Re: Stove testing? need help.

[Reedtb2@cs.com]

Peter and all:

Pete's message about turndown should be important to all of us.  Most 
woodstoves have a VERY low turndown ratio - once burning, wood burns.  Our 
turbo stove is better - controlling the gasification air controls the gas 
produced, hence the heat.

But what is the turndown for kerosene, and what are the emissions at the low 
rate?

TOM REED

In a message dated 1/19/01 5:13:53 AM Mountain Standard Time, 
verhaarp@janus.cqu.edu.au writes:


> Years ago at the Eindhoven Woodburning Stove Group we tested a large number 
> of kerosene cookstoves.
> For cooking (boiling) you need a power rating appropriate for the amount of 
> food cooked to bring the pan and its contents quickly to the boil.
> After that you need just enough heating power to keep the pan and its 
> contents at boiling point. This is the so-called simmering stage.
> To compare the stoves you weigh the stove, containing enough fuel for the 
> test, before lighting it.
> The stove is lit and a pan with a known mass of water of known temperature 
> is placed upon it. The stove is turned up to full power. As soon as the 
> water in the pan has reached boiling point, the stove is extinguished and 
> weighed.
> The pan is also weighed.
> The heat transfer efficiency = (Mws * (100 - ts)*Cw +(Mws - Mwe)*He)/((Mks 
> - Mke)*Bk)
>
> where:  Mws     mass of water at start
>          Mwe     mass of water at the end
>          ts      temperature of water at start in C
>          Cw      specific heat capacity of water
>          He      enthalpy  of evaporation of water
>          Mks     mass of stove at start
>          Mke     mass of stove at the end
>          Bk      heating value of kerosene.
>
> It tells us how much of the heat produced by burning the calculated amount 
> of fuel has been transferred to the pan and its contents. If I memory 
> serves, quite a number of the multi wick stoves we tested reached 50 %.
>
> During the simmering stage the stove should ideally be capable of burning 
> at such a low rate that the pan and its contents are just kept at boiling 
> point without producing any steam.
> In this regard it is important that the stove can be turned down 
> sufficiently.
>
> Peter Verhaart