辐射供冷系统末端形式对比及发展研究

介绍几种辐射供冷空调的末端形式,比较冷吊顶、楼板辐射供冷、毛细管席的供冷能力、热舒适性、能耗及投资等方面的不同,并建议完善辐射供冷系统试验研究方法,着重进行拥有自主产权产品的制造工艺的研究。     

基于辐射供冷的太阳能吸收式空调试验研究

对基于辐射供冷的太阳能吸收式空调系统进行了试验。该系统采用96 m2的U型管式真空管太阳能集热器驱动额定制冷量为8 kW的吸收式制冷机组,吸收式制冷机产生的冷冻水被输送到辐射吊顶中,为50 m2的实验室提供夏季空调。吸收式制冷机运行在夏季晴朗天气时,平均制冷量为4.5 kW。辅助独立除湿机组与辐射吊顶联合运行。试验房间的热舒适指标PMV为-0.29~0.32,可满足热舒适要求。     

舒适,节能的冷却吊顶空调系统

冷却吊顶作为一项节能新技术，深沉与置换通风系统相结合使用，使空调系统更加合理完善，在这种空高系统中，冷却吊顶承担了大部分冷却负荷，而通系统只需处理少量新风以满足卫生所需，国外的大量实践表明，同传统空调系统相比，冷却吊顶系统大大改进了室内空气品质，节约了能耗，提高了系统的经济性，本文介绍了冷却吊顶的运行机理，并分析了其优越性。     

上海期货大厦变风量空调系统实际运行状况的初步分析

对上海期货大厦内变风量空调系统的实际运行状况,如室内空气品质,新风供给,吊顶回风、能耗等方面问题进行了初步分析。以期对今后VAV空调系统的应用有所借鉴。     

地板下空调送风技术概述

地板下空调送风技术作为一项新的空调系统设计手段,利用架空地板下部空间输送空调气体,已广泛应用于高档办公楼。由于地板下送风空调系统相对于天花吊顶上送风空调系统具有节能、洁净、舒适等优点,所以该技术在北美地区迅速发展。地板下空调送风示意图见图1。自从1995年起,美国     

热湿地区直膨式辐射顶板空调系统模拟分析

以广州地区某办公楼为例,利用Energyplus对直膨式辐射顶板空调系统进行模拟,并与风机盘管+独立新风空调系统、双冷源新风机组+辐射顶板空调系统进行能耗对比分析。结果显示,在直膨式辐射顶板空调系统中,辐射顶板承担系统69.2%的显热负荷;相对于风机盘管+独立新风空调系统,系统节能率为20.09%,相对于双冷源新风机组+辐射顶板系统,系统节能率为7.16%。     

能源信息

超深层蓄热井辐射空调系统 日本机械设备建设公司现正着手开发利用超深层蓄热井的辐射空调系统。 空调系统是以PMV值(预设的温度、湿度、气流量及人体辐射热量、着衣程度和运动量等)为参数设计的。将辐射空调系统与100米左右深的超深层蓄热井相结合,可组成一种高效率低能耗的空调系统。     

小型太阳能吸收式空调的运行特性和室内热舒适性试验

在夏季典型工况下,对一个小型太阳能吸收式空调系统进行了试验研究.试验系统主要包括:96 m2的真空管集热器、额定制冷量为8 kW的吸收式制冷机、容量为3t的热水储水箱、500 L蓄冷水箱以及50 m2冷辐射吊顶.试验结果显示吸收式制冷机的制冷量平均为3.9 kW,每天达到的平均制冷时间为10 h.分析了室内的热舒适情况...     

不同供热形式末端性能研究

对北京某高校办公室进行模拟研究,当采用地板辐射、散热器以及毛细管网吊顶辐射3种不同形式的供热末端时,分别研究室内温度的垂直分布以及水平分布,并结合实际工程对3种不同形式末端的经济性进行分析,从室内温度分布和经济性等方面对3种不同形式末端进行对比研究。     

吊顶辐射冷却塔供冷系统试验研究与性能分析

通过供冷试验及TRNSYS软件模拟研究了吊顶辐射冷却塔供冷系统的运行效果,分析了气象参数、部件结构等因素对系统供冷效果的影响,并与常规供冷系统全年的运行能耗进行对比。试验与理论分析结果表明,吊顶辐射冷却塔供冷系统的有效供冷量能够满足用户供冷需要,供冷房间温度稳定且分布均匀。冷却塔供冷效果与大气湿球温度、建筑内部负荷、热交换器结构等因素有关。辐射顶板末端与冷却塔供冷匹配性高,系统全年运行时数增加,应用于需全年供冷的建筑节能效果显著。     

辐射顶板空调系统的优势

本文介绍了辐射顶板空调系统的工作原理，分析亍它具有节能和创造舒适环境的优点。并提出了辐射顶板空调在冬季采暖时的可行性及存在的问题。在大力倡导节能和环保的今天，辐射顶板空调系统作为一种节能、环保的新型空调系统必将拥有广阔的应用前景。     

Numerical analysis of temperature non-uniformity and cooling capacity for capillary ceiling radiant cooling panel

