In its on-going effort to help reduce aviation’s contribution to climate change, Airbus has designed and built an innovative paint booth for its new-generation A350 XWB jetliner that uses significantly less energy than standard facilities, while also minimizing CO2 emissions.
Airbus’ current livery painting process requires a constant temperature of 21-26 ˚C, as well as a humidity rate between 45 and 70%—which presents a particular challenge during summer and winter months, when more energy is needed to overcome hot/cold outside temperatures and maintain the necessary conditions for painting.
Now in service at Airbus’ Saint-Nazaire plant in France, the new paint booth recovers heat from the paint shop using a rotary heat exchanger called an enthalpy wheel. Enthalpy wheels, which are used in HVAC systems, exchange heat and humidity from one air-stream into another. An enthalpy wheel is a large turning disc made out of a metalic honeycomb material (e.g., aluminum) that is coated with a desiccant.
Sensible heat is transferred as the metallic substrate picks up and stores heat from the warmer air stream and gives it up to the cooler one. Latent heat is transferred as the desiccant coating on the metallic substrate adsorbs moisture from the air stream that has the higher humidity ratio and releases the moisture into the air stream that has the lower humidity ratio.
To complete the system, the project team replaced gas-heated boilers with a CO2 heat pump—heating water to 85 ˚C and furnishing 21 ˚C inside the booth, eliminating the CO2 emissions from gas combustion.
This project is giving a 67% saving in energy use and an 86% reduction in CO2 emissions, with the remaining 14% CO2 emissions coming from the electrical power required for fans and the heat pump. The huge advantage of this project is that it can be applied across all our paint shops on other sites. With a return on investment of four years, this project is really leading the way for future energy reductions and achieving zero CO2 emissions from our industrial processes.—project leader Pascal Danthony