Analysis of Instability for OTSG by Using Multivariable Frequency Domain Method

A new method for analyzing the problem of the thermal-hydrodynamic instability of OTSG (once-through steam generator) with multiple boiling channels is presented in this paper. The mothod is based on modern frequency domain theory and is more efficient for analyzing the instability of OTSG with coupling interactions and complicated boundary conditions than the usually used single variable method. A mathematical model for a OTSG is derived from the foundamental equations by use of the small perturbation and Laplace-transform techniques. The stable boundary and parametric effects on the stability of the system are evaluated with a computer code. Numerical examples are given in the paper and the predictions of the model are in good agreement with the experimental results.