Effect of Hydrogen Addition on Laminar Burning Velocity of Liquefied Petroleum Gas Blends

Abstract

The consequences of H2 enrichment on the laminar burning velocity (LBV) of various liquefied petroleum gas (LPG) blends have been studied experimentally and numerically. The study was carried out at various equivalence ratios (ϕ) (from 0.8 to 1.3 in steps of 0.1). Experiments were conducted on various LPG blends, by adding hydrogen up to 60% by volume in steps of 20, using the heat flux method (HFM) experimental setup. A detailed computational study was conducted using a PREMIX code to predict the LBV and to explain the flame structure of LPG–hydrogen–air mixtures. LBV predictions using two different chemical kinetic mechanisms such as Aramco Mech 2.0 and USC Mech II mechanism were compared with experimental results of the LBV for all the fuel mixture compositions studied. The LBV predicted by the Aramco Mech 2.0 mechanism matched well with the present experimental results. The LBV of the LPG–air mixture was observed to be increasing upon hydrogen addition. A linear increase in the LBV upon hydrogen addition was observed until 40% H2 addition in the fuel mixture. The effect of hydrogen addition was found to be more significant at 60% H2, showing a nonlinear increase in the LBV from 40 to 60% H2 addition. The effect of hydrogen addition on the LBV was observed to be prominent in the rich mixture side. The variation in the LBV with hydrogen enrichment was found to be dependent on the concentration of C3H8 in the fuel mixture. The effect of the composition of propane and butane on the LBV of LPG was also studied. The laminar burning velocity at elevated temperatures was measured using a diverging channel setup for LPG (60% C4H10–40% C3H8) at various H2 compositions. The temperature exponent was found to be decreasing with the hydrogen addition. The minimum value of the temperature exponent for all the studied mixture compositions was observed at ϕ = 1.1.

Minireview on the Leakage Ignition and Flame Propagation Characteristics of Hydrogen: Advances and Perspectives

“…Experimental verification is required on various aspects of hydrogen gas mixtures, such as under what conditions are such mixtures the most harmful. Research on syngas can prevent the unknown hazards caused by syngas and enable energy development. , Most existing research on hydrogen gas mixtures has focused on extremely idealized conditions, with uniformly mixed gas being used for testing. However, the densities of various gases are different; thus, the gas distribution in space is often uneven, and the gas distribution under different standing times is different.…”

The State of the Art of Laminar Burning Velocities of H2-Enriched n-C4H10–Air Mixtures

“…Therefore, new solutions to avoid these accidents are needed. In this sense, experimental and numerical investigations have been conducted on n-butane-air flames to determine their global combustion parameters, including ignition delay times [6][7][8], propagation parameters (peak explosion pressures, explosion times, maximum rates of pressure increase, and deflagration indexes) [9][10][11], as well as the laminar burning velocities [8,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…However, the combustion performances of n-butane could be improved by adding hydrogen. Over the years, hydrogen addition to gaseous fuel-air mixtures has been used to enhance combustion of some fuels frequently used in the industry, car engines, or households such as natural gas [32,34,42], methane [29], biogas [43,44], and LPG [28,35,45]. Moreover, the combustion characteristics of ammonia with hydrogen addition have been the subject of recent studies.…”

“…Adiabatic flame temperatures, a main feature involved in the combustion process that indicates the maximum temperature at equilibrium that a fuel mixture can achieve, were calculated by some researchers using different computing packages [28,[50][51][52][53]. These studies revealed that the adiabatic flame temperatures of n-C 4 H 10 -H 2 -air mixtures increase first with increases in the equivalence ratio (ϕ), reaching a maximum value at about ϕ = 1.1, and then decrease at higher values of the equivalence ratio.…”

Effects of Initial Temperature on the Deflagration Characteristics and Flame Propagation Behaviors of CH4 and Its Blends with C2H6, C2H4, CO, and H2

“…Researchers studied a great deal about flame propagation, and most of this research was conducted for methane, − ethane, propane, hydrogen, and methanol . There are many studies conducted to investigate the burning velocities of binary fuel mixtures, such as CH 4 –CO 2 , , H 2 –CH 4 , , CH 4 –C 2 H 4 , CH 4 –C 2 H 6 , iso-octane-methane, , natural gas–H 2 , LPG–H 2, biogas–H 2 , and H 2 –CO, , due to the new interest in the utilization of substitute fuels.…”