Towards Model-Based Control of RCCI-CDF Mode-Switching in Dual Fuel Engines
Towards Model-Based Control of RCCI-CDF Mode-Switching in Dual Fuel Engines
复制标题
双燃料发动机中基于模型的 RCCI-CDF 模式切换控制
DOI：
10.4271/2018-01-0263
复制
发表时间：
2018
影响因子：
4.9
通讯作者：
F. Willems
中科院分区：
文献类型：
--
作者：
A. Indrajuana;C. Bekdemir;E. Feru;F. Willems
与单模运行相比，使用燃烧模式切换的双燃料内燃机的运行具有更高的热效率。对于各种燃料组合，发动机研究界已经表明，在反应性控制压缩点火（RCCI）模式下运行双燃料发动机，与传统的双燃料（CDF）操作相比，是进一步提高热效率的可行方法。在RCCI燃烧中，也有超低的发动机NOx和烟尘排放的报道。然而，取决于可用的硬件，稳定的RCCI燃烧仅限于一定的负载范围和操作条件。因此，模式切换是短期内实现RCCI的一种很有前途的方法。本文提出了一种基于模型的双燃料模式切换控制器的开发方法。仿真结果证明了该控制器在天然气和柴油重型发动机上的应用潜力。将现有的面向控制的发动机模型扩展为新的CDF模型，以模拟CDF和RCCI的运行。该模型与实验数据吻合较好。作为基于模型的控制发展的第一步，该扩展模型用于系统分析，以了解切换行为并设计协调的空气-燃料路径控制器。该闭环控制器将静态解耦与下一周期CA50-IMEP-Blend Ratio控制相结合。对于低负荷工作点的模式切换序列，闭环控制发动机表现出稳定的行为和良好的参考跟踪。最后展望了将基于模型的多缸发动机双燃料模式切换控制策略应用于道路的必要步骤。
The operation of a dual fuel combustion engine using combustion mode-switching offers the benefit of higher thermal efficiency compared to single-mode operation. For various fuel combinations, the engine research community has shown that running dual fuel engines in Reactivity Controlled Compression Ignition (RCCI) mode, is a feasible way to further improve thermal efficiency compared to Conventional Dual Fuel (CDF) operation of the same engine. In RCCI combustion, also ultra-low engine-out NOx and soot emissions have been reported. Depending on available hardware, however, stable RCCI combustion is limited to a certain load range and operating conditions. Therefore, mode-switching is a promising way to implement RCCI in practice on short term. In this paper, a model-based development approach for a dual fuel mode-switching controller is presented. Simulation results demonstrate the potential of this controller for a heavyduty engine running on natural gas and diesel. An existing control-oriented engine model is extended with a new CDF model to simulate both CDF and RCCI operation. This model shows good agreement with experimental data. As a first step towards model-based control development, this extended model is used for system analysis to understand the switching behavior and to design a coordinated air-fuel path controller. This closed-loop controller combines static decoupling with next-cycle CA50-IMEP-Blend Ratio control. For a modeswitching sequence in a low load operating point, the closedloop controlled engine demonstrates stable behavior and good reference tracking. The paper concludes with an outlook on necessary steps to bring model-based control strategies for dual fuel mode-switching in a multi-cylinder engine on the road.