How does injecting water cool to a temp lower then the water itself?
- Thread starter yellow95
- Start date
latent heat of vaporization.. or something like that..
essentially it's refrigeration.. you take a liquid, you spray it through an orifice, and the pressure drop allows it to "boil off", essentially absorbing a mess load of heat. Same exact way the refirgerant in your A/C works, except that.. where water will maintain liquid form at a normal ambient temp and pressure.. refrigerant won't.. it has to be compressed in order to keep it a liquid.
The phase change is what pulls the heat out in essence.
Alky does the same thing, but can get a bit colder.. friends alky rail, likes to come back with the manifold sweating after his 180+ mph passes.. pretty cool really.. no pun intended..
day job is commercial refrigeration.. might have terms and things a lil mixed up.. it happens.. but the concept and meaning is true.
essentially it's refrigeration.. you take a liquid, you spray it through an orifice, and the pressure drop allows it to "boil off", essentially absorbing a mess load of heat. Same exact way the refirgerant in your A/C works, except that.. where water will maintain liquid form at a normal ambient temp and pressure.. refrigerant won't.. it has to be compressed in order to keep it a liquid.
The phase change is what pulls the heat out in essence.
Alky does the same thing, but can get a bit colder.. friends alky rail, likes to come back with the manifold sweating after his 180+ mph passes.. pretty cool really.. no pun intended..
day job is commercial refrigeration.. might have terms and things a lil mixed up.. it happens.. but the concept and meaning is true.
Water absorbs something like 4.184 J/G/degree celcius. So if you're injecting water @ 20 degrees celcius (approx. room temp) every gram of water could absorb 334.72 J of energy from the air untill it vapourizes, and water absorbs around 2260 J/G during the change from water into steam/water vapour. When you figure that air has a a specific heat capacity about 1/4 that of water, you can get an idea of why it can drop the temps so low. Keep in mind my numbers might be a little off, but those are as close as I can remember.
Its because of the low pressure.
When you inject water into an area of lower pressure (your KB inlet) the water vaporises much faster than it normally would at a higher pressure.
Since it vaporises so much faster it removes the heat in a shorter ammount of time. Thus your cold inlet pipe.
When you inject water into an area of lower pressure (your KB inlet) the water vaporises much faster than it normally would at a higher pressure.
Since it vaporises so much faster it removes the heat in a shorter ammount of time. Thus your cold inlet pipe.
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