Design and Application of High-Precision Temperature and Humidity Control for Automobile Painting Workshop Based on Sub-Area Division Strategy

According to the characteristic of all-fresh-air air conditioning system for automobile painting workshop, this paper put forward meaningful and referential control strategy of the sub-area division control based on enthalpy-absolute humidity chart (that is i-d chart, which is used for determining air state). Under different operation conditions, corresponding temperature and humidity control curves are studied and applied. The high-precision temperature and humidity control system was designed and realized which is based on European 2604 controller and Monitor and Control Generated System (MCGS) configuration software. Actual operation proves that the sub-area division control strategy can achieve more precious and stable effects than a conventional one. The testing results show that supply air temperature came to stabilization after 15 minutes of air handling units (AHU) start, with the static deviation less than 0.5°C, the maximum dynamic deviation less than 2°C and the supply air humidity is in great agreement with the set point, the maximum dynamic deviation less than 5%.