Solar Engineering Of Thermal Processes

Techno-economic assessment of performance-enhanced parabolic trough receiver in concentrated solar power plants

Among the different kinds of renewable energy sources, solar energy plays a major role because it is safe and inexpensive at all times. Several techniques are developed for steam and electricity generation by solar energy, in which the parabolic trough collector is an advantageous method for generating steam and electricity. Different types of collectors for various temperatures, in which PTCs are used to produce medium temperature ranges using the readily available solar energy, were developed, produced, and tests. Many theoretical and experimental studies have been carried out to improvise parabolic trough collectors’ optical and thermal characteristics. The modifications are reviewed in this paper to enhance the design modification, optical and thermal properties utilized in the collector. This analysis paper also elucidates the use of PTC desalination, various integrated parabolic trough collector methods for power generation, and the economic aspects of parabolic trough collector.

Comprehensive review on various parameters that influence the performance of parabolic trough collector

CFD analysis of Al2O3-syltherm oil Nanofluid on parabolic trough solar collector with a new flange-shaped turbulator model

The main goal was to investigate the efficiency of the parabolic trough solar collector (PTSC) by using U-tube as an absorbent and Nickel Ferrite (NiFe2O4) nanofluid as new working fluid. An experimental test bench for testing collector was designed and developed at Vali-e-Asr University. By using the two-step procedure, Nickel Ferrite nanofluid was prepared. Efficiency of PTSC was experimentally studied by using Nickel Ferrite nanofluid with two volume fraction of 0.01 and 0.05% as well as deionized water as the working fluid. Also, the experiments were carried out in three different volume flow rates ranging from 0.5 to 3 Lit/min. The performance index (PI) analysis revealed that the application of Nickel Ferrite nanofluid at high flow rates was far more effective and suitable in the PTSC. Also the result showed that absorbent with U-tube was more effective than absorbent without U-tube. Maximum efficiency of 51% was related to the Nickel Ferrite nanofluid with U-tube as an absorbent at a volume fraction of 0.05% with a flow rate of 3 Lit/min, which was 22% higher than that of the pure water. The results indicated that the thermal efficiency of PTSC improved with the flow rate and the volume fraction of the nanofluid.

Efficiency of the parabolic through solar collector using NiFe2O4/Water nanofluid and U-tube

Futuristic decentralized clean energy networks in view of inclusive-economic growth and sustainable society

World climate is an area of concern due to the use of fossil fuels that have been the most commonly preferred resource of energy since the industrial revolution and urbanization. The target to maintain the lowest level of carbon emissions and greenhouse gases has created an urge to look for renewable energy resources. Among the renewable energy resources available worldwide, solar energy is considered as one of the feasible and mature technologies in view of large-scale commercial deployment. Solar photovoltaic and solar thermal conversion (STC) techniques have been implemented so far and are still advancing towards cost-effective solutions. Parabolic trough collector (PTC) is one such economical and feasible STC technology as far as high-temperature thermal applications are concerned and are being widely used for power generation. This paper is an attempt to present the current scenario of PTC technology along with its various advancements over the years. Further in this paper, selective coatings, coating techniques and heat collection element (HCE) or receiver are discussed in detail with regard to their advancements. The present work also illustrates the progressive trends in PTC technology, particularly with respect to various heat transfer fluids, HCE inserts, selective coatings and other performance factors along with some futuristic aspects with respect to coatings and receiver inserts in view of high thermal performance.

Thermal selective coatings and its enhancement characteristics for efficient power generation through parabolic trough collector (PTC)

Analytical comparison of two distinct receiver tubes of a parabolic trough solar collector system for thermal application

This paper particularly aims to highlight the necessity of optimal geometrical design considerations of a parabolic trough collector (PTC)-mounted receiver tube in view of efficient operation and high-end performance. Many investigations, analysis, and validation have been done in this regard as solar energy-based PTC now a commercially mature technology acknowledges a variety of role in the form of power generation and other thermal applications. This article identifies the optimal rim angle corresponding to its tube size as required for high exergetic gains. Almost six receiver tubes, distinct in terms of dimensions and number of covers, are compared for their best results to be mounted on adequate geometry with different rim angle (40°, 80°, and 120°). A significant variation of flow rate (i.e., 16 to 216 L/h) and inlet fluid temperature (i.e., 323 K, 423 K, 523 K, 623 K, and 723 K) has been extensively detailed about high energy and exergy retrieval from the system. The study reports that all the favorable results are found with the receiver tube having a diameter of 0.027 m and a double envelope, compared to other design considerations. Results show that as the flow rate increases energy efficiency also increases up to some extent along with increasing receiver tube temperature. The highest energy and exergy efficiency are reported to be 79.4% and 45.9%, respectively, with 80° being the optimal rim angle for a 5.7-m-wide parabolic aperture. This article also takes care of levelized cost of energy of the proposed system, and it has been reported as 0.0372 $/KWh along with a payback period of 8.2 years.

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Thermal and geometrical assessment of parabolic trough collector-mounted double-evacuated receiver tube system

This paper aims to exploit the latent heat retrieval potential of the most commonly used refrigerants for optimal thermal management in PV modules, while operating under extremely hot conditions. PV/T system suffers from high thermal capacitive effects and is inadequate to regulate the module temperature close to ambient while operating under hot conditions and favourable irradiance. A dual expansion PV/T-driven heat pump is studied for optimal thermal management of the photovoltaic module with refrigerant R134a compared against R-32. A part of the refrigerant was condensed and sub-cooled to throttle it down to saturated liquid while raising the temperature of the saturated vapour refrigerant in a composite heat exchanger before feeding into the compressor. Another part undergoes an isentropic expansion, thereby reducing net work input to the cycle. The isentropic expander reduces the compressor work by 7.4 W and 6.72 W for the respective refrigerants. A finite time thermodynamic approach was adopted to validate for optimal evaporator temperature and overall heat transfer coefficient required to depict a feasible cycle. The evaporator temperature corresponding to the highest thermal exergy of the cycle was found to be 40 °C with 27.5 and 57.5 W m−2 K−1 being the requisite heat transfer coefficient. The proposed cycle with evaporator temperature maintained at 40 °C enables reasonable augmentation in the electrical response of the PV module while curbing the thermal mass and problem of reverse heating of the module.

Sahil Thappa

Papers

Futuristic decentralized clean energy networks in view of inclusive-economic growth and sustainable society

Thermal selective coatings and its enhancement characteristics for efficient power generation through parabolic trough collector (PTC)

Analytical comparison of two distinct receiver tubes of a parabolic trough solar collector system for thermal application

Thermal and geometrical assessment of parabolic trough collector-mounted double-evacuated receiver tube system

Numerical simulation and exergetic optimization of a PV/T integrated dual expansion heat pump