Functional Dependence of Thermodynamic and Thermokinetic Parameters of Refrigerants Used in Mine Air Refrigerators. Part 1 – Refrigerant R407C

Abstract

The authors of this article dealt with the issue of modeling the thermodynamic and thermokinetic properties (parameters) of refrigerants. The knowledge of these parameters is essential to design refrigeration equipment, to perform their energy efficiency analysis, or to compare the efficiency of air refrigerators using different refrigerants. One of the refrigerants used in mine air compression refrigerators is R407C. For this refrigerant, 23 dependencies were developed, determining its thermodynamic and thermokinetic parameters in the states of saturated liquid, dry saturated vapour, superheated vapor, subcooled liquid, and in the two-phase region. The created formulas have been presented in Tables 2, 5, 8, 10 and 12, respectively. It should be noted that the scope of application of these formulas is wider than the range of changes of that refrigerant during the normal operation of mine refrigeration equipment. The article ends with the statistical verification of the developed dependencies. For this purpose, for each model correlation coefficients and coefficients of determination were calculated, as well as absolute and relative deviations between the given values from the program REFPROP 7 (Lemmon et al., 2002) and the calculated ones. The results of these calculations have been contained in Tables 14 and 15. Keywords: refrigerants, R407C, thermodynamic and thermokinetic parametersAutorzy niniejszego artykułu zajęli się zagadnieniem modelowania właściwości (parametrów) termodynamicznych i termokinetycznych czynników chłodniczych. Znajomość tych parametrów jest niezbędna do projektowania urządzeń chłodniczych, ich analizy energetycznej, a także do porównaniu efektywności pracy chłodziarek powietrza wykorzystujących różne czynniki chłodnicze. Jednym ze stosowanych w gór-niczych sprężarkowych chłodziarkach powietrza czynnikiem chłodniczym jest R407C. Dla wymienionego czynnika chłodniczego opracowano 23 zależności określające jego parametry termodynamiczne i termokinetyczne w stanie cieczy nasyconej, w stanie pary nasyconej suchej, w stanie pary przegrzanej, w stanie cieczy przechłodzonej oraz w stanie pary mokrej. Utworzone wzory podano odpowiednio w tabelach: 2, 5, 8, 10 i 12. Należy zaznaczyć, że zakresy obowiązywania tych wzorów są szersze od zakresów zmian

Functional Equations for Calculating the Properties of Low-GWP R1234ze(E) Refrigerant

“…The sought-after thermodynamic and thermokinetic properties were described using 3, 4, 5, 6, 8, or 9 degree polynomials, whose coefficients were determined using STATISTICA 12 [33]. As in [34][35][36][37], the Levenberg-Marquardt algorithm-one of the methods used for non-linear least squares estimation-was used for this purpose. The Levenberg-Marquardt algorithm is used directly or indirectly in many technology fields, such as energy flow research [38], heat transfer [39,40], PV module parameters [41,42], and water flow [43].…”

Archives of Mining Sciences

“…Artificial refrigera-tion is a method in which work is done to remove heat from one location to another by using manual methods [15]. According to the type of secondary refrigerant, the artificial refrigeration system can be divided into a central air conditioning cooling system, ice cooling system, and water cooling system [16,17]. The secondary refrigerant is an intermediate cooling medium that transfers heat from a space to the refrigerant [18].…”