Techno-Economic Analysis of Dual-Stage Sodium Thermal Electrochemical Converter (Na-TEC) Power Block for Distributed CSP

2018 ◽  
Author(s):  
Andrey Gunawan ◽  
Alexander Limia ◽  
Jong Min Ha ◽  
Peter A. Kottke ◽  
Seung Woo Lee ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Material Selection ◽  
Single Stage ◽  
Design System ◽  
Small Scale ◽  
Scaling Analysis ◽  
Isothermal Expansion ◽  
Power Block ◽  
Dual Stage ◽  
Cost Scaling

A sodium thermal electrochemical converter (Na-TEC) converts heat directly into electricity without moving parts by isothermal expansion of ions through beta”-alumina solid-electrolyte (BASE). These generators are most similar to thermoelectric generators; however, they are considerably more efficient than the best performing thermoelectric materials. While these heat engines have been considered for CSP applications, literature review found that the efficiency of single-stage Na-TEC could readily achieve 20% even though ideal cycle efficiencies predict above 45% efficiency at elevated temperatures. Thermal parasitic loss has been identified to be responsible for the largest drop in the efficiency. Our recent study shows that staging helps to improve thermal management of the Na-TEC, due to the lower average temperature of the device, which can reduce the thermal parasitic loss. We demonstrate that dual-stage device can improve the efficiency by up to 8% over the best performing single-stage device. We are currently designing and developing a modular dual-stage Na-TEC power block with target efficiency of 33%. We emphasize modularity because this power block can be potentially deployed for both small-scale dish solar, which is appropriate for distributed residential scale (2–3 kWe), and large-scale heliostats and parabolic trough CSP, which is appropriate for centralized industrial scale. A fundamental cost-scaling relationship for this technology was developed based on this design. System variables and component manufacturing methods with material selection for processes were established. The current off-the-shelf component costs indicated an overnight capital cost of $2,044/kWe. The costs of BASE, manufacturing, and electrode preparation have driven the overall price of the module. The paper demonstrates $/W design optimization and cost scaling analysis to reduce the system capital $/W metric below $ 1,500/kWe, with the goal being to achieve the cost target of <900/kWe set by Department of Energy’s Sun Shot Initiative.

Probing the Small-Scale Plasticity of an Icosahedral Quasicrystal I-Al-Pd-Mn at Elevated Temperatures

2020 ◽  
Author(s):  
Changjun Cheng ◽  
Yuan Xiao ◽  
Michel J.R. Haché ◽  
Zhiying Liu ◽  
Alla S. Sologubenko ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Small Scale ◽  
Icosahedral Quasicrystal

scholarly journals Formation conditions and mechanical properties of aggregates produced in tephra–water–snow flows

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Hirofumi Niiya ◽  
Kenichi Oda ◽  
Daisuke Tsuji ◽  
Hiroaki Katsuragi
Keyword(s):  
Mechanical Properties ◽  
Mixing Time ◽  
Testing Machine ◽  
Small Scale ◽  
Scaling Analysis ◽  
Compression Tests ◽  
Ice Slurry ◽  
Experimental Conditions ◽  
Formation Conditions ◽  
Snow And Ice

Abstract The formation of aggregates consisting of snow, water, and tephra has been reported in small-scale experiments on three-phase flows containing tephra, water, and snow, representing lahars triggered by snowmelt. Such aggregates reduce the mobility of mud flow. However, the formation mechanism of such aggregates under various conditions has not been investigated. To elucidate the formation conditions and mechanical properties of the aggregates, we performed mixing experiments with materials on a rotating table and compression tests on the resulting aggregates with a universal testing machine in a low-temperature room at $$0\,^{\circ }\text {C}$$ 0 ∘ C . From experiments with varying component ratios of the mixture and tephra diameter, the following results were obtained: (i) the aggregate grew rapidly and reached maturity after a mixing time of 5 min; (ii) the mass of aggregates increased with snow concentration, exhibiting an approximately linear relationship; (iii) single aggregates with large mass formed at lower and higher tephra concentrations, whereas multiple aggregates with smaller mass were observed at intermediate concentrations; (iv) the shape of the aggregate satisfied the similarity law for an ellipsoid; (v) the compressive mechanical behavior could be modeled by an empirical nonlinear model. The obtained mechanical properties of the aggregates were independent of the experimental conditions; (vi) scaling analysis based on the Reynolds number and the strength of the aggregates showed that the aggregates cannot form in ice-slurry lahars. Our findings suggest that low-speed lahars containing snow and ice are likely to generate aggregates, but snow and ice in the ice-slurry lahars are dispersed without such aggregates.

