LED Back Light Cooling for Display Back of Display Display Heat - PowerPoint PPT Presentation

LED Back Light Cooling for Display Back of Display Display Heat Pipe Heat Sink LED Back view of Meter Panel Front view of Meter Panel Thermal performance Plate Heat dissipation 10W Fin (Attached LED) LED temp. < 90oC at ambient 65oC under natural convection condition Advantage 1) Silent (no fan) 2) High reliability (no fan) Heat Pipe Heat Pipe Heat Sink 1

LED Head Lamp Cooling Heat sink Frame LED Head Lamp Heat pipe (heat dissipation to frame) Thermal performance Heat dissipation 15W LED temp. < 90oC at ambient 40oC under natural convection condition Advantage 1) High performance 2) High reliability (no fan) 2

LRU Cooling in Aircraft Cooling concept Cooling concept LRU unit example development example 1 development example 2 LRU module Heat pipe Electronic boards Heat pipe Heat sink Air flow by use airplane air cooling system or in-built fan  Remote heat exchanger. Heat pipe transfer heat to heat  Heat pipe transfer heat exchanger outside of box. to chassis for cooling Cooling concept development example 3 Advantages:  Passive cooling, no moving parts, reliable. Individual LRU packed in cabinet  Higher heat transfer.  Robust design, low form factor. Heat sink Heat pipe 3

Cooling of Power Semiconductor- Smart Grid DC/DC Inverter for Motor Speed Control Cooling IGBT Cover Silicon gel (optional) IGBT Die (0.2mm Thk) Solder (0.15mm Thk.) Casing Cold Plate Copper(0.3mm Thk.) Ceramic (0.6mm Thk.) Copper(0.3mm Thk.) Solder (0.15mm Thk.) Vapor Chamber Base (4mm Thk.) 4

Air Cooled Heat Pipe Heat Sink for IGBT 700 400 510 Base: A1100, 700 x 330 x 20mm Fin: A1100, 700 x 150 x 0.5mm, Pitch 9mm, 51pcs Heat Pipe: D15.88 x 19pcs Cross-section of HP 5

IGBT and Semiconductor Power Devices Examples of some heat sinks for semiconductor power device Heat pipe with ceramic insulator joints for cooling high power (kW) thyristor. Metal saw machining technology can produce any size and shape heat sinks. 6

Vapour Chamber 7

Vapor Chamber Heat Sinks for Server For Blade Server Fins For Blade Server Copper-Water Vapor Chamber Vapor Two Captive Hardware dimensional CPU TIM Substrate heat flow MCM 1 KW Vapor Chamber Vapor Chamber for 2U-4U Server 8

Vapour Chamber + Heat Pipes for Graphic Chip Fins Heat Pipe Heat Out Copper Fins Heat Pipes Heat In Vapor Chamber Vapor Flow Liquid Flow Thermal performance of Vapour Chamber + Heat Pipes 0.300 0.280 0.260 Vapor Chamber Base Rca [oC/W] 0.240 0.220 250W GPU 0.200 0.180 0.160 20 25 30 35 40 45 Air Flow [CFM] Design VC+HP (Test Results) Design VC+HP (Calculation) Solid Base (Calculation) 9

Ultra Thin Vapour Chamber  Ultra thin  High heat dissipation capability

Loop Heat Pipe 11

Loop Heat Pipe: Concept Vapour channel Operating Principle (grooved portion) 1 Wick Evaporation Evaporator (grooved 2 Heat transfer by vapour Heat input tube) Liquid 3 Condensation 1 reservoir 4 Liquid transport by capillary effect Vapour Wick Container Wick channel Evaporator Condenser 2 4 3 Vapour Vapour line 1 Liquid line Liquid Flow 4 Liquid Flow Condenser Heat Sink Heat Source Heat output 3 12 Distinguishing features: Loop Heat Pipe Advantages: ① Porous structure only in evaporator ① High heat flux capability ② Long distance heat transfer ② Transport lines made from bare tube ③ Orientation independent operation ③ Separated liquid & vapour flow

