A piston–cylinder device with a set of stops initially contains 0.6 kg of steam at 1.0 MPa and 400°C. The location of the stops corresponds to 40 percent of the initial volume. Now the steam is cooled. Determine the compression work if the final state is (a) 1.0 MPa and 250°C and (b) 500 kPa. (c) Also determine the temperature at the final state in part (b).

1 answer
Question:

A piston–cylinder device with a set of stops initially contains 0.6 kg of steam at 1.0 MPa and 400°C. The location of the stops corresponds to 40 percent of the initial volume. Now the steam is cooled. Determine the compression work if the final state is (a) 1.0 MPa and 250°C and (b) 500 kPa. (c) Also determine the temperature at the final state in part (b).

Answers

Answer: (a) Compression work at the final state with a pressure of 1(MPa) is: 44.32(KJ), (b) Compression work at the final state with a pressure of 500(KPa): 110.37(KJ) and (c) temperaure of the final state in part b: T=151.83(°C).  Explanation: Remember that the substance is steam so it's water (H2O) and the initial conditions are [tex]P_{1} =1MPa, T_{1}=400^{0}C, m=0.6Kg[/tex] and[tex]v_{2} =0.4v_{1}[/tex] from a saturated water table and the initial conditions we can determine that the state phase is superheated (see Table 1 attached) because the [tex]T_{sat}=179.88^{0} C \leq T_{1}[/tex] from the table 1 we get:[tex]v_{1} =0.30661(m^{3}/Kg)[/tex]. Now we have second conditions as: [tex]P_{2}=1(MPa), T_{2}=250^{0}C[/tex] so from the same table we can see the state still superheated and we get[tex]v_{2}=0.23275(m^{3}/Kg)[/tex], knowing that it's a isobaric process we can find the compression's work as:[tex]W_{b}=m*P(v_{2}-v_{1})=0.6*1000*(0.23275-0.30661)=-44.32(KJ)[/tex] so the compressor's work is: 44.32(KJ). (b) Then the piston reaches the stop and there are two processes in this stage, so Process 1 is isobaric and:[tex]W_{1}=m*P*(v_{2}-v_{1}) =0.6*1000*(0.4*0.30661-0.30661)=-110.38(KJ)[/tex] and the second process is isochoric:[tex]W_{2}=zero[/tex],now[tex]W_{b}=W_{1}+ W_{2} =110.38+0=110.38(KJ)[/tex]. Finally to get the temperarure at the final state in part (b) we get:[tex]v_{2} =0.4v_{1} =0.4*0.30661=0.122644(m^{3}/Kg), P_{2}=500(KPa)[/tex] from table 2 (see attached) we compare[tex]v_{f}[/tex] and[tex]v_{g}[/tex] at the saturated water table and find the following:[tex]v_{f}=0.001093(m^{3}/Kg)<v_{2}<v_{g} =0.37483(m^{3}/Kg)[/tex], so we know that the final state phase is a satured mixture and we get the temperature at the final state as:[tex]T_{2} =T_{sat} =151.83^{0}C[/tex].

Similar Solved Questions

1 answer

I am standing at point A on one side of a river and wish to measure the distance across a river to a house H on the other side. I walk 50ft along the river bank to point B and measure the angle ABH to be 18°. Find the distance across the river

I am standing at point A on one side of a river and wish to measure the distance across a river to a house H on the other side. I walk 50ft along the river bank to point B and measure the angle ABH to be 18°. Find the distance across the river...
1 answer

N which situation is the distance traveled proportional to time? A) a car moving in stop-and-go traffic B) a person biking on a trail at 12 miles per hour for 20 minutes C) a baseball hit to center field D) a race car slowing down after crossing the finish line

n which situation is the distance traveled proportional to time? A) a car moving in stop-and-go traffic B) a person biking on a trail at 12 miles per hour for 20 minutes C) a baseball hit to center field D) a race car slowing down after crossing the finish line...
2 answers