scholarly journals 2D Nanomaterials for Effective Energy Scavenging

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Md Al Mahadi Hasan ◽  
Yuanhao Wang ◽  
Chris R. Bowen ◽  
Ya Yang
Keyword(s):  
Large Scale ◽  
Waste Heat ◽  
Material Selection ◽  
Power Supplies ◽  
Small Scale ◽  
Energy Scavenging ◽  
Power Sources ◽  
Practical Applications ◽  
2D Nanomaterials ◽  
Self Powered

AbstractThe development of a nation is deeply related to its energy consumption. 2D nanomaterials have become a spotlight for energy harvesting applications from the small-scale of low-power electronics to a large-scale for industry-level applications, such as self-powered sensor devices, environmental monitoring, and large-scale power generation. Scientists from around the world are working to utilize their engrossing properties to overcome the challenges in material selection and fabrication technologies for compact energy scavenging devices to replace batteries and traditional power sources. In this review, the variety of techniques for scavenging energies from sustainable sources such as solar, air, waste heat, and surrounding mechanical forces are discussed that exploit the fascinating properties of 2D nanomaterials. In addition, practical applications of these fabricated power generating devices and their performance as an alternative to conventional power supplies are discussed with the future pertinence to solve the energy problems in various fields and applications.

Structural Post-Fire Behaviour of the Steel I-Shape Beams-to-Cylindrical Columns

2012 ◽  
Vol 249-250 ◽  
pp. 1057-1062
Author(s):  
M. Zeinoddini ◽  
S.A. Hosseini ◽  
M. Daghigh ◽  
S. Arnavaz
Keyword(s):  
Structural Damage ◽  
Elevated Temperatures ◽  
Small Scale ◽  
Fire Tests ◽  
Fire Behaviour ◽  
Fire Event ◽  
Rescue Workers ◽  
Left Behind ◽  
Oil Platforms ◽  
In Fire

Previous researchers have tried to predict the response of different types of structures under elevated temperatures. The results are important in preventing the collapse of buildings in fire. Post-fire status of the structures is also of interest for ensuring the safety of rescue workers during the fire and in the post-fire situations. Determining the extent of the structural damage left behind a fire event is necessary to draw up adequate repair plans. Connections play an important role on the fire performance of different structures. Due to the high cost of fire tests, adequate experimental data about a broad range of connections is not available. A vulnerable type of such connections to fire is the weld connections between I-shape beams and cylindrical columns in oil platform topsides. Considering the high probability of fire in oil platforms, study of the behaviour of these connections at elevated temperatures and in the post-fire, is of great importance. In the current study, eight small scale experimental fire tests on welded connections between I-shape beams and cylindrical columns have been conducted. Four tests are aimed at investigating the structural performance of this connection at elevated temperature. In other tests, post-fire behaviour of these connections has been studied to investigate their residual structural strength.

An analytical model for the behavior of I-shaped beam to cylindrical column connections at room temperature and high temperatures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Seied Ahmad Hosseini ◽  
Mostafa Zeinoddini
Keyword(s):  
Analytical Solution ◽  
Elevated Temperatures ◽  
Element Model ◽  
Small Scale ◽  
Offshore Platforms ◽  
Rotational Stiffness ◽  
Rotation Curves ◽  
Content Type ◽  
Shaped Beam ◽  
Cylindrical Column

PurposeIn this paper, a closed-form analytical solution for the prediction of moment-rotation and the rotational stiffness-rotation curves of I-shaped beam to cylindrical column connections, commonly used on offshore platforms, at room and elevated temperatures, are presented.Design/methodology/approachAn analytical solution for the prediction of moment-rotation and the rotational stiffness-rotation curves of I-shaped beam to cylindrical column connections is presented. The results of this model are compared with those of a non-linear coupled mechanical-thermal finite element model and small-scale experimental tests previously provided by the authors.FindingsIn this paper, a closed-form analytical solution for the prediction of moment-rotation and the rotational stiffness-rotation curves of I-shaped beam to cylindrical column connections, commonly used on offshore platforms, at room and elevated temperatures, is presented. The required yield and plastic moments in this model are provided as an extension to Roark's relationships. The results of this model are compared with those of a non-linear coupled mechanical-thermal finite element model and small-scale experimental tests previously provided by the authors. A reasonable agreement has been found between the analytical model results and the experimental/numerical modeling results.Originality/valueThis article is extracted from the author’s doctoral thesis, and all its achievements belong to the authors of the article.

