Numerical Study on Different Series Modes of Jet Fan in a Longitudinal Tunnel Ventilation System

Pei, Guihong; Pan, Jie

doi:10.1155/2014/194125

Cited by 11 publications

(4 citation statements)

References 4 publications

(10 reference statements)

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“…Fan Jianguo et al [5], Li Xiaofei et al [6] and Hu Kang et al [7] used CFD numerical methods to study the impact of the longitudinal spacing of jet fans on the air flow field and pressure distribution, and obtained a reasonable range and the best distance of the longitudinal spacing. Through numerical simulation and theoretical calculation, Guihong Pei et al [8] believed that the tunnel ventilation effect was mainly affected by the spacing of adjacent fans and the combination mode of operating fans. Zhao Dongping et al [9] used network algorithm and CFD numerical analysis method to obtain the optimal spatial layout of jet fans for tunnel disaster prevention ventilation.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the influence of the layout of jet fans on the ventilation effect in tunnel

Ding¹

2023

International Conference on Computer, Artificial Intelligence, and Control Engineering (CAICE 2023)

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In order to optimize the spatial layout of jet fans in the tunnel, the influence of the location of jet fans on the air flow and vehicle exhaust in the tunnel are studied in this paper. Firstly, the three-dimensional physical model of tunnel and mathematical model of jet fan ventilation and vehicle exhaust emissions are established. Then the effects of fan longitudinal spacing and transverse spacing on the velocity distribution, pressure-rise coefficient of jet fans and vehicle exhaust in the tunnel are studied through CFD numerical simulation, so as to obtain the optimal layout parameters. The results show that when the fan longitudinal spacing is 110-m to approximately 140-m, the pressure-rise coefficients of fans are 0.880 to approximately 0.891, which increase first and then decrease as the longitudinal spacing increasing, and the optimal longitudinal spacing is 130-m. When the transverse spacing of fans are 1.68-m, 2.24-m, 2.8m and 3.36-m, the pressure-rise coefficients of fans are 0.918 to approximately 0.936, which increase first and then decrease as the transverse spacing increasing. The transverse spacing of fans should be set between 2.24-m and 3.36-m, and the pressure-rise coefficients can reach above 9.2, and the optimal transverse spacing is 2.8-m. When the jet fans are arranged horizontally and longitudinally, the concentration of CO in the tunnel presents zigzag fluctuations. When the transverse spacing of fans are 1.68-m to approximately 3.36-m and the longitudinal spacing are 110-m approximately 130-m, the concentration of CO in the tunnel is far lower than the safety concentration. The research results can be used for reference and guidance in the layout and installation of jet fans in tunnels.

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Section: Introductionmentioning

confidence: 99%

Numerical study on the influence of the layout of jet fans on the ventilation effect in tunnel

Ding¹

2023

International Conference on Computer, Artificial Intelligence, and Control Engineering (CAICE 2023)

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“…It can be seen that the efficient ventilation system plays a good role in optimizing the air quality in the tunnel and reducing the concentration of harmful gases. Therefore, based on the original ventilation design of Zhongyuan tunnel, fluent software is used, relying on K-ε turbulence model, establish a three-dimensional model of the tunnel, simulate the operation effects of different combinations of four fans in the tunnel, and finally determine the new combination form of ventilation fans composed of a group of double parallel fans and two groups of single fans, which is 5.7% higher than the tunnel air flow velocity in the original ventilation design (Pei and Pan, 2014). In addition to the influence of the distance between the air outlet of the air duct and the tunnel face, the air flow field in the tunnel is also affected by other main influencing factors, such as the excavation mode of the tunnel face, the length and height of the steps when the step method is used for construction, etc.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis and control technology of gas accumulation in a large-scale specially-shaped tunnel passing through coal bearing strata

Shu

Fan

et al. 2023

Front. Earth Sci.

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To solve the construction ventilation problem of super long (length greater than 10000 m) tunnel passing through discrete lenticular gas bag tunnel under complex working conditions in carbonaceous shale stratum, relying on the construction of Banzhulin tunnel of the new Xuyong-Bijie Railway (Sichuan-Yunnan). Using the finite element analysis software, the flow field distribution of the tunnel return air flow in the case of simultaneous excavation of multiple working faces is simulated, and the formation position and influence range of the vortex area which is easy to form gas accumulation are analyzed. On this basis, the technical team developed the PLC uninterruptible self starting ventilation power supply control program. By comparing the changes in the time required for ventilation power supply failure before and after the adoption of this technology, and the comparison of the gas concentration in the return air flow within a relatively short time of the failure, it is proved that this technology reduces the fault response time to 15.74% of the original time, and can well avoid gas accumulation within the failure time, It provides some reference for similar engineering construction.

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“…A relatively simple CFD model of the free jet fan was proposed and validated. Moreover, the different series modes of jet fans in a longitudinal tunnel ventilation system were investigated by Guihong Pei and Jie Pan (2014) [3]. When most operational fans are located near the tunnel entrance, it is more conducive to increase the velocity and pressure inside the tunnel.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of the Effects of the Jet Fan Speed, Heat Release Rate and Aspect Ratio on Smoke Movement in Tunnel Fires

et al. 2020

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In this study, the effects of the jet fan speed, heat release rate and aspect ratio on smoke movement in tunnel fires have been investigated. The jet fan speed was changed from 6.25 (25%) to 12.5 m/s (50%), 18.75 m/s (75%), and 25 m/s (100%). The heat release rate was set up from 3.9 to 6 MW and 16 MW, the aspect ratio was changed from 0.6 to 1 and 1.5, respectively. The lower the jet fan speed is, the longer the smoke back-layering length is. With a higher velocity, the smoke tends to move out of the tunnel quickly; however, smoke stratification also occurs, and this reduces visibility. This could make it difficult for people to evacuate. With a higher heat release rate, the smoke tends to move far away from the fires quickly when compared with other cases. Additionally, the higher the heat release is, the longer the smoke back-layering is. Finally, with a higher aspect ratio, the smoke back layering length in the tunnel is also longer. The smoke layer thickness is also larger than in other cases. The correlation of velocity, heat release rate and aspect ratio has been investigated to avoid the smoke back layer length in tunnel fires.

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Numerical Study on Different Series Modes of Jet Fan in a Longitudinal Tunnel Ventilation System

Cited by 11 publications

References 4 publications

Numerical study on the influence of the layout of jet fans on the ventilation effect in tunnel

Numerical study on the influence of the layout of jet fans on the ventilation effect in tunnel

Numerical analysis and control technology of gas accumulation in a large-scale specially-shaped tunnel passing through coal bearing strata

Numerical Study of the Effects of the Jet Fan Speed, Heat Release Rate and Aspect Ratio on Smoke Movement in Tunnel Fires

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