scholarly journals Design, Modeling, and Experimental Investigation of Active Water Cooling Concentrating Photovoltaic System

2020 ◽  
Vol 12 (13) ◽  
pp. 5392 ◽  
Author(s):  
Mohamed R. Gomaa ◽  
Mujahed Al-Dhaifallah ◽  
Ali Alahmer ◽  
Hegazy Rezk

This work presents performance study of a concentrating photovoltaic/thermal (CPV/T) collector and its efficiency to produce electric and thermal power under different operating conditions. The study covers a detailed description of flat photovoltaic/thermal (PV/T) and CPV/T systems using water as a cooling working fluid, numerical model analysis, and qualitative evaluation of thermal and electrical output. The aim of this study was to achieve higher efficiency of the photovoltaic (PV) system while reducing the cost of generating power. Concentrating photovoltaic (CPV) cells with low-cost reflectors were used to enhance the efficiency of the PV system and simultaneously reduce the cost of electricity generation. For this purpose, a linear Fresnel flat mirror (LFFM) integrated with a PV system was used for low-concentration PV cells (LCPV). To achieve the maximum benefit, water as a coolant fluid was used to study the ability of actively cooling PV cells, since the electrical power of the CPV system is significantly affected by the temperature of the PV cells. This system was characterized over the traditional PV systems via producing more electrical energy due to concentrating the solar radiation as well as cooling the PV modules and at the same time producing thermal energy that can be used in domestic applications. During the analysis of the results of the proposed system, it was found that the maximum electrical and thermal energy obtained were 170 W and 580 W, respectively, under solar concentration ratio 3 and the flow rate of the cooling water 1 kg/min. A good agreement between the theoretical and experimental results was confirmed.

Electronics ◽  
2018 ◽  
Vol 7 (7) ◽  
pp. 119 ◽  
Author(s):  
Muhammad Khan ◽  
Kamran Zeb ◽  
Waqar Uddin ◽  
P. Sathishkumar ◽  
Muhammad Ali ◽  
...  

Environment protection and energy saving are the most attractive trends in zero-carbon buildings. The most promising and environmentally friendly technique is building integrated photovoltaics (BIPV), which can also replace conventional buildings based on non-renewable energy. Despite the recent advances in technology, the cost of BIPV systems is still very high. Hence, reducing the cost is a major challenge. This paper examines and validates the effectiveness of low-cost aluminum (Al) foil as a reflector. The design and the performance of planer-reflector for BIPV systems are analyzed in detail. A Bi-reflector solar PV system (BRPVS) with thin film Al-foil reflector and an LLC converter for a BIPV system is proposed and experimented with a 400-W prototype. A cadmium–sulfide (CdS) photo-resistor sensor and an Arduino-based algorithm was developed to control the working of the reflectors. Furthermore, the effect of Al-foil reflectors on the temperature of PV module has been examined. The developed LLC converter confirmed stable output voltage despite large variation in input voltage proving its effectiveness for the proposed BRPVS. The experimental results of the proposed BRPVS with an Al-reflector of the same size as that of the solar PV module offered an enhancement of 28.47% in the output power.


2003 ◽  
Vol 125 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Gunnar Tamm ◽  
D. Yogi Goswami

A combined thermal power and cooling cycle proposed by Goswami is under intensive investigation, both theoretically and experimentally. The proposed cycle combines the Rankine and absorption refrigeration cycles, producing refrigeration while power is the primary goal. A binary ammonia-water mixture is used as the working fluid. This cycle can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using low temperature sources such as geothermal and solar energy. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulation. Results showed that the vapor generation and absorption condensation processes work experimentally, exhibiting expected trends, but with deviations from ideal and equilibrium modeling. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses showed where improvements could be made, in preparation for further testing over a broader range of operating conditions.


Author(s):  
G. G RajaSekhar ◽  
Basavaraja Banakara

This paper presents the performance of Brushless DC (BLDC) Motor drive with only one positioning sensor instead of three conventional sensors. The three sensor units are replaced with a single stator current sensor unit in DC bus which further reduces the cost increasing the reliability of the drive system. Using a single sensor in stator requires minimum electronic equipment for the purpose of measurement process. This paper evolves the BLDC motor drive fed from PV system. A high voltage-gain DC-DC converter is presented in this paper to step-up the voltage from PV system. The appropriateness of PV fed BLDC motor drive is verified for variable increamental speed with fixed torque and variable decremental speed with fixed torque operating conditions. BLDC motor drive performance is also performed for variable torque with fixed peed working condition. The proposed system and results are developed using MATLAB/SIMULINK software.


