Experimental Investigation of the Enthalpy of Isobutane−Compressor Oil Solutions

Abstract

This paper reports new experimental data for the specific enthalpy of the solution of isobutane (refrigerant R600a, CH(CH 3 ) 2 -CH 3 , CAS Registry No. 75-28-5) with mineral naphthenic compressor oil WF 15A. The experimental data were obtained in the temperature range from (273 to 355) K by a mixing method realized in an ice calorimeter. The behavior of the temperature and weight fraction dependencies of the enthalpy for the refrigerant-oil solution (ROS) of R600a and mineral compressor oil WF 15A have been examined.

Локальний Коефіцієнт Тепловіддачі При Кипінні Розчину Ізобутан/ Мінеральне Мастило В Трубі

“…The next stage of experimental data processing is the thermodynamic modeling of boiling ROS in the pipe using experimental data concerning properties of the real working fluid [10].…”

“…The present study of local values of the heat transfer coefficient during boiling of RWF in the pipe has a number of features compared with previously published data in the literature [e.g., 1,3,4,8,9]. The experimental data on the thermal properties of the solutions R600a/ISO VG 15 were used to processing the data instead calculated [10].…”

“…The ROS mass velocity on the test section is calculated by the equation To determine the local vapor qualities RWF in the evaporator x ROS local it is necessary to have information about the enthalpy before throttling deviceh ROS in. The enthalpy value is determined using experimental data on thermophysical properties of solution R600a/ISO VG 15 and calculated by the equation [10]…”

“…where h0, βcoefficients, defined from the experimental data [10]; hcenthalpy value at critical point, kJ/kg; τ=ln(Tc/T)reduced temperature; Fh'(τ)universal crossover function for the non-associated substances [10] Local enthalpies of RWF on the evaporator sections are calculated by the equation…”

“…The enthalpy of oil ISO VG 15 hlocal О was taken from the experimental data [10]. Information for the enthalpy of the R600a in liquid hlocal R,l and vapor hlocal R,g phases was taken from the data bases [11].…”