Performance Analysis And Diagnosis For Cooling Tower In Central Air-conditioning System

With the use of air conditioning system is more and more common, the energy consumption of the air conditioning system is more and more large, the energy consumption has become an increasingly important issue. The energy consumption of the air conditioning system is the main part of the energy consumption of the building operation, reduce the energy consumption of the air conditioning system is the key to building energy efficiency. Cooling tower is the cooling device air of the conditioning system, The cooling tower operation is in accordance with the design requirement or not, not only affects itself energy consumption, more is mainly influences the condensing temperature of the refrigeration unit, thus influences the COP of the refrigerating units, ultimately affects the energy consumption of the entire air conditioning system. So diagnosis analyzing the performance of the cooling tower, making the cooling tower always efficient operation, is an essential part of the energy research of the air conditioning system.In this paper, according to the enthalpy difference equation of Merkel, a performance evaluation method of the cooling tower is put forward and use the performance evaluation method to diagnose the cooling tower performance.The evaluation method use the data measured of the outlet temperature of cooling water, gas-water ratio, inlet temperature of cooling water and so on, to calculate the temperature calculated of cooling water. The two indexes of computational efficiency and thermal efficiency are used to diagnose the performance of the cooling tower meeting the requirements or not.This paper also analyzes separately, the influence of the cooling water flow to the cooling tower efficiency. In different numbers and combination of the running cooling towers, the proportion of the cooling water flow measured of the single cooling tower accounting for the total flow measured is compared with the proportion of the cooling water flow rated of the single cooling tower accounting for the total flow rated of the running cooling towers, to reasonably judge that the cooling water flow is in balance or not, and further analyzes the influence of the cooling water flow to the cooling tower efficiency.This paper uses the data measured of the two building of real estate Company, in Hong Kong, through writing software to monitor the cooling tower operation state; Draw operation efficiency curve and flow operation curve, and validate the applicability of the method used to diagnose the performance of the cooling tower and the reliability of the flow balance determination method. Through the online and offline program operation, the two methods are well used for evaluating the cooling tower efficiency and the judgment of flow balance.