PRESSURE DROP AND HEAT TRANSFER MEASUREMENTS OF THE ONCE THROUGH STEAM GENERATOR HELICAL TUBE BUNDLES OF HIGH TEMPERATURE GAS-COOLED REACTORS

2018 ◽  
Author(s):  
Xiaowei Li ◽  
Jiaqing Zhao ◽  
Xinxin Wu ◽  
Xiaowei Luo
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Pressure Drop ◽  
Steam Generator ◽  
Helical Tube ◽  
Tube Bundles ◽  
High Temperature Gas

Modeling of the Supercritical Steam Generator of MHTGR in Engineering Simulator

2014 ◽  
Author(s):  
Dan Liu ◽  
Jun Sun ◽  
Zhe Sui ◽  
Chun-lin Wei ◽  
Yu-liang Sun
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Steam Generator ◽  
Supercritical Water ◽  
Heat Transfer Characteristics ◽  
Coupling Effects ◽  
Transfer Characteristics ◽  
Helical Tubes ◽  
Steam Generator Model ◽  
High Temperature Gas

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.

scholarly journals A Parametrical Study on Convective Heat Transfer between High-Temperature Gas and Regenerative Cooling Panel

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1784
Author(s):  
Jiangyu Hu ◽  
Ning Wang ◽  
Jin Zhou ◽  
Yu Pan
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Temperature ◽  
Thermal Protection ◽  
Flow Direction ◽  
Heated Surface ◽  
Heat Transfer Process ◽  
Cocurrent Flow ◽  
Regenerative Cooling ◽  
High Temperature Gas

Thermal protection is still one of the key challenges for successful scramjet operations. In this study, the three-dimensional coupled heat transfer between high-temperature gas and regenerative cooling panel with kerosene of supercritical pressure flowing in the cooling channels was numerically investigated to reveal the fundamental characteristics of regenerative cooling as well as its influencing factors. The SST k-ω turbulence model with low-Reynolds-number correction provided by the pressure-based solver of Fluent 19.2 is adopted for simulation. It was found that the heat flux of the gas heated surface is in the order of 106 W/m2, and it declines along the flow direction of gas due to the development of boundary layer. Compared with cocurrent flow, the temperature peak of the gas heated surface in counter flow is much higher. The temperature and heat flux of the gas heated surface both rises with the static pressure and total temperature of gas. The heat flux of the gas heated surface increases with the mass flow rate of kerosene, and it hardly changes with the pressure of kerosene. Results herein could help to understand the real heat transfer process of regenerative cooling and guide the design of thermal protection systems.

Active Chemistry Control for Coolant Helium Applying High-Temperature Gas-Cooled Reactors

2008 ◽  
Author(s):  
Nariaki Sakaba ◽  
Shimpei Hamamoto ◽  
Yoichi Takeda
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Chemical Composition ◽  
Structural Integrity ◽  
Carbon Deposition ◽  
Control Technology ◽  
Equilibrium Study ◽  
Intermediate Heat Exchanger ◽  
High Temperature Gas

Lifetime extension of high-temperature equipment such as the intermediate heat exchanger of high-temperature gas-cooled reactors (HTGRs) is important from the economical point of view. Since the replacing cost will cause the increasing of the running cost, it is important to reduce replacing times of the high-cost primary equipment during assumed reactor lifetime. In the past, helium chemistry has been controlled by the passive chemistry control technology in which chemical impurity in the coolant helium is removed as low concentration as possible, as does Japan’s HTTR. Although the lifetime of high-temperature equipment almost depends upon the chemistry conditions in the coolant helium, it is necessary to establish an active chemistry control technology to maintain adequate chemical conditions. In this study, carbon deposition which could occur at the surface of the heat transfer tubes of the intermediate heat exchanger and decarburization of the high-temperature material of Hastelloy XR used at the heat transfer tubes were evaluated by referring the actual chemistry data obtained by the HTTR. The chemical equilibrium study contributed to clarify the algorism of the chemistry behaviours to be controlled. The created algorism is planned to be added to the instrumentation system of the helium purification systems. In addition, the chemical composition to be maintained during the reactor operation was proposed by evaluating not only core graphite oxidation but also carbon deposition and decarburization. It was identified when the chemical composition could not keep adequately, injection of 10 ppm carbon monoxide could effectively control the chemical composition to the designated stable area where the high-temperature materials could keep their structural integrity beyond the assumed duration. The proposed active chemistry control technology is expected to contribute economically to the purification systems of the future very high-temperature reactors.

HTGR Component Test Facility (CTF) Feasibility Study for NGNP

2008 ◽  
Author(s):  
Jan P. van Ravenswaay ◽  
Jacques Holtzhausen ◽  
Jaco van der Merwe ◽  
Kobus Olivier ◽  
Riaan du Bruyn ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Oil Recovery ◽  
Recovery Process ◽  
Initial Energy ◽  
Test Facility ◽  
Design Data ◽  
Component Test ◽  
Maintenance And Inspection ◽  
High Temperature Gas

The Next Generation Nuclear Plant (NGNP) Project is a US-based initiative led by Idaho National Laboratories to demonstrate the viability of using High Temperature Gas-Cooled Reactor (HTGR) technology for the production of high temperature steam and/or heat for applications such as heavy oil recovery, process steam/cogeneration and hydrogen production. A key part of the NGNP Project is the development of a Component Test Facility (CTF) that will support the development of high temperature gas thermal-hydraulic technologies as applied in heat transport and heat transfer applications in HTGRs. These applications include, but are not limited to, primary and secondary coolants, direct cycle power conversion, co-generation, intermediate, secondary and tertiary heat transfer, demonstration of processes requiring high temperatures as well as testing of NGNP specific control, maintenance and inspection philosophies and techniques. The feasibility of the envisioned CTF as a development and testing platform for components and systems in support of the NGNP was evaluated. For components and systems to be integrated into the NGNP full scale or at least representative size tests need to be conducted at NGNP representative conditions, with regards to pressure, flow rate and temperature. Typical components to be tested in the CTF include heat exchangers, steam generators, circulators, valves and gas piping. The Design Data Needs (DDNs), Technology Readiness Levels (TRLs) as well as Design Readiness Levels (DRLs) prepared in the pre-conceptual design of the NGNP Project and the NGNP lifecycle requirements were used as inputs to establish the CTF Functional and Operating Requirements (F&ORs). The existing South African PBMR test facilities were evaluated to determine their current applicability or possible modifications to meet the F&ORs of the CTF. Three concepts were proposed and initial energy balances and layouts were developed. This paper will present the results of this CTF study and the ongoing efforts to establish the CTF.

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