Engineering, 23.04.2020 22:49 cheervolley

One kilogram of water contained in a piston–cylinder assembly, initially saturated vapor at 460 kPa, is condensed at constant pressure to saturated liquid. Consider an enlarged system consisting of the water and enough of the nearby surroundings that heat transfer occurs only at the ambient temperature of 25 C. Assume the state of the nearby surroundings does not change during the process, and ignore kinetic and potential energy effects. For the enlarged system, determine the heat transfer, in kJ, and the entropy production, in kJ/K.

Answers

Answer from: shayla3613

$Q = 2118.075\,kJ$ , $S_{gen} = 2.0836\,\frac{kJ}{K}$

Explanation:

The process is modelled after the First and Second Law of Thermodynamic:

$-Q + m\cdot P\cdot (\nu_{1} - \nu_{2}) = m\cdot (u_{2}-u_{1})$

$-\frac{Q}{T_{surr}} + S_{gen} = m\cdot (s_{2}-s_{1})$

The properties of the fluid are obtained from steam tables:

Inlet

$\nu = 0.40610\,\frac{m^{3}}{kg}$

$u = 2557.8\,\frac{kJ}{kg}$

$s = 6.8490\,\frac{kJ}{kg\cdot K}$

Outlet

$\nu = 0.001089\,\frac{m^{3}}{kg}$

$u = 626.03\,\frac{kJ}{kg}$

$s = 1.8285\,\frac{kJ}{kg\cdot K}$

The heat transfer is:

$Q = m\cdot [P\cdot (\nu_{1}-\nu_{2})+(u_{1}-u_{2})]$

$Q = (1\,kg)\cdot \left[(460\,kPa)\cdot \left(0.40610\,\frac{m^{3}}{kg} - 0.001089\,\frac{m^{3}}{kg} \right) + \left(2557.8\,\frac{kJ}{kg} - 626.03\,\frac{kJ}{kg} \right)\right]$

$Q = 2118.075\,kJ$

Lastly, the entropy production is:

$S_{gen} = \frac{Q}{T_{surr}} + m\cdot (s_{2}-s_{1})$

$S_{gen} = \frac{2118.075\,kJ}{298.15\,K} + (1\,kg)\cdot \left(1.8285\,\frac{kJ}{kg\cdot K}-6.8490\,\frac{kJ}{kg\cdot K} \right)$

$S_{gen} = 2.0836\,\frac{kJ}{K}$

Answer from: Quest

Do you need to draw this out?

Answer from: Quest

it was a fall down when it happens

explanation:

Other questions on the subject: Engineering

Engineering, 03.07.2019 14:10, volleyballfun24

If the thermal strain developed in polyimide film during deposition is given as 0.0044. assume room temperature is kept at 17.3 c, and thermal coefficient of expansion for the film and the substrate are 54 x 10^-6c^-1 and 3.3 x 10^-6c^-1respectively. calculate the deposition temperature.

Answers: 3

continue

Engineering, 04.07.2019 18:10, meganwintergirl

Afour cylinder four-stroke in-line engine has a stroke of 160mm, connecting rod length of 150mm, a reciprocating mass of 3kg and its firing order is 1-3-4-2. the spacing between cylinders is 100mm. i. show that the engine is in balance with regard to the primary inertia forces and primary 3. a and secondary inertia couples. li determine the out of balance secondary inertia force ii. propose ways of balancing this out of balance force and discuss the challenges that will arise

Answers: 3

continue

Engineering, 04.07.2019 18:20, rjone8429

Asimple rankine cycle uses water as the working fluid. the water enters the turbine at 10 mpa and 480c while the condenser operates at 6 kpa. if the turbine has an isentropic efficiency of 80 percent while the pump has an isentropic efficiency of 70 percent determine the thermal efficiency

Answers: 1

continue

Engineering, 04.07.2019 19:10, nida7864

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed

Answers: 3

continue

You know the right answer?

One kilogram of water contained in a piston–cylinder assembly, initially saturated vapor at 460 kPa,...