Efficiency Of Solar Water Heater Research Articles

A Numerical Study to Improve the Efficiency of Solar Collector used for water heating using Phase Change Material

Solar water heaters are an effective technology for harnessing renewable solar energy to provide hot water for households and businesses. However, their efficiency can be impacted by factors like intermittent sunshine, heat losses, and low radiation intensity. The aim of this study is to increase the efficiency of solar water heaters through the use of phase change materials (PCMs). PCMs have the ability to store latent heat during phase change, releasing it later when needed. This study uses numerical simulations to analyze the effect of integrating different PCMs into a flat plate solar collector design. The findings could then be validated experimentally and applied to improve the real-world performance of solar water heating systems. The PCMs are placed inside the collector to absorb heat during the day and release it after sunset to continue heating the water. The research seeks to determine the optimal PCM properties, structure, and placement within the collector to maximize heat storage and transfer. The efficiency and performance of the solar collector system with different PCM configurations have been compared to those of a conventional collector without PCM. The outcomes uncover that the use of suitable PCMs can significantly improve the efficiency and heat output of the solar collector, especially during periods of low radiation and after sunset. The optimal PCM configuration maintains higher water temperatures for longer, allowing solar water heating to continue into the evening. The results may provide valuable insights for using PCMs to boost the efficiency of solar thermal technologies

Efficiency enhancement of solar water heaters through innovative design

The purpose of this study paper is to examine the potential for increasing the efficiency of solar water heaters by using novel design ideas. A qualitative examination of previously published material is combined with the development of a computer-aided design (CAD) model of a solar water heater using the SolidWorks as part of this research project, which uses a mixed-methods approach. The qualitative study draws attention to the relevance of design factors, materials, and combinations in optimizing the collection and use of energy. The CAD model provides a graphical representation of the suggested design adjustments and demonstrates how the overall performance may be enhanced. The results highlight the significance of inter-disciplinary cooperation, consumer awareness, and legislative assistance in order to encourage the adoption of improved designs for solar water heaters. The paper comes to a close by providing some ideas for testing in the real world, continuing research, and incorporating inventive design into the process of promoting sustainable energy practices.

Studi Analitik Penambahan Reflektor Pelat Datar Sudut 60˚ pada Pemanas Air Tenaga Surya

The condition of electrical energy in Indonesia is increasing every year, one of which is used as a water heater. Various methods have been used to increase the efficiency of solar water heaters, including the use of flat plate reflectors. This research was carried out analytically to determine daily solar radiation intensity data on solar collectors with the addition of a 60˚ angle reflector. The results obtained in conditions without reflectors, the daily average solar radiation value produced by solar collectors is 1136 W/m2. Then for the condition of the reflector angle of 60˚, the daily average solar radiation value is recorded at 1386 W/m2. There is a difference of 250 W/m2 between the two conditions. The daily solar radiation intensity value is also calculated using the area method, the result is a daily solar radiation value of 2.542 kWh/m2 in conditions without the reflectors. Furthermore, at a reflector angle of 60˚, the resulting solar radiation value increases by 6% to 2.712 kWh/m2. The addition of a flat plate reflector at an angle of 60˚ is proven to increase the daily solar radiation intensity value that can be received by a solar water heater.

Spiral tube solar water heating computational analysis with concrete absorber: A CFD approach

Solar collectors with concrete absorber provide structural, aesthetic, and economic advantages over existing common technology. An inexpensive concrete solar collector is being considered to improve the efficiency of solar water heaters (SWH). This work mainly focuses on the analysis of the compact concrete absorbers for water heating purpose with the spiral tube arrangement using solar energy. Concrete absorbers that use straight tubes, while less performance, they are possibly more cost-effective than traditional flat-plate collectors. The flow analysis is to be evaluated ranged between 0.005 and 0.01 kg/s for various water flow rates on the inside of the spiral tube. Furthermore, it is anticipated how the temperature of the water at the exit and storage will behave in respect to solar radiation. A finite volume package ANSYS FLUENT 15 is used to investigate the characteristics of the flow over a SWH's duct. At the lowest mass flow rate, it is discovered that the typical concrete and sand absorber water temperatures are 70 °C and 75 °C, respectively.

The Various Designs of Storage Solar Collectors: A Review

The use of solar energy to heat water is the more critical application of solar energy. Researchers are trying to develop different methods to improve the efficiency of solar water heaters to meet the increasing demand for hot water due to global population growth. To reduce the cost and increase the efficiency of solar heaters, the solar collector and the storage tank are combined into one part, and this system is called solar storage collector. It can be defined as geometric shapes filled with water, painted black, and placed under the influence of sunlight to gain the largest amount of solar energy. This article presents the various designs of solar storage collector. This review showed that design variables and design shape significantly affect the efficiency of the solar heating system. Climate and operational factors also have a strong influence on the performance of solar heating. Furthermore, scientists and researchers have also used nanotechnology, solar cells, and mirrors to improve other stored solar collectors' performance. Finally, recently published articles indicate an increase in interest in improving the efficiency of solar storage collector by creating new designs that enhance the economic and practical viability.

