Heat Transfer Performances of Molten Salt in Spirally Grooved Solar Receiver Tube

2011 ◽  
Author(s):  
Jianfeng Lu ◽  
Xiangyang Shen ◽  
Jing Ding ◽  
Xiaoxi Yang
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Solar Receiver

Conceptual design of porous volumetric solar receiver using molten salt as heat transfer fluid

2021 ◽  
Vol 301 ◽  
pp. 117400
Author(s):  
Shen Du ◽  
Ming-Jia Li ◽  
Ya-Ling He ◽  
Sheng Shen
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Conceptual Design ◽  
Heat Transfer Fluid ◽  
Solar Receiver

Enhanced heat transfer in a parabolic trough solar receiver by inserting rods and using molten salt as heat transfer fluid

2018 ◽  
Vol 220 ◽  
pp. 337-350 ◽  
Author(s):  
Chun Chang ◽  
Adriano Sciacovelli ◽  
Zhiyong Wu ◽  
Xin Li ◽  
Yongliang Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Enhanced Heat Transfer ◽  
Solar Receiver

scholarly journals Heat transfer enhancement of a molten salt parabolic trough solar receiver with concentric and eccentric pipe inserts

2017 ◽  
Vol 142 ◽  
pp. 624-629 ◽  
Author(s):  
Chun Chang ◽  
Xiaodong Peng ◽  
Binjian Nie ◽  
Guanghui Leng ◽  
Chuan Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Parabolic Trough ◽  
Solar Receiver

Numerical Design of a Planar High-Flux Microchannel Solar Receiver

2014 ◽  
Author(s):  
Charles J. Rymal ◽  
Sourabh V. Apte ◽  
Vinod Narayanan ◽  
Kevin Drost
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Pressure Drop ◽  
Molten Salt ◽  
Thermal Stresses ◽  
Maximum Pressure ◽  
Operating Pressure ◽  
Design Features ◽  
Power Cycles ◽  
Solar Receiver

This paper discuses the design of several micro-channel solar receiver devices. Due to enhanced heat transfer in micro-channels, these devices can achieve a higher surface efficiency than current receiver technology, leading to an increase in overall plant efficiency. The goal is to design an efficient solar receiver based on use of super-critical carbon-dioxide and molten salt as heat-transfer fluids. The super-critical Brayton cycle has shown potential for a higher efficiency than current power cycles used in CSP. Molten salt has been used in CSP applications in the past. The required inlet and outlet temperatures of the fluid are 773.15 K and 923.15 K for carbon-dioxide and 573.15 K and 873.15 K for molten salt. These temperature values are determined by the power cycles the devices are designed to operate in. The required maximum pressure drop is 0.35 bar for carbon-dioxide and 1 bar for molten salt. These pressure values are intended to be a practical goal for maximum pressure drop. The super-critical carbon-dioxide power cycle requires an operating pressure of is 120 bar. Finally, each device must withstand any mechanical and thermal stresses that may exist. Devices presented range in size from 1 cm2 to 4 cm2 and in heat transfer rates from 200 W to 400 W. The size of the device is based on the output capacity of the solar simulator which will be used for testing. For carbon-dioxide, three designs were developed with varying manufacturability. The low risk design features machined and welded parts and straight parallel channels. The medium risk design features machined and diffusion bonded parts and straight parallel channels. The high risk design features a circular micro-pin-fin array created using EDM and is constructed using diffusion bonding. The absence of high operating pressure for molten salt made structural design much easier than for carbon-dioxide. Conjugate heat-transfer simulations of each design were used to evaluate pressure drop, receiver efficiency, and flow distribution. Two and three dimensional structural analyses were used to ensure that the devices would withstand the mechanical and thermal stresses. Based on the numerical analyses, a receiver efficiency of 89.7% with a pressure drop of 0.2 bar were achieved for carbon-dioxide. The design was found to have a structural safety factor of 1.3 based maximum mechanical stress occurring in the headers. For molten salt, an efficiency of 92.1% was achieved with a pressure drop of 0.5 bar.

