Cylindrical Parabolic Collector Research Articles

Thermodynamic and Thermo-Economic Analysis of a Solar-Integrated Double-Turbine Kalina Cycle for Varying Solar Flux Conditions

Abstract Kalina cycle is established as a reliable low-grade energy cycle working on solar, geothermal, and other waste heat recovery sources. This work aims to develop a novel methodology for optimizing a Kalina cycle according to the solar irradiation. A comprehensive analysis of performance is conducted by varying the parameters of the Kalina system, modeled with high- and low-pressure turbines. The present work implements and analyzes the performance of a multi turbine Kalina cycle with cylindrical parabolic collectors for energy input at different time, on a particular day, for a location. The proposed cycle is modeled to simulate the working. The dependency of parameters—separator pressure, concentration of ammonia in boiler, intermediate separator temperature and vapor fraction at condenser side turbine exit—on the system performance is investigated. Optimization is conducted using genetic algorithm with net power as objective function for different solar irradiations. The optimized power values are 282.62, 246.75, 222.31, and 180.0 kW for solar influxes 507.7, 461.8, 413.9, and 321.0 W/m2 respectively. The results show that the proposed model can be adopted for better performance. A thermo-economic analysis of an optimized output is conducted to conclude on capital investment and operation cost for sustainable power production. The analysis yields highest cost rate of exergy destruction of 58936.41$/year for the boiler. The investment cost of the turbines together is 89% of the total capital investment, and hence, thermo-economic factor is highest for these components.

Analysis of the Effect of Transparent Covers on Receiver of Cylindrical Parabolic Solar Collectors

Parabolic solar collectors with central receiving systems are preferred due to their high efficiency despite their high initial investment and operating costs. In this study, the effect of two glass covers on tubular collector will be investigated, aiming enhancement of cylindrical parabolic solar collectors’ efficiency. By using glass cover it is aimed to decrease losses and increase efficiency. In order to investigate the changes of losses and instantaneous efficiency, a model was constructed considering all parameters of the structure, optical losses, material properties and outdoor climatic conditions. Results of calculations show that the two-cover system is not more efficient than the single cover system at low fluid temperatures between 0 and 500 K and the efficiency of the two-cover system is increased at medium fluid temperatures between 500 and 700 K.

Thermal efficiency improvement of a solar desalination process by parabolic trough collector

Abstract Nexus water/energy security is one of the main global challenges for the future generation. Solar distillation (thermal process) represents a sustainable solution to water shortages and energy crisis in the world especially in the Middle East and North Africa region. The technique is based on a evaporation–condensation process via heat delivery through a cylindrical parabolic collector to a thermal energy storage, in the form of sand integrated into the solar still, to maximize water production efficiencies. It is a technically feasible and operational method. Results suggest that the additional solar collector flux has a direct impact on the increase in average sand and seawater temperature particularly over the period between 12 p.m. and 4 p.m. Seawater temperature increases by >26.6%. The energy stored quantity delivered for the distiller basin grows proportionality with the sand temperature, which is depending directly for the solar collector absorber temperature. The difference between the both temperatures defines a decreasing rate of −19%. The daily water production by the hybrid solar distiller is 6.5 l/day, it represents an increase of +91% compared to the traditional concrete solar still production (3.4 l/day), for the same geometry and meteorological conditions.

Performance of cylindrical parabolic solar collector with the tracking system

A parabolic solar collector collects the radiant energy emitted from the sun and focuses on a point. Parabolic trough collectors are the low-cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer fluid. However, the fundamental problem with the cylindrical parabolic collector without tracking was that the solar collector does not move with the sun's orientation. The development of an automatic tracking system for cylindrical parabolic collectors will increase solar collection and the efficiency of devices. The present study of this project work presents an experimental platform based on the design, development, and performance characteristic of water heating by tracking solar cylindrical parabolic concentrating system. The tracking mechanism is to be made by stepper motor arrangement to receive the maximum possible energy of solar radiation as it tracks the sun's path. The performance of the parabolic trough collectors is experimentally investigated with the water circulated as heat transfer fluid. The collector efficiency is calculated.

