Fundamental Study on the Exergy-Entropy Process of Buildng Environmental Control Systems

传统的关于建筑环境控制系统工作原理的理论仅仅是基于能量守恒定律。我们试图将这一理论扩展到包含熵产生定律和相关概念(火用)的理论。对冬季某一天太阳辐射透过窗户和外墙表面喷水引起的室内空气温度变化进行了简单的算例计算。以下是调查结果。火用与太阳辐射能之比在80%~90%之间。长波有效天空辐射所包含的(火用)总是出现在外墙外表面。在日本夏季，其排放量约为1W/m^2。我们把湿空气的火用分为温暖、凉爽、潮湿和干燥四种。根据这一分类，湿空气中的液态水作为环境的火用或暖或冷的火用和湿的火用。研究发现，蒸发冷却是一个消耗湿(火用)水并产生放冷量的过程。根据测量的太阳辐射和太阳位置估算了树木的消光系数。将所提出的估算穿过树木的太阳辐射的方法与现场测量的结果进行了对比检验。太阳辐射估计值与实测值吻合较好。将实测的室内空气温度与计算的室内空气温度进行比较，两者吻合较好。人们发现，地球有一个系统来处理地球表面产生的所有熵，这些信息是由于太阳在各种情况下消耗(火用)而产生的，包括被动加热和制冷。

The conventional theories associated with how building environmental conrtol systems work are only based on the law of energy conservation. We have tried to extend the theory into the one which includes the law of entropy generation and the associated concept, exergy. We have made simple example calculation in terms of room air temperature variation caused by solar radiation transmitted through windows on a day in winter and water spraying over exterior wall surfaces. Following are the findings.1. The ratio of the exergy to the energy of solar radiation is between 80 and 90%.2. The exergy contained by the long-wave effective sky radiation always comes at at the outer surface of exterior walls. Its amount is about 1W/m^2 in summer in Japan.3. We classified the exergy of humid air into warm, cool, wet, and dry exergies. According to this classification, the liquid water in humid air as the environment contains either warm or cool exergy and wet exergy. It was found that the evaporative cooling is a process that consumes the wet exergy of water and ther by produce the cool exergy.4. The extinction coefficient for the trees were estimated from the measured solar radiation and the solar position. The proposed method to estimate the solar radiation coming through the tree was tested against the resultof the field measuremant. Solar radiation estimated was in good agreement with that measured. The measured room air temperature was compared with the calculated room air temperature and both temperatures were in good agreement.5. It was found that the earth has a system to dispose of all the entropy generated by the earth surface due to the consumption of solar exergy for various puposes including passive heating and cooling.