Transient Three-Dimensional Heat Transfer Model of a Solar Thermochemical Reactor for H2O and CO2 Splitting via Nonstoichiometric Ceria Redox Cycling

2013 ◽  
Author(s):  
Justin Lapp ◽  
Wojciech Lipiński
Keyword(s):  
Heat Transfer ◽  
Heat Recovery ◽  
Fuel Efficiency ◽  
Three Dimensional ◽  
Reactor Design ◽  
Heat Transfer Model ◽  
Heat Fluxes ◽  
Transfer Model ◽  
Rotating Cylinders ◽  
Solar Receiver

A transient heat transfer model is developed for a solar reactor prototype for H2O and CO2 splitting via two-step non-stoichiometric ceria cycling. Counter-rotating cylinders of reactive and inert materials cycling between high and low temperature zones permit continuous operation and heat recovery. To guide the reactor design a transient three-dimensional heat transfer model is developed based on transient energy conservation, accounting for conduction, convection, radiation, and chemical reactions. The model domain includes the rotating cylinders, a solar receiver cavity, and insulated reactor body. Radiative heat transfer is analyzed using a combination of the Monte Carlo method, Rosseland diffusion approximation, and the net radiation method. Quasi-steady state distributions of temperatures, heat fluxes, and the non-stoichiometric coefficient are reported. Ceria cycles between temperatures of 1708 K and 1376 K. A heat recovery effectiveness of 28% and solar-to-fuel efficiency of 5.2% are predicted for an unoptimized reactor design.

Central Receiver System Solar Power Plant Using Molten Salt as Heat Transfer Fluid

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
J. Ignacio Ortega ◽  
J. Ignacio Burgaleta ◽  
Félix M. Téllez
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Molten Salt ◽  
Thermal Power ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Solar Thermal Power ◽  
Central Receiver ◽  
Spanish Legislation ◽  
Solar Thermal Power Generation

Of all the technologies being developed for solar thermal power generation, central receiver systems (CRSs) are able to work at the highest temperatures and to achieve higher efficiencies in electricity production. The combination of this concept and the choice of molten salts as the heat transfer fluid, in both the receiver and heat storage, enables solar collection to be decoupled from electricity generation better than water∕steam systems, yielding high capacity factors with solar-only or low hybridization ratios. These advantages, along with the benefits of Spanish legislation on solar energy, moved SENER to promote the 17MWe Solar TRES plant. It will be the first commercial CRS plant with molten-salt storage and will help consolidate this technology for future higher-capacity plants. This paper describes the basic concept developed in this demonstration project, reviewing the experience accumulated in the previous Solar TWO project, and present design innovations, as a consequence of the development work performed by SENER and CIEMAT and of the technical conditions imposed by Spanish legislation on solar thermal power generation.

Effect of Carbon Particle Feeding as Radiant Absorbent for Enhanced Heat Transfer

2021 ◽  
pp. 1-15
Author(s):  
Hamed Abedini ◽  
Nesrin Ozalp
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Temperature Profile ◽  
Energy Absorption ◽  
Carbon Particle ◽  
Carbon Particles ◽  
Solar Reactor ◽  
Simulation Results ◽  
Particle Feeding ◽  
Solar Receiver

Abstract Carbon particles can be used as catalyst in solar reactors where they serve as radiant absorbent and nucleation sites for the heterogeneous decomposition reaction. Unlike commonly used metal catalysts, carbon catalyst does not have durability problem and high cost. However, in order to achieve sustainable catalytic decomposition of feedstock over carbon catalysts at elevated temperatures, the surface area of the carbon particles must be maintained. A subsequent treatment of deactivated carbon samples with CO2 at about 1000 °C would increase the surface and would recover the original activity as catalyst. In a windowed solar reactor, carbon particles are directly exposed to the high flux irradiation providing efficient radiation heat transfer directly to the reaction site. Therefore, one of the key parameters to achieve higher conversion efficiencies in a solar reactor is the presence and transport of carbon particles. In this paper, a transient one-dimensional model is presented to describe effect of carbon particle feeding on energy transport and temperature profile of a cavity-type solar receiver. The model was developed by dividing the receiver into several control volumes and formulating energy balance equations for gas phase, particles, and cavity walls within each control volume. Monte Carlo ray tracing (MCRT) method was used to determine the solar heat absorbed by particles and cavity walls, as well as the radiative exchange between particles and cavity walls. Model accuracy was verified by experimental work using a solar receiver where carbon particles were injected uniformly. Comparison of simulation results with the experimentally measured temperatures at three different locations on cavity receiver wall showed an average deviation of 3.81%. The model was then used to study the effect of carbon particle size and feeding rate on the heat transfer, temperature profile, and energy absorption of the solar receiver. Based on the simulation results, it was found that injection of carbon particles with a size bigger than 500 µm has no significant influence on heat transfer of the system. However, by reducing the particle size lower than 500 µm, temperature uniformity and energy absorption were enhanced.

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