scholarly journals Analysis of Radiation Propagation inside a Hierarchical Solar Volumetric Absorber

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 27
Author(s):  
Luca Pratticò ◽  
Ruben Bartali ◽  
Luigi Crema ◽  
Enrico Sciubba
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Solar Power ◽  
Thermodynamic Cycle ◽  
Heat Transfer Fluid ◽  
Optical Behaviour ◽  
Concentrated Solar Power ◽  
Optical Efficiency ◽  
Radiation Propagation ◽  
Fluid Instability

The solar receiver is a critical component of concentrated solar power technology; it works as a heat exchanger, transforming the concentrated solar radiation into high-temperature heat. Volumetric receiver technologies, using air as a heat transfer fluid, are designed to reach higher temperatures than the current receiver technology, which is limited by material resistance and fluid instability. The higher temperature, up to 1200 K, could be used in high-temperature industrial processes or a high-temperature thermodynamic cycle. A correct radiation propagation is essential to develop their performances, reducing reflection and emission losses and promote the heat transfer to the fluid. In this study, the optical behaviour of a hierarchical volumetric receiver (HVR) developed in Bruno Kessler Foundation (FBK) has been studied using Monte Carlo ray tracing (MCRT) simulations. The simulations have been validated in an experimental setup that evaluates the light transmissivity of the HVR porous structure. Two different HVR structures are evaluated with MCRT simulations that use a real solar dish geometry to configure a complete concentrated solar power (CSP) plant. Results show that frontal and rear losses are, respectively, 12% and 3% of the incoming concentrated radiation. Inside the HVR, 15% of the incoming power is propagated trough the lateral void spaces. Therefore, the power spreading avoids the overconcentration of the centre of the focalized area. The HVR optical behaviour has been investigated, showing an optical efficiency of 85%.

scholarly journals Containment materials for liquid tin at 1350 °C as a heat transfer fluid for high temperature concentrated solar power

Solar Energy ◽  
2018 ◽  
Vol 164 ◽  
pp. 47-57 ◽  
Author(s):  
Yunshu Zhang ◽  
Ye Cai ◽  
SungHwan Hwang ◽  
Gregory Wilk ◽  
Freddy DeAngelis ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Solar Power ◽  
Heat Transfer Fluid ◽  
Concentrated Solar Power ◽  
Liquid Tin

scholarly journals A Definitive Model of a Small-Scale Concentrated Solar Power Hybrid Plant Using Air as Heat Transfer Fluid with a Thermal Storage Section and ORC Plants for Energy Recovery

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4741 ◽  
Author(s):  
Andrea Cinocca ◽  
Marco Di Bartolomeo ◽  
Roberto Cipollone ◽  
Roberto Carapellucci
Keyword(s):  
Heat Transfer ◽  
Solar Power ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Thermal Storage ◽  
Hybrid Plant ◽  
Heat Transfer Fluid ◽  
Electricity Production ◽  
Small Scale ◽  
Concentrated Solar Power

The aim of this work was to propose a small-scale Concentrated Solar Power plant using conventional technologies, in order to improve their flexibility and performances, and reinforce their competitiveness compared to traditional systems. Additionally, this study analyzed the possibility of providing continuity of energy production through an optimized hybrid system, which considered thermal energy storage from a gaseous Heat Transfer Fluid, air. It also considered the possibility of recovering part of the energy of the thermodynamic cycle through an Organic Rankine Cycle system with appropriate dimensions. The final outcomes were a 170 kW CSP plant with about 805 MWh of annual electricity production with a global solar capacity of 32.5%, about 900 kWh of thermal storage daily capacity, and an ORC recovery section of 54.2 kW with a specific production of 260 MWh/y.

High Temperature Thermochemical Heat Storage for Concentrated Solar Power Using Gas–Solid Reactions

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Franziska Schaube ◽  
Antje Wörner ◽  
Rainer Tamme
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Power Plants ◽  
Solar Power ◽  
Fixed Bed ◽  
Reaction System ◽  
Market Potential ◽  
Heat Of Reaction ◽  
Reactor Performance ◽  
Concentrated Solar Power

