北方地区办公建筑夜间通风适用性分析

根据我国北方严寒和寒冷地区167个气象台站典型气象年气象数据,定量分析夜间通风降温技术在我国北方严寒和寒冷地区的气候适宜性,以"气候降温潜力"作为指标量化分析夜间通风的适用性,得出各台站夜间通风气候降温潜力值,并结合地理信息系统(GIS)的分析软件给出夜间通风气候降温潜力分布图,将分析结果可视化。     

多级蒸发冷却在化工厂变频器室通风降温的应用

介绍传统变频器室的降温方式以及多级蒸发冷却技术的特点,并以贵州福泉某变频器室为例,进行多级蒸发冷却通风降温设计,通过与传统机械全面通风降温及单元式空调柜机降温方案进行比选,可以得出多级蒸发冷却通风降温系统在节能方面和运行投资方面均具有很大的优势,为该系统在贵州地区的应用提供技术参考.     

矿井通风的类型

矿井通风系统由影响矿井安全生产的主要因素所决定。根据相关因素把矿井通风系统划分为不同类型。根据瓦斯、煤层自燃和高温等影响矿井生产安全的主要因素对矿井通风系统的要求,为了便于管理、设计和检查,把矿井通风系统分为一般型、降温型、防火型、排放瓦斯型、防火及降温型、排放瓦斯及降温型、排放瓦斯及防火型、排放瓦斯与防火及降温型几种,依次为1～88个等级。根据井筒与采区的布置位置分为中央式、对角式和混合式3个类型。     

矿井通风的类型

<正>矿井通风系统由影响矿井安全生产的主要因素所决定。根据相关因素把矿井通风系统划分为不同类型。根据瓦斯、煤层自燃和高温等影响矿井生产安全的主要因素对矿井通风系统的要求,为了便于管理、设计和检查,把矿井通风系统分为一般型、降温型、防火型、排放瓦斯型、防火及降温型、排放瓦斯及降温型、排放瓦斯及防火型、排放瓦斯与防火及降温型几种,依次为1~88个等级。根据井筒与采区的布置位置分为中央式、对     

浅层地热能联合太阳能集热墙系统夏季降温试验研究

针对目前被动式太阳房普遍存在的夏季室内过热现象,提出一种浅层地热能联合太阳能集热墙系统。并在石河子地区对采用该系统的被动式太阳房进行试验测试,对比分析3种通风模式和3种通风时间的降温效果。试验结果表明:采用浅层地热能联合太阳能集热墙系统的通风模式C3的室内平均温湿度明显优于其他模式,平均温度降低了2.64℃;通风时间为12 h的C5模式,其被动降温效果优于其他两种模式,且随着通风时间的延长,被动降温效果出现下降的趋势。     

内燃机车试验车间通风与排烟

介绍发动机出厂试验车间发动机总的发热量，每一部份热量所占比例及热损去向。试验车间通风量的计算，通风降温方案。发动机总的排烟量计算，降低烟气温度所需新风量计算及排风系统降温，防火及防爆措施。     

谈谈普通家庭夏天降温节电的有效措施

1 我国近几年,每年出现连续多天的酷热高温天气,影响着千家万户的日常生活,如何克服夏天酷热,切实降低家庭内环境温度,这是大家关注的话题.上述内容属通风降温、空气调节专业范畴,涉及房屋结构、地区热环境,空调工程与单元技术等条件因素,还有人的生活习惯、年龄、健康等.现实急需降温,目前只能因地制宜,把现有可实施通风降温的器材物资积极的组合使用,力求既降温又节电,减少经济开支.     

通风量对菇渣好氧发酵温度时空特性的影响

采用不同通风量进行菇渣与猪粪高温共发酵,研究通风对发酵过程中堆体温度的时空变化的影响。结果表明,通风使堆体温度呈现出明显的梯度效应,不同处理各发酵时期的温度分布均由剖面中部向四周不断降低。高温区域的位置和面积随发酵时间呈动态变化规律,升温期温度在发酵罐中上部积聚,高温分布区类似椭圆形,高温期椭圆面积逐渐向堆体中部扩散和扩大,随后高温面积不断递减并向中下部迁移,降温期堆体各区域温度趋于一致。由等值线的疏密程度可知,温度的空间变异性大体呈现出高温期>第2次高温期>升温期>降温期的规律。结合试验各阶段的温度变化并考虑节能降耗,得出发酵升温期和高温期分别以0.05,0.067m3/(d·m3)进行通风,二次高温期与降温期以0.033 m3/(d·m3)进行通风条件最佳。     

