Time-dependent quasi-one-dimensional numerical code has been developed to investigate (1)the thermal and fluid-dynamical behavior in the closed loop MHD power generation facility and (2)the Start-up operating characteristics of the closed loop facility. It is essential to know the transient and steady state operating characteristics of the closed loop facility with a view of running the system safely for the future experimental operations. There are many operating parameters to be controlled to attain the required gas temperature of 1900[K]. The precise prediction of those controling parameters are made by carrying out numerical simulations. The energy balance of the closed loop facility and it's steady state operating characteristics are presented in this paper. Moreover, benefical suggestions on the start-up operation of the closed loop has been given.