Study of Operation of a Pilot CFB-Reactor in Dynamic Conditions

2003 ◽  
Author(s):  
Antti S. Tourunen ◽  
Jaakko J. Saastamoinen ◽  
Jouni P. Ha¨ma¨la¨inen ◽  
Kari M. Paakkinen ◽  
Timo E. Hyppa¨nen ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Response Analysis ◽  
Process Conditions ◽  
Stable Operation ◽  
Fuel Quality ◽  
Feed System ◽  
Dynamic Conditions ◽  
Fuel Feed

The development of a high efficiency CFB power plant (once-through supercritical CFB technology) and the use of alternative fuels require advanced methods of control and knowledge of the dynamic behavior of the furnace. Dynamic response analysis is needed for design of control algorithms in load changes. The operation of a pilot CFB-reactor in dynamic conditions and in load changes is analyzed experimentally and by modeling at different process conditions. Reactivity parameters for different fuels can be extracted from simple dynamic measurements and then used in computations studying operation in load changes. Dynamic studies are also required to see the necessary requirements for the fuel quality and fuel feed system to maintain stable operation. For high volatile coals the fuel feeding must be steadier to keep the variation in the outlet oxygen concentration at some range than with coals with low reactivity or alternatively greater air coefficient is needed to prevent too low O2 concentrations, which can cause an increase in CO emissions. The fuel quality can be characterized by the fluctuation of oxygen concentration in flue gases in steady operation conditions, which depends on the fluctuations in the combustion and in the fuel feed and on operational conditions. The amplitude of the fluctuations was studied. For advanced controls, it is necessary to know the factors affecting the process dynamics, such as reactivity and the behavior of char inventory in bed. This information is also necessary in developing and optimizing the CFB boiler considering emissions, combustion process and furnace scale up.

scholarly journals Comparison of Diesel Engine Vibroacoustic Properties Powered by Bio and Standard Fuel

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1478
Author(s):  
Radoslaw Wrobel ◽  
Gustaw Sierzputowski ◽  
Zbigniew Sroka ◽  
Radostin Dimitrov
Keyword(s):  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Significant Other ◽  
Engine Torque ◽  
Engine Model ◽  
Vehicle Operation ◽  
History Of ◽  
Profile Changes ◽  
The Time Domain

Alternative fuels appeared soon after the first internal combustion engines were designed. The history of alternative fuels is basically as long as the history of the automotive industry. Initially, fuels whose physicochemical properties allowed for a change in parameters of the combustion process in order to achieve greater efficiency and reliability were searched for. Nowadays, there are significantly more variables; in addition to the above mentioned parameters, alternative fuels are being sought that will ensure environmental protection during vehicle operation and improve the ergonomics of use. This article outlines the results of the authors’ own comparative tests of vibrations of a vibroacoustic character. Based on a popular engine model, the vibration–acoustic responses of a system powered by two types of fuel, namely, diesel and biodiesel (B10), are compared. The research consists of comparing vibrations in both time and frequency domains. In the case of the time domain, the evaluation was performed with vibrations as a function of engine torque and speed. In the case of frequency analysis, the focus was on changes in the frequency response for the tested fuels. The research shows that the profile of vibroacoustic vibrations changes in the case of biodiesel power supply in relation to standard fuel. The vibration profile changes significantly as a function of speed and only slightly in relation to the engine load. The results presented in this article show different vibroacoustic responses of an engine powered by diesel and biodiesel; the change is minor for lower speeds but significant (other harmonics are dominant) for higher speeds (changes in the dominant harmonic magnitude of up to 10% at a crankshaft speed of 3000 rpm).

Effects of Natural Gas Compositions on Engine In-Cylinder Process

2015 ◽  
Vol 1092-1093 ◽  
pp. 498-503
Author(s):  
La Xiang ◽  
Yu Ding
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Engine Performance ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Test Bed ◽  
Promising Alternative ◽  
Natural Gas Engines ◽  
Lower Maximum

Natural gas (NG) is one of the most promising alternative fuels of diesel and petrol because of its economics and environmental protection. Generally the NG engine share the similar structure profile with diesel or petrol engine but the combustion characteristics of NG is varied from the fuels, so the investigation of NG engine combustion process receive more attentions from the researchers. In this paper, a zero-dimensional model on the basis of Vibe function is built in the MATLAB/SIMULINK environment. The model provides the prediction of combustion process in natural gas engines, which has been verified by the experimental data in the NG test bed. Furthermore, the influence of NG composition on engine performance is investigated, in which the in-cylinder maximum pressure and temperature and mean indicated pressure are compared using different type NG. It is shown in the results that NG with higher composition of methane results in lower maximum temperature and mean indicated pressure as well as higher maximum pressure.

Thermal Analysis of Plastic Contained Decorative Materials under Different Oxygen Concentration

2012 ◽  
Vol 550-553 ◽  
pp. 2786-2790
Author(s):  
Zhen Zhao ◽  
Feng Liu ◽  
Qiang Zhang ◽  
Lei Wang
Keyword(s):  
Thermal Analysis ◽  
Weight Loss ◽  
Oxygen Concentration ◽  
Integral Method ◽  
Combustion Process ◽  
Order Reaction ◽  
Maximum Weight ◽  
Ignition Point ◽  
First Order ◽  
Maximum Weight Loss

The combustion characteristics of decorative materials were studied by thermal analysis. The experiments were performed in three kind of oxygen concentration (7%, 14%, 21%), the heating rate were 15°C/min and 30°C/min respectively. The ignition point and maximum weight loss rated were analyzed. Based on the Coats-Redfern integral method, the results show that the combustion process were first order reaction.

