Having a reliable, low-cost, and always available energy production system has announced the energy storage systems as an important candidate. There are different methods to store renewable energies, which the storage of latent heat energy is more important one because of its ability to generate high energy storage density at constant temperature (PHASE CHANGE PHASE). Organic or inorganic compounds that are capable of absorbing and storing large amounts of heat energy are called PHASE-CHANGE MATERIALs. Due to the high efficiency and high capicity of PHASE-CHANGE MATERIALs in energy storage systems, the use of these MATERIALs in recent years has attracted many developed countries. The purpose of this paper is to review the various types of PHASE-CHANGE MATERIALs, the application systems and the other researches on these materia ls.

Domestic refrigerators have become an essential part of modern life.Since these devices are connected to the power grid and operate continuously throughout the day and year, they consume a lot of energy.Experimental studies show that adding PHASE CHANGE MATERIALs in refrigerators in different places improves the energy efficiency of these appliances.In this study, the effect of adding a PHASE CHANGE MATERIAL(PCM)box on the thermal performance and electricity consumption of a single-door refrigerator/freezer is studied.The box of PHASE CHANGE MATERIAL is attached to the bottom surface of the evaporator with different MATERIALs.Water with a melting temperature of zero degrees Celsius has been used as a PHASE CHANGE MATERIAL.To study the effect of increasing the thermal conductivity of water, fins with the same MATERIAL(copper, aluminum and steel)as PCM box are placed in the box to evaluate their effect on temperature distribution and power consumption.The results show that the presence of the water box in contact with the bottom surface of the evaporator helps to reduce the temperature of the cabin due to the potential of water as a PHASE CHANGE MATERIAL in absorbing and releasing cooling energy.Also, the results show that copper is more suitable for water storage because of its higher thermal conductivity and it helps to more evenly distribute the temperature.Furthermore, using a fin inside the water chamber, in addition to limiting the temperature range of the cabin, on average causes a further reduction in energy consumption by 1 to 4% compared to the case without a fin.

Due to their high latent heat, PHASE CHANGE MATERIALs have can store and release a large amount of thermal energy during PHASE CHANGE. Meanwhile, PHASE CHANGE MATERIAL nanoemulsions have received much attention due to their suitable heat transfer properties and high heat storage capacity. In addition to the sensible heat capacity of the carrier fluid, these MATERIALs also have the ability to store thermal energy by using the latent heat capacity of PHASE CHANGE MATERIALs in the form of a dispersed PHASE. Also, due to the large surface to volume ratio of the dispersed PHASE on very small scales, heat transfer accelerates in this nanoemulsion system. In the present work, a comprehensive study on the formulation, thermophysical and rheological properties of nanoemulsion PHASE CHANGE MATERIALs is presented, in order to provide an insight into the advantages and challenges of using these MATERIALs. In addition to the experimental investigations on emulsions stability during storage time, and under thermal cycles and shear mechanical stresses have also been discussed. The effect of droplet size, stabilizer type and dispersed PHASE concentration on supercooling and other rheological and thermophysical properties of nanoemulsions such as thermal conductivity and density have also been investigated in order to determine the cooling-heating rate and volume required for energy storage, respectively. Finally, the potential of PHASE CHANGE MATERIAL nanoemulsions for the effective management of thermal energy and promoting the methods of using renewable energy in different fields has been reviewed.

The purpose of this research is to design energy storage tanks using PHASE CHANGE MATERIAL (PCM) in air conditioning system that PCM is part of the heat pump system and is connected directly to the air conditioner. From simulation and modeling methods through coding in software, parametric analysis, as well as introduction and suggestions for use a suitable PCM to store and reduce energy consumption in the building and check the performance of the heat exCHANGEr in the latent heat storage using PHASE CHANGE MATERIALs is effective, are discussed. In this paper, first the thermal and refrigeration loads calculated using Carrier software and in the following, the cooling and heating process is simulated. Finally, from the PHASE CHANGE MATERIAL in different modes used for energy storage in cooling and heating processes and is simulated in EES software. After modeling analysis with a minimum temperature of-5° C and maximum temperature 38° C considered and in different situations, the most suitable option for PCM tank mode in the heating process at the inlet temperature 35° C using 20 pipes in each row and PCM tank mode in the cooling process at the inlet temperature 10° C and selected using 22 tubes in each row.

In the light of importance of sustainabile development, global warming as well as mortality of Fossil fuel correspondingly using of solar energy be more and more important. Photovoltaiv panel is an application of solar energy resource. A weakness of Photovoltaic panel is efficiency reduction caused by temperature increase. The efficiency of photovoltaic panel decreases by approximately 0. 5% per Kelvin. There are different methods to PV thermal regulation, which the use of PHASE CHANGE MATERIAL is more important one. Organic or inorganic compounds that are capable of absorbing and storing large amounts of heat energy are called PHASE-CHANGE MATERIALs. Due to the high efficiency and high capicity of PHASE-CHANGE MATERIALs in energy storage systems, the use of these MATERIALs in recent years has attracted many developed countries. Accordingly, this paper reviewd studies about using PCMs for PV thermal regulation. Considering to the considerable enhancement of the PV performance via application the PCM, the PCMs can be a appropriate solution for the PV performance enhancement.

