Evaluation of thermal barrier coatings and surface roughness in a single-cylinder light-duty diesel engine
Evaluation of thermal barrier coatings and surface roughness in a single-cylinder light-duty diesel engine
复制标题
单缸轻型柴油机热障涂层和表面粗糙度的评估
DOI：
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复制
发表时间：
2019
影响因子：
2.5
通讯作者：
I. Denbratt
中科院分区：
文献类型：
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作者：
Joop Somhorst;M. Oevermann;M. Bovo;I. Denbratt
在一台单缸轻型柴油机上研究了两种热障涂层及其表面粗糙度对传热、燃烧和排放的影响。评价的热障涂层材料是等离子喷涂氧化钇稳定的氧化锆和硬质阳极氧化铝，它们被施加在活塞顶表面上。研究的主要工具是高压循环的汽缸压力分析，从该分析中得出表观放热率、指示效率和热损失。为了验证计算的壁热传递，也测量了流向活塞冷却油的热流。热障涂层的应用可以影响发动机的工作条件，如充电温度和点火延迟。因此，特别注意选择稳定和可重复的发动机工作点。使用多元线性回归对实验数据进行建模，以隔离涂层和表面粗糙度的影响。研究结果表明，高表面粗糙度会导致壁面热损失增加和燃烧延迟。然而，这些影响在较低的发动机负荷和在烟灰沉积物的存在下不太明显。两种热障涂层都显示出循环平均壁热损失的减少，但指示效率没有改善。表面粗糙度和热障涂层对碳氢化合物排放有显著影响，特别是在发动机低负荷运行时，而对其他排放的影响相对较小。
The effect of two thermal barrier coatings and their surface roughness on heat transfer, combustion, and emissions has been investigated in a single-cylinder light-duty diesel engine. The evaluated thermal barrier coating materials were plasma-sprayed yttria-stabilized zirconia and hard anodized aluminum, which were applied on the piston top surface. The main tool for the investigation was cylinder pressure analysis of the high-pressure cycle, from which the apparent rate of heat release, indicated efficiency, and heat losses were derived. For verification of the calculated wall heat transfer, the heat flow to the piston cooling oil was measured as well. Application of thermal barrier coatings can influence engine operating conditions like charge temperature and ignition delay. Therefore, extra attention was paid to choosing stable and repeatable engine operating points. The experimental data were modeled using multiple linear regression to isolate the effects of the coatings and of the surface roughness. The results from this study show that high surface roughness leads to increased wall heat losses and a delayed combustion. However, these effects are less pronounced at lower engine loads and in the presence of soot deposits. Both thermal barrier coatings show a reduction of cycle-averaged wall heat losses, but no improvement in indicated efficiency. The surface roughness and thermal barrier coatings had a significant impact on the hydrocarbon emissions, especially for low-load engine operation, while their effect on the other exhaust emissions was relatively small.