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How to correct the effect of gas compression coefficient on flow measurement

How to correct the effect of gas compression coefficient on flow measurement

The problem is raised. There is a gaseous ammonia from the ammonia evaporator, which is measured by the vortex flowmeter.
Product flow q,. After that, it is converted to the volume flow q in the standard state. And then calculate its mass flow, using
Is the ideal gas equation shown in equation (8.12) feasible? the answer is negative.
q,. One; l ≥ qVf c8. ,2,
In the formula, Tf, pf, q, f- working gas absolute temperature, absolute pressure, volume flow;
Tn, p. , q,. ——The absolute temperature, absolute pressure and volume flow of the gas under standard conditions.
Because the critical temperature is higher and the critical pressure is lower, the relationship between temperature, pressure and volume deviates from the ideal.
The gas equation is more serious. If this deviation is not compensated, it will cause a large error.
The gas compression coefficient Z is the correction of this deviation phenomenon. For example, in a vortex flowmeter, the available formula (8.13)
Make corrections:
Wherein the gas compression coefficient in the Zf-working state;
Zn - gas compression coefficient in standard state;
The meaning of the remaining symbols is the same as in (8.12).
(2) The calculation of the compression coefficient The compression coefficient of the gas is not only related to the critical temperature and critical pressure of the gas, but
And related to the working conditions of the gas, ie
Z= f(Tc, township, Tf, pf)
The compression coefficient of Z-gas under T and eve conditions;
Tc——the critical temperature of the gas, K;
township. ——The absolute pressure of gas, MPa;
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Tf-working state gas absolute temperature, K;
Pf - working state gas absolute pressure, MPa.

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