Gasoline compression combustion engine has the advantages of low emission and high efficiency, which is very promising for research, but it is difficult to apply under low-load conditions. Gasoline has the characteristics of low reactivity; in the case of low thermodynamic state in the cylinder, the fire delay period of the fuel is longer, and the combustion phase is relatively lagging, which will lead to the increase of combustion cycle fluctuations, and even difficult to ignite and other adverse combustion phenomena. In order to improve the combustion stability of Gasoline Compression Ignition (GCI) engine under low-load condition and expand the limit of low-load combustion boundary, gasoline was reformed without catalyst under the boundary condition of reforming temperature of 488 K and reforming equivalent ratio of 8, and the concentration of reformed product was measured by a gas detection device. Subsequently, the coupling of the reformed product and spark plug with GCI engine under low-load condition was investigated to analyze the effect on engine combustion and emission. The results showed that the initial combustion timing of the low-load GCI engine was late, but the addition of reformed products could advance the combustion phase, shorten the combustion duration, reduce single-cycle NOx emission, and improve the small-load operation characteristics of GCI engine. Coupled spark plug ignition on the basis of adding reformed products could further improve the problem of combustion stability under low-load GCI engine. And the optimization effect became more obvious as the ignition position of the spark plug moves down. However, spark plug ignition would cause local high temperature areas, resulting in an increase in NOx emission.
[1] Sathiyaseelan V., Lakshmana G.S., Sathyamurthy R., Comparative assessment of low-concentration ethanol and waste fish oil biodiesel blends on emission reduction and performance improvement in variable compression ratio engine. Journal of Thermal Science, 2023, 32(3): 1306–1319.
[2] Roberts J., Chuahy F., Kokjohn S., et al., Isolation of the parametric effects of pre-blended fuel on low-load gasoline compression ignition (GCI). Fuel, 2019, 237: 522–535.
[3] Kavuri C., Paz J., Kokjohn S., A comparison of reactivity-controlled compression ignition (RCCI) and gasoline compression ignition (GCI) strategies at high load, low speed conditions. Energy Conversion & Management, 2016, 127: 324–341.
[4] Kavuri C., Paz J., Staaden D., et al., Post-injection strategies for gasoline compression ignition combustion under high load conditions: Understanding the role of premixed, main, and post-injections in soot mitigation and load extension. Fuel, 2018, 233: 834–850.
[5] Dimitrakopoulos N., Tunér M., Evaluation of engine efficiency, emissions and load range of a PPC concept engine, with higher octane and alkylate gasoline. Fuel, 2020, 275: 117995.
[6] Dimitrakopoulos N., Belgiorno G., Tunér M., et al., Effect of EGR routing on efficiency and emissions of a PPC engine. Applied Thermal Engineering, 2019, 152: 742–750.
[7] Yang T., Yin L., Long W., et al., Modeling and control of gasoline PPC engine approaching high efficiency with constraints. IFAC-PapersOnLine, 2018, 51: 442–447.
[8] Wang B.Y., Study on compression combustion load expansion and ignition characteristics of Low octane fuel. Beijing, Tsinghua University, China, 2016.
[9] Hao H., Liu F., Liu Z., et al., Compression ignition of low-octane gasoline: Life cycle energy consumption and greenhouse gas emissions. Applied Energy, 2016, 181: 391–398.
[10] Liu H., Mao B., Liu J., et al., Pilot injection strategy management of gasoline compression ignition (GCI) combustion in a multi-cylinder diesel engine. Fuel, 2018, 221: 116–127.
[11] Pan J., Li X., Yin Z., et al., Effects of intake conditions and octane sensitivity on GCI combustion at early injection timings. Fuel, 2021, 298: 120803.
[12] Yang B., Liu L., Jia S., et al., Experimental study on particle size distribution of gasoline compression ignition (GCI) at low-load condition. Fuel, 2021, 294: 120502
[13] Wang C., Yue Z., Zhao Y., et al., Numerical simulation of the high-boosting influence on mixing, combustion and emissions of high-power-density engine. Journal of Thermal Science, 2023, 32: 933–946.
[14] Ye Y., Liu H., Li J., et al., A Numerical investigation on the effects of intake swirl and mixture stratification on combustion characteristics in a natural-gas/diesel dual-fuel marine engine. Journal of Thermal Science. 2023, 32: 414–426.
[15] Xiao G., Zhang Y., Lang J., et al., Experimental study on the effect of intake temperature on the combustion and emission performance of gasoline direct injection compression ignition engines. Journal of Internal Combustion Engines, 2014, 32(2): 125–130.
[16] Solaka H., Aronsson U., Tuner M., et al., Investigation of partially premixed combustion characteristics in low-load range with regards to fuel octane number in a light-duty diesel engine. SAE Technical Paper 2012-01-0684, 2012.
[17] Borgqvist P., Tunestal P., Johansson B., Gasoline partially premixed combustion in a light duty engine at low-load and idle operating conditions. SAE Technical Paper 2012-01-0687, 2012.
[18] Borgqvist P., Tuner M., Tunestal P., et al., The usefulness of negative valve overlap for gasoline partially premixed combustion, PPC. SAE Technical Paper 2012-01-1578, 2012.
[19] Sellnau M., Sinnamon J., Hoyer K., et al., Gasoline direct injection compression ignition (GDCI) - diesel-like efficiency with low CO2 emissions. SAE Technical Paper 2011-01-1386, 2011.
[20] Jian L., Qianzhen G., Zhe R., Tian L., Genxiang G., Dong H., Thermochemical recuperation for stirling engines by diesel steam reforming: thermodynamic analysis. Journal of Thermal Science, 2022, 31(6): 2111–212.
[21] Wang Y., Wang H., Yao M., The effect of PRF90 low-temperature reforming products on engine combustion and emissions. Journal of Internal Combustion Engines, 2019, 6: 489–495
[22] Liu L., Cao Q., Wang Y., Feasibility investigation of Low-temperature reforming technology on a GCI engine. Fuel, 2023, 343: 127959.
[23] Liu L., Cao Q., Wang Y., Theoretical investigation the effect of Low-temperature reformed products of gasoline on engine combustion and emission at variable loads. Fuel, 2022, 322: 124154.
[24] Wang H., Yao M., Reitz R.D., Development of a reduced primary reference fuel mechanism for internal combustion engine combustion simulations. Energy & Fuels, 2013, 27(12): 7843–7853.
[25] Bharath A.N., Reitz R.D., Rutland C.J., Impact of active control turbocharging on the fuel economy and emissions of a light-duty reactivity controlled compression ignition engine: a simulation study. Frontiers in Mechanical Engineering, 2021, 7: 610891.
[26] Mohamad T.I., Mansor M.R.A., Mahmood W.M.F.W., Numerical study of the effect of injection strategy and compression ratio on gasoline/diesel fueled RCCI engine. SAE Technical Papers, 2018-32-0017, 2018.
[27] Yang B., An experimental investigation on the effects of injection strategy on combustion and emission characteristics of gasoline compression ignition (GCI). Tianjin University, China, 2017.
