5,355 research outputs found

    Software architecture for web-accessible heat exchanger experiment

    Get PDF
    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.Includes bibliographical references (leaf 110).Web-accessible laboratory experiments are gaining popularity due to their advantages over traditional laboratory experiments. With advancement in internet technology, more and more laboratories are becoming web-accessible. The needs for these virtual labs fit perfectly into the modern methods of assembly, delivery and access to educational technology resources adopted by educational institutions around the world. But still there is an absence of proper standards as to how to properly design and deal with the software infrastructure issues that make it possible for the labs to be accessible through web. It is always necessary to design a software system that is robust, platform independent and easily modifiable to accommodate changing requirements. It is also necessary for the system to be easily replicable for newer labs. The software architecture for the MIT I-Lab Heat Exchanger experiment is designed keeping in mind all these needs and it has been modified at different times to make room for changing requirements both in part of students performing the experiment (through student assessment of the experiment) and the instructors of the courses that the system has been deployed to. The design and implementation of the software architecture for the heat exchanger experiment is discussed in this thesis. The key component of the system is a Laboratory Heat Exchanger, which is employed to study principles of heat transfer. The software system is divided into four functional components: local server control of the laboratory equipment, remote client control of the equipment, client collaboration and user registration, authentication and experiment scheduling. The system has been successfully used in three MIT courses and one course at University of Texas at Austin over the span of two semesters and is scheduled to be used in two more courses in addition to these. With evolution of newer and better technology, the system will be able to accommodate itself to suitable changes that conform to the requirements of the system and always thrive to provide a more robust solution to the problems at hand.by Rubaiyat Amin Khan.S.M

    Sub-hourly simulation of residential ground coupled heat pump systems

    Get PDF
    Residential Ground Coupled Heat Pump systems are usually characterised by an ON/OFF behaviour of the heat pump with typical cycling frequencies of 1 - 4 cycles per hour. The ground loop fluid pump has the same ON/OFF behaviour and the borehole heat exchanger operates either in full flow or no flow conditions. Typical hourly simulations of GCHP systems use steady-state models for the heat pump and the borehole fluid (transient models being used for buildings and heat transfer in the ground). This paper reviews the models used in typical hourly simulations as well as transient models that are available and compares the results obtained using the two classes of models within the TRNSYS simulation environment. Both the long-term energy performance and the optimum system design are compared. It is shown that using steady-state models leads to an overestimation of the energy use that ranges from a few percents with oversized borehole heat exchangers to 75% for undersized exchangers. A simple Life Cycle Cost analysis shows that using steady-state models can lead to selecting a very different design than the one that would have been selected using dynamic models

    Introducing instrumentation and data acquisition to mechanical engineering students using LabVIEW

    Get PDF
    For several years, LabVIEW has been used within the Department of Mechanical Engineering at the University of Strathclyde as the basis for introducing the basic concepts and practice of data acquisition, and more generally, instrumentation, to postgraduate engineering students and undergraduate project students. The objectives of introducing LabVIEW within the curriculum were to expose students to instrumentation and experimental analysis, and to create courseware that could be used flexibly for a range of students. It was also important that staff time for laboratory work be kept to manageable levels. A course module was developed which allows engineering students with very little or no previous knowledge of instrumentation or programming to become acquainted with the basics of programming, experimentation and data acquisition. The basic course structure has been used to teach both undergraduates and postgraduates as well as laboratory technical staff. The paper describes the objectives of the use of LabVIEW for teaching, the structure of the module developed, and the response of students who have been subjected to the course, and how it is intended to expand the delivery to greater student numbers

    Transient thermal analysis of a data centre cooling system under fault conditions

    Get PDF
    Data centres housing the IT infrastructure of large organisations constitute a considerable technical challenge to ensure 100% operational availability for mission critical IT systems. Specifying plant cooling systems to maintain suitable temperature levels and dissipate the heat generated can be carried out using industry standard design methods. However, accounting for perturbations in cooling due to failure of plant and restart of backup systems requires for faster thermal transients to be addressed than would normally be encountered in building system analysis. It is in this context that this paper describes the modelling and analysis of a 5 MW chilled water cooling system used for the cooling of a recently constructed UK data centre. The model has been developed using the TRNSYS software and includes a full model of the energy transfers for the data centre including chillers, hydraulic network, valve models and each of the 70 Room Air Conditioning Units. The coupling between the data centre air temperature levels and the cooler system has enabled a full assessment of the cooling system design in response to system perturbations. A number of scenarios are examined involving the failure of the chillers and how the inherent thermal inertia of the system plus additional inertia achieved through buffer vessels allowed a suitable design to be achieved. The detailed transient analysis model allowed the sizing of these vessels effectively and to gain a better understanding of the chilled water plant operation, both in normal conditions and in the case of failure

    Specifications for modelling fuel cell and combustion-based residential cogeneration device within whole-building simulation programs

