scholarly journals An exergy analysis for overall hidden losses of energy in solar water heater

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.

1992 ◽  
Vol 114 (3) ◽  
pp. 188-193 ◽  
Author(s):  
H. A. Walker ◽  
J. H. Davidson

Entropy generated by operation of a two-phase self-pumping solar water heater under Solar Rating and Certification Corporation rating conditions is computed numerically in a methodology based on an exergy cascade. An order of magnitude analysis shows that entropy generation is dominated by heat transfer across temperature differences. Conversion of radiant solar energy incident on the collector to thermal energy within the collector accounts for 87.1 percent of total entropy generation. Thermal losses are responsible for 9.9 percent of total entropy generation, and heat transfer across the condenser accounts for 2.4 percent of the total entropy generation. Mixing in the tempering valve is responsible for 0.7 percent of the total entropy generation. Approximately one half of the entropy generated by thermal losses is attributable to the self-pumping process. The procedure to determine total entropy generation can be used in a parametric study to evaluate the performance of two-phase hot water heating systems relative to other solar water heating options.


2018 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
Muhammad Hasan ◽  
Md. Mahadi ◽  
Takahiko Miyazaki ◽  
Shigeru Koyama ◽  
Kyaw Thu

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.


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