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This paper presents experimental results of the impact of CO(2) co-feed on a gasification/pyrolysis process for various feedstocks (biomass, coal, and municipal solid waste (MSW)). Various feedstocks were thermo-gravimetrically characterized under various atmospheric conditions and heating rates. A substantial amount of char burn out was identified in the presence of CO(2) via a series of thermo-gravimetric analysis tests, which enabled high conversion of final mass (approximately 99%) to be achieved. The impact of CO(2) co-feed on the volatilization regime during the pyrolysis/gasification process was not apparent at a heating rate of 10-40 degrees C min(-1). However, the impact of CO(2) on the volatilization regime at a fast heating rate (950 degrees C min(-1)) was substantial. For example, significant enhancement in the generation of CO, by a factor of approximately 2, was observed in the presence of CO(2). The generation of major chemical species, such as CH(4) and C(2)H(4), were enhanced, but this was not as apparent as in the case with CO. In addition, introducing CO(2) to the pyrolysis/gasification process enabled the amount of condensable liquid hydrocarbons, such as tar (approximately 30-40%) to be significantly reduced in the presence of CO(2), in that injecting CO(2) into the pyrolysis/gasification process expedites cracking the volatilized chemical species. Experimental work confirmed that biomass and MSW could be feasible and desirable feedstocks for the pyrolysis/gasification process as these feedstocks can be easily treated compared to coal. To extend this understanding to a more practical level, various feedstocks were tested in a tubular reactor and drop tube reactor under various experimental conditions.

The many advantages of slug flow pneumatic conveying are outweighed by the lack of understanding of the flow mechanisms. For horizontal slug flow, the unique feature is the stationary layer of material found between the travelling slugs, which was recently shown to be characterised by two constants. This paper looks to utilise the vast data available in the literature, which is representative of the entire mode of flow, and relates the stationary layer and slug velocity to predict the two constants from only these inputs. It was found that, even for the vast range of materials and systems considered, slug flow encompasses a narrow bound of the two constants. Furthermore, an empirical approach that was developed to relate the layer fraction and particle velocity was found to provide good agreement to measurements and may be of use in other investigations that require an additional equation for modelling.

Abstractπ‐Conjugated polyelectrolytes (CPEs) have been studied as interlayers on top of a separate hole transport layer (HTL) to improve the wetting, interfacial defect passivation, and crystal growth of perovskites. However, very few CPE‐based HTLs have been reported without rational molecular design as ideal HTLs for perovskite solar cells (PeSCs). In this study, the authors synthesize a triphenylamine‐based anionic CPE (TPAFS‐TMA) as an HTL for p‐i‐n‐type PeSCs. TPAFS‐TMA has appropriate frontier molecular orbital (FMO) levels similar to those of the commonly used poly(bis(4‐phenyl)‐2,4,6‐trimethylphenylamine) (PTAA) HTL. The ionic and semiconducting TPAFS‐TMA shows high compatibility, high transmittance, appropriate FMO energy levels for hole extraction and electron blocking, as well as defect passivating properties, which are confirmed using various optical and electrical analyses. Thus, the PeSC with the TPAFS‐TMA HTL exhibits the best power conversion efficiency (PCE) of 20.86%, which is better than that of the PTAA‐based device (PCE of 19.97%). In addition, it exhibits negligible device‐to‐device variations in its photovoltaic performance, contrary to the device with PTAA. Finally, a large‐area PeSC (1 cm2) and mini‐module (3 cm2), showing PCEs of 19.46% and 18.41%, respectively, are successfully fabricated. The newly synthesized TPAFS‐TMA may suggest its great potential as an HTL for large‐area PeSCs.

Bifurcations are the sudden qualitative transitions occurring in dynamical systems due to infinitesimal changes in the control parameters. These abrupt qualitative transitions are crucial in deciding the stable operating regime in the case of a power system. However, in the actual power system, the control parameters such as the electrical power demand, the inertia of the system, damping of the system etc. are found to vary with respect to time. In this paper, bifurcations in an electrical power system for the quasi-static and rate dependent variation of the control parameters are investigated. The canonical power system is represented by assuming a single machine connected to an infinite bus (SMIB). The mathematical modeling of the canonical system is carried out by a second order swing equation model of the generator. We observe a delay in the point of transition for rate-dependent variation of the control parameter, mechanical power, P m . We also investigate the influence of noise and sensitivity to initial conditions in rate-dependent variations of the control parameter. Our study is highly relevant as the stability regimes for the quasi-static and rate dependent variations of control parameters are different.

