scholarly journals Optimization of a New Phase Change Material Integrated Photovoltaic/Thermal Panel with The Active Cooling Technique Using Taguchi Method

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1022 ◽  
Author(s):  
Xiaohong Liu ◽  
Yuekuan Zhou ◽  
Chun-Qing Li ◽  
Yaolin Lin ◽  
Wei Yang ◽  
...  
Keyword(s):  
Phase Change ◽  
Water Temperature ◽  
Mass Flow Rate ◽  
Phase Change Material ◽  
Flow Rate ◽  
Cooling Water ◽  
Optimal Combination ◽  
Water Pipe ◽  
Cooling Water Temperature ◽  
Change Material

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.

scholarly journals Application of Phase Change Material and Artificial Neural Networks for Smoothing of Heat Flux Fluctuations

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3531
Author(s):  
Tomasz Tietze ◽  
Piotr Szulc ◽  
Daniel Smykowski ◽  
Andrzej Sitka ◽  
Romuald Redzicki
Keyword(s):  
Neural Networks ◽  
Heat Flux ◽  
Artificial Neural Networks ◽  
Phase Change ◽  
Mass Flow Rate ◽  
Phase Change Material ◽  
Flow Rate ◽  
Smoothing Effect ◽  
Artificial Neural ◽  
Change Material

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%.

scholarly journals ŠILUMNEŠIO DEBITO ĮTAKOS FAZINIO VIRSMO MEDŽIAGOS VEIKIMUI TYRIMAS / INVESTIGATION OF THE INFLUENCE OF MASS FLOW RATE ON PHASE CHANGE MATERIAL BEHAVIOUR

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5 ◽  
Author(s):  
Saulius Pakalka ◽  
Kęstutis Valančius ◽  
Matas Damonskis
Keyword(s):  
Experimental Study ◽  
Phase Change ◽  
Mass Flow Rate ◽  
Phase Change Material ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Transfer Fluid ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Change Material

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.

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

2007 ◽  
Author(s):  
Yu Rao ◽  
Frank Dammel ◽  
Peter Stephan
Keyword(s):  
Phase Change ◽  
Mass Flow Rate ◽  
Phase Change Material ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Conditions ◽  
Cooling Performance ◽  
Microencapsulated Phase Change Material ◽  
Wall Heating ◽  
Change Material

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.

Using a Novel Phase Change Material-Based Cooling Tower for a Photovoltaic Module Cooling

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Nasrin Abdollahi ◽  
Masoud Rahimi
Keyword(s):  
Surface Temperature ◽  
Phase Change ◽  
Phase Change Material ◽  
Output Power ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Helical Tube ◽  
Change Material

Abstract This paper presents an experimental investigation on a hybrid solar system, including a water-based photovoltaic (PV) solar module and a phase change material (PCM)-based cooling tower, for cooling of the module. Elimination of heat from the PV module was performed by the use of water in the back of the panel. The PCM-based cooling tower was used as a postcooling system. A composite oil consisting of 82 wt% coconut oil and 18 wt% sunflower oil has been used as a novel phase change material in the cooling tower. The helical tubes of the cooling tower were fabricated in two different curvature ratios of 0.054 and 0.032. The experiments were performed at three different water flow rates of 11.71, 16.13, and 19.23 mL/s. The cooling performance evaluation was carried out using the average surface temperature and output power of the photovoltaic panel. The results indicated that diminution of the average PV surface temperature relative to the reference temperature was 34.01 and 32.36 °C at a water flow rate of 19.23 mL/s for the cooling systems with helical tube curvature ratios 0.054 and 0.032, respectively. Furthermore, the highest electric output power was achieved for the cooling system with a helical tube curvature ratio of 0.054 at a water flow rate of 19.23 mL/s.

scholarly journals Numerical Performance Investigation of Hybrid PV/Thermal System

2018 ◽  
Vol 7 (4.19) ◽  
pp. 818
Author(s):  
Kadhim K. Idan Al-Chlaihawi ◽  
Dhafer A. Hamzah ◽  
Ahmed K. Zarzoor ◽  
Yousif M. Hasan
Keyword(s):  
Solar Radiation ◽  
Water Temperature ◽  
Flow Rate ◽  
Cooling Water ◽  
Electrical Performance ◽  
Flow Rates ◽  
Electrical Efficiency ◽  
Cooling Water Temperature ◽  
Present Work Deal ◽  
Numerical Performance

Promoting reduction of PV temperature plays crucial role in increasing electrical performance. The present work deal with different types of absorber shape for analysing heat transfer phenomena. Serpentine and spiral absorber are using to verify this purpose with different boundary conditions of inlet mass flow rate and inlet temperatures.The recent study was conducted to evaluate the effect of some operating and designing parameters such as solar radiation levels, flow rates, absorber shape and cooling water temperature on the performance of PVT system numerically. Performance of PVT system determined by thermal efficiency, electrical efficiency and the summation of both known as total or PVT efficiency. Solar radiation ranging from 500 W/m2 to1000 W/m2 was introduced and at each, flow rates of water ranging from 0.016 kg/s to 0.05 kg/s. The results show that the performance of PVT increases with a flow rate at all radiation levels. Also the spiral flow absorber gives a higher performance than serpentine absorber where the value of  of spiral absorber is increased by about 5.2% compared to the value of serpentine absorber, on the other hand, the rate of heat loss ( decreased by about 10%.Increasing initial cooling water temperature degrades electrical efficiency of PVT system.  

