Automatic Control System For Comfort Air Condition System

The first target of Comfort Air condition System is to maintain the suitable indoor environment for the people. Comparing with the traditional A/C system, the comfort air condition system can not only adjust the indoor temperature, but also create"Suitable indoor environment"for people, including temperature and humidity control, CO2 and VOCs discharge, Virus and Bacteria sterilization, fresh air intake and air distribution design.The second goal of the Comfort Air Condition System is to reduce the power consumption and increase the power efficient for the building. With the China economic development, a lot of big buildings such as super-mall and skyscrapers have been built. According to statistic; in the commercial building, more than 50% to 70% percent of the power is used for the HVAC system, in order to meet the maximum cooling and heating demand, the HVAC system is designed to run in full load. But most of the working season for HVAC system is as part load. In order to saving the energy in part load situation, more and more engineers focus on the HVAC operation management and control logic design.A/C automation control system is the most important element for Comfort Air Condition System control and management. Though the A/C automation control system, we can operate, manage, collect the running data and pre-diagnose all the HVAC devices in on single central computer, the computer can communicate with chiller, water pump, cooling tower, piping system and AHU through the DDC.This paper is based on the HVAC application of Nanning government building to discuss ideas of the HVAC power management and comfort indoor environment maintenances. In order to reduce chiller power consumption in part load situation, the"start-up sequence based on the highest COP curve"is the good control strategy for multi-chillers system; for condensing water pump operation, this paper provide a Fuzzy-PID combining control logic for primary pump variable water flow volume system to meet the robust and accuracy. For AHU and VAV box, this paper also gives the"minimum static pressure"control logic.This paper also provides some good ideas for the"comfort indoor environment maintenance", In order to improve the IAQ, the ventilation volume is most important for HVAC system, but high ventilation volume will also reduce the power efficient, in order to balance the power efficient and IAQ, this paper describes the Fuzzy-PID control logic for DCV (demand control ventilation), this paper also introduces how to separately control the indoor air temperature and humidity to meet the"constant temperature and humidity control"requirement.