Sökning: "heat pumps"

Visar resultat 1 - 5 av 78 avhandlingar innehållade orden heat pumps.

1. 1. Integrated Control of Heat Pumps

   Författare :Fredrik Karlsson; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable speed compressor; superheat; electronic expansion valve; optimisation; performance indication; control; heat pump; energy efficiency;

   Sammanfattning : The purpose of the work presented in this thesis is to investigate the potential and prerequisites for improved energy efficiency of heat pump systems using efficient components and proper methods for optimisation of operation. The background is that several investigations have reported on possibilities for increased energy efficiency of heat pumps if variable-speed capacity control is used instead of conventional on/off control. LÄS MER

3. 2. Propane as refrigerant in residential heat pumps

   Författare :Olivier Pelletier; KTH; []
   Nyckelord :Propane; Refrigerants; Heat pumps;

   Sammanfattning : .... LÄS MER

4. 3. A Silent Revolution : The Swedish Transition towards Heat Pumps, 1970-2015

   Författare :Petter Johansson; Pär Blomkvist; Martin Vendel; Eric Giertz; Mats Fridlund; KTH; []
   Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; heat pumps; socio-technical transition; sustainability transition; industrial dynamics; value networks; coopetition; complementarities; strategic management; värmepumpar; socio-tekniska övergångar; hållbarhet; industriell dynamik; värdenätverk; coopetition; komplementariteter; företagsstrategi; Industrial Economics and Management; Industriell ekonomi och organisation;

   Sammanfattning : Currently, more than half of all Swedish single-family houses have an installed heat pump and more heat is supplied by heat pumps in Sweden than in any other nation. Despite the enormous impact of heat pumps on the Swedish energy system, the transition towards their use has gone relatively unnoticed. LÄS MER

5. 4. Flow Boiling Heat Transfer in Single Vertical Channels of Small Diameter

   Författare :Claudi Martin Callizo; Björn Palm; Predrag Hrnjak; KTH; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microchannel; heat exchanger; heat transfer; flow boiling; flow patterns; onset of nucleate boiling; dryout; critical heat flux; Mechanical and thermal engineering; Mekanisk och termisk energiteknik;

   Sammanfattning : Microchannel heat exchangers present many advantages, such as reduced size, high thermal efficiency and low fluid inventory; and are increasingly being used for heat transfer in a wide variety of applications including heat pumps, automotive air conditioners and for cooling of electronics.However, the fundamentals of fluid flow and heat transfer in microscalegeometries are not yet fully understood. LÄS MER

7. 5. Solar Colletors Combined with Ground-Source Heat Pumps in Dwellings - Analyses of System Performance

   Författare :Elisabeth Kjellsson; Avdelningen för Byggnadsfysik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heating in dwellings; TRNSYS simulations; solar collectors; ground-source heat pumps; ground heat;

   Sammanfattning : The use of ground-source heat pumps for heating buildings and domestic hot water in dwellings is increasing rapidly in Sweden. The heat pump extracts heat from the ground by a U-pipe in a vertical borehole. In order to reduce the electricity demand in the system, the combination with solar collectors is introduced. LÄS MER