外文翻译-----冷却塔.doc

If a chiller is used to provide chilled water for building air conditioning, then the heat energy that is absorbed through that process must be rejected. The two most common ways to reject thermal energy from the vapor compression process are either directly to the air or through a cooling tower. In a cooling tower, water is recirculated and evaporatively cooled through direct contact heat transfer with the ambient air. This cooled water can then be used to absorb and reject the thermal energy from the condenser of the chiller. The most common cooling tower used for HVAC applications is the mechanical draft cooling tower (Figure 4.2.13). The mechanical draft tower uses one or more fans to force air through the tower, a heat transfer media or fill that brings the recirculated water into contact with the air, a water basin (sump) to collect the recirculated water, and a water distribution system to ensure even dispersal of the water into the tower fill.

如果冷却塔设备被用来向建筑空调提供冷却水，在这个过程中冷却水吸收的热能必须释放掉。释放蒸汽压缩过程产生的热能的两个最常用的方法是直接用空气冷却和用冷却塔。在冷却塔内，水在被不断循环蒸发中与周围空气进行热量交换。这种冷却水能够被用来吸收释放冷却设备冷凝器的热能。暖通空调应用中使用最广的冷却塔是机械通风冷却塔（如图4.2.13）。机械通风塔用一个或多个风机推动空气在塔内的流动，用一个换热器或填料层使循环水与空气充分接触，用一个水箱来收集物质循环水，和一个配水系统来确保水分散在塔的填料层中。
图4.2.14表示循环水和空气在逆流式冷却塔内相互作用的关系。蒸发冷却过程即水和空气充分接触，包括了同时进行的热质的交换。理想状态下，水通过配水系统形成飞溅或分裂成较小的水滴，增加了热交换中水的换热面积。通常用湿球来表示塔的大小和工作情况。它被定义为出塔冷却水和进塔空气湿球温度之间的差值。理论上，水在塔内循环可以到达湿球温度，但在实际工作中是不可能实现的。