Sökning: "refrigerants"

Visar resultat 21 - 25 av 33 avhandlingar innehållade ordet refrigerants.

1. 21. Flow Boiling Heat Transfer and Pressure Drop. Experiments and Model Development for Complex Geometries

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

   Sammanfattning : 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. LÄS MER

3. 22. Free cooling in commercial buildings. Application with evaporative cooling tower and chilled beams

   Författare :Bengt Bergsten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cooling tower; commercial buildings; simulation; low energy cooling; evaporative cooling; hydronic cooling system; internal heat gain; free cooling; chilled beams; methodology;

   Sammanfattning : The use of electricity in commercial buildings has increased over the last decades. One major cause is the rapid escalation of air conditioning equipment together with a growth of internal heat gains originating mainly from an increased amount of office equipment, which also use electric energy, and high levels of solar irradiation. LÄS MER

4. 23. Investigation of Vapor Ejectors in Heat Driven Ejector Refrigeration Systems

   Författare :Jianyong Chen; Björn Palm; Hans Havtun; Ian W. Eames; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vEjector Refrigeration System; Ejector; Efficiency; Performance; Exergy Analysis; Experiment.; Energy Technology; Energiteknik;

   Sammanfattning : Refrigeration systems, air-conditioning units and heat pumps have been recognized as indispensable machines in human life, and are used for e.g. food storage, provision of thermal comfort. These machines are dominated by the vapor compression refrigeration system and consume a large percentage of world-wide electricity output. LÄS MER

5. 24. Experimental Investigation of Refrigerant Charge Minimisation of a Small Capacity Heat Pump

   Författare :W. Primal D. Fernando; Björn Palm; Alberto Gavallini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat pump; propane; low-charge; Wilson plot method; minichannels; aluminium heat exhangers; single.phase flow; Mechanical and thermal engineering; Mekanisk och termisk energiteknik;

   Sammanfattning : Enormous quantities of heat are available in air, soil, water, exhaust air from buildings, and in waste water of any kind. However these heat sources are use-less for heating purposes since their temperatures are lower than the tempera-ture required for heating. LÄS MER

7. 25. Waste-Heat Recovery from Combustion Engines based on the Rankine Cycle

   Författare :Gunnar Latz; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rankine cycle; waste heat recovery; energy losses; energy efficiency; vehicle propulsion;

   Sammanfattning : The majority of the energy in the fuel burned by the combustion engines used in modern vehicles is lost in the form of waste heat and does not contribute to the propulsion of the vehicle. Three different technologies have been proposed for recovering some of this lost heat and thereby increasing the overall efficiency of combustion engines: the turbocompound, thermoelectric converters, and heat engines based on the Rankine cycle. LÄS MER