Investigation the combined effects of exhaust gas recirculation (EGR) and alcohol-diesel blends in improvement of NOX-PM Trade-off in compression ignition (CI) diesel engine

The increasing demand to decrease the greenhouse gas emissions leads to find clean fuel and renewable fuel such as ethanol and methanol that good replacement of oil-derived transportation fuels. The combined effects of alcohols blends (ethanol-diesel and methanol-diesel) and with and without EGR on NOX-PM Trade-off in diesel engine were investigated under variable engine loads and speeds. The EGR is considered efficient technology to reduce the NOX emissions in compression ignition (CI) diesel engines. The current study highlighted on the trade-off between nitrogen oxides (NOX) and particulate matter (PM). The oxygenating content in the ethanol blend (E10) and methanol blend (M10) decrease the PM concentrations in the exhaust pipe compared to the diesel fuel for different engine operating conditions with keep NOX emissions in the moderate level. It was found that the NOX/PM concentrations significantly decreased from the combustion of E10 and M10 under variable engine loads and speeds.

Analysis of the NOx storage behaviour during cold start of modern SCR flow-through substrates and SCR on-filter substrates

Selective catalytic reduction (SCR) systems are the state-of-the-art technology to reduce nitrogen oxide emissions (NOx) of modern diesel engines. The system behaviour is well understood in the common temperature working area. However, the system properties below light-off temperature are less well known and offer a wide scope for further investigations. Vehicle measurements show that under specific conditions during cold start, NOx can be partially stored and converted on on-filter and flow-through SCR catalysts. The purpose of this work was in a first step to analyse the main influence parameters on the NOx storage behaviour. Therefore, synthetic gas test bench measurements have been carried out, varying the gas concentrations, temperature, and gas hourly space velocity (GHSV). These investigations showed that the NOx storage effect strongly depends on the NH3 level stored in the catalyst, GHSV, the adsorbed water (H2O) on the catalyst, and the temperature of the catalyst. Further influence parameters such as the gas composition with focus on carbon monoxide (CO), short-chain hydrocarbons and long-chain hydrocarbons have been analysed on a synthetic gas test bench. Depending on operating conditions, a significant amount of NOx can be stored on a dry catalyst during the cold start phase. The water vapor from the combustion condenses on the cold exhaust pipe during the first seconds, or up to a few minutes after a cold start. As the water vapor reaches the surface of the catalyst, it condenses and adsorbs onto it, leading to a sudden temperature rise. This exothermal reaction causes the stored NOx to be desorbed, and furthermore it is partially reduced by the NH3 stored in the catalyst.

Performance verification of heavy-duty motorcycles adjusting intake and exhaust timing

Heavy-duty locomotives with large exhaust vehicles have become a common means of transportation for Taiwanese. However, for car owners to increase power output, improve efficiency, and reduce fuel use, the original factory has designed demand settings for cost, environmental protection, and regulations. This leads to the sacrifice of the performance of the original car design, so the RC2 Super ECU is used to replace the original injection computer, and the air-fuel ratio, ignition angle and exhaust pipe are modified. Without the need to change the structure of the heavy locomotive, the horsepower of the heavy locomotive is improved. It is pointed out that the modification of these three original factory settings has greatly improved the overall speed performance of the heavy-duty locomotive horsepower. Therefore, it is proposed that “heavy locomotive performance verification by changing the timing of intake and exhaust” is mainly to verify the performance benefits and performance brought about by modifying the air-fuel ratio, ignition angle and exhaust pipe.

Overview of the main powertrain architectures for hybrid and electric vehicles

The research for alternative solutions to assist the propulsion, fuel converters and energy storage systems (ESS) in vehicular applications has become the focus of many institutions and mainly in the automotive industry, aiming to reduce the impacts caused by the emission of gases in the exhaust pipe and to improve energy efficiency in the worldwide vehicle fleet. Hybrid Electric Vehicles (HEV) and Electric Vehicles (EV) are currently a reality and meet this requirement to build a greener and less polluting society. In this context, this paper describes the operational characteristics of the different powertrain architectures employed in hybrid electric vehicles, including series, parallel and series-parallel topologies, as well as battery-powered and fuel cell electric vehicles. Finally, some of the elementary issues facing these advanced vehicular technologies, including the challenges for market penetration are highlighted.

