Combustion and Emission Characteristics of CNG Engine at Idle Conditons

2011 ◽  
Vol 130-134 ◽  
pp. 786-789
Author(s):  
Yi Tuan He ◽  
Na An
Keyword(s):  
Engine Speed ◽  
Maximum Power ◽  
Stepper Motor ◽  
Emission Characteristics ◽  
Excess Air ◽  
Throttle Valve ◽  
Cng Engine

The effects of ignition advance angle and excess air ratio on the combustion and emissions characteristics were investigated on a CNG engine at idle conditions. The throttle valve was fully closed. When the parameters were changed, the stepper motor was adjusted automatically to control the engine speed at 800r/min. When the θi is changed from 40 to 10o BTDC, the maximum ITE and the maximum power are observed at λ=1.1. As λ increases, the maximum ITE is corresponding to a greater θi. The COVimep will be increased if the θi is too advanced or too small. When λ is more than 1.3, the COVimep increases obviously. When λ=1.1, NOx emissions get the highest level.

Research on the Combustion and Emission Characteristics of Lean Burn CNG Engine

2011 ◽  
Vol 354-355 ◽  
pp. 508-512
Author(s):  
Lei Guan ◽  
Tian You Wang ◽  
Hai Yan Zhang ◽  
Zhi Jin Zhang
Keyword(s):  
Nox Emission ◽  
Emission Characteristics ◽  
Cylinder Pressure ◽  
Ignition Timing ◽  
Lean Burn ◽  
Excess Air ◽  
Combustion Duration ◽  
Flame Development ◽  
Development Duration ◽  
Cng Engine

The study on combustion characteristics of different excess air ratios (λ) and ignition timings was conducted on a lean-burn spark-ignition CNG engine, and the corresponding emission characteristics was also analyzed. The results show that the curve of cylinder pressure moves towards TDC, and the CoVimep decreases with the advance of ignition timing. With the excess air ratio increasing, the CoVimep increases while the cylinder pressure decreases firstly, and then increases. The flame development duration increases with the ignition timing advanced, but the rapid flame duration decreases, the total combustion duration basically keep constant, and all of them increase with the increasement of excess air ratio. Best fuel economy was gotten at λ=1.2. With the excess air ratio increasing, the CO and NMHC emissions decrease, the NOx emission firstly reaches to a peak value, which is about 3000ppm at λ=1.2, and then decreases. Both of the THC and CH4 emissions have opposite trends to NOx emission. All the emissions mentioned above increases with the advance of ignition timing.

Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

2019 ◽  
pp. 36-42
Author(s):  
A. P. Shaikin ◽  
I. R. Galiev
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Power Plants ◽  
Engine Speed ◽  
Combustion Engine ◽  
Fuel Mixture ◽  
Maximum Pressure ◽  
Chamber Volume ◽  
Excess Air ◽  
Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

Starting Control Strategy and Experimental Study of CNG Engine

2012 ◽  
Vol 562-564 ◽  
pp. 1044-1047
Author(s):  
Yi Tuan He ◽  
Fan Hua Ma ◽  
Zheng Liang Qi ◽  
Ren Zhe Chen
Keyword(s):  
Experimental Study ◽  
Control Strategy ◽  
Pulse Width ◽  
Engine Speed ◽  
Spark Timing ◽  
Cng Engine ◽  
Hc Emissions ◽  
Starting Control ◽  
Injection Pulse

To reduce the HC emissions of a CNG engine during starting period, starting experiments were carried out on a CNG engine. Injection pulse width (IPW) and spark advance angle () were controlled. The results indicate that wider injection pulse width and earlier spark timing cause higher HC emissions. To guarantee a reliable start and low HC emissions, the engine should start with relatively wider injection pulse width and earlier spark timing, and the injection pulse width and spark advance angle should be reduced gradually after the engine speed is steady.

Speed Control System Research on Hydraulic Torque Forklift

2014 ◽  
Vol 666 ◽  
pp. 188-193
Author(s):  
Ye Ni Li ◽  
Shui Xuan Chen ◽  
Hu Xiu Xu
Keyword(s):  
Control System ◽  
Engine Speed ◽  
Speed Control ◽  
Touch Screen ◽  
Stepper Motor ◽  
Labor Intensity ◽  
Control Parameters ◽  
System Research ◽  
Speed Control System ◽  
Screw Movement

By researching the characteristics of hydraulic torque forklifts, developed a device which achieved inching function. It can detect position of the handle, using Delta PLC controlled stepper motor driven screw movement, to achieve the control of the engine speed, and modify the control parameters via touch-screen on-site commissioning, to achieve a truck at idle operation, through the manipulation of the handle can Smooth and stable pan, lift or tilt operation, making operation more convenient forklift and reduces the operator's labor intensity, a high value market applications.

