Effect of ventilation and filtration on submicrometer particles in an indoor environment

The effect of filtration and ventilation on reduction of submicrometer particle concentration indoors was investigated in an office building. The air-handling system consisting of dry media filters and an air-conditioning unit, reduced particle concentration levels by 34%. The characteristics of indoor airborne particles were dominated by, and followed the pattern of, outdoor air, with vehicle combustion aerosols as the main pollutant. The ratio indoor/outdoor particle concentration varied between 14 and 26% for different sub-zones. The presence of significant source of particles indoors was not observed. A simple mathematical model predicting evolution of particles indoors is presented. The model, based on a particle number balance equation, was validated with experimental data and showed very good agreement between predicted and measured parameters.     

射流通风增压技术的研究

目前，公路、铁路隧道普遍采用纵向式射流通风，虽然射流通风系统具有很多优点，但射流通风效率较低，一般仅为15％左右．本文采用在射流风机出口设置收缩管以提高射流速度的方法。通过射流增压和隧道通风效率的理论分析及实例计算，表明该方法可使射流增压有显著的提高，最高达到54．8％。从而提高了隧道射流通风的通风效率，大约能提高10个百分点。     

The influence of the zone's indoor temperature settings on the cooling/heating loads for fixed and controlled ventilation

In this study, the thermal performance and the energy requirements of a building single-zone are investigated for both the cooling and heating seasons by employing a thermal-network model. The model has six primary heat-flow paths, in order to take into account the position of insulation in the building envelope, and two secondary paths for the ventilation and the cooling/heating unit. The desired indoor temperature of the zone is defined by a pair of preset points of a thermostat. The energy demands and the resulting indoor temperature variations are determined for fixed ventilation as well as for temperature-controlled ventilation. Computer results for both seasons show how the combined influence of slab structure formations, the desired indoor temperature and ventilation control affect the cooling and heating loads.     

炎热高湿地区火力发电厂配电装置室降温方式探讨

针对炎热高湿地区火力发电厂配电装置室的降温通风方式和空调降温方式的经济技术比较,给出适合于全年室内设备散热量大的房间的降温方式。     

新元公司无煤柱开采充填技术应用与推广

文章介绍了阳煤集团新元公司无煤柱开采技术应用的背景与生产地质条件,通过高水材料巷旁充填沿空留巷技术在高瓦斯突出煤层松软围岩条件下的成功试验,工作面由原来的“U+L”通风方式优化成“Y”型通风方式,目前矿井3号煤所有工作面实现无煤柱开采,高水材料巷旁充填技术在新元公司及阳煤集团得到广泛推广。     

多级机站通风新模式和矿井通风技术的新进展

文中详细论述了我国“九五”期间金属矿山在多级机站通风系统改造中涌现出的先进技术 ,反映了我国矿山通风技术的发展现状。同时 ,探讨了矿井通风技术的发展方向 ,对矿井通风系统的改造研究具有一定意义     

Choosing the Right Parameter for Single-Duct Constant Air Volume System Supply Air Temperature Reset

To improve system efficiency under part-load conditions, the supply air temperature set point for a single-duct constant air volume air handling unit (AHU) system is often reset based on either return air temperature or outside air temperature. Both reset strategies make engineering sense as long as the reset schedules are reasonable. Quite often the decision to use one over the other is made with the assumption that they will both achieve some energy savings. However, the impact of these two strategies on AHU energy consumption could be very different. An in-depth analysis and comparison of these two commonly used supply air temperature reset strategies for a single-duct constant air volume system is presented in this paper. It is shown that the reset strategy based on outside air temperature is inherently better than that based on return air temperature, with lower energy consumption and improved building comfort level.     

Catalytic combustion of coal mine ventilation air methane

Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive mine methane, and approximately 70% of all coal mining related emissions are from underground ventilation air. Hence, research and development on mine methane capture, mitigation and utilisation should focus on methane emitted in ventilation air.To develop more efficient, cost effective technology for the mitigation and utilisation of mine ventilation air methane, this paper introduces the monolith catalyst bed reactor, which has better characteristics for power generation applications than fixed bed and fluidised bed reactors. This is due to its very low pressure drop at elevated mass throughputs, high geometrical area, and high mechanical strength and high resistance to dust. This paper briefly reviews methane catalytic combustion basics, and mainly presents experimental results on simulated ventilation air methane (VAM) catalytic combustion performance of four catalysts tested at different temperature, pressure and CH₄ concentrations. The experimental results show that determination of major operational parameters including temperature is very important for designing large-scale combustors to achieve high methane conversion rate. The major operational parameters determined in the experimental rig would be a reference for the design. In general, a preheated air temperature of ≥450 °C is required for the most effective of the four tested catalysts.     

Indoor air quality,ventilation and health symptoms in schools: an analysis of existing information

We reviewed the literature on Indoor Air Quality (IAQ), ventilation, and building-related health problems in schools and identified commonly reported building-related health symptoms involving schools until 1999. We collected existing data on ventilation rates, carbon dioxide (CO2) concentrations and symptom-relevant indoor air contaminants, and evaluated information on causal relationships between pollutant exposures and health symptoms. Reported ventilation and CO2 data strongly indicate that ventilation is inadequate in many classrooms, possibly leading to health symptoms. Adequate ventilation should be a major focus of design or remediation efforts. Total volatile organic compounds, formaldehyde (HCHO) and microbiological contaminants are reported. Low HCHO concentrations were unlikely to cause acute irritant symptoms (<0.05 ppm), but possibly increased risks for allergen sensitivities, chronic irritation, and cancer. Reported microbiological contaminants included allergens in deposited dust, fungi, and bacteria. Levels of specific allergens were sufficient to cause symptoms in allergic occupants. Measurements of airborne bacteria and airborne and surface fungal spores were reported in schoolrooms. Asthma and 'sick building syndrome' symptoms are commonly reported. The few studies investigating causal relationships between health symptoms and exposures to specific pollutants suggest that such symptoms in schools are related to exposures to volatile organic compounds (VOCs), molds and microbial VOCs, and allergens.     

基于构件的矿井通风安全管理系统的开发研究

本文分析了矿井通风安全管理系统的开发现状、趋势以及开发中存在的问题，对其开发方法和模式进行了探讨，基于．NET技术提出了矿井通风安全管理系统的快速原型法与构件技术相结合的开发模式，较好地解决传统的开发方法存在的问题。