Recent content by rancam

Sorry I forgot to mention that the pressure is 855 psig and there is about a 10 % exit of the gas with a simlultaneous 10 % entrance of CO2 so that at the end of the second the pressure and weight of the gas is the same.Can I use the heat transfer formula with the CO2 coefficient (.0081 btu /...

Homework Statement Can you please help me with this thermodynamic question?I am not a student. An aluminum cylinder with an interior area of 4.1875 sq ft (or 603 sq in) contains 7.445 lbs of CO2 gas under pressure.The volume of the cylinder is .582 cu ft.The temperature of this gas is 110 deg...

Thanks again for your help.

As a beginner I think I've reached the limit of my understanding thermodynamics and its accompanying math.I think its now time to study the required math and perhaps we can resume this conversation.Thanks for your time and patience.

OK.I'm sorry,I did not bring my CO2 properties manual to the library with me,so I can't look up the Cp at state B and C.I've read it would be an average of the two.I think your method works like this;First the change in enthalpy; -5026.4 - -3334 = 1692.4.Change in enthalpy is Cp x T so H / Cp =...

Yes.Please do.It would be very helpful.

I was thinking per unit mass.No more questions but a clarification regarding isentropic compression.Using the compression of 47.3 bar isentropically and adiabatically up to 65bar as an example.Using my manual of CO2 properties the temperature,entropy and enthalpy at 47.3 bar (vapor pressure)...

Do you mean higher than the average of the sum of the entropies (in my case it would be higher than -42.6+-45.2 =- 87.8 / 2 = -43.9),and is it proportional,so that if the proportions were 1/4 gas -42.6 and 3/4 at -45.2 the final entropy would be more than -44.55.If so could not the final entropy...

When you say higher than the original entropy of the system do you mean higher than both the higher or lower pressure gas,or just higher than the higher pressure gas.(I am assuming that the higher pressure gas has a lower entropy than the lower pressure gas.Using my example the 47.3 bar gas is...

As I am at the public library that might take some time.I was just reading a statement by a member that when gases mix the entropy always increase.My example is contrived.Lets say the gas does no work on the piston which is activated by an outside force (electrical).I just want to know whether...

I don't have a picture available at this time.Assuming this scenario is as I have described,do you whether whether the final entropy would be greater than the initial value of -42.6,or somewhere in between -42.6 and 45.2?

May I ask one final question?What if CO2 gas at pressures of 47.3 bar, S=-42.6 and 56.6 bar,S= -45.2 were mixed?,as follows.There are two cylinders of the same volume,one open,full of CO2 at 47.3 bar (cylinder A),the other closed (cylinderB).A pipe connects the two cylinders.As a piston pushes...

Thanks for your help

Sorry,in the last sentence I meant to say ,applying the ideal gas equation,the pressure should be higher,and hence the entropy should be lower,than the values at the vapor pressure and temperature (meaning neither subcooled nor superheated).

An undergraduate gave me a similar formula for isentropic compression (S1=S2).S (vapor) for 47.3 bar is -42.6,the S for 56.6 bar is- 45.2 (vapor) and- 68.51 (liquid). So, -42.6 = (1-q) -68.51+q-45.2,q = 1.111 superheated vapor.Now,is it permissible to do what you did with adiabatic...