Simulation And Control Research On The Indoor Part Of Variable Refrigerant Volume Air-conditioning System

Variable refrigeration volume air conditioner (VRV) is widely used recently due to its merits such as effectiveness, comfortably. There stands obvious technology gap between home and abroad due to the complexity of VRV Air Conditioning System. Furthermore, it has the important meanings and value to research because of the variety of VRV air conditioners.In this thesis, the indoor parts (EEV and evaporator)of the VRV air conditioning system is studied by the way of mathematical simulation. Analyze the laws of the indoor parts' characteristic and the running values. Furthermore, the author searched an advantaged PID control method based on the settled superheat. The main work is as followed:First, based on special state equations, a program is developed to calculate the thermo-property of R410A. Mathematical modes of the electronic expansion valve(EEV) and the evaporator are set up. Calculate the mathematical modes and analyze the affect to the characteristic of the evaporator when the other parameters are changed, such as the wind power and wind temperature. Based on the mathematical modes calculate the transfer function of the evaporator, analyze the influence factors of the special parameters. Calculate the transfer function when the superheat is settled.At last, based the transfer function, use the integral separated PID to control the EEV opening and gained the response curve. Compared to the tradition PID, the result is , the advantaged PID is better.