Transient modelling of multi-pass solar hot air dryer as a physical system is presented in this present work. SIMSCAPE/SIMULINK tool was utilized for the theoretical study of hot air passing through transparent flat plates and anodized aluminium as solarthermalcollector. Pebble bed made of granite was obtained locally to sever as the sensible heat reservoir. The thermal energy balance was resolved using lumped component technique. The parameters, variables and operating conditions of materials that constitute the thermal system forms the modelling input with available weather data collected in the Solar Research Site, Universiti Teknologi PETRONAS (4.385693 o N and 100.979203 o E). The model revealed improved on the multi-pass system performance efficiency by 12.4% and 10.1% when compared to the reported single pass and double pass solar air heaters. Closed loop control mechanism was imposed to achieve a steady heat flow 471.2 Js -1 to the drying compartment. A temperature gradient of 31.21 K was predicted which is suitable for the drying operation of many agricultural products. The theoretical result was in agreement with output obtained from the humidity controlled drying test system in the Solar Energy Laboratory, Universiti Kebangsaan Malaysia. However, there was need to improve the boundary condition accuracy and flexibility to accept various materials for system boundary.
A variety of technologies exist to capture solar radiation, but of particular interest of authors is evacuated tube technology. Numerous authors have noted that ETSCs have much greater efficiencies than the common FPC, especially at low temperature and isolation. For instance, Ayompe et al. Conducted a field study to compare the performance of an FPC and a heat pipe ETSC for domestic water heating system. With similar environmental conditions, the collector efficiencies were found to be 46.1% and 60.7% and the system efficiencies were found to be 37.9% and 50.3% for FPC and heat pipe ETSC, respectively. An ETC is made of parallel evacuated glass pipes. Each evacuated pipe consists of two tubes, one is inner and the other is outer tube. The inner tube is coated with selective coating while the outer tube is transparent. Light rays pass through the transparent outer tube and are absorbed by the inner tube. Both the inner and outer tubes have minimal reflection properties. The inner tube gets heated while the sunlight passes through the outer tube and to keep the heat inside the inner tube, a vacuum is created which allows the solar radiation to go through but does not allow the heat to transfer. In order to create the vacuum, the two tubes are fused together on top and the existing air is pumped out. Thus the heat stays inside the inner pipe sand collects solar radiation efficiently. Therefore, an ETSC is the most efficient solarthermalcollector. An ETSC, unlike an FPC, can work under any weather conditions while it provides acceptable heat efficiency.
To do this, a mathematical model based on the solarcollectorthermal balance method is studied. The results of the numerical simulations were used to eva- luate the temperature profiles of each solarcollector layer (glass, absorber, fluid and insulating plate). In order to validate the theoretical results, numerical re- sults obtained with Comsol code are used to compare the evolution of the ther- mo-physical parameters of the fluid in the solarcollector. The comparative analysis of the theoretical and experimental results of the double-pass solarthermalcollector has enabled the model to be validated.
Abstract: Almost all single-family detached house in Canada consume huge electricity for space heating and domestic hot water (DHW) purposes. There are many possibilities to design an energy- efficient house. A solar water heating system can be used for domestic water and space heating. Water temperature can be kept constant always by connecting a heat pump or oil burner because solar energy is intermittent. Proper and optimized solar photovoltaic and collector design, tank design, heat pump selection, house insulation, total demand calculation in each section are essential. Energy- Efficient house design has been proposed with water heating and space heating system and compared with the existing system, solar PV based systems, and solarcollector based system. The tracking and non-tracking based solarthermalcollector based and the solar photovoltaic based system has been compared in this paper and investigate the suitable one for practically applicable and acceptable by the people. Simulation has been done by using the PolySun software. It found that by implementing the proposed PV based system with tracking is highly suitable considering lower cost, high output power, flexibility, easy installation.
