摘要
辐射冷却吊顶是在国外,尤其是欧洲国家普遍采用的中央空调系统形式之一,它主要用于办公、医院、学校等级别较高的建筑。为了提高辐射吊顶的冷却能力,保证室内合理的气流组织,辐射吊顶往往结合机械送风系统使用。机械送风的形式有两种:置换通风和独立新风。根据我国的具体国情,辐射冷却吊顶结合独立新风系统是最佳选择,这种形式的空调系统具有舒适性高、噪声低、系统无回风、无冷凝水、安装检修方便等诸多优点,符合现代人对舒适、健康、节能空调系统的要求。
由于辐射供冷发展的历史以及国家气候、经济、文化等多方面的原因,人们对辐射供冷一直存在偏见,认为该系统容易结露,初投资过高,而且辐射板本身的冷却能力有限,因此适用范围狭窄。文章对以上三点疑虑进行了详细分析,纠正了这一错误的传统认识,从理论上证实了辐射供冷空调系统的可行性。
辐射板作为辐射冷却吊顶的主要设备,其热工特性直接关系到辐射冷却吊顶的性能。从理论上分析,可以将辐射板看作肋片结构建立数学模型,根据传统的辐射供冷理论和经验式,得出辐射板在实际运行时的冷量计算方法。山于辐射冷却吊顶应用的条件不同,辐射板生产厂家必须根据已有的测试标准对辐射板冷却性能进行测试。
因为国内至今仍无生产辐射板的厂家,所以进口产品昂贵的价格成为阻碍辐射供冷空调系统在我国应用的主要障碍之一。为了在我国推广辐射供冷空调系统,国内最新研制成功了一种新型辐射板,它具有结构简单、价格低廉的特点,经测试其供冷能力超出国外同类产品将近两倍。最为特殊的是,该辐射板的表面在经过憎水膜处理后,从根本上解决了辐射板凝露的问题,为辐射供冷在国内的广泛应用提供了可能。
Radiant cooling ceiling (RCC) is popular in oversea primarily European countries. It is widely used at high level buildings that need ceiling such as offices, hospitals and schools. Due to its limited cooling capacity, RCC is often combined with mechanical ventilation systems. There are two kinds of ventilation systems for us to choose: DOAS (Displacement and Dedicated Outdoor Air System), between which DOAS is fitter for native use. When radiant cooling ceiling is used as terminal device of DOAS, this system will perform excellently in affording good comfort, low operation noise, higher air quality by elimination of return air and condensation, what's more, the module panel design makes fitment and repair works more convenient. These advantages satisfy all personal demands for air conditioning system.However, the development of RCC suffers setbacks and leaves bad impression in people's mind as easily get condensation, high first cost and small cooling capacity. Modern RCC overcomes the above defects. This article explains in detail to get rid of those old biases and prove the application of RCC is possible.As the composing part of RCC, RCP (Radiant Cooling Panel) focuses on enhancing its heat conduct performance and cooling capacity. We can take the RCP as fin structure, and then build a computation module to get its actual cooling capacity at application occasions. Because RCP can be used in complicated situations that will result in different performances, merchant products should be sold with lab testing results with national standard.Till today, there is no native RCP producer in our country. The expensive price of imported RCP becomes the obstacle of application of RCC system. To our joy, we have lately developed a kind of RCP of completely new simple frame. According to the test results of Xi'an Jiaotong University, this new panel trebles cooling capacity compared with imported ones. The most worth noticing thing is the adoption of superhydrophobic technique in the panel surface processing. After getting on this special membrane, no water is able to stick on the panel surface even in extreme situations. Thus condensation is cleverly resolved and simplifies the control system for panel water loop.
引文
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