IT设备冷却中两相流沸腾的综合分析：系统和组件级方法.pdf

1、Trade-offs between single-phase and two-phase liquid coolingCoolIT Systems Inc.Trade-offs between single-phase and two-phase liquid coolingCOOLING ENVIRONMENTSReza Najjari,PhD,P.EngAdvanced Technology Manager CoolIT SystemsOutline54321RefrigerantsPressure dropPressure drop effectThermal resistance d

2、efinition Cooling loop design:series vs parallelEquipment sizingNext steps and call to actionFor study details see InterPACK2024:Comprehensive Analysis of Two-Phase Flow Boiling for IT Equipment Cooling:A System and Component-Level Approach Two-Phase Study Set-UpCoolITs bench-top 2P loop at Liquid L

3、abTMInnovation CenterRefrigerantsSystem PressureHigh-Sat PressureLow-Sat PressureWhole Cooling Loop is High-P200PSIColdplates are Thicker Certified to P 400-600 PSI1stStep(System Design)NOT Easily Swapable10 x to 12x More Expensive than PG25Higher CostSub Zero Condensing T if P10 PSIGWP vs Flammabil

4、ityRegulations Reducing GWP(R22,R134a,)System becomes Obsolete Leaks:Expensive Legal FinesPressure Drop Effect Pressure change affects saturation temperature.Pressure drop reduces saturation/condensation temperature.Coldplates,filters,QDs,manifolds,valves and condensers all cause pressure drop.Press

5、ure drop necessitates a lower primary side temperature.This is called Effective Thermal Resistance in a 2P DLC system.Pressure Drop Effect|EXAMPLE32 PSI P=a 8 C drop in the Saturation/Condensation Temperature.4545C C Saturation/Boiling at the coldplates 3737C C condensation T at the condenser.Preven

6、t cavitation in the pump sub-cool R134a by 5 5C C T Out of condenser=3232C C.An Approach Temperature of 5C=The primary loop coolant temperature to the condenser to be 2727C.C.Low pressure refrigerant(e.g.R1233zd)results in a 20 PSI pressure drop=3030C C drop in the saturation temperature.R134a 2P DL