The Research On The Application Of LonWorks Technology Into Variable Air Volume System Control

In the 21st century, the era of energy shortage, researches on energy conservation of high-rise buildings are strategically important. As a monitor facility, research platform and implement instrument of energy conservation of high-rise buildings, intelligent building is playing a more and more important role. The Variable Air Volume (VAV) system is widely used in air conditioning system design of high-rise buildings' due to its potentials in energy conservation and advantages in providing comfort. Control of a VAV air conditioning system is the key point and also a nodus of a sound VAV system due to the separation of controlled devices and the strong conjunction of controlled variables.This paper introduces Lon Works technology into VAV control system, analyses theoretically the control schemes of VAV control system and develops the control programs based on Lon Works-supported building automation system.The author works on the thesis in Beijing Acorp M&E Company, participates in scheme design, equipment selection and quoting, and controller programming and system commissioning of Building Automation System of one mansion in Beijing City, which introduces VAV system in air conditioning system design.Based on extensive literature review, this thesis analyses and compares different VAV system forms, different VAV terminal forms and different VAV system control schemes, points out the limits of static pressure-based control scheme. This thesis introduces "total volume method" into VAV control schemes, and analyses its advantages. This thesis put forwards an optimum cooling control method in supply air temperature set-point control of VAV air handling unit, which extends the control range of VAV terminals and reduces system energy consumption. On the foundation of theoretical research, the author develops VAV controller programs based on Lon Works-supported building automation system, which are used in the building automation system programming and commissioning of one mansion in Beijing City. This thesis provides reference and evidence of the application of Lon Works technology, a new control networks technology, into VAV control system.