Parabolic Trough Prototype

Introduction

Gang Xiao, professor at University of Nice, France, has developed a low-cost parabolic trough solar thermal concentrator, applicable to electricity production. He is pursuing the steam engine as the heat engine of choice.

Factor e Farm is interested in evaluating the performance of this system by building a prototype. Here are the detailed instructions for prototype deployment.

This method http://www.ffwdm.com/solar/solar-index.htm for constructing parabolic arrays deserves consideration as well. Demonstrated cost of $150 for 800 watt sections in Toronto Canada. Note that the pipe serves as the rotational bearing surface, eliminating need for flexible pipe connections. (Warning: this last one probably has a temperature limite too low for efficient power generation. The lifetime may also be a problem.)

Bill of Materials

Estimation of the material cost for 1m² of collector. The costs are in dollars.

Use	Material	Specification	Quantity	Cost
Cover	tempered glass	5mm	1.05m2	?
Back and ends	steel sheet	0.5mm	1.6m2	?
Mirror	adhesive mirror film	-	1.6m2	12
Structural pieces	stainless steel bars and angles	width around 15mm	~15m	?
Bearings	metal tubes	φ40mm×20mm	2	2
Support	Plastic pieces	to be moulded	2	2?
Photodetector	photoresistors+case	-	1	2?
Controller + gear	commercially available	-	1	10-30
Receiver	metal tube	configurable	~1.2m	~5
Chassis	square steel tubes	30mm	~3m	5?

Structural pieces - what is the thickness, and how much of it is angle and how much of it is bar?

--- Roughly, half-half. About 1mm thick.

Can the support pieces be printed with RepRap if we have access to it?

--- Yes.

Can you show a picture and dimensions of the plastic pieces?

--That will come.

Specify photodetector and photoresistor, plus size of case

--- See my DIY document.

Where?--Dennis 09:04, 15 March 2009 (UTC)

Sorry: I didn't know how to insert links. manual making of parabolic trough Azuredu 10:33, 15 March 2009 (UTC)

One axis controller, and what about the control motor?

Show the angle tilt mechanism.

Diameter and wall thickness of collector tube?

--- These are interchangeable.

What about sealing of corners?

-- Don't seal. The design takes care that direct rain water won't get in. For cleaning water jets, some kind of protection with sponge foam will be enough. Azuredu 19:56, 13 March 2009 (UTC)

What about reflective coating?

--- Mylar film.

Any evidence or other examples of mylar being used for parabolics for solar concentrators?--Dennis 15:12, 12 March 2009 (UTC)

The best example is car headlights. This is not exactly mylar, but the technology is the same: a metal reflective coating protected by a plastic sheet cover. Otherwise, [Absolicon.com Absolicon.com] is selling troughs using silver-coted mylar mirrors, but the commercialization is still very limited. Here the point is that mylar must be protected from humidity, rain water and dust (or more exactly cleaning scratch).Azuredu 19:51, 13 March 2009 (UTC)

What about couplers for collector tube and inter-collector connection for stringing multiple collectors?

--- Ordinary (home water supply) tube connectors.

What about stand and base?

--- Rather free design.

Fabrication Procedure

manual making of parabolic trough