of FPSC are shown in Fig. 1 and 2, respectively. The collector specifications are given in Table 1. When solar radiation of halogen lamps passes through a glass cover and hitting the blackened absorber surface of high absorptive, a large part solar energy is absorbed by the plate heat up, changing solar energy into heat energy. The heat is transferred to the transport medium in the fluid tubes to be carried away for storage or use. The fluid circulates in a closed system with using the water pump. Experimental procedure: The solar collectorperformance has experimentally investigated in Karbala, Iraq latitude 32.6°N and longitude 44.02°E data is recorded under transient conditions. The solar collector is tilted to South facing with 12° 22, 32, 42, 52 in Summer, the beam component is more than the diffuse component and thus the the main contribution comes from the beam component that leading to the optimum tilt is less usually latitude -10° (Gunerhan and Hepbasli, 2007) (Table 2).
Since values of UL and HR are usually low compared to H, the efficiency factor becomes a strong function of heat transfer coefficient H. Therefore any change in flow rate significantly changes the heat transfer coefficient and hence the efficiency. It can be recalled from the earlier results that any change in parameter influences the efficiency mainly through the change in flow. Therefore it is important to consider flow rate as an independent parameter in determining the performance characteristics. This can be verified from the fact that previous characteristic curves drawn for various configurations do not match for any other operating temperature difference on insolation for a given (ΔTF/IR) value. Thus the characteristic curves are to be obtained for constant flow rates by varying the (ΔTF/IR). Such curves for various flow rates in the commercialized configurations are given in Graph 3.
Figure 4.a) shows the evolution of temperatures and sunshine and 4.b) the evolution of the pressure as a function of the operating time of the system. The sunshine and ambient temperature curves are obtained from the experimental values recorded during the day of 11/04/2016 on the IRSAT solar fridge. These values have been implemented in the MATLAB code. Simulations of the adsorbed mass of refrigerant and the pressure of the reaction medium are made by fixing the condenser and evaporator temperatures respectively at Tc = 30 ° C and Te = 5 ° C. At sunrise, the temperature of the adsorber is almost equal to that of the ambient. As the time goes on, the adsorber overheats proportionally to solar radiation. This heating continues until the solar flux reaches its maximum value. For the day of 11/04/2016 this maximum value is 1120 W / m 2 at the turn of 1.00 PM. At the same time, the recorded outdoor temperature reached 36° C. The temperature of the reaction medium reached a peak of 94° C while that of the glass is 68.4° C. Figure 5 illustrates these phenomena well. Indeed, the more the day is sunny, the higher the temperature inside the collector is improved. Just after these peaks, the solar flux decreases and the cooling of the adsorber begins and continues until the temperature is equal to the ambient temperature. The temperature threshold of the adsorbent bed is the regeneration temperature (Tg), the temperature from which the adsorbate vapor desorption is finished. Numerical studies carried out by C. Wassila (2008) and K. Amadou et al (2016) on solar adsorption refrigeration systems operating with several adsorbent / adsorbate pairs, have shown that the highest Tg values make it possible to improve system performance. For the zeolite / water pair, the coefficient of thermal performance is between 0.4 and 0.47 when Tg is between 87 ° C and 107 ° C with Ta = 30 ° C, Tc = 30° C and Te = 5° C (2008). Figure 6 also shows the time variation curves of the adsorbent bed temperature for different days of operation. It is noted that these curves have the same pace except that the temperature peaks vary from one day to another and are not reached at the same time of the day. This can be explained by the difference in solar flux received on the collectorsurface.
Many authors [4, 5] have concentrated on the development of effective design methods for solar collectors. For their analysis the cross sectional area of the absorber plate has been constant. However, the collector receives energy from the sun that is absorbed by the plate and is then transferred to the fluid. On this basis, energy transferred increases in the direction of flow energy in a plate. It is well known fact that for effective design, the profile shape of the absorber plate increases the collectorperformance.
The solar collector is one of the devices which can absorb and convert energy form the sun to a usable or storable energy in many applications such as drying the agricultural products, marine products as well as heating of the building. There are varieties of designs for solar thermal collector application, like parabolic trough, solar air collector (flat plate collector) widely used in the SCPP. When solar radiation reaches the surface of the transparent cover of a solar collector (canopy) some of the radiation is reflected back while high percentage of the radiation pass through the Perspex to the ground (black pebbles) that absorbed and converts the solar energy to thermal energy in the collector. The collector of a SCPP has been majorly considered as one component of the system that can be improved to enhance the performance of a SCPP. Al- Azawie et al.  considered different types of ground materials and presented the preliminary results of an experimental and numerical study on enhancing SCPP collectorperformance. They discussed and compared the results of the ground materials and concluded that the ceramic and the stone performed better than the other types of materials.
