Electronic Thesis and Dissertation Repository

Degree

Master of Engineering Science

Program

Mechanical and Materials Engineering

Supervisor

Prof. Chao Zhang

2nd Supervisor

Prof. Jin Jiang

Joint Supervisor

Abstract

In this study, the methodology to construct a control system based on computational fluid dynamics (CFD) simulations is developed for supercritical water cooled reactor (SCWR). The CFD model using Reynolds Stress Model (RSM) and k-w SST model is validated with the experimental cases of steady state and vertically up flowing supercritical water in circular tubes for normal heat transfer and deteriorated heat transfer (DHT) cases. This model is extended to simulate the transient thermal-hydraulic behaviour of supercritical fluid flow and heat transfer, and the results are also compared with the 1-D numerical model, THRUST. The DHT phenomenon is investigated using the turbulence kinetic energy (TKE) and velocity distribution and its effect on heat transfer. A correlation is reported between the TKE and velocity profiles and heat transfer phenomenon at supercritical condition. The non-dimensional buoyancy and acceleration parameters are also used to predict the occurrence of DHT in the supercritical water flow in circular tubes.

In the process of developing a control system for Canadian version of SCWR, system identification method is used to develop the linear dynamic models based on non-linear CFD simulations. Considering the strong cross-coupling between the inputs and outputs of the SCWR, multiple input and multiple output (MIMO) system is decoupled and is converted to several single input and single output (SISO) systems using pre-compensator. Based on the decoupled SISO systems, loop compensator is developed for the control and stability of the reactor.


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