Presentation for Design of Solar Thermal Dish Stirling 500 w, ISEC 2007.

1. Eng’r. Suravut, Snidvongs
ISEC 2007, Tokyo, Japan

2. Insolation in Thailand is varying between in 450 to 550 W/m2
daily whole year round, and the average value is at 550 W/m2
daily over the year.
To operate the Solar Dish Stirling with medium insolation the
system must design to operate with proper conditions, such as
increasing dish diameter, reduce power to track dish structure,
reduce piston and drive mechanism friction.
The rotary drive mechanism seems to be lower friction than
other mechanism such as gear drive, and whisper tech swash
plate system

3. Type Gamma
Acting Double
Driver Mechanism Negative Rotary
Working Gas Air
Expansion space Temp 650 C (+/- 5 C)
Compression space Temp 40 – 50 C (+/- 5 C)
Ambient Temperature 40 C (+/-5 C)
Thermal Efficiency 60 %
Power Control Variable Pressure
No. of Cylinders 4
Means Pressure 0.5 MPa
Maximum Pressure 1 Mpa
Power Piston Diameter, mm. 48
Stroke, mm. 40

4. Power Displacement, cc. 72 x 4
Displacer Diameter, mm. 42
Displacer Length, mm. 150
Heater surface area, cm2 11.40
Cooler surface area, cm2 29.12
Regenerator surface area, cm2 161.60
Expansion swept, cm3 340.00
Compression swept, cm3 220.80
Speed, rpm 500 – 1200
Regenerator Type Tube
Cooling type Ethyl glycol
Electric heater 220 V 700 x 4 W
Mechanical Output Power 215 W @ 20 psi
Mechanical Output Power 550 W @ 80 psi

5. Cost USD 1,280.00
Mean Time Between Fail (hrs) 18,000
Maintenance Time (hrs) 3,500
Torque (N-m) 10.4
Thermal Eff. % 60
Mechanical Eff. % 31

8. • As Rotary drum is well balance the vibration is lowest.
• Rotary Drive has fewer parts than other systems.
• Rotary Drive are very complicate and accurate to make.
• The cost of the system is medium high.
• The friction is about 6.1 W.
• The engine torque 10.4 N-m.
• Thermal efficiency is 60 %.
• Mechanical Efficiency is 31 %.
• The Rotary Drive Mechanism can be improved mechanical
efficiency up to 31 %.
• SSESIII required power to track only 10 x 2 W.
• By increasing dish diameter, reduce power to track, enlarge
displacer piston, reduce friction for drive mechanism, and
reduce power piston friction make the SSESIII operate with
Thailand conditions.