Calculation method for gas temperature from combustor outlet based on gas composition

According to different gas compositions in combustor at different temperatures, two calculation methods for predicting gas temperature by establishing different gas models were proposed. Based on the theory of substance conservation, chemical equilibrium and energy conservation, the equations of temperature calculation were established. According to different expressions of the energy conservation equation, the average specific heat capacity of constant pressure method and the enthalpy value method were given, two mathematical methods for solving nonlinear equations were presented at the same time, including three variables iterative method and Newton method. VB (Visual Basic) was used to compile test program to realize temperature algorithm. The calculation example was enumerated to compare the difference between the two algorithms. The result shows that the difference of gas temperatures obtained by the two methods is greater with the increase of oil gas ratio, the result acquired by the high temperature algorithm considering thermal dissociation is smaller, and the reason is that the molar fraction of the dissociated components in the gas increases with the temperature rise, and the actual heat release decreases, leading to the decrease in gas temperature. Therefore when the gas temperature is higher, the high temperature algorithm is more in line with the actual combustion situation.