scholarly journals Thermal efficiency and cost analysis of solar water heater made in Rwanda

2018 ◽  
Vol 37 (3) ◽  
pp. 1147-1161 ◽  
Author(s):  
Esdras Nshimyumuremyi ◽  
Wang Junqi

Solar water heating is a technology of capturing the energy from the sun's radiation for the purpose of raising the temperature of water from water supply temperature to the desired higher temperature depending on the use. There are many views and discussions on the questions of thermal efficiency of solar water heaters and their associated cost, especially different customers/users want to replace their existing conventional water heating energy by solar water heating systems. In this present paper, a deep investigation has been accomplished to determine thermal efficiency and cost analysis of solar water heater made in Rwanda. During manufacturing of solar water heater, the collector was the main part to emphasize on. The high efficiency of the system was achieved by replacing galvanized iron sheet by aluminum sheet slotted and black painted as an absorber plate. The ambient temperature and average solar radiation of the three sites where solar water heaters are installed were investigated. The used materials, specifications and sizing were discussed in this paper.

2014 ◽  
Vol 3 (1) ◽  
pp. 92-100 ◽  
Author(s):  
Mourad Chikhi ◽  
Rabah Sellami ◽  
Nachida Kasbadji Merzouk

The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For development solar water heaters, the incentive programs are supported by the Algerian government to generalize the using of this kind of energy especially in Sahara. This study is a part of program to develop a new solar water heater in UDES (Algeria). In this research work, the thermal performance of a solar water heater with a mantle heat exchanger is investigated numerically using Comsol Multyphysics software. The objective is to investigate the influence of the mantle heat exchanger thickness on the performance of solar water heaters. The results show, for 160 liters capacity of the solar water heaters tank, the 13mm of the heat exchanger thickness leads to improve the efficiency of the solar water heater.


2004 ◽  
Vol 126 (3) ◽  
pp. 950-956 ◽  
Author(s):  
J. M. Chang

The overall performance rating of a thermosyphon solar water heater should take into consideration its heat removal efficiency during the system application phase. This study employs a precise on-line operation to first identify physical heat removal patterns of a thermosyphon solar water heater, and then develops an empirical model for deriving its characteristic heat removal efficiency. This empirical model is in the form of a logarithmic curve, and has a high data correlation coefficient of 0.889 to 0.967. Based upon the empirical model, this study defines a characteristic heat removal efficiency parameter for thermosyphon solar water heaters. Finally, this study establishes a storage tank design method which enables the characteristic heat removal efficiency of the complete system to be optimized.


Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Brian Norton

AbstractSolar water heating can be considered to be an established mature technology. The achievement of this status is the outcome of over a century of system development that culminated with a flourish of innovation in the last thirty years. Drivers for research and development have been achieving economic viability by devising systems that, for specific applications in particular climate contexts produced more hot water per unit cost. Reductions in both initial capital and installation costs have been achieved as well as in those associated with subsequent operation and maintenance. Research on solar water heating is discussed with the emphasis on overall systems though some key aspects of component development are also outlined. A comprehensive taxonomy is presented of the generic types of solar water heater that have emerged and their features, characteristics and performance are discussed.


Author(s):  
Alexios Papadimitratos ◽  
Sarvenaz Sobhansarbandi ◽  
Vladimir Pozdin ◽  
Anvar Zakhidov ◽  
Fatemeh Hassanipour

This paper presents a novel method of integrating Phase Change Materials (PCMs) and Silicone oil within the Evacuated solar Tube Collectors (ETCs) for application in Solar Water Heaters (SWHs). In this method, heat pipe is immersed inside the phase change material, where heat is effectively accumulated and stored for an extended period of time due to thermal insulation of evacuated tubes. The proposed solar collector utilizes two distinct phase change materials (dual-PCM), namely Tritriacontane paraffin and Erythritol, with melting temperature 72°C and 118°C respectively. The integration of Silicone oil for uniform melting of the PCMs, utilizes the convective heat transfer inside the evacuated tubes, as this liquid polymerized material is well known for its temperature-stability and an excellent heat transfer medium. The operation of solar water heater with the proposed solar collector is investigated during both normal and stagnation (on-demand) operation. The feasibility of this technology is tested via small scale and large scale commercial solar water heaters. Beyond the improved functionality for solar water heater systems, the results from this study show show efficiency improvement of 26% for the normal operation and 66% for the stagnation mode compared with standard solar water heaters that lack phase change materials and silicone oil. The benefit of this method includes improved functionality by delayed release of heat, thus providing hot water during the hours of high demand or when solar intensity is insufficient such in a cloudy day and during night time.


