辐射供冷加新风系统适用场所与运行控制策略

在设定条件下,对辐射供冷+新风系统中辐射板表面结露的现象进行了分析。提出以单位质量新风除湿能力作为指标初步判断各种公共建筑是否适用辐射供冷+新风系统。对辐射供冷+新风系统的温湿度独立控制运行原理进行了革新,提出优先控制湿度的运行策略。     

某辐射空调工程设计与应用研究

本文以南京某会所空调系统为例,介绍了顶棚辐射板供冷(暖)和转轮除湿新风机组相结合的空调系统设计方案,顶棚辐射板供冷(暖)系统的特点及安装方式、转轮除湿新风机组、空调冷热源系统及温湿度独立控制系统的设计要点。     

闭式水源热泵与辐射顶板空调系统设计案例分析

杭州某别墅工程空调系统设计,采用湖水源热泵系统+顶板辐射供冷供暖系统+独立新风除湿系统,并设立控制、转换机制,对闭式水源热泵与辐射顶板供冷供热系统的设计方法与对应策略进行简述,既节约工程成本又节能环保。     

高温热泵转轮除湿及辐射供冷空调系统性能研究

本文提出将高温热泵转轮除湿及辐射供冷复合空调系统应用于高温高湿地区,解决辐射顶板表面结露严重的问题。系统将高温热泵转轮除湿的新风空调系统与室内辐射供冷系统结合,高温热泵转轮除湿空调系统提供低含湿量的新风送入房间,承担全部潜热负荷和新风负荷,辐射板承担显热负荷,对系统进行了热力学分析,分析表明系统能达到送风状态点。应用Airpak软件数值模拟研究了送风湿度对顶板结露和人体舒适度的影响。结果表明室内设计状态点温度26℃、相对湿度45%,辐射板下方能形成一层干燥的空气保护层,将辐射板与空间下部高湿气流隔开,房间平均PMV-PPD值分别为0.48/22%,满足人体舒适性要求。     

辐射供冷空调防结露机理及相关技术分析

辐射冷板夏季供冷时的结露问题是目前阻碍这一系统广泛应用的最大障碍,结露是必须重视并应杜绝的现象。本文分析了辐射供冷空调防结露控制机理,探讨了防结露对独立新风系统的要求。总结分析了国内外相关防结露技术,并提出了适宜我国国情的防结露技术。采用提高进水温度、匹配新风除湿系统等合理的基础设计措施是辐射供冷空调防结露工作得以顺利进行的前提,加强系统运行阶段的防结露控制是保障室内环境安全性的有力措施。对于国内常用的混凝土预埋管辐射冷板,由于其冷延迟特性,通过控制新风系统控制室内空气露点温度做为防结露的主要措施更为合理。     

采用常规冷水机组作为冷源的辐射供冷加新风系统形式分析及能耗计算

辐射供冷加新风空调系统,由辐射吊顶承担部分显热负荷,新风承担全部湿负荷和部分显热负荷。因此,系统需要为新风机组提供低温冷水,达到除湿目的;并需要为辐射吊顶提供高温冷水,防止其结露。目前大多数冷水机组的标准供回水温度是7℃/12℃,本文在采用现有常规冷水机组作为冷源的基础上,通过对系统形式的分析,研究开发出一种能够同时为二者提供不同温度冷源的系统,并分析了其控制策略,最后以某样板房为例,计算出这种系统的单位面积供冷季能耗。     

混凝土天棚辐射供冷的应用探讨

介绍了天棚混凝土辐射供冷的优势;分析了混凝土辐射供冷中天棚最大允许换热能力和室内空气参数的关系、天棚辐射换热量的比例;分析了新风除湿对混凝土天棚供冷的影响以及利用冷却塔进行天棚供冷的可行性。得出的结论对工程实际有很好的指导作用。     

毛细管网辐射供冷与新风复合空调系统在西安市办公建筑应用的可行性分析

通过建立毛细管辐射供冷与新风复合系统的热湿传递模型,对西安地区应用该复合系统的办公建筑在整个夏季的室内空气状况进行了模拟分析,结果表明,整个供冷期系统连续运行的复合空调室内温度不保证率为12.4%,相对湿度不保证率为0,基本能够满足人体热舒适要求;另外,对该复合系统经济节能性与多联机系统进行对比,发现虽然其初投资费用较高,但其运行时较之节能25.3%,若与天然冷源相结合,经济节能性更加显著。因此,西安办公建筑应用毛细管辐射供冷与新风复合系统是可行的。     

毛细管系统在首创天悦西山项目中的应用及设计难点分析

近年来,雾霾肆虐,治理空气污染和解决室内外空气污染已经成为人们的迫切需求,激发了新风+净化系统在高档住宅建筑中逐渐扩张。新风在住宅建筑中应用的同时也激发了毛细管网辐射供冷(暖)空调系统在住宅建筑中的应用。本文以首创天悦西山项目为计算模型,介绍了本项目空调采暖系统形式:毛细管辐射末端系统+独立新风调湿系统。详细分析了新风量的确定原则,为保证毛细管系统运行时不产生结露的风险,保证毛细管空调系统合理的设计,保证新风+毛细管系统较高的热舒适性,提供了一定的设计经验。     

基于辐射空调系统的新风能耗研究

本文以华东地区住宅安装集中地埋管地源热泵+毛细管辐射末端+地板送风空调系统为工程背景,对比了新风冷冻除湿、预冷式热回收型新风处理、热泵式溶液调湿三种新风处理方式的能耗。结果表明,双冷源冷凝排风热回收、热泵式溶液调湿新风处理方式比冷冻除湿分别节能26%~32%、36%。     

