Development of Surrogate Model for Oxygenated Wide-Distillation Fuel with Polyoxymethylene Dimethyl Ether
Development of Surrogate Model for Oxygenated Wide-Distillation Fuel with Polyoxymethylene Dimethyl Ether
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DOI：
10.4271/2017-01-2336
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发表时间：
2017-11-01
影响因子：
1
通讯作者：
Wang, Zhi
中科院分区：
文献类型：
--
作者：
He, Tanjin;Liu, Hao-Ye;Wang, Zhi
聚甲醛二甲醚（PODEn）具有独特的化学结构（CH_3 O [CH_2 O]（n）CH_3，n ≥ 2）和高十六烷值，是一种很有前途的绿色柴油添加剂。与具有降低车辆燃料生产成本的吸引力潜力的一般宽馏分燃料（WDF）一起，具有PODEn的含氧WDF可以帮助同时实现高效率和低碳烟、NOx、HC和CO排放。本文首次提出了描述PODE 1和PODE 3低温点火特性的详细反应机理（225个组分，1082个反应）。为了验证这一机理，利用快速压缩机（RCM）进行了准均相实验，测量了不同有效温度下的点火延迟时间（600 K - 1000 K），用于四种不同的PODE 1/O-2/N-2/Ar混合物（phi=0.25，O-2：Ar=1：5; phi=0.5，O-2：Ar：N-2 = 1：2.5：2.5; phi=1.0，O-2：Ar：N-2 = 1：2.5：2.5; phi=1.0，O-2：Ar：N-2 = 1：5：5）和两种不同的有效压力（10巴，19巴）。在一台自然吸气单缸HCCI研究发动机上，以PODE 3质量分数为88.9%的PODEn（n=1-4）混合气为燃料，在1600 r/min、充量当量比为0.4、废气再循环率为42%的工况下进行了HCCI燃烧试验，以反映真实的发动机工况。利用我们新开发的PODE 1和PODE 3机制，在实验数据和模拟结果的比较中取得了很好的一致性。考虑到PODEn在柴油机中更频繁地用作调合组分的事实，用PODEn（包括替代物如PODE 3、正庚烷、异辛烷等）对含氧WDF进行了简化的多组分机理（354个组分，943个反应）。在1600 r/min、平均指示压力0.8 MPa、EGR率25%的条件下，以含氧WDF（汽油/柴油/PODEn混合气）为燃料，进行了直喷压燃（DICI）发动机试验。该替代模型将有助于掺混PODEn的含氧WDF的设计，以及使用含氧WDF的发动机的燃烧和排放特性的预测。
Polyoxymethylene Dimethyl Ether (PODEn) is a promising green additive to diesel fuel, owing to the unique chemical structure (CH3O[CH2O](n)CH3, n >= 2) and high cetane number. Together with the general wide-distillation fuel (WDF), which has an attractive potential to reduce the cost of production of vehicle fuel, the oxygenated WDF with PODEn can help achieve a high efficiency and low emissions of soot, NOx, HC, and CO simultaneously. In this paper, the first detailed reaction mechanism (225 species, 1082 reactions) which can describe the ignition characteristics of PODE1 and PODE3 at low temperature was developed. To validate this mechanism, rapid compression machine (RCM) was used to conduct the quasi-homogeneous experiments to measure the ignition delay time at various effective temperatures (600 K - 1000 K) for four different PODE1/O-2/N-2/Ar mixture (phi=0.25, O-2:Ar=1:5; phi=0.5, O-2:Ar:N-2 = 1:2.5:2.5; phi=1.0, O-2:Ar:N-2 = 1:2.5:2.5; phi=1.0, O-2:Ar:N-2 = 1:5:5) and two different effective pressures (10 bar, 19 bar). Homogeneous Charge Compression Ignition (HCCI) experiments fueled with PODEn (n=1-4) mixture, in which the mass fraction of PODE3 is about 88.9% were also conducted in a naturally aspirated single-cylinder HCCI research engine at 1600 r/min, 0.4 charge-mass equivalence ratio, and 42% exhaust gas recirculation (EGR) to take the real engine working condition into consideration. Good agreement was achieved in the comparison of the experimental data and the simulation results utilizing our newly developed mechanism for PODE1 and PODE3. Considering the fact that PODEn is more frequently used as a blending component in diesel engine, a reduced multicomponent mechanism (354 species, 943 reactions) for oxygenated WDF with PODEn (covering surrogates like PODE3, n-heptane, iso-octane, etc.) was developed and then validated with Direct-Injection Compression Ignition (DICI) engine experiments fueled with oxygenated WDF (gasoline/diesel/PODEn mixture) at 1600 r/min, 0.8 MPa indicated mean effective pressure (IMEP), and 25% EGR. This surrogate model will contribute to the design of oxygenated WDF by blending PODEn, and to the prediction of the combustion and emission characteristics of engines using oxygenated WDF.