Bob Bourque - New Steam Engine

Chapter	Title
1	Background
2	Motivations For This Engine
3	Requirements and Constraints
4	Progress
5	Prototype Development
6	Description of the Bourque Cycle
7	Features of the Cycle
8	The Complexity Issue
9	Fuel Requirements
10	First Example Engine in a Vehicle
11	Description of the Expander
12	Expander Hot Cylinder Lubrication
13	Expander Piston Structural Analysis
14	Two More Engine and Vehicle Examples
15	Other Engine Components
16	Materials
17	Safety
18	Water Freezing
19	Control System
20	Starting Time
21	Summary
	Acknowledgments
	Some Unit Conversions
	Notes and References

A Compact Pollution-Free
External Combustion Engine
with High Part-Load Efficiency

16. Materials

These engines are intended to be mass-produced. Therefore materials used must be readily available, not difficult to fabricate, and reasonable in cost. Yet they must be capable of adequate strength at their operating temperature. Table 5 shows the primary materials used. The Time-at-Load is used to establish allowable stress using data in the ASME Codes [25].

For engines where fuel consumption issues override initial cost, such as large trucks and locomotives, more expensive materials with higher temperature capability could be used. However, the example truck engine shown above uses the materials in Table 5. Therefore, there is room for some efficiency improvement.

The Bourque Steam Engine

A Compact Pollution-Free External Combustion Engine with High Part-Load Efficiency

A Compact Pollution-Free
External Combustion Engine
with High Part-Load Efficiency