On-Sun Testing of a High Temperature Solar Receiver's Flux Distribution

2021 ◽  
pp. 1-24
Author(s):  
Samia Afrin ◽  
Nazmul Hossain ◽  
Zhiwen Ma ◽  
V M Krushnarao Kotteda ◽  
Antara Badhan ◽  
...  
Keyword(s):  
Renewable Energy ◽  
High Temperature ◽  
Flux Distribution ◽  
Receiver Design ◽  
The Novel ◽  
Ansys Fluent ◽  
Power Cycles ◽  
Cost Of Energy ◽  
Hexagonal Shape ◽  
Testing Facility

Abstract Concentrated solar power (CSP) is a promising technology in transitioning to renewable energy because of its abundance in nature and thermal energy storage capability. Among the four types of available CSP technology, including parabolic trough, linear Fresnel, power tower, and parabolic dishes, a power tower using a central receiver has more potential to generate high-temperature heat in a scale supporting power cycles efficiency and achieve low levelized cost of energy (LCOE). Other than the conventional type of receiver design, the high-absorptive receiver concept developed and presented in this paper is novel in its design approach. The novel receiver design originated from National Renewable Energy Laboratory (NREL) consists of an array of solar flux absorb tubes. The solar absorb tubes require uniform flux distribution and in-depth flux penetration through the three different reflective sections of tubes in a hexagonal shape. To evaluate this unique receiver design and thermal performance, the flux distribution, flux uniformity, and intensity were numerically simulated using ANSYS FLUENT and SolTrace modeling program. On-sun testing has been done at NREL high flux solar testing facility, based on the computational analysis.

scholarly journals Technology Pathways and Economic Analysis for Transforming High Temperature to Low Temperature District Heating Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Renewable Energy ◽  
High Temperature ◽  
Low Temperature ◽  
Economic Analysis ◽  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

There are 1454 district heating systems in Germany. Most of them are fossil based and with high temperature levels, which is neither efficient nor sustainable and needs to be changed for reaching the 2050 climate goals. In this paper, we present a case study for transforming a high to low temperature district heating system which is more suitable for renewable energy supply. With the Carnot Toolbox, a dynamic model of a potential district heating system is simulated and then transformed to a low temperature supply. A sensitivity analysis is carried out to see the system performance in case space constrains restrict the transformation. Finally, an economic comparison is performed. Results show that it is technically possible to perform the transformation until a very low temperature system. The use of decentralized renewable sources, decentralized heat storage tanks and the placement of a heat pump on each building are the key points to achieve the transformation. Regarding the sensitivity analysis, the transformation is worth doing until the seasonal storage and solar collector field sizes are reduced to 60% and 80% of their values in the reference case, respectively. The economic analysis shows, however, that it is hard for highly efficient low temperature renewable based heat networks to compete with district heating systems based on a centralized fossile CHP solution. Thus, though the presented transformation is technically possible, there is a strong need to change existing economic schemes and policies for fostering a stronger promotion of renewable energy policies in the heat sector.

Design of a New 45 kWe High-Flux Solar Simulator for High-Temperature Solar Thermal and Thermo-Chemical Research

2010 ◽  
Author(s):  
Katherine R. Krueger ◽  
Jane H. Davidson ◽  
Wojciech Lipin´ski
Keyword(s):  
High Temperature ◽  
Focal Plane ◽  
Flux Distribution ◽  
Solar Thermal ◽  
Optimized Design ◽  
High Flux ◽  
Chemical Research ◽  
Solar Simulator ◽  
Peak Flux ◽  
The Common

In this paper, we present a systematic procedure to design a solar simulator for high-temperature concentrated solar thermal and thermo-chemical research. The 45 kWe simulator consists of seven identical radiation units of common focus, each comprised of a 6.5 kWe xenon arc lamp close-coupled to a precision reflector in the shape of a truncated ellipsoid. The size and shape of each reflector is optimized by a Monte Carlo ray tracing analysis to achieve multiple design objectives, including high transfer efficiency of radiation from the lamps to the common focal plane and desired flux distribution. Based on the numerical results, the final optimized design will deliver 7.5 kW over a 6-cm diameter circular disc located in the focal plane, with a peak flux approaching 3.7 MW/m2.

Cyclic Methylsiloxanes as Working Fluids for Space Power Cycles

1993 ◽  
Vol 115 (3) ◽  
pp. 130-137 ◽  
Author(s):  
G. Angelino ◽  
C. Invernizzi
Keyword(s):  
High Temperature ◽  
Full Potential ◽  
Working Fluids ◽  
Power Cycles ◽  
Thermodynamic Performance ◽  
High Level ◽  
Organic Fluids ◽  
Large Wheel ◽  
Turbine Exhaust ◽  
Fast Rotating

The potential merits of cyclic polymethylsiloxanes, particularly those conventionally denominated D4 and D5, as working fluids for space power cycles are discussed. The attractive technical characteristics of these substances which are fully nontoxic, moderately flammable, and stable at high temperature are presented. Some experimental results on vapor pressure and on thermal stability are reported. A maximum operating temperature of about 400°C appears achievable. A comprehensive thermodynamic analysis comparing siloxanes with other classes of high temperature fluids is performed. The peculiar characters of siloxane cycles are found to be: a good overall efficiency achieved through a massive regeneration, a moderate expansion work, and an abundant volume flow at turbine exhaust. A number of two-stage turbines for two power levels (i.e., 30 and 5 kW) were designed using an appropriate optimization program. The resulting main features of such expanders were a satisfactory efficiency, a low rotating and peripheral speed, and a comparatively large wheel diameter. These characteristics seem of particular interest for low capacity systems where, with other fluids, turbines tend to be impractically small and fast rotating and where a high level of regeneration becomes more acceptable. In considering for the sake of comparison the thermodynamic performance of many classes of organic fluids, it becomes apparent that the full potential of organic power cycles in view of the variety of future needs has not yet been thoroughly investigated.

