FUEL AND AIR SUPPLY SYSTEM FOR COMBUSTION BASED POWER SOURCES

Speaker : C.M LeeTeacher : Cheng-Hsien Liu Date: 2007.6.6

TRANSDUCERS 05, Seoul, Korea, June 5-9, 2005

Daisuke Satoh, Shuji Tanaka and Masayoshj EsashiDepartment of Nanomechanics, Tohoku University

Outline • Introduction • System and components• Simulation and Result • Conclusion

Introduction• Hydrocarbon fuels such as methanol and

butane have much larger chemical energy density than electric energy density in existing batteries• direct methanol fuel cell (DMFC)• polymer electrolyte fuel cell (PEFC)

• PEFC using hydrogen as a fuel has one order of magnitude higher power density compared to DMFCs

• But !hydrogen is problematic in storage.• reforming hydrocarbons, storing hydrogen in

metal hydride, high-pressure containers and carbon nanostmctures, and producing hydrogen from chemical hydrides

• In this study, we have developed a fuel and air supply system for a combustor in a micro fuel reformer.

Introduction

System and components• Fuel reforming system

• micro valve and an ejector.• The valve regulates pressurized fuel gas• the ejector supplies air with the fuel to the combustor• In this study, iso-butane is used as a fuel

System and components (Micro valve)

• Micro valve• largely-deformable corrugated diaphragm• two small electrostatic valves.

• Design goal• low electric power consumption• low pressure loss• normally-closed operation for pressurized

fuel.

• The corrugated diaphragm is actuated by the vapor pressure of liquid gas

• The pressure to actuate the corrugated diaphragm is controlled by two small electrostatic valves

Micro valve

• The ejector is composed of a nozzle, a mixing section and a diffuser.

System and components (Ejector)

Simulation and Result • primary pressure and entrainment ratio which

is defined as the ratio of the mass flow rate of the secondary flow to that of the primary flow.

Simulation and Result

Simulation and Result

Conclusion • This paper described an ejector and a micro

valve used in a fuel and air supply system for a micro combustor.

• The CFD simulation of the ejector was performed

• The pressure loss is as low as 11 Pa/sccm, and the electrostatic valve controlled butane with a pressure of 220 Wa at a driving voltage of 40 V.