| Our country is in the high-speed development of urbanization. The predicted total area of new buildings in town is between ten billion and fifteen billion, and one billion of the area is the large-scale public building. Great attention should be paid to these buildings. The area of large-scale public buildings is only 5% of the sum area of civil building in town, but the energy consumption of per area is 10 times of residential construction. The energy consumption of large-scale public buildings is more than total consumption of residential construction in large city or megalopolis, which brings great pressure to our country's energy supply. The research is developing quickly to improving operational energy efficiency of equipment in large-scale public buildings.Developing central air conditioning monitoring system on railway station of GuangYuan city is the background of this dissertation. The dissertation researches central air conditioning monitoring system in large-scale public buildings step by step. With the process of central air conditioning monitoring system of the large-scale public buildings, data acquisition, transmission, storage, statistic and communication have been achieved. Moreover, the database system and application software have been developed.This dissertation introduces a central air conditioning monitoring system in large-scale public buildings based on RS-485 BUS technique, which performs real time measurement of temperature, humidity, pressure, flow, power parameters of the central air-conditioning system. The administrator can monitor the operation and environment conditions in the air-conditioning system by using it.The system adopts multilevel distributed structure and multi-CPU technique composed of the upper set and the lower set. The lower set mainly fulfils the environment data collecting and processing. Then the data will be transmitted to upper set through RS-485 BUS. The upper set displays the data transmitted by the lower set in turn and gives off an alarm signal when the data is beyond the threshold value that was set by users. The upper set performs the lower set address setting, the lower set working condition inquiring and the threshold value of environment element setting and then achieves uniform management of the Central air-conditioning system. Adopting multilevel distributed structure not only avoid the loss of analog signal caused by long-distance transmission, but also simplifies the wiring and facilitates adding the amount and sorts of sensors. The system is easy to be extended and upgraded.The dissertation completes both the software and hardware design and presents a kind of central air conditioning monitoring system that can be applied to large-scale public buildings. |
