Simulation And Energy Saving Optimization Of Central Air-conditioning System

According to analysis data, energy consumption mainly divides into 3 parts, as industrial energy consumption, building energy consumption and transportation energy consumption.Building energy consumption accounts for about 30% of all the energy consumption, and central air-conditioning system takes the largest proportion for around 65%. With emphasis on energy problems and high requirements of energy conservation, it plays an important role to decrease the energy consumption of central air-conditioning system.This paper gives an optimal operation strategy to run a central air-conditioning system based on the analysis of the variable primary flow system in some office building in Shanghai. This paper concludes with the help of simulation software TRNSYS which conducts a model of system units and system platform.The basic knowledge of central air-conditioning system is introduced in this paper, like primary and secondary flow systems, variable and constant flow system, variable air volume system and constant air volume system. It puts forward practical control strategies of variable primary flow system and variable air volume system, including water chiller control strategy,circulating water pump control strategy, cooling tower control strategy, fresh air control, AHU control, end control strategies.In this paper, mathematical model is modified with some actual system operating data. This paper has made the accuracy test and is verified to make sure the model is correct. The simulation model is constructed with all system units and their parameters in TRNSYS after the accuracy test to provide a solid platform for the subsequent research analysis of control strategy.In the end, based on the simulation platform, this paper proposes the system operation strategies to increase the supply chilled water temperature. This paper concludes that comparedwith the traditional 9℃ supply chilled water, the system energy consumption decreases about17.9% with the 9℃ supply chilled water and the indoor AQ is affected little by comparing the energy consumption under different supply chilled water temperatures. This paper also gets the results that variable air volume system can save 14.3% energy consumption compared with constant air volume system by using the simulation platform to simulate the energy consumption of the 2 systems.