Analysis Of Energy Consumption And Control Of The Air-water Type Central Air-conditioning System

The air-conditioning system is designed in the case of maximum load with a small quantity of margin. So the air-conditioning system will waste a lot of power when its motor works under the conditions of fixed temperature difference and full power, when the load is varies as time went by. So the converter technique is a significant measure, which is energy-saving of central air-conditioning.The WSC-W single cooling type air conditioner, which is usually used in the north of China, is the mainly object of study. It contains the cooling system centered its work in refrigerating machine and heating system centered its work in boiler. So analysis the energy consumption of the winter heating system and the summer cooling system, respectively is necessary.This study was based on the basic idea of modeling analysis, a comprehensive analysis of the overall energy consumption of winter heating and summer cooling system. Operating characteristics of the various components of system to gain the decision variables and constraints, and use analysis of mechanism modeling method to obtain the objective function which is universal in nature. The specific parameters of the research is brought into the central air-conditioning system object model, under the premise of satisfying the constraints by using MATLAB optimization toolbox optimal solution(temperature difference) in case of a load. Use MATLAB simulation analysis to verify the feasibility of the optimal solution of the program.Then, set up a central air-conditioning control system. The topic chose Siemens S7-1200 PLC as core controller, PLC is written by using the TIA Portal V11 software program, WinCC software is used to build configuration screen. PID is selected as control strategy, drawn from the analysis of the optimal solution for the return water temperature as the PID setpoint input, the output value of the PID is used as actuators- the inverter’s input, the motor speed is controlled by inverter, thus changing pipeline to regulate water flow rate and adjusting the temperature difference between the control objectives. And set up a remote concentrated meter reading system, aimed at analyzing and collecting the power consumption by a special software.