Experimental thermal performance investigation of a direct absorption solar collector using hybrid nanofluid of gold nanoparticles with natural extract of Azadirachta Indica leaves

In the last decade, direct absorption solar collector has shown tremendous potential in improving the efficiency of solar water heaters by incorporating nanoparticles. Moreover, plasmonic nanoparticles laden nanofluids have shown high absorption in the visible region due to localized surface plasmon resonance (LSPR). However, these plasmonic nanoparticles are associated with high cost, complex preparation processes, and environmental degradation over prolonged use. To overcome such issues, a hybrid nanofluid based on gold nanoparticles in Azadirachta Indica leaves extract was prepared and tested in real outdoor conditions for the very first time. The absorbance curve of the prepared hybrid nanofluid showed broadband absorption from visible to near infrared spectrum. The maximum temperature gain of about 20 °C was observed with just 2 h of sun exposure and maximum photo–thermal efficiency reached nearly 62%, which is about 12% higher than base fluid i.e. water. Further, the prepared samples were found to be highly stable without any sign of sedimentation or agglomeration under repeated sun exposure for several hours. The study results show a new class of nanofluids that can be used for attaining high thermal conversion efficiency, which are more stable and eco-friendly for such novel solar thermal technologies.

A review on convective heat augmentation techniques in solar thermal collector using nanofluid

Solar water heating system is convincing technology to convert solar energy into thermal energy. According to the survey, approximately 42% of refined crude oil is used in industries and commercial applications for heating processes. Fossil fuel is the main energy source that is depleting continuously. Solar energy is an environment-friendly energy source, which can fulfill energy demand. Solar thermal collectors are most popular in domestic as well as industrial sectors for water heating due to their ease of operation and simple maintenance. Extensive work is going on to improve the thermal performance of solar thermal collectors using passive techniques. Passive techniques include the use of nanofluid, twisted tape, Phase Changing Materials. Active and passive techniques have a significant contribution to solar thermal collector thermal performance enhancement. This paper reviews the work carried out and current progress to enhance the thermal efficiency of solar water heaters using nanofluid. In addition to this, a detailed discussion and limitations of existing research have made from this discussion, research gaps are identified and possible future modifications are suggested.

Reduction in Heat Loss of Flat Plate Solar Water Heater by Modification in Material and Properties - A Review

Efficiency of solar water heater is in the range of 25-35% as out of 100% solar insolation, only 45% solar insolation can be used for heating purpose while 55% was getting waste due to heat loss by conduction, convection, transmittance, absorbance and radiation through absorber plate, collector glass, insulation material, piping, support structure etc. Heat losses from the panel are considerable (more than 50 components) due to prolonged withstanding of heat & cool cycles, physio-chemical reaction, lumpy insulation, gasket rupture, heat and cool cycles, poor water chemistry, ambient factors like wind/rain etc., pipe internal scales, acid and scales formation, radiation, conduction and convection losses through solar panel, gasket erosion due to condensate and UV light cracking etc.Heat gain can be achieved if temp. difference reduced (i.e. heat gain equals to product of heat removal factor ,transmissivity and absorptivity factor with removal of product of heat coefficient with difference of inlet temperature , ambient temperature therefore efficiency increased up to 69 % as per calculation improving the variables and control without sacrificing the performance, going towards ideal Carnot cycle. The passive system design is preferred (as there is no external energy input neither the pumps for increasing velocity). There is tremendous scope for improvement of efficiency by reduction of heat loss by use/substitution of non-thermal conducting materials, changing the material of solar water heater with better characteristics, changing orientation, geometry etc. There are about three main areas to be worked out i.e. solar collector panel, water tank and the inlet and outlet piping network along with water quality and taps, fittings etc. Major advantages of efficiency improvement are like reduction in electricity consumption for domestic water heating by 70%, reduction in conventional energy problems like global warming, pollution, acid rain etc.( as no fossil fuel required), cheap energy cost (i.e. less expensive than natural gas), easiness in source availability i.e. (average solar radiation by earth in energy equals to 722 W/m2 as for every 20 minutes the Sun produce enough energy to supply earth its need of entire year which can be converted to heat), energy security, benefit of accelerated depreciation/tax saving, meeting of renewable energy obligation, low operating and maintenance cost, possibility of direct conversion of solar energy(using PV cells ), inexhaustibility, ease for transport etc.