In solar water heating system the solar collector is the heart of the system, in recent years a lot of studies were carried out to improve the collector performances which are mainly by changing the collector size, structure, shape, material, reducing the great loss or by improving the absorptivity of the coating. In solar adverse region we cannot utilize water as working fluid in solar water heating system. This is due to the fact that water based collector are susceptible to freezing. The selection of a working fluid for the solar water heating system plays an important role for the development of an environment friendly, efficient, low cost and can also function in low surrounding temperature. In addition, from the viewpoint of protecting the ozone layer and preventing global warming, there is now strong demand for technology based on ecologically safe ‘natural’ working fluids.
The evacuated tube solar collector with heat pipe is modelled. The heat losses in the outer glass and inner glass and at the evaporation and condensation segment are calculated using the thermal resistances. The properties of the heat pipe is given in table 2. The proposed model is shown in fig.1. The collector efficiency is calculated numerically and regression analysis is perform to fit and predict the best model statistically by using the computer program. EXCEL and MATLAB is used to perform the calculations. The Higher the R value lower the RMSE (Root Mean Square Error) value to determine the goodness of fit.The mathematical model for ETSC-HP is developed by forming the thermal resistance network and the heat loss and useful heat is calculated by the thermal resistances. The heat entering the tube is through convection and radiation and transfer of heat through the convection principle. All the convection and radiation losses are calculated and useful heat gained by the collector is known for this the mathematical model is developed.
The solar collector is considered as the heart of a solar thermal system. The main function of the solar thermal collector is to absorb solar radiation and convert it into heat to a fluid with the maximum possible efficiency . The main component of the collector is absorber which generates heat by absorption of the solar radiation . Also, the absorber must be designed with low emission capacity in the heat radiation spectrum and high absorption capacity in the solar spectrum . The absorber contains pipes or sheets filled up with a heat transfer medium, and the medium flows to the collector to absorb the heat from solar radiation and return back to the hot water store. The heat exchanger is occasionally used to draw heat from the water-glycol mixture that is circulated in a closed circuit . Moreover, there is limited heat loss to the ambient in the collector by using thermal insulation underneath the absorber and transparent cover in front .
An advanced thermal solar driven air conditioning system for hot climate is described and a steady state thermodynamic model is used to predict its performance by using weather data for Doha (Qatar). The proposed system combined both Organic Rankine Cycle (ORC) and conventional mechanical Vapour Compression Cycle (VCC) whereby the expender (Turbine) is coupled to the compressor. Both cycles operate with ammonia refrigerant. For the same collector surface area (20 m 2 ), the corresponding average daily cooling production is
This work presents a detailed analysis of an improved Integrated Collector Storage Solar Water Heater (ICSSWH). This type of device is well suited for rural areas of Morocco because of its low cost, simplicity and compact structure. The innovation targeted in this system lies in the integration of a latent storage system by using a layer of phase change materials (PCM) in its lower part. Indeed, this integration is likely to increase the thermal energy delivered to the user during the night. The overall performance of the system depends on external climate data, type of PCM used and its mass, and flow rate of water. N-eicosane is considered as PCM in this application while hourly weather data corresponding to the city ER-RACHIDIA is used for the analysis. A detailed 2-D transient simulation has been established to optimize the system performance by studying the effect of different design variables and operating conditions. A deep analysis was also made to understand the PCM melting and solidification processes for a better exploitation of this storage technique. Optimized results are obtained when a mass flow rate of 0.0015 kg/s is used with a PCM thickness of 0.01 m and a set temperature of 313 K. Keywords:
asphalt slabs. The copper tubes were embedded in the asphalt slabs for the purpose of water circulation and the thermal sensors were also embedded in different depths for temperature measurement during slab preparation. A laboratory simulation test was performed to heat up the asphalt slabs. The thermal energy stored in the slabs was collected by the circulating water. The effect of flow rate, the time for starting collection and the initial temperature distribution of the slabs on the process of heat collection were evaluated. The results shows asphalt solar pavement can be cooled by the solar collector thus is good for reducing heat islands in a city.
One among the major objectives of the study is to investigate for the improvement of the system and its correlation with the physical arrangement of the solar collector and the biomass-gasifier-boiler connected in parallel to the thermal energy storage tank. Simple sensible thermal storage type is adopted in the study due to its simplicity and established principles compared with the other two types which are phase change and chemical reaction type of thermal storage materials. Given that water or any kind of working fluid has a uniform temperature, fully mixed or
possession, humanity, identity, eccentric, preservation, order, status, knowledge, memory were words that continually presented themselves whenever I discussed the work. I began making lists of these words and putting together what ended up being obscure lists of possibilities, but in the end I went back to the root of what I was displaying. Although using the word ‘collector’ may have not been the most creative title, it seemed to be the most logical. It would instantly engage the viewer to what they were about to see, no matter if they were looking at the sign outside the gallery, a poster or postcard. I decided to use a few of the ‘key words’ off of my list of reoccurring themes as a subheading as a means of explaining my intent, allowing the viewer to begin to digest my concepts. In the end, I chose the words, ‘collection,’ ‘possession,’ and ‘persona’ which I felt began to pinpoint a few of my basic interests in making this work.
