Investigation of Running HCCI With Dual-Fuel in a Small Scale Engine

Author(s):  
Yuh-Yih Wu ◽  
Hsien-Chi Tsai ◽  
Ta-Chuan Liu

Homogeneous charge compression ignition (HCCI) is a well-known technology that reduces the fuel consumption and exhaust emissions. This work implemented HCCI on a 150cc spark-ignition (SI) engine. The compression ratio of target engine was changed from 10.5 to 12.4 to enhance the compression temperature. In addition, a commercialized low-pressure injector was installed near the intake port for supplying fuel for HCCI operation. After the analysis of in-cylinder gas temperature, the dual fuel, with gasoline for the additive fuel and kerosene as the main fuel, was investigated in the small scale target engine. Experiments were executed through various excess air ratios, different gasoline additive ratios and then extension of engine load. Two-stage heat release, which provides energy to heat up the mixture during the compression stroke, was observed from HCCI combustion with kerosene fuel. The maximum rate of pressure rise (MRPR) could be reduced by increasing gasoline additive ratio of dual fuel without deteriorating the engine power output. By using the dual fuel method, the engine indicated mean effective pressure could be improved by a maximum percentage 23.9% and an average percentage 17.6% from just using kerosene fuel under the knocking limitation of MRPR equals to 4 bar/deg.

2021 ◽  
pp. 1-16
Author(s):  
Dipankar Kakati ◽  
Sumit Roy ◽  
Rahul Banerjee

Abstract The present investigation attempts to explore the prospects of the engine operational stability of a methanol induced partially premixed dual fuel operation under split injection strategy operating on a conventional single cylinder diesel engine coupled with a dedicated CRDI. The operation of such LTC regimes often deals with the stability concerns which are primarily characterized as the harshness of the operations and the non-repeatability of the combustion cycles. These two markers of operational stability have been mapped in this study through a comprehensive set of metrics of maximum pressure rise rate (ROPRmax) and Coefficient of Variation of Indicated Mean Effective Pressure (COVIMEP), Peak Pressure (COVPP) and Crank Angle of 50% mass fraction burn (COVCA50). The parametric investigation has been carried out at three different injection timings and pilot mass percentages at predefined methanol injection durations. The results have shown tremendous reductions in the non-repeatability of the combustion cycles and the harshness of the engine operation under split injection strategy, indicated by the lower scores of the stability indicators in comparison to the baseline single injection operation. Subsequently, the lowest scores of the maximum pressure rise rate and the Coefficient of Variation of indicated mean effective pressure, peak pressure and CA50 for the entire scope of investigation were registered as 0.62bar/CA, 0.75%, 0.48% and 1%, which were apparently observed as 65.5%, 86.36%, 94% and 53% lower than the corresponding scores registered in the baseline single injection operation.


2009 ◽  
Vol 137 (2) ◽  
pp. 26-36
Author(s):  
Zdzisław STELMASIAK

The paper presents comparison of a selected combustion parameters of dual fuel, spark ignited engine run on gasoline and methyl alcohol. To the testing was used a four cylinder Fiat 1100 MPI engine with multipoint injection of gasoline and alcohol to area of inlet valve. Preliminary tests of the engine pointed at significant differences of its performance when the engine was run on alcohol only and on gasoline only [1]. In connection with it an indicator tests were performed in order to determine, on their base, a differences present in runs of combustions of the both fuels. The paper presents comparison of maximal pressure, rate of pressure rise, average temperature of working medium, heat release rate, total angle of combustion and indicated efficiency. These parameters were analyzed both in function of crankshaft rotation angle as well as engine load. Obtained results show at different course of methanol combustion comparing to gasoline. Run of methanol combustion is more rapid, what leads to growth of engine efficiency and increase of maximal cylinder pressures. Growth of working medium temperatures during combustion, what can lead to growth of thermal load of the engine, can be included to disadvantageous phenomena. Performed tests point at necessity of engine tuning modification during feeding with methanol, what would enable to take full benefits of advantageous properties of that fuel. Simultaneously, optimization tests have enabled to restrict disadvantageous effects of combustion of methanol.


