Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"Modelica"”.
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Languages and Tools for Optimization of Large-Scale Systems
… today. Dedicated computer languages, such as Modelica, and efficient software tools are available. In this thesis, an extension of Modelica, Optimica, targeted at dynamic optimization of Modelica models is proposed. In order to demonstrate the Optimica extension, supporting software has been …
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Development and modeling of a solar powered ground source heat pump system
… based object-oriented modeling language, i.e., Modelica [1] is being investigated for the integrated system modeling. Such dynamic model will be used to explore advanced control of a solar powered GSHP system to facilitate better building to grid integrations. The detail for the design and …
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Optimization of Low-Level Controllers and High-Level Polymer Grade Changes
… incentives for on-target production. Using the JModelica.org platform, several stationary operating points and dynamic grade changes are optimized with regards to economy. The optimizations are based on Modelica models of both a gas-phase polyethylene reactor and the polyethylene plant PE3 at …
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On Model Libraries for Thermo-hydraulic Applications
… written in general purpose modelling languages. Modelica(TM) is such an open standard for an object-oriented modelling language for dynamic systems. The thesis describes principles for object-oriented equation-based model libraries. The main topic is modelling of thermo-hydraulic applications. …
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Integrated System Architecture Development and Analysis Framework Applied to a District Cooling System
… SysML and the engineering analysis model using Modelica. The proposed framework supports system requirements verification activity. The analysis results show that the district chiller model developed using Modelica produces chilled water below 6.6 degrees Celsius, which satisfies the system …
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Dynamic analysis of an electrostatic energy harvesting system
… numerical model was implemented and tested using Modelica language. It was found that the efficiency of energy transfer strongly depends on three parameters: the ratio between the maximal electrical and mechanical energies in the system and ratio of natural frequencies of electric and mechanical …
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Dynamic modeling and control strategies for a micro-CSP plant with thermal storage powered by the Organic Rankine cycle
… plant, the dynamic model is implemented in the Modelica modeling language. Detailed steady-state component models, which are implemented in EES and validated to data where available, form the basis for the dynamic components. The dynamic model in its current form is used to make qualitative …
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Physical Modeling and Control of Low Temperature Combustion in Engines
… model of PPC was derived and implemented in the Modelica language. The model structure, a single-zone model, and implementation platform, JModelica.org, were chosen in order to allow for numerical optimization based on the model equations. The resulting framework allowed the calibration of the …
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Dynamic modeling of a steam Rankine Cycle for Concentrated Solar Power applications
… using the ThermoCycle library, written in the Modelica language. These models have been further interconnected to build the CSP plant model, whose response has been tested to fluctuating atmospheric conditions. The proposed library of models is based on an innovative lumped-parameter approach …
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Greenhouse Tomatoes: Process Simulation
… growing scenarios using the openly accessible Modelica Greenhouse Library in 10 select locations across the mainland USA. </p> <p>Two growing scenarios were explored, a base case without CO2 enrichment and a CO2+ case with a continuous flow of CO2 being externally supplied to the system. All …
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Modeling and Control of the Paper Machine Drying Section
… in the object-oriented modeling language Modelica. Two new approaches to control the moisture by feedback are evaluated. The first utilizes the air around the paper in combination with the drying cylinders to improve the controller performance. The second uses only the last part of the …
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TRANSIENT PERFORMANCE EVALUATION OF AUTOMOTIVE SECONDARY LOOP SYSTEMS
… reduced use of the vapor compression cycle. A Modelica model of the secondary loop system was developed and validated with experimental data. The model enables dynamic simulation of pull-down and drive cycle scenarios and was used to study the effects of coolant volume and coolant concentration …
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Improving the use of commercial building HVAC systems for electric grid ancillary services
… of a representative VAV system is built using Modelica and simulated to characterize the system's performance while providing reserve and regulation ancillary services. It is found that reserves are provided most effectively when airflow is reduced through the terminal units, while regulation …
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Dynamic Modeling and Model-Free Real-Time Optimization for Cold Climate Heat Pump Systems
… The proposed ESC strategies are evaluated with Modelica based dynamic simulation models of the three system configurations. Simulations have been conducted under both fixed and realistic ambient temperature profiles. The simulation results show good steady-state and transient performance of …