Energy Equivalent of Compressed Air Consumption in a Machine Tool Environment

Compressed air has many applications in machine tools. Compared to the potential energy stored in the fluid tank its production requires a large amount of energy. In addition to the potential energy, heat loss does occur as by-products. Dependent on the amount of heat loss, energy consuming cooling is required. For life-cycle investigations of machine tools, the gray energy and environmental impacts of compressed air consumptions have to be known. This work presents a theoretical approach to quantify the energy equivalent of compressed air and its by-products. A model based approach is set up to describe the required physical relationships for the compressor and its peripheral components. Measurements obtained from a shop floor compressed air supply have been used to validate the results of the theoretical approach. Concluding from the analysis, a general approach for the theoretical energy equivalent calculation, including the compressor and treatment of heat loss, is possible.