Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products

Abstract

In this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight ratio and efficiency for diesel and gas turbine power modules of various capacities. Mathematical modeling methods are used to analyze the parameters of an alternative gas turbine unit based on steam conversion of the associated gas, and the estimated efficiency of the energy module is shown to be 50%. In the modeling of the burning processes, the UGT 25000 serial low emission combustor is considered, and a detailed analysis of the processes in the combustor is presented, based on the application of a 35-reaction chemical mechanism. We confirm the possibility of efficient combustion of associated gas steam conversion products with different compositions, and establish that stable operation of the gas turbine combustor is possible when using fuels with low calorific values in the range 7–8 MJ/kg. It is found that the emissions of NOx and CO during operation of a gas turbine engine on the associated gas conversion products are within acceptable limits.

Keywords

• thermo-chemical heat recovery
• gas turbine engine
• associated gas
• combustor