A novel pulse width modulation for metal radiant panels to control the condensation risk in a hot and humid environment
A novel pulse width modulation for metal radiant panels to control the condensation risk in a hot and humid environment
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一种用于金属辐射板的新型脉宽调制，可控制湿热环境中的冷凝风险
DOI：
10.1016/j.buildenv.2021.107802
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发表时间：
2021
影响因子：
7.4
通讯作者：
Li Chunying
中科院分区：
文献类型：
--
作者：
Tang Haida;Zhang Tao;Liu XiaoHua;Li Chunying
为控制湿热环境下金属辐射板的冷凝风险，提出了一种新型的表面冷凝蒸发循环脉宽调制(PWM)控制方法。通过开关式电磁阀，整个脉宽调制周期由一个固定的开关期持续时间，即20分钟和一个可调的关断期持续时间组成，以保证在开关期内，面板上形成的冷凝水在关断期结束时完全蒸发。利用经过实验验证的散热板传热数值模型，对脉宽调制的动态热性能进行了评估。根据模拟结果，整个循环内的最大累积冷凝质量远远小于冷凝液滴的下降标准，表明了脉宽调制在消除表面冷凝对室内环境的负面影响方面的能力。此外，与供水温度等于露点温度的变温控制方法相比，采用脉宽调制的辐射板的制冷量提高了10%。采用脉宽调制技术的辐射金属板在湿热地区围护结构气密性较低的建筑改造中具有较好的应用前景，可显著降低冷凝风险。
A novel pulse width modulation (PWM) control method with surface condensation-evaporation cycle was proposed for metal radiant panels to control the condensation risk in hot and humid environments. Through an on-off solenoid valve, a whole cycle of the PWM consists of a fixed on-period duration, i.e., 20 min and an adjustable off-period duration in order to guarantee the formed condensate water on the panel during the on period evaporated completely at the end of the off period. A numerical heat transfer model of the radiant panel validated by experiment was utilized to evaluate the dynamic thermal performance of the PWM. According to the simulation results, the maximum accumulated condensation mass in the whole cycle was far smaller than the falling criteria of condensate droplets, revealing the ability of the PWM in eliminating the negative effects of surface condensation on the indoor environment. Furthermore, compared with the variable temperature control method with a supply water temperature equal to the dew point temperature, the radiant panel utilizing the PWM provided a 10% higher cooling capacity. The radiant metal panels using the PWM has an application prospect for retrofit buildings with low airtightness of the envelope in hot and humid regions by a significant reduction of condensation risks.