Cal Poly, Solar Thermal Electric Generator - Project Update: 4-20-09

The Suns of Power design team from California Polytechnic State University, Mechanical Engineering Department, senior project: design, analyze, build, test and operate a solar thermal electric generator that is capable of producing at least 200 W of usable electricity over the course of 1 hour.

As of April 19th, 2009, the system is almost completed. In this video we are hooking up the final components. We are testing the flowmeter, pressure gauges, thermocouples, pump, steam separator and various other components.

Here's how the cycle works:
Water is pumped through the collection pipe (11' painted stainless steel, enclosed by a 10' shot glass tube) located at the focal point of the mirror. When the mirror is focused at the sun, the water is boiled into steam. The steam leaves the collection pipe and flows into a steam separator. The steam flows through the top line of the separator, while any condensate drains through the bottom of the separator. In the steam line (on the top side of the cart), the steam travels through a needle valve that is used for throttling the steam engine. Also on this line is a pressure gauge and a displacement lubricator. Steam enters the lubricator and condensates. The condensate falls to the bottom and displaces the steam engine piston oil into the steam line. The steam then reaches that steam engine. The flywheel will soon be connected to a DC motor used as a generator. The steam then exits the steam engine through a check valve and meets up with the condensate that flowed down through the separator. This condensate/steam mixture is pumped up to a fin-fan heat exchanger that acts as the condenser. The condensed steam line connects to an expansion tank.. The expansion tank acts as a fill point for the system, allows thermal expansion of the water, sets the condenser pressure to atmospheric and provides the pump's required Net Positive Suction Head to eliminate cavitation in the pump. The water then flows down through a 5-micron, high temperature water filter and then to the micro magnetic driven gear pump. There is a thermocouple on the suction side, as well as pressure gauges at the suction and discharge. The flow rate of the water can be read off of the rotameter style flowmeter located directly after the pump. The water is then pumped underneath the mirror and then back through the collection pipe where the cycle begins again.

If you have any questions about our project, please email us or leave comments. We will respond as quickly as our busy schedules allow us. Thanks for watching!


(Music by The Learn-by-doings)

Category:

Science & Technology

Tags:

• Cal
• Poly
• solar
• thermal
• electric
• generator
• renewable
• green

[corymax10]

the steam wheel didnt turn? this big deal all for nothing? what you calculated the 200W by paper but not by actually developing the power? whoever your financer was lost money. you needed to capture the steam release from that pipe. fully enclosing the transfer is the answer???? hello

[CaptScruffywhiskers]

That was interesting guys,I must admit I'm curious to know why the recip engine and not a turbine.Auto salvage yards are a good source of turbo chargers.HP steam is more efficient and there are less moving parts.....Cheers!

[Georgieporgie1]

I think these kids are doing an experiment on music mixed with drugs from the Santa Cruz area

[soulsearcher009]

Extremely nice execution. It would be nice to see some real innovation however. Trough collectors and sterling engines could certainly be improved on. It's all about the money, I know. As for the friendly competition, go Mustangs eh. :)

[GeoffdeRuiter]

I would love to start a friendly competition with your University and mine (University of Victoria, BC) to see who could make the best producing and low cost system available for a small scale application! I have loved watching your progress and can't wait to see what kind of output you generate :)

[jonplaya13]

We're so close! Thanks for posting the vid lil' Wiz