Search for dissertations about: "micro channel heat transfer"

Showing result 1 - 5 of 8 swedish dissertations containing the words micro channel heat transfer.

  1. 1. Experimental Heat Transfer, pressure drop, and Flow Visualization of R-134a in Vertical Mini/Micro Tubes

    University dissertation from Stockholm : KTH

    Author : Wahib Owhaib; KTH.; [2007]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Minichannel; microchannel; heat transfer; pressure drop; single-phase; two-phase; flow boiling; flow visualization; dry out; bubble behavior; flow pattern.; TECHNOLOGY Engineering mechanics Mechanical and thermal engineering Mechanical energy engineering; TEKNIKVETENSKAP Teknisk mekanik Mekanisk och termisk energiteknik Mekanisk energiteknik;

    Abstract : For the application of minichannel heat exchangers, it is necessary to have accurate design tools for predicting heat transfer and pressure drop. Until recently, this type of heat exchangers was not well studied, and in the scientific literature there were large discrepancies between results reported by different investigators. READ MORE

  2. 2. Flow boiling heat transfer, pressure drop and dryout characteristics of low GWP refrigerants in a vertical mini-channel

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Zahid Anwar; KTH.; [2014]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mini micro-channels; R1234yf; R152a; R600a; R134a; Boiling heat transfer; Pressure drop; Dryout; Correlation;

    Abstract : Two-phase heat transfer in mini/micro-channels is capable of meeting the high cooling demands of modern high heat flux applications. The phase change process ensures better temperature uniformity and control for local hot spots. Furthermore, these compact channels could be helpful in reducing the required charge and material inventories. READ MORE

  3. 3. Numerical study of flow boiling in micro/mini channels

    University dissertation from KTH Royal Institute of Technology

    Author : Qingming Liu; KTH.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical; boiling; micro channel; phase change.; Energiteknik; Energy Technology;

    Abstract : Boiling phenomena in micro scale has emerged as an interesting topic due to its complexity and increasing usage in micro electronic and mechanical systems (MEMS). Experimental visualization has discovered five main flow regimes: nucleate boiling, isolated bubbles, confine bubbly flow, elongated bubbly (or slug) flow, and annular flow. READ MORE

  4. 4. Enhanced Boiling Heat Transfer on a Dendritic and Micro-Porous Copper Structure

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Richard Furberg; KTH.; [2011]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; enhanced boiling; R134a; FC-72; flow boiling; heat transfer; high speed visualization; instability; micro-channels; micro-structured; nano- and micro-technology; nano- and micro-porous structured surfaces; plate heat exchanger; pool boiling; porous media; thermosyphon; two-phase heat transfer; SRA - Energy; SRA - Energi;

    Abstract : A novel surface structure comprising dendritically ordered nano-particles of copper was developed during the duration of this thesis research project. A high current density electrodeposition process, where hydrogen bubbles functioned as a dynamic mask for the materials deposition, was used as a basic fabrication method. READ MORE

  5. 5. Flow boiling of ammonia and propane in mini channels

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Muhammad Hamayun Maqbool; KTH.; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow Boiling; Mini channels; Global Warming Potential; Ammonia; Propane; R134a; HFC; Two-phase; Heat Transfer; Pressure Drop; Dry out.;

    Abstract : The environmental concerns in recent times have grown especially after signing Montreal protocol. In the last ten years, researchers have focussed mainly on understanding the boiling and condensation phenomena of HFC refrigerants in minichannels. READ MORE