scholarly journals Reducing energy waste in centrifugal pump systems through the implementation of BEP optimized pressure and flow control

2015 ◽  
Author(s):  
◽  
Shane Corlman
Keyword(s):  
Centrifugal Pump ◽  
Energy Savings ◽  
Control Valve ◽  
Speed Control ◽  
Variable Speed ◽  
Centrifugal Pumps ◽  
Efficiency Curve ◽  
System Variable ◽  
Applicable Range ◽  
Drive And Control

There currently exists a gap in the technology surrounding centrifugal pumps. When looking at modern literature regarding the application of centrifugal pump systems, the existing methods for control are throttle and speed control. Herein is described a new method, one which uses both throttle and speed control simultaneously to allow for the ability to precisely regulate pressure and flow for an entire system. Variable speed pumping, when combined with a control valve allows for control techniques which have the goal of optimizing the efficiency of the pump instead of just controlling flowrate. Developing a variable speed characterization and finding the best efficiency curve of a pump gives all the necessary tools to create a "dual controller" to operate a pump in the region of greatest reliability, always. Experiments show that neither fixed speed operation nor variable speed operation without a control valve can accurately maintain operation at the best efficiency point of the pump. Therefore, a novel control system using both a variable speed pump and a control valve is proposed to replace individual throttle and speed control. The proposed system, when used with the best efficiency curve as the operational target, maintains the best efficiency point for any flow requirement within the applicable range of the pump. Additionally, experiments have shown that energy savings from the proposed control scheme can exceed 60% -- a savings which no fixed speed system can match. Dual control with a variable speed drive and control valve can reduce energy consumption and increase pump life and reliability when compared to throttle control or speed control alone by reducing the amount of time that the pump is operating away from its best efficiency point. Similarly, it provides the tools needed to produce any performance that an operator desires, whatever the application may be.

scholarly journals Energy-saving potential for centrifugal pump storage operation using optimized control schemes

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas Hieninger ◽  
Florian Goppelt ◽  
Ronald Schmidt-Vollus ◽  
Eberhard Schlücker
Keyword(s):  
Energy Saving ◽  
Centrifugal Pump ◽  
Energy Savings ◽  
Control Strategies ◽  
Frequency Converter ◽  
Operating Time ◽  
Speed Control ◽  
Centrifugal Pumps ◽  
Constant Flow Rate ◽  
Energy Saving Potential

AbstractIn this paper, we present the energy-saving potential of using optimized control for centrifugal pump–driven water storages. For this purpose, a Simulink pump-pipe-storage model is used. The equations and transfer function for steady-state and transient system behavior are presented and verified. Two different control strategies—optimum constant flow rate and level guided speed control—are compared to an allegedly optimal-driven pump with constant rotational speed. Twelve centrifugal pumps between 1 and 120 kW nominal power are evaluated to analyze the influence of different system parameters. The system characteristics, which are the static head, dynamic head factor, and maximum filling head, are varied 25 times for each pump in consideration of the pump’s best efficiency point. Thus, 300 different systems are optimized for each control strategy and compared to the constant speed control. The results are analyzed and the relevant system’s parameters, which have the most significant impact on energy savings, are shown. This theoretical energy–saving potential is verified with measurements, which show the high impact of the part load losses of the frequency converter and the electric motor. A law for identifying and estimation potential energy savings is developed using this information. Four use cases are analyzed with this law. It is shown that for a cost-minimal operation, not only the savings potential but also the operating time is decisive.

scholarly journals Using Variable Speed Control on Pump Application

2012 ◽  
Vol 2 (1) ◽  
pp. 251
Author(s):  
Dr.Sc. Aida Spahiu ◽  
Dr.Sc. Orion Zavalani ◽  
MSc. Altin Uka
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Speed Control ◽  
Reference Points ◽  
The European Union ◽  
Variable Speed ◽  
Centrifugal Pumps ◽  
Variable Speed Drive ◽  
Carbon Dioxide Co2 ◽  
Variable Speed Control

Pumps are one of the most common variable speed drive (VSD) system applications and special interest has focused on improving their energy efficiency by using variable speed control instead of throttling or other less efficient flow control methods. Pumps are the single largest user of electricity in industry in the European Union, consuming 160 TWh per annum of electricity and accounting for 79 million tonnes of carbon dioxide (CO2) emissions [1]. Centrifugal pumps are the most likely pump style to provide a favorable return based on energy savings when applied with a variable speed drive. To help illustrate this, are conducted benchmark testing to document various head and flow scenarios and their corresponding effect on energy savings. Paper shows the relationship of static and friction head in the energy efficiency equation and the effect of motor, pump and VSD efficiencies. The received results are good reference points for engineers and managers of water sector in Albania to select the best prospects for maximizing efficiency and energy savings.

