scholarly journals Cycle-to-Cycle Variation of a Diesel Engine Fueled with Fischer–Tropsch Fuel Synthesized from Coal

2019 ◽  
Vol 9 (10) ◽  
pp. 2032 ◽  
Author(s):  
Jinhong Shi ◽  
Tie Wang ◽  
Zhen Zhao ◽  
Zhifei Wu ◽  
Zhengwu Zhang

Cycle-to-cycle variations during the combustion phase should be comprehensively investigated because these variations are among the most serious causes of higher emissions and lower efficiency. The main objective of this study was to evaluate the relationship between cyclic variations and combustion parameters. The combustion and cyclic variation characteristics were investigated using a diesel engine operating on Fischer–Tropsch (F–T) fuel synthesized from coal. Experiments were conducted under full load conditions at three engine speeds of 1200, 2000, and 2800 rpm. The results revealed that cyclic variations of F–T diesel were lower than those of 0# diesel, acquired the minimum value at the speed of 2000 rpm, and reached the maximum at the speed of 2800 rpm. The mean fluctuation intensity of F–T diesel was 0.185, 0.189, and 0.205 at speeds of 1200, 2000, and 2800 rpm, respectively, smaller than that of 0# diesel under the corresponding conditions. The relationships between cyclic variations and combustion parameters were analyzed by correlation methods. Maximum in-cylinder pressure (Pmax) increased linearly with increased ignition delay, while it decreased linearly with increased combustion duration. The Pearson’s correlations between Pmax and ignition delay were 0.75, 0.78, and 0.73; however, the corresponding values between Pmax and combustion duration were 0.61, 067, and 0.65 when fueled with F–T diesel at speeds of 1200, 2000, and 2800 rpm, respectively. Moreover, the Pearson’s correlations of 0# diesel were higher than those of F–T diesel at the same operating loads. Compared with combustion duration, the ignition delay had more important effects on cyclic variations with a higher Pearson’s correlation. Furthermore, the ignition delay significantly influenced cyclic variation under a high speed load, while the combustion duration had a marked effect under low speed conditions. Overall, the results revealed the importance of combustion parameters on cyclic variation, which has great significance for controlled cyclic variation in diesel engines.

Author(s):  
Hayder A. Dhahad ◽  
Mohammed A. Abdulhadi ◽  
Ekhlas M. Alfayyadh ◽  
T. Megaritis

This study investigates the effect of combustion phase (premixed and diffusion phases) duration on the emissions emitted from a high speed direct injection (HSDI) diesel engine fueled with neat (100%) rapeseed methyl ester (RME) and run at a constant speed (1500 rpm) with single injection strategy at constant fuel injection pressure (800 bar) and varying fuel injection timings (−12,−9,−6,−3,0) ATDC, for two loads (2.5 and 5 bars) BMEP. The obtained results were compared with those obtained when the engine run at the same conditions but with ultra-low sulfur diesel fuel (ULSD). In-cylinder pressure was measured and analyzed using (LABVIWE) program. calculation program specially written in (MATLAB) software was used to extract the apparent heat release rate, the ignition delay, combustion duration and specify the amount of heat released during the premixed and diffusion combustion phases (premixed burn fraction PMBF) and (diffusion burn fraction DBF). Emission measurements included; NOx, CO, THC, CO2 and smoke number (SN). The results showed that at high load, RME generate higher NOx, CO and THC. Measurements and calculations indicated that ignition delay of RME was shorter than that of ULSD, which means less PMBF. This conflicting effect is probably due to the advanced start of combustion (SOC) leading to higher combustion temperature inside the combustion chamber and there will be less time available to complete the combustion. The emission results at low load showed that NOx and CO, generated by RME were less than those generated by USLD. USLD produced soot more than RME at high load and less at low load.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3931
Author(s):  
Faisal Lodi ◽  
Ali Zare ◽  
Priyanka Arora ◽  
Svetlana Stevanovic ◽  
Mohammad Jafari ◽  
...  

