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在矿井通风系统运行过程中,巷道风量随着矿井通风网络的变化而变化.为了保证矿井通风的有效性,需要对巷道的风量进行调节.简要介绍了风量分配的基本规律,探讨了风量优化调节的措施,以期为改善矿井通风系统的运行状况提供一定的参考. 相似文献
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就实际工作中遇到的一次风管含尘气流风量问题及如何简便计算 ,提出来供探讨 ,以更好地运用到实际工作中。 相似文献
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<正> 贵刊在1987年第12期研究与探讨栏目刊登了《对水泵电平衡测试的探讨》一文,文中对该厂在电能平衡中对水泵的测试做了一些介绍,我们觉得把水泵测试扩展到水泵系统更为合适,下面就我们在实际工作中的做法作一介绍。 相似文献
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我们应用上海大华仪表厂生产的NRS—01型热水热量指示积算仪(以下简称热量计)在对哈尔滨师范大学供热系统进行测定时,对该型仪表在供热系统中的应用作了系统的研究,提出了正确确定仪表量程的方法,创造了一套仪表的校核和标定方法;同时对该型仪表的误差特点进行了分析,为正确使用该型仪表提出了建议。 相似文献
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风道系统单位风量的耗功率Ws有三个要素组成:沿程阻力、局部阻力和风机效率。本文引入风道单位风量沿程阻力耗功率和单位风量单位局部阻力系数耗功率两个参数,对GB50189-2015的Ws计算式进一步求解,得出更方便的计算式,并利用该式进行分析探讨,在设计中可以快捷地满足节能要求。 相似文献
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以S煤矿为例,在概述其矿井通风系统现状及矿井通风系统改进措施的基础上,从监测系统分站及线缆设置、风流参数传感器及监测点选址、滤波分析等方面进行了该矿井通风系统改进后风流参数动态监测的研究,并对风量调节优化模型的构建思路以及约束条件进行分析探讨.结果表明:矿井通风系统风流参数实时监测、风量调节优化及通风机自动监控是保证矿... 相似文献
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Minggao Yu Xufeng Yang Kai Zheng Ligang Zheng Xiaoping Wen 《International Journal of Hydrogen Energy》2018,43(29):13676-13686
The propagation behaviour of a deflagration premixed syngas/air flame over a wide range of equivalence ratios is investigated experimentally in a closed rectangular duct using a high-speed camera and pressure transducer. The syngas hydrogen volume fraction, φ, ranges from 0.1 to 0.9. The flame propagation parameters such as flame structure, propagation time, velocity and overpressure are obtained from the experiment. The effects of the equivalence ratio and hydrogen fraction on flame propagation behaviour are examined. The results indicate that the hydrogen fraction in a syngas mixture greatly influences the flame propagation behaviour. When φ, the hydrogen fraction, is ≥0.5, the prominently distorted tulip flame can be formed in all equivalence ratios, and the minimum propagation time can be obtained at an equivalence ratio of 2.0. When φ < 0.5, the tulip flame distortion only occurs in a hydrogen fraction of φ = 0.3 with an equivalence ratio of 1.5 and above. The minimum flame propagation time can be acquired at an equivalence ratio of 1.5. The distortion occurs when the maximum flame propagation velocity is larger than 31.27 m s?1. The observable oscillation and stepped rise in the overpressure trajectory indicate that the pressure wave plays an important role in the syngas/air deflagration. The initial tulip distortion time and the plane flame formation time share the same tendency in all equivalence ratios, and the time interval between them is nearly constant, 4.03 ms. This parameter is important for exploring the quantitative theory or models of distorted tulip flames. 相似文献
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Experimental and numerical study on premixed hydrogen/air flame propagation in a horizontal rectangular closed duct 总被引:1,自引:0,他引:1
Huahua Xiao Qingsong WangXuechao He Jinhua SunLiyin Yao 《International Journal of Hydrogen Energy》2010
