1,202 research outputs found
Flexible operation of supercritical power plant via integration of thermal energy storage
© 2018 The Author(s).This chapter presents the recent research on various strategies for power plant flexible operations to meet the requirements of load balance. The aim of this study is to investigate whether it is feasible to integrate the thermal energy storage (TES) with the thermal power plant steam-water cycle. Optional thermal charge and discharge locations in the cycle have been proposed and compared. Dynamic modeling and simulations have been carried out to demonstrate the capability of TES integration in supporting the flexible operation of the power plant. The simulation software named SimuEngine is adopted, and a 600 MW supercritical coal-fired power plant model is implemented onto the software platform. Three TES charging strategies and two TES discharging strategies are proposed and verified via the simulation platform. The simulation results show that it is feasible to extract steam from steam turbines to charge the TES and to discharge the stored thermal energy back to the power generation processes. The improved capability of the plant flexible operation is further studied in supporting the responses to the grid load demand changes. The results demonstrated that the TES integration has led to much faster and more flexible responses to the load demand changes.Peer reviewe
Influences of degree inhomogeneity on average path length and random walks in disassortative scale-free networks
Various real-life networks exhibit degree correlations and heterogeneous
structure, with the latter being characterized by power-law degree distribution
, where the degree exponent describes the extent
of heterogeneity. In this paper, we study analytically the average path length
(APL) of and random walks (RWs) on a family of deterministic networks,
recursive scale-free trees (RSFTs), with negative degree correlations and
various , with an aim to explore the
impacts of structure heterogeneity on APL and RWs. We show that the degree
exponent has no effect on APL of RSFTs: In the full range of
, behaves as a logarithmic scaling with the number of network nodes
(i.e. ), which is in sharp contrast to the well-known double
logarithmic scaling () previously obtained for uncorrelated
scale-free networks with . In addition, we present that some
scaling efficiency exponents of random walks are reliant on degree exponent
.Comment: The definitive verion published in Journal of Mathematical Physic
An alternative approach to determining average distance in a class of scale-free modular networks
Various real-life networks of current interest are simultaneously scale-free
and modular. Here we study analytically the average distance in a class of
deterministically growing scale-free modular networks. By virtue of the
recursive relations derived from the self-similar structure of the networks, we
compute rigorously this important quantity, obtaining an explicit closed-form
solution, which recovers the previous result and is corroborated by extensive
numerical calculations. The obtained exact expression shows that the average
distance scales logarithmically with the number of nodes in the networks,
indicating an existence of small-world behavior. We present that this
small-world phenomenon comes from the peculiar architecture of the network
family.Comment: Submitted for publicactio
Research on Intrusion Detection of Database based on Rough Set
AbstractIn this article, we apply the rough set theory to database intrusion detection and monitor the data in real time with intrusion detection. While theory based on rough set will judge the attacks according to the rules and respond to the sample data of intrusion detection after preprocessing them
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