Effects of the substitution rate of natural gas on the combustion and emission characteristics in a dual-fuel engine under full load

Abstract

Diesel-piloted natural gas has been considered one of the most promising methods of using natural gas in a compression-ignition engine with few modifications, as this approach benefits from a high thermal efficiency resulting from a high compression ratio. This study experimentally investigated the impact of the natural gas substitution rate on the characteristics of combustion and emissions. Tests were performed under full-load operating conditions at a fixed speed of 1200 r/min with optimized injection timing, and the substitution rate of natural gas was varied with the fixed total fuel energy for different analyses. The in-cylinder pressure, pressure rise rate, heat release rate, cyclic variation of the maximum cylinder pressure (P max ) and emissions of HC, CO, NO x , and smoke were analyzed. The results indicate that P max and the maximum pressure rise rate initially increase and then decrease as the substitution rate of natural gas increases, whereas the heat release rate and standard deviation of P max increase. Moreover, HC and CO increase as the substitution rate of natural gas increases, whereas NO x and smoke emissions exhibit a trade-off trend.

Prediction and optimization of dual-fuel marine engine emissions and performance using combined ANN with PSO algorithms

“…The iteration process continues until the maximum number of iterations or reached the termination condition. Update the new position and velocity of each particle based on equations ( 14) and (15).…”

“…Obtained the fitness value of generated particles by using equation ( 16); Step4. Updated particle position and velocity according to equations ( 14) and (15).…”

“…[11][12][13] Arat et al 14 studied the effects of hydrogen-doped compressed natural gas on engine propulsion performance, fuel consumption, and emissions at 25% and 50% diesel substitution rates. Lyu et al 15 used experiments to study under the best injection timing conditions and found that as the substitution rate increases, Hydrocarbon (HC) and carbon monoxide (CO) emissions will increase. Many researchers have conducted in-depth studies on the influence of rail pressure and excess air coefficient on the dual-fuel engine.…”

N-doped Mo2C particles as a cathode catalyst of asymmetric neutral-alkaline microbial electrolysis cells for hydrogen production

“…One of the world's most severe challenges in the 21st century is the increasing energy demand of mankind. 1 So far, more than 1.3 billion people in the world still have no access to electricity. 2 Global energy consumption is estimated to increase by about 48% from 2012 to 2040.…”

Advances in Diesel-LNG Internal Combustion Engines

“…A diesel ICE can be easily converted to an LNG-diesel 2F ICE, which makes the technology suitable for both new ICE manufacturing and retrofitting existing diesel ICEs. Some known issues of the 2F diesel-LNG ICEs developed so far are the limited replacement ratio, efficiency deterioration, and the incomplete combustion of the LNG at low load conditions [34,35]. These issues may be addressed by assisted turbocharging, where the speed of the turbocharger can be altered from the balanced operation of turbine and compressor, by fitting an electric motor-generator to the turbocharger shaft (the FIA F1 style MGU-H, [26,36]) or connecting the turbocharger shaft to the crankshaft via gear and a variable speed transmission, that is an evolution of the Torotrak V-Charge supercharger, [37][38][39], for super turbocharging, [26,27,40], and obviously with a better injection system.…”