Abstract: The performances of thermodynamics cycles are dependent on the properties of refrigerants. The performances of Vuilleumier (VM) cycle heat pump adopting mixture refrigerants are analyzed by MATLAB software using REFPROP programming. At given operating parameters and configuration, performances of the VM cycle adopting pure refrigerant, H2, He or N2 are compared. Thermodynamic properti...

A computer model representing a two-evaporator, two-intercooler refrigerator-freezer opera ting at steady-state with nonazeotropic refrigerant mixtures (CYCLEZ) has been developed at Oak Ridge National Laboratory (ORNL). This model is being used to assess the effects of system desig n and operating parameters on the cycle performance of a refrigerator-freezer designed around the L orenzMeutzner...

Cryosurgery is a technique for destroying undesirable tissue, such as cancers, by exposing it to a very low temperature. This paper presents a thermodynamic modeling tool that has been developed for a two stage, mixed gas Joule-Thomson (MGJT) cryoprobe used for cryosurgery. A conventional vapor compression (VC) cycle using a pure refrigerant precools the MGJT cycle providing refrigeration at th...

Mixed refrigerants are obtained from mixing pure in specific proportions and it is known as mixed refrigerants. Mixture divided into two groups according to their thermodynamic behavior: zeotropic mixtures azeotropic mixtures. In this study, the performance of R410A refrigerant mixture (R125 R32) vapor compression refrigeration cycle was investigated. The coefficients (COP) cooling system under...

Variable-speed centrifugal compressors are used in a wide variety of industries and applications, including natural gas pipelines and processing plants, oil refineries and chemical plants, air-separation units, refrigeration and air conditioning equipment refrigerant cycles, gas turbines and auxiliary power generators, and many more. Some natural gas plants, for example, employ a propane-precoo...

Optimization of the refrigerant circuitry can improve a heat exchanger’s performance. Design engineers currently choose the refrigerant circuitry according to their experience and heat exchanger simulations. However, the design of an optimized refrigerant circuitry is difficult. The number of refrigerant circuitry candidates is enormous. Therefore, exhaustive search algorithms cannot be used an...

Xin Liu Carlyle Compressor Division Carrier Corporation 6500 Chrysler Drive syracuse, NY 13221 Many researchers have believed and claimed that the application of non-azeotropic refrigerants would increase air conditioning or heat pump cycle efficiency. Some of them have carried out experiments in order to confirm their belief, and especially to provide an approach to air conditioner or heat pum...

The errors associated with therModynamic performance calculations are discussed with particular reference to systems with a high oil charge. It is shown that calculations made using published refrigerant data can be very misleading as no account is taken of the oil solubility effects. Pressure-enthalpy charts are presented for refrigerant R12 oil mixtures, for a range of oil concentrations. The...