Hi Xiongbo,

we've been using the GRI 3.0 reaction mechanism to simulate the combustion of natural gas / hydrogen blends in industrial furnaces, usually without any problem.

Yes, I am also thinking about using the GRI 3.0 to simulate the combustion of the natural gas/hydrogen blends. However, Sameera, who is a Principal Engineer for Converge CFD, recommended us to use the detailed H2 mechanism with 57 species and 268 reactions seems to have CH4 chemistry as well. Moreover, we need to check if this mechanism can give similar LFS for CH4 as GRI-3.0. If this is the case, then we can use this for CH4/H2 combustion.

Consequently, without measured data to validate the CH4/H2 combustion, I am not sure that this mechanism is working correctly for my current application. I will run these case to investigate the sensitivity of these two mechanism.

If there yields some interesting results, I share you as soon as possible.

The mechanism can be download by the following link:

https://www.cerfacs.fr/cantera/mechanisms/hydro.php

Thanks for your suggestions

Regards,

Xiongbo

Jubin V Jose Jörg Leicher

What is the purpose of this simulation? Are you trying to optimize fuel quality, tweak engine conditions to improve performance or perhaps understand and improve the mechanism.

Techanically, we conducted some experiments on a spark ignition engine fueled with na gas and hydrogen! Consequentl, we want to investigate effects of different combustion chamers on the combustion and emissions!

Duan Xiongbo Thank you for the explanation. I think it would be wise for you to think about the purpose of your research and design your experiments appropriately.

It appears to me the goal of your current research is to determing the degree of combustion of various CH4/H2 mixtures in a standard engine. Is that corrrect or are you also looking at ways to design a better engine to accommodate CH4/H2 mixtures and performance of the same mixture in various different engines?

The othe question I have is whether it is a wise to mix H2 and CH4 as a fuel since H2 burns very cleanly ideally with only H2O as a procuct but CH4 and other Hyrocarbons will also produce CO2 and perhaps CO. Based on your question I expect answering that question is outside of the scope of your current research.

My advice to you is that you think carefully about the goals of your research and design your experiments to meet your goals.

.

Thank you for the explanation

Interesting question

Interesting question

Interesting question

Hi Rick Manner,

Generally, natural gas is one of the best alternative fuels for internal combustion engine (ICE) which produces less carbon monoxide, carbon dioxide and hydrocarbon (CO, CO2 and HC) than that of gasoline and diesel fuels due to their lower carbon/hydrogen ratio and absence of fuel evaporation. The high octane number of natural gas (ROM up to 130) gives the engine high anti-knocking properties due to its high octane number and allows the ICE to operate at higher compression ratio, leading to the further improvement of both power output and thermal efficiency. However, their flame propagation rate is low and their auto-ignition temperature is high. However, hydrogen has a wider flammability limit, higher flame propagation velocity and faster combustion velocity. Furthermore, hydrogen has a short quenching distance in the edge of the piston, elevated thermal value and high diffusivity. Thus, the use of hydrogen in ICE fueled with natural gas is beneficial because CO, CO2 and HC are reduced. Since hydrogen does not contain carbon atom, CO, CO2 and HC emissions are also decreased.

Therefore, we want to test and simulate the ICE fueled with natural gas/hydrogen blends.

Thanks for your reply.

Regards,

Xiongbo

Duan Xiongbo ,

Thankyou for the explanation. Is this enginge you are using similar to gasoline engine with a spark plug (or equivalent) for ignition or is it more similar to a higher pressure diesel engine with a glow plug. I think a fuel with a RON of 130 would require a spark plug or equivalent for ignition.

I assume the goal of your research is to optimize a fuel for this particular engine design. Is this engine design similar to the design for the 25 Million+ natural gas vehicles currently in use around the world or is it a new engine concept?

Hi Rick Manner,

Yes, we are using the spark plug to ignite the natural gas/hydrogen blend due to the lower (13.6) compression ratio compared with diesel engine, while higher than the gasoline spark ignition engine. For second question, it is similar to the design for the natural gas vehicles.

thanks

Xiongbo

Duan Xiongbo ,

I think it is terrific that this test engine is able to gather all of this data about the mechanism of CH4/H2 combustion. It appears to me that your goal is to improve the undestanding of the chemsity more thoroughly in the hope that this knoweldge will lead to better future utilization of natural gas - possibly mixed with H2 as a transportation fuel.

Hi Rick Manner,

Hopefully, the hydrogen production, transportation and price could be achieved a trade-off in the near future. Then, the hydrogen can be wildly used in ICE.

thanks

Xiongbo

Thank you for the explanation