Investigation of thermal coupling model for evaporation process in a slightly inclined tube and tube bundles

摘要

Safety of Nuclear Power Plant is an essential part in the development process of nuclear power plants. More and more Generation III+ reactor designs rely on passive safety system to increase the plant safety standards and to reduce investment costs. Passive Containment cooling systems like the Containment Cooling Condenser (CCC) of the KERENA reactor design plays an important role in safety issue of Generation III+ reactor at Nuclear Power Plant. As part of the emergency cooling chain they remove decay heat from the Containment and transfer it to the main heat sink for accidental management represented by the Shielding and Storage Pool Vessel (SSPV). Corresponding to CCC, the test facility GENEVA at Technical University of Dresden (TUD) was set up to investigate the stability and instability of heat transfer mechanism as well as natural circulation phenomena with heat input by steam condensation in steam chamber. A variety of transient experiments with input power of the evaporators ranging from 15kW up to 40 kW for condensation tube were performed. In this work, the transient thermal coupling model of evaporation process inside steam chamber is modeled with thermal hydraulic system code. The performance of the code is assessed comparing experimental and calculated data. The heat transfer models between the fluids and the structure as well as interphase heat transfer models are analyzed. Goal is to optimize the capability to predict thermal coupling parameters, particularly heat transfer coefficient due to pressure change inside the pipe. Model will be derived that allow to enhance the prediction capability of system codes.