Energy performance optimization of radiant slab cooling using building simulation and field measurements

Few field studies of energy performance of radiant cooling systems have been undertaken. A recently constructed 17,500 m² building with a multi-floor radiant slab cooling system in the tower was investigated through simulation calibrated with measured building energy use and meteorological data. For the very cold, dry region where the building was located, it was found that a typical floor of the tower would have had 30% lower annual energy use with a conventional variable air volume system than with the as-built radiant cooling-variable air volume combination. This was due to (1) simultaneous heating and cooling by the existing radiant cooling and air systems, (2) the large amount of free cooling possible in this climate, and (3) suboptimal control settings. If these issues were remedied and combined with improved envelope and a dedicated outdoor air system with exhaust air heat recovery, a typical floor could achieve annual energy use 80% lower than a typical floor of the existing building HVAC system. This shows that radiant thermal control can make a significant contribution to energy-efficiency, but only if the building design and operating practices complement the strengths of the radiant system.     

北京韩美林艺术博物馆空调冷热源及系统设计

介绍了空调冷热源及系统的设计特点和控制方法,详细阐述了土壤换热器的结构及设计形式。采用地板辐射供冷供热结合新风置换通风的方案,重点考虑了围护结构的热工性能、楼板蓄热效应以及防结露措施。采用带室温反馈的室外温度控制方式(前馈-反馈控制)解决了地板辐射供冷系统调节反应速度延迟问题。     

辐射空调冷负荷算法和传统谐波法对比研究

由于辐射空调在舒适性上的优越性,在工程上运用越来越多。在计算其冷负荷时,工程师普遍使用传统的空调冷负荷计算方法。而辐射空调与传统供冷房间存在着传热机理和系统形式的差异,所以传统负荷计算方法不一定适用于辐射空调。首先通过提供一种辐射供冷房间冷负荷计算方法,并通过实验进行验证其合理性,然后对该方法和传统谐波反应法冷负荷计算方法进行模拟对比分析。     

毛细管辐射空调的湿环境控制与防结露措施

毛细管辐射空调系统具有优良的热舒适性能、无室内噪声影响、高效节能等特点,但受系统庞大复杂、造价较高、夏季易结露等因素影响,限制了辐射空调在夏热冬冷及高湿度地区进一步推广应用。在毛细管辐射空调系统小型化和防止结露的探索实践中,采取温湿度独立控制及新风冷凝除湿方式能使结构简化,加大在别墅及高档住宅中应用的灵活性,采取新风除湿和被动式吸湿材料共同承担室内湿负荷的技术方案,以及减少维护结构水蒸汽渗透量和利用"空气湖"效应,有助于避免维护结构表面结露现象。     

Effect of humidity and small air movement on thermal comfort under a radiant cooling ceiling by subjective experiments

Radiant air-conditioning systems are expected to be more comfortable and superior energy-saving systems than convective air conditioning ones generally used. There are some studies on radiant cooling systems. However, they were seldom put to practical use because of dew point problem in Japan. The objective of this study is to investigate the thermal comfort of local parts of the body and the whole body, in particular, including the effects of humidity (45% rh, 65% rh, 85% rh) and small air movements, by subjective experiments under a radiant cooling system. The experiments have been performed by using radiant cooling panels in a climate chamber. Subjects were seated on a chair under the radiant cooling panels, and voted their thermal sensation and comfortable sensation. The following results were obtained. Even in the radiant cooling system, the influence of humidity and small air movement on thermal sensation votes of the whole body could be correctly estimated by using a standard new effective temperature (SET*) within one scale error of thermal sensation. Small air movement with the radiant cooling system had a possibility of improving the comfortable sensation votes in the radiant cooling.     

Experiences with a gas driven,desiccant assisted air conditioning system with geothermal energy for an office building

Thermal driven desiccant assisted air conditioning systems make use of waste heat to dehumidify humid outside air in a desiccant wheel. Within the scope of a research project, an investigation of a desiccant assisted air conditioning system was carried out, and a demonstration plant was built in an office building in Hamburg, Germany. The HVAC system consists of a small CHP-plant, a desiccant assisted ventilation system and an earth energy system (borehole heat exchangers) for cooling instead of an electric driven compression chiller. The radiant floor heating system of the building is used for cooling. In this paper, measurement results and investigations of performance, energy demand and operating costs will be presented. It was found that considerable primary energy savings can be achieved (70%) using desiccant air conditioning with borehole heat exchangers. But even if electric chiller is used, savings of 30% in primary energy can be accomplished. Starting costs for the demonstration plant were not higher than for a conventional system, but running costs could be reduced drastically.     

办公建筑中吊顶辐射空调系统夏季工况性能测试研究

以办公建筑中实际使用的一套金属吊顶辐射板+新风的空调系统为研究对象,对夏季运行工况进行了测试研究。分别对比分析了高温和高湿气象条件下办公建筑室内的温湿度分布,比较了不同高度和不同位置处的温湿度场,在测试条件下,室内有良好的热舒适性。     

地板辐射供冷-置换通风的实验研究

为了研究地板辐射供冷的热工性能,测试了北京地区不同室外气温下地板辐射供冷系统的运行工况,得到了该系统的制冷量,地板表面温度,室内温度场分布等参数,并且把单独地板辐射供冷系统的运行参数与地板辐射供冷-置换通风复合式系统进行了对比,提出了将地板辐射供冷与置换通风配合用于夏季空调室内供冷除湿的新型空调方式,置换通风系统在近地面处形成干燥空气层,可有效防止夏季热湿天气在地板表面出现结露现象,并且使这种新型空调系统条件下地面与室内的换热得到强化.通过理论分析和实验研究指出这是一种舒适、节能的空调方式.