Research And Implement Of Fan Coil Unit And Hydroponics Systems Variable Frequency Control System In Central Air-condition For Energy Saving

With the rapid developing of national economy and energy demand increased, energy saving and reduce greenhouse gas emissions are paid much attention to. How to reduce energy consumption and improve the energy utilization efficiency are determined the continuable development of economy and society. According to statistics, the energy consumption of central air-condition system accounts for about 60%~70% percentage of the total energy consumption of building trades. Traditional central air-condition system usually is based on constant flow and the Fan Coil Units are also adopted step-type speed regulation. The design and the auxiliary equipments selection of air-condition system are usually according to maximum load of the building, and also have a margin. But owing to the load of building is varied with outer environment temperature, which is varied with the summer and the day and night. And this leads to the needs of central air-condition load dynamic change. To solve the problems, convert constant flow into variable flow can make the central air-condition system loads adjust to the actual loads of environment.This research analyses the theories of variable flow hydraulic system and the frequency conversion control of FCU motor for central air-condition system energy-savings, aimed at the problem that the existing control system is complicated, the control parameters are excessive, the control way is complex, the system response rate is slow, and so on, and then a novel control scheme is given. Based on the energy waste of constant flow hydraulic system, the design of FCU and the operation, this thesis gives a energy-saving control scheme that the constant flow hydraulic system is converted into variable flow hydraulic system, and the frequency conversion control of FCU motor, which make the central air-condition system load adjust to actual load of the building, and aim at energy-saving.Based on summarizing the background and significance of this thesis, the actuality and trend of development of the central air-condition control system, this thesis gives the main contents, confirms the general design scheme of the central air-condition system, and expounds the design of software and hardware of the control system. And then illustrates the research and implement of the control system equipment of this thesis. At last, to summed up this research.