Analysis of exhaust gas flow through a particulate filter in the exhaust of the spark ignition direct injection engine

Synthesis gas (Syngas), a mixture of hydrogen and carbon monoxide, can be manufactured from natural gas, coal, petroleum, biomass, and even from organic wastes. It can substitute fossil diesel as an alternative gaseous fuel in compression ignition engines under dual fuel operation route. Experiments were conducted in a single cylinder, constant speed and direct injection diesel engine fuelled with syngas-diesel in dual fuel mode. The engine is designed to develop a power output of 5.2 kW at its rated speed of 1500 rpm under variable loads with inducted syngas fuel having H2 to CO ratio of 1:1 by volume. Diesel fuel as a pilot was injected into the engine in the conventional manner. The diesel engine was run at varying loads of 20, 40, 60, 80 and 100%. The performance of dual fuel engine is assessed by parameters such as thermal efficiency, exhaust gas temperature, diesel replacement rate, gas flow rate, peak cylinder pressure, exhaust O2 and emissions like NOx, CO and HC. Dual fuel operation showed a decrease in brake thermal efficiency from 16.1% to a maximum of 20.92% at 80% load. The maximum diesel substitution by syngas was found 58.77% at minimum exhaust O2 availability condition of 80% engine load. The NOx level was reduced from 144 ppm to 103 ppm for syngas-diesel mode at the best efficiency point. Due to poor combustion efficiency of dual fuel operation, there were increases in CO and HC emissions throughout the range of engine test loads. The decrease in peak pressure causes the exhaust gas temperature to rise at all loads of dual fuel operation. The present investigation provides some useful indications of using syngas fuel in a diesel engine under dual fuel operation.

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Identification of character of flow realized in low power heating boilers

E3S Web of Conferences ◽

10.1051/e3sconf/201912801008 ◽

2019 ◽

Vol 128 ◽

pp. 01008

Author(s):

Wojciech Judt ◽

Bartosz Ciupek ◽

Rafał Urbaniak

Keyword(s):

Heat Transfer ◽

Low Power ◽

Transfer Process ◽

Gas Flow ◽

Heat Transfer Process ◽

Vertical Position ◽

Exhaust Gas ◽

Flow Through ◽

Heating Boiler ◽

Different Levels

An analysis of a heat transfer process during exhaust gas flow through two boiler draughts connected in the reversing chamber is presented. The article shows the main differences in the exhaustgas flowthrough the boiler construction when heating boiler works with different levels of heating power.The aim of the proposed research is defining a character of a flow and a heat transfer process depending onthe horizontal and vertical position of boiler draughts.

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Cold-Start Computational Fluid Dynamics Simulation of Spark-Ignition Direct-Injection Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4039729 ◽

2018 ◽

Vol 140 (11) ◽

Author(s):

Xiaofeng Yang ◽

Tang-Wei Kuo ◽

Kulwinder Singh ◽

Rafat Hattar ◽

Yangbing Zeng

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Engine Speed ◽

Direct Injection ◽

Cold Start ◽

Spark Ignition ◽

Dynamics Simulation ◽

Residual Fraction ◽

Direct Injection Engine ◽

Start Process

Reliably starting the engine during extremely cold ambient temperatures is one of the largest calibration and emissions challenges in engine development. Although cold-start conditions comprise only a small portion of an engine's typical drive cycle, large amounts of hydrocarbon and particulate emissions are generated during this time, and the calibration of cold-start operation takes several months to complete. During the cold start period, results of previous cycle combustion event strongly influences the subsequent cycle due to variations in engine speed, residual fraction, residual wall film mass, in-cylinder charge and wall temperatures, and air flow distribution between cylinders. Including all these parameters in computational fluid dynamics (CFD) simulation is critical in understanding the cold start process in transient and cumulative manner. Measured cold start data of a production of four-cylinder spark-ignition (SI) direct-injection engine were collected for this study with an ambient temperature of −30 °C. Three-dimensional (3D) transient engine flow, spray, and combustion simulation over first three consecutive engine cycles is carried out to provide a better understanding of the cold-start process. Measured engine speed and one-dimensional (1D) conjugate heat transfer (CHT) model is used to capture realistic in-cylinder flow dynamics and transient wall temperatures for more accurate fuel–air mixing predictions. The CFD predicted cumulative heat release trend for the first three cycles matches the data from measured pressure analysis. The same observation can be made for the vaporized fuel mass as well. These observations are explained in the report.

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