Modeling and Optimization of a New Configuration of Heat Pipe Parabolic Trough Collector for Solar Water Heating

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Moulay Ahmed Janan ◽  
Mohamed Taqi ◽  
Hamid Chakir

Abstract This work reports the design, numerical modeling, and optimization of a new solar water heater using a heat pipe parabolic trough collector (HPPTC) with low concentration ratio. The heat pipe evaporator is positioned on the focal axis of the reflector, while the condenser section is completely immersed in the water cylindrical tank. The copper wire mesh wick is used as the capillary structure, and the working fluid is distillated water. The proposed model operates in transitory regime under the weather conditions of Casablanca city in Morocco. The intensity of direct solar radiation was estimated by the Kasten model assuming a total sun tracking. The finite difference method has been used to solve governing equations. Several optimization types have been investigated and proved that the optimal configuration is obtained by correctly choosing the geometrical and physical parameters of the system. The thermal efficiency for this configuration with a single heat pipe is about 68.45%. This high performance show that the incorporation of a heat pipe as absorber in a PTC may be a better alternative than conventional heating systems.

In this investigation of multi heat pipe induced in heat exchanger shows the developments in heat transfer is to improve the efficiency of heat exchangers. Water is used as a heat transfer fluid and acetone is used as a working fluid. Rotameter is set to measure the flow rate of cold water and hot water. To maintain the parameter as experimental setup. Then set the mass flow rate of hot water as 40 LPH, 60LPH, 80 LPH, 100LPH, 120 LPH and mass flow rate of cold water as 20 LPH, 30 LPH, 40 LPH, 50 LPH, and 60 LPH. Then 40 C, 45 ºC, 50 ºC, 55 C, 60 ºC are the temperatures of hot water at inlet are maintained. To find some various physical parameters of Qc , hc , Re ,, Pr , Rth. The maximum effectiveness of the investigation obtained from condition of Thi 60 C, Tci 32 C and 100 LPH mhi, 60 LPH mci the maximum effectiveness attained as 57.25. Then the mhi as 100 LPH, mci as 60 LPH and Thi at 40 C as 37.6%. It shows the effectiveness get increased about 34.3 to the maximum conditions.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
C. V. Chachin Vishal ◽  
Jayaraj Krishnan ◽  
G. Venkatesan ◽  
V. Samson Packiaraj Raphael ◽  
Purnima Jalihal

Abstract Conventional desalination technologies like multi stage flashing, multi-effect desalination (MED) using steam as motive fluid can be made sustainable by obtaining the motive steam from solar thermal systems. In this study, a transient simulation has been performed to determine the dissimilitude in pressure drop and dryness fraction, of working fluid in absorber tube due to variation in solar irradiance. A one-dimensional (1D) mathematical model has been developed using matlab for assessing the thermal performance and heat transfer characteristics of a direct steam generating (DSG) parabolic trough collector (PTC) system. It was observed that maximum pressure drop does not occur at maximum quality indicating the working conditions impair the system performance. The developed model was used to overcome this by varying both pressure and mass flowrate of working fluid in accordance to the radiation, results indicated reduction in pressure drop during the same time period for the same exit quality.


Author(s):  
R. Sankar Rao ◽  
S. Bhanu Prakash

Heat pipe is the most widely used heat exchanging device in removal of heat from any given system at a faster rate. The thermal characteristics of heat pipe with single and multi-layered screen mesh wicks have been observed with two working fluids water and acetone. Heat pipe of length 250 mm and 12.7 mm outer diameter, made of copper material is used in all the trials of with and without wick structure. A 100 mesh stainless steel screen wire mesh is chosen as wick structure. Experiments were conducted at different heat loads and various inclinations with 100% fill ratio in evaporator. The performance is measured based on total thermal resistance and overall heat transfer coefficient. The heat pipe is found effective at 60o inclination with acetone as a working fluid and with four layered screen mesh wick. Uncertainty in thermal resistance and heat transfer coefficient is calculated for a heat input of 10W at 0 and 60 inclinations.


2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Djamel Benmenine ◽  
Mokhtar Ghodbane

This study aims to conduct an experimental thermal examination of a parabolic trough collector in Ouargla region at Algeria, which will be used as a solar water heater. The solar collector was manufactured and then experimentally tested, as its theoretical optical performance was estimated at 75.06%, while the values of its true thermal performance are 10.61, 10.68 and 8.85 % for 13 May, 14 May and 15 May. Although its thermal performance is somewhat low, the studied PTC is effective in heating the water, whereas, using a volumetric flow of 0.011 l/s, about 317 liters of water can be heated daily at 42°C, knowing that the daily average consumption of hot water in a typical house is 250 liters because the Ouargla region is strategically located that receives huge amounts of solar irradiance


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