Hydrogen-Enriched Natural Gas Swirling Flame Characteristics: A Numerical Analysis

Abstract

Increasing the amount of hydrogen (H2) in natural gas mixtures contributes to gas turbine (GT) decarbonisation initiatives. Hence, the swirling flame characteristics of natural gas mixtures with H2 are investigated in the current work using a numerical assessment of a single swirl burner, which is extensively employed in GT combustors. The baseline numerical and experimental cases pertained to natural gas compositions largely consisting of methane (CH4). The results show that the numerical model adequately describes the swirling component of the flame observed in the experiment. Altogether, the findings show that hydroxyl (OH) radical levels increase in H2-enriched CH4 flames, implying that greater OH pools are responsible for the change in flame structure caused by considerable H2 addition. The addition of 10 % H2 is predicted to raise the peak flame temperature by 4 % compared to the baseline CH4 flame. Therefore, adding 10 % H2 into a GT combustor without any flowrate tuning raises the risk of turbine material deterioration and increased thermal NOx emission. Due to the lower volumetric Lower Heating Value (LHV) of H2, which needs a higher volumetric fuel flow rate than burning natural gas/CH4 at the same thermal output, the addition of 2 % H2 is predicted to reduce the peak flame temperature by 4 % compared to the baseline CH4 flame. Hence, if 2 % H2 is fed into a GT combustor without any flowrate tuning, the required load may not be obtained. When compared to the baseline CH4 case, the addition of 5 % H2 is predicted to provide almost identical peak flame temperature, which can be postulated that the addition of 5 % H2 can produce roughly the same peak flame temperature as the pure CH4 flame because the Wobbe Index is comparable. Therefore, it reveals that incorporating 5 % H2 in the natural gas-fired GT combustor with nearly no modification is viable. More research, however, is required to fully capture the flame structure and strain for assessing transient-related phenomena such as flashback and blow off by raising the H2 proportion and utilising a higher precision turbulence model.

Large Eddy Simulation of Hydrogen/Natural Gas/Air Premixed Swirling Flames and CIVB Flashback Risks

“…The simulated combustion process of NG firing and NG-H 2 co-firing is based on the actual experimental setup from our previous study [14]. The computational domain of the burner, as well as the related boundary condition locations, are shown in Figure 1.…”

“…For convective terms estimation and other spatial derivatives, the linear-upwind interpolation scheme (the second-order upwind scheme) and linear interpolation (second-order central differences) were used, respectively. Previous studies have shown that the probability density function (PDF) and flamelet formulations are adequate for describing the complex turbulence-chemistry interaction within the combustor [13,[14][15]24]. As a result, the current study employed the non-adiabatic steady flamelet model with a detailed chemistry mechanism (GRI Mech 3.0), which computes temperature and species composition through the use of a variable known as the mixture fraction, which reflects the local fuel/oxidizer ratio [25].…”

“…Therefore, there are still a few key issues that are preventing the GT combustion systems from improving [11]. As a result, the desire to create GTs that can run on a variety of fuels, from natural gas (NG) to NG blended with H 2 , frequently runs into operability problems in the form of the aforementioned instabilities [12][13][14][15].…”

Green hydrogen prospects in Peninsular Malaysia: a techno-economic analysis via Monte Carlo simulations

“…Since the energy industry has been the primary source of GHG emissions in Peninsular Malaysia [66], the use of powerto-gas-to-power technology is one possible method for decarbonizing Peninsular Malaysia's energy systems and allowing long-term economic change [1,67]. This strategy emphasizes the significance of both key aspects of the hydrogen sector, such as green hydrogen production [1,68] and green hydrogen for power generation (hydrogen cofiring) [1,[69][70]]. Malaysia's diverse range of solar resources, combined with their significant capacity, highlight the country's enormous potential for solar PV power generation.…”

Oil Palm Wastes Co-firing in an Opposed Firing 500 MW Utility Boiler: A Numerical Analysis

“…Hence, numerous strategies are being developed to decrease CO2 emissions from the above said power plants, such as ultra-supercritical technology [10], integrated gasification combined cycle (IGCC) [10], double reheat technology [10], carbon capture and storage (CCS) [10], oxy-fuel combustion [7], carbon capture and storage [7], and the use of low-carbon/carbon-neutral fuels [10][11]. When it comes to the use of low-carbon/carbon-neutral fuels, hydrogen is anticipated to play a significant part in the future formation of a low-carbon society [9,[11][12][13]15]. Nevertheless, due to its high volatility [11], hydrogen storage and transportation remain complicated [13,16].…”