Modeling of hydrogen and methane dispersion process in pipeline using computational fluid dynamic (cfd)

摘要

In this era of globalisation and modernisation, natural gas is becoming one of the most wanted natural resources in many industries basically for cooling and heating purpose. Due to the high demand, transporting natural gas via pipeline is the best way to fulfil the demand for natural gas. Hence, it is very important to transport natural gas via pipeline with safety precaution. Meanwhile, in future hydrogen gas has the capability to become one of the important energy resources for many industries. This will create an economy call hydrogen economy. It is expected hydrogen can become main source of energy to replace fossil fuels and can be transported via pipeline to meet customers demand. However, the physical properties of methane and hydrogen are totally different and also the safety to supply hydrogen via pipeline is taken into consideration. Therefore, this paper is aim to study about the dispersion effects of hydrogen and methane and do comparison among both gases. In this paper we will be using Computational Fluid Dynamic (CFD) software to detect leakage when transporting methane and hydrogen gas. The model that will be use is environmental area 240 m wide and 80 m high. Two 30 m wide and 20 m high buildings are placed to represent factory building. Underneath, a part of pipeline is modelled as a source where methane and hydrogen gases are released. The 2 m diameter pipeline is filled with either hydrogen gas or methane gas at pressure 11 bars. The leak in the pipe is located at x= 0 m. This study will be done by using different scenarios at different time interval which is at time 1s and 7.5s and different wind speed; 0 m/s, 5m/s, 10m/s ad 15 m/s. The results show that, the rate of dispersion of hydrogen is higher compare to methane and methane tends to be more on the surface of the ground where ignition is possible. Using Computational Fluid Dynamic (CFD) is the best method to study about leakage of methane and hydrogen gas due to low cost involve rather than building up pipeline network to test the situation which is something irrational to be done. From this study, it can be clearly seen that the rate of dispersion of hydrogen will be higher compare to methane due to the gases properties like density and buoyancy force. Thus, it is feasible to transport hydrogen via pipeline due to higher dispersion effect compare to methane