Dear Frank You are right about the 2676 but remember that the heat taken to evaporate water AT 0 deg is only 2501. I have questioned the difference in the past but forgot the reason.
HHV calcs may use that number (?) but I think it is cooled to 20 not 0. You can check. Here is a question for you: if the local boiling point is 95 deg C, what is the local latent heat of evaporation? Regards Crispin jumping in Jakarta -----Original Message----- From: "Frank Shields" <[email protected]> Date: Mon, 15 Oct 2012 09:04:58 To: <[email protected]>; 'Discussion of biomass cooking stoves'<[email protected]> Subject: RE: [Stoves] Energy calcs. Dear Crispin, So its 2676 (enthalpy vapor @100c) - 419 liquid at 100c = 2257. I get confused when there is no 'liquid' water as the H is in the wood structure. I realize all this in 'real world' differs with site specific. I will use the 2257 value and thank you all (again) for reviewing this. Seems if I leave it for a year I need to start over in understanding it. Thanks Frank -----Original Message----- From: Stoves [mailto:[email protected]] On Behalf Of Crispin Pemberton-Pigott Sent: Sunday, October 14, 2012 4:33 PM To: Stoves Subject: Re: [Stoves] Energy calcs. Frank, that water vapour number must be relative to some normative temperature. It doesn't match the usual numbers. It it was relative to condensed water at 100 C it would be 2257. If relative to water at 0 C it would be 2501. 486 g x 2257 = the latent heat of condensation which is what I would subtract from the HHV (bomb calorimeter). It is not absolutely correct but that is what people have agreed to do. For almost all biomass the deduction per dry kg will be 1.32 MJ per dry ash-free kilogram. Regards Crispin in the perpetual summer of Singapore -----Original Message----- From: "Frank Shields" <[email protected]> Sender: "Stoves" <[email protected]> Date: Sun, 14 Oct 2012 12:58:58 To: 'Discussion of biomass cooking stoves'<[email protected]> Reply-To: Discussion of biomass cooking stoves <[email protected]> Subject: [Stoves] Energy calcs. _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists .org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists .org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/
