The Experts below are selected from a list of 23430 Experts worldwide ranked by ideXlab platform

A Pasupathy - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation and numerical simulation analysis on the thermal performance of a building roof incorporating phase change material pcm for thermal management
    Applied Thermal Engineering, 2008
    Co-Authors: A Pasupathy, R Velraj, L Athanasius, R V Seeniraj
    Abstract:

    Thermal storage plays a major role in a wide variety of industrial, commercial and residential application when there is a mismatch between the supply and demand of energy. Latent heat storage in a phase change material (PCM) is very attractive, because of its high-energy storage density and its isothermal behavior during the phase change process. Several promising developments are taking place in the field of thermal storage using phase change materials (PCM) in buildings. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Increasing the thermal storage capacity of a building can enhance human comfort by decreasing the frequency of Internal Air Temperature swings, so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper attempts to study the thermal performance of an inorganic eutectic PCM based thermal storage system for thermal management in a residential building. The system has been analyzed by theoretical and experimental investigation. Experiments are also conducted by circulating water through the tubes kept inside the PCM panel to test its suitability for the summer months. In order to achieve the optimum design for the selected location, several simulation runs are made for the average ambient conditions for all the months in a year and for the various other parameters of interest.

  • effect of double layer phase change material in building roof for year round thermal management
    Energy and Buildings, 2008
    Co-Authors: A Pasupathy, R Velraj
    Abstract:

    Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Latent heat storage in a phase change material (PCM) is very attractive because of its high-energy storage density and its isothermal behavior during the phase change process. Thermal storage plays a major role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage in building products. Increasing the thermal storage capacity of a building can enhance human comfort by decreasing the frequency of Internal Air Temperature swings so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. However, it is impossible to select a phase change material to suit all the weather condition in a given location. The PCM that reduces the Internal Air Temperature swing during the winter season is not suitable for the summer season as the PCM remains in the liquid state at all the times during these months and hence the system cannot exploit the latent heat effect. This paper attempts to study the thermal performance of an inorganic eutectic PCM based thermal storage system for thermal management in a residential building. The system has been analyzed by theoretical and experimental investigation. A double layer PCM concept is studied in detail to achieve year round thermal management in a passive manner.

  • phase change material based building architecture for thermal management in residential and commercial establishments
    Renewable & Sustainable Energy Reviews, 2008
    Co-Authors: A Pasupathy, R Velraj, R V Seeniraj
    Abstract:

    Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Thermal storage plays an important role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage (LHS) in building products. LHS in a phase change material (PCM) is very attractive because of its high storage density with small Temperature swing. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Thermal energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating or embedding suitable PCMs within these surfaces. They can either capture solar energy directly or thermal energy through natural convection. Increasing the thermal storage capacity of a building can increase human comfort by decreasing the frequency of Internal Air Temperature swings so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper aims to gather the information from the earlier works on the developments of PCM's incorporation in building, the problems associated with the selection of PCM and the various methods used to contain them for space heating and cooling applications.

R V Seeniraj - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation and numerical simulation analysis on the thermal performance of a building roof incorporating phase change material pcm for thermal management
    Applied Thermal Engineering, 2008
    Co-Authors: A Pasupathy, R Velraj, L Athanasius, R V Seeniraj
    Abstract:

    Thermal storage plays a major role in a wide variety of industrial, commercial and residential application when there is a mismatch between the supply and demand of energy. Latent heat storage in a phase change material (PCM) is very attractive, because of its high-energy storage density and its isothermal behavior during the phase change process. Several promising developments are taking place in the field of thermal storage using phase change materials (PCM) in buildings. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Increasing the thermal storage capacity of a building can enhance human comfort by decreasing the frequency of Internal Air Temperature swings, so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper attempts to study the thermal performance of an inorganic eutectic PCM based thermal storage system for thermal management in a residential building. The system has been analyzed by theoretical and experimental investigation. Experiments are also conducted by circulating water through the tubes kept inside the PCM panel to test its suitability for the summer months. In order to achieve the optimum design for the selected location, several simulation runs are made for the average ambient conditions for all the months in a year and for the various other parameters of interest.

