Gas molar heat capacity
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The molar heat capacity of gases is approximated by polynomials under different temperature conditions. The coefficients and formulas of the two books I consulted, "Chemical Thermodynamics" (Beijing Normal University, Li Dazhen) and "Chemical Process Calculation" (East China Chemical Industry, Wu Zhiquan), are different. What data do you use as the chemical engineering design standard?
If you use both methods to calculate, how much difference can there be in the result?
Now I am posting the two calculation results, please help with analysis.: 1) Chemical process calculation: CP=A+B * T+C * T^2+D * T^3=27.55+0.0256278 * 373+9.90042 * 10^-6 * 373^2-6.68639 * 10^-9 * 373^3=38.13961 2) Basics of chemical thermodynamics CP=A+B * T+C * T^2=25.895+0.032999 * 373-3.046 * 10^-6 * 373 * 373=37.77984 From two levels to numbers, the two are almost the same, but one thing is that the chemical production volume is generally larger, and the absolute value of the calculation difference between the two is not small.
These formulas are originally empirical formulas and are not very accurate. If you are unsure, just take an average value! If the error can be smaller, if it still doesn't work, you can use the iterative method.
It seems that none of the specific heat capacity formulas in the physical property data volume of the "Nitrogen Fertilizer Process Design Manual" were calculated correctly. I wonder if my company is wrong? It’s the specific heat capacity formula of those gases