TTU Published Journals @ Volpe Library
Not a member yet
971 research outputs found
Sort by
Performance Analysis and Optimization of a Dual-Source Heat Pump System: Evaluating Bivalent Point Strategies for Enhanced Efficiency
Get PDFThis study presents a comprehensive performance analysis and optimization framework for a dual-source heat pump (DSHP) system integrating Air Source Heat Pumps (ASHP), Ground Source Heat Pumps (GSHP), and Parallel Source Heat Pumps (PSHP). A MATLAB–Simulink model, developed using the CARNOT toolbox, simulates various configurations to identify optimal operational strategies. Results show that hybrid operation improves the Annual Performance Factor (APF) by approximately 5 % compared to a standalone GSHP system and allows a reduction in borehole depth by ~28 % (from 70 m to 50 m) while maintaining stable brine temperatures. The optimized bivalent switching (ASHP > 0 °C; GSHP < 0 °C down to –10 °C) minimizes temperature lift and enhances thermal balance in the ground loop. The findings highlight the importance of coordinated source management for achieving higher energy efficiency and long-term stability in hybrid heat pump systems
Predicting Energy Consumption in Buildings Using Various Artificial Intelligence Models
Get PDFAccurately predicting energy consumption in buildings is vital for optimizing energy efficiency, reducing costs, and supporting sustainability efforts. This study uses a dataset that spans and broadcasts hourly energy consumption for a specific building in Spain, using a dataset spanning an entire year. The dataset includes hourly energy usage in kilowatt-hours (kWh) and features representing environmental conditions, including temperature, humidity, and precipitation. alongside time-related variables, including the hour of the day, day of the week, and seasonal markers. These features provide a detailed view of how internal and external conditions influence energy usage patterns. Data preprocessing included handling missing values, feature selection, and engineering temporal variables such as Hour, Day of Year, and Is Weekend, which capture essential behavioral and operational dynamics. The building analyzed is a representative structure with typical heating, ventilation, and air conditioning (HVAC) systems. This model is well-suited for analyzing energy consumption patterns across different environmental and operational conditions. Various regression models were applied, including Linear Regression, Ridge and Lasso Regression, Support Vector Regression (SVR), K-Nearest Neighbors (KNN), Random Forest, XGBoost, and Neural Networks. Model performance was assessed using Mean Absolute Error (MAE) and R-squared (R²) metrics. Random Forest emerged as the best-performing model, achieving an MAE of 8.33 and an R² of 0.954, highlighting its strong ability to capture the building’s energy consumption patterns. This research highlights the potential of regression models and artificial intelligence in improving energy forecasting, serving as a foundation for advancing building energy management systems
The Effect of SiO2 Nanoparticle on the Mechanical Properties of Silica-Epoxy Nanocomposites-An Experimental Study: Nanoparticles in Silica-Epoxy Nanocomposites
No full textPolymer nanocomposites, featuring reinforcing particles smaller than 100 nm, exhibit superior mechanical properties compared to conventional composites. This study investigates the effect of nanoparticle size and weight fraction on the Young’s modulus and tensile strength of epoxy-silica nanocomposites. To evaluate their mechanical behavior, epoxy-silica samples were prepared using nanoparticles sized 15 nm, 20 nm, and 80 nm at 3% and 5% weight fractions. Ultimate stress, yield stress (0.2%), maximum strain, and Young’s modulus were measured. Results showed that adding silica nanoparticles enhanced the ultimate tensile stress, yield stress, and Young’s modulus of pure epoxy. Notably, nanocomposites with 80 nm particles at 3% loading displayed the highest strain. At 5% loading, 20 nm nanoparticles exhibited the highest tensile strength and stiffness among the tested samples, while 15 nm particles showed comparatively lower improvements, likely due to increased agglomeration. Additionally, a general trend of increased stiffness was observed with smaller particle sizes, although deviations occurred due to dispersion and porosity effects
Effects of Uncertainty on the Prediction of Energy Consumption of Compressed Air Systems
Get PDFCompressed air is an essential part of operations at many industrial and manufacturing plants. For example, compressed air can be used for stamping, clamping, driving power tools, cleaning tools, and powering controls or actuators. Simulink is used to model a continuously operating compressed air system, aftercooler, and heat-rejection system. The three main sources of energy consumed by the system include the energy consumed by the air compressor’s motor, the energy consumed by the aftercooler’s pump, and the energy consumed by the heat-rejection system’s fan motor. Testing agencies test equipment per a standard and document performance results. Regulatory-governmental-agencies select a testing standard and a minimum performance rating. Regulatory agencies allow the manufacturers to advertise and sell their products if, during testing, product performance stays within an allowable tolerance. A typical acceptable tolerance for compressor airflow is between ± 4% and ± 7%, depending on the compressor’s capacity, meanwhile, according to the ASHRAE 90.1, section G, the typical acceptable tolerance for the pump’s waterflow rate is ± 5% of its rated value. Finally, the acceptable fan tolerance is between ± 3% and ± 5% of its rated value. Also, all other equipment in the plant has its own designated tolerances. These tolerances introduce uncertainty in predicting the overall system’s energy consumption. The authors have used the compressor airflow’s allowable tolerance in their compressed air model to evaluate the effects of this uncertainty on a compressed air system’s predicted yearly energy consumption
Design and Optimization of a Lab-Scale System for Efficient Green Hydrogen Production Using Solar Energy
Get PDFThis paper presents the design and optimization of a novel lab-scale green hydrogen production system driven by solar photovoltaic (PV) energy. The primary focus is to enhance the efficiency of hydrogen production by addressing key challenges in electrical integration and power electronics. To achieve minimal power losses and maintain voltage and current levels within optimal operating parameters, advanced energy conversion techniques have been implemented. The system incorporates real-time control to dynamically synchronize PV output with electrolyzer requirements, maximizing production efficiency.
