Thermodynamics - 3-5 Pure substances property tables - Changing states example 2

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[@구재영엘텍공과대학휴]

11:56 I think the answer is wrong. (b) T=370.70 degrees C P=21225 kPa (c) because of ug=2192.1 KJ/kg, delta U = 1878 KJ Is it right?

[@dimpho_nc]

Same

[@premgandhi3558]

I agree

[@ertus306]

for 11:23 i found T= 370.69 sir did I make an algebra mistake?

[@DrFuture1234]

I spent a solid hour trynna figure out where I went wrong turns out he's the one that did. Happens to the best of us

[@ertus306]

@@DrFuture1234 Yes definitely. I just wanted to know if I was the one who did an error :)

[@abdelz1617]

Great video, thank you!

[@sunmichoi6888]

Thank you so much!

[@robloxkhan5761]

since we moved from saturated liquid state to saturated vapor, shouldnt the T1,P1,T2,P2 be same ? because we are literally going along the liquid vapor mixture line until we reach x=1 (quality)

[@alexandersavadelis8121]

Normally you would be correct, since the temperature is constant along the saturated liquid-vapor mixture line. The problem states that heat is applied to the water until the tank contains saturated vapor only, so we are not following the constant temperature line (T != constant).

[@robloxkhan5761]

@@alexandersavadelis8121 yeah got it. Thanks

[@ibraheemmuslih4389]

the system has a volume in which saturated water occupies only 25%, the remaining is air. That is the entire volume is not only saturated water and part of the supplied heat goes to heat up the air resulting in moving the system to higher levels of temperature and pressure. This shift continues until all water has been evaporated

[@yigitcan824]

@@alexandersavadelis8121 I'm thinking the same thing, why it's not like that after completing the constant temperature line we have also saturated vapor only

[@turk2589]

For this problem, I couldn't get one thing. There is still some air inside the tank. Did you neglect its pressure in the second state? Including the air pressure in the second state and making some assumptions, I calculated the total pressure as approximately 22780 kPa. Is that correct?

[@burhanurrehman2918]

Sir I have a confusion on state 2, the specific volume you calculated comes out to be 0.004626 m^3/kg but on the property table A-4, the specific volume at 200 degrees Celsius is 0.12721 m^3/kg, what value is written on property table and why does it not match our calculated v at 200 degrees C?

[@burhanurrehman2918]

Oh I understood in later part of the video that the temperature was no more 200 degrees C :)

[@ohbandito7155]

Love your content and appreciate it immensely. I do have a question about the table you used to interpolate the three values at the end. I try to work out the problems on my own and then watch your solutions. I used table A-5 instead of table A-4 and while our values for temperature were not exactly the same they are very similar. However my u was different and my final pressure too. What should have tipped me off that I needed to use A-4 and not A-5?

[@michaelmichiel1555]

For state 1, why are we not finding the value of specific volume using a quality of 75% (25/75 ratio). Using that value to find the volume of the tank

[@multi_dramanim]

because the question states that in state 1, its liquid water only and in state two, there are water vapor only, quality is used when there is a mixture of water vapor and liquid water. Don't confuse water vapors with air.

[@anonymousanonymous7878]

Hey, sir. Where can I download the property table that you were using?

[@engineeringdeciphered]

www.dropbox.com/s/tuqy5e8657ysoda/Property%20Tables%20-%20Appendices%201%20and%202.pdf?dl=0

[@thecrazyman8211]

A rigid container with a volume of 0.4 m3 is filled with steam that is at 0.600 MPa and 250 °C. You are required to turn this superheated steam in to a saturated vapor. Calculate the following: a. The mass of water [kg] is inside your container? b. The temperature [°C] when it reaches saturated vapor? c. Energy [kJ] needs to be removed? Can u plz explain this?..

[@ziauddin476]

Send me this book pdf please sir

[@engineeringdeciphered]

Here are the property tables I use: www.dropbox.com/s/tuqy5e8657ysoda/Property%20Tables%20-%20Appendices%201%20and%202.pdf?dl=0 The textbook is by Cengel and Boles