Calculate Vacuum efficiency of the condenser.

Question

The following observations refer to a surface condenser :

              Mass flow rate of condensate = 20 kg/min

              Mass flow rate of cooling water = 800 kg/min

              Mean temperature of condensation = 35⁰C

              Condenser vacuum = 0.95 kg/cm²

              Inlet cooling water temperature = 20 ⁰C

              Outlet cooling water temperature = 30 ⁰C

              Temperature of the hot well = 29 ⁰C

              Calculate :

1. Weight of air per unit volume of condenser.
2. Entering condition of steam to the condenser
3. Vacuum efficiency of the condenser.                                                                           25

 

Properties of saturated steam :

T (0C)	P (MPa)	Sp. Vol (m3/kg)		Enthalpy (kJ/kg)		Entropy (kJ/kg.K)
		vf	vg	hf	hg	sf	Sg
35	0.0056	0.001	25.245	146.56	2565.4	0.5049	8.3543

     

(Use R = 0.287 kJ/kg.K)