scholarly journals Exergy Analysis of Serpentine Thermosyphon Solar Water Heater

2018 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
Muhammad Hasan ◽  
Md. Mahadi ◽  
Takahiko Miyazaki ◽  
Shigeru Koyama ◽  
Kyaw Thu
2020 ◽  
pp. 343-343
Author(s):  
Sathyakala Ponnusamy ◽  
Sundara Sai Gangadharan ◽  
Balaji Kalaiarasu

This study investigates the hidden thermal losses of glass plate, collector plate, water pipe and storage tank of solar water heater in the process of energy conversion. The present non-conventional energy methods are insufficient, whereas the exergy analysis provides a remarkable solution. Thus, employing the exergy analysis, entropy generation, exergy destruction and exergy efficiency of each subsystem of solar water heater are computed. The obtained results showed that the entropy generation and exergy destruction are high during the heat transfer in each subsystem. Henceforth, the existing solar water heater design is modified placing hexagonal honeycomb structure between the glass plate and the collector plate and also water pipe is insulated to trap huge amount of solar energy. The proposed design exhibits improved exergy efficiency when compared with the existing model, which enhances the performance of the system.


2020 ◽  
Vol 67 (1) ◽  
pp. 142-147
Author(s):  
Alina A. Aleksandrova ◽  
Maksim S. Zhuzhin ◽  
Yuliya M. Dulepova

Energy saving today is an integral part of the development strategy of agricultural organizations. Considerable attention is paid to the modernization and automation of technological processes in agricultural enterprises, which can improve the quality of work and reduce the cost of production. The direction of modernization is to reduce the consumption of electric energy by improving the water treatment system in livestock complexes. (Research purpose) The research purpose is to determine the potential of solar energy used in the Nizhny Novgorod region and to determine the possibility of its use for water heating in livestock complexes and to consider the cost-effectiveness of using a device to heat water through solar energy. (Materials and methods) Authors used an improved algorithm of Pixer and Laszlo, applied in the NASA project «Surface meteorology and Energy», which allows to calculate the optimal angle of inclination of the device for heating water. (Results and discussion) Designed a mock-up of a livestock complex with a solar water heater installed on the roof, protected by patent for invention No. 2672656. A mathematical model was designed experimentally to predict the results of the plant operation in non-described modes. (Conclusions) The article reveales the optimal capacity of the circulation pump. Authors have created a mathematical model of the device that allows to predict the water heating in a certain period of time. The article presents the calculations on the energy and economic efficiency of using a solar water heater. An electric energy saving of about 30 percent, in the economic equivalent of 35 percent.


2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Felipe A. S. Silva ◽  
Luis Júnior ◽  
José Silva ◽  
Sandilya Kambampati ◽  
Leandro Salviano

AbstractSolar Water Heater (SWH) has low efficiency and the performance of this type of device needs to be improved to provide useful and ecological sources of energy. The passive techniques of augmentation heat transfer are an effective strategy to increase the convective heat transfer coefficient without external equipment. In this way, recent investigations have been done to study the potential applications of different inserts including wire coils, vortex generators, and twisted tapes for several solar thermal applications. However, few researchers have investigated inserts in SWH which is useful in many sectors where the working fluid operates at moderate temperatures. The longitudinal vortex generators (LVG) have been applied to promote heat transfer enhancement with a low/moderate pressure drop penalty. Therefore, the present work investigated optimal geometric parameters of LVG to enhance the heat transfer for a SWH at low Reynolds number and laminar flow, using a 3D periodical numerical simulation based on the Finite Volume Method coupled to the Genetic Algorithm optimization method (NSGA-II). The LVG was stamped over a flat plate inserted inside a smooth tube operating under a typical residential application corresponding to Reynolds numbers of 300, 600, and 900. The geometric parameters of LGV were submitted to the optimization procedure which can find traditional LVG such as rectangular-winglet and delta-winglet or a mix of them. The results showed that the application of LGVs to enhance heat transfer is an effective passive technique. The different optimal shapes of the LVG for all Reynolds numbers evaluated improved more than 50% of heat transfer. The highest augmentation heat transfer of 62% is found for the Reynolds number 900. However, the best thermo-hydraulic efficiency value is found for the Reynolds number of 600 in which the heat transfer intensification represents 55% of the pressure drop penalty.


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