraction states aids in the precise control of diesel engines, especially in transient states by considering coupled behavior within the system. For the controller validation, a control oriented reduced order model of a diesel engine air management system is established to simplify the control input computation and its stability is proved by analysing the internal dynamics stability. Then, a sliding mode controller is designed and controller robustness at certain operating points is validated using an HiLS bench. 相似文献
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基于高阶滑模混沌控制的快速稳定和高效鲁棒特点,建立了柴油机EGR系统动态数学模型;设计了柴油机EGR系统的误差评估滑模面、滑模控制率与混沌控制器;针对EGR阀动态控制规律与响应迟滞机理,制订了柴油机EGR阀的控制、修正与优化策略。利用Control Core软件,对EGR阀的响应特性、占空比和EGR率进行了仿真,实现了高阶滑模混沌控制器对EGR系统精确修正、优化与控制。依据柴油机瞬态测试循环法规,进行了增压柴油机EGR系统的动态响应特性和排放测试等试验。试验结果表明,该高阶滑模混沌控制器性能可靠、处理能力强、控制精度高,满足柴油机EGR系统的控制要求。 相似文献