Parallel Pump System Research Articles

Parallel pump and chiller system optimization method for minimizing energy consumption based on a novel multi-objective gorilla troops optimizer

Minimizing the energy usage of the parallel pump and chiller system is a crucial method for lowering buildings’ energy consumption. The variations in the cooling load of buildings should be taken into account when optimizing the operation of the parallel pump and chiller system. Although several strategies have been put forth, it is challenging to operate at a general optimal level. The parallel pump and chiller system with different chillers and pumps is frequently used in practical applications but is rarely taken into account in literature. Hence, we propose a two-step energy consumption optimization method for a parallel pump and chiller system with different chillers and pumps based on a novel multi-objective gorilla troops optimizer (MOGTO). The gorilla troops optimizer (GTO), which makes use of an exclusive non-dominated sorting (NDS) and a diversity-preserving crowding distance (CD) mechanism, is the inspiration for the proposed MOGTO method. By resolving the trade-off between chillers and pumps, a holistic optimization based on the MOGTO algorithm was carried out to determine the least amount of energy used overall. By optimizing practical parameters, including binary and continuous variables, the overall energy consumption as well as the difference between the flow rates of pumps and chillers were simultaneously reduced. A simulation was used to examine the suggested strategy. The outcomes imply that the optimization was made logically.

Flow distribution optimization of parallel pumps based on improved mayfly algorithm

An improved mayfly algorithm is proposed for the energy saving optimization of parallel chilled water pumps in central air conditioning system, with the minimum energy consumption of parallel pump units as the optimization objective and the speed ratio of each pump as the optimization variable for the solution. For the problem of uneven random initialization of mayflies, the variable definition method of Circle chaotic mapping is used to make the initial position of the population uniformly distributed in the solution space, and the mayfly fitness value and the optimal fitness value are incorporated into the calculation of the weight coefficient, which better balances the global exploration and local exploitation of the algorithm. For the problem that the algorithm is easy to fall into the local optimum at the later stage, a multi-subpopulation cooperative strategy is proposed to improve the global search ability of the algorithm. Finally, the performance of the improved mayfly algorithm is tested with two parallel pumping system cases, and the stability and time complexity of the algorithm are verified. The experiments show that the algorithm can get a better operation strategy in solving the parallel water pump energy saving optimization problem, and can achieve energy saving effect of 0.72% 8.68% compared with other optimization algorithms, and the convergence speed and stability of the algorithm have been significantly improved, which can be better applied to practical needs.

Development, validation and application of an energy model for energy efficient operation of parallel pump systems

Parallel pumps are commonly applied in chilled water and hot water systems to handle broad water flow variation. The application of variable frequency drives leaves the sequencing control of parallel pumps a tricky problem, especially if the pumps have various sizes or/and experience various speeds. The objective of this paper is to develop and validate an energy model to optimize the operation of parallel pump systems. First a comprehensive energy model is developed based on the affinity and Kirchhoff Laws. The pump installed head is applied to eliminate the impact of the pump fittings and the drive efficiency is considered to obtain the true electrical power. Then, the energy model is constructed and validated for a parallel pump system, which has three 284 L/s pumps with one as a backup pump and each powered by a 150 kW motor. Finally, the validated model is applied to identify the energy efficient operation. The results reveal that one-pump operation outperforms two-pump operation at lower flow range with the switchover flowrate decreasing from 300 L/s to 240 L/s as the controlled pump installed head varies from a constant setpoint to a reset variable setpoint. Moreover, faulty various speed settings result in the electrical power waste of 20 kW for the lower-speed pump.

Investigation of Energy-Saving Strategy for Parallel Variable Frequency Pump System Based on Improved Differential Evolution Algorithm

This paper presents an energy-saving strategy that was applied to a parallel variable frequency pump system of a water circulation pumping station. Firstly, the mathematical model of shaft power consumption for the parallel pump system was established using quadratic polynomial fitting, with some constraints configured according to the system’s water supply demands. Then, the algorithm program was designed with the goal of minimizing the energy consumption through the application of an improved differential evolution algorithm. Additionally, the energy consumption model and constraints were integrated and simplified in order to adapt to the algorithm calculation. In the end, the algorithm was implemented according to the pump design parameters and supply targets of the pumping station. Meanwhile, a comparison was done between the differential evolution (DE) algorithm and the genetic algorithm (GA). Furthermore, an experimental test was conducted in an aluminum company in order to verify the applicability of the energy-saving algorithm in practice. The results demonstrated the feasibility of using the improved differential evolution algorithm in order to achieve a minimum energy consumption operation strategy; the results consequently manifested the superiority of the differential evolution algorithm in both computing time and optimal solution aspects.