Investigation of Performance Parameters Affecting the Efficiency of Solar Water Heater: A Review

The need for installation of Solar Water heater is increasing in society because of several factors such as rapid urbanization, government interventions, low cost of installations, and environment-friendly application acting as a direct replacement to fossil fuels. During the past few years, the research and development associated with the technological enhancement of the utilization of solar energy have increased exponentially. However, there are various challenges involved in the selection of proper solar technology to provide a high-performance energy harvesting application for domestic water heating requirements. There is a wide literature available on various performance parameters required to develop an efficient Solar Water Heating System. This paper investigates a state-of-the-art review of the performance parameters affecting the efficiency of Solar Water Heaters by component-wise analysis of parameters divided broadly into the design, operational and external parameters. The technological advancements in solar water heaters are classified based on performance parameters and the paper summarizes the possibility of combining different performance parameters to achieve more efficient and cost-effective solar water heaters for the society as future scope of the review for researchers working in the similar domain.

Performance investigation of nanocomposite based solar water heater

Of late researchers are putting stress on the active utilisation of solar energy to promote the use of renewable energy. Solar water heating is considered as an environmental friendly technique to harness the solar energy for heating application. In this research, the effects of using Phase Change Materials (PCM) doped CuO nanocomposite as storage medium on the performance of a solar water heater have been experimentally investigated. By varying the wt% of nano CuO, the gap between the absorber plate and the glazing, the effect on the outlet temperature is examined. The maximum temperature of outlet water has been recorded as 60.1 °C using nano CuO-PCM composite over base PCM under similar conditions. As the mass fraction/wt% of nano CuO increases in PCM, the thermal conductivity, heat flow and thermal efficiency increases. It has been found that better results have been achieved while using 1.00 wt% CuO-PCM nanocomposite. The thermal conductivity of pure wax is found to be about 0.21 W/mK while 1.00 wt% PCM CuO- nanocomposite has thermal conductivity of 0.36 W/mK. It is noticed that there is an appreciable increment in the efficiency of solar water heater under the variation of three observed parameters i.e. time, temperature and solar intensity.

Comparison heat transfer between finn solar water heater pipe and normal solar water heater pipe using cfd

The development in the world of energy conversion has been progressing especially in the field of applying renewable energy resources related to the Sun. The application is not only in the world of industry but includes the smallest part or household. One application of solar energy resources is solar water heater. Solar water heater is a tool that utilizes heat from the collector to heat water flowing in tubes that are expected to increase the fluid exit temperature. In this study an increase in the efficiency of solar water heater is done by increasing the surface area of the pipe by adding fins on the side of the pipe which are expected to increase the temperature of the fluid out of the pipe that is plain or does not have fins. With the simulation method using CFD software obtained an increase in pipe exit temperature by 0.9%. this shows that in a part of a double-finned pipe, it does not significantly affect the increase in fluid exit temperature.

Optimization and Forecasting the Efficiency of Solar Water Heater by Mathematical Regression

The performance of the solar collector was experimentally studied under the different twist conditions namely helical twist, helical with left right twist and screw twist, L/D ratio (i.e., 0, 3 and 6) and time. Based on the standard relationship, efficiency of the collector was calculated for the different experimental combinations. Further, the significance of solar collector process parameters was identified by statistical analysis. Also the optimal solar collector process parameters to achieve the maximum the efficiency was identified and a mathematical regression was generated to forecast the efficiency of the solar collector.

A Review on Augmentation of Convective Heat Transfer Techniques in Solar Water Heating

Solar water heating system is an effective technology for converting solar energy into thermal energy. According to the ministry of petroleum and natural gas, approximately 42% of refined crude oil is used in industrial and commercial applications for process heating. Fossil fuel is the main energy source which is depleting continuously. Solar energy is environment friendly energy source, which can full fill energy demand. Solar water heaters are most popular in domestic as well as industrial sector due to its ease of operation and simple maintenance. Extensive work is going on to improve the convective heat transfer, thermal efficiency of solar water. Passive techniques like use of Nano fluid, twisted tape, Phase Changing Materials (PCM) are used to augment convective heat transfer. These techniques enhance thermal performance of solar water heating system significantly. This paper reviews the various techniques to enhance the thermal efficiency of solar water heaters. In addition to this, a detailed discussion and limitations of existing research have made. From this discussion research gaps are identified and possible modifications are suggested.

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

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.

