Feedback control optimization of a single fluid heat exchanger or nuclear reactor

1968 ◽  
Vol 7 (1) ◽  
pp. 40-48
Author(s):  
R.G. Watts ◽  
R.J. Schoenhals
Author(s):  
P C Chiu ◽  
E H K Fung

A triple heat exchanger, so called because there are three heat exchange processes taking place in it, was built to simulate the system behaviour of a nuclear reactor power plant or a solar heating plant which is characterized by the two circulating loops of the fluid flow. Experiments were carried out to study the temperature transients under disturbances in secondary fluid inlet temperature and power output from immersion heaters. Numerical results were obtained from the weighted residual formulation of the proposed dynamic model and they were shown to be in general agreement with the two sets of experimental responses.


Author(s):  
Zhili Feng ◽  
Weiju Ren

To investigate the possibility of joining oxide-dispersion-strengthened (ODS) alloys while preserving the dispersion for high temperature strength in potential applications to Gen IV nuclear reactor compact heat exchanger, solid-state welding of ODS alloy sheets using friction stir welding (FSW) was studied. Butt weld was successfully produced, and the weld and base metals were characterized using optical, scanning electronic, and transmission electronic microscopes, as well as energy dispersion x-ray spectrum. Microhardness mapping was also conducted over the weld region. Analyses indicate that the distribution of the strengthening oxides was preserved in the weld. Decrease in microhardness of the weld was observed but was insignificant. The preliminary results seem to confirm the envisioned feasibility of FSW application to ODS alloy joining. Further investigation activities are suggested for providing better mechanistic understanding and processing control for applications to Gen IV nuclear reactor systems.


2015 ◽  
Vol 36 (1) ◽  
pp. 3-18
Author(s):  
Adam Fic ◽  
Jan Składzień ◽  
Michał Gabriel

Abstract Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle), which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle). The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.


2004 ◽  
Vol 147 (2) ◽  
pp. 240-257 ◽  
Author(s):  
Roman Shaffer ◽  
Weidong He ◽  
Robert M. Edwards

Author(s):  
Valery Ponyavin ◽  
Sundaresan Subramanian ◽  
Clayton Ray DeLosier ◽  
Yitung Chen ◽  
Anthony E. Hechanova ◽  
...  

This paper presents the stress analysis of the offset strip-fin type compact high temperature heat exchanger for use in the cooling cycle of an advanced nuclear reactor for hydrogen production by the sulfur iodine thermo-chemical cycle. Three different geometry types of heat exchangers were considered: geometry with rectangular fins; geometry with rounded fins and geometry with rounded fins which include manufacturing geometrical effects (fins with roundings on their bases). The material of the heat exchanger is liquid silicon impregnated carbon composite. The two working fluids for the heat exchanger are helium gas and molten salt with maximum temperature about 1000°C. The finite element code ANSYS 9.0 was used for the simulations. The boundary conditions for temperature and pressure were obtained as results of CFD and heat transfer calculations of the heat exchanger using the finite volume code FLUENT 6.1.18 The obtained results will be used for further optimization of the high temperature heat exchanger geometry.


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