Capillary ceiling radiant cooling panel is a high temperature cooling system, which could pose low energy consumption to meet thermal comfort requirements. A computational fluid dynamics (CFD) simulation study on heat transfer of chilled water flow in the capillary of ceiling radiant cooling panel was performed to attain surface temperature distributions and cooling capacities. Six influencing factors included chilled water inlet parameters, conditions of gypsum plaster and capillary mats structural parameters were considered to obtain the complicated relationships between capillary radiant panel conditions and heat transfer performance. The index of temperature non-uniformity coefficient was proposed to evaluate temperature profiles of ceiling panel surface. The results of the simulation were compared with the values depicted in ASHRAE Handbook and good agreement had been achieved. The average difference between simulation results and the values reported by ASHRAE handbook was within the region of 15%. The research results showed that temperature non-uniformity coefficient was negatively correlated with temperature of chilled inlet water (linear correlation), water velocity (correlation coefficient R = −0.85), and pipe diameter (correlation coefficient R = −0.93), but positively and linearly correlated with tube spacing. Cooling capacity was found to have negative linear correlation with temperature of chilled inlet water, covering thickness and tube spacing.     

Ceiling radiant cooling panel capacity enhanced by mixed convection in mechanically ventilated spaces

The main thrust of this research is to estimate the impact of the mixed convection effect on the cooling capacity of a ceiling radiant panel in mechanically ventilated spaces. To estimate panel cooling capacity enhancement caused by mixed convection, a verified analytical panel model was used. The simplified correlation for mixed convection heat transfer coefficient which can be easily adopted in panel cooling capacity estimation was derived from established mixed convection and natural convection correlations. It was found that the total cooling capacity of radiant panels can be enhanced in mixed convection situations by 5–35% under normal operating panel surface temperatures.     

溶液除湿的地源热泵毛细管顶板空调系统

提出了一种基于溶液除湿的地源热泵毛细管顶板复合空调系统。该系统采用了溶液除湿承担潜热负荷,地源热泵制取的高温冷水承担显热负荷的方式,达到了节省高品位电能、减轻大气污染、减少运行费用的效果,与传统的空调系统相比具有节能、环保、高舒适性的特点。     

Experimental performance of a thermoelectric ceiling cooling panel

An experiment has been performed to investigate the cooling performance of a thermoelectric ceiling cooling panel (TE‐CCP). The TE‐CCP was composed of 36 TE modules. The cold side of the TE modules was fixed to an aluminum ceiling panel to cool a test chamber of 4.5 m³ volume, while a copper heat exchanger with circulating cooling water at the hot side of the TE modules was used for heat release. Tests were conducted using various system parameters. It was found that the cooling performance of the system depended on the electrical supply, cooling water temperature and flow rate through the heat exchanger. A suitable condition occurred at 1.5 A of current flow with a corresponding cooling capacity of 289.4 W which gives the coefficient of performance (COP) of 0.75 with an average indoor temperature of 27°C. Using thermal comfort test data in literature for small air movements under radiant cooling ceilings, results from the experiments show that thermal comfort could be obtained with the TE‐CCP system. Copyright © 2007 John Wiley & Sons, Ltd.     

Passive solar radiant system,SIRASOL. Physical–mathematical modeling and sensitivity analysis

When using passive solar heating systems, it is necessary to have available an Equator-facing facade on which to install them. Rooms without such a facade are not the best option for conventional passive solar heating systems. SIRASOL is a passive solar radiant system that captures solar energy and is to be installed in the ceiling of the room. This room must not necessarily have an Equator-facing facade. Solar energy heats up a metal sheet, which is the radiant panel, which transfers heat by long-wave radiation to the room below it. This paper presents a mathematical model and a sensitivity analysis. The mathematical model was used to analyze radiant panel temperature, radiant mean temperature, operative temperature and panel surface area. Results of the sensitivity study showed that when solar radiation rises (from 200 to 800 W) panel temperature increases from 36 °C to 92 °C, whereas variations in outside and inside air temperature have a negligible impact on the panel temperature. Thus, the use of SIRASOL is possible in locations with clear skies. Moreover, from panel temperature values we calculated mean radiant temperature and thereby the room’s operative temperature, which is proportional to the radiant panel area. When this area is 50% of the room’s floor area, operative temperature grows 3.1 °C higher than inside air temperature when solar radiation is 500 W/m². The analysis shows that a thermal asymmetry appears only when SIRASOL’s surface area to floor area ratio is higher than 32%.     

Radiant ceiling systems coupled to its environment part 1: Experimental analysis

This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The main objective of this study is to present the results of the experimental analysis and measurement methods and its discussion. Two test chambers are adapted in a way to reproduce as good as possible the characteristics of the real offices located in Brussels (Belgium). Forty-six tests are performed to observe the influence of parameters such as the mass flow rate, supply water temperature, fenestration and ventilation system effects and thermal load distribution. Laboratory test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Therefore, the system must be evaluated together with its designed environment and not as separate HVAC equipment.     

红外辐射材料的研究及其在武钢工业炉上的应用

从高温工业炉强化炉内辐射传热过程的角度出发,分析了工业炉应用红外辐射材料的重要意义。在红外辐射材料的研究、涂料节能机理的研究和实际应用技术的研究等方面,系统地介绍了武钢的研究和实际应用情况。根据武钢20多年的实际应用经验,针对不同工业炉具体的工况条件,合理选择性能优良的红外辐射涂料,能够取得良好的节能、增产和延长炉子使用寿命的效果。