Sökning: "transient operation"

Visar resultat 1 - 5 av 136 avhandlingar innehållade orden transient operation.

1. 1. Simplified models for emission formation in diesel engines during transient operation

   Författare :Anders Westlund; Hans-Erik Ångström; Martti Larmi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diesel engine; emission modeling; transient operation; NOx; Soot; Mechanical energy engineering; Mekanisk energiteknik;

   Sammanfattning : The work presented in this thesis is the result of the KTH CICERO project “Dynamic Engine Performance” in which the main objective was to develop simple models foremission formation. The demand for such models is increasing, mainly due to the tightening emission legislation for diesel engines which has lead to more complex engines and thereby more laborious development and calibration processes. LÄS MER

3. 2. Transient Phenomena in CO and Hydrocarbon Oxidation over Supported Platinum Catalysts

   Författare :Per-Anders Carlsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mean-field kinetics simulations; ignition; environmental heterogeneous catalysis; flow-reactor studies; periodic operation; extinction; low-temperature activity; transient methods; in situ spectroscopy;

   Sammanfattning : The aim with this thesis work was to better understand transient phenomena involved in the low-temperature oxidation of CO and hydrocarbons by oxygen over typical oxidation catalysts. Supported platinum catalysts were prepared and carefully studied under transient conditions by means of flow-reactor experiments, different in situ spectroscopic (FTIR and XANES) methods in combination with mass spectrometry and mean-field kinetics simulations. LÄS MER

4. 3. FLOW FIELD IN A HIGH HEAD FRANCIS TURBINE DRAFT TUBE DURING TRANSIENT OPERATIONS

   Författare :Rahul Goyal; Michel J. Cervantes; Bhupendra K. Gandhi; Gabriel Ciocan; Lisa Prahl; Ramis Orlu; Gunilla Andree; Andrea Toffolo; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Francis turbine; Steady state; Transient; Particle Image Velocimetry; Vortex Rope; Strömningslära; Fluid Mechanics;

   Sammanfattning : Hydroelectricity plays an important role to balance the stability of grid network.  In order to improve the stability of presently high loaded grids, hydropower plants are being operated over a wide range of operations and experiencing frequent start-stop, load rejection, and load acceptance. LÄS MER

5. 4. Evaluation of a Variable Nozzle Turbine Turbocharger on a Diesel Engine under Steady and Transient Conditions

   Författare :Ralf Barkhage; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; diesel engine; emissions; transient operation; control system; fuel economy; variable geometry turbocharging; engine performance; variable nozzle turbine; supercharging;

   Sammanfattning : The growing global call for reduced emissions and fuel consumption together with the market call for engines with higher power density and application-oriented torque curves can be met using turbochargers with variable geometry turbines (VGT). The second generation of VGT turbochargers is currently being developed and is starting to appear on the market. LÄS MER

7. 5. Steam Turbine Thermal Modeling for Improved Transient Operation

   Författare :Monika Topel; Björn Laumert; Konstantinos Kyprianidis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; steam turbines; transients; start-up; finite element model; heat transfer; Energy Technology; Energiteknik;

   Sammanfattning : The growing shares of renewable energy sources in the market and solar thermal power applications have set higher requirements on steam turbine operation.These requirements are related to flexibility during transients. A key aspect sought of such flexibility is the capability for fast starts. LÄS MER