A comparative analysis of a new semi-empirical model and the AHRI polynomial model for positive displacement compressors

• Published in: International journal of refrigeration 2024-03, Vol.159, p.254-263
• Main Authors: Hjortland, Andrew L., Crawford, Roy R.
• Format: Article
• Language: English
• Subjects: Compresseur volumétrique; Compressor modeling; Consommation d'électricité; Discharge temperature; Débit; Flow rate; Modélisation du compresseur; Positive displacement; Power consumption; Température de refoulement
• ISSN: 0140-7007; 1879-2081
• DOI: 10.1016/j.ijrefrig.2023.12.009

•The prediction accuracies of a semi-empirical modeling approach and the AHRI polynomial modeling approach are compared.•A data set containing twenty-six combinations of compressors and refrigerant pairs wherein each compressor was tested over a wide range of operating conditions is used to evaluate the models.•The model parameters were fit using all the data from each data set, as well as smaller subsets of data using a resampling approach.•The semi-empirical model showed more consistent prediction errors when fewer data points were used to fit the model.•The AHRI polynomial model is unsuitable for predicting the discharge temperature of a compressor when variations in suction superheat are present. A semi-empirical model has been proposed to predict the refrigerant mass flow rate, input power, and discharge temperature of positive displacement compressors. The prediction accuracy of the proposed model is compared with the accuracy of the AHRI polynomial model. To examine the generalizability of the models, a resampling methodology is used to compare prediction accuracy that results when smaller data sets are used to fit the models. These results show that the semi-empirical model has similar mass flow rate and input power prediction errors to the AHRI polynomial model and results in more consistent performance when smaller data sets are used to fit the model. The results also show that the AHRI polynomial is not a good choice for the prediction of discharge temperature and that the proposed model is much more suitable for this purpose.