That being said, this research will attempt to reduce, at a macro-level, the uncertainty of SolarThermal Collectors market acceptance, in Germany, by applying the scenario planning theory – built on Intuitive Logics –by Derbyshire and Giovanetti (2017) to the business case provided by Company X. The objectives of this thesis are to (1) identifying the two most critical socio-economic driving forces and (2) developing four plausible scenarios for 2021. To achieve these objectives quantitative techniques such as seasonal forecasting technique, based on least squares, multivariate regression analysis, and the Bass growth model have been used. Also, qualitative techniques such as the conceptualization stage of system dynamics and the critical scenario method are used in the methodology of this research.
A hybrid solarcollector was designed to investigate the effects of combining two different solarcollector techniques on the overall collector’s effectiveness. While most solar collectors focus only on one solar collection method, the small hybrid system uses a flat plate collector in conjunction with five eva- cuated tubes to absorb the most energy possible from both direct and diffuse solar radiation. Data was collected over four months while the system oper- ated at different flow rates and with various levels of available insolation from the sun to evaluate the performance of the solarcollector. To understand the relative contribution of the flat plate collector and the evacuated tubes, tem- perature differences across each part of the system were measured. The re- sults indicate the average first law efficiency of the hybrid system is 43.3%, significantly higher than the performance of the flat plate alone. An exergy analysis was performed for this system to assess the performance of the flat plate system by itself. Results of the second law analysis were comparable to the exergetic efficiencies of other experimental collectors, around 4%. Though the efficiencies were in the expected range, they reveal that further improve- ments to the system are possible.
Solar water heating (SWH) is a technique in which the solar energy from the sun is used for water heating by the use of solarthermalcollector. In market a wide range of configurations are available for different environmental conditions. They are widely used for domestic and industrial usage. The working fluid is heated by a sun facing collector and passes into a storage system. They use water only, or the combination of water and antifreeze working fluid. Light concentrating mirrors are used for direct heating the system. Because mirrors can concentrate the sunlight into smaller collectors in heavy duty installations.
(CO) is a solarthermalcollector for heating water which is composed of two parts connected together in series. First part is a flat collector (FP), and second part is an evacuated tube collector (ET) of the type (U-pipe). Water enters the bottom of (FP) and exit the top of (ET). Reference area for the two collectors are equal, which are: Aperture area A a , Absorber surface area exposed to solar radiation A A , and Gross area A G . The Design and the manufacturing are as follows:
As the effect of the global warming is becoming noticeable, the importance for environmental sustainability has been raised. Parabolic trough solarthermalcollector system, which is one of the solutions to reduce the carbon dioxide emission, is a mature technology for electricity generation. Malaysia is a tropical country with long daytime, which makes suitable for solarthermal applications with parabolic trough solarthermal collectors. However, the high humidity causes the solar radiation to fluctuate. In order to simulate the solarthermal collectors’ performance at an early design stage of solarthermal power generation systems, fast still accurate transient thermal performance prediction methodis required. Although multiple transient thermal simulation methodologies exist, they are not suited especially at an early design stage where quick but reasonably accurate thermal performance prediction is needed because of their long calculation time. In this paper, a transient thermal prediction method is developed to predict exit temperature of parabolic trough collectors under fluctuating solar radiation. The method is governed by simple summation operations and requires much less calculating time than the existing numerical methods. If the radiation heat loss at the parabolic trough collector tube surface is small, the working fluid temperature rise may be approximated as proportional to the receiving heat flux. The fluctuating solar radiation is considered as a series of heat flux pulses applied for a short period of time. The time dependent solarcollector exit temperature is approximated by superimposing the exit temperature rise caused by each heat flux pulse. To demonstrate the capabilities of the proposed methodology, the solarcollector exit temperature for one-day operation is predicted. The predicted solarcollector exit temperature captures the trend of a finite element analysis result well. Still, the largest temperature difference is 38.8K and accuracy is not satisfactory. Currently, the accuracy of the proposed method is being improved. At the same time, its capabilities are being expanded.
