Comprehensive Energy Conservation Methods and HVAC Management
Location: University Campus
Products Used: WebAccess Software, BAS-3520 DDC
Most of the control strategies for the existing central air conditioning systems dwell upon the optimization of one subsystem or partial parameters, short of a comprehensive energy saving scheme and energy efficiency analysis software as tools to achieve high efficient management. This project, in order to meet demands for system energy saving, aims to revamp and upgrade system equipment which involves the frequency conversion of chilled water pumps, air-handling units, cooling towers and fans so as to optimize their control algorithms. It also includes the design of an efficiency management software tool based on WebAccess and BEMS, and a VAV terminal controller based on BAS-3520 DDC to improve operation efficiency of the air-conditioning system. The system thus is expected to save 15% of energy according to a primary assessment.
The field-level sensors and power transmitters send signals to PLCs by RS485 protocol, and the PLCs send received messages to the upper computer by TCP/IP protocol, which are then collected by WebAccess via an OPC interface. The WebAccess is in charge of monitoring and controlling the operation of the whole system, while the BEMS of implementing statistical analyses of energy consumption at specific devices. The WebAccess monitors and controls wind system, ice-water system, VAV boxes, statistics of the system’s energy consumption (including energy consumption structure analysis, coefficient of performance (COP) analysis, cooling supply capacity analysis and water flow parameters analysis), and energy consumption statistics provided by Advantech’s BEMS device.
With the energy efficiency management system based on WebAccess and BEMS, the user is able to acquire real time data of the load system devices, and set parameters for remote equipment via the Internet. The VAVBOX device based on BAS3520DDC is able to meet system requirements and has good market prospects. With BEMS one can search and query historical trends of power consumption and make comparisons. Meanwhile, with WebAccess platform for power consumption statistics one can figure out COP value and cooling capacity of the system. In the end, the air conditioning system is able to achieve high efficient management and meet the goal of saving 15% of energy.