2021 ◽  
Vol 6 (3(31)) ◽  
pp. 35-38
Author(s):  
Yuliya Aleksandrovna Mironova ◽  
Svetlana Aleksandrovna Dedeeva

This article presents the basic principles of pricing in the economy, examines the factors influencing the formation of tariffs in the energy sector. Using the example of the Sakmarskaya termal power stantion, the categories that determine the cost of finished products are distinguished. Measures are proposed that can reduce production costs and thereby reduce the cost of electric and thermal energy by about 1.5 times.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3773
Author(s):  
Kamran Zeb ◽  
Tiago Davi Curi Busarello ◽  
Saif Ul Islam ◽  
Waqar Uddin ◽  
Kummara Venkata Guru Raghavendra ◽  
...  

The novelty behind the research in this paper is to investigate the Super Twisting Sliding Mode Controller (ST-SMC) for efficiently injecting both active and reactive power under normal and abnormal operating conditions for a three-phase grid-connected photovoltaic (PV) system. The ST-SMC is aimed to inject sinusoidal current to the grid with low Total Harmonic Distortion (THD), to avoid chattering with easy real implementation, and to enhance the quality of disturbance rejection and sensitivity to parameter variation. The test under normal conditions includes initialization, steady state behavior, dynamic behavior, and interrupting the injection of acting and reactive power while the abnormal conditions consists of voltage sag, voltage swell, frequency variation, DC-link variation, and inclusion of 5th harmonics, etc. The phase lock loop used for synchronization is based on a synchronous reference frame that works well under distorted grids and nonideal. Automatic code is generated in PSIM 9.1 for hardware implementation in the DSP board TMS32F28335 from Texas Instruments while code composer studio 6.2.0 is used for debugging. The real time testing is executed using Typhoon Hardware in Loop (HIL) 402 device on the DSP board. The results authenticate the fastness, effectiveness, and robustness for both steady state and dynamic behavior under various scenarios of the designed controller.


2013 ◽  
Vol 330 ◽  
pp. 203-208 ◽  
Author(s):  
L. Bruno Augustin ◽  
Jigar Golecha ◽  
K.G. Sai Shreenaath ◽  
Vishnu Swami ◽  
M. Suresh

Increase in the consumption of electrical energy worldwide has laid the emphasis on replacing electrical energy with thermal energy wherever possible. In this paper, the bubble pump, which is ‘heart’ of diffusion- absorption refrigeration system, has been investigated numerically. A thermally driven bubble pump, which can be powered by waste heat or solar thermal energy, is used to lift the liquid. As a result of the absence of any mechanical moving part, the refrigerator is silent and very reliable in addition to aneconomicalandenvironmental friendlydevice. The concept of such a pump is already in existence but optimization studies are yet to be extensively investigated. This paper deals with the optimization of various parameters of the bubble pump usingwateras the working fluid. Parametric studies are carried out and a design optimization for maximum efficiency is performed for various operating conditions.Numerical simulation of the bubble pump is carried out using simple numerical equations which assume slug flow in the bubble pump. The diameter of the pipe and the position of the heating element are varied and the effect it has on time taken, pumping ratio and pumping ratio for one pumping cycle is studied.