  • phase change material based building architecture for thermal management in residential and commercial establishments
    Renewable & Sustainable Energy Reviews, 2008
    Co-Authors: A Pasupathy, R Velraj, R V Seeniraj
    Abstract:

    Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Thermal storage plays an important role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage (LHS) in building products. LHS in a phase change material (PCM) is very attractive because of its high storage density with small Temperature swing. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Thermal energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating or embedding suitable PCMs within these surfaces. They can either capture solar energy directly or thermal energy through natural convection. Increasing the thermal storage capacity of a building can increase human comfort by decreasing the frequency of Internal Air Temperature swings so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper aims to gather the information from the earlier works on the developments of PCM's incorporation in building, the problems associated with the selection of PCM and the various methods used to contain them for space heating and cooling applications.

Abdelkader Mami - One of the best experts on this subject based on the ideXlab platform.

  • Experimental validation of the dynamic thermal behavior of two types of agricultural greenhouses in the Mediterranean context
    Renewable Energy, 2020
    Co-Authors: Rim Ben Ali, Salwa Bouadila, Abdelkader Mami
    Abstract:

    Abstract Agricultural greenhouses are used to maintain a favorable microclimate for production and plant growth and also to protect the canopy against diseases. The objective of this work is to develop a dynamic model describing the thermal behaviors indoor the greenhouse in order to predict the evolution of the Internal Air Temperature under two kinds of greenhouses. The first one is a transparent greenhouse and the second one is an insulated greenhouse, which are installed in the Research and Technologies Centre of Energy in Borj Cedria (CRTEn) in Tunisia (Latitude 36°43′ and Longitude 10°25′). For this purpose, a thermodynamic modeling was proposed and simulated under MATLAB/Simulink environment to be experimentally validated into the two agricultural greenhouses during 9 days in March. The simulation results were compared to the experimental data and the fAir agreement between the predicted and measured values showed the efficiency of the proposed dynamic model to predict the Air Temperature indoor the greenhouses with a few percentages error.

  • Development of a Fuzzy Logic Controller applied to an agricultural greenhouse experimentally validated
    Applied Thermal Engineering, 2018
    Co-Authors: Rim Ben Ali, Salwa Bouadila, Abdelkader Mami
    Abstract:

    Abstract The agricultural greenhouse presents a complicated procedure since the strong perturbations and the important number of its input parameters, which have a great potential and capacity to influence the climate inside it. For this reason, a Fuzzy Logic Controller (FLC) is developed in order to promote a suitable microclimate by activating the appropriate actuators installed inside the greenhouse with the appropriate rate. The dynamic modeling of the studied greenhouse is presented and simulated under MATLAB/Simulink environment to be experimentally validated within the Research and Technology Center of Energy (CRTEn) in Tunisia. The simulation results illustrate the effectiveness of the proposed dynamic model to investigate the Internal Air Temperature and relative humidity with a low percentage of error. In addition, the developed controller FLC presents an effective solution to get an optimized microclimate indoor the agricultural greenhouse.

  • Application of a controlled outside cold Airflow by a PID controller to improve the performance of a household refrigerator
    International Journal of Electrical and Computer Engineering (IJECE), 2016
    Co-Authors: Emna Aridhi, Mehdi Abbes, Abdelkader Mami
    Abstract:

    The present paper aims to prove the efficiency of using the cold to improve the performance of a household refrigerator. It is produced naturally in countries that are characterized by a severe wintry climate. The cold Airflow is spread out inside a cavity covering the side wall of the appliance, which is connected to the inlet and outlet ducts. For that purpose, a Simulink model is proposed to model this installation. The Internal Air Temperature is computed according to the evaporator Temperature and the outside cold Airflow that is also computed according to the outside Temperature and controlled by a PID controller. The simulation results show that when the Internal Air Temperature is higher than the desired one and the outside Temperature is low enough, the controlled cold Airflow used as a second cooling source allowed to speed-up the cooling inside the refrigerator compartment of about 36.21% and to reach an energy saving of about 36.23% compared with the classical thermostatic control.

