FW: GAS-L: Wasted heat retrieval to electrical power

[Weststeijn A <A.Weststeijn@epz.nl>]

> Hi Peter,    ********Corrected version********
> 
(oophs, need to correct my temperature conversion Fahrenheit-Centigrade visa
versa and my related conclusion as to the highest potential S/H temperature
in degrees F)

1400 F = 760 C
1290 F = 700 C 
1250 F = 677 C
1110 F = 600 C
1080 F = 580 C

> Peter Singfield[SMTP:snkm@btl.net]
> maandag 19 februari 2001 1:00
> 
> Andries made a comment (probably off list) regarding 1250 F (677 C) being
> the
> practical upper limit for super heated steam --
> Andries -- take a look at:
> http://www.nedo.go.jp/3color-e/shinene/shoene-4.html
> 1300 to 1400 "C"
> 
> Peter, I commented on superheated steam temperatures in boilers. That's
> about steel.
A really quite high, but still realistic present day S/H steam condition is
1080 F (580 C). There might be an example found of 1110 F (600 C) somewhere,
but that's it.

> The link is on ceramic materials for GT's. Different ball game.
Ceramic materials are not really ment for supercritical pressure piping.

As to the S/H steam temperatures in boilers:
> You consistently continu to refer to 1400 F (= 760 C) as "normal" for
> boilers.
> I keep pointing out that this is an very advanced temperature condition.
> And certainly is not generally introduced state of the art.
> 
> There is an European R&D project going on -including large boiler and
> turbine manufacturers- with the aim of 700 Centigrade (1290 F) S/H life
> steam temperature for large boilers to be reached in about 2010-2015! May
> that tell you something.
> 
> Don't keep mentioning 1400 F (760 C) S/H steam as a piece of cake for
> boilers and turbines. It isn't.
> It's all about transition to austenitic steels, having to qualify from
> step 1 in this service, and making for very expensive materials.
> It is NOT the cheap and easy solution -simply copied from another
> application into boiler use- you are looking for.
> 
> From a different perspective:
> -Potential:
> If you use 1400 F (760 C) as the future POTENTIAL of the classic
> steam-water cycle as compared with the POTENTIAL for refrigerant cycles,
> there is no basis for this high a temperature yet, as I know off. With
> respect to future potential you could go up as high as 1290 F (700 C) due
> to work going on in Europe and Japan. I don't know about the US.
> -Price:
> The high costs of austinitic boiler tubes and life steam piping may give
> "cold" cycles (ran on refrigerant) more "financial room" to play with for
> break even. 
> -Efficiency:
> But the nett efficiency of these advanced steam-water cycles (thermal
> energy into electricity) is estimated to be around 50% and that will have
> to be met by these refrigerant cycles as well.
> 
> 
> best regards,
> Andries
>