Solar energy is one of the best candidates to produce process heat at mid temperatures to satisfy the industrial demand. The interest in improving solarthermalcollector efficiencies is huge, in order to take full advantage from this source of energy. TVPSolar is a leading company in the field of high-performance solar energy conversion that develops and produces an innovative flat-plate solarthermalcollector under high vacuum. Vacuum technology ensures that both gas convective and conductive losses are reduced to a negligible level, so that these flat-panels are able to reach high working temperatures (up to 200 °C) . Concentrating Solar Power technology (CSP), combined with high vacuum insulation, could be an alternative to reach higher working temperatures. The sunlight concentration technology splits into two different broad categories: imaging and non-imaging concentration. As regarding SolarThermal (ST) and photovoltaic (PV) applications, non-imaging concentration has been an interesting option, since mid-1960s . CSP usually uses only direct-beam sunlight , so mirrors require high cleaning standards and tracking systems to efficiently harness solar energy in day-light hours, resulting in high maintenance costs and installation issues. Compound Parabolic Concentrator (CPC) is an example of non-imaging concentration of sunlight that could be designed for stationary or passive tracking thus having acceptable concentration ratio. Moreover, it can collect both direct-beam sunlight and part of diffuse light (only rays within the acceptance angle)  and concentrate them on an absorber tube. A new frontier in high efficiency solar collection could be a high vacuum flat solar panel, thick enough to be equipped with CPC. The CPC installed in a high vacuum envelope leads to various advantages: no need for mirror cleaning, no corrosion due to atmospheric agents, better insulation resulting in thermal loss reduction, possibility to deposit a IR reflective coating on the interior side of the glass to benefit from ‘photon recycling’ mechanism . A pioneering work  has experimentally investigated the idea to place a CPC under vacuum to reach the high temperatures needed for methanol reforming but CPC dimensions and performances were limited by the small volume of the cylindrical vacuum chamber. To extend CPC sizes the vacuum chamber must increase too, so the surface under vacuum needs a mechanical support to sustain the glass against the atmospheric pressure and the CPC has to be designed to respect the support mechanical constraint.
The solarcollector is considered as the heart of a solarthermal system. The main function of the solarthermalcollector 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 Energy plays most important role in the persistence of living organs. The living quality and opulence of a nation vary directly with variation in the consumption of energy. The global energy demand is increasing rapidly due to industrial growth, population growth as well as increased and extensive use of electrical gadgets. In addition, the requirement of human being does not know no confines, at present most of the nation worldwide is experiencing the problem of energy shortages. The limited availability and depleting source of traditional fosil fuels have directed towards the use of non-conventional energy sources. About 25 % of India's energy use is in form of heat for processes up to 400 °C. Different thermal processes have different temperature and pressure requirements and they may use various heat conducting media such as steam, hot water, air, and thermal oil. India is active in the sector of utilizing solarthermal energy for both domestic use and industrial process heat for over two decades and is considered to be a global leader. It has worked on unique concepts and has first-hand experience in the design, installation, and operation of the first indigenous concentrating solar power plant in MW range. Today, the world is mainly concentrating on solar PV and wind energy technologies when it comes to electrical power generation, but these cannot easily be integrated with storage, thus limiting their penetration in the power grids. Solarthermal technologies will have significant role to play in this respect. Solar irradiance is one of the most promising sources of alternative energy available at free of cost worldwide. The increasing environmental apprehensions and the swelling conventional energy supply costs are creating a resurgence of curiosity in renewable energy resources. However, with the technological development one or more of these resources could be interfaced or coupled to extract maximum efficiency and obtain power output with a single usage. One of such technology is described here called as a solar photovoltaic thermal hybrid collector. This photovoltaic thermalsolar collectors, which is hybridize PV/T device that converts solar radiation into electrical energy as well as provides a thermal energy. These system combines a photovoltaic cell, which converts electromagnetic radiation (photons) into electricity, with a solarthermalcollector, which captures the remaining and incident excess energy and removes waste heat from the PV module.
