Intelligent Control Technology Research And Embedded Achievement Of Miniature VRC Entral Air-Conditioning

With the improvement of living standards in recent years, air-conditioning demand is also rising. Especially in the summer, air-conditioning load in China accounted for a larger proportion of the electricity load. In Beijing, the summer peak load of approximately 3.8 million kilowatts in 2007, accounting for the entire electricity consumption in Beijing by 40%. Air-conditioning energy consumption has become one of the issues can not be ignored, so energy conservation of air-conditioning systems and reducing operating costs has an important significance of the national economy sustainable development.This thesis concerns miniature Varied Refrigerant Volume (VRV) central air-conditioning as research object. On the basis of a detailed analysis of working principle for the miniature VRV central air-conditioning system, an intelligent incremental discrete PID control strategy is proposed for controlling degree of superheat of the central air-conditioning system, to make sure the superheat of evaporator is stability. Meanwhile, the corresponding evaporator cooling capacity is also better, related COP values are higher. Based on this control strategy and with the research of embedded systems hardware development platform with Samsung S3C2410 as CPU, an embedded controller for of miniature VRV central air-conditioning is designed.Based on the hardware platform above and embedded Linux operating system, this thesis set up a cross compiler environment for embedded software development of miniature VRV central air-conditioning controller, and detailed analyzed cutting and compile Linux kernel, root file system set up, application design and controller software design flow. On this basis, completed embedded software development such as the control algorithm subroutine, temperature sampling filtering subroutine, electronic expansion valve driver and SIM card communication subroutine and so on. Through the software development mentioned above, the established control strategy is achieved, so that miniature VRV central air-conditioning intelligent embedded controller has achieved the purpose of optimal control of evaporator superheat degree.In order to verify the practical application of the controller, this thesis simulated the HVAC refrigerating machine system platform as the VRV central air-conditioning evaporator superheat section, and experimental tested. The results show that the system superheat has a largest steady-state fluctuations less than 1°C, and achieved optimal operation of the system.