Solution of Tribological Problems on a Compact Distribution Steam Valve for Capacity-Type Rankine Cycle Expansion Machines for an Automobile

Abstract

A compact-sized in-vehicle Rankine cycle that recovers exhaust heat with high efficiency and fuel economy has been developed. The system integrates a capacity-type compact expansion machine that uses high-pressure and high-temperature steam and a generator. The key component that determines the performance of the expansion machine is the distribution steam valve. The requirements for the valve to satisfy the performance are low leakage and low friction. However, it has been difficult to satisfy the requirements with the existing mechanisms and materials due to problems such as corrosion and lubricity. A valve has been designed that satisfies the requirements by letting water be retained on the surface of sintered carbon to improve wear resistance and, at the same time, by letting the valve surface dither during steam distribution to maintain the water. This is the report of the configuration and performance of the distribution steam valve for a Rankine cycle expansion machine.

KEY WORDS:

• Rankine Cycle
• Fuel Economy
• Steam Valve
• Expansion Machine
• Generator

Acknowledgments

Review led by Jim Netzel