Comparison of combustion characteristics and brake thermal efficiency of a heavy-duty diesel engine fueled with diesel and biodiesel at high altitude

Abstract Diesel engines are the predominant power source in trucking industry. Heavy duty trucks move more than 70% of all goods transported around the United States. The atmospheric conditions vary with altitude but are vital to diesel engine performance, efficiency, and emissions. Existing studies reported reduced thermal efficiency and increased emissions when truck engines were operated at high altitude. As the heat loss is a key parameter related to engine efficiency, the goal of this paper was to investigate the altitude impacts on in-cylinder heat transfer characteristics. A single cylinder four-stroke heavy duty diesel engine was performed at constant speed and load but different intake pressure to simulate the varying atmospheric conditions at different altitude. The engine raised the amount of diesel mass injected to the cylinder per cycle to maintain the identical power output under decreased atmospheric pressure and to compensate the combustion deterioration happened inside the cylinder. The experimental results indicated a higher bulk temperature at high altitude due to a smaller amount of mixture mass trapped inside the cylinder. Such a larger temperature difference between the hot products and the cold walls increased in-cylinder heat transfer to the coolant, especially during the combustion period. Specifically, a rise in 2000m altitude resulted in up to ∼2% increment in heat loss to the atmosphere per fired cycle. As a result, applying thermal coating to improve fuel economy is more necessary in high altitude states, such as Colorado and Wyoming.

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Effect of injection pressure and fuel mass on wall-impinging ignition and combustion characteristics of heavy-duty diesel engine at low temperatures

Fuel ◽

10.1016/j.fuel.2021.120904 ◽

2021 ◽

Vol 299 ◽

pp. 120904

Author(s):

Zhicheng Shi ◽

Han Wu ◽

Haiying Li ◽

Lu Zhang ◽

Xiangrong Li ◽

...

Keyword(s):

Diesel Engine ◽

Low Temperatures ◽

Injection Pressure ◽

Combustion Characteristics ◽

Heavy Duty ◽

Fuel Mass ◽

Heavy Duty Diesel Engine ◽

Heavy Duty Diesel ◽

Ignition And Combustion

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Turbocharging of a Heavy Duty Diesel Engine for a Specific Power and Performance Enhancement

Volume 6A: Energy ◽

10.1115/imece2015-53635 ◽

2015 ◽

Cited By ~ 1

Author(s):

Kareem Emara ◽

Ahmed Emara ◽

Elsayed Abdel Razek

Keyword(s):

Diesel Engine ◽

Direct Injection ◽

Combustion Characteristics ◽

Specific Power ◽

Heavy Duty ◽

Direct Injection Diesel Engine ◽

Engine Simulation ◽

Brake Power ◽

Heavy Duty Diesel Engine ◽

Heavy Duty Diesel

Increase of the capacity of heavy duty diesel engines is of great interest in the way of power enhancement in many engine applications. Turbocharger is one of the most important ways used to increase the engine specific power. The present study aimed to develop an analytical model to simulate the performance and combustion characteristics of a direct injection diesel engine. This model depends on the basic conservation equations of continuity, momentum and energy as well as equation of state, these equations are solved together numerically by using two steps Lax-Wendroff scheme. To address this, a comprehensive computer “FORTRAN” code was developed and applied to study the performance and combustion characteristics of a six-cylinder, four stroke, direct injection, heavy duty diesel engine as a base engine and when its power upgraded by 15% using a turbocharger. This code is open source, preprocessor is user-friendly and very easy in work and will used at any time. The computed results are compared with the results obtained by applying the engine simulation DIESEL-RK software. But the DIESEL-RK solver may be run under the control of an external code. In that case the interface of the program includes input & output text files. Templates of these files are generated automatically. The developed model provides reasonable estimates and the experimental validation of the model show that an appropriate agreement between mathematical model, DIESEL-RK software, and the real measurements, in addition the capability of the model to predict satisfactorily the performance, and combustion characteristics of the direct injection diesel engine. Simulation study was also performed to compare the turbocharged engine with the naturally aspirated direct injection diesel engine. This study examined the engines for operating parameters like brake power and brake specific fuel consumption over the entire speed range and revealed that turbocharging offers higher brake power and lower brake specific fuel consumption values for most of the operating range. The results indicated that turbocharging offers marginally higher brake thermal efficiency and enhancing the engine performance.

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