Controlled and improved power quality is one of the fundamental and essential needs in any industry driven by electric power for optimal exploitation of resources. However, in power quality, some crucial problems have been recognized as harmonic distortion, interruption, sag, swell and transient. Out of these, sag and swell are predominantly seen and cause stern impact on the electrical devices or machines and therefore require to be mitigated at an earliest to protect from any failure or mal-operation. As an ultimate key to crack these problems, some custom power devices such as distribution STATCOM (DSTATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner are unanimously procured. A prominent custom power device DVR is apparently suggested in the literature for the mitigation of voltage sag and swells, with the benefit of active or/and reactive power control. The DVR is reported as being a high-performance solution to compensate voltage disturbances, since it provides both a cost-effective solution and very fast dynamics. In recent years, a bulk amount of the literature accounts for DVR on different configurations of its power circuit and various control techniques employed in it. This review article presents a detailed study on DVR with the different possible configurations of its power circuit and control techniques encircling major power quality issues. The informative object covered in the paper, articulate choice of control strategy and power circuit ensuring optimal recital of DVR in satisfying a required quality. This paper also furnishes the valued information for the investigator in this field.

Cogeneration plants, which simultaneously produce electricity and heat energy, have been introduced increasingly for commercial and domestic applications in Korea because of their energy efficiency. The optimal plant configuration of a specific commercial building can be determined by selecting the sizes and the number of cogeneration systems and the auxiliary equipment based on the annual demands of electricity, heating and cooling. In this study, a mixed-integer, linear programming, utilizing the branch and bound algorithm was used to obtain the optimal solution. Both the optimal configuration system equipment and the optimal operational mode were determined based on the annual cost method for the installation of a cogeneration system to a hospital and a group of apartments in Seoul, Korea. In addition, the economic evaluation for the optimal cogeneration system depending on the fuel tariff system was calculated. A short payback period and higher internal rate of return on the initial investment were found to be essential for the adoption of cogeneration plants to hospitals and apartments.

The Western Rajasthan commonly known as the ‘Indian Thar Desert’ is characterised by harsh climatic conditions with active dunal activities. Precipitation (150–420 mm/yr) is far lower than evapotranspiration potentials (1500–2000 mm/yr). Ground water is limited and often brakish and high (75–100 m) water table. Solar intensity in the region varies from 5.85 to 6.44 kWh/m2/day. Further, peculiarity of the region is that sun is available for 345–355 days in a year, the area being highly scarce in rainfall. On an average, rains occur only for 10.4–20.5 days in a year in the Thar Desert. Therefore, there is high scope to harness solar energy for useful purposes. Considering these solar energy technologies for entrepreneurs, the detailed cost analysis has been worked out and presented. With initial investment of Rs (Indian Rupees) 3.50 lakhs for solar drying projects for handling 60,000 kg fresh vegetables annually (300 working days/yr), the payback period and average net annual returns come to 2.17 years and ...

Abstract SRM (Switched Reluctance motor) is gaining much interest in industries due to its straightforward structure, low-cost manufacturability and dependability which makes it better than other electric machines. SRM drive is the most appropriate for variable speed tasks. Additionally, the performance of the current and speed control for the SRM driver framework could be negatively influenced by noise, disturbances, and inactivity of load torque. To solve this difficulty, this paper develop an ANFIS based Speed and Current control with Torque Ripple Minimization using Hybrid SSD-SFO for SRM. The main goal of this work is to obtain preferred current and speed performance of SRM with minimum torque ripple. For concurrent regulator of the speed and current, an ANFIS (Adaptive Neuro-Fuzzy Inference System) structure is employed which includes two controlling loops. The inside loop is regulated for control of current and the outside loop is regulated for control of speed even with perfect choice of switching angles. The dynamic conduct of SRM is studied to restrict the current and speed that reduces the ripple of torque. Hybrid SSD-SFO (social ski-diver based sunflower optimization) procedure is employed to achieve the parameter values of current and speed control of SRM. The proposed scheme is accomplished by MATLAB/ Simulink environment. The results show that the hybrid SSD-SFO scheme given the better performance compared to the SSD and SFO algorithm.

AbstractTwenty sodium-cooled fast reactors (SFRs) have provided valuable experience in design, licensing, and operation. This paper summarizes the important safety criteria and safety guidelines of intermediate sodium systems, steam generators, decay heat removal systems and associated construction materials and in-service inspection. The safety criteria and guidelines provide a sufficient framework for design and licensing, in particular by new entrants in SFRs.