00:01
Problem 6 .28.
00:03
In this problem, steam is entering a turbine.
00:08
So for the turbine, if we draw a t .s.
00:13
Diagram, so this is basically, let's say this is temperature axis and this is entropy axis and the dome is like this and the dome is like this and the steam is passing through this let's say so this is this is the state one and it is expanding in turbine and this is and from some intermediate stage let's say stage two the steam is extracted and finally it is exiting at state three corresponding to this three state quality of the steam is quality of this team corresponding to this state is 0 .9 that is 90 % all right so first of all we would need the properties corresponding to these points initially it is entering at so if we go for the state 1 so if we write the properties at state 1 the fluid is entering or the steam is entering with volume flow rate that is let's say volume flow rate i'm writing it as discharge that is q and that discharge is 5 meter cube per second.
01:47
From the superheated steam table, we can calculate the properties of the steam and we would need to find the density at this stage.
01:56
So from there, we can find the density and density is, that is one by specific volume and that comes out to be 10 .063 kg per meter cube.
02:12
So we can find the mass flow rate of the steam entering inside the turbine.
02:19
So mass flow rate of the steam entering the turbine will be q into row 1.
02:28
That is equals to 10 .063 multiplied by 5 kg per second which is 10 m .1 is equal to 10 .063 multiplied by 5 that is 50 .315 kg per second so this is the mass flow rate that is entering the steam turbine.
03:00
Now at state 2, some steam is extracted.
03:05
Let's say, and in the problem it is given that 15 % of the mass is extracted at state 2.
03:13
So mass m .2 will be 15 % of m1, that is equals to 0 .15 multiplied by m1 is 50.
03:32
315 kg per second so m2 dot will be 7 .547 kg per second so this is the mass flow rate that is extracting extracted and we have to find the volume flow rate in the problem they have asked about volume flow rate since we have already calculated the mass flow rate so we can relate this mass flow rate with volume flow rate as m2 dot is equals to row 2 into q2 where q2 is the volume flow rate that is discharge volume flow rate at so we can put these values and we have but to calculate this value we need to find row 2 and row 2 is the property of steam at state 2 now state 2 has the property since the steam is extracted at 6 600 kilo pascal and 200 degrees celsius so corresponding to 600 kilo pascal and 200 degrees celsius using the super heated steam table we can get the value of density at this point and row 2 comes out to be 2 .84 kg per second so this value is calculated from steam table that is basically being more specific superheated steam table so from here we can put these values m2 that is 7 .547 that is equals to 2 .84 multiplied by q2 so from here the q2 comes out to be 2 .657 meter cube per second so this is the volume flow rate exiting at or extracted at a state 2 this is the the answer.
05:42
Now the remaining volume is flowing through the turbine rest of the part of the turbine and it will exit at state 3...