Performance of Thermoactive Foundations for Commercial Buildings

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Byung Chang Kwag ◽  
Moncef Krarti
Keyword(s):  
Numerical Solution ◽  
Thermal Performance ◽  
Energy Use ◽  
Three Dimensional ◽  
Thermal Response ◽  
Building Energy ◽  
Commercial Buildings ◽  
Response Factors ◽  
Foundation Pile ◽  
The Impact

A transient three-dimensional numerical solution is developed to analyze the thermal performance of thermo-active foundations used to heat and cool commercial buildings. Using laboratory testing data, the numerical solution is validated and used to carry out a sensitivity analysis to assess the most important design and operating parameters that affect the thermal performance of thermo-active foundations. It is found that the foundation depth, the shank space, the fluid flow rate, and the number of U-tube loops in each foundation pile are the main parameters that affect the thermal performance of a thermo-active foundation system. Based on the validated numerical solution, thermal response factors for a thermo-active foundation are developed, and implemented into a detailed building energy simulation program. These thermal response factors are then used to estimate the impact of installing thermo-active foundations on the total energy use of typical office buildings in representative US climates.

Performance of Thermoactive Foundations for Commercial Buildings

2012 ◽  
Author(s):  
Byung Chang Kwag ◽  
Moncef Krarti
Keyword(s):  
Numerical Model ◽  
Energy Use ◽  
Three Dimensional ◽  
Thermal Response ◽  
Building Energy ◽  
Commercial Buildings ◽  
Response Factors ◽  
Testing Data ◽  
Foundation Pile ◽  
The Impact

A transient three-dimensional numerical model is developed to model the performance of thermoactive foundations used to heat and cool commercial buildings. Using laboratory testing data, the numerical model is validated and used to carry out a sensitivity analysis to assess the most important design and operating parameters that affect the performance of thermoactive foundations. It is found that the foundation depth, the shank space, the fluid flow rate, and the number of U-tube loops in each foundation pile are the main parameters that affect the thermal performance of a thermoactive foundation system. Based on the validated numerical model, thermal response factors for a thermoactive foundation are developed, and implemented into a detailed building energy simulation program. These thermal-response factors are then used to estimate the impact of installing thermoactive foundations on the total energy use of typical office buildings in various US climates.

Development of a Response Factor Model for Thermo-Active Building Foundation

2014 ◽  
Author(s):  
Byung Chang Kwag ◽  
Moncef Krarti
Keyword(s):  
Numerical Model ◽  
Factor Model ◽  
Three Dimensional ◽  
Thermal Response ◽  
Building Energy ◽  
Sensitivity Analyses ◽  
Response Factor ◽  
Response Factors ◽  
Building Foundation ◽  
Whole Building Energy Simulation

A transient three-dimensional finite difference numerical model was developed for the analysis of thermo-active foundations. The numerical model predictions were validated against experimental data obtained from laboratory testing. Using the validated 3D numerical model, a series of parameter sensitivity analyses was performed. It was found that the foundation depth, the shank space, the fluid flow rate, and thermal conductivity of ground and concrete affected the thermal performance of a thermo-active foundation system. Moreover, utilizing the numerical model, thermal response factors for thermo-active foundations were developed and implemented into a whole building energy simulation program. The thermal-response factor method was then used to estimate the effects of thermo-active foundations to reduce the energy consumption needed to condition commercial buildings.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

Spreadsheet Tool for Quick-Turn 3D Numerical Modeling of Package Thermal Performance With Non-Uniform Die Heating

2001 ◽  
Author(s):  
Abhay A. Watwe ◽  
Ravi S. Prasher
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Finite Volume ◽  
Thermal Performance ◽  
Three Dimensional ◽  
3D Numerical Modeling ◽  
Conventional Analysis ◽  
Time Required ◽  
The Impact ◽  
Fourier Equation

Abstract Traditional methods of estimating package thermal performance employ numerical modeling using commercially available finite-volume or finite-element tools. Use of these tools requires training and experience in thermal modeling. This methodology restricts the ability of die designers to quickly evaluate the thermal impact of their die architecture due to the added throughput time required to enlist the services of a thermal analyst. This paper describes the development of an easy to use spreadsheet tool, which performs quick-turn numerical evaluations of the impact of non-uniform die heating. The tool employs well-established finite-volume numerical techniques to solve the steady-state, three-dimensional Fourier equation of conduction in the package geometry. Minimal input data is required and the inputs are customized using visual basic pull-down menus to assist die designers who may not be thermal experts. Data showing comparison of the estimates from the spreadsheet tool with that obtained from a conventional analysis using the commercially available finite element code ANSYS™ is also presented.

