Decreasing capability of the degassing systems at lakes Nyos and Monoun (Cameroon): a new gas removal system applied to Lake Monoun to prevent a future limnic eruption

The isotope Xe-135 has a large thermal neutron absorption cross section and is considered to be the most important fission product. A very small amount of such neutron poison may significantly affect the reactor reactivity since they will absorb the neutrons from chain reaction, therefore monitoring their atomic density variation during reactor operation is extremely important. In a molten reactor system, Xe-135 is entrained in the liquid fuel and continuously circulates through the core where the neutron irradiation functions and the external core where only nuclei decay occurs, at the same time, an off-gas removal system operates for online removing Xe-135 through helium bubbling. These unique features of MSR complicate the Xe-135 dynamic behaviors, and the calculation method applied in the solid fuel reactor system is not suitable. From this point, we firstly analytically deduce the nuclei evolution law of Xe-135 in the flowing salt with an off-gas removal system functioning. A study of Xe-135 dynamic behavior with the core power change, shutdown, helium bubbling failure and startup then is conducted, and several valuable conclusions are obtained for MSR design.

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Economic and Thermodynamic Analysis for Preliminary Design of Dry Steam Geothermal Power Plant (GPP) with Multifarious Gas Removal System (GRS) in Kamojang, West Java, Indonesia

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/42/1/012011 ◽

2016 ◽

Vol 42 ◽

pp. 012011 ◽

Cited By ~ 3

Author(s):

Aloysius Damar Pranadi ◽

Sihana ◽

Kutut Suryopratomo ◽

Fiki Rahmatika Salis

Keyword(s):

Power Plant ◽

Thermodynamic Analysis ◽

Preliminary Design ◽

West Java ◽

Geothermal Power Plant ◽

Gas Removal ◽

Geothermal Power ◽

Removal System

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Study on the Air Core Formation of a Gas–Liquid Separator

Journal of Fluids Engineering ◽

10.1115/1.4030198 ◽

2015 ◽

Vol 137 (9) ◽

Cited By ~ 31

Author(s):

Junlian Yin ◽

Jingjing Li ◽

Yanfei Ma ◽

Hua Li ◽

Wei Liu ◽

...

Keyword(s):

Reynolds Number ◽

Reynolds Numbers ◽

Back Pressure ◽

Core Formation ◽

Swirl Number ◽

Air Core ◽

Gas Removal ◽

Thorium Molten Salt Reactor ◽

Liquid Separator ◽

Removal System

The gas–liquid separator is a key component in the gas removal system in thorium molten salt reactor (TMSR). In this paper, an experimental study focusing on the gas core formation in the gas–liquid separator was carried out. We observed that formation of the air core depends primarily on the back pressure in the separator. Gas core formation was visualized for a range of back pressures, swirl numbers, and Reynolds numbers. Analysis of flow patterns indicated that gas core formation may be defined as four stages: “air core with suction,” “tadpole-shaped core,” “cloudy core,” and “rod core.” When rod core is achieved, gas bubbles will be separated completely and that particular back pressure is defined as critical back pressure. The critical back pressure depends on swirl number and Reynolds number. The trends how the critical back pressures vary with the Reynolds number and the swirl number were analyzed.

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Performance evaluation of a bubble generator and a bubble separator designed for the gas removal system of a small thorium molten salt reactor

Chinese Journal of Chemical Engineering ◽

10.1016/j.cjche.2019.01.035 ◽

2020 ◽

Vol 28 (5) ◽

pp. 1250-1259 ◽

Cited By ~ 1

Author(s):

Licheng Sun ◽

Liang Zhao ◽

Min Du ◽

Zhengyu Mo ◽

Jiguo Tang ◽

...

Keyword(s):

Performance Evaluation ◽

Molten Salt ◽

Molten Salt Reactor ◽

Gas Removal ◽

Thorium Molten Salt Reactor ◽

Removal System

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Computational and Experimental Study of Gas Bubbles Removal in a Microfluidic System

ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2015-48561 ◽

2015 ◽

Cited By ~ 1

Author(s):

Hamed Gholami Derami ◽

Jeff Darabi

Keyword(s):

Flow Direction ◽

Gas Bubbles ◽

Microfluidic System ◽

Operating Conditions ◽

Hydrophobic Membrane ◽

Fluidic Channel ◽

Ansys Fluent ◽

Gas Removal ◽

Bubble Removal ◽

Removal System

Formation of unwanted bubbles is one the main issues in biomicrofluidics-based applications such as lab-on-a-chip devices, and adversely affects the performance of these systems. In this work we report a simple and efficient method for removing gas bubbles from liquid filled microchannels. This bubble removal system consists of a cavity on which a hydrophobic membrane is bonded parallel to the main fluidic channel to vent gas bubbles normal to the flow direction. A T-junction configuration is used to generate gas bubbles prior to entering the bubble removal cavity. A finite volume-based computational model is developed using ANSYS FLUENT to simulate gas removal characteristics of the system. The effects of various geometric parameters and operating conditions are studied both through numerical simulations and experimentally.

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Experimental Study of a Gas Separator for MSR Gas Removal System

Volume 2: Plant Systems, Construction, Structures and Components; Next Generation Reactors and Advanced Reactors ◽

10.1115/icone21-16124 ◽

2013 ◽

Cited By ~ 1

Author(s):

Nana Zhang ◽

Changqi Yan ◽

Licheng Sun

Keyword(s):

Pressure Drop ◽

Molten Salt ◽

Separation Efficiency ◽

Working Fluid ◽

Local Pressure ◽

Local Flow ◽

Gas Removal ◽

Gas Separator ◽

High Separation ◽

Removal System

An independent gas removal system was firstly put up by Oak Ridge National Laboratory (ORNL) for Molten Salt Breeder Reactor (MSBR) to remove fission gas such as Xenon etc. from molten salt (LiF–BeF–UF), where the gas separator is a key equipment for which high separation efficiency and low pressure drop are required. Swirl vanes and recovery vanes are installed around the inlet and outlet of the gas separator. With reference to the design of ORNL, a new gas separator was designed for a conceptual design of a small molten salt research reactor. An experimental loop was also fabricated to test the local pressure drop and separation efficiency of the new designed gas separator using of water and air as working fluid. The separation efficiency is measured by comparing the gas flow rate from the bubble generator and that at the outlet of the separator using of high speed video camera. The tests were conducted with the water flow rates covering 10–30 m3/h and an average void fraction of 0.3%. Besides, the shape of gas cores is found necessary to estimate the working performance of gas separators. High separation efficiency comes with a stable and straight gas core, and the gas will be taken off from two ends of the gas separator. What’s more, the result shows that low concentration of gas does not increase the pressure drop compared with the condition of liquid only, except when it exceeds a certain level. Finally, local flow resistance of the gas separator was also obtained under low gas concentration condition, showing that the resistance factor is nearly unvaried with a value of 5.

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