Save Energy in Choosing Oil Pumping Systems

Some non-specialists raised problems about the turbine pumping system in the Al-Faw oil depot, and it reached the Office of Internal Oversight and some deputies in Parliament, so I decided through the research to clarify the basis on which to rely on appropriate pumping systems to achieve the required operational conditions with the least energy expended And this reflected the choice of pumping systems that were chosen to work in Al -Faw oil depot. Through the research, it was found that the best way to choose oil pump systes and to save the energy used for pumping is to use the variable speed of the pump with the use of the parallel pumping system for multi pumps, which was used in the Faw oil depot.

Improving energy efficiency of individual centrifugal pump systems using model-free and on-line optimization methods

Pump systems around the world account for a high percentage of electrical energy consumption. The energy efficiency of these systems can be improved using control algorithms to determine appropriate operating points. The problem that arises is that computed operating points deviate from real operating points. This is due to deviations of the affinity laws, inaccurate information about pump characteristics, and plant behavior. In order to address this problem, we will present model-free optimization methods that can optimize various pump systems during ongoing operation. First, we will classify different pump systems. Based on this categorization, we will then analyze characteristic systems with regard to their energetic optimum. The resulting findings will enable us to identify suitable optimization algorithms. These model-free optimization algorithms take the form of an extremum seeking control in combination with a Kalman filter, the Nelder Mead algorithm, and a dynamic optimization method. After describing these algorithms, we will optimize and validate three sample classes of pump systems using the respective appropriate optimization strategy. The three classes represent a single-pump system, a multiple parallel pump system and a pump storage system. We can see that all optimization strategies achieve the energetic optimum. We can identify savings of between 7.9% and 50%, depending on the system in question. Finally, we will present a best-fit model-free optimization strategy for each class, and system operators can employ this strategy to ensure energy-optimized operation of their specific system.

Improving Reliability of Pumps in Parallel Pump Systems Using Particle Swam Optimization Approach

Parallel pump systems are widely used in industries. However, pumps are often operating under off-design conditions due to many reasons, which reduces the efficiency and reliability of the pumps. This paper aims at reducing the power consumption of parallel pump systems and improving the reliability of pumps by improving the operation points of pumps. To achieve this goal, a combination of selecting the proper number of pumps to put into operation and their speed is needed. Also, a control valve is adopted to further improve the operation points. The optimization model is built for a parallel pump system. Particle swarm optimization algorithm is used to solve the problem. Experimental verification shows that the proposed method improves the reliability and can also reduce power consumption for some cases compared to conventional PID speed regulation method. But for cases with large flow, extra power might be needed because the control valve introduces extra flow resistance in order to improve the operation point. The proposed method can be easily extended to applications based on their requirements on reliability.

Experimental Investigation of Power Signatures for Cavitation and Water Hammer in an Industrial Parallel Pumping System

Among the total energy consumption by utilities, pumping systems contribute 30%. It is evident that a tremendous energy saving potential is achievable by improving the energy efficiency and reducing faults in the pumping system. Thus, optimal operation of centrifugal pumps throughout the operating region is desired for improved energy efficiency and extended lifetime of the pumping system. The major harmful operations in centrifugal pumps include cavitation and water hammering. The pump faults are simulated in a real-time experimental setup and the operating point of the pump is estimated correspondingly. In this article, the experimental power quality and vibration measurements of cascade pumps during cavitation and water hammering is recorded for different operating conditions. The results are compared with the normal operating conditions of the pumping system for fault prediction and parameter estimation in a cascade water pumping system. Moreover, the Fast Fourier Transform (FFT) analysis comparison of normal and water hammering (faulty condition) highlights the frequency response of the pumping system. Also, the various power quality issues, i.e., voltage, current, total harmonic distortion, power factor, and active, reactive, and apparent power for a cascade multipump control is discussed in this article. The vibration, FFT, and various power quality measurements serve as input data for the classification of faulty pump operating condition in contrast with the normal operation of pumping system.

Power Quality Performance Analysis of grid tied PV fed Parallel Pumping System under Normal and Vibrating Condition

The aim of this paper is to perform the relative study of power quality problems in a grid tied solar PV system, with and without vibration connected to a parallel pumping system at 1.0 bar set pressure by using two control techniques such as VVC+ & V/f. In case of vibrations, the effect of motor vibration problems on the dynamic performance and electrical power quality of water pumping system will be observed. Vibrations are introduced in the pumping system by loosening the base plate of the pumps. During motor vibrations, the instantaneous flicker values become high which leads to variation in the supply voltage and torque imbalance. The effect of power quality parameters in a solar feeder during normal conditions and vibrating conditions are analysed. In normal condition, the THD increases and the flicker is high only during transient period due to sudden voltage variations. A comparison has been made to observe the appropriate control method for pumping system with and without vibrations in a solar PV-grid connected system.

