High Temperature Solar Linear Receiver Enclosed in a Reflecting Elliptic Cavity

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Roberto Grena ◽  
Michela Lanchi ◽  
Luca Turchetti ◽  
Tommaso Crescenzi
Keyword(s):  
High Temperature ◽  
Thermal Emission ◽  
Surface Films ◽  
Fluid Temperature ◽  
Fuel Production ◽  
Optical Efficiency ◽  
Thermochemical Cycles ◽  
Linear Receiver ◽  
Elliptic Cavity ◽  
Thermal Simulations

Abstract A linear receiver able to achieve temperatures up to 800 °C is presented. The high-temperature resistance is achieved by avoiding critical aspects (vacuum, glass-metal joints, surface films) that limit the temperature in usual receivers; the thermal insulation is obtained by enclosing the receiver tube in an elliptic reflecting cavity. The tube is placed near a focus of the cavity, and the primary collector concentrates the radiation on the other focus, where the cavity has a small opening: the ellipse reflects the radiation toward the tube and largely contains the reflected radiation and thermal emission, thus acting both as a secondary reflector and as a cavity receiver. Optical and thermal simulations show that temperatures up to 800 °C can be achieved, with optical efficiency above 70% and thermal efficiency in the range 45–85% for temperatures in the range 500–800 °C; the local overall efficiency ranges from about 40% to 66%, depending on the receiver tube emissivity and fluid temperature. In this way, the field of applicability of the linear collector technology can be significantly extended to include a vast amount of processes such as thermochemical cycles for hydrogen production, and solar fuel production processes, which require temperatures above 700 °C.

Preliminary Techno-Economic Optimization Of 1.3 MWe Particle Heating Receiver Based CSP Power Tower Plant for the MENA Region

2021 ◽  
Author(s):  
Shakir Shakoor Khatti ◽  
Sheldon Jeter ◽  
Hany Al-Ansary
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Energy Demand ◽  
Cost Models ◽  
Low Carbon ◽  
Manufacturing Companies ◽  
Mena Region ◽  
Optical Efficiency ◽  
Central Receiver ◽  
Particle Heating

Abstract Due to increasing energy demand around the globe and potential environmental impacts of fossil fuels, it has become a crucial task for researchers to find alternatives to generate electricity from low-carbon resources at lower costs. Three types of advanced CSP are under consideration: systems heating salt, gas, or particulate. Particle heating receiver (PHR) based central receiver power tower CSP is an emerging technology that promises higher operating temperatures and more cost-effective thermal energy storage (TES) than feasible with existing or alternative CSP systems. For reasons stated above and others, we propose that the particle heating receiver (PHR) based CSP in the classic central receiver power tower (CRPT) configuration will be the most suitable especially in the promising Middle East and North Africa (MENA) region. Specifically, Duba, Al Wajih, and Wa’ad Al-Shamaal regions in Saudi Arabia have high direct normal irradiation (DNI) and represent potential locations. PHR based CSP power tower plant consists of a central receiver power tower with TES and cavity receiver, heliost at field, a high-temperature solar gas turbine with built-in fuel backup to operate in hybrid mode (using both fuel and solar-thermal resources). This study focuses on the optimization of a solar heat supply system (SHSS), consisting of a tower, cavity receiver, and heliostat field. SolarPILOT – Solar Power tower Integrated Layout and Optimization Tool is a field layout optimization tool developed by National Renewable Energy Laboratory (NREL). SolarPILOT is used in this study to generate the field layout of a 1.3 MWe power plant with a solar multiple (SM) of 2, 3, and 4. Cost models for the tower, receiver, and heliostats are developed using the data from research programs, contractors, manufacturing companies, and general cost engineering data and tools. System Advisor Model (SAM) is further used to simulate the annual performance of CSP tower plant including power block (high-temperature gas turbine) and TES using optical efficiency data from SolarPILOT to optimize PHR-based CSP tower plant. The results of this research are fundamental to the techno-economic analysis (TEA) of this and similar smaller-scale systems and will support the TEA of larger grid-connected and smaller off-grid systems operating independently or in conjunction with PV systems.

