A Model for Assessment of Heat and Moisture Transfer Hollow a Hemp Concerte Wall Using Finite Element Method

2022 ◽  
Author(s):  
Salah Ouldboukhitine ◽  
Sofiane Amziane ◽  
Maroua Benkhaled
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Consumption ◽  
Moisture Transfer ◽  
Energy Performance ◽  
Vapor Permeability ◽  
Heat And Moisture Transfer ◽  
Concrete Wall ◽  
Heat And Moisture ◽  
Element Method

The energy performance of buildings represents a major challenge in terms of sustainable development. The buildings and buildings construction sectors combined are responsible for over one-third of global final energy consumption and nearly 40% of total direct and indirect CO2 emissions. In order to reduce the energy consumption of buildings and their harmful impact on the environment, special attention has been paid in recent years to the use of bio-based materials. In the present paper, a model of heat and moisture transfer hollow hemp concrete wall is proposed using finite element method. The energy and mass balances are expressed using measurable transfer drivers as temperature water content and vapor pressure and coefficients related explicitly to the macroscopic properties of material as thermal conductivity, specific heat, and water vapor permeability. The proposed model is implemented in MATLAB code and validated through experimental measurements.

scholarly journals A 1D Model for Predicting Heat and Moisture Transfer through a Hemp-Concrete Wall Using the Finite-Element Method

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6903
Author(s):  
Maroua Benkhaled ◽  
Salah-Eddine Ouldboukhitine ◽  
Amer Bakkour ◽  
Sofiane Amziane
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Transfer ◽  
Construction Material ◽  
Climatic Conditions ◽  
Vapor Permeability ◽  
Transfer Model ◽  
The Finite Element Method ◽  
Concrete Wall ◽  
Element Method

Plant-based concrete is a construction material which, in addition to having a very low environmental impact, exhibits excellent hygrothermal comfort properties. It is a material which is, as yet, relatively unknown to engineers in the field. Therefore, an important step is to implement reliable mass-transfer simulation methods. This will make the material easy to model, and facilitate project design to deliver suitable climatic conditions. In recent decades, numerous studies have been carried out to develop models of the coupled transfers of heat, air and moisture in porous building envelopes. Most previous models are based on Luikov’s theory, considering mass accumulation, air and total pressure gradient. This theory considers the porous medium to be homogeneous, and therefore allows for hygrothermal transfer equations on the basis of the fundamental principles of thermodynamics. This study presents a methodology for solving the classical 1D (one-dimensional) HAM (heat, air, and moisture) hygrothermal transfer model with an implementation in MATLAB. The resolution uses a discretization of the problem according to the finite-element method. The detailed solution has been tested on a plant-based concrete. The energy and mass balances are expressed using measurable transfer quantities (temperature, water content, vapor pressure, etc.) and coefficients expressly related to the macroscopic properties of the plant-based concrete (thermal conductivity, specific heat, water vapor permeability, etc.), determined experimentally. To ensure this approach is effective, the methodology is validated on a test case. The results show that the methodology is robust in handling a rationalization of the model whose parameters are not ranked and not studied by their degree of importance.

Development of a numerical approach to assess the effect of coupled heat and moisture transfer on energy consumption of residential buildings in Moroccan context

2021 ◽  
pp. 174425912110560
Author(s):  
Yassine Chbani Idrissi ◽  
Rafik Belarbi ◽  
Mohammed Yacine Ferroukhi ◽  
M’barek Feddaoui ◽  
Driss Agliz
Keyword(s):  
Energy Consumption ◽  
Building Materials ◽  
Moisture Transfer ◽  
Residential Buildings ◽  
Building Design ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Heat And Moisture Transfer ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

Hygrothermal properties of building materials, climatic conditions and energy performance are interrelated and have to be considered simultaneously as part of an optimised building design. In this paper, a new approach to evaluate the energy consumption of residential buildings in Morocco is presented. This approach is based on the effect of coupled heat and moisture transfer in typical residential buildings and on their responses to the varied climatic conditions encountered in the country. This approach allows us to evaluate with better accuracy the response of building energy performance and the indoor comfort of building occupants. Annual energy consumption, cooling and heating energy requirements were estimated considering the six climatic zones of Morocco. Based on the results, terms related to coupled heat and moisture transfer can effectively correct the existing energy consumption calculations of the six zones of Morocco, which currently do not consider energy consumption due to coupled heat and moisture transfer.

scholarly journals Solution of Nonlinear Coupled Heat and Moisture Transport Using Finite Element Method

10.14311/622 ◽  
2004 ◽  
Vol 44 (5-6) ◽  
Author(s):  
T. Krejčí
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Transfer ◽  
Coupled Problems ◽  
Algebraic Equations ◽  
Capillary Pressures ◽  
Coupled Heat And Moisture ◽  
Attention Systems ◽  
Heat And Moisture ◽  
Element Method

This paper deals with a numerical solution of coupled of heat and moisture transfer using the finite element method. The mathematical model consists of balance equations of mass, energy and linear momentum and of the appropriate constitutive equations. The chosen macroscopic field variables are temperature, capillary pressures, gas pressure and displacement. In contrast with pure mechanical problems, there are several difficulties which require special attention. Systems of algebraic equations arising from coupled problems are generally nonlinear, and the matrices of such systems are nonsymmetric and indefinite. The first experiences of solving complicated coupled problems are mentioned in this paper. 