Hydrogen is a promising energy in the future, and it is desirable to characterize the combustion behavior of its blends with air. The premixed hydrogen/air flame microstructure and propagation in a horizontal rectangular closed duct were recorded using high-speed video and Schlieren device. Numerical simulation was also performed on Fluent CFD code to compare with the experimental result. A tulip flame is formed during the flame propagating, and then the tulip flame formation mechanism was proposed based on the analysis. The induced reverse flow and vortex motion were observed both in experiment and simulation. The interactions among the flame, reverse flow and vortices in the burned gas change the flame shape and ultimately it develops into a tulip flame. During the formation of the tulip flame, the tulip cusp slows down and stops moving after its slightly forward moving, and then, it starts to move backward and keeps on a longer time, after that, it moves forward again. The structure of the tulip flame is becoming less stable with its length decreasing in flame propagation direction. The flame thickness increases gradually which is due to turbulence combustion. 相似文献
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An experimental and numerical study of premixed hydrogen/air flame propagation in a closed duct is presented. High-speed schlieren photography is used in the experiment to record the changes in flame shape and location. The pressure transient during the combustion is measured using a pressure transducer. A dynamic thickened flame model is applied to model the premixed combustion in the numerical simulation. The four stages of the flame dynamics observed in the experiment are well reproduced in the numerical simulation. The oscillations of the flame speed and pressure growth, induced by the pressure wave, indicate that the pressure wave plays an important role in the combustion dynamics. The predicted pressure dynamics in the numerical simulation is also in good agreement with that in the experiment. The close correspondence between the numerical simulation and experiment demonstrate that the TF approach is quite reliable for the study of premixed hydrogen/air flame propagation in the closed duct. It is shown that the flame wrinkling is important for the flame dynamics at the later stages. 相似文献
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以某大空间实验基地为研究对象,针对喷口送风和柱状下送风两种分层空调的热环境及供冷量进行了实测研究.研究结果表明:因喷口送风空调区较大,在夏季室外气象参数基本相同的两种室外气象条件下,喷口送风空调系统供冷量比柱状下送风空调系统的供冷量分别高出20.8%、24.4%,且喷口送风空调系统抗干扰能力较柱状下送风强;喷口送风时工作区温度均匀性好于柱状下送风,头足温差较小,但其工作区风速超过标准,而柱状下送风时工作区风速则符合环境设计要求;两种不同送风量下喷口送风时吹风感指数分别为15.64%、11.23%,而柱状下送风时吹风感指数分别为4.17%、2.40%,柱状下送风要明显优于喷口送风.故从节能及热舒适性角度综合考虑,单侧回风的大空间建筑应尽可能采用柱状下送风分层空调,而对于干扰比较大,空调场地较小,无法布置柱状下送风口的场合,则选取喷口送风较好. 相似文献
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Santosh B. Bopche Madhukar S. Tandale 《International Journal of Heat and Mass Transfer》2009,52(11-12):2834-2848
An experimental investigation has been carried out to study the heat transfer coefficient and friction factor by using artificial roughness in the form of specially prepared inverted U-shaped turbulators on the absorber surface of an air heater duct. The roughened wall is uniformly heated while the remaining three walls are insulated. These boundary conditions correspond closely to those found in solar air heaters.The experiments encompassed the Reynolds number range from 3800 to 18000; ratio of turbulator height to duct hydraulic mean diameter is varied from, e/Dh = 0.0186 to 0.03986 (Dh = 37.63 mm and e = 0.7 to 1.5 mm) and turbulator pitch to height ratio is varied from, p/e = 6.67 to 57.14 (p = 10 to 40 mm). The angle of attack of flow on turbulators, α = 90° kept constant during the whole experimentation. The heat transfer and friction factor data obtained is compared with the data obtained from smooth duct under similar geometrical and flow conditions. As compared to the smooth duct, the turbulator roughened duct enhances the heat transfer and friction factor by 2.82 and 3.72 times, respectively. The correlations have been developed for area averaged Nusselt number and friction factor for turbulator roughened duct. 相似文献