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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

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

   Författare :Roger Tuomas; Luleå tekniska universitet; []
   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

3. 2. Corresponding States Correlations for the Prediction of Thermodynamic Properties of Refrigerants

   Författare :Maria Sörner; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; refrigerant mixtures; corresponding states; parameter estimation; equation of state; refrigerants; thermodynamic properties;

   Sammanfattning : When process equipment such as separation units, heat pumps, and refrigeration systems are simulated or designed, physico-chemical properties of the fluids involved must be known. The outcome of the simulation or design depends on the accuracy of the correlations used in the prediction of physico-chemical data, so it is of the utmost importance that the correlations used correctly describe the properties of the fluids. LÄS MER

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

   Författare :Vijaya Sekhar Gullapalli; Institutionen för energivetenskaper; []
   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

5. 4. 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

   Författare :Pavel Makhnatch; Rahmatollah Khodabandeh; Angelo Maiorino; KTH; []
   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

7. 5. Determination and evaluation of pressure-volume-temperature relationships of some halogenated hydrocarbons and their binary mixtures : an experimental and theoretical study

   Författare :Krister H. U. Ström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; liquid molar volume; vapour pressure; vapour-liquid-equilibria; equations of state; corresponding state principle; thermodynamic properties; refrigerants; refrigerant mixtures;

   Sammanfattning : .... LÄS MER