Loop Heat Pipe Design and Working Evaporator + compensation chamber (liquid reservoir) Liquid line Vapour line Vapour flow channels Wick Liquid reservoir Condenser (different configurations possible) Bayonet tube (for uniform liquid Vapour Liquid flow distribution inside wick core) flow

Why Loop Heat Pipe ?  No leakage issues (safe  High heat transfer system) capability  No moving parts (reliable  Longer distance heat & powerless system) transport  Smaller system volume  Orientation (two phase system) independent operation  High system performance at high heat loads 14

Loop Heat Pipe: Application Areas 15

Vehicle Thermal Management Vehicles Ground Transport: Automotive Air Transport: Aircraft Challenges Objectives  High heat load  Thermal Control (Cooling/Heating)  Long distance heat transport  Energy Conservation  Variable Orientation  Acceleration & Vibrations Issues  Multiple heat sources 16

Aviation Applications 1 LRU CPC Rack Thermal control: Cooling Interior Exterior 3 2 Wing Anti Icing Engine Anti Icing DM-Fuel Cell Cooling Galley Heating Thermal control: Heating Co-generation (Power + Heat) System

LHP-DMFC Cogeneration System Fuel cell LHP stack ack Evapo porat ator or Fuel supply Air in Fuel in syste tem Elect ctric c ~ By-product By products s out Output utput Air out Water > 1 m purifier Vapour ur chamber amber or Liquid d line heat at sprea eade der with h heat at pipes s Vapour ur line Portab able e water er Load d cabine net (Gal alley ey ) Specifications:  Large scale  Heat load: 0.5 – 1 kW Hot t wate ter r Heat t exch changer Out  Distance: > 1 m Cold ld LHP wate ter In Conden enser ser 18

Existing Anti Icing System Heat required: 5.75 kW/m Internal swirl Wing size: Hot air bled B737 (Small plane): 9 m from the engine B777(large plane): 20 m compressor Air exhausted 19 Engine Anti Icing

LHP based Ice Protection System Specifications:  Large scale  Heat load: 0.5 – 1 kW vapour from Liquid line  Distance: > 1 m evaporator Leading edge Liquid to evaporator Leading edge Gravity Liquid Vapour LHP System line lines Heat transfer distance: 5 m Vapour line Loop heat pipe 510 mm 45 mm condenser 175 mm Condenser details Liquid reservoir 20 LHP Evaporator Q = 2 x 6.9 = 13.7 kW

CPC Rack Cooling Condenser plate Liquid line Heat 150 mm spreader Evaporator 10 mm Vapour line From vapour Specifications: Nickel or Titanium wick line  Small scale Tube connector  Heat load: 30 – 50 W  Distance: 100- 150 mm Bayonet tube Heat spreader Liquid chamber From Charging liquid line line

Automotive Applications Battery Cooling  Heat load: 0.5 – 1 kW LED Headlamp Cooling  Distance: 0.25 – 1 m  Heat load: 25 – 50 W  Distance: > 150 – 250 mm Battery Stack Spreader Heat plate Pipes LHP LHP Condenser Evaporator Loop heat pipe prototype Loop heat pipe prototypes 22

Loop Heat Pipe Prototype Evaporator 1000 mm 250 mm Vapour line Liquid line Grooved evaporator portion Condenser Ungrooved Nickel wick CC section Copper tube Wick installed Evaporator Internal inside Details Nickel wick with copper evaporator tube 23 evaporator

Cylindrical Evaporator: Performance Results Variable Constant conductance conductance  Horizontal heat mode  50% charge ratio  Heated length: 55mm (20 W/cm2)  Copper-water LHP with Nickel wick 0.13 0.11 24

Orientation Tests 100 Evaporator Temperature, ° C/W Top heat mode 1 m 90 80 0.5 m 70 60 0.25 m 50 40 Horizontal heat mode 0 100 200 300 400 500 600 Heat Load, W 2.5 Total Thermal Resistance, ° C/W 0.5 m Loop heat pipe was THM 0.25 m able to transfer > 500 2.0 THM W at any orientation 1.5 with heat source 1 m temperature < 100 º C THM 1.0 Horizontal 0.5 HM 0.0 0 100 200 300 400 500 600 Heat Load, W 25