scholarly journals Binary Linear Programming as a Tool of Cost Optimization for a Water Supply Operator

2021 ◽  
Vol 13 (6) ◽  
pp. 3470
Author(s):  
Przemysław Kowalik ◽  
Magdalena Rzemieniak

The problem of scheduling pumps is widely discussed in the literature in the context of improving energy efficiency, production costs, emissions, and reliability. In some studies, the authors analyze the available case studies and compare the results; others present their own computational methods. In the paper, a problem of pump scheduling in regular everyday operations of a water supply operator is considered. The issues of water production optimization and energy savings are part of the topic of sustainable development. The objective of the article is the minimization of the cost of electric power used by the pumps supplying water. It is achieved thanks to the variability of both the demand for water and the price of electric power during the day combined with the possibility of storing water. The formulation of an existing electric power cost optimization problem as a binary linear programming problem was improved. An essential extension of the above mathematical model, which enables more flexible management of the pump system, was also proposed. An example containing real-world input data was successfully solved using Microsoft Excel with a free OpenSolver add-in.

2011 ◽  
Vol 3 (2) ◽  
pp. 118-120
Author(s):  
Salma Shaheen ◽  
◽  
Tazyeen Ahmad

Author(s):  
T. Movchan ◽  
V. Artеmov ◽  
D. Bulysheva

It is recommended to implement forecasting management models in the area of land use and protection by applying linear programming methods to optimize the size of farms, which land is located in different natural and economic zones. Analysis and assessment of land use in natural-economic zones is a type of management activity for deep understanding of the dialectic of a managed object development and true assessment of its moving forces. This enables to simulate the situation of land use, to identify a specific goal, to choose the means to achieve it and to obtain the optimum result. The implementation of the proposed forecast models of the optimal farm size is carried out by linear programming in three ways (northwest corner method, minimum cost method and What-If analysis method, that uses Solver, a Microsoft Excel add-in program). The implementation of the above approaches is based on the example of four farms and five natural-economic zones. The obtained solutions show that the best result is attained by using Solver for What-If analysis method, a Microsoft Excel add-in program. The northwest corner method gives the worst result, but this is the simplest solution. The minimum cost method depends on the researcher qualification and produces the result that is most often found between the results obtained by the northwest corner method and the "Solver" procedure. When using the method of the northwest corner a program of consideration of different options for the distribution of land resources and the choice of the optimal solution was developed. This allows to find an optimal result of land allocation according to the result, which is similar to the result of the procedure "Solver", but it is more adapted for the direct participation of the researcher in the process of solving problems. There is an opportunity to improve the result by changing the original data, which simulates the forecast of the distribution of farm land in natural-economic zones, while minimizing production costs. In the absence of access to computers, the solutions obtained by the northwest corner and the minimum cost methods can be improved by the potential method.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Christophe Mariat ◽  
Jocelyne Rey ◽  
Annie Olivier ◽  
Perrine Jullien

Abstract Background and Aims The environmental impact of dialysis is now being largely recognized. It requires from the nephrology community to actively explore novel environmentally responsible health-care practices. Among them, conception of energy-efficient facilities may be an important prerequisite for improving the environmental impact of dialysis. The Passive House concept is an internationally recognised, performance-based energy standard in construction which so far has been rarely applied to medical facilities and never to dialysis centres. We report our experience with the first passive-house certified dialysis facility in Europe. Method The Passive House concept is a sustainable construction standard for nearly zero energy buildings (the Resolution of the European Parliament of 31/01/2008 has called for its implementation by all member states by 2021). Principles and design tools of the Passive House concept are freely available for all architects. The concept combines a particularly high level of insulation with a specific system of ventilation. Geothermal energy and energy from inside the building such as the body heat from the residents or solar heat entering the building are the main energy sources. Passive House buildings allow for heating and cooling related energy savings of up to 90% compared with typical building stock and over 75% compared with average new buildings. Results The François Berthoux Center (www.artic42.fr) is a 4 400 m2 dialysis facility operated by 40 health care agents and providing care to 135 patients. It was designed following the Passive-House standard, applied for the first time to such a medical building. Several adjustments specific to the dialysis activity were necessary. The most unexpected aspect was the importance of hemodialysis machines as an energy source. Thorough thermal evaluation showed that the heat provided by different type of hemodialysis machines was systematically superior to the energy mandatory during the coldest day of the year (>10 W/m2). In practice, the center turned out to be fully operational with no external source of heating. The downside was that the geothermal pump system was not sufficient to fully regulate temperatures during the warmest period of the year. Optimal cooling was achieved by the addition of conventional AC systems in the hemodialysis rooms. Overall, as compared to a similar center, energy savings provided by the The François Berthoux Center were substantially less than what is expected from a conventional Passive House building but were over 50%. The extra-cost of the construction was estimated to 3 to 5%. Conclusion In conclusion, the concept of eco-friendly building should extend to dialysis facilities. Application of the Passive House Standard in the context of hemodialysis requires to take into account some specificities that can impact the global environmental performance of the building. However, the net result is clearly in favor of such a construction, which is both affordable and sustainable.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Changyu Zhou ◽  
Guohe Huang ◽  
Jiapei Chen

