Numerical thermal evaluation of laminated binary microencapsulated phase change material drywall systems

Abstract

Microencapsulated phase change materials (MEPCMs) have the potential for energy storage applications in buildings. However, current MEPCMs are limited by their singular phase change transitional temperatures and are therefore unable to satisfy all year seasonal energy storage applications. This study was focused on numerically assessing the energy saving potential of a binary MEPCM drywall system which is capable of operating within two different phase change transitional temperature ranges. In this study, Ansys Fluent and the ESP-r simulation tools were employed because Fluent could offer a detailed quantification of the temperature changes within the composite drywall system and ESP-r has the capability of thermal modelling of phase change materials at whole building scale by using annual weather data as boundary conditions. The Fluent simulation results demonstrated that the thermal energy charge time and thermal energy charge/discharge amount of the binary MEPCM drywall were significantly increased when the MEPCM thickness increased from 1 mm to 5 mm, and the 5 mm thick layer had adequate capacity to balance the thermal energy during day and night. The ESP-r results showed that for the hot period in Hangzhou (China), the 5 mm thick binary MEPCM drywall was able to achieve a maximum peak air temperature reduction of about 6.7℃ and to increase the number of hours the indoor air temperatures were within the 21-28C range by about 12% in Blinded ManuscriptClick here to view linked References comparison with other drywalls. Experimental evaluation is therefore being recommended to verify the full practical potential of MEPCMs with two phase change temperature ranges.Keywords: binary microencapsulated phase change material drywall, thermal performance, energy storage, whole building simulation of MEPCMs, two phase change temperature ranges. Highlights: The mm binary MEPCM drywall was able to balance thermal energy for day and night. The binary MEPCM drywall had better performance than the single MEPCM. The binary MEPCM drywall was able to reduce the peak indoor temperature by 6.7C.  Indoor temperatures were improved by 12% with the 5 mm binary MEPCM drywall. Nomenclature Cp Specific heat (kJ/kg•K) g Heat generation rate (W/m 3 ) P H Total enthalpy of the MEPCM (kJ/kg)

Temperature Control to Improve Performance of Hempcrete-Phase Change Material Wall Assemblies in a Cold Climate

“…For the hysteresis effect with complete cycles of melting-freezing phase change, temperature change with time determines the liquid fraction equation used in the source term, as shown in Equations ( 4) and (5).…”

“…Hence, a hysteresis model is used to simulate the hysteresis effect and the transition between melting and freezing curves in cases of incomplete phase change, as shown in Figure 4. The hysteresis model and the liquid fraction transition curves are developed using the 0:00 1:00 For the hysteresis effect with complete cycles of melting-freezing phase change, temperature change with time determines the liquid fraction equation used in the source term, as shown in Equations ( 4) and (5).…”

“…In passive applications, PCMs are typically embedded into the building fabrics of walls, floors, roofs, fenestration, façade, shutter, and shading systems without relying on auxiliary equipment, which increases the envelope's thermal storage capacity [1,2]. PCM is integrated into the building fabrics through different approaches such as PCM-enhanced covering materials, including plasterboards, wallboards or gypsum boards [3][4][5], concrete [6,7], ceramics [8,9], microencapsulated PCM panels [10][11][12], multi PCM structure [13][14][15][16], and PCM-impregnated insulations [17][18][19]. The initial capital cost of PCM is still high [2,20].…”

Development of Composite Microencapsulated Phase Change Materials for Multi-Temperature Thermal Energy Storage

“…One notable advancement in this field was made by Su et al [18], who found out that laminated binary MEPCM drywall could perform thermally better than a single MEPCM drywall system across different seasons. Huang et al [19] also synthesized multiple formstable PCMs based on confining ethylene glycole distearate (EGDS) within epoxy-based polymer matrix through photo-initiated polymerization.…”

Preparation of High Thermo-Stability and Compactness Microencapsulated Phase Change Materials with Polyurea/Polyurethane/Polyamine Three-Composition Shells through Interfacial Polymerization

“…Microencapsulated phase change materials (MicroPCMs) have expanded the application and market prospects of phase change materials [ 1 , 2 , 3 , 4 ], which include textiles, dyeing and printing [ 5 , 6 , 7 ], building energy saving [ 8 , 9 , 10 ], microencapsulated phase change slurry [ 11 , 12 , 13 ] and composite foam [ 14 , 15 , 16 ].…”