Analysis On Host Energy Consumption And Research On Water System Energy Saving Control Of Central Air-Conditioning System

Nowadays the society is facing increasingly serious energy crisis, the energy conservation has attracted more attention. With the development of economy, the consumption of building energy is bigger and bigger, and the central air conditioning system is the indispensable energy system of modern architecture, accounts for about 70% of building energy consumption, while the water system is an important part of air conditioning systems, its energy consumption can account for about 60 % to 70% of air-conditioning energy consumption. The design of air conditioning system is according to the maximum load, but in actual operation, the system operates under partial load in most time, therefore, study the energy-saving optimization control of water system has important significance.As the main energy consumption system of the central air-conditioning system, research did on it at home and abroad are great, but the control parameters in these studies are signal and without considering the comprehensive study of energy-saving. There are relations between the system parameters, and signal parameter optimization can not reduce the system total energy consumption, so it is necessary to study the overall operation consumption of the water system. First, in this paper, study the efficiency features and energy-saving methods of central air-conditioning system, and based on these, establishes energy consumption models of the main parts of water system and the overall energy consumption model of system. According to the established energy consumption models, study the best chilled water and cooling water flow that can make the energy of unit and water pump minimal, aimed at different load conditions, put forward the best chilled water or cooling water relative flow. In view of the actual conditions, chilled water and cooling water flow change, a kind of changing chilled water flow and cooling water flow energy optimization control scheme based on minimal energy consumption is proposed, this method can optimize the parameters online according to the information collected. According to the water system's energy optimization mathematical model established and the corresponding constraints, do simulation research on the control scheme, and get the best chilled water and cooling water flow under different loads. The results show that the method can reduce overall system's power consumption, and improve overall performance coefficient of the system, provide a certain reference value to actual projects. Second, for system using different rated-capacity chillers put forward the load distribution strategy based on minimal energy consumption, and uses the improved PSO algorithm to do optimization simulation research, the results show that this method can effectively reduce the system's total energy consumption with the actual reference value to actual project. Finally, for the parameters tuning of PID control is difficulty, and control effect is not ideal, put forward PSO-BP neural network predictive control based on chaos optimization for water system control, the simulation research on MATLAB shows that the dynamic performance of the method is better than PID control.