Modeling of the Supercritical Steam Generator of MHTGR in Engineering Simulator

The Modular High Temperature Gas-cooled Reactor (MHTGR) could realize higher efficiency and lower costs by developing the multi-modular high temperature gas-cooled reactors combined with supercritical steam turbine unit. The coupling effects among different modules are crucial to the designs and operation analyses of the multi-modular reactors. By establishing the engineering simulator for multi-modular reactors, the coupling effects can be studied and optimized to advance the reactor designs, due to the advantages of real-time calculations and coupled calculations. As key energy transfer equipment, the steam generator is very important to the reactor operation, and focused in the modeling of the engineering simulator system for multi-modular reactors. In this paper, the once-through steam generator consisted of helical coils was modeled and optimized in the vPower integrated simulation platform. From the detailed analyses of the distributions of temperatures, heat flux, and other parameters along the heat transfer tubes, it showed that the steam generator model well presented the supercritical water properties and heat transfer characteristics inside helical tubes. Also, the heat transfer correlations of the supercritical water inside helical tubes were investigated, discussed and also compared to test the uncertainty and influence to the whole steam generator model. And the results indicated that most heat transfer correlations showed similar results and had little effect on the primary side in the steady state operation condition. In future work, the model and heat transfer characteristics of the supercritical steam generator will be further tested in more transients and integrated into complete engineering simulator for multi-module reactors.

Numerical discretization analysis of a HTR steam generator model for the thermal-hydraulics code trace

For future high temperature reactor projects, e. g., for electricity production or nuclear process heat applications, the steam generator is a crucial component. A typical design is a helical coil steam generator consisting of several tubes connected in parallel forming cylinders of different diameters. This type of steam generator was a significant component used at the thorium high temperature reactor. In the work presented the temperature profile is being analyzed by the nodal thermal hydraulics code TRACE for the thorium high temperature reactor steam generator. The influence of the nodalization is being investigated within the scope of this study and compared to experimental results from the past. The results of the standard TRACE code are compared to results using a modified Nusselt number for the primary side. The implemented heat transfer correlation was developed within the past German HTR program. This study shows that both TRACE versions are stable and provides a discussion of the nodalization requirements.

The Steam Generator Water Level System Based on Nonlinear First Order ADRC Control

The Steam Generator with the characteristics nonlinear, time varying, and non-minimum phase whose water level will fluctuate significantly when it encounters inner disturbance or outside interference. For the above problem, the ADRC of steam generator will be designed in this article. Based on the dynamic characteristics of steam generator, equivalent the steam generator model to be the generalized first order system and establish control system based on nonlinear first order ADRC. The simulation results show that the proposed control strategy can achieve better control performance.

AP1000 Nuclear Reactor and Primary Loop Modeling Based on Relap5-3D and 3Keymaster Simulation Platform

In this paper, the advanced 3Keymaster simulation platform and RELAP5 simulation code are introduced. At the same time, the AP1000 nuclear reactor and primary loop modeling method is discussed in detail based on Remlap 5 and 3Keymaster simulation platform. The typical Relap5 nasalization cells of AP1000 nuclear reactor and primary loop system are showed in Fig.1. The Fig.2 shows the AP1000 reactor coolant system model. Fig.3 shows the AP1000 reactor core and pressure vessel model. Fig.4 shows the AP1000 nuclear reactor steam generator model.