Forced Flow and Convective Heat Transfer of Phase Change Material Slurry in the Heat Exchangers

2010 ◽  
Author(s):  
Peng Zhang ◽  
Zhiwei Ma ◽  
Ruzhu Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Rate ◽  
Tetrabutylammonium Bromide ◽  
Forced Flow ◽  
Experimental Investigations ◽  
Cooling Power ◽  
Change Material

The application of phase change material slurry to the refrigeration and air conditioning system opens a new way for energy saving and reduction of the quantity of refrigerant in the system, because it can serve as both the energy storage and transportation media in the secondary loop which is responsible for distributing the cooling power. In the present study, the experimental investigations of the forced flow and heat transfer characteristics of Tetrabutylammonium Bromide (TBAB in abbreviation) clathrate hydrate slurry (CHS) in both the plate heat exchanger (PHE) and double-tube heat exchanger (DHE) are carried out. It is found out that the pressure drop in the PHE is about 5–50 kPa at the flow rate of 2–14 L/min and is about 2–30 kPa at the flow rate of 3–14 L/min, which is nearly 2 times of that of the chilled water. The overall heat transfer coefficient is in the range of 2500–5000 W/(m2K) for TBAB CHS in the PHE and is about 1500–3500 W/(m2K) in the DHE, which are both higher than that of TBAB aqueous solution flow because of the involvement of the phase change of TBAB CHS.

scholarly journals Effect of uniform and variable fin height on charging and discharging of phase change material in a horizontal cylindrical thermal storage

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1981-1988 ◽  
Author(s):  
Ramalingam Senthil
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Rate ◽  
Cold Water ◽  
Copper Tube ◽  
Heat Transfer Fluid ◽  
Outer Diameter ◽  
The One ◽  
Change Material

The effect of fin profile on melting of phase change material (PCM) is presented. The test section contains an acrylic tube of 50 mm outer diameter and a copper tube of 16 mm outer diameter and a length of 1000 mm each. Both tubes are kept coaxially. The heat transfer fluid (HTF) flows through the copper tube. The PCM is paraffin wax and filled in the annular region. The considered fin profiles are the uniform and variable fin heights of circular, triangular and elliptical profiles. Fins are fixed on the HTF tube and protruded into the PCM. The total fin surface area is maintained same among the fin profiles and the fin arrangements. The one-third of the storage is provided with increasing fin height of 2- 3 mm to melt the settled solid PCM. The hot and cold water is used to charge and discharge the PCM, respectively. Experiments are performed by the hot and cold-water inlet temperatures of 70 ?C and 28 ?C at a flow rate of 0.5 kg per minute. A faster and effective heat transfer from HTF to PCM and vice-versa is investigated. The variable elliptical fins showed faster charging and discharging by 25% and 20%, respectively, than the variable circular fins. The variable elliptical fins showed faster charging and discharging by 11.8% and 11% than the variable triangular fins. The charging and discharging efficiency of 80% and 74% are observed for the elliptical fin profiles.

scholarly journals Impact of the cold end operating conditions on energy efficiency of the steam power plants

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 53-66 ◽  
Author(s):  
Mirjana Lakovic ◽  
Mladen Stojiljkovic ◽  
Slobodan Lakovic ◽  
Velimir Stefanovic ◽  
Dejan Mitrovic
Keyword(s):  
Energy Efficiency ◽  
Power Plant ◽  
Water Temperature ◽  
Flow Rate ◽  
Power Plants ◽  
Cooling Water ◽  
Operating Conditions ◽  
Steam Boiler ◽  
Steam Power ◽  
Cooling Water Temperature

The conventional steam power plant working under the Rankine Cycle and the steam condenser as a heat sink and the steam boiler as a heat source have the same importance for the power plant operating process. Energy efficiency of the coal fired power plant strongly depends on its turbine-condenser system operation mode. For the given thermal power plant configuration, cooling water temperature or/and flow rate change generate alterations in the condenser pressure. Those changes have great influence on the energy efficiency of the plant. This paper focuses on the influence of the cooling water temperature and flow rate on the condenser performance, and thus on the specific heat rate of the coal fired plant and its energy efficiency. Reference plant is working under turbine-follow mode with an open cycle cooling system. Analysis is done using thermodynamic theory, in order to define heat load dependence on the cooling water temperature and flow rate. Having these correlations, for given cooling water temperature it is possible to determine optimal flow rate of the cooling water in order to achieve an optimal condensing pressure, and thus, optimal energy efficiency of the plant. Obtained results could be used as useful guidelines in improving existing power plants performances and also in design of the new power plants. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI151102198E">10.2298/TSCI151102198E</a><u></b></font>

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