GAS-L: Fw: [energyresources] Low Heat solar tracker - addendum

["Kermit Schlansker" <kssustain@provide.net>]

>Dear Perry,
>
>        You complained off list that I did not answer your question. I
>prefer to answer on list because any post that conveys useful information
>should be published. There may be people on the lists who do not understand
Rankine systems. The use of waste heat applies to solar power, gasification,
and IC engine tailpipes.
>        One reason I didn't answer is that I am a 77 year old klutz and
>never do what I want to. The other answer is that your system didn't make
>sense to me.
>        I do not understand why anything must wobble if you are using an
air
>motor as an expander. You just keep the sun's rays enhanced by mirrors and
a
>tracker on the boiler. Then the fluid vaporizes, goes through the expander
>and generates power. The essential parts of a Rankine cycle are a boiler,
>expander connected to load, a high pressure liquid pump, and a condenser.
>The technology is well known.
>         Various kinds of expanders include rotary piston steam engines,
>free piston compressors, vane motors, serial radial turbines, scrolls, and
>multiple axial turbines. If you are describing a heat off and on system
that probably would be low efficiency.
>          The efficiency limit of a Rankine cycle is given by the equation
>(Thigh-Tlow)/Thigh, where Rankine or Kelvin units must be used. For a
boiler
>temp of 250deg F and a condenser temp of 90 degF. the limit efficiency is
>22 %. The good engineer tries to approach this limit and to get a higher
>temperature range.
>          Obviously there is more energy at higher temperatures but my
>original question related to the practicality of a cheap, efficent multiple
>axial blade turbine made from aluminum, plastics or other cheap materials.
>They do wonders these days on making cheap, complicated toys from plastics.
>If efficient, such a turbine would be valuable for using waste heat or
>compressed gases, from many processes. It also would make a good
refrigerant compressor. It is  better to use lower pressure refrigerants if
possible because they are easier to contain. Turbines handle large volumes
at low pressures better than pistons.
>       Using a thermodynamic chart for  butane as expandant, I came up with
the folowing numbers: boiler temp 250F, condenser temp 90F. Phigh 350 psi,
Plow 50 psi. Boiler density 5 lbs/cuft, condenser density.55 lbs/cuft
>Efficiency, 18%.  This is better than a solar voltaic and mirrors should be
cheaper than voltaics.. Pentane would be a good expandant for a higher
temperature
>    On another note, someone on the solar list, I believe David Wells, is
trying to use a scroll compressor as an expander. I don't think this is a
good idea because the scroll probably has a thermal short circuit. The
Unaflow steam engine principle is that cool exit steam does not go through
the head but rather through a side port. This enables the head to stay
warmer than the exit end and is more efficient. In both the long stroke
piston, and the axial multiple stage turbine, the gozintus is thermally
separated from the gozoutous.

        If I were going to try to make an experimental expander, I probaly
would try to use the crank and block from an old IC engine. In a bigger
system the VW bug block would be good because the cylinders are separable.
In a smaller system you could use a lawnmower engine by mounting a new steam
cylinder on top of the old one.

                                    Kermit Schlansker
>-----Original Message-----
>From: Perry Arnett <pjarnett@pdqnet.net>
>To: energyresources@yahoogroups.com <energyresources@yahoogroups.com>
>Date: Monday, January 14, 2002 12:47 PM
>Subject: Re: [energyresources] Low Heat solar tracker - addendum
>
>
>>the first application might probably be its use as a solar water pump
>(there are others) i.e.
>>
>>connect the output to a wobble plate and a down hole pump, and even if the
>quantity drawn was only 1/2 a cup per stroke, in a
>>month, day after day, one could fill a cistern from which one could draw
>water in a controlled manner.  only works during the
>>day, when the sun is shining, but so what?
>>
>>for Newton, and Tulkin and others, I AM pro-solar - only because I am
>pro-ANYthing 'that works'.
>>
>>this will work
>>
>>so - now that I've given away the technology free - all those who are
>clamoring for 'solutions' - any takers?
>>
>>Perry in Utah
>>
>>
>>----- Original Message -----
>>From: "Perry Arnett" <pjarnett@pdqnet.net>
>>To: <energyresources@yahoogroups.com>
>>Sent: Monday, January 14, 2002 09:08
>>Subject: Re: [energyresources] Heat
>>
>>
>>> > which suggests that an 'engine' that uses solar heat to create
>mechanical motion CAN be justified, even if  not very
>>> > powerful',  - if the heat source is free and the operating cost is
>'almost' free.
>>> >
>>> > [I'm ready to divulge but I hear no takers...yet]
>>> >
>>> > Perry in Utah
>>>
>>>
>>> Kermit -
>>>
>>>  to put this to bed, consider this :
>>>
>>> take a freon charged solar tracker
>>>
>>> run the freon lines to a double acting hydraulic cylinder connected to
>either a linear air motor or a rotary air motor
>>>
>>> purposefully 'de-tune' the tracker shades so that rather than smoothly
>tracking the sun across the sky (as is the normal
>>case),
>>> it oscillates in a repetetitive, controlled, but back-and-forth manner;
>these oscillations can be large or small as one might
>>> find works the best for the purpose
>>>
>>> i.e. purposefully cause the tracker to 'hunt' for the sun rather than
>lock on and follow smoothly
>>>
>>> the action of 'hunting' will cause the tracker to generate 'surplus'
>mechanical motion, motion normally unwanted in solar
>>> trackers, but in THIS specific case, purposefully engineered to satify
>Kermits request, this motion is desired.
>>>
>>> how 'efficient'? quite, once constructed
>>>
>>> how powerful? determined only by the size of  the freon reservoirs, the
>operating pressure, the size of the hydraulic
>>cylinders
>>> and the rotary air motor
>>>
>>> how long lasting? VERY, once built
>>>
>>> operating cost? VERY low
>>>
>>> how useful? you imagine all the things you can do with a source of VERY
>low cost motion generated from a "low temp heat
>>> source"...
>>>
>>> how costly ? I can do a demo model  for ~$2500
>>>
>>> now - any takers?
>>>
>>> Perry in Utah
>>>
>>>
>>>
>>> Your message didn't show up on the list? Complaints or compliments?
>>> Drop me (Tom Robertson) a note at t1r@bellatlantic.net
>>>
>>> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>>>
>>>
>>
>>
>>
>>Your message didn't show up on the list? Complaints or compliments?
>>Drop me (Tom Robertson) a note at t1r@bellatlantic.net
>>
>>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>>
>


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