Among all kinds of renewable energies, the solar energy has the greatest application compared to the other types. However, the biggest shortage of solar collectors is their low effectiveness at night or in the cloudy weather. The latent heat storage of PHASE CHANGE MATERIALs (PCMs) can be utilized as a solution for the above-mentioned problem. However most PCMs have low thermal conductivities. In this research aluminum oxide (Al2O3) and copper (Cu) nanoparticles were used to enhance the thermal properties of Paraffin wax as a PCM. The morphology of the nanocomposites was studied by Field Emission Scanning Electron Microscopy. The experiments were performed in a factorial arrangement in a completely randomized design with three main factors including weight percentage (three levels), type (two levels), and size of the nanoparticles (three levels) and pure Paraffin wax used as a control sample. Thermal conductivity of nanocomposites was measured at a temperature range for each sample and in the solid PHASE. The highest and lowest values of thermal conductivity coefficients compared to control sample have increased 442% and 122%, respectively. Analysis of variance results showed that the size, type and concentration of nanoparticles affected thermal conductivity of nanocomposites significantly (p<0. 01). In different size of nanoparticles, thermal conductivity coefficient of nanocomposites has increased with increasing of the nanoparticle concentration. Also, the highest thermal conductivity coefficient of nanocomposites was obtained at the smallest size of the nanoparticles. The highest thermal conductivity coefficients of nanocomposites were achieved by addition of Cu nanoparticles at the weight percentage of 6% and sizes of 30 and 70 nm to Paraffin wax.

The power supply, as the main supplier of electrical energy, is used in many electronic devices and circuits. This research has experimentally investigated the thermal management of a computer power supply which uses PHASE CHANGE MATERIALs to increase the lifetime, to improve the performance, and to reduce energy consumption. Two heat sinks have been designed and fabricated in two types of plate-fin and pin-fin. The experiments were carried out in the thermal fluxes range of 2. 1 – 4. 8 and in the constant volume fraction of the PHASE CHANGE MATERIAL. The results show that the maximum reduction in steady temperature is 10. 4 and 8. 6, in the pin-fin and plate-fin heat sink respectively, . Also, the results indicate a better performance of the plate-fin heat sink in comparison with the pin-fin in the process of reducing temperature and cost.

The hot climate in Basra city requires many research to find a solution to reduce heat. Usually the thermal pump needs an external energy to ensure its continued operation. The objective of the study is the possibility of building a heat pump using renewable energy. The present work addresses a renewable energy heat bump by using paraffin wax during the daytime. The experimental and the CFD model of the solar collector and Thermal Energy Storage (TES) system based on PHASE CHANGE MATERIALs (PCM) as a renewable heat pump system are presented. The system consists of three main parts: The solar collector, paraffin wax cavity, and cooling room. An experimental rig is constructed to conduct a practical analysis by measuring the intensity of solar radiation at different hours of the daytime. Temperatures distribution are measured with 24 type K thermocouples at different sites for the system. A numerical investigation has carried out to predict flow and heat transfer for the solar heat pump. Free convection of turbulent flow with 2-D unsteady state incompressible flow is examined. The numerical work is divided into two parts: The first part presents the development of numerical models of the heating collector room while the second is the numerical model of paraffin wax room. ANSYS FLUENT code 16 is applied to solve Navier Stock, energy, and k-Ɛ model equations by using finite volume method. The calculations of the velocity, temperatures distribution, and the Nusselt number values with different Rayleigh number for air at both heat collector room and paraffin wax room at different daytime are reported. The results of the present work guarantee future development of this technology for the food or agriculture industry. Maximum cooling temperature of the hot air is reached more than 20oC. It is found that a PCM leads to maximum energy savings and greater peak load at high solar intensity value. The practical results are also compared with numerical results, and good agreement is obtained.

The photovoltaic/thermal system is capable of generating both heat and electricity simultaneously. The purpose of using spectral filters is to make full use of the solar radiation spectrum and thermal separation of photovoltaic and thermal units. The purpose of this paper was to investigate a new hybrid spectral filter consisting of PHASE CHANGE MATERIAL and nanofluid to achieve a filter close to the ideal spectral filter. In this regard, the photovoltaic/thermal system with a combined nanofluid-PHASE CHANGE MATERIAL spectral filter was simulated using energy balance equations in MATLAB software and its performance was compared with two conventional and nanofluid-based spectral splitting photovoltaic/thermal systems from energy and exergy viewpoints. Also, the optical properties of nanofluid and PHASE CHANGE MATERIAL were simulated and the models were validated with the experimental data available in the literature. The results showed that by using a combined filter the photovoltaic temperature can be reduced by up to 50% and the output fluid temperature can be increased by twice. The exergy efficiency of the system with the combined filter was about 14% and 22% higher than conventional and nanofluid-based spectral splitting photovoltaic/thermal systems, respectively. The system also achieved the highest exergy efficiency at concentration ratios greater than 15.