Effect of Drilling Fluid Temperature on Formation Fracture Pressure Gradient

2021 ◽  
Author(s):  
Ahmed Mostafa Samak ◽  
Abdelalim Hashem Elsayed
Keyword(s):  
High Temperature ◽  
Pressure Gradient ◽  
Thermal Effect ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Cooling Effect ◽  
Fluid Temperature ◽  
Lost Circulation ◽  
Fracture Pressure ◽  
Downhole Temperature

Abstract During drilling oil, gas, or geothermal wells, the temperature difference between the formation and the drilling fluid will cause a temperature change around the borehole, which will influence the wellbore stresses. This effect on the stresses tends to cause wellbore instability in high temperature formations, which may lead to some problems such as formation break down, loss of circulation, and untrue kick. In this research, a numerical model is presented to simulate downhole temperature changes during circulation then simulate its effect on fracture pressure gradient based on thermo-poro-elasticity theory. This paper also describes an incident occurred during drilling a well in Gulf of Suez and the observations made during this incident. It also gives an analysis of these observations which led to a reasonable explanation of the cause of this incident. This paper shows that the fracture pressure decreases as the temperature of wellbore decreases, and vice versa. The research results could help in determining the suitable drilling fluid density in high-temperature wells. It also could help in understanding loss and gain phenomena in HT wells which may happen due to thermal effect. The thermal effect should be taken into consideration while preparing wellbore stability studies and choosing mud weight of deep wells, HPHT wells, deep water wells, or wells with depleted zones at high depths because cooling effect reduces the wellbore stresses and effective FG. Understanding and controlling cooling effect could help in controlling the reduction in effective FG and so avoid lost circulation and additional unnecessary casing points.

scholarly journals Use of waste material mixtures for energy purposes in small combustion devices

2014 ◽  
Vol 60 (No. 2) ◽  
pp. 50-59 ◽  
Author(s):  
J. Malaťák ◽  
J. Bradna
Keyword(s):  
Carbon Monoxide ◽  
High Temperature ◽  
Nitrogen Oxides ◽  
Energy Use ◽  
Thermal Emission ◽  
Hot Water ◽  
Coal Sludge ◽  
Solid Biofuels ◽  
Increasing Trend ◽  
Emission Limits

The article assesses the energy use of solid biofuels (wheat and rape straw) and their blends with suitable additives (cocoa husks, brown coal and coal sludge). The elemental and stoichiometric analysis evaluates their suitability for energy recovery. Furthermore, thermal emission characteristics in automatic hot water boiler VERNER A251 are observed. The results of thermal emission measurements show that all samples meet the requirements of the Directive No. 13/2006 for carbon monoxide (2,000 mg/m<sup>3</sup>). The average nitrogen oxides emission concentrations exceed emission limits compared with the Directive No. 13/2006 (250 mg/m<sup>3</sup>) for all samples of solid biofuels. One reason is the high temperature in the combustion chamber that increases combustion temperature and results in high temperature of nitrogen oxides. Another problem is carbon monoxide that depends on the coefficient of excess air. The value of this coefficient drops under its optimum (2.5) and subsequently follows an increasing trend. &nbsp;

scholarly journals First demonstration of direct hydrocarbon fuel production from water and carbon dioxide by solar-driven thermochemical cycles using rhodium–ceria

2016 ◽  
Vol 9 (7) ◽  
pp. 2400-2409 ◽  
Author(s):  
Fangjian Lin ◽  
Matthäus Rothensteiner ◽  
Ivo Alxneit ◽  
Jeroen A. van Bokhoven ◽  
Alexander Wokaun
Keyword(s):  
Carbon Dioxide ◽  
Hydrocarbon Fuel ◽  
Fuel Production ◽  
Thermochemical Cycles ◽  
First Time

Sustained production of methane directly from water and carbon dioxide by solar-driven thermochemical cycles is achieved for the first time with rhodium on ceria.