Mathematical modelling of supermarket refrigeration systems for design, energy prediction and control

2000 ◽  
Vol 214 (2) ◽  
pp. 101-114 ◽  
Author(s):  
Y T Ge ◽  
S A Tassou
Keyword(s):  
Energy Savings ◽  
Control Strategies ◽  
Speed Control ◽  
Variable Speed ◽  
Ambient Conditions ◽  
Energy Prediction ◽  
Head Pressure ◽  
Component Models ◽  
And Control ◽  
Variable Speed Control

This paper describes a mathematical model developed to simulate the performance of supermarket refrigeration systems. Such a model can be used for the comparison of different systems and control strategies in terms of their energy and total equivalent warming impact. The model is based on a large number of component models which have been linked together within the TRNSYS environment. Major component models include the compressor, air-cooled condenser, thermostatic expansion valve, display cabinet and control. The overall system model has been validated against monitored data obtained from both a laboratory-based system and a full-scale system in a supermarket in Scotland. The value of the model is illustrated by determining and comparing the effectiveness of head pressure and variable-speed control against fixed head pressure and constant speed control. It is shown that even at summer ambient conditions the system can be operated without problems at much lower head pressures than is done in practice under fixed-pressure control strategies. The use of variable-speed control on one of the compressors can also provide better control of the suction pressure and a substantial (up to 23 per cent) energy savings compared to on-off control.

scholarly journals Dynamical Modeling of Frequency Controlled Variable Speed Parallel Multistage Centrifugal Pumps

2015 ◽  
Vol 62 (3) ◽  
pp. 347-362 ◽  
Author(s):  
Farid Khayatzadeh ◽  
Jafar Ghafouri
Keyword(s):  
Flow Rate ◽  
Control Strategy ◽  
Control Method ◽  
Speed Control ◽  
Constant Speed ◽  
Variable Step Size ◽  
Variable Speed ◽  
Centrifugal Pumps ◽  
Step Size ◽  
Pumping System

Abstract This paper presents a development of a model of a set of multistage centrifugal electro pumps including two 4 stage stainless steel centrifugal pumps, each coupled to a 4 kW three-phase induction motor, connected to a hydraulic application running under two control strategies including constant speed and variable speed methods. Each pump provides 16 m3/hr flow rate and 58mwater head at BEP (Best Efficiency Point). Dynamicity of the model causes variations in all operational parameters of pumping system in any variation on consuming flow rate. Each electro pump has been driven with a variable frequency drive utilizing frequency control method for adjusting the rotational speed under a PID control regarding to match of pumping system operational point with the consumption point to save the energy. 83% energy saving is achieved by model in variable speed control strategy comparing to constant speed control strategy. MATLAB/SIMULINK software using ode45 solver and variable step size simulates this model.

Effect of semi-open impeller side clearance on centrifugal pump cavitation inception

2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Rotation Speed ◽  
Centrifugal Pumps ◽  
Severe Condition ◽  
Cavitation Inception ◽  
Total Input ◽  
Input Pressure ◽  
Pump Head ◽  
Pump Pressure

Cavitation in pumps is the most severe condition that centrifugal pumps can work in and is leading to a loss in their performance.  Herein, the effect of semi-open centrifugal pump side clearance on the inception of pump cavitation has been investigated.  The input pump pressure has been changed from 80 to 16 kPa and the pump side clearance has been changed from 1 mm to 3 mm at a rotation speed of 1500 rpm. It has been shown that as the total input pressure decreased; the static pressure inside the impeller is reduced while the total pressure in streamwise direction has been reduced, also the pump head is constant with the reduction of the total input pressure until the cavitation is reached. Head is reduced due to cavitation inception; the head is reduced in the case of a closed impeller with a percent of 1.5% while it is reduced with a percent of 0.5% for pump side clearance of 1mm, both are at a pressure of 20 kPa.   Results also showed that the cavitation inception in the pump had been affected and delayed with the increase of the pump side clearance; the cavitation has been noticed to occur at approximate pressures of 20 kPa for side clearance of 1mm, 18 kPa for side clearances of 2mm and 16 kPa for 3mm.

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

scholarly journals Design and Optimization of a Centrifugal Pump for Slurry Transport Using the Response Surface Method

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Khaled Alawadhi ◽  
Bashar Alzuwayer ◽  
Tareq Ali Mohammad ◽  
Mohammad H. Buhemdi
Keyword(s):  
Response Surface ◽  
Centrifugal Pump ◽  
Industrial Applications ◽  
Pump Efficiency ◽  
Optimized Design ◽  
Centrifugal Pumps ◽  
Local Pressure ◽  
Design And Optimization ◽  
Geometry Characteristic ◽  
Line Design

Since centrifugal pumps consume a mammoth amount of energy in various industrial applications, their design and optimization are highly relevant to saving maximum energy and increasing the system’s efficiency. In the current investigation, a centrifugal pump has been designed and optimized. The study has been carried out for the specific application of transportation of slurry at a flow rate of 120 m3/hr to a head of 20 m. For the optimization process, a multi-objective genetic algorithm (MOGA) and response surface methodology (RSM) have been employed. The process is based on the mean line design of the pump. It utilizes six geometric parameters as design variables, i.e., number of vanes, inlet beta shroud, exit beta shroud, hub inlet blade draft, Rake angle, and the impeller’s rotational speed. The objective functions employed are pump power, hydraulic efficiency, volumetric efficiency, and pump efficiency. In this reference, five different software packages, i.e., ANSYS Vista, ANSYS DesignModeler, response surface optimization software, and ANSYS CFX, were coupled to achieve the optimized design of the pump geometry. Characteristic maps were generated using simulations conducted for 45 points. Additionally, erosion rate was predicted using 3-D numerical simulations under various conditions. Finally, the transient behavior of the pump, being the highlight of the study, was evaluated. Results suggest that the maximum fluctuation in the local pressure and stresses on the cases correspond to a phase angle of 0°–30° of the casing that in turn corresponds to the maximum erosion rates in the region.

Sign in / Sign up

Export Citation Format

Share Document