ARC E-Newsletter 10.16.20: TARP-V: Optimizing Heat Transfer Efficiency

12 views
Skip to first unread message

Aprovecho Research Center

unread,
Oct 16, 2020, 2:49:30 PM10/16/20
to Aprovecho Research Center eNewsletter
E-news from Aprovecho Research Center

TARP-V: Optimizing heat transfer efficiency

Cartoon drawing of a sad cooking pot and a happy cooking pot

Mind the gap! 

Here are the TLUD (Top-Lit Up Draft Stove) derived heat transfer principles that ARC designers use when designing and improving stoves. They are just as important for Rocket stoves as TLUDs: 

 T: The temperature of the hot gas contacting the pot or griddle should be as hot as possible. 

A: Expose as much of the surface area of the pot or griddle to the hot gases as practical. 

R: Increasing heat transfer by radiation is important. Move the zone of combustion as close to the surface to be heated without increasing harmful emissions. 

P: Optimize the proximity of the hot gases to the pot or griddle by reducing the channel gap without reducing the velocity of the gases. Reduce the thermal resistance with appropriately sized channel gaps under and at the sides of the pot. Match the firepower to the channel gap size and to the size of the pot or griddle. 

V: In convective heat transfer, the primary resistance is in the surface boundary layer of very slowly moving gas immediately adjacent to a wall. Increase the velocity of the hot gas as it flows past the pot without reducing the temperature of the gases. As a rule of thumb, heat transfer efficiency can double when the velocity of the hot gases also doubles (N. MacCarty et al., 2015).

Find archived newsletters online at aprovecho.org/newsletters
© 2020 Aprovecho Research Center/Advanced Studies in Appropriate Technology
76132 Blue Mountain School Road, PO Box 1175, Cottage Grove, Oregon, 97424 - USA
(541) 767-0287www.aprovecho.org
Reply all
Reply to author
Forward
0 new messages