    Get PDF
    This document contains the specifications for a series of residential cogeneration device models developed within IEA/ECBCS Annex 42. The devices covered are: solid oxide and polymer exchange membrane fuel cells (SOFC and PEM), and internal combustion and Stirling engine units (ICE and SE). These models have been developed for use within whole-building simulation programs and one or more of the models described herein have been integrated into the following simulation packages: ESP-r, EnergyPlus, TRNSYS and IDA-ICE. The models have been designed to predict the energy performance of cogeneration devices when integrated into a residential building (dwelling). The models account for thermal performance (dynamic thermal performance in the case of the combustion engine models), electrochemical and combustion reactions where appropriate, along with electrical power output. All of the devices are modelled at levels of detail appropriate for whole-building simulation tools

    Remote administration and user experience evaluation of the iLab Heat Transfer Project site

    Get PDF
    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references.The iLab Heat Transfer Project provides a means for students to remotely execute, via a web interface, experiments related to the topic of heat transfer. The website associated with this project provides instructors with the ability to remotely manage the performance of experiments by their students. This thesis describes improvements made to this website that are intended to grant more control to instructors. Specifically, the website has been augmented to provide remote instructors with complete control over experiment scheduling, user registration, document uploading, and other relevant administrative tasks. The interfaces by which users perform experiments have been modified to incorporate an audio and video feed of the laboratory equipment used in these experiments. In addition, the website has been extended with a feature that facilitates the viewing and analysis of questionnaire responses collected from students. The questionnaire responses provided by students have been examined to gain more knowledge about the effectiveness of various aspects of the website and experiment interfaces.by Rodney K. Graham.M.Eng

    Series of experiments for empirical validation of solar gain modelling in building energy simulation codes - experimental setup, test cell characterization, specifications and uncertainty analysis

    Get PDF
    Empirical validation of building energy simulation codes is an important component in understanding the capacity and limitations of the software. Within the framework of Task 34/Annex 43 of the International Energy Agency (IEA), a series of experiments was performed in an outdoor test cell. The objective of these experiments was to provide a high-quality data set for code developers and modelers to validate their solar gain models for windows with and without shading devices. A description of the necessary specifications for modeling these experiments is provided in this paper, which includes information about the test site location, experimental setup, geometrical and thermophysical cell properties including estimated uncertainties. Computed overall thermal cell properties were confirmed by conducting a steady-state experiment without solar gains. A transient experiment, also without solar gains, and corresponding simulations from four different building energy simulation codes showed that the provided specifications result in accurate thermal cell modeling. A good foundation for the following experiments with solar gains was therefore accomplished

    Linkage between knowledge management practices towards library user’s satisfaction at Malaysian University Libraries

    Get PDF
    Academic library services have begun to apply various knowledge management (KM) practices in the provision of library services. KM has been developed to enhance the use of organizational knowledge through practices and organizational learning. KM practices include the creation, capture and/or acquisition of knowledge, its retention and organization, its dissemination and re-use, and general responsiveness to the new knowledge. The focus of this research is the assessment of KM practices, particularly creation, acquisition, capture, sharing, recording and preservation, and their effects on Library User’s Satisfaction (LUS) in Malaysian university libraries. The objective of this research is the development of a model to enhance KM processes (i.e. Creation, acquisition, capturing, sharing, recording, and preserving) and to improve library users’ satisfaction. A quantitative approach in research methodology is employed (e.g. Questionnaire) for the purpose of generating new knowledge and understanding of library concerns. The findings of this research show that the overall KM practice at six Malaysian university libraries is at a high level. The findings from the structural model indicated that two KM processes, namely knowledge creation and acquisition, are not supported in terms of KM practices at Malaysian university libraries. Other KM processes, namely capturing, sharing, recording, and preserving are fully supported towards KM practices in the library. Hence, the major contribution of this research is a model, namely KM Practice-Library User’s Satisfaction (KMP-LUS) highlighting six KM processes based on strong Structural Equation Modeling (SEM) fit indices

    A modern teaching environment for process automation

    Get PDF
    Emergence of the new technological trends such as Open Platform Communications Unified Architecture (OPC UA), Industrial Ethernet, cloud computing and the 5th wireless network (5G) enabled the implementation of Cyber-physical System (CPS) with flexible, configurable, scalable and interoperable business models. This provides new opportunities for the process automation systems. On the other hand, the constant urge of industries for cost and material efficient processes demands a new automation paradigm with the latest tools and technologies which should be taken into account while teaching future automation engineers. In this thesis, the modern teaching environment for process automation is designed, implemented and described. This work explains the connections, configurations and the test of three mini plants including the Multiple Heat Exchanger, the Three-tank system and the Mixing Tank. In addition, OPC UA communication between the server and its clients has been tested. The plants are a part of the state of the art of the architecture that provides the access of ABB 800xA to the cloud services via OPC UA over the 5G test wireless network. This new paradigm changes the old automation hierarchy and enables the cross layered communication in the old architecture. This modern teaching environment prepares the students for the future automation challenges with the latest tools and merges data analytics, cloud computing and wireless network studies with process automation. It also provides the unique chance of testing the future trends together in this unique process automation setup
    • …
    corecore