Arrange the events of succession after a volcano erupted in their proper order. a. pioneer species, plant growth, soil formation b. pioneer species, soil formation, plant growth c. soil formation, pioneer species, plant growth d. soil formation, plant growth, pioneer species Please select the best answer from the choices provided A B C D

Arrange the events of succession after a volcano erupted in their proper order. a. pioneer species, plant growth, soil formation b. pioneer species, soil formation, plant growth c. soil formation, pioneer species, plant growth d. soil formation, plant growth, pioneer species Please select the...
1 answer

One third of an interger​

one third of an interger​...
1 answer

Would you flip the inequality sign, yes or no? Explain why. 2x > –42

Would you flip the inequality sign, yes or no? Explain why. 2x > –42...
1 answer

un scramble with the Spanish words

un scramble with the Spanish words...
1 answer

Which of the following statements about political leaders in foraging bands is true? Group of answer choices They maintain power by nurturing strong ties with the commoner class. They have inherited special access to strategic resources. They maintain control by conquering foreign territories. They have no means of forcing people to follow their decisions. They are the most dominant males in the largest, most powerful descent group.

Which of the following statements about political leaders in foraging bands is true? Group of answer choices They maintain power by nurturing strong ties with the commoner class. They have inherited special access to strategic resources. They maintain control by conquering foreign territories. They ...
2 answers

What is the range for the following function?y=1/x+3+2​

What is the range for the following function?y=1/x+3+2​...
1 answer

What are the main sources of outdoor air pollution and how do they cause smog?​

What are the main sources of outdoor air pollution and how do they cause smog?​...
2 answers

(9,7) and (7,2) Find the slope

(9,7) and (7,2) Find the slope...
1 answer

What pivotal event led the untied states to enter the world war 2

What pivotal event led the untied states to enter the world war 2...
2 answers

Which sentence from the excerpt is foreshadowing and why? The scarlet ibis

Which sentence from the excerpt is foreshadowing and why? The scarlet ibis...
1 answer

Find the slope of the line that passes through (-24, 90) and (-23, 52).

Find the slope of the line that passes through (-24, 90) and (-23, 52)....
1 answer

What is the solution to the system of equations graphed below? A. (0, –1) B. (–3, –1) C. (–2, 3) D. (–3, 2)

What is the solution to the system of equations graphed below? A. (0, –1) B. (–3, –1) C. (–2, 3) D. (–3, 2)...
2 answers

Could somebody help me please

could somebody help me please...
1 answer

What are the two main parts of the argumentative essay? (5 points) Select one: a. Conclusion and counterclaim b. Introduction and thesis c. Thesis and claim d. Claim and counterclaim

What are the two main parts of the argumentative essay? (5 points) Select one: a. Conclusion and counterclaim b. Introduction and thesis c. Thesis and claim d. Claim and counterclaim...
2 answers

Look at the table. Area of Achievement Achievement philosophy combined Islamic faith with Greek logic medicine published a medical encyclopedia mathematics ? Which achievement completes the table? A. invented the telescope B. spread the concept of zero C. invented geometry D. used Roman numerals

Look at the table. Area of Achievement Achievement philosophy combined Islamic faith with Greek logic medicine published a medical encyclopedia mathematics ? Which achievement completes the table? A. invented the telescope B. spread the concept of zero C. invented geometry D. used Roman nume...
2 answers

What is the square root of 64y16? 4y4 4y8 8y4 8y8

What is the square root of 64y16? 4y4 4y8 8y4 8y8...
1 answer

A 1750-kilogram cars travels at a constant speed of 15.0 meters per second around a horizontal, circular track with a radius of 45.0 meters. The magnitude of the centripetal force acting on the car is

A 1750-kilogram cars travels at a constant speed of 15.0 meters per second around a horizontal, circular track with a radius of 45.0 meters. The magnitude of the centripetal force acting on the car is...

-- 0.011304--