Conversion Function and Relationship of Loss of Load Expectation Indices on Two Kinds of Load Duration Curve

Important investmentsare made lately in the area of district heating, as a technology capable ofhelping countries to reach sustainability goals. In Romania, European fundswere spent for transition from the 2nd to the 3rdgeneration of district heating systems. The lack of appropriate monitoringsystems in old district heating systems makes optimisation nowadays very difficult,especially because nominal values used in the first design stage areoverestimated. Realistic nominal heat loads are necessary to make goodestimations of hydraulic parameters to be used for redesign. This studyproposes a method that uses the heat load duration curve theory to identify theappropriate nominal heat loads to be used for redesign. Comparison betweenresults obtained by applying the nominal heat loads of each consumer, as theywere established in the first design stage, and the ones identified by theproposed method are analyzed in a case study. The results show that errors arein the +/- 3% band, between the metered heat consumption rates and the proposedrates. The new method can be used for the sizing of pumps and district heatingnetworks after retrofit, in order to get better adjustments of the circulationpumps and increase of the energy efficiency.

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Long-Term Forecasts of Optimal Approximations to the Load Duration Curve

Journal of the Operational Research Society ◽

10.1057/jors.1980.61 ◽

1980 ◽

Vol 31 (4) ◽

pp. 343-347 ◽

Cited By ~ 1

Author(s):

Noel D. Uri ◽

John S. Maybee

Keyword(s):

Load Duration ◽

Load Duration Curve

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A Study of the Load Allocation using Watershed Model and Load Duration Curve in TMDL

KSCE Journal of Civil Engineering ◽

10.1007/s12205-018-0910-0 ◽

2018 ◽

Vol 22 (9) ◽

pp. 3222-3232 ◽

Cited By ~ 1

Author(s):

Eun Jeong Lee ◽

Tae Geun Kim ◽

Kyoung-sik Choi

Keyword(s):

Watershed Model ◽

Load Duration ◽

Load Duration Curve

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Development of load duration curve system in data-scarce watersheds based on a distributed hydrological model

Hydrology Research ◽

10.2166/nh.2019.117 ◽

2019 ◽

Vol 50 (3) ◽

pp. 886-900

Author(s):

Jia Wang ◽

Xin-hua Zhang ◽

Chong-Yu Xu ◽

Hao Wang ◽

Xiao-hui Lei ◽

...

Keyword(s):

Hydrological Model ◽

Assessment Tool ◽

Swat Model ◽

River Basins ◽

Point Sources ◽

Guizhou Province ◽

Polluted Water ◽

Distributed Hydrological Model ◽

Load Duration ◽

Load Duration Curve

AbstractMany developing countries and regions are currently facing serious water environmental problems, especially the lack of monitoring systems for medium- to small-sized watersheds. The load duration curve (LDC) is an effective method to identify polluted waterbodies and clarify the point sources or non-point sources of pollutants. However, it is a large challenge to establish the LDC in small river basins due to the lack of available observed runoff data. In addition, the LDC cannot yet spatially trace the specific sources of the pollutants. To overcome the limitations of LDC, this study develops a LDC based on a distributed hydrological model of the Soil and Water Assessment Tool (SWAT). First, the SWAT model is used to generate the runoff data. Then, for the control and management of over-loaded polluted water, the spatial distribution and transportation of original sources of point and non-point pollutants are ascertained with the aid of the SWAT model. The development procedures of LDC proposed in this study are applied to the Jian-jiang River basin, a tributary of the Yangtze River, in Duyun city of Guizhou province. The results indicate the effectiveness of the method, which is applicable for water environmental management in data-scarce river basins.

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On the optimal composition of electricity grids with unreliable units: solvable models

Advances in Applied Probability ◽

10.2307/1427146 ◽

1985 ◽

Vol 17 (2) ◽

pp. 367-385 ◽

Cited By ~ 1

Author(s):

D. J. Gates

Keyword(s):

Load Distribution ◽

Rayleigh Distribution ◽

Explicit Solutions ◽

Optimal Composition ◽

Solvable Models ◽

Electricity Grid ◽

Load Duration ◽

Load Duration Curve ◽

Electricity Grids ◽

Total Capacity

For a large electricity grid comprising many units (plants) of various types, such as coal, oil, nuclear, hydro, etc., with known unreliabilities (outage rates) we study the optimal (i.e. the cheapest) total capacity, or numbers, of each type of unit. Existing treatments of the problem involve numerical methods and approximations of unknown accuracy. For a range of cases, we find explicit solutions. This extends the known explicit solutions, which are confined to completely reliable units. The cases we analyse are (I) a demand (load) which has a shifted Rayleigh distribution—a good approximation to the real load-duration curve—with some restriction on reliability (big units are more reliable) and (II) an exponential load distribution—which is unrealistic—with no restrictions on reliability. In both cases, the solutions reduce to transformed versions of the exact solutions for totally reliable units and, like the latter, can be exhibited by means of a cost polygon.

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