Phase Change Material Thermal Energy Storage (PCM-TES) for ECU Efficiency Improvement

This proposal presents an hourly thermal load analysis for shelters cooled by 9,000 and 18,000 Btu/hr environmental control units (ECUs). This model suggests a highly variable heat load throughout a standard hot-dry day that can vary by a factor of 20 from the lowest to highest thermal load. This scenario is ideal for load shifting and consumption reduction through thermal energy storage (TES). In this proposal, we propose an integration strategy and design methodology for a phase change material thermal energy storage (PCM-TES) add-on device for military ECUs. An hour-by-hour thermodynamic analysis is presented that demonstrates a daily energy consumption reduction of 9.0% for a 9k Btu/hr ECU, and 6.8% for an 18k Btu/hr ECU. In Phase I, Mainstream will design a PCM-TES device using already developed finite element design tools. Additionally, we will fabricate and test a partial-scale ECU system with an integrated PCM-TES device to validate energy saving performance. In Phase II, the device will be scaled up and integrated with a 9k ECU. Performance will be validated experimentally, and environmental testing will be performed. Phase III will focus on the development of volume manufacturing methods and additional product introductions for other ECU capacity variants.