  • PID and fuzzy logic optimized controller for Temperature control in a cavity of refrigeration
    IREC2015 The Sixth International Renewable Energy Congress, 2015
    Co-Authors: Jouda Arfaoui, Elyes Feki, Abdelkader Mami
    Abstract:

    Genetic algorithm has been widely used in the various optimal problems. Its application in the fuzzy control is still limited by factors such as local optimal and premature convergence. Therefore, this paper proposes an alternative method for designing fuzzy logic controller for Temperature control inside the cavity of refrigeration. The control strategy was applied to a third-order discrete state space system, which computes the Internal Air Temperature according to the Temperature at the level of the evaporator exchanger. The system was obtained by linearization of a pseudo bond graph model of thermal transfers inside the refrigeration cavity. A performance comparison was carried out with PID controller to show the effectiveness of the proposed method.

  • Temperature control in a cavity of refrigeration using PI controller and predictive control
    2014 15th International Conference on Sciences and Techniques of Automatic Control and Computer Engineering (STA), 2014
    Co-Authors: Emna Aridhi, Mehdi Abbes, Abdelkader Mami
    Abstract:

    A PI controller and a generalized predictive control strategy of the Temperature inside a cavity of refrigeration are proposed, using Matlab/Simulink environment. The control strategies were applied to a third-order discrete state space system, which computes the Internal Air Temperature according to the Temperature at the level of the evaporator exchanger, under the influence of the ambient Temperature. The system was obtained by linearization of a pseudo bond graph model of thermal transfers inside the refrigeration cavity. The simulation results were compared to those of the pseudo bond graph model for a classical thermostatic control. The used control strategies allowed an average energy saving of about 70% compared with the conventional on/off controller.The predictive control was more efficient than the PI controller of 23.33 %.

R Velraj - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation and numerical simulation analysis on the thermal performance of a building roof incorporating phase change material pcm for thermal management
    Applied Thermal Engineering, 2008
    Co-Authors: A Pasupathy, R Velraj, L Athanasius, R V Seeniraj
    Abstract:

    Thermal storage plays a major role in a wide variety of industrial, commercial and residential application when there is a mismatch between the supply and demand of energy. Latent heat storage in a phase change material (PCM) is very attractive, because of its high-energy storage density and its isothermal behavior during the phase change process. Several promising developments are taking place in the field of thermal storage using phase change materials (PCM) in buildings. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Increasing the thermal storage capacity of a building can enhance human comfort by decreasing the frequency of Internal Air Temperature swings, so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper attempts to study the thermal performance of an inorganic eutectic PCM based thermal storage system for thermal management in a residential building. The system has been analyzed by theoretical and experimental investigation. Experiments are also conducted by circulating water through the tubes kept inside the PCM panel to test its suitability for the summer months. In order to achieve the optimum design for the selected location, several simulation runs are made for the average ambient conditions for all the months in a year and for the various other parameters of interest.

  • effect of double layer phase change material in building roof for year round thermal management
    Energy and Buildings, 2008
    Co-Authors: A Pasupathy, R Velraj
    Abstract:

    Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Latent heat storage in a phase change material (PCM) is very attractive because of its high-energy storage density and its isothermal behavior during the phase change process. Thermal storage plays a major role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage in building products. Increasing the thermal storage capacity of a building can enhance human comfort by decreasing the frequency of Internal Air Temperature swings so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. However, it is impossible to select a phase change material to suit all the weather condition in a given location. The PCM that reduces the Internal Air Temperature swing during the winter season is not suitable for the summer season as the PCM remains in the liquid state at all the times during these months and hence the system cannot exploit the latent heat effect. This paper attempts to study the thermal performance of an inorganic eutectic PCM based thermal storage system for thermal management in a residential building. The system has been analyzed by theoretical and experimental investigation. A double layer PCM concept is studied in detail to achieve year round thermal management in a passive manner.