High-Pressure Microhydraulic Actuator

2003 ◽  
Author(s):  
Bruce P. Mosier ◽  
Robert W. Crocker ◽  
Judith L. Rognlien ◽  
Kamlesh D. Patel
Keyword(s):  
High Pressure ◽  
Power Conversion ◽  
Maximum Power ◽  
Stepper Motor ◽  
Gas Bubble ◽  
Polymer Monoliths ◽  
Electromechanical Actuators ◽  
Silica Monoliths ◽  
Conversion Efficiencies ◽  
Moving Parts

Actuation forces of 2.1 and 5.3 pounds (9.3 and 24 N) at velocities of 1 and 0.5 mm/s have been demonstrated with compact electrokinetic pumps producing 200 μL/min at 400 psi (2.8 MPa) and 100 μL/min at 1000 psi (6.9 MPa). This output compares favorably with electromechanical actuators (solenoid, piezoelectric, stepper motor) of similar size and is achieved silently and with no moving parts. Electrokinetic pump monoliths based on phase-separated porous methacrylate polymer monoliths and slurry-packed, sintered silica monoliths have been developed that can generate electrokinetic pressures of 3 psi/V (21 kPa/V) and 8 psi/V (6.9 kPa/V), respectively. Corresponding maximum power conversion efficiencies of 1% and 3% have been demonstrated in 10 mM TRIS-HCI at pH 8.5. Gas-bubble-free electrodes have been demonstrated to deliver 2 mA and seal to 1200 psi (8.3 MPa) for microhydraulic actuation.

NOx and N2O Emission Characteristics From Circulation Fluidized Bed Combustion of Blends of Paper Mill Sludge and Coal

2005 ◽  
Author(s):  
Xiao-Ping Chen ◽  
Li-Feng Gu ◽  
Chang-Sui Zhao ◽  
Ai-Qiang Zhu ◽  
Xin Sun
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Paper Mill ◽  
N2o Emission ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Emission Characteristics ◽  
Fluidized Bed Combustion ◽  
Paper Mill Sludge ◽  
Excess Air

With the rapid economic development and the increase in population in the whole world, the amount of municipal sewage (MS) is increasing and lead to a rapid increasing in amount of municipal sewage sludge (MSS). Combustion of municipal sewage sludge may be a viable solution for its disposal in some cases and so is its co-combustion with coal. Whereas significant information is available on NOx and N2O emissions characteristics of sludge and coal individually, not much has been reported on sludge/coal blends. In the present paper, investigations in NOx and N2O emission characteristics from circulation fluidized bed combustion of blends of municipal sewage sludge and coal were conducted in a 0.2MWth circulating fluidized bed test facility with cross section of 0.23×0.23m2 and height of 5.9m. Coal sample selected was a kind of lignite, while a kind of paper mill sludge was used as sludge sample. The influences of sludge/coal mixing rate, excess air ratio and second air ratio on NOx and N2O emission characteristics have been studied. Test results show that co-combustion of sewage sludge and coal is feasible. With the increasing in proportion of sludge of the sludge/coal blends, the temperatures in dense bed and freeboard decrease rapidly, and the emissions of NOx decrease while the emission of N2O increases obviously. With the increasing in excess air ratio, the emission concentrations of NOx and N2O increase. While with the increasing in secondary air ratio, the emission concentrations of NOx and N2O decrease.

Comparing the recovery performance of different thermoelectric generator modules in an exhaust system of a diesel engine both experimentally and theoretically

2019 ◽  
Vol 234 (1) ◽  
pp. 183-190
Author(s):  
Mehmet Akif Kunt ◽  
Haluk Gunes
Keyword(s):  
Diesel Engine ◽  
Thermoelectric Generator ◽  
Engine Speed ◽  
Waste Heat ◽  
Internal Resistance ◽  
Maximum Power ◽  
Thermoelectric Generators ◽  
Analysis Model ◽  
Maximum Absolute Error ◽  
Low Efficiency

In this study, a thermoelectric recovery system was designed to convert the exhaust waste heat of an internal combustion diesel engine directly to electric power and the performance was measured at different engine speeds in the unloaded state. The performances of two different thermoelectric generators were compared in a system designed using four modules. Maximum 0.92 W power was obtained for four modules at 3500 r/min, at an area of 0.0016 m2. Internal resistance of modules has increased according to the engine speed. The highest internal resistance obtained during the experiments is 11.69 Ω at engine speed of 3500 r/min. The characteristics of the overall thermoelectric generator performance is coherent with the analysis model. In the current graph according to engine speed, the maximum absolute error is calculated for modules TEG 12-8 and TEG1-199 as 0.010 and 0.044, respectively (at experimented 3500 r/min). To charge the battery under maximum power point conditions, 133 thermoelectric modules were required (TEG1-199). Maximum power transfer is obtained when the load resistor is connected in parallel at 10 Ω. It is seen that modular structure thermoelectric generators are more important alternative than Rankine cycle system in terms of waste heat recovery, despite thermoelectric system has low efficiency.

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