Research on optimization control of cooling tower outlet water temperature in a building centralized air conditioning system based on HOA

To solve the optimization problem of the control setting values of the cooling tower outlet water temperature in a building centralized air conditioning system, the operation simulation of the building centralized air conditioning system is carried out based on the coupling calculation method of the building envelope and centralized air conditioning system. Given the different influencing trends of the control setting values of the cooling tower outlet water temperature during system operation on the chiller and cooling tower energy consumption, a new population-based algorithm, the hippopotamus optimization algorithm (HOA) is proposed to optimize the control setting values of the cooling tower outlet water temperature under the goal of minimum energy consumption. Taking an office building as an example, the effects from the different control setting values of the cooling tower outlet water temperature in three control schemes on the operation energy consumption of the chillers and cooling towers are compared through dynamic simulation and optimization. The results show that the optimized control setting values of the cooling tower outlet water temperature can be obtained by using the HOA scheme, and the lowest operation energy consumption of the chiller and cooling tower can be achieved under the setting value. Compared with other algorithms, the performance of the HOA optimization process is better, the optimized fitness value is the smallest, the function converges when the number of iterations is 5 times, and the optimization of 1 moment can be completed in only 2.10 s when MATLAB is running. Compared with the common non-controlled and non-optimized working conditions, the typical daily maximum energy-saving rate is 3.49%, and the average daily energy-saving rate is 3.05%.