  • phase change material based building architecture for thermal management in residential and commercial establishments
    Renewable & Sustainable Energy Reviews, 2008
    Co-Authors: A Pasupathy, R Velraj, R V Seeniraj
    Abstract:

    Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Thermal storage plays an important role in building energy conservation, which is greatly assisted by the incorporation of latent heat storage (LHS) in building products. LHS in a phase change material (PCM) is very attractive because of its high storage density with small Temperature swing. It has been demonstrated that for the development of a latent heat storage system (LHTS) in a building fabric, the choice of the PCM plays an important role in addition to heat transfer mechanism in the PCM. Thermal energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating or embedding suitable PCMs within these surfaces. They can either capture solar energy directly or thermal energy through natural convection. Increasing the thermal storage capacity of a building can increase human comfort by decreasing the frequency of Internal Air Temperature swings so that the indoor Air Temperature is closer to the desired Temperature for a longer period of time. This paper aims to gather the information from the earlier works on the developments of PCM's incorporation in building, the problems associated with the selection of PCM and the various methods used to contain them for space heating and cooling applications.

Behdad Moghtaderi - One of the best experts on this subject based on the ideXlab platform.

  • The Significance of Sky Temperature in the Assessment of the Thermal Performance of Buildings
    Applied Sciences, 2020
    Co-Authors: Aiman Albatayneh, Dariusz Alterman, Adrian Page, Behdad Moghtaderi
    Abstract:

    Energy-efficient building design needs an accurate way to estimate Temperature inside the building which facilitates the calculation of heating and cooling energy requirements in order to achieve appropriate thermal comfort for occupants. Sky Temperature is an important factor for any building assessment tool which needs to be precisely determined for accurate estimation of the energy requirement. Many building simulation tools have been used to calculate building thermal performance such as Autodesk Computational Fluid Dynamics (CFD) software, which can be used to calculate building Internal Air Temperature but requires sky Temperature as a key input factor for the simulation. Real data obtained from real-sized house modules located at University of Newcastle, Australia (southern hemisphere), were used to find the impact of different sky Temperatures on the building’s thermal performance using CFD simulation. Various sky Temperatures were considered to determine the accurate response which aligns with a real trend of buildings’ Internal Air Temperature. It was found that the Internal Air Temperature in a building keeps either rising or decreasing if higher or lower sky Temperature is chosen. This significantly decreases the accuracy of the simulation. It was found that using the right sky Temperature values for each module, Cavity Brick Module (CB) Insulated Cavity Brick Module (InsCB), Insulated Brick Veneer Module (InsBV) and Insulated Reverse Brick Veneer Module (InsRBV), will result in 6.5%, 7.1%, 6.2% and 6.4% error correspondingly compared with the real data. These errors mainly refer to the simulation error. On the other hand using higher sky Temperatures by +10 °C will significantly increase the simulation error to 16.5%, 17.5%, 17.1% and 16.8% and lower sky Temperature by +10 °C will also increase the error to 19.3%, 22.6%, 21.9% and 19.1% for CB, InsCB, InsBV and InsRBV modules, respectively.