Exergy and thermo-economic analyses of various tubular solar still configurations for improved performance

ABSTRACT Solar energy is being used for the purpose of water distillation since long. The present work demonstrates the comprehensive experimental investigation of various heat transfer enhancement arrangements on tubular solar still for its performance improvement. These arrangements include; case-1: Tubular solar still (TSS) with flat plate basin (TSS-FP), case-2: TSS with U-corrugated basin (TSS-UA), case-3: TSS with the coupled cylindrical parabolic collector (TSS-CPC). According to the available literature, the exergy and economical analysis of tubular solar stills are not explored much in the previous studies. Thus, a comparative thermo-economic analysis, exergy analysis and system productivity analysis have been carried out. In addition to this, the study investigates the effects of different basin water depths on system productivity. It has been found that the case-3: TSS-CPC gives the highest productivity; it was 37.75% and 80.63% higher as compared to the case-2 and case-1 respectively. Also, in the same arrangement, the enhancement in the exergy efficiency was around 48.6% and 85.2% as compared to case-2 and case-1 respectively. The per liter cost of water obtained by TSS-FP, TSS-UA, and TSS-CPC were about 0.00592, 0.00511, and 0.00567 US $/m2 respectively. The study concludes that the U-Corrugated basin surface, less basin water depth, and the secondary heating arrangement improve the productivity of the tubular still significantly.

Performance analysis of cylindrical parabolic solar collector with twisted tape on solar radiation

In this paper, an analytical study of thermal enhancement and performance of cylindrical parabolic collector with twisted tape insert in the absorber tube for different insolation has been studied. The performance of the collector has been improved by using different system parameters and operating parameters such as heat gain, heat loss, overall heat loss coefficient, and outlet fluid temperature. These studies are carried out to find the changes in thermal efficiency and the thermal performance of the collector. The effect of insolation and the rate of mass flow of thermic fluid were also investigated.

ANN Modeling and experimental study of the effect of various factors on solar desalination

Abstract This study investigated a novel method for increasing desalinated water mass in solar desalination plants. For this purpose, solar panels and a cylindrical parabolic collector (CPC) were used to raise basin water temperature. The effect of different components of basin solar still on freshwater mass was also investigated. The aluminum basin has been associated with maximum water desalination among the different materials constituting a basin. The effects of different colors (e.g. black, brown, and red) on the basin, as well as different water depths (5, 10, and 15 mm), were also explored. The highest amount of freshwater in the black aluminum basin at a 5-mm water depth was 2.97 kg/day. ANN modeling was employed to validate the experimental data, indicating good compliance of experimental data with ANN prediction. According to the results of the simulation with varying numbers of neurons (n = 2–25), the highest and lowest agreement between experimental data and ANN prediction data were related to 24 and 10 neurons, respectively. Under optimum conditions, R2 and %AAD error were 0.993 and 2.654, respectively.

First principles versus artificial neural network modelling of a solar desalination system with experimental validation

ABSTRACT The present study mainly focuses on enhancing the performance of solar still unit using solar energy through cylindrical parabolic collector and solar panels. A 300 W solar panel is used to heat saline water by thermal elements outside the solar still unit. Solar panels are cooled during the hot hours of the day; thus, reducing their temperature may lead to an increase in solar panel efficiency followed by an increase in the efficiency of the solar still unit. The maximum amount of freshwater used in the experiment was 2.132 kg/day. The experiments were modelled using ANNs. Based on neural network simulation results, there is a significant correlation between experimental data and neural network modelling. This paper compares experimental data with data obtained from mathematical modelling and ANNs. As a conclusion, the artificial neural network prediction has been more accurate than the simplified first principles model presented.

