What is adiabatic heat drop?

In an adiabatic nozzle, there is no “heat drop,” there is a TEMPERATURE drop,

associated with the conversion of internal energy to kinetic energy.

Adiabatic is happening without addition or misfortune of heat. The point when a gas is layered under adiabatic conditions, its pressure increments and its temperature climbs without the increase or misfortune of any hotness. Alternately, when a gas grows under adiabatic conditions, its force and temperature both diminish without the increase or misfortune of hotness. The adiabatic cooling of air as it ascents in the climate is the fundamental explanation for mist development. In adiabatic process heat is neither added nor removed from the system. So the work done by the system in adiabatic process will result in reduce of internal energy of that system. As internal energy is directly proportional to the change in heat there will be heat drop in an adiabatic process.

It might be better to give you a real world example of this.

In the old days (‘s+) they used to liquidfy air by compressing the air to about atm of pressure, let it cool to ambient temperature and then expand the air thru a Joule Thompson throttling valve fed to a counter flowing heat exchanger.

This produced a drop in temperature thru the J-T valve of approximately .C per atm. or about a centigrade drop . This air was fed back thru the heat exchanger and J-T valve over and over until it reached low enough temperature to liquidfy the air.

SO you see it was done with special purpose high pressure air compressors, lots of heat exchanging and counter flows and all this because regular expansion of air only drops / degree C with every atm of pressure.

Then along came an engineer named Georges Claude, who decided to use another process involving adiabatic expansion. His reasoning was that if you make the compressed air do some work, that the removal of the heat energy (internal energy) , that the drop in temperature should be much more than a simple throttling valve that lets all that compressed energy escape doing nothing.

The experiment worked too good. He used a old air compressor engine to run in reverse to be the expansion engine and put a brake on it to absorb the energy of the compressed gas and he fed air into the adiabatic expansion engine at atm pressure, and with him using atm as opposed to atm, he got a C drop in temperature with only a atm starting pressure.

The adiabatic expansion of the compressed gas and making it do work, takes all the internal energy out of the compressed gas. So total heat, Q , is only reduced by the loss of internal energy that resided within the contained compressed gas, and no work was DONE ON the system, but instead it was work done BY the system, which resulted in a giant heat loss only because of the work done in the adiabatic expansion causing the adiabatic heat drop

Q = ΔU + PΔV since in this case Q=ΔH

Heat engines and cryogenic engines all rely on the internal energy held within their hot or compressed gases. This internal energy comes from within the cylinder or boiler and no external source of energy. When you compress steam into a chamber, no further heat is added to that steam when it is ready to do work. The steam is aimed toward the rotor vanes which absorb the energy of the expanding steam. The more the vanes absorb the energy, the greater the loss of the internal energy of the steam and the greater the adiabatic heat drop of that steam.

In a % efficient steam turbine, the vanes would capture every bit of that steam’s internal energy in expansion and the steam would drop all the way to ambient temperature.

complex aspect. do a search onto yahoo. it can help!