共查询到20条相似文献,搜索用时 146 毫秒
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用数值模拟方法,对北京某城市商业综合体内部公共空间空调工况热环境进行了研究,分析了各层不同送风比例下,综合体内部公共空间纵截面温度分布情况和人员活动区域内的温度分布情况。通过比较,确定了满足综合体内部公共空间各层热舒适要求的空调送风方案。数值模拟结果表明,对于城市商业综合体内部公共空间采用各层均匀送风,顶层与公共空间相连的走廊区域温度在夏季不能满足热舒适要求,适当减少内部公共空间下层的送回风量,增加至顶层,在冬夏工况下均可有效改善内部公共空间热环境,增加舒适度,有效解决顶层走廊温度偏高及温度不均等问题。 相似文献
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结合高温高湿地区的气候特点,设计一种新型的太阳能溶液除湿空调系统,并通过CFD模拟软件Airpak对采用太阳能溶液除湿空调系统的室内舒适性进行模拟分析。模拟主要是在稳态的情况下采用对比分析的方法对同一房间分别采用太阳能溶液除湿辐射空调系统和传统一次回风空调系统进行模拟,对比分析使用这2种空调系统的室内热舒适环境,主要包括室内温度、湿度和风速。结果表明:模拟房间1人体活动区域内温度基本保持在约26℃,相对湿度在55%~60%之间,风速在0.05~0.15 m/s之间,温度和相对湿度分布较为均匀,无吹风感,热舒适性较强;而模拟房间2人体活动区域内温度基本保持在约24℃,相对湿度在40%~80%之间,风速在0.3~0.5 m/s之间,温度和相对湿度分布的均匀性较差,有吹风感,热舒适性较差。设计的太阳能溶液除湿空调系统的室内温度、湿度及速度均分布均匀、波动小且都在相应的舒适区内,室内速度场及室内热湿环境比传统空调系统优越,克服了传统溶液除湿空调系统在热湿地区的应用限制,且可充分利用热湿地区丰富的太阳能等可再生能源,并为高温高湿地区空调系统的节能改造提供一种有益参考。 相似文献
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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. 相似文献
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A parametric analysis on the effect of using a ceiling fan in an air-conditioned room is performed by two-dimensional (2D) numerical simulation of steady state airflow and heat transfer. Thermal comfort analysis is done for a person standing in a room with an inlet and an outlet for air conditioning and a ceiling fan. Representative three-dimensional (3D) simulation is also performed for the comparison of results obtained by using 2D and 3D models. Distributions of velocity, temperature, and relative humidity are presented. Different cases in which the ceilings fan may be not in use or in use with different air speed normal to the plane of fan blades due to different rotational speeds are considered. Predicted mean vote is computed and used to assess the thermal comfort characteristics. It is found that as the normal air speed from the fan increases, thermal comfort significantly shifts toward the cooler scale to allow higher supply air temperature or higher heat load in the room while maintaining the same comfort level. 相似文献
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目前有关超市的室内设计温、湿度对环境舒适性影响的研究匮乏,对超市空调和制冷的相互作用往往忽视或误解。在综合分析了超市室内温度、相对湿度对超市环境舒适性、超市空调能耗、陈列柜能耗的影响后,找出了超市夏季空调最佳温、湿度设定点。 相似文献
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The thermal comfort control of a room must consider not only the thermal comfort level but also energy saving. This paper proposes an enthalpy estimation that is conducive for thermal comfort control and energy saving. The least enthalpy estimator (LEE) combines the concept of human thermal comfort with the theory of enthalpy to predict the load for a suitable setting pair in order to maintain more precisely the thermal comfort level and save energy in the air conditioning system. 相似文献
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Terminal boxes maintain room temperature by modulating supply air temperature and airflow in building heating, ventilation and air‐conditioning (HVAC) systems. Terminal boxes with conventional control sequences often supply inadequate airflow to a conditioned space, resulting in occupant discomfort, or provide excessive airflow that wastes significant reheat energy. In this study, the procedure for the optimal minimum airflow setpoint was developed to improve thermal comfort and reduce energy consumption. The determined minimum airflow setpoint was applied in an office building air‐conditioning system. Improvements in indoor thermal comfort and energy reduction were verified through measurement. The results show that the minimum airflow reset can stably maintain room temperature, satisfy comfort standards and reduce energy consumption compared with the conventional control. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Indoor thermal environment is important as it affects the health and productivity of building occupants. Direct expansion (DX) air conditioning (A/C) units are commonly used for environmental control in small- to medium-scaled buildings. This paper reports on an experimental study to investigate the indoor thermal comfort characteristics under the control of a DX A/C unit having variable-speed compressor and supply fan at a fixed space cooling load but having three different ratios between its sensible part and latent part. The experimental results suggested that under a fixed indoor total cooling load with three different space sensible heat ratios (SHRs) of 0.92, 0.72 and 0.62, varying both speeds of compressor and supply fan in the DX A/C unit would influence indoor thermal comfort. Furthermore, when a DX A/C unit having variable-speed compressor and supply fan is used for indoor thermal comfort control under abnormal indoor load conditions, its ability of indoor thermal comfort control through varying compressor speed and supply fan speed may be duly restricted. 相似文献
