Acquiring method and system for compression factor

Abstract

The invention discloses an acquiring method and system for a compression factor. The method comprises the following steps: acquiring experimental compression factors Zi of a to-be-tested working medium with a preset fixed volume at (Ti, pi) state points when the to-be-tested working medium is of different preset fixed mass, i.e., acquiring discrete compression factors by using an experimental method; then constructing a training sample set according to the discrete compression factors; and constructing a compression factor prediction model by using an LS-SVM method according to the training sample set, wherein the compression factor prediction model is relational expression for a to-be-solved state point (T,p) and a compression factor Z corresponding to solving. According to the invention, the discrete compression factors are obtained by using an experiment method; then model prediction is carried out on the discrete compression factors so as to obtain the compression factor prediction model; and a continuous compression factor can be obtained by using the compression factor prediction model. Thus, the acquiring method and system can finish acquisition of the compression factor of any working medium at different temperature and different pressure.

Description

technical field [0001] The present invention relates to the technical field of compression factors, and more specifically, to a method and system for obtaining compression factors. Background technique [0002] Compressibility factor (compressibility factor, abbreviated as Z) is one of the important thermophysical parameters of working fluid, which is often used to calculate other physical parameters. Since the compressibility factor Z changes with the change of temperature T and pressure p, therefore, in the process of During engineering calculation, it is necessary to obtain the compression factor Z under different (T,p) states. [0003] Using the corresponding state law to solve the compression factor is a commonly used method at present. The method is specifically: according to the temperature T of the working fluid to be measured, the pressure p and the corresponding critical temperature T c and critical pressure p c , get the contrast temperature T r and contrast p...

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Problems solved by technology

At the same time, for the critical temperature p of the working fluid to be tested that needs to be known in advance c and critical temperature T c , in actual operation, for new working fluid or mixed working fluid, the critical temperature p c and critical temperature T c is often missing

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