  • Development of a new metric to characterise the buildings thermal performance in a temperate climate
    Energy for Sustainable Development, 2019
    Co-Authors: Aiman Albatayneh, Dariusz Alterman, Adrian Page, Behdad Moghtaderi
    Abstract:

    Abstract The paper describes the development of a new metric to evaluate the thermal performance of residential houses for temperate climates, named the Adaptive Thermal Metric (ATM). The proposed ATM helps the evaluation of the thermal performance of an entire house by finding the Internal Air Temperature of the building using Computational Fluid Dynamics (CFD) simulation then computes the fraction of time over which the Internal Air Temperature of the house stayed within the 90% or 80% adaptive thermal comfort limits (designated ATM90 and ATM80 respectively). The adaptive thermal comfort approach allows inhabitants to choose an adequate range of Internal Air Temperatures by implementing other adaptive practices such as changing clothes, opening windows, or using low energy solutions (e.g. fans) to adjust their thermal comfort level. The new metric uses Temperature to assess a building's thermal performance. This differs from other commonly conventional approaches, which are established based on the amount of energy usage required to sustain an inhabitant's thermal comfort. To verify the modelling technique, the CFD simulated Internal Air Temperatures were compared with the actual Temperatures recorded for four full-scale housing test modules, each incorporating a different walling system. This comparison yielded an average accuracy of 93% at any given time for all simulated modules over the 12-month simulation period. Using the above CFD approach, the ATMs were calculated for each building test module over the studied period. The final results showed that the best thermal performance module was the Insulated Cavity Brick module (InsCB), followed by the Insulated Reverse Brick Veneer (InsRBV), Insulated Brick Veneer (InsBV) and Cavity Brick (CB) modules. These findings were accordant with both the house evaluation software used in Australia (i.e. AccuRate) and the earlier results on the walling systems research done by the University of Newcastle in Australia, which were used to assess the accuracy of the ATM. The results indicated that the ATM has the potential to be used as an alternative building evaluation technique to assess the overall building thermal performance in temperate climates.

  • An Alternative Approach to the Simulation of Wind Effects on the Thermal Performance of Buildings
    International Journal of Computational Physics Series, 2018
    Co-Authors: Aiman Albatayneh, Dariusz Alterman, Adrian Page, Behdad Moghtaderi
    Abstract:

    The new method described in this paper incorporates the wind effect surrounding the buildings into the external Air Temperature by the use of an equivalent Temperature (called here Tnatural) which produces the same rate of convection heat loss like that with the wind effects included. The Internal Air Temperature of the building can be then calculated using this new external Air Temperature Tnatural.. Simulations using this approach were compared with the real data from four existing housing test modules incorporating a range of walling systems, resulted in an accurate, representative analysis as well as a significantly reducing simulation time.

  • Discrepancies in Peak Temperature Times using Prolonged CFD Simulations of Housing Thermal Performance
    Energy Procedia, 2017
    Co-Authors: Aiman Albatayneh, Dariusz Alterman, Adrian Page, Behdad Moghtaderi
    Abstract:

    Abstract In this paper, CFD analysis was used to determine the Internal Air Temperature over long periods of four full scale housing test modules in Newcastle, Australia exposed to a moderate climate. The influence of different time steps (i.e. 15, 20 30, 35, 40 45, 60, 80, 100, 120, 150, 180 minute intervals) on the discrepancies in peak Temperature for the CFD simulations is discussed in the paper. It was found that the average discrepancies in time for Internal peak Temperatures were between one and five hours compared with the real responses of the testing modules.

  • WARMING ISSUES ASSOCIATED WITH THE LONG TERM SIMULATION OF HOUSING USING CFD ANALYSIS
    Journal of Green Building, 2016
    Co-Authors: Aiman Albatayneh, Dariusz Alterman, Adrian Page, Behdad Moghtaderi
    Abstract:

    ABSTRACT The determination of Internal building Air Temperature has an impact on the design and performance of a building in measuring thermal comfort and heating and cooling loads. There is software to assist with measuring Internal building Air Temperature such as Autodesk CFD simulation. However, the use of Autodesk CFD simulation for the analysis appears to have an issue with simulations extending over a long term (i.e. months or years) as the Internal Air Temperature in a building keeps rising with time. This paper addresses the challenges encountered using CFD simulation in the modelling of a building for long term performance. A new method to overcome the issue of the progressive rising of Internal Air Temperature using two external Air boundaries, one for the external volume (sky boundary) and the other surrounding the building, is suggested in the paper.