Abstract

A practical redistribution time-of-use (TOU) demand tariff which allows an aggregator to purchase electricity from grid and redistribute electricity to participants is adopted, a TOU upper demand limit storage control strategy is proposed and applied to a case study of a group of average U.S. households with centralized and distributed storage devices to provide demand response. The impact of the scale of group to provide centralized-storage-based demand response on the economic benefits is also studied. Results show that the proposed control strategy is economically viable and the smallest aggregation scale to obtain the lowest household-average total annual cost is found. The adopted tariff, proposed storage dispatch strategy and the result of this study can be applied to the design of a newly-built storage device sharing among multiple households to provide community-level demand response.

Abstract

With the development of urbanization and industrialization, the dependence on the power system has gradually increased. It is of great significance to discuss the recovery scenario after the power system collapses. Taking the black start event of Hainan Province caused by the typhoon Damrey in 2005 as an example, this study calculates the indirect economic loss of local sectors caused by the black start using the inoperability input-output model and calculates the indirect economic loss under the scenario without the black start based on the assumptions. Through the comparison of these two scenarios, this study analyzes the impact of the black start on post-disaster economic recovery. The results show that the local power load has a rapid growth after the black start, and correspondingly, the daily indirect economic loss drops significantly. The secondary industry sectors suffer relatively larger indirect economic losses, while the primary and tertiary industry sectors are less affected. The black start scenario shows significant advantages

Abstract

In this paper, we investigated the dynamics of Electrical transmission interconnection among countries of the newly formed Eurasian Economic Union (EEU). Though, the union was formed primarily for the basis of trade and labor supplies, the authors felt there may be a good investment opportunity if the countries decide to have a common electricity market. Intensive study was done on the power market existent in each country and the plans of expansion each country is currently pursuing. Russia’s electricity generation and consumption was more than 6 times greater then the production and consumption of all the other 4 countries combined. Then, the transmission lines built during the soviet era were also examined and new opportunities for further collaboration were identified. A generation and transmission expansion planning model was finally developed to investigate the impact of inter-connectivity among the EEU countries. Finally, results

Abstract

This paper evaluates the potential for flexible operation of combined heat and power plants, using previously validated steady-state and dynamic process models. The models compute the change in power and heat generation, as well as the response times of steam turbine extraction regulation. It is found that for small-to-medium sized plants, steam bypass could be a promising solution for regulation of power output, also in combination with boiler load changes. Rise times for load reductions by valve opening are within 30 s, independent of the extracted flow, and steam extractions/bypass can lead to power output reductions of up to 30% of rated power. However, plant specific design aspect may limit the achievable magnitude of load changes and must be considered.

Abstract

Due to the increasing consumption of traditional fossil energy sources and the resulting environmental problems, the need for new energy sources is increasing. Hydrogen is an efficient and clean energy, and developing a suitable hydrogen storage medium is the key to the use of hydrogen energy. Ammonia borane has attracted much attention due to its high hydrogen storage density (19.6 wt %) and room temperature stability. It can be dehydrogenated by hydrolysis and pyrolysis. At present, the pyrolytic dehydrogenation mechanism of ammonia borane is still unclear. In this work, the dehydrogenation of ammonia borane (AB), ammonia borane dimer ((AB)2), and the diaminodiborane (DADB) have been studied based on density functional theory (DFT). The results show that the energy barriers of the first and second steps for AB pyrolytic dehydrogenation are 38.58 kcal/mol and 78.14 kcal/mol. (AB)2 dehydrogenation were generated by forming N-H…H-B bond, the energy barriers for the first step (46.45 kcal/mol) is higher than AB. In addition, the energy barrier (21.67 kcal/mol) of DADB to form N-H…H-B bond dehydrogenation is much smaller than (AB)2. It reveals that DADB is easier to dehydrogenate than AB and (AB)2. The above results would provide theoretical guidance for the pyrolytic dehydrogenation of ammonia borane.