Modeling and Integrated Optimization of Power Split and Exhaust Thermal Management on Diesel Hybrid Electric Vehicles

To simultaneously achieve high fuel efficiency and low emissions in a diesel hybrid electric vehicle (DHEV), it is necessary to optimize not only power split but also exhaust thermal management for emission aftertreatment systems. However, how to coordinate the power split and the exhaust thermal management to balance fuel economy improvement and emissions reduction remains a formidable challenge. In this paper, a hierarchical model predictive control (MPC) framework is proposed to coordinate the power split and the exhaust thermal management. The method consists of two parts: a fuel and thermal optimized controller (FTOC) combining the rule-based and the optimization-based methods for power split simultaneously considering fuel consumption and exhaust temperature, and a fuel post-injection thermal controller (FPTC) for exhaust thermal management with a separate fuel injection system added to the exhaust pipe. Additionally, preview information about the road grade is introduced to improve the power split by a fuel and thermal on slope forecast optimized controller (FTSFOC). Simulation results show that the hierarchical method (FTOC + FPTC) can reach the optimal exhaust temperature nearly 40 s earlier, and its total fuel consumption is also reduced by 8.9%, as compared to the sequential method under a world light test cycle (WLTC) driving cycle. Moreover, the total fuel consumption of the FTSFOC is reduced by 5.2%, as compared to the fuel and thermal on sensor-information optimized controller (FTSOC) working with real-time road grade information.

Computation on Infrared Radiation of Side Exhaust Plume under Spraying Water

The high temperature plume of ships has obvious infrared radiation feature. Spraying water-liquid droplets in side exhaust system can effectively reduce the high temperature of the tail gas to reduce the infrared radiation of the exhaust plume. In this paper, ANSYS Fluent is used to establish the concentration field and temperature field of the side exhaust plume atter spraying water-liquid droplets. And the statistic narrow band model (Malkmus model) and the C-G approximation method are used to calculate the infrared radiation intensity of the exhaust plume in the normal direction of the exhaust outlet from 3 to 5 μm on this basis. The final results show that spraying water-liquid droplets in side exhaust pipe can reduce the infrared radiation of the side exhaust plume from 3 to 5um by 88.9%% compared with the initial intensity; when the water flow reaches 0.7kg/s, infrared radiation intensity remains unchanged.

Study of the structure of gas flow іn a cyclone wіth іntermedіate dust removal

The works in which designs of the dust collectors, which are often used in the industry, are analyzed. It is shown that the efficiency of dust collectors largely depends on the structure of the gas flow in the apparatus. Based on the analysis of the current cyclone devices, a picture of the separation process is obtained, and the factors that negatively affect the operation of dust collectors are identified. It is established that forecasting the work of dust collecting devices in certain conditions is most effective to perform methods of numerical modeling and simulation of the separation process, which are widely used for the research of devices of this type. Using the methods of numerical simulation, the study of the cyclone with intermediate dust removal was carried out. In this cyclone, the change in the radius of the apparatus of the tangential, radial, and axial velocity components is investigated. In the course of the research, it is established that in the separation space the tangential component of velocity increases from 18–20 m/s in the upper part of the device to 22–25 m/s in the area of the lower end of the exhaust pipe, the radial component of velocity takes values from 0 to 2 m/s, and the axial component of the speed has a maximum value of 10–15 m/s. In the conical part of the apparatus the tangential component of velocity decreases from 27 m/s in the upper planes of the conical part of the apparatus to 10 m / s near the dust unloading pipe, the radial component of speed has centripetal character, the axial component of speed decreases as the gas flow to the dust unloading pipe decreases. It has been established that in the cylindrical part of the apparatus about 60 % of the gas flow volume is transferred from the downstream to the upstream by a secondary vortex, and in the conical part, about 40 % of the gas volume is transferred from the downstream to the upstream. It is shown that large values of the tangential component of velocity in the separation zone contribute to the ingress of dust particles into the annular space behind the dust unloading holes, and small values of the tangential component of velocity, axial and radial in the annular space behind the dust unloading holes has a positive effect on the operation of the dust collector.

MODELING OF THE PROCESS OF ELECTROMECHANICAL CONTROL OF GAS DISTRIBUTION OF AN ELECTRIC ENERGY GENERATOR WITH AN INTERNAL COMBUSTION ENGINE

The use of generators at different load levels allows you to use part of the rated power of the engines, by reducing the speed of the internal combustion engine, thus reducing fuel consumption and increase the overall efficiency of the system as a whole. However, it should be noted that the optimal operation of the internal combustion engine at fixed gas distribution parameters is possible only at a certain engine speed. Reducing the engine speed leads to a deterioration of the filling of the fuel-air mixture and the release of exhaust gases from the engine, accompanied by the intake of exhaust gases into the intake manifold and the emission of part of the fuel mixture into the exhaust pipe. The paper presents the results of the study of generator parameters and the general concept of creating an autonomous power supply control system based on an internal combustion engine in order to reduce the specific indicators of electricity generation. The expediency of regulating the power level of an internal combustion engine has been experimentally proved. To achieve this goal, it is proposed to adjust the opening and closing angles of the internal combustion engine with a solenoid valve. The use of this system allows to reduce the specific costs by more than 4 times when generating electricity with low generator load. Based on the phase distribution diagram of the internal combustion engine, the dependence of the change of the opening and closing angles of the inlet and outlet valves on the power of the autonomous energy source is proposed.