I would like to acknowledge the generosity and patience shown by the administration at the Centre for Sustainable Energy Systems and the Faculty of Engineering and Information Technology during the last four years. I have had the opportunity to conduct an international study tour, attend local and international conferences, and to take some time out while working on the Bruce Hall solar project. Both CSES and FEIT have been generous with financial support and encouraged extra-curricular developmental activities. Thanks also to the now defunct CRC for Renewable Energy for their funding support and good fun post- graduate conferences.
olar water heaters are the most developed renewable energy technologies used in the world. For the past several years, conventional flat plate collectors have been well studied and developed. Their relatively low cost, lower maintenance and easy of construction have made these systems very competitive and are widely used all over the world especially for low temperature thermal systems. Conventional flat plate solar collectors use water pipes attached to the collecting where water circulates either naturally or forced inside the pipes and so transfers the heat collected by the plate to the storage tank. The following are some of the limitations of conventional flat plate solar collectors for water heating
Rangababu et al.  investigated FPC to improve thermal efficiency. The author highlighted that thermal efficiency could be improved by changing the parameters of the geometry or working fluid properties. They developed a CFD model with a heat flux boundary condition on the top and assumed other sides of the collector as fully insulated. Mixed radiation model was applied on the cover glass. Outlet water temperature was validated to analytical and experimental data with an error of 30% and 20% respectively. They reported an increase in the collector efficiency by 22% by using CuO nano fluid compared to water.
ABSTRACT: An experimental research has been performed to investigate and elicit a heat pipe evacuated tube solarcollector (HPET-SC) that subjected to mechanical vibration. The voltage ranges used to generate vibration frequency are 6, 8, 10 and 12 Volts. For comparison, two HPET-SC's were built identically. This comparison has been made based on the solarcollector effectiveness of in a presence and an absence of the vibration under Iraq's winter climatic conditions. In this study, a liquid of an Acetone was used as a working fluid inside the heat tube with 0.7 filling ratio. One of the outlet investigation results indicates that heat transfer coefficients of the evaporation and condensation increased with increasing of the vibrational frequencies. Another result, using the controllable vibration system led to increasing the two coefficients of heat transfer, the temperature of hot water and the total collector effectiveness by (25%), (15%), and (20%) respectively throughout the test conditions.
innovations are promising energy assets. The improvement in resources will expand nations energy security through dependence on an indigenous, unlimited and generally import-free asset, improve maintainability, lessen contamination, bring down the expenses of moderating environmental change, and keep non-renewable energy source costs lower than something else. The present business proficiency of photovoltaic innovation has achieved over 20%, thermal innovation has accomplished efficiencies of 40-60%  . Besides, as indicated by  , solar
A significant fraction of the total energy consumed in residential and commercial sectors in North America and Europe is utilized in water heating. According to a 2004 estimate, about 23% of the natural gas reserve for the residential consumption was spent for water heating alone in the United States . Solar water heating is one of the commercialized renewable energy technologies in use nowadays. The most common type of solar water heaters consist of flat plate collectors. Many efforts have been made in the past to improve their performance such as collector insulation, use of heat absorbing coatings, etc. The absorber area of a flat plate collector is equal to the area receiving the solar radiation  and since maintaining the compactness of the collector is a major consideration, enhancing the convective heat transfer coefficient may be an alternate way to increase collector’s efficiency. Various methods that have been employed so far in this concern can be broadly divided into two categories; active techniques and passive techniques. Active techniques involve mixing of the fluid by means of external power such as surface rotation or vibration, application of electrostatic fields, jet impingement, etc. In contrast, passive modes include usage of fins or extended surfaces, increased surface roughness or the employment of insert devices of various geometries to intensify turbulence and hence fluid mixing, and thus, augmenting Nusselt number.
Thermal diode is important in designing of solar collectors, where heat is transferred only from the evaporator to the condenser, but never in the reverse direction. This feature can cut off the heat loss when the absorber temperature is lower than that of the liquid in the heat exchanger [4-7]. Several studies on heat pipe solar collectors are reported in the literature. Riffat, et al  studied developing a theoretical model to investigate thermal performance of a thin membrane heat-pipe solarcollector. In their work thin membrane heat- pipe solarcollector was designed and constructed to allow heat from solar radiation to be collected at a relatively high efficiency while keeping the capital cost low. Azad  investigated the heat pipe solarcollector theoretically and experimentally,