Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

Browse

Filters

2015 - 20182

Settings

Subject: search.filters.subject.Simulink

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    SysML Executable Model of an Energy Efficient House and Trade-Off Analysis
    (2018) Cawasji, Kersasp Aspi; Baras, John S.; Systems Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    With the growing complexity of energy efficient buildings, the methods of modeling and simulating such structures must account for monitoring several thousand design parameters across multiple diverse domains. As a result, modeling tools are now very specific to their respective domains and are growing more and more incongruous with each other. This calls for a way to integrate multiple modeling tools in the effort to create a single, large model capable to encapsulate data from multiple, different models. Thus, in this thesis, different methods to perform an integration with Systems Modeling Language (SysML) and a simulation tool were identified, described and evaluated. Then, a new method was developed and discussed. Finally, the new method was demonstrated by developing a SysML executable model of a simple two-room house that utilizes solar power for space heating, with a heat pump used as a backup. Using the Functional Mock-up Interface (FMI) standard, the SysML model is integrated with a Modelica model, and a simulation is run in Simulink. Finally, a tradeoff analysis was performed for the purpose of design space exploration.
  • Thumbnail Image
    Item
    Dynamic Modeling of Vapor Compression Systems for Residential Heat Pump Applications with Alternative Low-GWP Refrigerants
    (2015) Bhanot, Viren; Hwang, Yunho; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    With the increased focus on reducing greenhouse gas emissions, low-GWP refrigerants, R32 and D2Y60, have been proposed as drop-in replacements for R410A in residential heat pumps. This thesis presents the development of a modeling framework in Simulink® for the dynamic simulations of such residential heat pumps. The framework is component-based, allowing arbitrary cycle configurations, and includes most of the relevant components. Finite-volume method has been applied to the heat exchanger. Compression and expansion processes are treated as quasi-steady state. The framework has been used to study the performance of the system using the baseline refrigerant and charge-optimized alternatives at ASHRAE test conditions, and the results have been compared against experimental data. Steady-state COP values fall within ±8% of experimental data. For the cyclic tests, the pressure and temperature behaviors compare well and accumulated capacity and power consumption errors are found to be within ±9%. Relative differences between the refrigerants are consistent between simulations and measurements. The framework shows potential for being used to simulate the operation of residential heat pumps under dynamic conditions.