A comprehensive analysis of combustion behaviour during cold, intermediately cold, warm and hot start stages of a diesel engine are presented. Experiments were conducted at 1500 rpm and 2000 rpm, and the discretisation of engine warm up into stages was facilitated by designing a custom drive cycle. Advanced injection timing, observed during the cold start period, led to longer ignition delay, shorter combustion duration, higher peak pressure and a higher peak apparent heat release rate (AHRR). The peak pressure was ~30% and 20% and the AHRR was ~2 to 5% and ±1% higher at 1500 rpm and 2000 rpm, respectively, during cold start, compared to the intermediate cold start. A retarded injection strategy during the intermediate cold start phase led to shorter ignition delay, longer combustion duration, lower peak pressure and lower peak AHRR. At 2000 rpm, an exceptional combustion behaviour led to a ~27% reduction in the AHRR at 25% load. Longer ignition delays and shorter combustion durations at 25% load were observed during the intermediately cold, warm and hot start segments. The mass fraction burned (MFB) was calculated using a single zone combustion model to analyse combustion parameters such as crank angle (CA) at 50% MFB, AHRR@CA50 and CA duration for 10–90% MFB.


Author(s):  
Weilin Zeng ◽  
Xu He ◽  
Senjia Jin ◽  
Hai Liu ◽  
Xiangrong Li ◽  
...  

High-speed photography, two-color method, and thermodynamic analysis have been used to improve understanding of the influence of pilot injection timing on diesel combustion in an optical engine equipped with an electronically-controlled, common rail, high-pressure fuel injection system. The tests were performed at four different pilot injection timings (30 degree, 25 degree, 20 degree, and 15 degree CA BTDC) with the same main injection timing (5 degree CA BTDC), and under 100MPa injection pressure. The engine speed was selected at 1200 rev/min, and the whole injection mass was fixed as 27.4 mg/stroke. The experimental results showed that the pilot injection timing had a strong influence on ignition delay and combustion duration: advancing the pilot injection timing turned to prolong the ignition delay and shorten the combustion duration. The combustion images indicated that when pilot injection was advanced, the area of luminous flames decreased. The results of two-color method suggested pilot injection timing significantly impacted both the soot temperature distribution and soot concentration (KL factor) within the combustion chamber. 30 degree CA BTDC was the optimal pilot injection timing for in-cylinder soot reduction.


2020 ◽  
Vol 24 (1 Part A) ◽  
pp. 215-229
Author(s):  
Helin Xiao ◽  
Xiaolong Yang ◽  
Ru Wang ◽  
Shengjun Li ◽  
Jie Ruan ◽  
...  

In this study, the influences of injection timing and exhaust gas re-circulation on combustion and emissions characteristics of biodiesel/2-methylfuran blends are investigated on a modified water-cooled 4-cylinder four-stroke direct injection compression ignition engine. The experimental conditions are, respectively, to adjust injection timing and exhaust gas re-circulation ratio at 0.38 MPa break mean effective pressure with the engine speed at 1800 rpm constantly. With injection timing in advance, the peak cylinder pressure rose while maximum heat re-lease rate first decreased and next slightly raised. Ignition delay and brake specific fuel consumption reduced first and then raised while combustion duration and break thermal efficiency had the opposite trend. The NOx emissions in-creased, and HC emissions first reduced significantly and then slightly increased, while 1,3-butadiene and acetaldehyde emissions presented a reduction tendency. As exhaust gas re-circulation ratio increased gradually, ignition delay as well as combustion duration was prolonged. brake specific fuel consumption increased and break thermal efficiency declined. HC, CO, 1,3-butadiene, and acetaldehyde emissions raised while NOx emissions reduced significantly. Biodiesel could be-have well in a Diesel engine and thus a feasible alternative fuel for diesel. More-over, methylfuran addition into biodiesel could raise break thermal efficiency and the break thermal efficiency of BM20 is higher than BM10. However, both BM10 and BM20 appeared a combustion deterioration when injection timing at 2.5?CA before top head center.