Experimental results show that the system achieves a hydrogen production rate of up to 3.0 liters over 10 minutes at an optimal operating current range of 1.0–2.5 A, and an input voltage range of 4.5–7.5 V. Compared to conventional systems, the setup demonstrated an 18% reduction in power losses and a 25% improvement in operational stability under fluctuating irradiance conditions. The integration of battery storage and a solar emulator further supports consistent performance, making the system a promising model for scalable, renewable hydrogen generation. While this work primarily evaluates hydrogen production, oxygen was also generated in a 2:1 molar ratio and released, with future work aimed at capturing and utilizing this byproduct
Letter to the Editor
Get PDFThis letter gives many characteristics of a high quality company wide energy management program
Design of a Remotely Operated Hydraulic Transmission Vehicle: Source: Journal of Engineering Technology, Spring 2022, Volume 39 Issue 1, pg. 14-26
No full textThis work presents the design of a mote-controlled with a hydraulically powered transmission for use as a supplementary tool to help teach complex concepts in engineering courses. The lack of fluid power demonstrators in higher education was the main driving factor in the development of this vehicle. The portable demonstrator consists of three main subsystems: the structural, electrical, and hydraulic systems. The vehicle's open-chassis design allows the electrical and hydraulic system to be visually exposed to understand how the vehicle works. Electrical servo motors, an electric speed controller, and communication devices make up the electrical circuit that controls the vehicle via a handheld remote. The electrical system is used to power and control the hydraulic system, which transmits power to the vehicle's wheels. A solenoid directional control valve is used to alter flow between the hydraulic pump and motor, controlling the speed and direction of the vehicle. The hydraulic transmission transfers the rotational energy from an electric prime mover into mechanical energy stored in the fluid. This energy is then converted to rotational energy using a hydraulic motor and is delivered to the vehicle's driveshaft. The vehicle's mechanical systems provide a tangible illustration of the basic principles found in courses such as fluid power, fluid mechanics, hydraulic motion control, and machine design. The electronic systems used to control the vehicle demonstrate fundamental concepts taught in courses such as electrical circuits, electronics, signals, and systems.
Full text available at https://ezproxy.tntech.edu/login?url=https://www.proquest.com/scholarly-journals/design-remotely-operated-hydraulic-transmission/docview/2677669486/se-2?accountid=2883
Dual Analysis of Rigidity for Structural Analysis Course: Source: Journal of Engineering Technology, Fall 2022, Volume 39 Issue 2, pg. 8-24
No full textThis paper establishes comprehensible and practicable expressions using matrix for the equilibrium and geometry methods for structural rigidity analysis. A rigorous definition of structural rigidity is presented using the concept of differential for the geometric method. The dual relationship is proved between the equilibrium and geometry methods, which provides a theoretical base for the option of choosing an easier approach in different scenarios. Duality of equilibrium and geometric approaches is further investigated for the three-rigid-disc systems with fictitious hinges, which demonstrates the advantages of the two methods varying in different cases. In addition, Hennebergs method, which was originally developed to solve complex trusses, is introduced for rigidity analysis when the system is too complex for the triangular rule to be applied. Theoretical proof using notations of matrix is presented, and an example of truss is given to show the effectiveness of Hennebergs method for rigidity analysis. Two examples in practice, one of which is a special damper for structural vibration control and the other about displacement sensing for large-scale testing, are provided to show applications of rigidity analysis. Finally, suggestions are provided for teaching rigidity analysis with the duality of the equilibrium and geometry approaches in structural analysis course.
Full text available at https://ezproxy.tntech.edu/login?url=https://www.proquest.com/scholarly-journals/dual-analysis-rigidity-structural-course/docview/2748511594/se-2?accountid=2883
What Is a Professional? Source: Journal of Engineering Technology, Spring 2022, Volume 39 Issue 1, pg. 8-13
No full textDefinitions of technical terms are important in any field. In a class on professional ethics, two words require explanation-"professional" and "ethics"- to facilitate common understanding and inform discussion. This paper first focuses on the meaning of "professional," according to available literature and then describes a classroom exercise intended to promote clarity and comprehension, since most students are unfamiliar with a field-specific definition of that word.
Full text available at https://ezproxy.tntech.edu/login?url=https://www.proquest.com/scholarly-journals/what-is-professional/docview/2677667670/se-2?accountid=28833
A Case Study for Integration of Teaching and Research in an Engineering Technology Program: Source: Journal of Engineering Technology, Spring 2022, Volume 39 Issue 1, pg. 30-40
No full textIn recent years, some engineering technology programs are expecting their faculty members to conduct more research. The challenge for these faculty to strike a balance between teaching and research is unique since they tend to have much higher teaching loads than faculty members in traditional engineering programs. One of the solutions to this challenge is to integrate research and teaching. This paper discusses a case study where a research project, a capstone project, and a course project were seamlessly integrated in an engineering technology program. The positive impacts on faculty members' teaching and research and students' learning were reflected in a student survey, an external assessment, the success of a capstone project, and relevant publications. The effort of integrating teaching and research made faculty members' research more productive and students more engaged in their learning.
Full text available at https://ezproxy.tntech.edu/login?url=https://www.proquest.com/scholarly-journals/case-study-integration-teaching-research/docview/2677665435/se-2?accountid=2883