High temperature thermal storage technologies that can be easily integrated into future concentrated solar power plants are a key factor for increasing the market potential of solar power production. Storing thermal energy by reversible gas–solid reactions has the potential of achieving high storage densities while being adjustable to various plant configurations. In this paper the Ca(OH)2/CaO reaction system is investigated theoretically. It can achieve storage densities above 300 kWh/m3 while operating in a temperature range between 400 and 600°C. Reactor concepts with indirect and direct heat transfer are being evaluated. The low thermal conductivity of the fixed bed of solid reactants turned out to considerably limit the performance of a storage tank with indirect heat input through the reactor walls. A one-dimensional model for the storage reactor is established and solved with the Finite Element Method. The reactor concept with direct heat transfer by flowing the gaseous reactant plus additional inert gas through the solid reactants did not show any limitation due to heat transfer. If reaction kinetics are fast enough, the reactor performance in case of the Ca(OH)2/CaO reaction system is limited by the thermal capacity of the gaseous stream to take-up heat of reaction. However, to limit pressure drop and the according losses for compression of the gas stream, the size of the storage system is restricted in a fixed bed configuration.

Pilot-Scale System With Particle-Based Heat Transfer Fluids for Concentrated Solar Power Applications

2020 ◽  
Author(s):  
Christopher A. Bonino ◽  
Joshua Hlebak ◽  
Nicholas Baldasaro ◽  
Dennis Gilmore
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Heat Transfer Performance ◽  
High Efficiency ◽  
Solar Power ◽  
Critical Role ◽  
Heat Transfer Fluid ◽  
Process Unit ◽  
Transfer Performance ◽  
Concentrated Solar Power

Abstract Concentrated solar power (CSP) is a promising large-scale, renewable power generation and energy storage technology, yet limited by the material properties of the heat transfer fluid. Current CSP plants use molten salts, which degrade above 600°C and freeze below 220°C. A dry, particle-based heat transfer fluid (pHTF) can operate up to and above 1,000°C, enabling high-efficiency power cycles, which may enhance CSP’s commercial competitiveness. Demonstration of the flow and heat-transfer performance of the pHTF in a scalable process is thereby critical to assess the feasibility for this technology. In this study, we report on a first-of-a-kind pilot system to evaluate heat transfer to/from a densely flowing pHTF. This process unit circulates the pHTF at flowrates up to 1 tonne/h. Thermal energy is transferred to the pHTF as it flows through an electrically heated pipe. A fluidization gas in the heated zone enhances the wall-to-pHTF heat transfer rate. We found that the introduction of gas mixtures with thermal conductivities 4.6 times greater than that of air led to a 65% increase in the heat transfer coefficient compared to fluidization by air alone. In addition to the fluidization gas, the particle size also plays a critical role in heat transfer performance. Particles with an average diameter of 270 μm contributed to heat transfer coefficients that were up to 25% greater than the performance of other particles of the same composition in size range of 65 to 350 μm. The considerations for the design of an on-sun system are also discussed. Moreover, the collective work demonstrates the promise of this unique design in solar applications.

Analytical assessment of a concentrated solar sub-critical thermal power plant using low temperature heat transfer fluid

2020 ◽  
pp. 0958305X2092159
Author(s):  
Umish Srivastva ◽  
K Ravi Kumar ◽  
RK Malhotra ◽  
SC Kaushik
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
Thermal Efficiency ◽  
Thermal Power Plant ◽  
Solar Power ◽  
Thermal Power ◽  
Capital Cost ◽  
Shared Responsibility ◽  
Heat Transfer Fluid ◽  
Concentrated Solar Power

The paper presents energy–exergy–economic–environment–ethics analysis of a concentrated solar thermal power plant. Design basis of a concentrated solar power for 24 h operation on parabolic trough collector technology in best suited direct normal irradiation location and least capital cost analysis has been presented. An unconventional approach of reducing the capital cost is analyzed by intentionally designing the power plant for sub-critical conditions using a low-cost mineral oil with permissible operating temperature of 320°C in place of the conventional synthetic solar grade oil of 400°C. Using low pressure and temperature steam in the plant, it has been shown that while there is a reduction of 0.1% in energetic efficiency, there is a gain of 0.28% in the exergetic efficiency of the solar power plant conditions, gross thermal efficiency decreases by 1.18% and the net thermal efficiency decreases by 2.91%. However, the energetic and exergetic utilization factor for heat transfer fluid is increased by 0.84 and 5.58%, respectively. By suitably adjusting the solar field configuration and inlet oil temperature, energy savings to the tune of 45% is possible apart from 2.5 times of cost saving. An attempt has been made to quantifiably assess the ethics of switching to renewable electricity through shared responsibility as a novelty in the study. The payback period for the investment has also been shown to reduce from 20 years to 5 years assuming that the carbon price increases, concentrated solar power cost comes down by 25%, and cost at which electricity can be sold increases to US $0.14 (Rs. 10) per unit.

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