IMPROVED THERMAL VACUUM CHAMBER TEMPERATURE PERFORMANCE VIA GASEOUS NITROGEN THERMAL CONDITIONING UNITS

摘要

Many of today’s thermal vacuum test programs requireuniform and precise control over wide temperature rangeswhile minimizing operating budgets. These requirementshave driven interest in energy-efficient gaseous nitrogenThermal Conditioning Units (TCUs) for temperaturemanagement of shrouds and platens. Here we presentrecent innovations in TCU design for improved thermalperformance. Compared to mechanical refrigerationsystems, TCUs offer an increased temperature range (-180 C to 150 C) and negate the possibility of chambercontamination via shroud leaks. Gaseous nitrogenTCUs also provide better temperature stability, set pointcontrol, and significantly reduced steady state liquid nitrogenconsumption compared to flooded liquid nitrogenshroud systems. Furthermore, because nitrogen closelyadheres to the Ideal Gas Law, system modeling is relativelystraightforward and system performance is highlypredictable and stable. We will provide an overview ofTCU characteristics, give examples of successful applications,and compare and contrast shroud performance.Methods for appropriately sizing Gaseous Nitrogen ThermalConditioning Units will also be presented.