Abstract

In this paper, the effects of injection parameters on combustion and particulate size distribution of partially premixed combustion (PPC) fuel with n-butanol were investigated experimentally. High concentrations of particle emission for the n-butanol PPC combustion are observed. The particle sizes are primarily concentrated within 64nm. With the advance of the start of injection (SOI) timing, more particles are formed and the particulate size distribution curve shifts towards right (larger size). In addition, the pilot-main injection strategy can effectively reduce the maximum pressure rise rate (MPRR). Furthermore, through adopting appropriate injection parameters, the MPRR and particle number can be reduced simultaneously, while still maintaining a comparable indicated thermal efficiency compared to the single injection strategy.

Abstract

The inverted organic solar cell (IOSC) devices with different concentration ratios of nanoparticles In2S3 have been studied under local solar spectrums (sunny and cloudy conditions) in Malaysia as compared to that of AM1.5G. The J-V curves of encapsulated IOSC devices were measured on-site using Ivium Potentialstat and local spectral irradiances were acquired concurrently using AVANTES spectrometer. Despite average photon energy (APE) of both local sunny (1.604 ± 0.010 eV) and AM1.5G conditions (1.603 eV) having almost the same values, the variation in their peak regions is significant in which local sunny condition shows spectral broadening effect with 450 – 640 nm as compared to AM1.5G condition with 447 – 588 nm. The spectral broadening under sunny condition and the bluish-enhancement under cloudy condition have matched well with the light absorption band of the IOSC device. Therefore, power conversion efficiency (PCE) of IOSC devices under local sunny condition relative to AM1.5G condition shows the substantial improvement with gain of 26.4 – 50.0 %, while the devices operate at even higher PCE under cloudy condition with gain of 31.8 – 68.8%.

Abstract

The intensive energy penalty for amine solvent regeneration in the absorption/desorption process considered one of the major obstacles of this technology. Therefore, a series of a super solid acid catalyst (SO42-/SnO2, SO42-/ZrO2, and mesoporous silica Kit-6) were synthesized and studied separately to investigate their effectiveness on monoethanolamine (MEA) solvent regeneration at 97°C. It has been observed that all the catalysts promote the CO2 desorption performance, the Kit-6 exhibit the best catalytic performance which can enhance the desorption rate by 43.90% and reduce the energy consumption by 34.6% compare to monoethanolamine (MEA) without catalysts, whereas other solid acid catalysts, SO42-/SnO2 and SO42-/ZrO2 exhibited a significant change in amine regeneration performance at the same conditions. The rich-MEA regeneration performance order was MEA-Kit-6 > MEA-SO42-/SnO2 > MEA-SO42-/ZrO2 > MEA without a catalyst. Based on the obtained results, the application of this work will open a new path in CO2 stripping process to reduce the regeneration energy requirements and enhancing the desorption rate, which would decrease the operating costs of rich amine solvent regeneration.

Abstract

Low-grade heat from industrial exhaust gases can be recovered for electricity generation by various thermodynamic cycles. Previous studies assumed that only sensible heat is available for the heat recovery. However, in fact, the moisture content is commonly high and as the moisture condenses, a significant amount of latent heat is released. To gain further understanding of the effect of the moisture, we carried out comparative analyses among a basic organic Rankine cycle (ORC) and alternative cycles, including organic flash cycle (OFC), Kalina cycle (KCS) and transcritical ORC (T-ORC). Furthermore, the performance of an advanced dual-pressure ORC (DPORC) was evaluated under a wet gas scenario. The results show that by taking into account the moisture condensation heat, the net power output per kg/s of heat source flow increases significantly for all cycles examined although the exergy efficiency, known as an indicator for system irreversibility, tends to drop. Regardless of the level of moisture content in the heat source, ORC and T-ORC always have higher performance than OFC and KCS. In a case study using a moisture content of 0.1 in the heat source, a DPORC can achieve a performance enhancement by 58% compared with a simple ORC.

Abstract

Owing to the rapid development of the global economy, the demand for energy and water resources is the main global challenge in the 21st century. This article focuses on the consumption and transfer of the water resources in China’s West–East electricity transmission project. The input–output method is employed to construct a water footprint assessment model for this project. Results show that 606.4 billion kWh of electricity and 2.5 billion m3 of virtual water were transferred from the western to eastern region in 2016. Coordinated policy making the optimal use of water resources for energy generation needs to be further discussed for promoting sustainable regional development.