Sökning: "leakage cooling"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden leakage cooling.

1. 1. Heating and Cooling Requirements in Commercial Buildings. A duration curve model including building dynamics

   Författare :Per-Erik Nilsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVAC system; cooling requirements; duration curve; heating requirements; commercial building; heat balance; balance curve; energy analysis;

   Sammanfattning : In many European countries, especially, the heat loss due to transmission and air leakage, in many buildings today, is only a fraction of what it was in those built in the early 70's. At the same time there have been changes in the way the buildings are used which, among other things, has lead to an often considerable increase of the internal heat loads. LÄS MER

3. 2. Development of a non-destructive testing method for thermal assessment of a district heating network

   Författare :Peter Lidén; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shutdown; NDT; Copper wires; Cooling method; District heating pipes; Polyurethane;

   Sammanfattning : This thesis presents the development of a non-destructive testing (NDT)method for thermal assessment of pre-insulated district heating (DH) pipes with high accuracy, in which the development process from literature review to its present stage is presented and discussed. Pre-insulated DH pipes have been in use for more than 40 years. LÄS MER

4. 3. Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise

   Författare :David Martinez; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BEM; induction machine; noise prediction; vector control; acoustic noise; HEV; series magnetization; leakage reduction; thermal model; FEM; MEC; claw-poles; SMC; slip-ring-less machine; sound intensity measurements; vibration; Electrical engineering; Elektroteknik;

   Sammanfattning : This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines. In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. LÄS MER

5. 4. Process development of III-V-based infrared detectors

   Författare :David Ramos Santesmases; Per-Erik Hellström; Sanjay Krishna; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; infrared detectors; Type-II superlattice; surface leakage; high operating temperature; passivation; optical concentration; modulation transfer function; noise.; infraröda detektorer; Typ-II supergitter; ytströmmar; hög arbetstemperatur; passivering; optisk koncentration; moduleringsöverföringsfunktion; brus; Informations- och kommunikationsteknik; Information and Communication Technology;

   Sammanfattning : Type-II Superlattice (T2SL) detectors have revolutionized the field of infraredimaging, establishing themselves as the forefront technology in defense, space,and industrial applications. These detectors enable larger formats and higheroperating temperatures (HOT) that minimize the need for bulky and energyconsumingcryogenic cooling, paving the way for imaging systems with reducedSize, Weight, and Power (SWaP). LÄS MER

7. 5. Numerical Simulation of Some Heat Transfer and Fluid Flow Phenomena for Gas Turbine Blades and a Transonic Turbine Stage

   Författare :Fadil Mumic; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluiddynamik; plasma; Thermal engineering; applied thermodynamics; plasmas; Gaser; fluid dynamics; Gases; transonic; numerical; heat transfer coefficient; shroud surface; squealer blade tip; flat blade tip; leakage flow; Termisk teknik; termodynamik; turbulence modeling;

   Sammanfattning : With the attempts to achieve higher thermal efficiency, turbine blades are exposed to very high temperature gases and may undergo severe thermal stress and fatigue. Thus, in order to develop optimal cooling strategies and reduce the heat transfer it is important to obtain a good understanding of both the complex flow field and the heat transfer characteristics in turbine rotor/stator hot-gas passages. LÄS MER