The exhaust temperature is 600•C and exhaust pressure is 5 kg f/cm^2.
Anemometer can not be used. What approach or method should I use ?
Can this be found theoretically ?
You can estimate exhaust flow velocity using engine and exhaust pipe data.
[1] You need to know the following as inputs:
(1) brake power at which the engine is running, P (kW), or alternatively
(2) Engine speed N (rpm) and torque T (N-m), then P = 2*pi*(N/60)*T/1000 (kW)
(3) LHV of the diesel fuel, LHV, ~ 46500 (kJ/kg)
(4) Engine efficiency E (%), usually 42-46% for a modern 1200 HP diesel engine.
[2] The you can estimate the fuel consumption F at this operating condition.
(1) F = P / (LHV/3600*E/100) (kg/h)
[3] Calculate the air flow and exhaust gas flow.
(1) The air flow is Fa = F* (AFR). AFR = 18 - 85 for diesel engines. Assume AFR = 23 if this operating point sits in the middle of the engine map, if you don't have any data available.
(2) The total exhaust gas flow Feg = F + Fa. (kg/h)
(3) The molecular weight of exhaust gas MWeg is approximately 28.75 (g/mol).
(4) EG volume flow Veg = (Feg/MWeq)*22.414*(T+273)/273 *1.013/P, (m3/h)
[4] If you know the diameter of the EG pipe and the cross sectional area, the E flow velocity can be calculated from
U = (Veg/3600) /A (m/s)
Hope this helps. Good luck.
Thank you sir!
Please explain this
) F = P / (LHV/3600*E/100) (kg/h)
What does E/100 mean ?
E is efficiency. For an efficiency of 42% you use 42/100 in the equation.
In the equation
F = P / (LHV/3600*E/100),
F = Fuel flow to engine (kg/h)
LHV = Lower heating value of diesel fuel (kJ/kg)
E = Brake efficiency of engine (%)
Please also make sure that the unit of engine power should be converted from hp to kW. 1 hp = 0.7457 (kW).
Xuantian Li!
Can you please share the references for all this or suggest me some book where I can do more study on this. I'll be very grateful !
Please suggest me books or source for the provided equations for the calculation of exhaust gases velocity ..
For the equation in Step [1]: P = 2*pi*(N/60)*T/1000 (kW), you may cite "John B. Heywood, Internal combustion engine fundamentals. McGraw-Hill, New York (1988)" as a general reference. Other equations can all be derived by yourself from first principle.