Modeling the Efficiency and Power Characteristics of a Pump Group

Ulanicki, Bogumił; Kahler, Jens; Coulbeck, B.

doi:10.1061/(asce)0733-9496(2008)134:1(88)

Cited by 93 publications

(45 citation statements)

References 3 publications

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“…In addition, they are low cost machines and have relatively high efficiency, which can be considered relatively constant if the motor operates above 50% of the rated load [24]. The rated speed of an induction motor (IM) is usually very close (90%-99%) to the synchronous speed that is determined by the supply frequency and can be altered by a VFD.…”

Section: Motor Optionsmentioning

confidence: 99%

Energy Savings Potential for Pumping Water in District Heating Stations

Sârbu

Valea

2015

Sustainability

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Abstract:In district heating stations, the heat carrier is circulated between the energy source and consumers by a pumping system. Fluid handling systems, such as pumping systems, are responsible for a significant portion of the total electrical energy use. Significant opportunities exist to reduce pumping energy through smart design, retrofitting, and operating practices. Most existing systems requiring flow control make use of bypass lines, throttling valves or pump speed adjustments. The most efficient of these options is pump speed control. One of the issues in using variable-speed pumping systems, however, is the total efficiency of the electric motor/pump arrangement under a given operating condition. This paper provides a comprehensive discussion about pump control in heating stations and analyzes the energy efficiency of flow control methods. Specific attention is also given to the selection of motor types, sizing and pump duty cycle. A comparative energy analysis is performed on the hot water discharge adjustment using throttling control valves and variable-speed drives in a district heating station constructed in Romania. To correlate the pumped flow rate with the heat demand and to ensure the necessary pressure using minimum energy, an automatic system has been designed. The performances of these control methods are evaluated in two practical applications. The results show that approximately 20%-50% of total pumping energy could be saved by using the optimal control method with variable-speed pumps. Additionally, some modernization solutions to reduce the environmental impact of heating stations are described. OPEN ACCESSSustainability 2015, 7 5706

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Section: Motor Optionsmentioning

confidence: 99%

Energy Savings Potential for Pumping Water in District Heating Stations

Sârbu

Valea

2015

Sustainability

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“…To model electricity usage, instead of using a pump efficiency equation a direct modelling of pump station power is employed, as discussed in Ulanicki et al (2008). However, the equation is rearranged to allow zero pumps switched on, without introducing if-else formulas:…”

Section: Pump Stationsmentioning

confidence: 99%

Pump schedules optimisation with pressure aspects in complex large-scale water distribution systems

Skworcow

Paluszczyszyn

Ulanicki

2014

Drink. Water Eng. Sci.

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Abstract. This paper considers optimisation of pump and valve schedules in complex large-scale water distribution networks (WDN), taking into account pressure aspects such as minimum service pressure and pressuredependent leakage. An optimisation model is automatically generated in the GAMS language from a hydraulic model in the EPANET format and from additional files describing operational constraints, electricity tariffs and pump station configurations. The paper describes in details how each hydraulic component is modelled. To reduce the size of the optimisation problem the full hydraulic model is simplified using module reduction algorithm, while retaining the nonlinear characteristics of the model. Subsequently, a nonlinear programming solver CONOPT is used to solve the optimisation model, which is in the form of Nonlinear Programming with Discontinuous Derivatives (DNLP). The results produced by CONOPT are processed further by heuristic algorithms to generate integer solution. The proposed approached was tested on a large-scale WDN model provided in the EPANET format. The considered WDN included complex structures and interactions between pump stations. Solving of several scenarios considering different horizons, time steps, operational constraints, demand levels and topological changes demonstrated ability of the approach to automatically generate and solve optimisation problems for a variety of requirements.

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“…In addition, they are low cost machines, are reliable and have relatively high efficiency, which can be considered relatively constant if motor operates above 50 % of rated load (Ulanicki et al, 2008). The rated speeds of induction motor (IM) is usually very close (typically 90-99 % depending on machine size) to synchronous speed that is determined by the supply frequency and can be altered by a variable frequency drive.…”

Section: Motor Optionsmentioning

confidence: 99%

Assessing variable speed pump efficiency in water distribution systems

Marchi

Simpson

Ertugrul

2012

Drink. Water Eng. Sci.

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Abstract. Energy savings and greenhouse gas emission reductions are increasingly becoming important design targets in many industrial systems where fossil fuel based electrical energy is heavily utilised. In water distribution systems (WDSs) a significant portion of operational cost is related to pumping. Recent studies have considered variable speed pumps (VSPs) which aim to vary the operating point of the pump to match demand to pumping rate. Depending on the system characteristics, this approach can lead to considerable savings in operational costs. In particular, cost reductions can take advantage of the demand variability and can decrease energy consumption significantly. One of the issues in using variable speed pumping systems, however, is the total efficiency of the electric motor/pump arrangement under a given operating condition. This paper aims to provide a comprehensive discussion about the components of WDS that incorporate variable speed pumps (including electric motors, variable frequency drives and the pumps themselves) to provide an insight of ways of increasing the system efficiency and hence to reduce energy consumption. In addition, specific attention is given to selection of motor types, sizing, duty cycle of pump (ratio of on-time and time period), losses due to installation and motor faults. All these factors affect the efficiency of motor drive/pump system.

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Modeling the Efficiency and Power Characteristics of a Pump Group

Cited by 93 publications

References 3 publications

Energy Savings Potential for Pumping Water in District Heating Stations

Energy Savings Potential for Pumping Water in District Heating Stations

Pump schedules optimisation with pressure aspects in complex large-scale water distribution systems

Assessing variable speed pump efficiency in water distribution systems

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