498 research outputs found

    Theoretical investigation of the thermal performance of a novel solar loop-heat-pipe façade-based heat pump water heating system

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    The aim of the paper was to present a dedicated theoretical investigation into the thermal performance of a novel solar loop-heat-pipe façade based heat pump water heating system. This involved thermo-fluid analyses, computer numerical model development, the model running up, modelling result analyses and conclusion. An energy balance network was established on each part and the whole range of the system to address the associated energy conversion and transfer processes. On basis of this, a computer numerical model was developed and run up to predict the thermal performance of such a system at different system configurations, layouts and operational conditions. It was suggested that the loop heat pipes could be filled with either water, R134a, R22 or R600a; of which R600a is the favourite working fluid owing to its relatively larger heat transfer capacity and positive pressure in operation. Variations in the system configuration, i.e., glazing covers, heat exchangers, would lead to identifiable differences in the thermal performance of the system, represented by the thermal efficiency and COP. Furthermore, impact of the external operational parameters, i.e., solar radiation and ambient air temperature, to the system's thermal performance was also investigated. The research was based on an innovative loop-heat-pipe façade and came up with useful results reflecting the thermal performance of the combined system between the façade and heat pump. This would help promote development and market penetration of such an innovative solar heating technology, and thus contribute to achieving the global targets in energy saving and carbon emission reduction

    Allocating Limited Resources to Protect a Massive Number of Targets using a Game Theoretic Model

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    Resource allocation is the process of optimizing the rare resources. In the area of security, how to allocate limited resources to protect a massive number of targets is especially challenging. This paper addresses this resource allocation issue by constructing a game theoretic model. A defender and an attacker are players and the interaction is formulated as a trade-off between protecting targets and consuming resources. The action cost which is a necessary role of consuming resource, is considered in the proposed model. Additionally, a bounded rational behavior model (Quantal Response, QR), which simulates a human attacker of the adversarial nature, is introduced to improve the proposed model. To validate the proposed model, we compare the different utility functions and resource allocation strategies. The comparison results suggest that the proposed resource allocation strategy performs better than others in the perspective of utility and resource effectiveness.Comment: 14 pages, 12 figures, 41 reference

    Reliability model of organization management chain of South-to-North Water Diversion Project during construction period

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    AbstractIn order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project (SNWDP), two basic forms (series connection state and mixed state of both series connection and parallel connection) of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up
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