Effect of regeneration heat and energy storage on thermal drying performance in a hardwood solar kiln

The use of energy efficiency tools and solar energy in wood drying can help reduce the often heavy energy consumption of industrial dryers. The rational management of energy in terms of drying has attracted a lot of attention and the main objective of this work is to adapt the techniques of renewable energy and energy saving in solar kilns. The present work is therefore a contribution to the improvement of energy efficiency and the modeling of a solar wood kiln with thermal storage and heat regeneration. The drying system consists of five main units, a drying chamber, a multi-pass solar air collector, a cylindrical parabolic solar collector, a thermal storage tank and a Closed Feed Air Heater. The investigation carried out in this work is based on the establishment of mass and energy conservation equations in different components of the drying system. The governing equations of heat and mass transfer are solved using the implicit finite difference method. The discrepancies between the experimental and numerical results do not exceed 5%. The results show that the drying time is shorter in June and longer in December. The drying time decreases as the collector area increases and the boards thickness decreases. By incorporating a Closed Feed Air Heater with an effectiveness of 0.75, in the solar dryer, the collector and drying efficiency values are increased from 0.48 to 0.56 and 0.43 to 0.88, in June, respectively. The integration of the thermal storage unit in the solar kiln has the effect of reducing the drying time up to 40 and 60%, in June and December, respectively. Moreover, the combined use of thermal storage and regeneration heat is efficient in reducing the energy consumption ratio (kWh.m−3) up to 50% and 54%, in June and December, respectively. The proposed solution can significantly improve thermal drying performance and thus overcoming the problem of longer drying time, especially in winter.

Modeling and Analysis of Zenith based Passive Solar Tracking Mechanism

A novel gravity-based, power-free solar tracking mechanism is being developed to track the movement of the sun across day length. A compound parabolic collector having 3 parabolic segments is chosen due to its high intercept factor and suitability to the current tracking as compared to a cylindrical parabolic collector. Used to concentrate the incident solar radiation to the focal point, the Compound Parabolic Collector accumulates heat at the central coil, which is in turn used for process heating applications. The working of the tracking mechanism is studied to find the tracking loads in the east and the west sides of collector. We intend to simulate the tracking motion from the sunrise to sunset, in order to validate the empirical findings. The identified design variants are sprocket wheel diameter, suspension, solar collector’s weight, counter balance and loading on the shaft. The recommended diameter for the sprocket wheel and shaft is 2500mm and 50mm respectively.

An experimental study on the effects of direct and indirect use of solar energy on solar seawater desalination

Abstract The use of solar energy for increasing the amount of water heating inside the solar still unit provided an important basis for various process designs in this research. Concerning the wide use of solar energy, solar panels have been used for heating water through thermal elements. In the first setup, a cylindrical parabolic collector (CPC) was used together with 300-watt and 500-watt solar panels, the results of which were then compared with each other. Based on the results the system best performed when more powerful solar panels and a longer CPC device were used. In the second setup, solar heating was achieved by direct use of solar still units. According to comparative results between the two experimental setups, the use of direct thermal elements in the solar still unit provided better performance compared with the use of indirect thermal energy. The highest amounts of freshwater were 3.679 kg and 3.945 kg per day in the first and the second setups, respectively.

Experimental investigation of the effect of using the cylindrical parabolic collector, different solar panels and their cooling on seawater desalination in double-slope solar still

ABSTRACT The present study was aimed at examining the effect of using solar panels and cylindrical parabolic collectors, or CPCs, on solar still unit. Cooling of the solar panels up to 25°C has been also conducted in order to rise the amount of produced freshwater. In the first setup, the solar still unit has been made up of 300 W and 600 W solar panels along with the CPC devices of lengths 1 m and 2 m outside for water heating. The second setup was designed in a way that water is heated by the solar panels as well as the CPC device with the copper pipe circulation inside the solar still unit, so the hot water within the pipe has raised the temperature of the water as a heat exchanger inside the solar still. Based on the results, the second setup had a higher efficiency than the first setup. Moreover, the highest amount of fresh water was 4.215 kg and 5.091 kg during one day in the first setup and the second setup, respectively. Cases 1 to 6 are related to the first setup and cases 7 to 12 are related to the second setup. The lowest fresh water production in case 1 was 2.852 kg. the highest water temperature in experimental setup 1 was 71.9 °C and in experimental setup 2 was 84.8°C.

