EVS28KINTEX, Korea, May 3-6, 2015

Centrifugal Air Compressor for Fuel Cell Electric Vehicle

Kyungseok Cho1, Hyunsup Yang2 , Chiyong Park3

Changha Lee4·Chi Myung Kim51,2,3Halla Visteon Climate Control Corp., 95, Sinilseo-ro, Daedeok-gu, Daejeon, Korea

4,5 Hyundai Motor Group,17-5Mabuk-ro #240, Giheung-gu, Yongin-si,Gyeonggi-do, 446-716, Korea

Contents

I. Introduction1. Balance of Plant & Air Compressor 2. Selection of Air Compressor Type

II. Low Noise & High Performance Air Compressor1. Structure of Centrifugal Air Compressor2. Design Process of Air Compressor2. Design Process of Air Compressor3. Surge Margin improvement using CFD4. Rotor dynamic optimization techniques 5. Improvement of Structure Resonance6. Significant improvement in NVH performance

III. Conclusion

2

ExhaustExhaust

Air intakeAir intake

Air Provide SystemAir Provide System

Humidifier

Balance of Plant & Air Compressor

3

Water Pump

Thermal managementThermal managementRadiator

3-way Valve

H2 Tank

ExhaustExhaust

HydrogenHydrogenHydrogen SupplyHydrogen Supply

Fuel Cell Stack

Selection of Air Compressor Type

Ø Decision making - No oil mist*/High efficiency/Low noise & vibration/Low cost/Compact size

Type CentrifugalCentrifugal Displacement

Shape

* Oil mist contamination is a major cause of fuel cell degradation

4

Shape

Oil mist X O O

Efficiency High Even Low

Cost/Size Good Bad Bad

Vibration/Noise Good Bad Bad

BLDC Motor-Rotor

BLDC Motor-Stator

Centrifugal compressor- Impeller

Structure of Centrifugal Air Compressor

5

Inlet Duct

Centrifugal compressor- Volute

• Centrifugal compressor – compresses and pressurizes air, as per vehicle require• Brushless DC motor – converts electric energy into axial power for the compressor

Design Process of Air Compressor

[Aerodynamic Design] [Motor Design] [Power Electronics Simulation]

6

[Rotor Dynamic Analysis] [Mechanical Design & Structure Analysis] [Test Performance & Nosie]

Surge Margin improvement using CFD

[CFD Modeling & Analysis]

DecreaseAir flow loss

Inlet Air flowLoss

7

Stall

DecreasedUnstable air flow

[CFD Modeling & Analysis]

[Meridian Plane]

[Blade to Blade (span 0.9)]

Proto Sample

Improved Sample

Rotor dynamic optimization techniques

[Analysis Model]

Rigid 2nd mode

Rigid 1st mode

766Hz(46,000RPM)

8

[Critical Speed of Air Compressor]

[Rotor Structure]

ü Weight Reductionü Length Reductionü Increase Shaft Stiffness

Prototype Improved1st Mode 41,012RPM 45,672RPM

2nd Mode 89,000RPM 115,496RPM

[Critical Speed Map]

Improvement of Structure Resonance

9

[Vibration Characteristic at Volute]

[Impact Test Result at Rear Support]

Significant improvement in NVH performance

1X

3X

[Proto Sample Noise]

StructureResonance

10

[Test Bench & Setup for Noise Measurement][Improved Sample Noise]

[DER Noise Level in Vehicle][Noise Test in vehicle]

Conclusion

u Centrifugal type Air Compressor has advantage in- High Efficiency - Low Noise level

u Surge Margin improvement using CFD- Impeller Angle - Volute Development Angle

To meet MHG’s NVH level specifications, HVCC conduct

11

u To meet MHG’s NVH level specifications, HVCC conduct- High Speed Motor Electro-magnetic field optimization - Rotor dynamic optimization techniques - Improvement of Structure Resonance