Design Challenge of Rigid Riser-Spool Piece Against HTHP Induced Expansion in Pipe-in-Pipe Systems

2014 ◽  
Author(s):  
Facheng Wang ◽  
Ming Gao ◽  
Jun Wang ◽  
Yigong Zhang ◽  
Xu Jia ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Energy Demand ◽  
Bohai Sea ◽  
Oil And Gas ◽  
Mainland China ◽  
Structural Complexity ◽  
Calculation Model ◽  
Fluid Temperature ◽  
Gas Reservoirs

Developments of oil and gas reservoirs in Bohai Sea, South China Sea etc., are presently accelerated, to cope with the significant increase in energy demand from the mainland, China. In recent developments in Bohai Sea, fluid temperature and pressure have been found dramatically being increased up to 100 °C and 20 MPa respectively. The fact that High Temperature and High Pressure (HTHP) in Bohai area brings design challenges, especially to jacket risers and spool pieces. Pipe-in-Pipe (PIP) flowline systems have been widely employed in this region and are continuously being considered for further developments. This is due to its significant thermal insulation capacity to deal with the High Temperature and High Pressure (HTHP) issue. To cope with the challenges induced by HPHT and structural complexity of PIP, COTEC Offshore Engineering Solutions, together with its mother company, China Offshore Oil Engineering Company, have developed a approach by using ABAQUS and AutoPIPE. This paper describes the relevant experience obtained during one development in Bohai Sea, BZ34-2/4 project containing dozens of risers and spool pieces. Two main parts are presented. Firstly, a beam-element based expansion calculation model adopting ABAQUS has been developed to achieve accurate HPHT induced expansions. The structural behavior of PIP can be represented in the developed model, meanwhile with minimum increase in modeling complexity. Secondly, practical and extensive parametric studies have been carried on the riser and spool flexibility against HPHT induced expansions. Since Bohai Sea has been developed extensively, many risers are post-installed and the existing of restriction areas practically enlarges the difficulties of anchor clamp and spool arrangements. Key parameters of these arrangements, such as Z/L shape, the length between two bends, the combinations of bend angles, the length of protection pipe on the riser etc. have been comprehensively investigated. “Gold” rules for rigid riser accessories arrangements and spool piece layout have been suggested accordingly.

Performance of a 100 kWth Concentrated Solar Beam-Down Optical Experiment

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Marwan Mokhtar ◽  
Steven A. Meyers ◽  
Peter R. Armstrong ◽  
Matteo Chiesa
Keyword(s):  
Flux Distribution ◽  
Thermal Flux ◽  
Heat Transfer Fluid ◽  
Distribution Data ◽  
Fluid Temperature ◽  
Aperture Size ◽  
Optical Efficiency ◽  
Optimal Receiver ◽  
Daily Average ◽  
Optical Experiment

An analysis of the beam down optical experiment (BDOE) performance with full concentration is presented. The analysis is based on radiation flux distribution data taken on Mar. 21st, 2011 using an optical-thermal flux measurement system. A hypothetical thermal receiver design is used in conjunction with the experimental data to determine the optimal receiver aperture size as a function of receiver losses and flux distribution. The overall output of the plant is calculated for various operating temperatures and three different control strategies namely, constant mass flow of the heat transfer fluid (HTF), constant outlet fluid temperature and real-time optimal outlet fluid temperature. It was found that the optimal receiver aperture size (radius) of the receiver ranged between (1.06 and 1.71 m) depending on temperature. The optical efficiency of the BDOE ranged from 32% to 37% as a daily average (average over the ten sunshine hours). The daily average mean flux density ranged between 9.422 kW/m2 for the 1.71 m-receiver and 20.9 kW/m2 for the 1.06 m-receiver. Depending on the control parameters and assuming an open receiver with solar absorptivity of 0.95 and longwave emissivity of 0.10. The average receiver efficiency varied from 71% at 300 °C down to 68% at 600 °C. The overall daily average thermal efficiency of the plant was between 28% and 24%, respectively for the aforementioned temperatures. The peak of useful power collected in the HTF was around 105 kWth at 300 °C mean fluid temperature and 89 kWth at 600 °C.

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