Computational drying model for solar kiln with latent heat energy storage: Case studies of thermal application

The use of solar energy in wood drying systems can reduce the often-heavy energy bill that manufacturers in this promising sector complain about. In this context, the study of solar kilns has received increasing attention and the work presented in this paper is a contribution for developing theoretical investigation during drying process of wood using solar energy. The system of drying consists of four units, solar air collector, cylindrical parabolic solar collector, drying and thermal storage unit. Two mathematical models of storage and drying are developed. The governing equations are solved by Newton Raphson's method for storage and finite difference techniques for the drying model. The results show that the size of the latent storage unit increases when the temperature level is raised. The integration of thermal storage unit into the solar kiln has the effect of reducing the drying time up to about 26.5%. The recovered heat process is efficient to improve markedly the amount of the energy supplied to the drying unit and reduce drying time up to about 47%. The effect of choosing the phase change material on the thermal storage unit is significantly important in terms of increasing the evaporation capacity and drying efficiency. • The integration of the thermal storage unit in the solar kiln reduces the drying time as much as 26.5%. • The process of heat recovery reduces the drying time as much as 47%. • The maximum energy saving in the drying system was 482 KWh • The maximum drying efficiency of the solar dryer was 85%. • The maximum evaporation capacity of the dryer without recovery process was 5.4 × 10 −6 kg/m 2 ·s.

Performance of Cylindrical Parabolic Collector with Automated Tracking System

Parabolic solar collector collects the radiant energy emitted from the sun and focuses it at a point. Parabolic trough collectors are the low cost implementation of concentrated solar power technology that focuses incident sun light on to a tube filled with a heat transfer fluid. However, the basic problem with the cylindrical parabolic collector without tracking was the solar collector does not move with the orientation of sun. Development of automatic tracking system for cylindrical parabolic collectors will increase solar collection as well as efficiency of devices. The main aim of this paper is to design, fabricate and analyze the performance of parabolic collector with automated tracking system. The automated tracking mechanism is used to receive the maximum possible energy of solar radiation as it tracks the path of sun. The performance of the parabolic trough collector is experimentally investigated with the water circulated as heat transfer fluid. The collector efficiency will be noted.

Experimental Study on Performance Enhancement of Evacuated Tube by Constant Heat Flux Mode

The evacuated tube collector with U shape copper absorber tube is considered for the analysis. The experimental investigation is conducted on parabolic trough collector with U shape tube as absorber tube. The effect of the sudden fluctuations in the solar radiation on the performance of the collector is reduced by means of evacuated tube collector filled with thermic fluids. The analysis is performed with different thermic fluids such as dowtherm, therminol66, glycol water and ethylene glycol, are filled in the annular space between inner glass tube and U shape copper absorber tube. The experimentation is carried out at various mass flow rates from 20 to 100 LPH with the step-up flow rate of 20 LPH. A comparative study is carried out on various parameters such as effect of mass flow rate over instantaneous efficiency, useful heat gain and work input, etc. The characteristic curve of cylindrical parabolic trough collector (PTC) is also discussed. Experimental results show that, ethylene glycol gives better efficiency over mass flow rate and therminol66 gives best power heat ratio. Heat transfer mediums and its properties [specific heat capacity, thermal conductivity and dynamic viscosity] for all specified heat transfer fluids are also discussed. The results obtained with various specified heat transfer fluids filled in the annulus space of evacuated tube are compared with plain evacuated tube. It is observed that there is significant enhancement of overall instantaneous collection efficiency of the parabolic trough collector.

A new approach for obtaining angular acceptance function of non-perfect parabolic concentrating collectors

A new approach to calculate the angular acceptance function of cylindrical parabolic collectors has been developed. The procedure is rapid, simple and enables obtaining the acceptance function with or without absorber deviations. In a simple way, it registers the view angle of an eye slipping along the reflector surface. In case there are deviations, as a result of loss of symmetry, the function splits into four branches: two for the right and left hand side of the reflector section and two for the left and right hand side of the light cone reaching the aperture. As a result of deviations some branches are affected by windows where sun light escapes, reducing the optical efficiency of the collector. Deviations are computed as: (a) distance (d) between parabola focus and deviated absorber center and (b) rotation angle of the absorber (ω). Examples of perfect and non-perfect collectors are given and a variety of situations simulated: distance (d) varying between 0 and 1.0∗Rabs and rotation angle (ω) between (−90°) and (+90°). A procedure to generate angular acceptance functions monotonically decreasing with the view angle is described and discussed. Results are exposed as sensitivity curves where the main parameters of the angular acceptance function are registered. The method described enables to map a large variety of optical configuration errors, which can be used for quality tests, design procedures and collectors development. Non-parabolic geometries can also be treated with a similar procedure, showing that the method developed is a general and versatile approach.

