Operating Characteristics Research Of Cooling Towers Based On Micro-Climatic Conditions

The actual operating environment of cooling tower differs from design conditions because of limited space, layout position and local climate characteristics. Cooling tower runs under the local environment and its operating characteristics is subject to the constraint of the particular micro-climatic conditions. Mutual interference between towers can cause a decline in the efficiency of a single cooling tower and towers control and regulation are much more complex than a single tower. The performance of air-conditioning system is impacted by the running performance of cooling tower which is the cooling water side end of air-conditioning system. Therefore, it is necessary to study the operating characteristics of cooling towers under micro-climatic conditions.The thermodynamic model based on counterflow cooling tower was set up and evaporation loss, characteristic number, Lewis number and hot reflux were taken into account. The operating characteristics of a single tower under different climatic conditions and the operating characteristics of towers under different control are discussed. The results show that the higher the dry bulb temperature and humidity are, the lower the allowable inlet water temperature and heat dissipation are, and the greater the required air flow is. Asynchronous speed adjusting causes the frequency tower exhaust temperature and humidity to become higher, and the total energy consumption is also much larger than synchronous speed adjusting.The simulation model is verified by the experimental results of the counterflow cooling tower of a administration building, which reveals that the maximum relative error is below 5.46%. In addition, the experimental study on the operating characteristics of counterflow cooling tower suggests that the lower the control water temperature is, the longer the outlet water temperature needs to reach the control target at the same inlet water temperature, and the greater the adjusting inertia is. Meanwhile, the lower the control water temperature is, the longer the period of cooling tower drive spends, and the greater the motion is. The experimental water temperature difference can reach 4.83°C when control water temperature difference is 5°C, and the deviation between them is only 3.4%. Finally, the optimal operating frequency of cooling tower under different system loads is obtained.