An Improvement in the Solar Water Heating Systems by Thermal Storage Using Phase Change Materials

Solar Energy ◽  
2006 ◽  
Author(s):  
D. Vikram ◽  
S. Kaushik ◽  
V. Prashanth ◽  
N. Nallusamy
Keyword(s):  
Phase Change ◽  
Solar Collector ◽  
Storage Tank ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Control Device ◽  
Hot Water ◽  
Water Heater ◽  
Storage Unit ◽  
Solar Water

The present work has been undertaken to study the feasibility of storing solar energy using phase change materials (like paraffin) and utilizing this energy to heat water for domestic purposes during nighttime. This ensures that hot water is available through out the day. The system consists of two simultaneously functioning heat-absorbing units. One of them is a solar water heater and the other a heat storage unit consisting of Phase Change Material (PCM). The water heater functions normally and supplies hot water during the day. The storage unit stores the heat in PCMs during the day and supplies hot water during the night. The storage unit utilizes small cylinders made of aluminium, filled with paraffin wax as the heat storage medium and integrated with a Solar Collector to absorb solar heat. At the start of the day the storage unit is filled with water completely. This water is made to circulate between the solar collector and the PCM cylinders. The water in the storage tank receives heat form the solar collector and transfers it to the PCM. The PCM undergoes a phase change by absorbing latent heat, excess heat being stored as sensible heat. The water supply in the night is routed to the storage unit using a suitable control device. The heat is recovered from the unit by passing water at room temp through it. As water is drawn from the overhead tank, fresh water enters the unit disturbing the thermal equilibrium, causing flow of heat from PCM to the water. The temperature of the heated water (outlet) is varied by changing the flow rate, which is measured by a flow meter. The storage tank is completely insulated to prevent loss of heat. The performance of the present setup is compared with that of a system using same PCM encapsulated in High Density PolyEthylene (HDPE) spherical shells.

scholarly journals Design, Developing and Construction of an Educational Solar Water Heating System with Phase Change

2015 ◽  
Vol 10 (1) ◽  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Solar Collector ◽  
Heat Storage ◽  
Heating System ◽  
Storage Unit ◽  
Solar Water Heating ◽  
Solar Water ◽  
Solar Water Heating System ◽  
Change Material

An educational solar water heater with phase change material (PCM) was designed, developed, and constructed for instructional and demonstrative purposes. This interactive solar water heating system experimental apparatus is capable of demonstrating thermal energy storage and heat transfer concepts and principles. The system consists of two simultaneously functioning heat absorbing units. The first is a flat plate solar collector and the other is a heat storage unit consisting of phase change material (paraffin wax). The heat storage unit utilizes small aluminium cylinders (heat exchangers) filled with paraffin wax as the heat storage medium. Water pump is used to circulate the water between the solar collector and the storage unit where the PCM is located. Results indicate that the PCM stored energy, as latent heat, that was absorbed by the solar collector and released to heat the water in the storage tank when half of the hot water was replaced with cold water. Moreover, tests indicated that latent heat storage is more effective than sensible.

Evacuated Tube Solar Collectors Integrated With Phase Change Materials and Silicone Oil

2017 ◽  
Author(s):  
Alexios Papadimitratos ◽  
Sarvenaz Sobhansarbandi ◽  
Vladimir Pozdin ◽  
Anvar Zakhidov ◽  
Fatemeh Hassanipour
Keyword(s):  
Phase Change ◽  
Solar Collector ◽  
Phase Change Materials ◽  
Silicone Oil ◽  
Solar Water Heater ◽  
Water Heater ◽  
Solar Water ◽  
Water Heaters ◽  
Evacuated Tubes ◽  
Solar Water Heaters

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.

scholarly journals Experimental and Modeling Dynamic Study of the Indirect Solar Water Heater: Application to Rabat Morocco

2018 ◽  
Vol 7 (1) ◽  
pp. 86
Author(s):  
Ouhammou Badr ◽  
Azeddine Frimane ◽  
Aggour Mohammed ◽  
Brahim Daouchi ◽  
Abdellah Bah ◽  
...  
Keyword(s):  
Storage Tank ◽  
Weather Conditions ◽  
Hot Water ◽  
Experimental Setup ◽  
Solar Water Heater ◽  
Water Heater ◽  
Forced Circulation ◽  
Solar Water ◽  
Experimental Values ◽  
Temperature Output

The Indirect Solar Water Heater System (SWHS) with Forced Circulation is modeled by proposing a theoretical dynamic multi-node model. The SWHS, which works with a 1,91 m<sup>2</sup> PFC and 300 L storage tank, and it is equipped with available forced circulation scale system fitted with an automated sub-system that controlled hot water, is what the experimental setup consisted of. The system, which 100% heated water by only using solar energy. The experimental weather conditions are measured every one minute. The experiments validation steps were performed for two periods, the first one concern the cloudy days in December, the second for the sunny days in May; the average deviations between the predicted and the experimental values is 2 %, 5 % for the water temperature output and for the useful energy  are 4 %, 9 % respectively for the both typical days, which is very satisfied. The thermal efficiency was determined experimentally and theoretically and shown to agree well with the EN12975 standard for the flow rate between 0,02 kg/s and 0,2kg/s.

scholarly journals A small parabolic trough collector as a solar water heater: an experimental study in Ouargla region, Algeria

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Djamel Benmenine ◽  
Mokhtar Ghodbane
Keyword(s):  
Thermal Performance ◽  
Solar Collector ◽  
Hot Water ◽  
Solar Water Heater ◽  
Parabolic Trough ◽  
Water Heater ◽  
Parabolic Trough Collector ◽  
Solar Water ◽  
Knowing That ◽  
Average Consumption

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

Sign in / Sign up

Export Citation Format

Share Document