Abstract
A new algorithm is implemented to represent formation and decomposition of methane hydrate particles during operation of the production system in the Discrete Element Method with the Coarse Grid Thermal-Fluid Coupling Scheme, which is developed by one of the authors. The phase of discrete particles changes at interface between the particles and continuous phase. The phase-change rate depends on the fugacity from the Pressure-Temperature diagram around the circumstance. The scheme is also enable one to simulate the process of agglomeration from hydrate particles and bonding to equipments of the production system by devising a bonding model. Several simulations were conducted to verify the scheme on the momentum and the thermal energy exchange between particles and continuous phase. Also parametric studies are conducted to examine the algorithm of phase-change by changing phase-change rate constant and the Pressure-Temperature diagram. Further, particles agglomeration in a duct is expressed using the bonding model. It was verified that the momentum and the thermal energy between particles and continuous phase are exchanged correctly with phase-change. Also the scheme was able to represent phase-change of methane hydrate and particle agglomeration. As a result, it was found that the scheme is able to be a useful tool to examine the flow assurance without blockage by methane hydrate in the production system if the parameters used in simulations are tuned up.
