scholarly journals Modification of building energy simulation tool TRNSYS for modelling nonlinear heat and moisture transfer phenomena by TRNSYS/MATLAB integration

2020 ◽  
Vol 172 ◽  
pp. 25009
Author(s):  
Ajaya Ketan Nayak ◽  
Aya Hagishima
Keyword(s):  
Numerical Simulation ◽  
Moisture Transfer ◽  
Ambient Air ◽  
Building Energy ◽  
Energy Simulation ◽  
Modular Structure ◽  
Integration Scheme ◽  
Building Energy Simulation ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Software for numerical simulation of various types of energy used in buildings, i.e. building energy simulation (BES), have become an essential tool for recent research pertaining to building physics. TRNSYS is a well-known BES used in both academia and the construction industry for a wide range of simulations, such as the design and performance evaluation of buildings and related facilities for heating, cooling, and ventilation. TRNSYS has a modular structure comprising various components, and each component is interconnected and compiled through a common interface using a FORTRAN compiler. Its modular structure enables interactions with various external numerical simulation tools, such as MATLAB, Python, and ESP-r. For ordinary simulations of building energy load using TRNSYS, the generic module Type 56 is usually recommended, which provides detailed physics modelling of building thermal behaviours based on unsteady energy conservation equations and Fourier’s law for each building material. However, Type 56 explicitly depends on the transfer function method to discretise the original differential equations; therefore, it cannot model nonlinear phenomena, such as latent heat and moisture transfer between a building surface and ambient air. In other words, the current TRNSYS cannot be used to estimate the effectiveness of evaporation during cooling, which is a typical passive design method. Hence, the authors developed a MATLAB/TRNSYS integration scheme, in which TRNSYS was modified to model simultaneous heat and moisture transfer from the wet roof surface of a building. This scheme enabled TRNSYS to calculate the rate of evaporative heat and moisture transfer dynamically from the roof surface, assuming a control volume approximation of the roof surface. Finally, the effect of evaporative cooling on the thermal performance of an Indian building was estimated using the modified model.

scholarly journals Application Method of a Simplified Heat and Moisture Transfer Model of Building Construction in Residential Buildings

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4180
Author(s):  
Joowook Kim ◽  
Michael Brandemuehl
Keyword(s):  
Latent Heat ◽  
Moisture Transfer ◽  
Residential Buildings ◽  
Building Energy ◽  
The United States ◽  
Building Envelope ◽  
Outdoor Environment ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Several building energy simulation programs have been developed to evaluate the indoor conditions and energy performance of buildings. As a fundamental component of heating, ventilating, and air conditioning loads, each building energy modeling tool calculates the heat and moisture exchange among the outdoor environment, building envelope, and indoor environments. This paper presents a simplified heat and moisture transfer model of the building envelope, and case studies for building performance obtained by different heat and moisture transfer models are conducted to investigate the contribution of the proposed steady-state moisture flux (SSMF) method. For the analysis, three representative humid locations in the United States are considered: Miami, Atlanta, and Chicago. The results show that the SSMF model effectively complements the latent heat transfer calculation in conduction transfer function (CTF) and effective moisture penetration depth (EMPD) models during the cooling season. In addition, it is found that the ceiling part of a building largely constitutes the latent heat generated by the SSMF model.

Numerical Simulation of Heat, Air, and Moisture Transfer Through a Wall of Porous Media

2020 ◽  
Author(s):  
Kiflom B. Tesfamariam ◽  
Cheng-Xian (Charlie) Lin ◽  
Fang Liu
Keyword(s):  
Numerical Simulation ◽  
Moisture Transport ◽  
Moisture Transfer ◽  
Simulation Software ◽  
Transport Processes ◽  
Two Dimensional ◽  
Heat And Moisture Transfer ◽  
Porous Walls ◽  
Heat And Moisture ◽  
Benchmark Solutions

Abstract This paper presents the results of two-dimensional (2D) numerical simulation of heat, air, and moisture transfer through porous walls, which have important application background in the built environment and other engineering fields. The air flows, heat and moisture transfer in the walls are studied using a transient heat, air, and moisture (HAM) model. This model treats the non-isothermal airflow through two-dimensional porous geometries in a time-dependent format. The model includes the Brinkman equation describes the flow of air and other mathematical equations that calculate the heat and moisture transfer through the porous region. The equations are solved by a finite element method (FEM) using physics-based modeling, which is implemented in the commercial simulation software, COMSOL Multiphysics. The model prediction is first validated by using published benchmark solutions. Eventually, the numerical results are presented to illustrate the complex effects of material porosity and permeability on the heat and moisture transport, and moisture content variation in space and time through the walls, at different humidity and temperature conditions. Within the investigated parameter ranges, it is demonstrated that the relative humidity and temperature difference are the driving forces for the transient heat, air, and moisture transport processes through the porous area in the porous walls.

Numerical Simulation of Hygro-Thermal Deformation of Concrete Based on Heat and Moisture Transfer

2010 ◽  
Vol 129-131 ◽  
pp. 179-184
Author(s):  
De Peng Chen ◽  
Chun Lin Liu ◽  
Chun Xiang Qian
Keyword(s):  
Numerical Simulation ◽  
Life Prediction ◽  
Thermal Deformation ◽  
Analytic Solution ◽  
Moisture Transfer ◽  
Heat And Moisture Transfer ◽  
Element Analysis ◽  
Moisture Condition ◽  
Heat And Moisture ◽  
Visual Basic 6.0

Concrete deformation due to temperature and moisture condition will always develop simultaneously and interactively. The numerical simulation of hygro-thermal deformation of concrete is necessary to be investigated for better serviceability, durability estimation and life prediction. In this paper, a numerical simulation procedure was proposed for hygro-thermal deformation of concrete based on the principle of heat and moisture transfer in porous medium. The procedure comprised an analytic solution of heat and moisture transfer, a calculation of moisture induced stress and a finite element analysis (FEM) of hygro-thermal deformation. The methodology of a software named Coupling Temperature and Moisture Simulation System for concrete (CTMSoft) was represented and developed by a mix programming. The graphical user interface (GUI) of the software was programmed by Visual Basic 6.0 and its real numerical calculation process was conducted by calling Matlab and ANSYS. The efficiency of the CTMSoft was validated by a case analysis of the data of Hundt’s test.

Numerical Simulation of Heat and Moisture Transfer in System of Human-Clothing with Phase Change Materials-Environment

2011 ◽  
Vol 88-89 ◽  
pp. 470-474
Author(s):  
Feng Zhi Li ◽  
Peng Fei Wang ◽  
Yi Li
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Phase Change ◽  
Skin Temperature ◽  
Phase Change Materials ◽  
Moisture Transfer ◽  
Heat And Moisture Transfer ◽  
Model Predictions ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

A model of heat and moisture transfer in human-clothing with PCM-environment system is developed. In the model, the improved 25-node model is used for simulating human thermo- regulation, and the coupled heat and moisture model is applied to the PCM’s clothing. The model predictions and experimental data are compared. Also, the influences of the PCM on human skin temperature and sweat accumulation are predicted. The results are helpful to design of thermal functional clothing.

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