A steam turbine at steady state is operated at part load by throttling the steam to a lower pressure before it enters the turbine. Before throttling, the pressure and temperature are, respectively, 2 MPa and 300°C. After throttling, the pressure is 1 MPa. At the turbine exit, the steam is at 8 KPa and a quality of 85%. Heat transfer with the surroundings and all kinetic and potential energy effects can be ignored. Determine (a) the temperature at the turbine inlet, in °C, and (b) the power developed by the turbine, in kJ/kg of steam flowing.

a) 440° C

b) 808.354 kJ/kg

Explanation:

Properties of 2.0 MPa and 300° C

= 3024.2 kJ/kg

= 6.7684 kJ/kg.K

Properties at 1 MPa and = 3024.2 kJ/kg

Using properties at 1MPa and from steam Table

= 440° C

At the turbine exit

the steam is at 8 KPa which is equivalent ⇒ 0.08 bar

Properties at 0.08 bar

= 173.84 kJ/kg

= 2402.36 kJ/kg

85% = 0.85

= (173.84+(0.85*2402.36)

= 2215.846  kJ/kg

P = (3024.2 - 2215.846) kJ/kg

P = 808.354 kJ/kg

i think the answer would be b

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.