An integrated method for assessing the energy efficiency of machining workshop

Increasing pressures from energy price and environmental directive force the manufacturing enterprises to consider and initiate the implementation of energy assessment and energy quota practices to improve both their economic benefit and environmental performance. Against this background this paper presents an integrated method to evaluate energy efficiency in machining workshop. The integrated features of the assessing method are reflected in three aspects: (1) In this evaluation system, the energy profile of machining workshop is viewed from the machine tool layer, manufacturing unit layer, task layer and workshop layer to reveal the energy performance inside the workshop completely. (2) The assessing indexes for each layer include both effective energy indicator and Specific Energy Consumption (SEC) indicator. (3) An integrated calculation method of energy indexes is introduced, which combines off-line experiments with theoretical formulas. To verify its feasibility and validity, the assessment method is applied to a small machining workshop. The assessing results showed that the assessment method is helpful in providing support for machining scheme selection, energy saving discovery and energy quota allocation in plant, which has significance in practice.