Experimental Determination Of Convection Boiling Curves for Water
Experimental Determination Of Convection Boiling Curves for Water and Ethylene Glycol in a Rectangular Channel with Localized Heating By Andrew T. O’Neill 3 -23 -05
Topics of Discussion n n Introduction Experimental Apparatus Experimental Procedure Results Conclusion
Introduction n Background n n n Automotive Application Previous Research Objective n n Realistic Conditions Experimental Data
Experimental Apparatus n n Flow Loop Test Section Heater Instrumentation
Flow Loop
Flow Loop Control n n n Pressure Flow Rate Temperature
Flow Loop Instrumentation n Flow Rate n n Turbine Flow Meter Temperature n 3 TCs
Test Section
Heater Section
Test Section Instrumentation n Pressure n n 0 -100 psia 4 TCs n n E-type Embedded in Heater Element
Heater Element (Dimensions in mm)
Heater Thermocouples n 4 TCs n n 3 Along Surface 1 Pair n Surface Temp (Dimensions in mm) n Heat Flux
Heater Assembly
Data Acquisition n National Instruments n n n Lab. View Software PCI-MIO-16 E-4 Hardware SCXI Signal Conditioning n n 1102 Module, 1303 Breakout Box 1124 Module, 1325 Breakout Box
Data Acquisition Cont. n Measurements n n Flow Rate Temperature n n Bulk Fluid Heater Pressure Control n n Bulk Heating Heater Power
Assumptions n Steady State Condition n n 1 -D Heat Transfer in Copper Element Stabilized Surface Temp and Heat Flux Inlet Temp Used as Bulk Fluid Temp Fluid Pressure n Average of Upstream and Downstream Measurements
Experimental Uncertainty n Flow Rate / Velocity n n n System Pressure n n ± 1. 6°C Heater Temperature n n n ± 0. 017 atm + 0. 86% of reading Bulk Temperature n n ± 1. 9 lpm + 2% of reading ± 0. 05 m/s + 2% of reading ± 1. 5°C to actual ± 0. 18°C relative Heat Flux n ± 0. 142 W/cm 2 + 5% of reading
Experimental Procedure n Loop Filling n n Cleaning Evacuating Degassing Working Fluid Data Collection
Loop Filling n Cleaning n n Evacuating n n n Acetone Solvent Dual Stage Rotary Vane Vacuum Pump -5°C Cold Trap Degassing n n Pressure Vessel After Filling
Data Collection n Bulk Conditions Set n n Pressure Inlet Temperature Flow Rate Systematic Curve Development n n 1000 Samples/s 250 Samples/update 900 Updates After Heat Flux Change 100 Updates Recorded
Data Collection Cont.
Data Collection Cont. Bulk Conditions for Water Inlet Temperature 50ºC 70ºC 90ºC 100ºC 110ºC 0. 5 m/s 1. 00 atm, 1. 41 atm, 1. 97 atm, 2. 61 atm 1. 41 atm 1. 97 atm 1. 0 m/s 1. 00 atm, 1. 41 atm, 1. 97 atm 2. 0 m/s 1. 00 atm, 1. 41 atm, 1. 97 atm 3. 0 m/s 1. 00 atm 4. 0 m/s 1. 00 atm Mean Velocity
Data Collection Cont. Bulk Conditions for Ethylene Glycol Inlet Temperature 58. 8ºC 78. 8ºC 98. 8ºC 108. 8ºC 118. 8ºC 128. 8ºC 0. 5 m/s 1. 00 atm, 1. 34 atm, 1. 82 atm, 2. 45 atm 1. 34 atm 1. 82 atm 2. 45 atm 1. 0 m/s 1. 00 atm, 1. 34 atm, 1. 82 atm 2. 0 m/s 1. 00 atm, 1. 34 atm, 1. 82 atm 3. 0 m/s 1. 00 atm 4. 0 m/s 1. 00 atm Mean Velocity
Water Results n n Effect of Velocity Effect of Subcooling n n n Due to Bulk Temperature Due to System Pressure Effect of Pressure
Effect of Velocity
Effect of Velocity Boiling at 90°C, 1. 00 atm, and 0. 5 m/s Boiling at 90°C, 1. 00 atm, and 1. 0 m/s
Effect of Velocity Boiling at 90°C, 1. 00 atm, and 2. 0 m/s Boiling at 90°C, 1. 00 atm, and 3. 0 m/s
Effect of Subcooling
Effect of Subcooling
Effect of Subcooling
Effect of Subcooling Boiling at 90°C, 1. 00 atm, and 0. 5 m/s
Effect of Subcooling Boiling at 90°C, 1. 41 atm, and 0. 5 m/s
Effect of Subcooling Boiling at 90°C, 1. 97 atm, and 0. 5 m/s
Effect of Subcooling Boiling at 90°C, 2. 61 atm, and 0. 5 m/s
Effect of Pressure
Effect of Pressure Boiling at 90°C, 1. 00 atm, and 0. 5 m/s Boiling at 100°C, 1. 41 atm, and 0. 5 m/s
Effect of Pressure Boiling at 110°C, 1. 97 atm, and 0. 5 m/s Boiling at 120°C, 2. 61 atm, and 0. 5 m/s
Summary of Water Curves n Convergence of Boiling Curves n n Around 20°C Wall Superheat Independent of: n n Velocity Inlet Temperature Pressure Photographic Study n n Varied Boiling Behavior Same Heat Flux and Wall Superheat
Ethylene Glycol Results n n Effect of Velocity Effect of Subcooling n n n Due to Bulk Temperature Due to System Pressure Effect of Pressure
Effect of Velocity
Effect of Velocity Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 1. 00 atm Boiling of Glycol at 98. 8°C, 2. 0 m/s, and 1. 00 atm
Effect of Subcooling
Effect of Subcooling
Effect of Subcooling
Effect of Subcooling Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 1. 00 atm Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 1. 34 atm
Effect of Subcooling Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 1. 80 atm Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 2. 45 atm
Effect of Pressure
Effect of Pressure Boiling of Glycol at 98. 8°C, 0. 5 m/s, and 1. 00 atm Boiling of Glycol at 108. 8°C, 0. 5 m/s, and 1. 34 atm
Effect of Pressure Boiling of Glycol at 118. 8°C, 0. 5 m/s, and 1. 80 atm Boiling of Glycol at 128. 8°C, 0. 5 m/s, and 2. 45 atm
Summary of Glycol Curves n Boiling Heat Transfer n Independent of: n n Velocity Inlet Temperature Dependant on System Pressure Photographic Study n Similar Boiling Behavior with Varied Wall Superheat.
Comparison of Water to Glycol n n Similar Response to Velocity Increased Wall Superheat with Boiling Effect of System Pressure Effect of Subcooling n n n Constant System Pressure Constant Inlet Temperature Boiling Behavior at High Subcooling
Similar Response to Velocity & Increased Wall Superheat
Effect of System Pressure
Subcooling at Constant Pressure
Subcooling at Constant Inlet Temperature
Boiling Behavior at High Subcooling Boiling of Water at 90°C, 2. 61 atm, 0. 5 m/s, and 40°C Subcooling Boiling of Glycol at 98. 8°C, 2. 45 atm, 0. 5 m/s, and 40°C Subcooling
Conclusion n Experimental Apparatus Successfully Constructed n n Representative of Engine Cooling System Boiling Curves Developed for Water and Water Ethylene-Glycol Mixture n Showed Effects of: n n n Velocity Pressure Subcooling
Questions?
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