Sökning: "refrigerant properties"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden refrigerant properties.

  1. 1. Properties of oil and refrigerant mixtures lubrication of ball bearings in refrigeration compressors

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Roger Tuomas; Luleå tekniska universitet.; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machine Elements; Maskinelement;

    Sammanfattning : A refrigeration compressor contains highly loaded mechanical contacts that have to be lubricated. The lubricant used in refrigeration compressors consists of an oil and refrigerant mixture, and the refrigerant concentration can be up to 40 wt%. LÄS MER

  2. 2. Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers

    Detta är en avhandling från Department of Energy Sciences, Lund University

    Författare :Vijaya Sekhar Gullapalli; Lund University.; Lunds universitet.; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brazed plate heat exchangers; CFD; heat transfer; pressure drop; heat exchanger selection software; transcritical-CO2 calculations; heat exchanger rating; evaporation; condensation; refrigerant properties; discretized calculations;

    Sammanfattning : This thesis work presents various performance estimation methods of compact brazed plate heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and transcritical applications. Such methods play a vital role in development of heat exchanger selection software and during geometry parameter estimation in the new product development process. LÄS MER

  3. 3. New refrigerants for vapour compression refrigeration and heat pump systems : evaluation in a context of the requirements set by the F-gas Regulation and the Paris Agreement goals

    Detta är en avhandling från Universitetsservice US-AB

    Författare :Pavel Makhnatch; KTH.; [2019]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; refrigerant; retrofit; drop-in; HFC; HFO; F-gas Regulation; Kigali Amendment; Montreal protocol; Life cycle climate performance; LCCP; climate change; Energiteknik; Energy Technology;

    Sammanfattning : Given the global commitment to reduce the impact of fluorinated gases on climate and the regulations controlling their use in the European Union (EU), this thesis investigates new refrigerants that have been recently proposed to meet the demands of the refrigeration industry in the EU, which must satisfy the legislative requirements of the F-gas Regulation and facilitate meeting the goals of the Paris Agreement.The legislative requirements of the EU have intensified refrigerant development with reduced GWP. LÄS MER

  4. 4. Bearing lubrication of refrigeration screw compressors

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Roger Tuomas; [2001]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Sammanfattning : The bearings in a modern refrigeration screw compressor are lubricated with a mixture of oil and refrigerant. However, little or no published bearing life data is available for the new generation non-chlorinated refrigerants. LÄS MER

  5. 5. Elastohydrodynamic lubrication and lubricant rheology in refrigeration compressors

    Detta är en avhandling från Luleå : Luleå tekniska universitet

    Författare :Ulf Jonsson; [1998]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Sammanfattning : The introductory chapter gives a general description of the lubrication of rolling element bearings in refrigeration compressors and rheological properties of oil-refrigerant mixtures. The influence of refrigerants on the viscosity, pressure-viscosity coefficient and film forming ability in a EHD-contact is described. LÄS MER