内燃机试验车间通风与排烟

介绍发动机出厂试验车间发动机总的发热量，每一部份热量所占比例及热损失去向。试验车间通风量的计算、通负降温方案。发动机总的排烟量计算、降低烟气温度所需新风量计算及排风系统降温、防火及防爆措施。     

某油田长输管道高压变频器室通风节能设计方案

为解决某油田长输管道所设高压变频器室现有冷却降温系统能耗高的问题,设计了包裹式通风系统,并对其通风效果进行了仿真模拟,同时对新旧通风系统能耗及工程投资进行了对比,采用包裹式通风系统可使变频器室内温度维持在28~35℃,并且节约电能及投资。     

大型汽轮发电机通风系统研究综述

为满足汽轮发电机不断地向大型化发展地需要，必须对大型汽轮发电机的通风系统进行优化设计，以提高其通风冷却效果。为此，国内外对影响汽轮发电机通风冷却状况的主要因素如冷却介质的流动与传热特性、不同通风系统的通风计算方法、通风系统的结构等进行了一系列理论分析和试验研究，并取得不少具有实际应用价值的成果。在对现有成果的分析和总结的基础上，指出了有待进一步研究之处。     

一种新型永磁磁力耦合器导风散热片的仿真研究

本研究针对一款新型永磁磁力耦合器导风散热装置的导风散热片进行仿真分析。首先设计单因素实验,对其部分几何参数进行研究,利用Fluent软件进行流固耦合模拟,得出几何参数对最高温升及阻力距的影响关系,为正交实验提供合理的参数范围。然后设计正交实验,利用极差分析得出合理的参数组合。最后利用上文参数组合建模,模拟安装不同导风散热片个数的散热效果,寻找合适个数。并与未安装导风散热片的模型进行对比,得出此新型导风散热片设计合理,具有一定的实用价值。     

Cooling-energy reduction in air-conditioned offices by using night ventilation

Night ventilation has been applied successfully to many passively-cooled or low-energy office buildings. This paper investigates the applicability of night ventilation in air-conditioned office buildings. A thermal and ventilation simulation model, together with suitable weather data were used to examine the potential for energy savings and/or improved internal comfort conditions by applying night ventilation cooling. It was found that natural ventilation strategies could save cooling energy in typical air-conditioned offices. However, the use of mechanical ventilation could lead to increased energy-consumption. If typical offices are modified to incorporate features assisting the application of night ventilation, then cooling energy could be saved when mechanical ventilation is used and further reduced in the case of natural ventilation. Such features would include exposed thermal mass or offices designed to ‘best practice’ guidelines, such as airtight construction and minimisation of internal and solar heat gains.     

Integration of variable refrigerant flow and heat pump desiccant systems for the cooling season

Energy saving and indoor air condition enhancing potentials by integrating the variable refrigerant flow (VRF) and heat pump desiccant (HPD) systems were investigated in a field performance test during a cooling season. Three different operating modes: non-ventilated, HPD ventilation assisted and HPD ventilation–dehumidification assisted VRF systems were investigated. The HPD systems operated in the ventilation–dehumidification mode dehumidify the outdoor air and supply it to the indoor air during the ventilation. It was found that the VRF systems provided an average of 97.6% of the total cooling energy for the HPD ventilation assisted mode. The remainder was the recovered cool by the HPD systems during ventilation. The VRF systems provided an average of 78.9% of the total cooling energy for the HPD ventilation–dehumidification assisted mode. The remainder was covered by the HPD systems which provided additional sensible and latent cooling. Overall, among the three operating modes, it is concluded that the HPD ventilation–dehumidification assisted VRF outdoor units consume less energy than the HPD ventilation assisted ones, but more than the non-ventilated ones, while providing the best indoor thermal comfort and indoor air quality conditions. For the total system, the HPD ventilation–dehumidification assisted VRF systems consume less energy than the HPD ventilation assisted ones.     

