The problem addressed in this paper focuses on the reduction of electrical energy costs for the operation of hydraulic pumps, which are used for catchment and distribution of water in water supply ...systems. As the electricity tariffs are different according to the time of day, it is necessary to decide when and how many pumps must be used to collect and distribute water, in each period of time, and, when there must be water transfer among tanks so that the demand of each consumer center is met without a lack of resources. A mixed integer programming (MIP) model is proposed and a competitive MIP‐based heuristic is developed to solve this problem. Numerical tests in a case study carried out with the water supply system of a Brazilian city demonstrate the efficiency of the proposed mathematical model and solution method.
Pump and motor efficiency is a complex subject, to such an extent that most of the available models describing efficiency today rely on experimental data. In spite of that, mathematical models ...relating efficiency to pressure and angular speed have been proposed throughout the years. In all these models, volumetric and mechanical efficiencies are separately built from flow and torque losses relations. The overall efficiency model is then obtained by multiplying the volumetric and the mechanical efficiency equations. In this paper, we show that the overall efficiency equations must be developed from an energy balance and show that the simple multiplication of mechanical and volumetric efficiencies can potentially lead to inaccurate results. We then obtain a generalised equation relating the overall efficiency to pressure and angular speed for both pumps and motors and show how the resulting model can be fitted to actual experimental data.
This article presents a novel fluid structure interaction (FSI) model for lateral lubricating interfaces in an asymmetrically balanced external gear pump. Due to the asymmetry in the geometry of the ...floating lateral bushes responsible for sealing the displacement chambers in such machines, the lubricating interfaces on either side of the gears have been modeled as distinct but coupled lubricating films. An elastohydrodynamic (EHD) lubrication regime was modeled in all simulations and film thickness predictions for both lubricating interfaces have been achieved. The novel FSI model for the asymmetric lateral gaps is then used in an automatic optimization procedure to design the optimal axial balance in the reference external gear machine (EGM). The optimal axial balance is achieved by determining the optimal balance area on the lateral bush by considering specific design variables associated with it. The procedure aims to find the best feasible design solution that minimizes the total power losses in the lubricating interfaces while also minimizing the nonuniformities in the orientation of these gaps between two significant operating conditions of the EGM. The developed procedure highlights the potential to virtually design the axial balance in EGMs-which represent a key design aspect of pressure compensated EGM-by using an advanced FSI-EHD model.
The present paper introduces the creation of an algorithm and the software used to determine the energetic performance and monitor the efficiency of hydraulic pumps working in various industrial ...applications, such as water supply systems, water treatment processes, and irrigation systems, particularly in the cases where there is no permanent monitoring. Our field investigations and the surveyed literature show that the only parameter that is neither monitored nor computed is the efficiency of the pumps. The software implementation allows for determining the in-service efficiency of the pumps and comparing it to the value associated with the best efficiency point (BEP). The solution is user-friendly and can be easily installed on any computer or smartphone. The software has been applied and tested in the Hydraulic Machines Laboratory at the “Politehnica” University Timişoara and at the AQUATIM S.A. regional water supply company. The software module monitors the operating regimes of the pumps and supports the deployment of predictive maintenance and servicing.
A new clearance design method is proposed for a reciprocating fuel pump. Structural and hydrodynamic lubrication analyses were conducted to design the clearance of the pump, and the former was used ...to evaluate the clearance reduction due to the deformation that results from applying maximum supply pressure. The reduction in the maximum clearance was used as the limit of the design, and the two-dimensional Reynolds equation is used to evaluate the lubrication characteristics of the pump with variations in the viscosity and clearance. The optimal clearance in the pump must be separately designed in both the stem and the head because the lubrication characteristics and the deformation patterns of the two parts are different. The validity of the numerical model was then verified by determining that the position of the wear was also similar to that of the minimum film thickness. Moreover, a rig test system was also used to verify the clearance of the proposed design method.
The use of ultrahigh-molecular-weight polyethylene (UHMWPE) in manufacturing is proposed—in particular, for the cuffs of hydraulic drives. The properties of UHMWPE are considered, in comparison with ...other types of polyethylene.
Mechatronics is one of rapidly developing spheres of world machinery and science. In many cases its quality depends on drive unit quality. Sensitivity and efficiency of a hydraulic drive unit are ...mostly determined by hydraulic machines parameters. For the reasons set out an axial-piston swash plate pump with reduced friction forces was designed. Present work describes the method of computation of the basic parameters of piston--cylinder bore mechanism that provide operability and improved characteristics of the developed axial-piston swash plate pump, and an experimental proof of this computation. The research object is an axial-piston swash plate pump with full hydrostatic slipper bearing. As a result of the preliminary tests of the piston--cylinder bore mechanism of the swash plate pump operational and structural restrictions, which influence the interfaces between pump's elements, were found. Thereby an additional force analysis was performed, applied relations were obtained, which lead to detection of the developed pump swash plate angle range that provides its operability and improved dynamic and energy characteristics. The conditions of operability of the developed pump were found. An appliance of the present hydraulic machine allows reducing friction forces and significantly improving characteristics of the whole mechatronic system. Keywords: swash plate pump; machinery; hydraulics; mechatronics; drive unit
In view of the existing electrical vibration monitoring traditional hydraulic pump vibration sensor, the high false alarm rate is susceptible to electromagnetic interference and is not easy to ...achieve long-term reliable monitoring, based on the design of a beam of the uniform strength structure of the fiber Bragg grating （FBG） vibration sensor. In this paper, based on the analysis of the vibration theory of the equal strength beam, the principle of FBG vibration tuning based on the equal intensity beam is derived. According to the practical application of the project, the structural dimensions of the equal strength beam are determined, and the optimization design of the vibrator is carried out. The finite element analysis of the sensor is carried out by ANSYS, and the first order resonant frequency is 94.739 Hz. The vibration test of the sensor is carried out by using the vibration frequency of 35 Hz and the vibration source of 50 Hz. The time domain and frequency domain analysis results of test data show that the sensor has good dynamic response characteristics, which can realize the accurate monitoring of the vibration frequency and meet the special requirements of vibration monitoring of hydraulic pump under specific environment.
Regenerative flow pumps are kinds of dynamic pumps with the ability to develop high heads at low flow rates. Despite the disadvantage of having low hydraulic efficiency, regenerative flow pumps have ...found many applications in industries. In this paper, the effect of fluid viscosity on the performance of regenerative pump has been investigated experimentally. The primary fluid was water with viscosity of 1 centipoise. Polyacrylamide (PAM) which is a soluble polymer in water was used to increase the viscosity of fluid. Solutions prepared from dry powder PAM at two concentrations of 1600 ppm and 2400 ppm. Solutions were pumped more than 30 times to have homogeneous fluids. The measured viscosities for these two solutions were 180 and 300 centipoises respectively. Results showed that as flow coefficient reduces, the decline in head coefficient gradually increases. Similarly, it was found that viscosity enhancement reduces the power coefficient. There was not any significant change in efficiency curves at low flow coefficients. In contrast, around design flow coefficient and at high flow coefficients, the hydraulic efficiency of the pump reduced by increasing viscosity of working fluid.
The article describes the materials on the development of intelligent algorithms, hardware and software configuration of information-measuring system that automates the stand for the operational life ...testing of hydraulic machines - oil sediment and motors. The cRIO was selected as a basic hardware platform with a set of input-output modules interacting with a personal computer via Ethernet interface to start the test and display the results. The intelligence of the system is provided by the implementation of artificial neural networks that analyze the stand values and make decisions on its operation.
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