scholarly journals BESTest for Integrated Outdoor-Indoor Energy Balance Modelling

2021 ◽  
Author(s):  
Mohammed Bakkali ◽  
Yasunobu Ashie
Keyword(s):  
Energy Balance ◽  
Three Dimensional ◽  
Building Blocks ◽  
Building Energy ◽  
Energy Simulation ◽  
Balance Model ◽  
Fully Integrated ◽  
Heat Islands ◽  
Urban Heat ◽  
The Impact

In our growing cities, climate change and energy related uncertainties are of great concern. The impact of the Urban Heat Island on comfort, health and the way we use energy still requires further clarification. The outdoor-indoor energy balance model (3D-City Irradiance) presented in this article was developed so as to address these issues. The effects of view factors between urban surfaces on three-dimensional radiation and the effects of fully integrated outdoor-indoor energy balance schemes on heat islands and building indoor thermal loads could be included within different building blocks at a resolution of several metres. The model operated under the ‘stand alone’ mode. It was tested using the Building Energy Simulation Test (BESTest) which demonstrated good levels of agreement for diurnal and seasonal simulations.

scholarly journals An Optimization-Based Supervisory Control and Coordination Approach for Solar-Load Balancing in Building Energy Management

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1215
Author(s):  
James Allen ◽  
Ari Halberstadt ◽  
John Powers ◽  
Nael H. El-Farra
Keyword(s):  
Solar Energy ◽  
Energy Use ◽  
Weather Forecasting ◽  
Energy Generation ◽  
Building Energy ◽  
Objective Functions ◽  
Forecasting Accuracy ◽  
Electricity Cost ◽  
The Impact ◽  
Building Loads

This work considers the problem of reducing the cost of electricity to a grid-connected commercial building that integrates on-site solar energy generation, while at the same time reducing the impact of the building loads on the grid. This is achieved through local management of the building’s energy generation-load balance in an effort to increase the feasibility of wide-scale deployment and integration of solar power generation into commercial buildings. To realize this goal, a simulated building model that accounts for on-site solar energy generation, battery storage, electrical vehicle (EV) charging, controllable lighting, and air conditioning is considered, and a supervisory model predictive control (MPC) system is developed to coordinate the building’s generation, loads and storage systems. The main aim of this optimization-based approach is to find a reasonable solution that minimizes the economic cost to the electricity user, while at the same time reducing the impact of the building loads on the grid. To assess this goal, three objective functions are selected, including the peak building load, the net building energy use, and a weighted sum of both the peak load and net energy use. Based on these objective functions, three MPC systems are implemented on the simulated building under scenarios with varying degrees of weather forecasting accuracy. The peak demand, energy cost, and electricity cost are compared for various forecast scenarios for each MPC system formulation, and evaluated in relation to a rules-based control scheme. The MPC systems tested the rules-based scheme based on simulations of a month-long electricity consumption. The performance differences between the individual MPC system formulations are discussed in the context of weather forecasting accuracy, operational costs, and how these impact the potential of on-site solar generation and potential wide-spread solar penetration.

Thermomechanical Finite Element Analysis of Impact-Induced Magnetic Erasures in Magnetic Storage Thin Film Media

2007 ◽  
Author(s):  
Ning Yu ◽  
Andreas A. Polycarpou ◽  
Jorge V. Hanchi
Keyword(s):  
Finite Element ◽  
Hard Disk Drives ◽  
Three Dimensional ◽  
Thermal Response ◽  
Rotating Disk ◽  
Oblique Impact ◽  
Magnetic Storage ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Impact

Oblique impact of a slider with a rotating disk in hard disk drives was analyzed using the finite element method. A three dimensional, thermomechanical, impact model was developed to study the mechanical and thermal response during the impact of a spherical slider corner with the disk. The model was validated by comparing finite element results with analytical solutions for homogeneous glass disk under simple conditions. Impact penetration, stress and incurred flash temperature were obtained for various normal impact velocities.

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