Pavan Kumar
Chemical
- Aug 27, 2019
- 334
Hi All,
I am sizing an expansion tank for Hot Glycol re-circulation loop. The temperature of the Glycol ( 40% Ethylene Glycol in water) increases from 55 to 60 Deg C across a gas fired heater. The hot glycol transfers heat across an Pipe-in-Pipe Heat exchanger to heat the process fluid inside the inner pipe. Per the thread below, I see that the volume change can be calculated as DV = Beta * Vavg * DT.
where
Beta = Coefficient of Cubical Expansion = [(Rho1 ^2) -( Rho2 ^2)] / (2*(Rho1* Rho2)*(t2-t1)
t1 = Initial temperature = 55 Deg C
t2 - final temperature = 60 Deg C
Rho1 = 63.924 lb/ft3
Rho2 = 63.741 lb/ft3
Vavg = 2 / (Rho1 + Rho2)
Using this method I get the following results,
Beta = 0.0003175 1 / Deg F
Vavg = 0.0157 ft3 / lb
DV = 4.5 X 10 ^(-5) ft3 / lb
The pipe volume is 110 ft3
and Glycol mass in the pipe= 110*63.924 = 7011.5 lb
So the actual volume change = 4.5 x 10^(-5) * 7011.5 = 0.3139 ft3 = 2.35 US gallons.
My Questions:
1. I have to size the expansion tank for 2.35 US gallons correct?
2. I have to size the expansion for the volume increase correct?. If yes I see the volume increase is very small. I want to make sure what I am doing is correct. Any guidance will be very helpful to me.
Thanks and Regards,
Pavan Kumar
I am sizing an expansion tank for Hot Glycol re-circulation loop. The temperature of the Glycol ( 40% Ethylene Glycol in water) increases from 55 to 60 Deg C across a gas fired heater. The hot glycol transfers heat across an Pipe-in-Pipe Heat exchanger to heat the process fluid inside the inner pipe. Per the thread below, I see that the volume change can be calculated as DV = Beta * Vavg * DT.
where
Beta = Coefficient of Cubical Expansion = [(Rho1 ^2) -( Rho2 ^2)] / (2*(Rho1* Rho2)*(t2-t1)
t1 = Initial temperature = 55 Deg C
t2 - final temperature = 60 Deg C
Rho1 = 63.924 lb/ft3
Rho2 = 63.741 lb/ft3
Vavg = 2 / (Rho1 + Rho2)
Using this method I get the following results,
Beta = 0.0003175 1 / Deg F
Vavg = 0.0157 ft3 / lb
DV = 4.5 X 10 ^(-5) ft3 / lb
The pipe volume is 110 ft3
and Glycol mass in the pipe= 110*63.924 = 7011.5 lb
So the actual volume change = 4.5 x 10^(-5) * 7011.5 = 0.3139 ft3 = 2.35 US gallons.
My Questions:
1. I have to size the expansion tank for 2.35 US gallons correct?
2. I have to size the expansion for the volume increase correct?. If yes I see the volume increase is very small. I want to make sure what I am doing is correct. Any guidance will be very helpful to me.
Thanks and Regards,
Pavan Kumar