By comparing the physical properties of natural gas and hydrogen gas

the combustion chamber structure of ring tube type gas turbine was improved after the gas turbine firing hydrogen instead of natural gas

through thermodynamic design calculation methods.It suggests that such structural parameters as the cavity length

the diffuser's length

the flame tube diameter and length of the combustor should be changed to 1.414 times of that in the raw combustor when burning natural gas.The maximum cross-sectional area of the combustion chamber should be changed into 2times of its original value.The distance from the primary holes and fill holes to the cyclone should be changed into 1.414 times of the original value.The results show that

changing the fuel has different influences on the combustor's structure.To realize the optimal working condition and combustion efficiency

the degree of the improvements for the combustion chamber's different structures should be coordinated.