Search for dissertations about: "refrigerant"

Showing result 21 - 25 of 30 swedish dissertations containing the word refrigerant.

  2. 21. Evaporative and Desiccant Cooling Techniques Feasibility When Applied to Air Conditioning

    Author : Torbjörn Lindholm; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; desiccant wheel; desiccant cooling; evaporative cooling; dehumidification; air-conditioning; HVAC; comfort;

    Abstract : This thesis describes evaporative and desiccant cooling processes for air-conditioning purposes, i.e. for the removal of surplus heat from premises by the supply of cooled ventilation air. These cooling processes can replace the conventional method of cooling ventilation air involving the use of refrigerating machinery. READ MORE

  4. 22. Flow Boiling Heat Transfer and Pressure Drop. Experiments and Model Development for Complex Geometries

    Author : Sven Wellsandt; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; pressure drop; zeotropic mixtures; heat transfer; herringbone microfin; dimple plate; modelling; evaporation; flow boiling; experiments;

    Abstract : Two very different evaporator geometries, a dimple plate and a herringbone microfin tube, have been studied. Heat transfer and pressure drop for both pure refrigerants and refrigerant mixtures have been determined experimentally. READ MORE

  5. 23. Thermal and hydraulic performance of compact brazed plate heat exchangers operating as evaporators in domestic heat pumps

    Author : Joachim Claesson; Björn Palm; Satish G. Kandlikar; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; plate heat exchanger; evaporator; heat pump; flow boiling; pressure drop; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Abstract : This thesis investigates the performance of compact brazed plate heat exchangers (CBE) operating as evaporator in heat pump applications. The thesis, and the performances investigated, has been divided into three main sections; One zone evaporator performance; Two zone evaporator performance; and finally Local performance. READ MORE

  6. 24. HFC Mixtures as Replacement for HCFC-22 in Large-Scale Heat Pumps and Chillers

    Author : Cecilia Gabrielii; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; R404A; R143a; R125; performance; R134a; R32; replacement; zeotropic HFC mixtures; simulations; design; measurements; chiller; R407C; condenser evaporator; screening; optimization; heat pump; R22;

    Abstract : Replacement of the conventional refrigerant HCFC-22 (R22) is one of the urgent issues to be solved within the scheduled time-frame of the international regulation of the HCFCs. Since there exists no pure fluid that can replace R22 in the same general way as HFC-134a (R134a) is a replacement for CFC-12, HFC mixtures are suggested as possible substitutes. READ MORE

  7. 25. State-of-the-art Integrated Refrigeration Systems in Supermarkets : An Energy Efficiency Evaluation Based on Field Measurements Analysis and Computer Simulations

    Author : Mazyar Karampour; Samer Sawalha; Björn Palm; Silvia Minetto; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Carbon dioxide CO2 ; Supermarket; Supermarket refrigeration; Trans-critical cycle; Field meas-urements; Computer simulation; System integration; State-of-the-art; Heat recovery; Air condi-tioning; Reference HFC system; Geothermal energy storage; Energiteknik; Energy Technology;

    Abstract : Supermarkets have become a vital feature of modern society. However, they have significant impact on the environment due to the large amount of refrigerants needed in the refrigeration system, and due to the large energy use in the supermarket, they are the commercial buildings with highest energy intensity. READ MORE