In this study, an inexact two-stage stochastic linear programming (ITSLP) method is proposed for supporting sustainable management of electric power system under uncertainties. Methods of interval-parameter programming and two-stage stochastic programming were incorporated to tackle uncertainties expressed as interval values and probability distributions. The dispatchable loads are integrated into the framework of the virtual power plants, and the support vector regression technique is applied to the prediction of electricity demand. For demonstrating the effectiveness of the developed approach, ITSLP is applied to a case study of a typical planning problem of power system considering virtual power plants. The results indicate that reasonable solutions for virtual power plant management practice have been generated, which can provide strategies in mitigating pollutant emissions, reducing system costs, and improving the reliability of power supply. ITSLP is more reliable for the risk-aversive planners in handling high-variability conditions by considering peak-electricity demand and the associated recourse costs attributed to the stochastic event. The solutions will help decision makers generate alternatives in the event of the insufficient power supply and offer insight into the tradeoffs between economic and environmental objectives.


2015 ◽  
Vol 187 ◽  
pp. 6-13 ◽  
Author(s):  
Jingzheng Ren ◽  
Liang Dong ◽  
Lu Sun ◽  
Michael Evan Goodsite ◽  
Shiyu Tan ◽  
...  

Author(s):  
Chao Liu

There are many pumps working in generating plant for pumping water in the cooling system. The pumps consume a big amount of electricity especially in large generating plant which operates continuously for long time. Therefore, the electric power cost will increase with increasing of operation cost of the pumping system. It is very important to minimize the operation cost of the pumping system to optimize the use of generating plant assets. In order to optimize the operation of pumping system the method of adjusting pump rotation speeds are often adopted. The fundamental factor of optimizing pump operation is to obtain the operation performance. Theoretically the affinity law (special modeling Equation) of pumps can be applied to convert the performances of pumps under rated speeds to variable rotation speeds. However the affinity law can only be applied in the region of pump operation around Best Efficiency Point with an acceptable precision. Also the affinity law derived from the Modeling Equation can only be valid to pump or pump bowl rather than pumping system. In this paper a method was conducted to determine the performances of pumping system based on the computational and experimental results. The principle of optimizing the pumping system is discussed. Finally the optimizing operation alternative of the pumping system is presented.


Author(s):  
José Manuel Velarde-Cantú ◽  
Mauricio López-Acosta ◽  
Allán Chacara-Montes ◽  
Ernesto Ramírez-Cárdenas

This paper addresses the problem of production scheduling under a practical approach, which seeks to find out what would be the product mix to ensure the company to obtain the most useful, also requires that these combinations of products obtained from quickly and efficiently contributing thus to achieve lower costs associated with production. A specific mathematical model based on integer linear programming applied specifically to the product mix is presented, as well as the results obtained from the practical problem from the use of the model in integer linear programming, the use of the software and considering the own conditions of the problem addressed here.


Sign in / Sign up

Export Citation Format

Share Document