Chemical engineers testing methods to improve efficiency of diesel engines while maintaining performance are getting help from a summer staple: Tiki torches.
Notre Dame大学的工程师团队正在使用后院火炬作为模拟柴油发动机中烟灰氧化过程的一部分 - 当柴油机中的烟灰收集在颗粒过滤器的壁中并且必须被烧掉- 根据最近发表的一项研究Catalysts。
“This study is part of an effort over many years in which we have discovered and developed low-cost catalysts for soot oxidation that are based on silica glass,” said Paul McGinn, a co-lead author of the study and professor in the Department of Chemical and Biomolecular Engineering at Notre Dame.
McGinn和Canumins Inc.的Cangsheng Su在Cummins Inc.中展开了一种用二氧化硅玻璃涂上柴油颗粒过滤器的方法，该方法缓慢释放钾离子。钾用作催化剂，降低引发过滤器再生或烟灰氧化所需的温度 - 以提高效率。
他们所需要的是模拟现实世界驾驶条件的简单方法，包括通过柴油微粒过滤器的连续流动。
“We could do it continuously using the Tiki torch, using the Tiki soot as a surrogate for real engine soot,” McGinn said. “Depending on the setting, you really get a lot of soot coming off of it, which is what we want.” The team constructed a sophisticated reactor equipped with soot generator and backpressure sensors, which allows them to control conditions including oxygen rates, air-to-fuel ratios and soot production per hour.
降低烟灰氧化的新方法对柴油发动机制造商特别感兴趣。柴油排气含有烟灰颗粒和氮氧化物（NOx），烟灰是全球变暖的主要因素和呼吸问题的原因。环保局（EPA）一直致力于减少车辆，工业车辆，机车和船舶的排放超过十多年。
For diesel engine vehicles, the EPA requires both soot and NOx be kept below certain levels but challenges remain to reducing those emissions economically without sacrificing performance. When the engine’s operating conditions are adjusted to emit low levels of NOx, soot levels increase, and vice versa.
标准柴油颗粒过滤器是具有蜂窝状结构和多孔壁的陶瓷圆筒。滤波器的每个其他通道或打开 - 关闭。随着排气进入过滤器，烟灰沿着内壁收集，如清洁的排气通过。
To burn off soot buildup along the filter walls, exhaust temperatures need to reach 600 degrees Celsius (1,112 F). “When you’re in an urban environment where you’re stopping and starting your engine, the exhaust temperature doesn’t get that hot,” McGinn said.
In some cases, fuel is used to heat up the filter and burn off the soot — a process called active regeneration — which delivers a hit the vehicle’s fuel mileage and requires substantial noble metal (such as platinum) usage.
“Everyone is looking for a low-cost way to get the temperature down,” McGinn said. “In our case, we’ve developed an inexpensive glass coating that’s one to two microns thick and apply it to the diesel particulate filters. The glass delivers a potassium catalyst slowly over 150,000 miles of driving and allows for what’s called passive regeneration. So when you’re out on the highway at high speed, the exhaust temperature gets high enough to burn off soot buildup continuously.”
使用Tiki火炬提供测试所需的烟灰堆积，McGinn表示，他的团队将研究如何进一步量身定制玻璃组合物，也可以减少NOx。
提起：快速原型设计那Sensors (pressure)
