Around a third of the total energy consumption of a paint shop is currently attributable to air conditioning. With the further development of Smart AC from DXQequipment.analytics, Dürr has developed an intelligent control system that allows operators to operate supply air systems in an energy and operating cost-optimized manner for the first time.
Energy savings thanks to flexible control window
Until now, supply air systems have generally been set to rigid setpoints that maintain the greatest possible distance from the critical limit values for the paint application. This often results in more heating or cooling than necessary. The digital solution makes it possible to control supply air systems quickly and precisely within a defined range. Smart AC calculates an energy-optimized range for temperature and humidity. The minimum and maximum values form the limits of the setpoint range that the system operator sees on a screen. The larger this control window is, the less energy is required to regulate the heating and cooling capacity as well as the water input. "Instead of using a lot of energy to set a fixed point value of 23°C, for example, the temperature can be set flexibly between 21°C and 25°C. This reduces consumption while maintaining the same high coating quality," explains Jens Häcker, Vice President Digital Factory at Dürr.
Sample calculation for the savings
The scope is illustrated by an example with the following assumptions: The capacity of an air supply system for basecoat and clearcoat lines is 350,000 m3/h. The plant requires 80 % recirculated air and there are 30 % critical days with weather fluctuations to which it is necessary to react quickly. Almost irrespective of the location, the annual energy costs for the flexible window were around 30,000 euros lower. The more expensive the energy and the warmer and more humid the climate at the respective location, the greater the savings.