First, this engine was set to a steam generator specially designed at Maeta Company. This engine worked very well by the biomass boiler steam.
At Fig.8 this Mini SSSE installed on a manned small EV (electric vehicle) is shown, the SSSE is supplied steam from a small marine type three drums model boiler at its left, and reject steam at car end.
The engine is heated from downside by a gas burner, and it drives motor generator at right of the car by chain and it charges electric battery set below the seat. Solar car type directs driving motor at rear wheel drives the car at 6 Km/h at maximum. This Mini SSSE EV car ran very well fastest at the 3rd Stirling Techno Rally race held at Nov. '99 in Tokyo.
About two-hour generation and charging of electricity by SSSE runs the car for half-hour same as conventional EV cars with battery.
The EV car experience has shown that this kind of SSSE engines fits very well to the EV hybrid vehicles and small ships, because constant running of the engine and boiler are quite suitable, against any load variation of cars and ship themselves, if battery is equipped for energy storage.
5. PROJECT OF 3KW SSSE FOR LAND TEST
Now, for one more higher step to the practical application, "3KW SSSE" project is going on, and the design of reciprocating parts of this engine itself were nearly completed, which have just same principle as the reciprocating parts of Fig. 1, and it has two-stage expansion type cylinders with two sets of PP, DP; H and RG. Steam is distributed by one long cylindrical rotary valve on the back of the engine.
The diameters of PP and DP are 92mm and 40mm, and their stroke are 60mm and 92mm for first and second stage at about 1000cc volume in total. Its design speed is 840 rpm.
The head heaters are bayonet types made of double tubes, and each heater has nine bayonets.
The pressure of injected steam is 0.9 Mpa (gauge) and it should be heated up to 550℃ at the head heaters. The consumption of the steam is planned less than 27 Kg/h, if leakage is small. Other type of valves than rotary valve will be tested for befter efficiency and less leakage and to get best timing.
At Fig.9, the general view of the proposed this 3KW SSSE system for land use is shown. At the furnace, biomass wood tips, solidified rice chaff and plastic tips, or their mixture will be burnt, as the future sustainable fuels. The style of the boiler of this figure will be a mono tubes one-through type steam generator with one steam and water separator. It will have a circular coil tube heated by rotating flue gas as cyclone. This model has no condenser.
6. CONCLUSION
As shown here, through many experiments with modified conventional hot air model Stirling engine, power increase very much by air or steam injection from the bottom of DP at appropriate timing, has been shown very well.
Also heating of each Stirling head heaters effects very well.
Then, small size mini SSSE was made and successfully tested by steam, then it was used as the main electricity generator engine of a small manned EV car, and it has proved that this SSSE engine fits very well to EV hybrid car and boats.
Then 3KW SSSE prototype engine system for land use is under construction now for up stage practical development.
These experiments and experiences have shown the following many good points of this SSSE Systems.
