Sökning: "R404A"

Hittade 5 avhandlingar innehållade ordet R404A.

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

   Författare :Cecilia Gabrielii; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 2. Phase-out of refrigerant R22

   Författare :Anders Johansson; KTH; []
   Nyckelord :Retrofit; Phase-out; CFC; HCFC; HFC; R22; R407C; R417A; R404A; R134a; Ozone depletion; Zeotropic refrigerant mixture; Circulated composition; Measurement; Energy; Energy efficiency; System; Systems analysis; Modelling; Simulation; Prediction;

   Sammanfattning : .... LÄS MER

4. 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

   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

5. 4. Carbon Dioxide in Supermarket Refrigeration

   Författare :Samer Sawalha; Björn Palm; Eckhard Groll; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CO2; carbon dioxide; refrigeration system; supermarket; cascade; indirect; trans-critical; modelling; simulation; experiment; safety analysis; comparison; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : This thesis theoretically and experimentally investigates different aspects of the application of CO2 in supermarket refrigeration. Theoretical analysis has been performed using computer simulation models developed to simulate CO2 indirect, NH3/CO2 cascade, CO2 trans-critical and direct expansion (DX) R404A systems. LÄS MER

7. 5. Measurements and Modelling of Convective Vaporization for Refrigerants in a Horizontal Tube

   Författare :Peter Melin; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; n-butane; HFC134a; pressure drop; propane; HFC143a; horizontal flow boiling; in-tube vaporization; HFC125; HFC32; experimental study; HCFC142b; HCFC22; non-azeotropic mixtures; CFC12; modelling; mixture effects;

   Sammanfattning : An evaporator facility has been constructed to measure local values of heat transfer and pressure drop. The evaporator resembles a normal working evaporator tube in a direct-expansion evaporator applicable to large heat pump/refrigeration cycles, typically over 500 kW. The evaporator is brine-heated and uses an expansion valve to control the inlet. LÄS MER