Numerical and experimental study on the critical velocity and smoke maximum temperature in the connected area of branch tunnel

2021 ◽  
Author(s):  
Haihang Li ◽  
Fei Tang
Keyword(s):  
Experimental Study ◽  
Critical Velocity ◽  
Maximum Temperature ◽  
Connected Area

scholarly journals Numerical and Experimental Study of Lightning Stroke to BIPV Modules

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 748
Author(s):  
Xiaoyan Bian ◽  
Yao Zhang ◽  
Qibin Zhou ◽  
Ting Cao ◽  
Bengang Wei
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Coupling Model ◽  
Maximum Temperature ◽  
Lightning Stroke ◽  
Study Results ◽  
Pv Modules ◽  
New Type ◽  
Metal Frame ◽  
Current Flows

Building Integrated Photovoltaic (BIPV) modules are a new type of photovoltaic (PV) modules that are widely used in distributed PV stations on the roof of buildings for power generation. Due to the high installation location, BIPV modules suffer from lightning hazard greatly. In order to evaluate the risk of lightning stroke and consequent damage to BIPV modules, the studies on the lightning attachment characteristics and the lightning energy withstand capability are conducted, respectively, based on numerical and experimental methods in this paper. In the study of lightning attachment characteristics, the numerical simulation results show that it is easier for the charges to concentrate on the upper edge of the BIPV metal frame. Therefore, the electric field strength at the upper edge is enhanced to emit upward leaders and attract the lightning downward leaders. The conclusion is verified through the long-gap discharge experiment in a high voltage lab. From the experimental study of multi-discharge in the lab, it is found that the lightning interception efficiency of the BIPV module is improved by 114% compared with the traditional PV modules. In the study of lightning energy withstand capability, a thermoelectric coupling model is established. With this model, the potential, current and temperature can be calculated in the multi-physical field numerical simulation. The results show that the maximum temperature of the metal frame increases by 16.07 °C when 100 kA lightning current flows through it and does not bring any damage to the PV modules. The numerical results have a good consistency with the experimental study results obtained from the 100 kA impulse current experiment in the lab.

Experimental Study on Burning Process and Characteristic of Sodium Columnar Fire

2014 ◽  
Author(s):  
Ye-xin Tang ◽  
Zhi-gang Zhang ◽  
Ming Guo ◽  
Shu-bin Sun
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Stainless Steel ◽  
Temperature Field ◽  
Liquid Sodium ◽  
Maximum Temperature ◽  
Radial Temperature ◽  
Burning Process ◽  
Short Time ◽  
Hydrodynamic Effects

A variety of sodium fire generated by the leakage of liquid sodium in the FBR is common. This paper focuses on the burning process and characteristics of sodium fire in a columnar flow. About 290°C liquid sodium was injected into a 7.9 m3 stainless steel cylindrical combustion space to shape the sodium columnar fire by 0.2 MPa high pressure nitrogen. The data of temperature field for the study of burning characteristic of sodium columnar fire have been collected by the temperature acquisition system located in the combustion space. The sodium flow maintains the columnar shape at first, and disperses by hydrodynamic effects on its way down. About 64s after the initiating time of sodium ejection for this experiment, the maximum temperature of the area close to the ejection center reaches over 1200°C. And the maximum temperature appears at the space of 1–1.5m from the plate. But the high temperature lasts for a short time and reduces rapidly. The radial temperature of the area far from the sodium flow is relatively low and generally about 200°C, and maximally about 350 °C. This study is helpful to evaluate the combustion characteristics and burning process of the sodium fire in the sodium-related facilities.

scholarly journals Design and Validation of Thermal Insulation for Deep-sea Fluid Sampler of Jiaolong Human Occupied Vehicle

2021 ◽  
Vol 2095 (1) ◽  
pp. 012070
Author(s):  
Kaiben Yu ◽  
Le Zong ◽  
Shengqi Yu ◽  
Qingjian Meng ◽  
Baohua Liu
Keyword(s):  
Experimental Study ◽  
Thermal Insulation ◽  
Deep Sea ◽  
Silica Aerogel ◽  
Simulation Analysis ◽  
Maximum Temperature ◽  
Vehicle Simulation ◽  
Variation Characteristics ◽  
Insulation Effect ◽  
Insulation Performance

Abstract In this paper, a thermal insulation structure with silica aerogel felt as filler material was designed for the requirements of deep-sea fluid thermal insulation sampling technology for Jiaolong human occupied vehicle. Simulation analysis of thermal insulation performance was carried out and an experimental prototype was developed for the thermal insulation structure. Experimental study on thermal insulation performance was conducted with the variation characteristics of the operation environment for Jiaolong human occupied vehicle being taken into account. Results show that the silica aerogel felt with a thickness of 30 mm filled in the radial space between the inner and outer cylinders can achieve the expected thermal insulation effect during the diving-sampling-transferring process, with maximum temperature rise of 8.5 °C, and can meet the requirements of deep-sea fluid thermal insulation sampling technology.

scholarly journals EXPERIMENTAL STUDY OF INSULATOR USING ASBESTOS COATING MATERIALS WITH DIFFERENT TEMPERATURE

2020 ◽  
Vol 4 (10) ◽  
pp. 114-118
Author(s):  
S.K. Mahobia ◽  
G.R. Kumrey
Keyword(s):  
Experimental Study ◽  
Coating Material ◽  
Maximum Temperature ◽  
Stable Point ◽  
Coating Materials ◽  
Distribution Line

In this paper we are study about insulator with asbestos coating material. The applied loads are as 1000 Watts, 2000Watts, 3000Watts, 4000Watts, and 5000Watts. The coated insulators are used in distribution Line, in this study we are achieving the maximum Temperature and also achieving the stable point of using insulator.

Experimental Study on Non-Pulverized Wood Biomass Combustion With a New Three-Way Swirling Combustion Cyclone Combustor

2019 ◽  
Vol 12 (3) ◽  
Author(s):  
Kangil Choe ◽  
Yangho Lee ◽  
Soongul Lee ◽  
Michael Weedon
Keyword(s):  
Experimental Study ◽  
Removal Rate ◽  
Maximum Temperature ◽  
Biomass Combustion ◽  
Slag Formation ◽  
Wood Biomass ◽  
Complete Combustion ◽  
Cyclone Combustor ◽  
Combustion Technology ◽  
Future Work

Abstract An experimental study presents a new innovative cyclone combustor, known as the three-way swirling combustion (TSC), utilizing non-pulverized wood biomass. The study shows that the combustor reached near-complete combustion, as evident in the measurements of CO and NOx emissions, and the excess air ratio. It also demonstrates the unique features of the TSC combustor, which includes an air curtain insulation effect with a high ash removal rate that reduces clinker and slag formation, alongside a chamber that does not need a refractory brick. It compares against conventional combustion technology, such as the stoker and the fluidized bed in terms of the amount of emission gases, maximum temperature, and excessive air ratio. Six geometrical and operational design criteria of the TSC for wood biomass combustion are identified for future work of design optimization. Ultimately, the implementation of the TSC for non-pulverized wood biomass and possibly for other biomass holds great potential for economically and technically beneficial incineration and power generation.

Sign in / Sign up

Export Citation Format

Share Document