Transient modeling for the prediction of the temperature distribution with phase change material in a salt-gradient solar pond and comparison with experimental data

2019 ◽  
Vol 26 ◽  
pp. 101011 ◽  
Author(s):  
Alireza Jafar Gholi Beik ◽  
Mohammad Reza Assari ◽  
Hassan Basirat Tabrizi
2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Ayoub Gounni ◽  
Mustapha El Alami ◽  
Mohamed Tahar Mabouk ◽  
Abdelhamid Kheiri

Phase change materials (PCMs) used in the building walls constitute an attractive way to reduce the energy consumption and to increase the occupant's thermal comfort. However, there are some challenges to be faced among which the critical one is the PCM layer location allowing the greater heat flux reduction. In this work, the potential of PCM wallboards is evaluated experimentally using a heated reduced scale cavity including walls with or without PCM in a laboratory conditions. The cavity at reduced scale provides the flexibility to test most kinds of wall constructions in real time and allows faster installation and dismantling of the test walls. Three different PCM layer locations inside the walls are examined in terms of heat flux reduction and outside surface temperatures. The results confirm that the PCM layer reduces the peak heat flux compared to a reference wall (wall without PCM). Indeed, the PCM layer hugely affects the peak heat flux when it is placed on the inner face of the walls, near to the heat source. At this location, the peak heat flux reduction, compared to the reference wall, is 32.9%. Furthermore, for numerical validation purpose, the outside overall heat coefficient of the cavity outside walls is determined based on the experimental data.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Suk Goo Yoon ◽  
Young Kwon Yang ◽  
Tae Won Kim ◽  
Min Hee Chung ◽  
Jin Chul Park

General cool roof is effective for reduction of cooling load, but it has a problem of increasing heating load. Therefore, the purpose of this study is to complement the disadvantages of the cool roof system by utilizing phase change characteristics of phase change material (PCM). The study was carried out to verify the thermal performance of the PCM cool roof system by measuring the temperature on the top and bottom of the PCM cool roof system by making a miniature model (600 × 600 × 600 mm). PCM was inserted and not inserted, and the temperature difference according to the finish color (brown and white) was compared. As a result, the plate surface temperature using PCM was lower than that without PCM, and time-lag of temperature increase occurred. As a result of the comparison of temperature according to the finish color (brown and white), white showed a low temperature distribution up to 16.35°C. Even at room temperature, white maintained a low temperature distribution of 5.40°C than brown. The use of PCM cool roof system in roof finishes could lower the surface temperature and keep the room temperature low.


Solar Energy ◽  
2015 ◽  
Vol 122 ◽  
pp. 204-214 ◽  
Author(s):  
Mohammad Reza Assari ◽  
Hassan Basirat Tabrizi ◽  
Alireza Jafar Gholi Beik

Author(s):  
Chen An ◽  
Hui Wang ◽  
Menglan Duan

Abstract As the exploitation of oil and gas gradually enters the deep sea, the low-temperature and high-pressure deep-sea environment poses a huge challenge to the flow protection of pipelines (2014a). In this paper, the phase change material sandwich pipeline which uses phase change heat storage and exothermic to maintain the pipeline temperature is taken as the research object, the heat transfer characteristics of the deep-water phase change material sandwich pipe are studied through the combination of theoretical analysis and numerical simulation (2014b). The main contents include: Firstly, through the establishment of two-dimensional and three-dimensional pipe models, analyzed the temperature distribution along the pipeline and the radial temperature distribution of the pipeline under steady oil flow conditions. Secondly, by using transient heat transfer, the effects of phase change material parameters, the proportion of phase change material in the insulation layer, and the difference in the ratio of phase change materials in the insulation layer on the insulation performance are analyzed to obtain the best results. Insulation material and optimal insulation layer layout; finally, the thermal storage and the phase change conditions of the phase-change material sandwich pipe is studied under the re-starting condition. The results show that the effective holding time of the phase change material insulation layer is close to 1.4 times that the non-phase change material insulation layer, and the melting point size has little effect on the insulation material. The closer the phase change material is to the inner tube, the better the insulation effect. This study provide guidance for the design and utilization of phase change material sandwich pipe.


2020 ◽  
pp. 014459872097416
Author(s):  
Hua Wang ◽  
Ma Xiaomeng ◽  
Zhang Liugang ◽  
Xinmin Zhang ◽  
Yanyang Mei ◽  
...  

In this paper, the effect of adding the composite PCM (Phase Change Material) heat storage capsules to the heat storage layer of the salt gradient solar pond on the thermal performance of the solar pond was studied numerically and experimentally. Based on the program-controlled temperature simulation of the solar pond experimental platform, the effect of adding the composite PCM (48–50°C and 58–60°C melting point paraffin) heat storage capsules on the solar pond temperature and stability was studied, and a numerical simulation model was established to be compared by the experimental results. The results showed that the experimental temperature was consistent with the simulation results; the solar pond with PCM capsules had a smaller temperature change range than the conventional solar pond during the phase change process, but it did not have such effect in the non-phase transition process; in terms of flow, the addition of the PCM phase change units could reduce the flow rate of the heat storage zone, and the PCM with a larger latent heat had a more obvious suppression effect on the flow. Therefore, within a certain temperature range, adding PCM units to the solar pond had a positive effect on maintaining the stable temperature and stability of solar pond.


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