ABSTRACT: The energy is always a need to continue the life cycle with low cost and high efficiencies at the end of the day output. And engineering is always in the hunt of the new and best technology to furnish the vast and clean output which should be obviously friendly to the nature. So, it is intended to build a machine which can give more efficient and clean energy with low cost, powerful and also friendly to the nature, for that it is simple to switch the solar energy system. As everyone knows that the solar energy is enormous and abandon in nature and some thousand watts of heat energy is transmitted to our earth from the sun in the form of light every day. The PTSC (Parabolic Trough Solar Collector) technology is very useful as it is used for approximately all solar energy applications such as steam and power generation, water heating, air heating etc. The prototype of the parabolic trough concentrating collector is manufactured using the available materials (plywood, Reflective Aluminium sheet, storage tanks, and copper tube) and equipment in the workshop. An experimental setup has been developed to investigate the performance of the solar parabolic trough collector. Measurements of total direct radiation on the plane of the collector, ambient temperature, wind speed, water flow rate, and inlet and outlet temperatures of the water inside the absorber tube are collected and employed in studying the performance of the parabolic trough.
The objective of gift study is to perform CFD simulation and fabricate the reflector. The results obtained by CFD simulation are validated with experimental results. The experimental conditions ‘taken for solar air collector, a similar has been used for CFD simulation. The general aim of work is grasp the flow behavior and temperature distribution of air within the reflector and compares the outlet ‘temperature of air with experimental results.
more than open CPC. Overall efficiency of closed CPC is 10% more than open CPC system. It was also observed that glass cover doesn’t allow soil and dust particle to get deposited over reflector and absorber tube which enhances the overall performance of CPC as well as reduces the cleaning problems. This system can be commercialized by varying design specifications as per requirement to produce hot water at desired temperature to satisfy industrial and domestic demands.
number of adsorbers to be added to a machine. This latter is considered for consuming an energy equivalent to that received by the adsorber-collector. These additional adsorbers use a heat transfer fluid, coming from the adsorber-collector, instead of direct heating by solar radiation. An application example is presented using experimental results obtained from the literature. It has shown that the number of the additional adsorbers can reach three adsorbers.
when the solar direct radiation exceeded a certain value, the curves(I-V) almost became a straight line and the output performances decreased due to the high series resistance leading to the high power loss. For the triple junction GaAs solar cell array, its performance was always excellent. Kuznetsov et. al2011,demonstrate that the application of transition metal-oxide nanorods to the surface of silicon solar panels can enhance the power output of the panels. Koussa et al. 2011, investigate the effect of using different sun tracking mechanisms on the flat plate photovoltaic system performances and the main parameters affecting the amount of their electrical energy output as well as those affecting their gains compared to the traditional fixed photovoltaic systems. It was found that for a completely clear day, the highest obtained gains are those related to the two-axis sun tracker systems, which decrease gradually from the inclined to the vertical rotating axis when the same optimum slope is applied and from the seasonal to the yearly optimum slope if the same rotating axis is considered. On the other hand, for the partially clear days, the gain amounts are mainly dependant on the clearness index and on the seasonal variation of day length values. For a completely cloudy day, the results show that all considered systems produced closely the same electrical energy and the horizontal position of the photovoltaic panel presented the best performance. Agrawal and Tiwari 2011, evaluate the theoretical performance of a glazed hybrid micro-channel solar cell thermal (MCSCT) tile. Experiment has been performed in indoor condition and it has been observed that there is good agreement between theoretical and experimental values with correlation coefficient and root
Abstract: Solar flat plate collectors are devices adapted excite solar thermal energy and use it for heating applications like water heating, house heating and totally different industrial applications. Flat plate collectors [FPCs] are normal for low and medium heating applications. Therefore, statistical and experimental studies were conducted on site in order to improve the thermal efficiency of FPCs.Coolant oil is utilized as fluids are the foremost effective ways in which to improve heat transfer. Comparison of varied heat transfer improvement methods, that cause choosing the foremost effective chance among them. The results of mode parameters just like the thickness and coating of the glass cowl, the thickness and material of the sorbent material plate, the air gap between the sorbent material plate and so the glass cowl, and so the space between risers and so the insulation materials are thought of to spice up the performance of FPCs. The influences of the atmosphere conditions, mass flow, angle and constant on the performance of the collector with clear insulating materials were analyzed.