Browse Topic: HCCI engines
The combustion timing of auto-ignited combustion is determined by composition, temperature, and pressure of cylinder charge. Thus, for a successful auto-ignition, those key variables must be controlled within tight target ranges, which is challenging due to (i) nature of coupling between those variables, and (ii) complexity of managing multiple actuators in the engine. In this article, a control strategy that manages multiple actuators of a boosted homogeneous charge compression ignition (HCCI) engine is developed to maintain robust auto-ignited combustion. The HCCI engine being considered is equipped with multiple boosting devices including a supercharger and a turbocharger in addition to conventional actuators and sensors. Since each boosting device has its own pros and cons, harmonizing those boosting devices is crucial for successful transient operation. To address the multi-variable transient control problem, speed-gradient control methodology is applied to minimize coupling
Letter from the Special Issue Editors
In this work neural network models are used to reconstruct in-cylinder pressure from a vibration signal measured from the engine surface by a low-cost accelerometer. Using accelerometers to capture engine combustion is a cost-effective approach due to their low price and flexibility. The paper describes a virtual sensor that re-constructs the in-cylinder pressure and some of its key parameters by using the engine vibration data as input. The vibration and cylinder pressure data have been processed before the neural network model training. Additionally, the correlation between the vibration and in-cylinder pressure data is analyzed to show that the vibration signal is a good input to model the cylinder pressure.The approach is validated on a RON95 single cylinder research engine realizing homogeneous charge compression ignition (HCCI). The experimental matrix covers multiple load/rpm steady-state operating points with different start of injection and lambda setpoints. A radial basis
Carbon Capture and Storage (CCS) techniques in combination with oxy-fuel combustion have been applied as an effective way to achieve nitrogen-free combustion and zero-carbon emissions. The present study has been carried out computationally in the framework of a European project (RIVER) (funded by Interreg North-West Europe) to explore the effect of intake charge temperature on oxy-fuel combustion in an HSDI diesel engine under HCCI combustion mode. Experimental data obtained from a Ford Puma common-rail diesel engine for a conventional part-load condition at 1500 rev/min and 6.8 bar IMEP have been used to validate the CFD model. To simulate the combustion process of HCCI, a reduced chemical n-heptane-n-butanol-PAH model has been adopted. The model has 349 elementary reactions and 76 species. The simulation has been carried out at five different intake charge temperatures (140°C, 160°C, 180°C, 200°C, and 220°C) and five different intake oxygen percentages (15%, 17%, 19%, and 21% v/v
Low Temperature Combustion (LTC) is an emerging technology that offers an alternative to conventional spark and compression ignition. A highly discussed LTC mode is homogeneous charge compression ignition (HCCI), which consists in a combustion of a highly diluted well-mixed charge at the end of compression stroke, when the charge reaches the auto-ignition state. Since HCCI is an LTC mode, it can result in low NOX emissions with an indicated efficiency comparable to a diesel engine. Otherwise, there are some challenges to overcome such as achieving high loads without knocking and combustion timing control. Several methods to control the combustion had been investigated, between them, the injection of water may be useful to extend HCCI knock free operation and to enable combustion phasing control. This work investigated the influence of water injection in the intake of an ethanol HCCI cylinder from a converted diesel generator set. The EGR, used in HCCI, was obtained via total
Items per page:
50
1 – 50 of 1192