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Fumes energy

  1. Oct 10, 2011 #1
    Hi!

    I'm working on problem, where I have to estimate energy, lost due to flue gases, i.e. some amount of natural gases burned in some time period, say [t0;t1].
    Burning is used for some material heating. I need to find energy, lost by gases (gases, after combustion), which goes out from flue. Heating is performed linearly, for example from point [0;100] to [2;400] (first coordinate is time in hours and second is temperature), so temperature dependence is like this:
    T(t)=150t+100​
    I was told that I have to calcule specific enthalpy change in order to calculate energy lost by fumes:
    Qf=MΔhf
    where M is mass of fumes and Δhf is specific enthalpy change.
    Also I know that specific enthalpy depends on temperature throuth relation:
    hf(T)=0.28T-4.6​

    So, for specified heating schedule, enthalpy depends on temperature through this:
    hf(t)=0.28(150t+100)-4.6=42t+23.4​

    I'm I write, when I calculate change of specific enthalpy by integrating in time interval function hf(t)?:

    Δhf=∫(42t+23.4)dt​
     
  2. jcsd
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