Solar Reactor using water tubes & dish collector.

[BillThompson]

Hi,
The dish is roof mounted and fixed.
I want to heat water tubes coming from the base up to the focal point and I'm needing to know if this is sound or a tube coming from the base will never get enough focal point to heat it because it's fixed and not on a heliostat.

Or, does the water tube get enough solar radiation when not at focal point to heat it to boiling?
I'm using a tube bundle, a replacement part in heat exchangers. They come 24" to 120" long.
They have many tubes with each tube rated at 150PSI and 375F.
My plan is to use the water tube boiler design and run the water tubes through the solar dish receiver but up from the base, not suspending it.
This type of tube bundle has two sets of twin tubes that are U shaped and just basically go in and out. I planned to use one set of tubes for the water feed drum to the tube bundle and then to the steam drum boiler. The second set of tubes are feed from the steam boilers and run back through the tube bundle and I planned to use them as a superheater and then feed to a turbine. Then from the turbine to condenser back to feed drum.

My thoughts about problems.
The tubes are rated at 375F and the tubes may melt or fail from the high temperature heat at focal point.
The excess tubing may just defuse the heat energy.


The design is basically the solar hot water heater using a parabolic collector rather than a panel of tubes collecting solar radiance.

Any comments positive or negative are welcome.

 

[Unrest]

Sounds like you said, the dish would be no use without a heliostat. You could work out from geometry what range of sun positions would have the light reflected onto the tubes. Then you might get enough high temperature for few minutes a day. It sounds like your purpose is to generate power so you need high temperature in a small volume of water, rather than a lot of water at medium temperature?I have a conventional solar water heater that can go up to about 80degC in the summer. But only with some leftover hot water from the day before.

I wouldn't worry about the tubes overheating as long as they're always filled with liquid water. That'll keep their temperature to not much more than boiling point.