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《Energy Conversion and Management》2005,46(15-16):2553-2565
The primary purpose of a heating, ventilating and air conditioning (HVAC) system within a building is to make occupants comfortable. Without real time determination of human thermal comfort, it is not feasible for the HVAC system to yield controlled conditions of the air for human comfort all the time. This paper presents a practical approach to determine human thermal comfort quantitatively via neural computing. The neural network model allows real time determination of the thermal comfort index, where it is not practical to compute the conventional predicted mean vote (PMV) index itself in real time. The feed forward neural network model is proposed as an explicit function of the relation of the PMV index to accessible variables, i.e. the air temperature, wet bulb temperature, globe temperature, air velocity, clothing insulation and human activity. An experiment in an air conditioned office room was done to demonstrate the effectiveness of the proposed methodology. The results show good agreement between the thermal comfort index calculated from the neural network model in real time and those calculated from the conventional PMV model. 相似文献
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随着建筑节能的推广和人们对室内生活舒适性要求的提高,采用一种更先进、更节能的室内空气调节系统就显得日趋重要。毛细管型辐射供暖与供冷系统因具有舒适度高、节能效果显著、节省建筑空间等的优点逐渐被广泛采用。对以毛细管为末端的毛细管型辐射供暖与供冷系统布置形式作了介绍,分析了该系统的组成及优点。以辐射供冷为例,探讨了辐射冷系统的末端一毛细管席供冷量的影响因素。 相似文献
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M. Ilyas 《Energy Conversion and Management》1982,22(3):227-230
The level of thermal cooling in tropical air conditioning is generally kept rather low for the local acclimatized populations. Also it is shown that the effective temperature (ET) comfort index strongly depends upon humidity and should be utilized in regulating the automated air conditioning systems. These considerations together with a site selection on the basis of ET surveys may lead to considerable energy savings. The use of higher ET as basis of tropical cooling would also lead to a physiologically more-comfortable thermal environment. 相似文献
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《热科学学报(英文版)》2019,(6)
The Yangtze River Basin in China is characterised by hot-and cold-humid climates in summer and winter, respectively. Thus, increased demand for heating and cooling energy according to the season, as well as poor indoor thermal comfort, are inevitable. To overcome this problem, this study focused on the influence of passive design and heating, ventilation, and air conditioning equipment performance on the energy performance of residential buildings, and explored potential energy-saving technology paths involving passive design and improved coefficient of performance through a multi-objective and multi-parameter optimisation technique. A large-scale questionnaire survey covering a typical city was first conducted to identify family lifestyle patterns regarding time spent at home, family type, air conditioner use habits, indoor thermal comfort, etc. Then, the actual heating and cooling energy consumption and information of model building were determined for this region. Subsequently, the design parameters of an individual building were simulated using Energyplus to investigate the cooling and heating energy consumption for a typical residential building with an air conditioner. The results indicated an improvement of approximately 30% in energy efficiency through optimisation of the external-wall insulation thickness and the external-window and shading performance, and through use of appropriate ventilation technology. Thus, a multi-objective and multi-parameter optimisation model was developed to achieve comprehensive optimisation of several design parameters. Experimental results showed that comprehensive optimisation could not only reduce cooling and heating energy consumption, but also improve the thermal comfort level achieved with a non-artificial cooling and heating source. Finally, three energy-saving technology paths were formulated to achieve a balance between indoor thermal comfort improvement and the target energy efficiency(20 kWh/(m2?a)). The findings of this study have implications for the future design of buildings in the Yangtze River Basin, and for modification of existing buildings for improved energy efficiency. 相似文献