Single vs. Dual Stage Actuators: Why and When

2002 ◽  
Author(s):  
Fu-Ying Huang ◽  
Tetsuo Semba ◽  
Matthew White
Keyword(s):  
System Dynamics ◽  
Single Stage ◽  
Actuator Dynamics ◽  
Dual Stage ◽  
Dual Stage Actuator

Higher TPI HDD requires lower disturbance and higher error rejection capability. One of the limitations to achieve high error rejection capability is the dynamics of the actuator. Dual stage actuator (DSA) has been considered to replace single stage actuator (SSA) someday because of system dynamics difference and more freedom in servo design that may avoid the constraint of single stage actuator dynamics on servo. SSA and DSA were compared based on their dynamics, servo designs, and TMR benefits. The extendibility and limitations of both systems were studied. The criteria on when DSA would be implemented are also discussed.

Reliability Study of Reference Semiconductor Encapsulation Materials for Biocompatible Packaging

2012 ◽  
Vol 2012 (1) ◽  
pp. 000148-000153
Author(s):  
Karl Malachowski ◽  
Karen Qian ◽  
Maaike Op de Beeck ◽  
Rita Verbeeck ◽  
George Bryce ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Process Integration ◽  
Material Selection ◽  
Semiconductor Industry ◽  
Electrical Performance ◽  
Integration Scheme ◽  
Back Side ◽  
Wafer Level ◽  
Nitride Layers

Material selection is the key issue when developing a biocompatible packaging process for implantable electronic systems. To secure a reliable performance of the chip in such a package, its encapsulation has to be considered up-front in the wafer-level integration scheme. A differentiation of two main material types can be made:1) Insulating or passive materials functioning as a bi-directional diffusion barrier preventing body fluids leaking into the package causing systems malfunction due to possible materials corrosion and also avoiding a leakage of built-in materials to the in-vivo environment and2) Conductive or active materials as diffusion barriers, e.g. against copper diffusion or as direct external contacts responsible for electrical performance of the system. This study investigates the properties of two widely used insulating materials in the semiconductor industry, the nitride and the oxide. Both material types are deposited in a PECVD system using different temperatures; 400 ° C for CMOS compatibility and 200 ° C for wafer back side process integration when a temporary carrier system is used. The biocompatibility investigations of these materials (evaluated using cell lines and primary cells) show promising results. However, for the long term application, the stability results for the oxide layers show hydration effects resulting in material degradation where the nitride layers clearly show corrosion and are even etched when elevated temperatures are applied. This fact is surprising since nitride layers are widely used as a humidity barrier for various chip types but obviously not suitable for a direct contact with liquids. Various analysis methods using e.g. Fourier Transformed IR Spectroscopy or mass measurements substantiate this thesis.

Transfer Molding Technology for Smart Power Electronics Modules: Materials and Processes

2012 ◽  
Vol 9 (2) ◽  
pp. 78-86 ◽  
Author(s):  
K.-F. Becker ◽  
D. Joklitschke ◽  
T. Braun ◽  
M. Koch ◽  
T. Thomas ◽  
...  
Keyword(s):  
Power Electronics ◽  
Elevated Temperatures ◽  
Material Selection ◽  
Thermal Contact ◽  
Industrial Applications ◽  
Thermomechanical Properties ◽  
Discrete Control ◽  
Lead Frame ◽  
Control Logic ◽  
Transfer Molding

In recent years, within power electronics packaging, there has been a trend toward compact power electronics modules for automotive and industrial applications, where a smart integrated control unit for motor drives is replacing bulky substrates with discrete control logic and power electronics. Most recent modules combine control and power electronics, yielding maximum miniaturization. Transfer molding is the method of choice for cost-effective encapsulation of such modules due to robustness of the molded modules and moderate cost of packaging. But there are challenges with this type of package. Typically, these packages are asymmetric, and thus a substrate with single sided assembly is overmolded on the component side and the substrate backside is exposed, providing a heat path for optimized cooling. This asymmetric geometry is prone to yielding warped substrates, preventing optimum thermal contact to the heat sink and also putting thermomechanical stress on the encapsulated components, possibly reducing reliability. Such packages are truly heterogeneous, combining power ICs, wire bonds, SMDs, control ICs, substrate, and lead frame surfaces. As a result, the encapsulant used needs to adhere sufficiently to all surfaces present. Additionally, those packages need to operate at elevated temperatures for extended time periods, for example, at 150°C for 2000 h and more, so high thermal stability is of prime importance. Within this paper, a reference application is described integrating power and control logic inside a lead frame based molded package. Taking into account the challenges mentioned above, a detailed description of material selection for this module will be given, including material analysis, such as rheology, reactivity, and change in εr; and thermomechanical properties, in initial stage as f(t,T) and after media storage. Process development tools for module molding are used to ensure manufacturability and usability. Concluding rules for encapsulant material selection and package setup are provided.

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