Ethers and esters as alternative fuels for internal combustion engine: A review

2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua
Keyword(s):  
Alternative Fuels ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Future Research ◽  
Particulate Emissions ◽  
Ic Engine

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.

scholarly journals Implementation of packed column for biogas purification as fuel for motorcycle injection systems for performance improvement

2021 ◽  
Vol 4 (1(112)) ◽  
pp. 86-93
Author(s):  
Syamsuri Syamsuri ◽  
Yustia Wulandari Mirzayanti ◽  
Zain Lillahulhaq ◽  
Achmad Bagus Hidayat
Keyword(s):  
Alternative Fuels ◽  
Packed Column ◽  
Combustion Process ◽  
Primary Energy ◽  
Average Error ◽  
Spark Ignition Engines ◽  
Chassis Dynamometer ◽  
Higher Power ◽  
Biogas Purification ◽  
Liquid Flows

The use of gasoline for primary energy consumption can reduce crude oil, contained in the earth. The development of alternative fuels such as biogas and biofuel is very critical to overcoming this problem. Biogas requires purification to remove some contaminant particles that interfere with the combustion process. The packed column is generally applied to absorb and separate gas and liquid mixture. It is more efficient due to the liquid flows down the column of steam naturally without the supply of energy from outside the system. This study focuses on determining the effect of the packed column biogas purification process. Biogas is applied as an alternative fuel in spark-ignition engines (SIE). The test is carried out using a chassis dynamometer to obtain power and torque data. The use of the packed column for biogas fuel purification can produce higher performance compared to unrefined biogas. The unrefined biogas still contains impurities that can interfere with the combustion process. This condition is proven by measuring the power and torque of the vehicle on the chassis dynamometer, where the filtered biogas produces higher power and torque. Tests were carried out both using the packed column and without the packed column. Variations from speed to torque, to power, to SFC and BMEP are considered. In this study, validation is in good agreement with previous studies. Overall, the results show that the average error between using the packed column and without the packed column for torque, power, SFC and BMEP is increased by approximately 7 %. Purification of biogas using the packed column using Ca(OH)2 can bind CO2 and obtain pure methane gas with a higher heating value. In conclusion, the packed column for biogas purification as fuel for motorcycle injection systems can be applied

scholarly journals Some aspects of cycle variability at the Diesel engine fuelled with animal fats

2019 ◽  
Vol 112 ◽  
pp. 01014
Author(s):  
Adrian Nicolici ◽  
Constantin Pană ◽  
Niculae Negurescu ◽  
Alexandru Cernat ◽  
Cristian Nuţu
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Experimental Investigations ◽  
Maximum Pressure ◽  
Content Increase ◽  
Animal Fats ◽  
Viable Solution

The progressive diminution of the oil reserves all over the world highlights the necessity of using alternative fuels derived from durable renewable resource. The use of the alternative fuels represents a viable solution to reduce the pollutant emissions and to replace fossil fuels. Thus, a viable solution is the use of the animal fats in mixture with the diesel fuel at the diesel engines. A D2156 MTN8 diesel engine was firstly fuelled with diesel fuel and then with different blends of diesel fuel-animal fats (5% and 10% animal fats content). In the paper are presented some results of the experimental investigations of engine fuelled with preheated animal fats. The raw animal fats effects on the combustion process and on the pollutant emissions at different engine loads and 1450 rev/min engine speed are showed. The engine cycle variability increases at the animal fats content increase. The cycle variability for maximum pressure, maximum pressure angle and indicated mean effective pressure is analysed. The cycle variability coefficients values don’t exceed the recommended values of the standard diesel engine.

scholarly journals Production of biodiesel from Annona muricata seeds

2019 ◽  
Vol 90 ◽  
pp. 01011 ◽  
Author(s):  
Wai-Leong Wong ◽  
Waye-Hong Lim ◽  
Jet Si ◽  
Man-Kee Lam ◽  
Yeek-Chia Ho
Keyword(s):  
Factorial Design ◽  
Potassium Hydroxide ◽  
Alternative Fuels ◽  
Calorific Value ◽  
Environmental Issues ◽  
Raw Material ◽  
Biodiesel Production ◽  
Fuel Quality ◽  
Annona Muricata ◽  
Temperature Time

Biodiesel is one of the effective alternative fuels to overcome the problems associated with environmental issues and energy crisis. However, the production of biodiesel from edible oil has provoked the food versus fuel dispute. Thus, a non-edible crop, Annona muricata, is selected as the raw material to produce oil for biodiesel production. In this study, A. muricata oil was extracted with n-hexane at 70 °C for 6 h. Subsequently, the oil was transesterified with methanol and potassium hydroxide (KOH) to produce biodiesel. The significance of transesterification parameters including temperature, time, catalyst concentration, and oil-to-methanol ratio on biodiesel yield (%) was established through two-level factorial design. The factorial design shows that all parameters are significant. Besides, the high content of monounsaturated fatty acid (oleic acid) in the resultant biodiesel suggests that A. muricata biodiesel could display good fuel quality. This hypothesis is proven by the excellent calorific value (39.21 MJ kg-1).

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