Modelling of Heat and Moisture Transfer Phenomena During Dry Biscuit Baking by Using Finite Element Method

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Enrico Ferrari ◽  
Simone V. Marai ◽  
Riccardo Guidetti ◽  
Laura Piazza
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Transfer ◽  
Continuous Functions ◽  
Transfer Model ◽  
The Finite Element Method ◽  
Baking Process ◽  
Heat And Moisture ◽  
The Mathematical Model ◽  
Element Method

Abstract This paper validates a simultaneous heat and mass transfer model proposed to describe the discontinuous biscuit baking process. The mathematical model includes the moving evaporation front and the development of the crust observed during the baking process. The problem is solved over a two-dimensional geometry using the finite element method. Thermo-physical properties were computed by means of continuous functions. Variations in temperature and water content during baking were predicted with high to discrete accuracy using this model.

Effects of Various Edge-Curve Types and Rotational Speeds of Disc Blades on Breaking Force and Energy Consumption in the Maize Stalk Chopping Process

2021 ◽  
Vol 37 (5) ◽  
pp. 951-965
Author(s):  
Peng Liu ◽  
Jin He ◽  
Hongwen Li ◽  
Qingjie Wang ◽  
Caiyun Lu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Consumption ◽  
Fem Simulation ◽  
Influential Factor ◽  
List Type ◽  
Breaking Force ◽  
Field Validation ◽  
Validation Experiment ◽  
Element Method

HighlightsThe peak breaking force and energy consumption change in maize stalk were predicted by the FEM.A high SADBT reduced the PBFR and PBFS and increased the ECSC.The TRYDB had the most critical effect on the peak breaking force and energy consumption.Abstract. The mechanized retention of stalks is the primary method to avoid open burning. However, the variation in the breaking force and energy consumption in the chopping process of mechanized retention must be clarified. Therefore, based on the finite element method (FEM) and field validation experiments, the effects of various edge-curve types and rotational speeds of disc blades for maize stalk retention on the breaking force and energy consumption were examined. The test indices were the peak breaking force of the rind (PBFR) and stalk (PBFS), energy consumption of stalk chopping (ECSC), and energy transmission efficiency (ETE). The test factors were the spiral disc blade type (Archimedean, logarithmic, and sinusoidal-exponential spiral), slide-cutting angles of the disc blade tip (SADBT, 30°, 40°, 50°, and 60°), rotational speed of the Y-type blade (RSYB, 1400, 1600, 1800, 2000, 2200, and 2400 rpm), and transmission ratio between Y-type and disc blades (TRYDB, 0.25, 0.50, 0.75, and 1.0). The chopping process was divided into the cutting processes of the initial rind, rind and pith, final rind, and stalk end. The results showed that the SADBT, TRYDB, and RSYB had significant effects on the PBFR, PBFS, ECSC, and ETE. The most influential factor on all test indices was the TRYDB. The RSYB positively affected the PBFR, PBFS, and ECSC. The growth rates of the PBFR, PBFS, and ECSC increased with the TRYDB. The maximum PBFR, PBFS, and ETE values were obtained under an SADBT of 60°, and the maximum ECSC value was obtained under an SADBT of 40°. The difference in energy consumption between the field validation experiment and simulation was less than 10%, which proved the correct results of the FEM simulation. Keywords: Energy consumption, Finite element method, Maize stalk, Peak breaking force, Slide cutting.

scholarly journals Simulation Research on the Effect of Coupled Heat and Moisture Transfer on the Energy Consumption and Indoor Environment of Public Buildings

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 141 ◽  
Author(s):  
Shui Yu ◽  
Yumeng Cui ◽  
Yifei Shao ◽  
Fuhong Han
Keyword(s):  
Energy Consumption ◽  
Indoor Environment ◽  
Moisture Transfer ◽  
Building Envelope ◽  
Thermal Calculation ◽  
Heat And Moisture Transfer ◽  
Building Envelopes ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture ◽  
Humidity Environment

A building envelope is a multi-layer porous structure. It transfers heat and moisture to balance the indoor and outdoor temperature difference and water vapor partial pressure difference. This is a typical coupled heat and moisture migration process. When the space is filled with moist air, water or ice, it will directly affect the thermal properties of the material. With respect to moisture coming through the wall into the indoor building, it will also affect the indoor environment and the energy consumption due to the formation of latent heat. However, the moisture transfer process in the building envelopes is not taken into account in the current conventional thermal calculation and energy consumption analysis. This paper analyzes the indoor thermal and humidity environment and building energy consumption of typical cities in Harbin, Shenyang, Beijing, Shanghai, and Guangzhou. The results show that it is obvious that the coupled heat and moisture transfer in the building envelopes has an impact on the annual cooling and heating energy consumption, the total energy consumption, and the indoor thermal and humidity environment. The geographical location of buildings ranging from north to south influences the effect of coupled heat and moisture transfer on the annual energy consumption of the building, moving from positive to negative. It is suggested that the additional coefficient of the coupled thermal and moisture method can effectively correct the existing energy consumption calculation results, which do not take the consumption from the coupled heat and moisture in the building envelopes into account.

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