Sökning: "heat pipe"

Visar resultat 16 - 20 av 65 avhandlingar innehållade orden heat pipe.

1. 16. Thermal response tests : influence of convective flow in groundwater filled borehole heat exchanger

   Författare :Anna-Maria Gustafsson; Jeffrey D. Spitler; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vattenteknik; Water Resources Engineering; VA-teknik; Urban Water Engineering;

   Sammanfattning : The main objective of this doctorial thesis was to investigate how thermally induced movements in the groundwater (natural convective flow) may influence the heat transport in borehole and surrounding bedrock in a groundwater filled borehole heat exchanger system. The purpose was also to determine if thermal response tests could be used to detect the convective influence and the effect on evaluated heat transfer parameters, effective bedrock thermal conductivity and borehole thermal resistance. LÄS MER

3. 17. Development of a non-destructive field testing method for thermal assessment of district heating pipes

   Författare :Peter Lidén; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat losses; thermal status; valve; polyurethane; cooling method; non-destructive testing; thermal conductivity; district heating network;

   Sammanfattning : The thermal state of a district heating (DH) network governs the heat losses. It is a parameter considered if a change is to be made in the network. Heat losses are costly and economic aspects are important when planning for the maintenance or replacement of DH pipes. LÄS MER

4. 18. Thermophysical Properties of Aqueous Solutions Used as Secondary Working Fluids

   Författare :Åke Melinder; Björn Palm; Antero Aittomäki; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Secondary working fluids; secondary refrigerants; indirect systems; aqueous solutions; ice slurry; thermophysical properties; freezing point; density; viscosity; specific heat; thermal conductivity; Mechanical and thermal engineering; Mekanisk och termisk energiteknik;

   Sammanfattning : Secondary working fluids (secondary refrigerants, heat transfer fluids, antifreezes, brines) have long been used in various indirect re-frigeration and heat pump systems. Aqueous solutions (water solu-tions) have long been used as single phase (liquid only) secondary working fluids for cooling in supermarkets, ice rinks, heat recovery systems, heat pumps and other applications. LÄS MER

5. 19. Large Eddy Simulation of Impinging Jets

   Författare :Thomas Hällqvist; Laszlo Fuchs; Pierre Sagaut; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Impinging jet; large eddy simulation; heat transfer; vortex formation; circular jet; forcing; inflow conditions; implicit modeling.; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : This thesis deals with Large Eddy Simulation (LES) of impinging air jets. The impinging jet configuration features heated circular jets impinging onto a flat plate. The problem addressed here is of generic nature, with applications in many engineering devices, such as cooling of components in gas turbines, in cars and electronic devices. LÄS MER

7. 20. District heating system analysis and challenges within the urban transformation of Kiruna

   Författare :Mattias Vesterlund; Jan Dahl; Henrik Saxen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District heating; analysis; optimization; design; heat production; Energy Engineering; Energiteknik;

   Sammanfattning : There is currently an ongoing urban transformation in a small Swedish town named Kiruna, it is located in the very north of Sweden well above the Arctic Circle in a sub-arctic climate. Large part of the town will be relocated due to the ground deformation that is caused by the progressing iron ore mining activity and it is affecting all infrastructures of the town. LÄS MER