Influence of load feature on the water distribution system in a centralized air-conditioning system
17 Feb 2017-Science and Technology for the Built Environment (Taylor & Francis)-Vol. 23, Iss: 2, pp 277-284
TL;DR: In this paper, the authors quantitatively describe the asynchronous load demand feature and reveal its relationship with the loss of pump power and heat transfer ability in a centralized air-conditioning water system.
Abstract: On-site investigations show that an asynchronous load feature would greatly influence the operation of water systems for centralized air conditioning. However, the manner of defining the load feature and relating it to its influence quantitatively is still unclear. This article quantitatively describes the asynchronous load demand feature and reveals its relationship with the loss of pump power and heat transfer ability in a centralized air-conditioning water system. The Lorenz curve and the Gini index are introduced in this study and used as indices to depict load features. For a large-scale use in office buildings, shopping malls, and other buildings, the fan coil unit and the variable air volume systems are investigated in this study. The loss of pump power on valves and heat transfer ability under different load profiles are analyzed. This study develops a new perspective of analyzing load patterns and quantitatively explores reasons for the resulting losses in pump power and heat transfer ability in ...
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TL;DR: A methodological framework for model evaluation from an application-oriented perspective is proposed, with lighting behavior as a case study, and the metrics for evaluating lighting behavior models are identified according to different application scenarios, while the comparison between the measurement and simulation is done by introducing the statistical hypothesis testing.
19 citations
TL;DR: Wang et al. as discussed by the authors proposed a new approach to identify and evaluate actual demands characteristics, and their distribution in a quantitative and graphical manner, which can be used to effectively quantify the heating demand and evaluate its non-uniform degree.
TL;DR: In this paper , the authors analyzed the changes in wetland distributions at global, continental, typical regional, and national scales and the conversions between wetlands and other land cover types in the last 20 years.
Abstract: Knowing the distributions and changes in global wetlands and their conversion to other land cover types could facilitate our understanding of wetland development, causes of variations, and decision-making for restoration and protection. This study aimed to comprehensively analyze the changes in wetland distributions at global, continental, typical regional, and national scales and the conversions between wetlands and other land cover types in the last 20 years. This study used GlobeLand30 (GL30) data with a 30 m resolution for the years 2000, 2010, and 2020. The main findings of this study are as follows: (1) the area of wetlands continued to increase globally from 2000 to 2020, with a total increase of approximately 4%. Wetland changes from 2010 to 2020 were more significant than those from 2000 to 2010. The regions with significant wetland changes were mainly in the north middle- and high-latitude, and the equatorial middle- and low-latitude, and Oceania and North America were the continents with the highest increase and decrease, respectively; (2) the major conversion of wetlands was mainly natural land cover types, including forest, grassland, water, and tundra, and there were minor conversions due to human activities, including the conversion of wetlands to cropland (~4600 km2) and artificial land (~3400 km2); (3) from 2000 to 2020, the increase in global wetlands was uneven, while the decrease was nearly even at a national scale. Australia had the highest increase due to the conversions from grass, bare land, and water, and Canada had the highest decrease due to the conversion into tundra and forest. The analysis results could more comprehensively characterize the distributions and changes of global wetlands, which may provide basic information and knowledge for related research work and policymaking.
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TL;DR: In this article, the authors analyzed available information concerning energy consumption in buildings, and particularly related to HVAC systems, and compared different types of building types and end uses in different countries.
5,288 citations
"Influence of load feature on the wa..." refers background in this paper
...Air-conditioning (AC) systems are responsible for the thermal comfort and air quality of buildings and account for approximately 50% of the total amount of electricity used in office buildings (Huang et al. 2006; Perez-Lombard et al. 2008; Zhou et al. 2007)....
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Abstract: you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact support@jstor.org.
1,544 citations
"Influence of load feature on the wa..." refers methods in this paper
...Quantitative description of the asynchronous load demands Lorenz curves and Gini coefficients (Corrado 1921) are commonly used in economics to represent wealth inequality....
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...Lorenz curves and Gini coefficients (Corrado 1921) are commonly used in economics to represent wealth inequality....
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1,189 citations
TL;DR: It is found that the stability of the net ecosystem denitrification in the face of salinity stress was strongly influenced by the initial evenness of the community, therefore, when communities are highly uneven, or there is extreme dominance by one or a few species, their functioning is less resistant to environmental stress.
Abstract: Owing to the present global biodiversity crisis, the biodiversity-stability relationship and the effect of biodiversity on ecosystem functioning have become major topics in ecology. Biodiversity is a complex term that includes taxonomic, functional, spatial and temporal aspects of organismic diversity, with species richness (the number of species) and evenness (the relative abundance of species) considered among the most important measures. With few exceptions (see, for example, ref. 6), the majority of studies of biodiversity-functioning and biodiversity-stability theory have predominantly examined richness. Here we show, using microbial microcosms, that initial community evenness is a key factor in preserving the functional stability of an ecosystem. Using experimental manipulations of both richness and initial evenness in microcosms with denitrifying bacterial communities, we found that the stability of the net ecosystem denitrification in the face of salinity stress was strongly influenced by the initial evenness of the community. Therefore, when communities are highly uneven, or there is extreme dominance by one or a few species, their functioning is less resistant to environmental stress. Further unravelling how evenness influences ecosystem processes in natural and humanized environments constitutes a major future conceptual challenge.
866 citations
"Influence of load feature on the wa..." refers background in this paper
...…in describing inequality in other fields such as the inequality among the sizes of individuals in ecology (Damgaard and Weiner 2000) and in studies of biodiversity, where the cumulative proportion of species is plotted against the cumulative proportion of individuals (Wittebolle et al. 2009)....
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...Both these concepts are also useful in describing inequality in other fields such as the inequality among the sizes of individuals in ecology (Damgaard and Weiner 2000) and in studies of biodiversity, where the cumulative proportion of species is plotted against the cumulative proportion of individuals (Wittebolle et al. 2009)....
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TL;DR: In this article, a new physical quantity E h = 1 2 Q vh T, referred to as entransy, was identified as a basis for optimizing heat transfer processes in terms of the analogy between heat and electrical conduction.
644 citations
"Influence of load feature on the wa..." refers background in this paper
...Entransy (Guo et al. 2007; Zhang et al. 2013), a new parameter defined as the ability for heat transfer, can be used to denote the loss of heat transfer ability during the mixture of water....
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