Modeling and validation of a parabolic solar collector with a heat pipe absorber

Cylindrical parabolic solar concentrators of small concentration ratio are attractive options for working temperatures around <TEX>$120^{\circ}C$</TEX>. The heat gained can be utilized in many applications such as air conditioning, space heating, heating water and many others. These collectors can be easily manufactured and do not need to track the sun continuously. Using a heat pipe as a solar absorber makes the system more compact and easy to install. This study is devoted to modeling a system of cylindrical parabolic solar concentrators of small concentration ratio (around 5) fitted with a heat pipe absorber with a porous wick. The heat pipe is surrounded by evacuated glass tube to reduce thermal losses from the heat pipe. The liquid and vapor flow equations, energy equation, the internal and external boundary conditions were taken into consideration. The system of equations was solved and the numerical results were validated against available experimental and numerical results. The validated heat pipe model was inserted in an evacuated transparent glass tube as the absorber of the cylindrical parabolic collector. A calculation procedure was developed for the system, a computer program was developed and tested and numerical simulations were realized for the whole system. An experimental solar collector of small concentration, fitted with evacuated tube heat pipe absorber was constructed and instrumented. Experiments were realized with the concentrator axis along the E-W direction. Results of the instantaneous efficiency and heat gain were compared with numerical simulations realized under the same conditions and reasonably good agreement was found.

Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application

Concentrating collectors absorbs solar energy and convert it into heat for generating hot water, steam at required temperature, which can be further used for solar thermal applications. The developing countries like India where solar energy is abundantly available; there is need to develop technology for harnessing solar energy for power production, but the main problem associated with concentrating solar power technology is the high cost of installation and low output efficiency. To solve this problem, a prototype cylindrical parabolic solar collector having aperture area of 1.89 m2 is designed and developed using low cost highly reflecting and absorbing material to reduce initial cost of project and improve thermal efficiency. ASHRAE Standard 93, 1986 was used to evaluate the thermal performance and it was observed that this system can generate hot water at an average temperature of 500C per day with an average efficiency of 49% which is considerable higher than flat plate solar collectors. Hot water produced by this system can be useful for domestic, agricultural, industrial process heat applications.Article History: Received Sept 19, 2015; Received in revised form Dec 23, 2015; Accepted February 2, 2016; Available online How to Cite This Article: Bhujangrao, K.H. (2016). Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application. International Journal of Renewable Energy Development, 5(1), 49-55 http://dx.doi.org/10.14710/ijred.5.1.49-55

Design and Development of Cylindrical Parabolic Collector for Hot Water Generation

Today’s India is in need of generating power at higher rate to maintain adequate supply of electricity to users for development and growth of Nation. Non renewable energy sources like coal and petroleum products are the major sources utilized for power production. To reduce the gap between demand and supply of energy and maintain sustainable development, renewable energy sources need to be considered as an alternative source of energy. The solar energy has been identified as one of the promising energy source which can be used directly or indirectly for generation of electricity, hot water and power. A prototype of cylindrical parabolic collector (CPC) is designed and developed to utilize solar energy for hot water generation. Prototype of CPC is tested from 10AM to 4PM in the month of May and thermal performance is evaluated based on solar standards available through literature. Hot water at 600C is produced throughout a day by varying mass flow rate of water. The instantaneous efficiency is calculated after every half an hour and found to be 69% and overall efficiency of system is 71%. This prototype CPC system can deliver hot water at required temperature to meet industrial, domestic demands and saves electricity.

Performance of Closed Cylindrical Parabolic Trough Collector for Solar Thermal Application

A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild steelcoated with black zinc having absorptivity of 0.94 were used for CPT. mass flow rate of working fluid was 4 l/h. Thermal performance of CPT collector was tested according to ASHRAE Standardmethods. Average instantaneous efficiency of closed cylindrical parabolic trough collector system was found to be 66%. The overall efficiency of CPT system is 71% which is best suited for solar thermal applications.