2013 ◽  
Vol 756-759 ◽  
pp. 4492-4496
Author(s):  
Bo Yang Zhang ◽  
Ya Hui Xie ◽  
Shun Xiang Sun

This paper describes the application forms of building integrated with solar energy. We explain a solar water heating system; its solar collectors and water storage tanks are placed together. We discuss another solar water heating system, its solar collectors are placed together but its water storage tanks are placed in every resident's home. This paper also introduces the wall-hung SWH and the application of solar refrigeration and solar heating. At last we analyze the problems of the development of solar water heater integrated with modern architecture.


2013 ◽  
Vol 824 ◽  
pp. 459-466
Author(s):  
M.T. Oladiran ◽  
E. Ossenburg

This paper presents results of an assessment of several solar water units to determine causes of their malfunctioning. A survey of solar water heater (SWH) installations in the Gaborone area, Botswana was carried out to obtain performance characteristics of SWH in the local market. Extensive inspections were performed on both in-service and non-functioning units, problems were diagnosed and pragmatic solutions were proffered. The paper presents some of the discoveries made during the investigation, namely, several units did not last up to the payback period of say 10 to 15 years. The results obtained could provide guidance in selecting operating criteria and suitable system design for solar water heating applications.


2018 ◽  
Vol 4 (2) ◽  
pp. 1-10
Author(s):  
Leandra Altoé ◽  
Delly Oliveira Filho ◽  
Joyce Correna Carlo ◽  
Paulo Marcos Barros Monteiro ◽  
Isabella Theresa Almeida Martins

Several countries have reduced their energy consumption and greenhouse gas emissions levels in buildings by promulgating laws, formulating standards and instituting certification programs. In this context, Brazil launched an energy efficiency certification for buildings in 2009. This study aimed to analyze the economic viability and potential greenhouse gas emissions reductions associated with the use of solar water heaters in a typical Brazilian dwelling. Solar thermal systems were simulated at different energy efficiency levels and shower water flow rates. It was found that the use of solar water heater, as compared with electric heater without a hot water storage, presented internal return rate of approximately 26% per year, simple payback around 4.5 years; net present value about US$ 2,194.00 and cost of conserved energy around US$ 0.12 kWh-1. This study also verified that solar water heater use in a typical Brazilian dwelling reduced emissions compared with electric and gas heating by approximately 95 and 256 kgCO2equivalentyear-1, respectively. The total reduction potential of greenhouse gas emissions by use solar water heaters for the Brazilian residential sector was substantial, around 5.75 million tCO2equivalentyear-1.


2014 ◽  
Vol 1008-1009 ◽  
pp. 58-62
Author(s):  
Bin Yang ◽  
Wei Wang ◽  
De Gong Zuo

This paper introduces a new type of solar water heater——Parabolic trough solar water heater,the biggest feature of the solar water heater is that the parabolic trough reflector can reflect light onto the tube with reflective principles,which may lead to lots of advantages,such as more strong solar energy flux density,fewer losses,fewer tubes used.In a word,the cost is reduced while the performance is guaranteed.On this basis,we built a collector area of about 1.54 square meters of parabolic trough solar water heaters bench and made experiments to test.Instantaneous average efficiency and daily average efficiency of the water heater can be calculated.Efficiency curve can also be generated.Meanwhile we measured the heat loss coefficient of the water heater.The results showed that the daily average efficiency of the parabolic trough concentrating solar collector is between 30% and 50%,while at higher temperatures the collector showed its good insulation properties.


Author(s):  
Gerardo Diaz

Water heating accounts for a significant fraction of the energy consumption in the residential and commercial sectors. A wide variety of water heater configurations are available some of which have higher operating costs than others. The use of solar water heaters is becoming more widespread in many countries usually due to the low operating costs associated with the technology. This paper describes the first implementation of an aluminum-base minichannel solar water heater currently being tested at the University of California Merced.


Inventions ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Fatima Zohra Gargab ◽  
Amine Allouhi ◽  
Tarik Kousksou ◽  
Haytham El-Houari ◽  
Abdelmajid Jamil ◽  
...  

This paper aims to highlight the potential of solar water heater installations in Morocco. The project involves the comparison of active and passive solutions for energy efficiency in buildings. To this end, a numerical simulation model of solar water heater installations is created under TRNsys. Three hot water demand scenarios (Low, Standard, and High) were taken into account for the six climatic zones defined in the Moroccan thermal regulation of constructions. The same software (TRNsys) is used to model a pilot building consisting of 16 flats. Energy efficiency actions have been applied to the building envelope (insulation and glazing) and simulations are made for the six areas. The simulation results comparing energy and financial savings show the influence of subsidized gas prices on solar water heaters’ relevance despite significant energy savings. This work proves that solar water heaters will be a primary obligation for Morocco, taking into account changes in butane gas prices.


Sign in / Sign up

Export Citation Format

Share Document