Experimental and theoretical investigation on the effects of lower concentration CeO2/water nanofluid in flat-plate solar collector

Heat transfer characteristics of solar flat-plate collectors are improved by applying various nanofluids as the heat transfer media nowadays. In the present work, the theoretical and experimental analysis was performed for a flat-plate solar collector operating with water and CeO2/water nanofluid as the working fluids. The flat-plate solar water heater with 100 L per day capacity along with ladder-type heat exchanger having collector area of 2 m2 is fabricated for the experimental study. The average particle size and volume fraction of nanofluids were considered as 25 nm and 0.01%, respectively. The flow rate of water and nanofluid was varied from 1 to 3 lpm, and the efficiency was calculated as per ASHRAE standards. Due to the enhanced thermophysical properties of the nanofluid, it gives better performance and results showing that the maximum efficiency of solar water heater with CeO2/water nanofluid is 78.2%, which is 21.5% higher when compared with the water as base fluid. Also a correlation was developed for predicting the outlet temperature of a flat-plate collector. The maximum collector efficiency of nanofluid was obtained at the optimum mass flow rate of 2 lpm in experimental study. The developed mathematical model was reasonably matching the experimental results with the error of ± 7.5%.

Effect of Circular Fins on Latent Heat Storage to Enhance Solar Water Heater, an Experimental Study

In natural circulation solar water heating, the efficiency of energy storage and solar collector can be improved if the water tank is stratified. Employing Phase Change Material (PCM) in the top of the tank will improve the stratification of the energy storage tank. Current paper studies the use of circular fins around PCM geometry with high surface to volume ratio to improve the efficiency of solar water heater. Heating and cooling tests have been performed in a domestic water heater with flat plate collector under real working conditions. Eventually the temperature distribution along the height of the storage tank, charging energy efficiency, collector efficiency have been calculated and compared. Tests have been simulated in CFD software for validating results. Addition of circular fins around PCM produces up to 5% and 36.48% improvement in tank charging energy efficiency, collector efficiency respectively because of improved heat transfer between PCM and water.

Energy Efficiency and Cost Effectiveness of Solar Water Heaters

There are different opinions on the question of energy and economic efficiency of solar water heaters. Some researchers believe in high effectiveness of solar water heater application while others questions their cost effectiveness. In this arti¬cle detailed investigations have been accomplished to discover energy and economic real efficien¬cy of different types of solar water heaters on the base of suggested procedure for their real payback periods determination. It’s proved that flat type solar water heater has much longer payback than newly suggested cylindrical shell and tube type solar water heater.

A Study on Thermal Performance of a Novel All-Glass Evacuated Tube Solar Collector Manifold Header with an Inserted Tube

A novel all-glass evacuated tube collector manifold header with an inserted tube is proposed in this paper which makes water in all-glass evacuated solar collector tube be forced circulated to improve the performance of solar collector. And a dynamic numerical model was presented for the novel all-glass evacuated tube collector manifold header water heater system. Also, a test rig was built for model validation and comparison with traditional all-glass evacuated tube collector. The experiment results show that the efficiency of solar water heater with a novel collector manifold header is higher than traditional all-glass evacuated tube collector by about 5% and the heat transfer model of water heater system is valid. Based on the model, the relationship between the average temperature of water tank and inserted tube diameter (water mass flow) has been studied. The results show that the optimized diameter of inserted tube is 32 mm for the inner glass with the diameter of 47 mm and the water flow mass should be less than 1.6 Kg/s.

Determination of the Performance Characteristics of a Modified Solar Water Heating System

Heated water is very essential for domestic, agricultural, commercial as well as industrial operations. Obtaining hot water usually comes with a cost. Though conventional water heating systems exist, however, the operational cost and environmental impact of this method is contributing seriously to the already worsened energy situation in Nigeria. Solar water heating system (SWHS) is a practical application to replace the conventional electrical water heater. The low efficiency of solar water heaters has been the main reason why many people still prefer the conventional methods. To improve on the performance characteristics of the existing solar water heater, a modified version was developed by re-shaping the solar collector and making it adjustable so that it could attract maximum solar radiation. The pipe was replaced with another pipe of smaller diameter to allow for more heating surface area using the same collector frame. The tank and the sides of the collector frame were lagged with a special polysterine material to reduce heat loss due to radiation and a unidirectional control valve was introduced to the tank so that the already heated water that can be preserved in the tank. Tests were carried out on the existing as well as the modified heaters. The results obtained show a significant improvement on the performance of the SWHS. The inlet average temperature increased form 24.64 oC to 35.14oC while the outlet temperature increased from 51.53oC to 60.73oC which corresponds to an improvement in the performance of the system’s inlet water temperature of 15.65% and outlet water temperature of 15.14%.

COMPARATIVE EXPERIMENTAL STUDY OF SIMPLE ABSORBER PLATE WITH ABSORBER PLATE HAVING CONCAVITIES

Solar water heater is one of the most widely used solar applications. Lot of study has been carried out on the enhancement of the thermal efficiency of solar water heater .In this experimental work the performance of conventional absorber plate is compared with the newly proposed absorber plate having concavities. The results shows that there is an improvement in the heat transfer rate. The heat transfer rate is increased by 5.12%. It shows that the increase in outlet temperature due to the provision of concavities which increase the diffusion area for radiation reducing the reflection losses.