[RE-wrenches] Gen preheat in cold climates

[Larry]

Hi Chris,

LP will boil (vaporize) at -44° so until your ambient temperature is 
below that it is vaporizing. Heating the tank will increase the liquid 
and vapor pressure in the tank but it is still liquid, not vapor, that 
is plumbed to a cold regulator, or vaporizer if they have one, where the 
vaporization takes place for the engine. I can't see that increase tank 
temperature would solve the issue.

In 1981 I bought a truck with dual fuel capability. The J-valve 
regulator had liquid heater lines from the coolant system to heat the LP 
liquid at the point of vaporization. The tank was in the bed and never 
heated. In very cold weather I had to start the engine on gas then 
switch to LP after hot water hit the regulator. All worked well with a 
warm regulator.

Larry

On 4/3/15 10:56 AM, Chris Mason wrote:
> Heating the regulator won't help if the propane is not vapourizing. 
> You would need to heat the tank.
> However, you do not need to heat it very much, just enough to let it 
> vapourize. Think about putting it somewhere with a little heat, or 
> burying it.
>
> On Fri, Apr 3, 2015 at 1:51 PM, Larry <larry at starlightsolar.com 
> <mailto:larry at starlightsolar.com>> wrote:
>
>     About the carb heat idea...LP is a liquid at -44°F. The liquid
>     does not combust, it must be vaporized. As the ambient temperature
>     drops closer to the LP liquid temperature, there would be a
>     reduction in how fast liquid is vaporizing and therefor a
>     reduction in volume. What you need in cold weather is enough
>     volume to maintain at least 11" wc while cranking or running the
>     engine. You can test the vapor pressure with a manometer while
>     cranking to verify if this is the problem.
>
>     If this is the reason the engine does not run, my thoughts are
>     that heating the LP regulator would be much more economical from
>     an energy standpoint, than heating the whole engine block. Perhaps
>     an insulated enclosure with silicone heaters appropriately
>     attached would work. They are available in many DC or AC and at
>     various voltages.
>
>     Larry Crutcher
>     Starlight Solar Power Systems
>
>

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