Phase Change Materials as a Modifier of Ageing Cement Concrete in Hot and Dry Climate

2013 ◽  
Vol 804 ◽  
pp. 129-134 ◽  
Author(s):  
Mahmoud Hsino ◽  
Jerzy Pasławski
Keyword(s):  
Middle East ◽  
Phase Change ◽  
Air Temperature ◽  
Large Amplitude ◽  
Phase Change Materials ◽  
Cement Concrete ◽  
Thermal Peak

This paper is devoted to the use of Phase Change Materials as a cement concrete modifier in Middle East climate. Due to large amplitude of daily air temperature in these conditions, Phase Change Materials can be used to reduce the dynamic of thermal peak in an ageing concrete. Partial results of studies to determine the influence of various factors on the effects of modifications are presented

scholarly journals Energy Saving and Charging Discharging Characteristics of Multiple PCMs Subjected to Internal Air Flow

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 275
Author(s):  
Ahmed J. Hamad
Keyword(s):  
Phase Change ◽  
Energy Saving ◽  
Air Temperature ◽  
Temperature Control ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Heating System ◽  
Air Heating ◽  
Room Model ◽  
Model Temperature

One essential utilization of phase change materials as energy storage materials is energy saving and temperature control in air conditioning and indirect solar air drying systems. This study presents an experimental investigation evaluating the characteristics and energy savings of multiple phase change materials subjected to internal flow in an air heating system during charging and discharging cycles. The experimental tests were conducted using a test rig consisting of two main parts, an air supply duct and a room model equipped with phase change materials (PCMs) placed in rectangular aluminum panels. Analysis of the results was based on three test cases: PCM1 (Paraffin wax) placed in the air duct was used alone in the first case; PCM2 (RT–42) placed in the room model was used alone in the second case; and in the third case, the two PCMs (PCM1 and PCM2) were used at the same time. The results revealed a significant improvement in the energy savings and room model temperature control for the air heating system incorporated with multiple PCMs compared with that of a single PCM. Complete melting during the charging cycle occurred at temperatures in the range of 57–60 °C for PCM1 and 38–43 °C for PCM2, respectively, thereby validating the reported PCMs’ melting–solidification results. Multiple PCMs maintained the room air temperature at the desired range of 35–45.2 °C in the air heating applications by minimizing the air temperature fluctuations. The augmentation in discharging time and improvement in the room model temperature using multiple PCMs were about 28.4% higher than those without the use of PCMs. The total energy saving using two PCMs was higher by about 29.5% and 46.7% compared with the use of PCM1 and PCM2, respectively. It can be concluded that multiple PCMs have revealed higher energy savings and thermal stability for the air heating system considered in the current study.

Application Study of Nanoparticle-Enhanced Phase Change Material in Ceiling Board

2010 ◽  
Vol 150-151 ◽  
pp. 723-726 ◽  
Author(s):  
Cha Xiu Guo
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Air Temperature ◽  
Indoor Air ◽  
Phase Change Materials ◽  
Application Study ◽  
Alumina Nanoparticle ◽  
Phase Fields ◽  
Change Material ◽  
Porosity Model

The application of phase change materials (PCMs) is very promising in buildings because it allows the storage and discharge of considerable quantities of cooling and heating energy, dumping the air temperature swings within the building so that the indoor air temperature is closer to the desired temperature for a longer period of time. In order to account for the good characteristics of Alumina nanoparticle-in-paraffin as phase change material, based on enthalpy-porosity model and numerical analysis, detailed phase fields and heat flux are obtained, compared with that of pure paraffin. And study demonstrates that room with ENPCM ceiling is a good way of saving cool energy in summer.

scholarly journals Peak indoor air temperature reduction for buildings in hot-humid climate using phase change materials

2020 ◽  
Vol 22 ◽  
pp. 100762
Author(s):  
Zeyad Amin Al-Absi ◽  
Mohd Isa Mohd Hafizal ◽  
Mazran Ismail ◽  
Ahmad Mardiana ◽  
Azhar Ghazali
Keyword(s):  
Phase Change ◽  
Air Temperature ◽  
Indoor Air ◽  
Phase Change Materials ◽  
Humid Climate ◽  
Temperature Reduction ◽  
Hot Humid Climate

scholarly journals Eco-Friendly and Economical Solar Heater Design Using Internal Structure and Phase Change Materials

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7423
Author(s):  
Jihu Lee ◽  
Sung-Hun Son ◽  
Kibum Kim
Keyword(s):  
Phase Change ◽  
Internal Structure ◽  
Air Temperature ◽  
Phase Change Materials ◽  
Operating Conditions ◽  
Internal Space ◽  
Solar Air Heater ◽  
Air Heater ◽  
Solar Heater ◽  
Heater Design

Indoor heating systems currently used are highly dependent on fossil fuels; hence, it is urgent to develop a new heating system to achieve carbon zero-emission. A solar air heater is eco-friendly because it generates nearly zero greenhouse gases. In this study, a parametric study was conducted for optimizing solar air heater design applicable to indoor heating. Installing the internal structure in the solar heater changes the interior flow characteristic, resulting in the air temperature increased by about 14.2 K on average compared to the heater without the internal structure. An additional case study was carried out to optimize the ideal quantity of phase change materials (PCM) in terms of mass fraction and heat capacity for various operating conditions. An excessive amount of PCM (e.g., 66% of the storage space filled with PCM) deteriorates the performance of the air heater unless the entire PCM could be melted during the daytime. After heating, the air temperature was maintained the longest when only 33% of the internal space was filled with PCM. The solar air heater can fully replace or partly assist a conventional heater for indoor heating, and it could reduce approximately 0.6 tCO2 per year.

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