Model-based energy analysis of a dry room HVAC system in battery cell production

Abstract

The operation of drying rooms is an essential part of battery cell production, in order to provide a save and well conditioned environment during the cell assembly. A specially dimensioned Heating, Ventilation and Air Conditioning (HVAC) system is required to operate a dry room, which depends on a large number of parameters and accounts for a substantial part of the total energy demand in battery cell production. Therefore, a dry room significantly contributes to the energy embodied in battery cells and affects their cost and environmental footprint. In this context, model-based, quantitative analysis are of interest in order to dynamically evaluate the effects of changed of ambient conditions at different locations. In this paper, we investigate the operation of an existing drying room through a case study at the Battery LabFactory Braunschweig with a physical simulation model. We validate the model against recorded measurement data in high temporal resolution. The model is able to represent the measured data of the total energy demand over one month at an hourly time step with only 3.27 % deviation. Using the validated simulation model of the HVAC system, we examine the operation of the system at different locations regarding their economic and ecological footprint. To achieve this, we virtually relocate the system to five different locations around the world and operate it over a typical year at each location. We carry out an economic and environmental assessment for each site under consideration and for each location we report relevant KPIs that are independent from production throughput and potentially transferable to other use cases. Such investigations allow interesting findings to be derived for practical applications in brown-field applications, but also for the planning of new systems at different locations.