Žvar Baškovič Urban, Katrašnik Tomaž, Faussone Gian Claudio, Grilc Miha, Seljak Tine
University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva Cesta 6, SI-1000, Slovenia.
University of Nova Gorica, Vipavska 13, SI-5000, Nova Gorica, Slovenia; Sintol, Corso Matteotti 32A, 10121, Torino, Italy.
J Environ Manage. 2023 Oct 15;344:118711. doi: 10.1016/j.jenvman.2023.118711. Epub 2023 Aug 10.
Emission standards in European Union, designed to reduce the environmental impact of power generation, present a significant challenge for fast-response distributed power generation systems based on internal combustion engines. Regulated emissions, such as NO and particulate matter present a major concern due to their adverse number of environmental and health effects. Simultaneously, European Union strives towards sustainable management of plastic waste and seeks the ways for its upcycling and production of new fuels and chemicals. As an answer to the presented challenges, the present experimental study addresses the potential for use of chemically stabilized Waste Plastics Oil (WPO), a product of pyrolysis process of waste plastics in a Reactivity Controlled Compression Ignition (RCCI) combustion concept. To establish a reactivity-controlled combustion, the study uses a combination of methane (a model fuel for biomethane) and WPO to a) simultaneously reduce NO and particulate matter emissions due to low local combustion temperatures and a high degree of charge homogenization and b) address waste and carbon footprint reduction challenges. Through experiments, influence of direct injection timing and energy shares of utilized fuels to in-cylinder thermodynamic parameters and engine emission response were evaluated in engine operating points at constant indicated mean effective pressure. Acquired results were deeply investigated and benchmarked against compression ignition (CI) and RCCI operation with conventional diesel fuel to determine potential for WPO utilization in an advanced low-temperature combustion concept. Results show that chemically stabilized WPO can be efficiently utilized in RCCI combustion concept without adaptation of injection parameters and that with suitable control parameters, ultra-low emissions of NO and PM can be achieved with utilized fuels. For diesel/methane mix, NO and PM emissions were reduced compared to conventional CI operation for 82.0% and 93.2%, respectively, whereas for WPO/methane mix, NO and PM emissions were reduced for 88.7% and 97.6%, respectively, which can be ascribed to favourable chemical characteristics of WPO for the utilized combustion concept. In the least favourable operating point among those studied, indicated mean effective pressure covariance was kept below 2.5%, which is well below 5% being considered the limit for stable engine operation.
欧盟的排放标准旨在降低发电对环境的影响，这对基于内燃机的快速响应分布式发电系统构成了重大挑战。诸如氮氧化物和颗粒物等受监管的排放物因其对环境和健康的诸多不利影响而备受关注。与此同时，欧盟致力于塑料废物的可持续管理，并寻求对其进行升级再造以及生产新燃料和化学品的方法。作为应对上述挑战的举措，本实验研究探讨了在反应控制压缩点火（RCCI）燃烧概念中使用化学稳定的废塑料油（WPO）的潜力，WPO是废塑料热解过程的产物。为了实现反应控制燃烧，该研究使用甲烷（生物甲烷的模型燃料）和WPO的组合，以：a）由于局部燃烧温度低和混合气高度均匀而同时减少氮氧化物和颗粒物排放；b）应对废物和减少碳足迹的挑战。通过实验，在恒定指示平均有效压力下的发动机工况点，评估了直接喷射正时和所用燃料的能量份额对缸内热力学参数和发动机排放响应的影响。对获得的结果进行了深入研究，并与使用传统柴油燃料的压缩点火（CI）和RCCI运行进行了对比，以确定在先进低温燃烧概念中使用WPO的潜力。结果表明，化学稳定的WPO无需调整喷射参数即可在RCCI燃烧概念中有效利用，并且通过合适的控制参数，使用的燃料可实现超低的氮氧化物和颗粒物排放。对于柴油/甲烷混合气，与传统CI运行相比，氮氧化物和颗粒物排放分别降低了82.0%和93.2%，而对于WPO/甲烷混合气，氮氧化物和颗粒物排放分别降低了88.7%和97.6%，这可归因于WPO对于所用燃烧概念具有有利的化学特性。在所研究的最不利工况点，指示平均有效压力协方差保持在2.5%以下，远低于被视为发动机稳定运行极限的5%。
