At present

research on combustion of gaseous fuels mixed with inert gas is a hot issue. In this paper

the high pressure combustion characteristics of natural gas mixed with CO_2 were numerically studied by the Fluent software. The mixtures of natural gas and carbon dioxide with blending ratio of 0

0.2

0.4 and 0.64 were selected to perform high pressure combustion at 0.1 MPa

1 MPa

2 MPa and 4 MPa. Moreover

numerical simulation on high temperature area of the combustion and NO_x emission characteristics of the mixtures were carried out. The results show that

at the same pressure

the length of the 1 500 K high temperature section of co-combustion of natural gas and CO_2 gradually decreases with the increasing blending ratio. With the same CO_2 blending ratio

the length and the maximum width of the 1 500 K high-temperature section increases with the pressure. In addition

with the same mixing ratio

the produced NO_x increases with the pressure under conditions

while at the same pressure

it increases first and then decreases with the blending ratio. Moreover

the produced amount of NO_xchanged more dramatically with the increasing pressure.