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...

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...

Abstract: Minimizing the work consumed in refrigeration system is the most effective measure to reduce the cost of products in sub-ambient chemical processes. The introduction of mixed working fluids into refrigeration system in place of pure working fluids is a recent advancement applied in the field. Due to the lack of systematic design method for Mixed Refrigerant Cycle (MRC), conventional a...

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...

Title of Document: Efficiency Enhancement for Natural Gas Liquefaction with CO2 Capture and Sequestration through Cycles Innovation and Process Optimization Abdullah Alabdulkarem, Doctor of Philosophy, 2014 Directed By: Professor, Reinhard Radermacher, Mechanical Engineering Liquefied natural gas (LNG) plants are energy intensive. As a result, the power plants operating these LNG plants emit hi...

In the present work, various objective functions were formulated and optimized using mixed integer nonlinear programming generalized reduced gradient method from solver tool of Microsoft® Excel 2016, respectively. The CH3FO2, C2H4F2O, CH2F2O2, CH2F2O, C3H4F2, C2H2F2O molecules found to meet structural feasibility constraints physical properties refrigerant have not previously been reported in l...

The given paper is aimed at constructing the general circuit of heat processes in a semihermetic reciprocating refrigerant compressor as a basis of application of new ecology-friendly refrigerants as well as optimizing design parameters of compressor. While performing this work the following problems were solved: 1. Experimental research of heat processes in a semihermetic refrigerant reciproca...

This paper presents the heat transfer coefficients and the pressure drop measured during HC-600a (Isobutane) condensation inside a brazed plate heat exchanger: the effects of saturation temperature, refrigerant mass flux and vapour super-heating are investigated. The heat transfer coefficients show weak sensitivity to saturation temperature and great sensitivity to refrigerant mass flux. At low...

The refrigerant release technology relieves even eliminates the over-compression loss of scroll compressor by bypassing the refrigerant in the compression chamber to the suction pipe under small system pressure ratio conditions. Because the room air conditioner works in mild conditions at most of the time, its seasonal energy performance is expected to be effectively improved by the refrigerant...