Cooling load reduction in office buildings of hot-arid climate,combining phase change materials and night purge ventilation

Night purge ventilation is a well-known passive technique for conserving cooling energy by storing night coolth in the thermal mass of the building fabric. We study the effect of phase change materials (PCM) as a light thermal mass, on the cooling load of a typical office building with HVAC system and night purge ventilation in hot-arid climate. In this paper the proper conditions to start night ventilation and the ventilation rate by fans is determined. Additionally, the effect of melting point temperature of the PCMs on the cooling load of the building is investigated. PCMs with proper melting temperature were applied to various building elements, and to the whole model. It was revealed that, application of PCMs will significantly contribute in reducing the cooling load, except for the floor on the ground, which resulted in an increase of the load.     

水轮发电机带暖风窗结构通风系统分析

发电机放热风用于电厂厂房采暖是一种经济节能的方法。为了分析增设暖风窗的合理结构及对发电机组通风冷却系统的影响,本文采用网络分析法对发电机组通风冷却系统进行了计算分析。结果表明发电机上加装暖风窗放热风是可行的,对发电机冷却无不利影响。     

高效喷雾通风冷却塔在循环水场中的节能分析

高效喷雾通风冷却塔通过通风蒸发、热传导形式带走热量来完成热水的降温过程,其主要特点是喷流雾化和利用循环水的余能来推动空气在冷却塔内的强制流动,从而代替轴流风机达到节电节能的目的。其核心部件是喷雾推进雾化器,其主轴采用高分子非金属耐磨材料制造,克服了用油轴承在水环境中易锈蚀、卡死等故障,减少了设备维修量。2008,中国石化洛阳分公司采用高效喷雾通风塔冷却技术对第三循环水场3号塔进行了改造,投用至今运行稳定,主要运行参数达到了预期的目的,冷却效果与使用轴流风机相当,循环泵电流与改造前相当,没有增加循环水的回水管路阻力。若洛阳石化循环水冷却塔轴流风机全部进行此技术改造,保守计算年可节电1500×10^4kW·h。     

Passive cooling in a low-energy office building

In office buildings, the use of passive cooling techniques combined with a reduced cooling load may result in a good thermal summer comfort and therefore save cooling energy consumption. This is shown in the low-energy office building ‘SD Worx’ in Kortrijk (Belgium), in which natural night ventilation and an earth-to-air heat exchanger are applied. In winter, the supply air is successively heated by the earth-to-air heat exchanger and the regenerative heat exchanger, which recovers the heat from the exhaust air. In summer, the earth-to-air heat exchanger cools the ventilation air by day. In addition, natural night ventilation cools down the exposed structure which has accumulated the heat of the previous day. In this article the overall thermal comfort in the office building is evaluated by means of measuring and simulation results. Measurements of summer 2002 are discussed and compared to simulations with a coupled thermal and ventilation simulation model TRNSYS-COMIS. The simulations are used to estimate the relative importance of the different techniques. The evaluation shows that passive cooling has an important impact on the thermal summer comfort in the building. Furthermore, natural night ventilation appears to be much more effective than an earth-to-air heat exchanger to improve comfort.     

自然通风高位收水冷却塔性能对比分析

以某逆流式自然通风常规冷却塔为研究对象,对其相同尺寸的高位收水冷却塔进行对比仿真分析,研究布置高位收水装置对冷却塔效果的影响.在多种运行工况下分别对常规冷却塔和高位收水冷却塔进行模拟计算,分析高位收水装置布置前后塔内空气流动和温度变化,以及冷却水平均温降的变化.结果表明,相较于常规冷却塔,同种条件下高位收水塔内通风量增...     

Climatic potential for passive cooling of buildings by night-time ventilation in Europe

Due to an overall trend towards less heating and more cooling demands in buildings in many European countries over the last few decades, passive cooling by night-time ventilation is seen as a promising technique, particularly for commercial buildings in the moderate or cold climates of Central, Eastern and Northern Europe. The basic concept involves cooling the building structure overnight in order to provide a heat sink that is available during the occupancy period. In this study, the potential for passive cooling of buildings by night-time ventilation was evaluated by analysing climatic data, without considering any building-specific parameters. An approach for calculating degree–hours based on a variable building temperature – within a standardized range of thermal comfort – is presented and applied to climatic data of 259 stations all over Europe. The results show a high potential for night-time ventilative cooling over the whole of Northern Europe and still significant potential in Central, Eastern and even some regions of Southern Europe. However, due to the inherent stochastic properties of weather patterns, a series of warmer nights can occur at some locations, where passive cooling by night-time ventilation alone might not be sufficient to guarantee thermal comfort.