煤矿通风系统及风量优化分析

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.     

关于一次风管含尘气流风量测试的探讨

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。     

空调风管系统漏风量测试工程

按照《通风管道技术规程》中规定的对漏风量测试的步骤,对其在实际工程中进行了具体的应用。文中结合漏风量测量的基本原理与工程实践,提供了实际工程中的测试数据和可供参考的建议。     

水泵系统电能平衡测试探讨

<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。     

应用热量计进行供热系统平衡测试

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。     

风道系统单位风量的耗功率分析

风道系统单位风量的耗功率W_s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。     

矿井通风系统风流参数动态监测与风量调节优化

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...     

供热系统水力失调和水力平衡的分析

介绍了水力失调、水力平衡的概念和分类,以及常用的水力平衡方法;分析了供热系统水力失调原因;提出解决水力失调的两种途径：即＂附加阻力平衡＂和＂附加压头平衡＂;分析＂附加压头平衡＂技术的特点和应用的条件。     

供热系统水力失调原因及对策

分析供热系统水力失调的原因和选用大容量设备解决水力失调的不利后果,提出了解决水力失调两种方法.     

山东农业大学水平衡测试及节水分析

单位水平衡测试是指在一个确定的用水单元内,输入水量和输出水量之间遵守物质守恒定律,各种水量之间存在平衡关系。通过对山东农业大学进行水平衡测试,熟悉水平衡测试工作的内容、过程和方法等,摸清学校用水现状,挖掘节水潜力,提出进一步的节水措施和建议。     

某地铁项目空调送风道结构优化

在某地铁项目空调送风道方案设计完成的前提下,利用Catia三维软件进行M车空调送风道建模,然后,利用计算流体模拟软件Fluent对空调送风道进行CFD仿真分析,从而可以得出气流在风道、格栅和客室内部的流动状况。通过统计送风格栅各段的送风量,分析风道送风均匀性,从而最终确定最合理的送风道结构形式,以此改善此项目空调送风均匀及温度均匀性,提高客室空调整体舒适性。     

Experimental study of premixed syngas/air flame deflagration in a closed duct

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.     

以太阳能/空气为热源的直膨式热泵热水系统

介绍了一种直膨式太阳能热泵空调及热水系统。针对春季供热水工况，分别对以太阳能及空气为热源生产生活热水进行了比较，发现以太阳能为热源具有更高的COP值，节能效果更为显著；根据试验数据分析了压缩机工作频率、太阳辐射强度、环境温度等因素对热泵系统性能系数的影响。     

Experimental and numerical study on premixed hydrogen/air flame propagation in a horizontal rectangular closed duct

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.     

Experimental study and three-dimensional simulation of premixed hydrogen/air flame propagation in a closed duct

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.     

IC反应器水力特性实验研究

利用模拟实验的方法，从水力学的角度对压力、沼气产率以及温度与反应器内循环水流量的关系进行了实验研究。研究表明，压力变化是影响内循环水流量的最主要因素；反应器产气率对循环水流量的作用也非常显著，而且在一定范围内，反应器的循环水流量随产气率成线性关系变化；温度对反应器循环水流量的影响相对比较复杂，且与产气速率有很大关系；摩擦力对内循环水流量存在一定程度的影响，在反应器设计过程中不能忽略该因素。     

大空间两种气流组织夏季热环境及其能耗实验研究

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.     

玫瑰花热风干燥实验及模型研究

鲜花干燥后易于保存,有多种用途。研究得出玫瑰花干燥模型以预测干燥过程,指导生产。基于热风温度、风速等做6组试验,得出玫瑰花干燥曲线,研究不同温度、风速对玫瑰花热风干燥特性的影响,并利用Origin等软件对玫瑰花热风干燥数据进行拟合,进行线性分析及可靠性分析,找出最适合描述其干燥过程的薄层干燥模型。结果表明,Logarithmic方程较适合用来描述玫瑰花干燥过程。     

Experimental investigations on heat transfer and frictional characteristics of a turbulator roughened solar air heater duct

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/D_h = 0.0186 to 0.03986 (D_h = 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.