冷却顶板-置换通风空调系统中冷负荷分配比例研究

分别就送风温度、送风速度和顶板供水温度变化等工况进行了不同的模拟实验,对冷却顶板一置换通风复合空调供冷参数提出了建议取值范围。同时,根据实际测试数据加以分析研究,确定了冷却顶板系统和置换通风系统两者所承担的合理供冷份额。     

蒸发式冷凝器在地下工程中的应用

分析当前地下工程通风空凋系统中的大余热问题,将几种向工程外部排热的技术和研究方向进行比较,对设置地下水库的工程提出一种使用蒸发式冷凝器制冷机组进行改进的方法。介绍蒸发式冷凝器的结构、工作原理及其节水、节电、占地面积小的优点,总结目前蒸发式冷凝器在国内应用不广的原因,给出蒸发式冷凝器在地下工程实际应用的设置方案。     

A two dimensional thermal network model for a photovoltaic solar wall

A two dimensional thermal network model is proposed to predict the temperature distribution for a section of photovoltaic solar wall installed in an outdoor room laboratory in Concordia University, Montréal, Canada. The photovoltaic solar wall is constructed with a pair of glass coated photovoltaic modules and a polystyrene filled plywood board as back panel. The active solar ventilation through a photovoltaic solar wall is achieved with an exhaust fan fixed in the outdoor room laboratory. The steady state thermal network nodal equations are developed for conjugate heat exchange and heat transport for a section of a photovoltaic solar wall. The matrix solution procedure is adopted for formulation of conductance and heat source matrices for obtaining numerical solution of one dimensional heat conduction and heat transport equations by performing two dimensional thermal network analyses. The temperature distribution is predicted by the model with measurement data obtained from the section of a photovoltaic solar wall. The effect of conduction heat flow and multi-node radiation heat exchange between composite surfaces is useful for predicting a ventilation rate through a solar ventilation system.     

Numerical analysis of effect of shape-stabilized phase change material plates in a building combined with night ventilation

Effect of shape-stabilized phase change material (SSPCM) plates combined with night ventilation in summer is investigated numerically. A building in Beijing without active air-conditioning is considered for analysis, which includes SSPCM plates as inner linings of walls and the ceiling. Unsteady simulation is performed using a verified enthalpy model, with time period covering the summer season. Effects of the following factors on room air temperature are investigated: the thermophysical properties of the SSPCM, the thickness of SSPCM plate and air change per hour (ACH) at both nighttime and daytime. The results show that the SSPCM plates could decrease the daily maximum temperature by up to 2 °C due to the cool storage at night. The appropriate values for melting temperature, heat of fusion, thermal conductivity and thickness of SSPCM plates need to be considered and calculated according to the climate conditions and building structure. The ACH at night needs to be as high as possible but the ACH at daytime should be controlled.     

某钨矿通风优化方案研究

针对某钨矿山原通风系统的现状,通过网络优化,采取相应的技术措施,使矿山由于开采范围的变化、开采深度的延伸、开采作业地点的改变及工作面的推移等产生的通风问题得以有效解决,改善了矿山作业点的作业环境,对相似矿山具有指导意义。     

中国金属矿山深井通风技术研究现状综述

中国金属矿山深井通风技术研究始于20世纪80年代,现已有近40多个（包括煤矿）矿井井下气温达到或超过30cC,开采深度600～1200m。详述了中国金属矿山深井通风降温现状,介绍了深井通风主要技术;研究国外有关深井开采资料表明,中国金属矿山目前的开采深度,采用普通通风降温技术是可行的。     

湖南宝山有色金属矿业有限责任公司矿井通风系统优化

湖南宝山有色金属矿业有限责任公司矿井深部开采通风困难,通过对通风系统的优化治理,取得了良好效果。文章介绍了其通风系统存在的问题、原因以及通风系统优化治理措施,可供类似矿山参考借鉴。     

Interaction between the mixing and displacement modes in a naturally ventilated enclosure

Experiments are carried out to study for the first time interactive phenomena in buoyancy-induced natural ventilation in a full-scale enclosure with upper and lower openings on one of the sidewalls. The interaction between the mixing and the displacement ventilation modes is revealed by opening the lower vent to different heights while the upper vent is kept fully open. Both the transient process and steady state interaction are explored. Measurements include temperature differences between inside and outside and air velocity through the upper opening. The level of the neutral plane at the upper vent, defined here as the plane separating between inflow and outflow, decreases with R^*$R^{*}$, the ratio between the opening heights (and areas) of the lower and upper vents. Experiments show that when 0*<0.27$0<R^{*}<0.27$ the mixing and displacement modes interact through a new combined ventilation mode. For 0.53*?1$0.53<R^{*}?1$, the displacement mode dominates whereas in the intermediate range, 0.27?R^*?0.53$0.27?R^{*}?0.53$, either the combined or the pure displacement mode takes place. The experiments are in qualitative agreement with a previous theoretical model.     

Numerical investigation of airflow pattern and particulate matter transport in naturally ventilated multi-room buildings

This study reports on a numerical investigation of transport behavior of indoor airflow and size-dependent particulate matter (PM) in multi-room buildings. An indoor size-dependent PM transport approach, combining the Eulerian large-eddy simulation of turbulent flow with the Lagrangian particle trajectory tracking, was developed to investigate indoor airflow pattern and PM1/PM2.5/PM10 removal efficiency in naturally ventilated multi-room buildings. A displacement ventilation with a measured indoor PM10 profile in Taipei Metropolis as the initial condition was carried out to characterize spatial and temporal variations of indoor PM1/PM2.5/PM10 removal behavior. The effects of indoor airflow pattern on particle transport mechanisms, e.g., deposition, suspension, migration and escape, were analyzed. Two comparison scenarios, which considered the effects of no indoor partition and different air change rate, respectively, were also conducted. In comparison with the effectiveness of PM1/PM2.5/PM10 removal, the simulated results showed that coarse particles were easier to be removed out of the building than fine particles. Natural ventilation was not an effective way to remove fine particles such as PM1 and PM2.5 in a multi-room building. Indoor partitions can impede 12% of the mean streamwise velocities and significantly increase 30-50% turbulence intensities. However, indoor partitions increased particle deposition and decreased particle escape. As a result of the two opposite particle removal mechanisms, i.e., deposition and escape, the impact of indoor partitions on PM1/PM2.5/PM10 removal behavior was not as significant as the results of airflow velocities. PRACTICAL IMPLICATIONS: This work developed a computational fluid dynamics technique to investigate indoor airflow patterns and PM1/PM2.5/PM10 removal ability in ventilated multi-room buildings. The results of this paper can help to identify adequate PM1/PM2.5/PM10 cleaning procedure and provide useful size-dependent PM control strategy in multi-room buildings.     

用梯度法解算矿井通风网络

通过修正Scott—Hinsleym风嘲解算方法的缺陷．提出了一种新的全回路调节方法。该方法通过使所有独立回路分支风压代数和的平方和最小化的方法,建立了通风网络解算优化模型,并用梯度法对该模型进行解算,获得了一种新的风网解算算法。该方法理论上考虑到了通风网络中存在固定风量分支的情况,可实现所有回路的调节,并可实现按需分配归零误差。