Experiments on the Cooling Performance of Microencapsulated Phase Change Material Suspension Flow in Rectangular Minichannels

Author(s):  
Yu Rao ◽  
Frank Dammel ◽  
Peter Stephan

Comparative experiments were conducted in order to investigate the effects of the mass flow rate and wall heating flux on the cooling performance of water-based suspensions of microencapsulated phase change material (MEPCM) flowing through rectangular minichannels. MEPCM particles with an average size of 4.97 μm were used to form suspensions with mass concentrations ranging from 0% to 20%. The comparative experiments were performed for varying mass flow rates in the laminar region and varying thermal conditions. It was found out that the mass flow rate and wall heating flux play a significant role in the cooling performance of MEPCM suspensions. It is believed that the decreased thermal conductivity of MEPCM suspensions with the concentration and the different thermally developing flow patterns are mainly responsible for the dependence of the cooling performance of MEPCM suspensions of those parameters.

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5 ◽  
Author(s):  
Saulius Pakalka ◽  
Kęstutis Valančius ◽  
Matas Damonskis

The paper presents an experimental study of the influence of heat transfer fluid (HTF) mass flow rate on phase change materials (PCM) behaviour. The experimental study was performed on a specially designed test bench. Research object – PCM based thermal energy storage unit which consists of a stainless steel tank with dual circuit tube-fin copper heat exchanger. The tank (storage volume) was filled with phase change material RT82. The experiment was carried out using three different mass flow rates of HTF: high – 0.25 kg/s, medium – 0.125 kg/s, low – 0.05 kg/s. The analysis showed that in the case of high and medium mass flow rates the melting/solidification process highly depends on the temperature of inlet HTF. Influence of mass flow rate is higher in the case of low mass flow rate.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3531
Author(s):  
Tomasz Tietze ◽  
Piotr Szulc ◽  
Daniel Smykowski ◽  
Andrzej Sitka ◽  
Romuald Redzicki

The paper presents an innovative method for smoothing fluctuations of heat flux, using the thermal energy storage unit (TES Unit) with phase change material and Artificial Neural Networks (ANN) control. The research was carried out on a pilot large-scale installation, of which the main component was the TES Unit with a heat capacity of 500 MJ. The main challenge was to smooth the heat flux fluctuations, resulting from variable heat source operation. For this purpose, a molten salt phase change material was used, for which melting occurs at nearly constant temperature. To enhance the smoothing effect, a classical control system based on PID controllers was supported by ANN. The TES Unit was supplied with steam at a constant temperature and variable mass flow rate, while a discharging side was cooled with water at constant mass flow rate. It was indicated that the operation of the TES Unit in the phase change temperature range allows to smooth the heat flux fluctuations by 56%. The tests have also shown that the application of artificial neural networks increases the smoothing effect by 84%.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1022 ◽  
Author(s):  
Xiaohong Liu ◽  
Yuekuan Zhou ◽  
Chun-Qing Li ◽  
Yaolin Lin ◽  
Wei Yang ◽  
...  

This paper investigates the energy performances of a hybrid system composed of a phase change materials-ventilated Trombe wall (PCMs-VTW) and a photovoltaic/thermal panel integrated with phase change material (PV/T-PCM). Equivalent overall output energy (QE) was proposed for energy performance evaluation regarding different energy forms, diversified conversions and hybrid thermal storages. This study focuses on parameters’ optimization of the PV/T-PCM system and parameters in the PCMs-VTW are kept optimal. Based on the experimentally validated numerical modelling, nine trial experiments have been conducted following Taguchi L9 (34) standard orthogonal array. The higher the better concept was implemented and the optimal combination of operating parameters was thereafter identified by using signal-to-noise (S/N) ratio and Analysis of Variance (ANOVA) method. The results show that QE is highly dependent on the mass flow rate, followed by the diameter of active cooling water pipe. However, the inlet cooling water temperature and the thickness of PCM have limited influence on QE. The optimal combination of each factor was identified as B3A3C2D1 (mass flow rate of 1 kg/s, diameter of water pipe of 0.6 m, inlet cooling water temperature of 15 °C and the thickness of PCM of 20 mm) with the highest QE of 20,700 kWh.


2020 ◽  
Vol 56 (3) ◽  
pp. 2176-2191
Author(s):  
Jun Li ◽  
Xiaoyun Zhu ◽  
Huichang Wang ◽  
Pengcheng Lin ◽  
Lisi Jia ◽  
...  

2021 ◽  
Vol 16 ◽  
pp. 155892502110295
Author(s):  
Abdus Shahid ◽  
Solaiman Miah ◽  
Abdur Rahim

Jute bags are widely used to carry food grains and other materials that may be prone to quality deterioration due to thermal fluctuation. Thermal and moisture properties play a significant role in the packaging materials in the form of a container. This study deals with the effect of microencapsulated phase change material (MPCM) with hydrophobic binder on thermal and moisture management properties of jute fabric. Jute fabric was treated with MPCM by pad-dry-cure method. The treated sample was characterized by thermogravimetric analysis (TGA), differential scanning colorimeter (DSC), scanning electron microscope (SEM), moisture management tester (MMT), and air permeability tester. The results revealed that MPCM treated jute fabric shows greater thermal stability and heat absorption ability of 10.58 J/g while changing from solid to liquid phase. The SEM image ensures even distribution of MPCMs on fabric surface and surface roughness was also observed using image processing software. The air permeability was found to decrease whereas the water repellency enhanced in the developed sample.


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