Investigations of power quality disturbances in a variable speed parallel pumping system with grid tied solar PV

Energy use in water supply systems represents a significant portion of the global energy consumption. The electricity consumption due to the water pumping represents the highest proportion of the energy costs in these systems. The main objective of this paper is to observe the different power quality issues generated at the point of common coupling of a grid tied PV supplying power to the pumping motor for different preset pressures and taking readings at different loading conditions. The obtained results have been analyzed and valid conclusion is made on various power quality issue parameters like harmonics, voltage sag or swells levels etc. At the end suitable mitigation techniques to solve the PQ issues in a grid tied PV has been proposed.

Real time simulation of Variable Speed Parallel Pumping system

Energy is the world’s fundamental requirement to perform any work. Presently, insufficiency in energy is the major challenge faced throughout the world. Among the total installed loads, pumping contributes, 30% of them. Thus considerable improvement in energy savings is possible by increasing the energy efficiency of the pumping system. Nowadays, the usage of variable frequency drives (VFDs) for pumping system is becoming inevitable due to their control over flow rate variation. This paper presents the performance of real time simulated variable speed multi pumping system. The variable speed pumps using affinity laws reduces power up to 80% when there is a reduction in speed of 50%. The efficiency of the pumping system is identified by incorporating the efficiency of both motor and the variable frequency drive (VFD).

Optimization Research of Parallel Pump System for Improving Energy Efficiency

AbstractIn applications where demand on a water supply system changes frequently and widely, the operating conditions of pumps always deviate from the design conditions, and this error leads to poor efficiency and reliability. For energy saving and longer service life, a parallel pump system was supplied, with the valves and rotational speed controls approximating the system’s operating conditions closer to the designed conditions for different consumer loads. The developed optimization model employs a genetic algorithm (GA) aiming at the pumps’ maximum efficiency. A theoretical solution based on the Lagrange multiples method was proved. Experiments on two identical pumps were carried out. The presented model gives optimal input data for the pumps’ rotational speed and valve positions. The results show that control valves are especially helpful for improvement of a single pump’s efficiency and reliability. However, in the system of parallel pumps, throttling losses in the valves caused a significant decli...

VSD – control in simulated systems

To reduce the energy consumption of a parallel pumping system the whole pumping process and its components must be monitored. Simulated environments can be used in finding energy saving potential, which could be realized with different technical solutions such as VSD installment or changing speed adjustment methods.

Providing flow measurement in parallel pumping systems from variable speed drives

Monitoring what is happening inside the pump system is becoming more common with operators. Yet true flow rate characteristics are only as accurate as the data passed to the measurement program. In a controlled environment, Simo Hammo and Juha Viholainen studied the flow measurement function of the ABB industrial drive for pump control using a parallel pumping system. The results show a reasonably accurate flow rate for each pump as well as a sum flow for parallel pump.

A New Drip‐Injection Irrigation System for Crop Salt Tolerance Evaluation

An irrigation system was developed for the establishment of salinity gradients in field experiments that are aimed at obtaining salinity‐yield response functions of crops. The drip‐injection irrigation system (DIS) consists of a parallel pump system (a centrifugal pump for fresh water and an injection pump for saline water) and a conventional drip irrigation system composed of various irrigation sectors. The number of emitters installed in each irrigation sector determines the discharge of the centrifugal pump that blends with the fixed discharge of the injection pump. So, for the rest of fixed variables, the number of emitters (N) installed in a given irrigation sector determines the salinity of the irrigation water (ECiw): , with a measured coefficient of determination of ≈99%. The DIS was validated in an experiment where the salinity‐yield response functions of ten barley cultivars were obtained using nine ECiw salinity treatments, with two replications per treatment. The DIS proved to be accurate and robust in that: (i) the measured ECiw gradient was similar to the target ECiw gradient (r positively correlated at P < 0.0001); (ii) the soil salinity (ECe) horizontal and vertical (0–50 cm depth) uniformities within each salinity treatment were low (average coefficient of variation [CV] of the pooled salinity treatments equal to 16–22% for the horizontal soil salinity and equal to 10% for the vertical soil salinity) and the temporal variability of soil salinity was low to moderate (average CV of the pooled salinity treatments equal to 18% during the studied period); and (iii) ECiw and ECe were positively correlated (P < 0.001). We concluded that the DIS is an excellent, low cost irrigation system for conducting field crop salt tolerance evaluations.