scholarly journals Environmental Impact and Levelised Cost of Energy Analysis of Solar Photovoltaic Systems in Selected Asia Pacific Region: A Cradle-to-Grave Approach

2021 ◽  
Vol 13 (1) ◽  
pp. 396
Author(s):  
Norasikin Ahmad Ludin ◽  
Nurfarhana Alyssa Ahmad Affandi ◽  
Kathleen Purvis-Roberts ◽  
Azah Ahmad ◽  
Mohd Adib Ibrahim ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Renewable Energy ◽  
Life Cycle ◽  
Environmental Impact ◽  
Degradation Rate ◽  
Economic Feasibility ◽  
Asia Pacific ◽  
Solar Photovoltaic ◽  
Economic Output ◽  
Cost Of Energy

Sustainability has been greatly impacted by the reality of budgets and available resources as a targeted range of carbon emission reduction greatly increases due to climate change. This study analyses the technical and economic feasibility for three types of solar photovoltaic (PV) renewable energy (RE) systems; (i) solar stand-alone, a non-grid-connected building rooftop-mounted structure, (ii) solar rooftop, a grid-connected building rooftop-mounted structure, (iii) solar farm, a grid-connected land-mounted structure in three tropical climate regions. Technical scientific and economic tools, including life cycle assessment (LCA) and life cycle cost assessment (LCCA) with an integrated framework from a Malaysian case study were applied to similar climatic regions, Thailand, and Indonesia. The short-term, future scaled-up scenario was defined using a proxy technology and estimated data. Environmental locations for this scenario were identified, the environmental impacts were compared, and the techno-economic output were analysed. The scope of this study is cradle-to-grave. Levelised cost of energy (LCOE) was greatly affected due to PV performance degradation rate, especially the critical shading issues for large-scale installations. Despite the land use impact, increased CO2 emissions accumulate over time with regard to energy mix of the country, which requires the need for long-term procurement of both carbon and investment return. With regards to profitably, grid-connected roof-mounted systems achieve the lowest LCOE as compared to other types of installation, ranging from 0.0491 USD/kWh to 0.0605 USD/kWh under a 6% discounted rate. A simple payback (SPB) time between 7–10 years on average depends on annual power generated by the system with estimated energy payback of 0.40–0.55 years for common polycrystalline photovoltaic technology. Thus, maintaining the whole system by ensuring a low degradation rate of 0.2% over a long period of time is essential to generate benefits for both investors and the environment. Emerging technologies are progressing at an exponential rate in order to fill the gap of establishing renewable energy as an attractive business plan. Life cycle assessment is considered an excellent tool to assess the environmental impact of renewable energy.

Computation of Thermodynamic Properties of Carbon Dioxide in the Range 0–750 Deg C

1970 ◽  
Vol 92 (3) ◽  
pp. 301-309 ◽  
Author(s):  
G. Angelino ◽  
E. Macchi
Keyword(s):  
Carbon Dioxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Critical Region ◽  
Density Measurement ◽  
Working Fluid ◽  
Power Cycles ◽  
Wide Range

The computation of power cycles employing carbon dioxide as working fluid and extending down to the critical region requires the knowledge of the thermodynamic properties of CO2 within a wide range of pressures and temperatures. Available data are recognized to be insufficient or insufficiently accurate chiefly in the vicinity of the critical dome. Newly published density and specific heat measurements are employed to compute thermodynamic functions at temperatures between 0 and 50 deg C, where the need of better data is more urgent. Methods for the computation of thermal properties from density measurement in the low and in the high temperature range are presented and discussed. Results are reported of the computation of entropy and enthalpy of CO2 in the range 150–750 deg C and 40–600 atm. The probable precision of the tables is inferred from an error analysis based on the generation, by means of a computer program of a set of pseudoexperimental points which, treated as actual measurements, yield useful information about the accuracy of the calculation procedure.

scholarly journals QUANTIFYING THE UNCERTAINTY OF SOLAR PHOTOVOLTAIC SOFT COSTS IN THE “COST OF RENEWABLE ENERGY SPREADSHEET TOOL” (CREST) MODEL

2020 ◽  
Vol 1 ◽  
pp. 2157-2166
Author(s):  
S. M. Syal ◽  
E. F. MacDonald
Keyword(s):  
Renewable Energy ◽  
Development Process ◽  
Solar Photovoltaic ◽  
Financial Barriers ◽  
Solar Photovoltaics ◽  
Cost Of Energy ◽  
Sensitivity Indices ◽  
Project Costs ◽  
The Cost ◽  
Total Project

AbstractWhile solar photovoltaics are projected to grow, major financial barriers exist that impede installation. Soft costs (human-driven costs) can account for over half of total project costs and are often simplified in typical models. We use the National Renewable Energy Laboratory's “Cost of Renewable Energy Spreadsheet Tool” to quantify uncertainty of three soft cost inputs and their influence on the output cost of energy using variance-based sensitivity indices. We then suggest how the development process and model can be redesigned to represent the complexities of this socio-technical system.

scholarly journals Sodium receiver designs for integration with high temperature power cycles

Energy ◽  
2019 ◽  
Vol 187 ◽  
pp. 115994 ◽  
Author(s):  
Tim Conroy ◽  
Maurice N. Collins ◽  
Ronan Grimes
Keyword(s):  
High Temperature ◽  
Power Cycles
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