2015 ◽  
Vol 773-774 ◽  
pp. 600-604 ◽  
Author(s):  
Mohd Herzwan Hamzah ◽  
Abdul Adam Abdullah ◽  
Agung Sudrajat ◽  
Nur Atiqah Ramlan ◽  
Nur Fauziah Jaharudin

The increase of industrial activities and motor vehicles globally causes rise demands in fossil fuel as energy sources. Since fossil fuel is non-renewable energy, many researches have been conducted to reduce the reliance to this fossil fuel. In conjunction, the number of waste plastic and tires around the world is increasing as a result of modern application and increasing number of motor vehicle. This type of waste is hard to decays and commonly dumped onto open landfills. Utilization of waste tires and plastics can produce alternative fuel that potentially can be used in diesel engine. In this paper, the combustion characteristics of two waste source fuels known as waste plastic disposal fuel (WPDF) and tire disposal fuel (TDF) are discussed. The combustion characteristics of both fuels are compared to diesel fuel. WPDF and TDF used in this experiment are pure concentrated and not blended with diesel fuel. The experiment is conducted using single cylinder YANMAR TF120M diesel engine. The engine is operated at constant load at 20 Nm and variable speed ranged from 1200 rpm to 2400 rpm. The combustion characteristics that discussed in this paper are ignition delay and peak pressure. Both characteristic are measured at two engine speed region which is low speed (1200 rpm) and high speed (2100 rpm). From the results obtained, it can be observed that WPDF has comparable ignition delay compared to diesel fuel while TDF has longest ignition delay compared to WPDF and diesel fuel. TDF also produce highest peak pressure compared to other tested fuels. Moreover, TDF is not suitable for high speed application since it cause backfire when engine speed reach 2200 rpm.


2014 ◽  
Vol 1008-1009 ◽  
pp. 951-955
Author(s):  
Deng Pan Zhang ◽  
Jia Yi Du ◽  
Yin Nan Yuan ◽  
Sheng Li Wei

A multi-point low-pressure methanol injection system was installed on manifold of a four cylinder turbocharged diesel engine, and the experiments on the engine operated with intake premixed methanol were conducted under wide operating conditions. The influence of the engine operating conditions on premixed methanol quantity was analyzed. The results show that, compared with straight diesel model, premixed methanol prolongs the ignition delay time of pilot diesel at the engine high load with low speed, and more methanol quantity can be premixed. At more than medium load with high speed, diesel ignition delay time with premixed methanol is shorter than with straight diesel model, and substitution ratio of methanol for diesel is significantly lower than that of low speed. Compared with the straight diesel mode at high speed, the fuel economy of the dual fueling mode is better, and NOx and soot emissions also are decreased, but CO and HC emissions are increased.


2021 ◽  
Vol 13 (11) ◽  
pp. 6482
Author(s):  
Sergejus Lebedevas ◽  
Laurencas Raslavičius

A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was ~10% and, in turn, resulted in close energy efficiency indicators (ηi) for both fuels and the possibility to enhance the NOx-smoke opacity trade-off. A comparative analysis by mathematical modeling of energy and traction characteristics for the universal multi-purpose diesel engine CAT 3512B HB-SC (1200 kW, 1800 min−1) confirmed the earlier assumption: at the regimes of external speed characteristics, the difference in Pme and ηi for MAO100 and D100 did not exceeded 0.7–2.0% and 2–4%, respectively. With the refinement and development of the interim concept, the model led to the prognostic evaluation of the suitability of MAO100 as fuel for the FPT Industrial Cursor 13 engine (353 kW, 6-cylinders, common-rail) family. For the selected value of the indicated efficiency ηi = 0.48–0.49, two different combinations of φz and m parameters (φz = 60–70 degCA, m = 0.5 and φz = 60 degCA, m = 1) may be practically realized to achieve the desirable level of maximum combustion pressure Pmax = 130–150 bar (at α~2.0). When switching from diesel to MAO100, it is expected that the ηi will drop by 2–3%, however, an existing reserve in Pmax that comprises 5–7% will open up room for further optimization of energy efficiency and emission indicators.


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