Termodynamics - help with homework

[peterv6i]

Hello to all..

I have some homework to do but I haven't good thermodynamics background experience...

 

The "translated homework is"..

 

The compressor has a gass mas flow of 45 kg/min. on the entrance the specific enthalpy is 46 kJ/kg. On the exhaust the enthalpy is of 175 kJ/kg. Heat "dispersion" into the environment is 105 kJ/min.

Define the engine power if the effiency is 75%...

 

 

From this i have first defined the variables

h1 = 46 kJ/kg

h2= 175 kJ/kg

Qod = 105 kJ/min = 0,75 kg/s ??

eff = 75% = 0,75

m= 45 kg/min = 0,75 kg/s ??

 

On some internet pages i have found that

Power = m * (h2 - h1)

and

eff = P/Psteam

 

Please let me know

1.) If the units are in correct format

2.) Where to find some tutorial which covers my problem (above)

3.) Give me some direction on how to solve this hw..

 

thank you

Edited June 29, 2014 by peterv6i