Experimental study on the performance of a novel solar water heating system with and without PCM

Khaled

Journal of Energy Storage

et al. 2021

207

Researchers worldwide are investigating thermal energy storage, especially phase change materials, for their substantial benefits in improving energy efficiency, sustaining thermal comfort in buildings and contributing to the reduction of environmental pollution. Residential buildings and commercial constructions, being dependent on heating and cooling systems, are subjected to the utilization of PCM technology through several applications. The current study presents a state-of-the-art review that covers recent literature on thermal energy storage systems utilizing PCMs for buildings. The reviewed applications are heating and hybrid applications, that are categorized as passive and active systems. A summary of the PCMs used, applications, thermo-physical properties and incorporation methods are presented as well. The study emphasizes the promising effectiveness of PCM in building heating applications, and highlights the significance of PCM system hybridization. The study shows that experimental investigations on commercial constructions, and hybrid systems development and optimization, are still required. Finally, possible combinations of active and passive heating applications with their auspicious benefits in terms of energy efficiency augmentation, are recommended. Highlights  State-of-the-art review on PCM building applications for heating and hybrid systems  Active and Passive classification for heating and hybrid systems  Challenges altering the PCM technology for energy-efficient buildings are addressed  Hybridization of active and passive systems forms a potential method toward NZEB

Section: Hybrid Active Methodsmentioning

confidence: 99%

A review on phase change materials for thermal energy storage in buildings: Heating and hybrid applications

Khaled

Journal of Energy Storage

et al. 2021

207

“…Within a SWH, different locations for the TES system with PCMs have been proposed in previous studies [11][12][13][14]. The typical configurations include PCMs placed in four locations: within the solar thermal collector [11], in a coupled PCM module between the collector and the water storage tank [15], within the water storage tank [16], and in a heat exchanger in a tankless configuration [10].…”

Section: Of 23mentioning

confidence: 99%

A Redesign Methodology to Improve the Performance of a Thermal Energy Storage with Phase Change Materials: A Numerical Approach

James

Rosario

et al. 2022

Energies

In recent years, phase change materials (PCMs) have been presented as a suitable alternative for thermal energy storage (TES) systems for solar water heater (SWH) applications. However, PCMs’ low thermal conductivity and the high dependence on external conditions are the main challenges during the design of TES systems with PCMs. Design actions to improve the performance of the TES systems are crucial to achieve the necessary stored/released thermal energy and guarantee the all-day operation of SWHs under specific system requirements. In this study, a TES with PCM in the configuration of a heat exchanger was redesigned, focused on achieving two main targets: an outlet water temperature over 43 °C during discharging time (15 h) and efficiency over 60% to supply the hot water demand of two families (400 L). A four-step redesign methodology was proposed and implemented through numerical simulations to address this aim. It was concluded that the type, encapsulation shape, and amount of PCM slightly impacted the system’s performance; however, selecting a suitable sensible heat storage material had the highest impact on meeting the system’s targets. The redesigned TES reached 15 operating hours with a minimum outlet water temperature of 45.30 °C and efficiency of 76.08%.

International Journal of Photoenergy

“…The benefit of using different types of phase change materials (PCMs) had also been studied in several studies to improve the performance of solar collectors [16][17][18]. The experiment is with a SWH coupled with an oscillating heat pipe and a PCM [19]. They confirmed that the PCM had reduced the output fluctuations by 30% and increased the outlet water temperature to 50°C.…”

Section: Introductionmentioning

confidence: 98%

Energy and Economic Analysis of Curved, Straight, and Spiral Flow Flat-Plate Solar Water Collector

Muthuraman¹,

Shankar²,

Nassa³

et al. 2021

In this work, the solar water collector flow tube geometry is modified as curved and spiral to enhance the system’s performance. The investigation is carried out experimentally under the meteorological conditions of the Kovilpatti region (9°10 ′ 0 ″ N, 77°52 ′ 0 ″ E), Tamil Nadu, India. The flow pipes of the solar water heater are made of copper material which has higher thermal conductivity to recover the water heat as thermal energy. The influence of the mass flow rate (MF) on the flow pipes with respect to the surface temperature for various configurations of the flow tubes is investigated. The two MFs of 0.0045 kg/s and 0.006 kg/s are tested. The MF of 0.006 kg/s yields the maximum efficiency of 73% compared to the other MF. The straight, curved, and spiral tubes yielded the maximum efficiency of 58%, 62%, and 69%, respectively, at 0.0045 kg/s. Similarly, the MF of 0.006 kg/s obtained an efficiency of 62%, 65%, and 73% for straight, curved, and spiral flow tubes, respectively. The economics and exergy of the system are analyzed. The maximum exergy efficiency of the collector is estimated to be 32% for the MF of 0.0045 kg/s for the spiral flow collector, and for the 0.006 kg/s MF, the obtained exergy efficiency is 27% for the spiral flow water heater. The economic analysis revealed that the expense is $0.0608 and $0.0512 worth of hot water produced for the domestic space heating.