Energy consumption analysis on a dedicated outdoor air system with rotary desiccant wheel

A dedicated outdoor air system (DOAS) with rotary desiccant wheel is the combination of a desiccant dehumidification system and a vapor compression refrigeration system. An energy consumption model of this hybrid DOAS is established for its analysis. Coefficient of performance, COP, is appropriately defined for evaluation on performance of the hybrid DOAS. The results indicate that, compared with a conventional DOAS, energy savings are possible for the suggested DOAS, when solar energy or natural gas is used for regeneration. Ventilation air flow rate, temperature or humidity of outdoor air, as well as regeneration-to-process air ratio, influence the energy consumption and the COP of the hybrid DOAS, greatly.     

谈北京公馆的节能技术设计

北京公馆作为高档公寓,在设计中采用了钢结构、呼吸式玻璃幕墙、水源热泵系统、地板采暖系统、独立新风系统等多种节能措施。多种节能措施的综合运用,在建筑工程的可持续发展方面具有一定的探索意义。     

室外给水塑料管网的创新设计研究

从消防设计、管网平面布置及安装的角度入手,将室外给水管网进行了分类,重点就室外给水塑料管网的设计要点进行了研究,以积累相关设计经验,确保给水管网的正常运行。     

地板辐射供冷系统的热性能研究

实验比较了双位开关控制、变流量控制和室外温度补偿+室温反馈控制方式下地板辐射供冷系统室内温度稳定性、地板表面温度稳定性以及结露发生频率.研究结果表明,室外温度补偿控制方式的最低供水温度为15℃,室外温度补偿率为0.25;在运行初期,双位开关控制室温稳定性优于其他控制方式,随着系统运行时间延长,室外温度补偿+室温反馈控制...     

Thermal conditioning for urban outdoor spaces through the use of evaporative wind towers

The aim of this paper is to study the thermal comfort levels achieved in open spaces by means of evaporative wind towers. These systems have been installed in an urban area characterized by its hot and dry summer climate. Conventional wind tower designs for enclosed and semi-enclosed spaces have been adapted for this new installation. These systems are usually composed of a few number of wind towers, this one however is composed by a group of sixteen, increasing the total dimensions of the installation. To integrate this construction into the urban public area, it was built in a circular arrangement, creating an activity and meeting point for pedestrians. This passive system was monitored during the summer of 2008. Measurements of temperature, solar radiation, humidity and wind speed were analyzed. During the analyzed period, the average cooling efficiency of the system varied from 38% at the exit of the tower, to 32% at 1 m high. At this last position, the average exceeds the wet bulb temperature up to 8 °C with an increase of moisture around 27%. The shading effect produced by the global installation itself has been modeled theoretically to evaluate the incident solar radiation at the pedestrian area. Two indices have been applied to predict the perception of heat and cold in the south pedestrian zone: Heat index and TS index. In this position, both variables approached the thermal sensation to the comfort levels by the use of these passive strategies when ambient conditions are hot and dry.     

居住区老年人户外活动及其空间特征研究——夏季户外活动实态调查

以北京市近年来新建的居住小区为例,对夏季老年人户外活动的类型、时间规律、活动空间的特征进行了调查分析与规律总结,在此基础上提出夏季居住区老年人户外活动空间设计的建议。     

The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area

In this study, elemental composition of PM2.5 and the status of indoor/outdoor pollution were investigated in a commercial building near a roadside area in Daejeon, Korea. A total of 60 parallel PM2.5 samples were collected both on the roof (outdoor) and in an indoor office of a building near a highly congested road during the spring and fall of 2008. The concentrations of 23 elements were analysed from these PM2.5 samples using instrumental neutron activation analysis. PM2.5 levels in indoor environment (47.6 ± 16.5 μg/m(3)) were noticeably higher than the outdoor levels (37.7 ± 17.2 μg/m(3)) with the I/O concentration ratio of 1.37 ± 0.33 [correlation coefficient (r) = 0.89, P < 0.001]. Principal component analysis results coincidently showed the predominance of sources such as soil dust, traffic, oil/coal combustion and road dust for both indoor and outdoor microenvironments. An isolated source in the indoor environment was assigned to environmental tobacco smoke (ETS) with high factor loading of Ce, Cl, I, K, La and Zn. The overall results of our study indicate that the sources of indoor constituents were strongly dependent on outdoor processes except for the ones affected by independent sources such as ETS. PRACTICAL IMPLICATIONS: An improved understanding of the factors affecting the indoor PM2.5 concentration levels can lead to the development of an efficient management strategy to control health risks from exposure to indoor PM2.5 and related toxic components. A comparison of our comprehensive data sets indicated that most indoor PM2.5 and associated elemental species were strongly enriched by indoor source activities along with infiltration of ambient outdoor air for a naturally ventilated building.     

用太阳辐射转化法计算室外照度值

针对中国光气候数据资料不足、太阳辐射数据丰富以及资金有限的现状,在分析多种光气候数据采集方法的基础上,选用太阳辐射转化法获得光气候数据.引入发光功效的概念作为室外照度值和太阳辐射量转化的基本关系,并分析对比了已有的发光功效模型,运用天空晴朗指数,以重庆1991-1992年的实测数据为基础进行拟合,建立了总发光功效模型和...     

基于无线传感器的智能监测输液系统设计

设计了一种用于实时测量患者脉搏、体温、血压和呼吸频率的生命体征监测传感器及其与智能输液装置组成的监控系统;分析了患者在输液过程中实行生命体征智能监控的有效性和安全性,并以电子血压计全自动智能测量的实现为例,阐述血压监测传感器的单片机模块与RF收发芯片的接口设计原理与方法;系统设计中通过短距离无线通信技术实现了患者输液过程中的各项生命体征智能监控,实现了患者治疗过程中医护人员无须值守及护士因多点护理带来的问题;有利于网络在线监测、系统安全性警示与应急救护相结合的综合治疗与管理。