Author(s):  
Yuh-Yih Wu ◽  
Bo-Liang Chen

Homogeneous charge compression ignition (HCCI) is recognized as an advanced combustion system of internal combustion engine for reducing fuel consumption and exhaust emissions. This paper studied a 150 cc air-cooled four-stroke motorcycle engine operating HCCI combustion. The compression ratio was increased from 10.5 to 12.4 by modifying the cylinder head. The kerosene fuel was used without intake air heating and operated at various excess air ratios (λ), engine speeds, and EGR rates. The combustion characteristics and emissions on the target engine were measured. It was found that keeping the cylinder head temperature at around 120–130°C is important for stable experiment. Two-stage ignition was observed from the heat release rate curve, which was calculated from the cylinder pressure. Higher first stage ignition temperature causes higher peak cylinder gas temperature. Higher λ or EGR causes lower peak pressure, lower maximum rate of pressure rise (MRPR), and higher emission CO. However, EGR is better than excess air for decreasing the peak pressure and MRPR without deteriorating the engine output.


2014 ◽  
Vol 955-959 ◽  
pp. 3393-3399 ◽  
Author(s):  
Wei Zheng ◽  
Yan Ming Yang ◽  
Yun Long Li ◽  
Jian Qiu Zheng

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr,BOD5,SS,TN,NH3-N,TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002). The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.


2011 ◽  
Author(s):  
Morteza Fathi ◽  
Rahim Khoshbakhti Saray ◽  
Mohsen Pourfallah ◽  
Javad Kheyrollahi ◽  
Ghasem Javadirad

Author(s):  
Yuh-Yih Wu ◽  
Ching-Tzan Jang ◽  
Bo-Liang Chen

Homogeneous charge compression ignition (HCCI) is recognized as an advanced combustion system for internal combustion engines that reduces fuel consumption and exhaust emissions. This work studied a 150 cc air-cooled, four-stroke motorcycle engine employing HCCI combustion. The compression ratio was increased from 10.5 to 12.4 by modifying the cylinder head. Kerosene fuel was used without intake air heating and operated at various excess air ratios (λ), engine speeds, and exhaust gas recirculation (EGR) rates. Combustion characteristics and emissions on the target engine were measured. It was found that keeping the cylinder head temperature at around 120–130°C is important for conducting a stable experiment. Two-stage ignition was observed from the heat release rate curve, which was calculated from cylinder pressure. Higher λ or EGR causes lower peak pressure, lower maximum rate of pressure rise (MRPR), and higher emission of CO. However, EGR is better than λ for decreasing the peak pressure and MRPR without deteriorating the engine output. Advancing the timing of peak pressure causes high peak pressure, and hence increases MRPR. The timing of peak pressure around 10–15 degree of crank angle after top dead center indicates a good appearance for low MRPR.


Author(s):  
Mohamed Y. E. Selim ◽  
M. S. Radwan ◽  
H. E. Saleh

The use of Jojoba Methyl Ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or LPG at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or liquefied petroleum gas (LPG) as the main fuel and Jojoba Methyl Ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic data of 100 engine cycle in terms of maximum pressure and its pressure rise rate. The tests examined the following engine parameters: gaseous fuel type, engine speed and load, pilot fuel injection timing, pilot fuel mass and compression ratio. Results showed that using the Jojoba fuel with its improved properties has improved the dual fuel engine performance, reduced the combustion noise, extended knocking limits and reduced the cyclic variability of the combustion.


2021 ◽  
Author(s):  
S. J. van der Spuy ◽  
D. N. J. Els ◽  
L. Tieghi ◽  
G. Delibra ◽  
A. Corsini ◽  
...  

Abstract The MinWaterCSP project was defined with the aim of reducing the cooling system water consumption and auxiliary power consumption of concentrating solar power (CSP) plants. A full-scale, 24 ft (7.315 m) diameter model of the M-fan was subsequently installed in the Min WaterCSP cooling system test facility, located at Stellenbosch University. The test facility was equipped with an in-line torque arm and speed transducer to measure the power transferred to the fan rotor, as well as a set of rotating vane anemometers upstream of the fan rotor to measure the air volume flow rate passing through the fan. The measured results were compared to those obtained on the 1.542 m diameter ISO 5801 test facility using the fan scaling laws. The comparison showed that the fan power values correlated within +/− 7% to those of the small-scale fan, but at a 1° higher blade setting angle for the full-scale fan. To correlate the expected fan static pressure rise, a CFD analysis of the 24 ft (7.315 m) diameter fan installation was performed. The predicted fan static pressure rise values from the CFD analysis were compared to those measured on the 1.542 m ISO test facility, for the same fan. The simulation made use of an actuator disc model to represent the effect of the fan. The results showed that the predicted results for fan static pressure rise of the installed 24 ft (7.315 m) diameter fan correlated closely (smaller than 1% difference) to those of the 1.542 m diameter fan at its design flowrate but, once again, at approximately 1° higher blade setting angle.


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