2017 ◽  
Author(s):  
Aldo López Vega ◽  
Gregory J. Kowalski ◽  
Carlos Rubio-Maya ◽  
J. Jesús Pacheco Ibarra

Shopping malls require large amount of electrical and thermal energy to provide quality services and maintain customer’s comfort. Conventionally, electrical energy for direct use and operation of HVAC systems is supplied directly from the electrical grid and is produced in remote power plants that burns fossil fuels. Thermal energy for hot water or heating supply is usually produced by boilers that use LP gas or fuel oil. Given these conditions, cogeneration and trigeneration systems supported by renewable sources of energy are ideal schemes to meet energy needing in a more efficient and cost-effective manner. For this reason, a hybrid trigeneration/photovoltaic system has been installed to cover approximately 50% of the electrical and thermal demands of a shopping mall complex, located in Morelia (MichoacÁn, Mexico). The trigeneration plant consists of a microturbine with an electric power output of 65 kW, three absorption chillers with an output of 5 RT each and a photovoltaic system of 30 kW of electrical power, composed of 108 photovoltaic modules of 280 W each. The Incentive Program for Technology Innovation of the National Council of Science and Technology has funded and sponsored the project and it is to demonstrate on-site feasibility under the Mexican energy context. The installation will generate information on the global and specific operation of the components. In this paper, the development and validation of thermodynamic models to analyze and simulate the individual and integral operation of the hybrid trigeneration/photovoltaic system components is presented. These models based on the First and Second law will allow an integral simulation of the plant to determine the most appropriate operating conditions. The First and Second law efficiencies as well as the exergy destruction in each component is reported. The models have been developed from data provided by manufacturers and the application of mass, energy and exergy balances. The validation of models has been carried out using experimental data acquired directly from the components of the plant and other measurement instruments that have been used for this purpose. The results of the models have been compared with experimental data and have showed satisfactory agreement, with an average difference of 2.92%.


Author(s):  
Joseph Dix ◽  
Amir Jokar ◽  
Robert Martinsen

The objective of this study is to analyze the single-phase fluid flow and heat transfer through a microchannel electronics cooler with a hydraulic diameter of about 300 microns. For this purpose, commercial computational fluid dynamics software was used to first characterize the existing design that uses purified water as coolant fluid. The flow parameters of the cooler were then adjusted in order to optimize the design. Geometry modifications were used next to enhance heat transfer, and to reduce pressure drop and erosion from possible impurities in the working fluid. Different working fluids were also considered to investigate possible reductions in corrosion and further increases in heat transfer. Alternative combinations of boundary and operating conditions were explored during optimization. The results of this study showed the microchannel cooler had capacity in rejecting more thermal energy with less pressure drop through flow optimization and geometry modification.


Author(s):  
James H. Anderson

Ocean thermal energy plants are thermal power plants that use warm ocean surface water as a source of heat and cold seawater from the deep ocean as a heat sink. A historical perspective along with the development of the technology will be presented. A short description describing the subtle differences between OTEC and fossil and nuclear plants will be presented. Open cycle OTEC and closed cycle OTEC will be described with a focus on the influence of choice of working fluid on the design of a plant. Various working fluids could be selected for use in closed cycle OTEC plants. A review and comparison of potential working fluids will address the advantages and disadvantages of the individual fluids. Their characteristics along with a comparison to water as a working fluid in open cycle OTEC will be explained.


2020 ◽  
pp. 165-165
Author(s):  
Mukundjee Pandey ◽  
Biranchi Padhi ◽  
Ipsita Mishra

In today?s world, we are facing the problem of fossil fuel depletion along with its cost continuously increasing. Also, it is getting difficult to live in a pollution free environment. Solar energy is one of the most abundantly and freely available form of energy. Out of the various ways to harness solar en-ergy, solar thermal energy is the most efficient as compared to photo-voltaic technology. There are various cycles to convert the solar thermal energy to mechanical work, but Kalina cycle (KC) is one of the best candidates for high efficiency considerations. Therefore, the authors have proposed a novel KC having the double separator arrangements to increase the amount of ammonia vapors at the inlet of turbine, and hence have tried to minimize the pumping power for Double Separator Kalina Cycle (DS-KC) by reducing the fraction of gas/vapors through it. Here, in this paper we have tried to com-pare Organic Rankine Cycle (ORC), Brayton Cycle (BC) and Double Sepa-rator Kalina Cycle (DS-KC) for low temperature heat extraction from para-bolic trough collectors having arc-circular plug with slits (PTC). The effect of different operating conditions; like the number of PTCs, mass flow rate of fluids in different cycles, pressure difference in turbine are analyzed. The ef-fect of these different operating conditions on different parameters like net work done, heat lost by condenser, thermal efficiency and installation cost per unit kW for DS-KC, ORC and BC are studied.


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