A Novel Method to Quickly Acquire the Energy Efficiency for Piston Pumps

Author(s):  
Mengdi Gao ◽  
Haihong Huang ◽  
Xinyu Li ◽  
Zhifeng Liu

The energy efficiency of the piston pumps is one of the considerable important factors in design and analysis of hydraulic system, especially in the process of real-time tracking of energy dissipation in a variety of loading conditions. The existing methods for obtaining the energy efficiency curve of piston pumps are either time-consuming or inaccurate. In order to quantify the energy efficiency of the piston pumps quickly and accurately, the leakage and friction energy loss caused by the clearances in the sliding pairs are analyzed, and an overall efficiency model was established, which contains two constants to be determined by two test points. The accuracy of the model was verified based on a test rig for a hydraulic pump, and it can be improved by selecting appropriate test points via the method of deviation analysis. The results show that the proposed efficiency models are in good agreement with the experimental results, and the best test points are in the range of 0–25% and 51–75% of the peak pressure of the investigated piston pump.

2014 ◽  
Vol 931-932 ◽  
pp. 403-407
Author(s):  
Weerapong Chanbua ◽  
Unnat Pinsopon

At the present time, researchers try to find alternative fluids for being used as lubricants or hydraulic fluids that are biodegradable and environmental friendly. In this study, Refined-Bleached-Deodorized (RBD) palm olein was investigated whether it is such a potential candidate. RBD palm olein could be easily acquired since it is of the type used as cooking oil. The physical properties of both conventional hydraulic oil and RBD palm olein were tested and compared by an accredited laboratory. The performance of the hydraulic systems when using both fluids as working mediums were also tested and compared. The experimental results show that temperature significantly affected the performance of the hydraulic system when using conventional hydraulic oil, whereas the performance of the hydraulic system when using RBD palm olein barely changed with temperatures. At the temperatures below 60 °C, the RBD palm olein yielded less flow rate and less energy efficiency. However, for the temperatures above 60 °C, the RBD palm olein yielded slightly more flow rate and slightly more energy efficiency. It can be confirmed from this study that RBD palm olein can be used as an alternative hydraulic fluid.


Energy ◽  
2021 ◽  
pp. 121112
Author(s):  
Siyuan Fan ◽  
Yu Wang ◽  
Shengxian Cao ◽  
Tianyi Sun ◽  
Peng Liu

Author(s):  
Niko Karlén ◽  
Tatiana Minav ◽  
Matti Pietola

Several types of off-road machinery, such as industrial trucks, forklifts, excavators, mobile cranes, and wheel loaders, are set to be operated in environments which can differ considerably from each other. This sets certain limits for both the drive transmissions and working hydraulics of these machines. The ambient temperature must be taken into account when selecting the hydraulic fluid since the viscosity and density of the fluid are changing at different operating temperatures. In addition to the temperature, energy efficiency can also be a problem in off-road machinery. In most off-road machines, diesel engines are employed to produce mechanical energy. However, there are energy losses during the working process, which causes inefficiency in produced energy. For better energy efficiency, hybridization in off-road machinery is an effective method to decrease fuel consumption and increase energy savings. One of the possible methods to save energy with hybrids is energy regeneration. However, it means that the basic hydraulic system inside off-road machinery needs to be modified. One solution for this is to utilize zonal or decentralized approach by means of direct driven hydraulic (DDH) system. This paper aims to investigate a DDH system for off-road machinery by means of modelling and analyzing the effect of the temperature. In the direct-driven hydraulic system, the actuator is controlled directly by the hydraulic pump which is operated by the electric motor. Specifically, it is a valveless closed-loop hydraulic system. Thus, there will be no energy losses caused by the valves, and the total efficiency is assumed to be significantly higher. In order to examine the DDH system, a thermo-hydraulic model was created. Additionally, a thermal camera was utilized in order to illustrate the temperature changes in the components of the DDH system. To reproduce the action of the system in different circumstances DDH system was run at different ambient temperatures, and the component temperatures in the system were measured and saved for the analysis. The thermo hydraulic model was proven capable to follow the general trend of heating up.


2021 ◽  
pp. 27-30
Author(s):  

An algorithm is proposed for calculating a closed volumetric hydraulic pump-hydraulic motor system using the example of the hydraulic system of a wind power plant, based on the calculation of the hydraulic systems of mobile machines. The main characteristics of the system components, the selection of initial data for the calculation, working fluid and diameters of hydraulic lines are analyzed. Keywords: hydraulic system, energy, fluid, oil, pump, motor, renewable energy source, wind power plant, machine. [email protected]


Author(s):  
Taehoon Kim ◽  
Sukyoung Pak ◽  
Yongjin Cho

During a severe accident, contact of the molten corium with the coolant water may cause an energetic steam explosion which is a rapid increase of explosive vaporization by transfer to the water of a significant part of the energy in the corium melt. This steam explosion has been considered as an adverse effect when the water is used to cool the molten corium and could threaten reactor vessel, reactor cavity, containment integrity. In this study, TROI TS-2 and TS-3 experiments as part of the OECD/SERENA-2 project were analyzed with TEXAS-V. Input parameters were based on actual TROI experiment data. In mixing simulations, calculated results were compared to melt front behavior, void fraction in trigger time and other parameters in experiment results. In explosion simulations, corresponding to TROI experiments an external triggering was employed at the moment that melt front reached heights of 0.4 m. Calculated results of peak pressure and impulse at the bottom were compared with TROI experiment results. Melt front behaviors of the melt was different from the experimental results in both TS-2 and TS-3. Void fraction in triggering time in TS-2 was in good agreement with the experiment results and in TS-3 was slightly overestimated. The peak pressure and impulse at bottom were successfully predicted by TEXAS-V. These calculations will allow establishing whether the limitations and differences observed in the simulations of the experiments are important for the reactor case.


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4460 ◽  
Author(s):  
Yunzhao Jia ◽  
Minqiang Xu ◽  
Rixin Wang

Hydraulic pump is a driving device of the hydraulic system, always working under harsh operating conditions, its fault diagnosis work is necessary for the smooth running of a hydraulic system. However, it is difficult to collect sufficient status information in practical operating processes. In order to achieve fault diagnosis with poor information, a novel fault diagnosis method that is the based on Symbolic Perceptually Important Point (SPIP) and Hidden Markov Model (HMM) is proposed. Perceptually important point technology is firstly imported into rotating machine fault diagnosis; it is applied to compress the original time-series into PIP series, which can depict the overall movement shape of original time series. The PIP series is transformed into symbolic series that will serve as feature series for HMM, Genetic Algorithm is used to optimize the symbolic space partition scheme. The Hidden Markov Model is then employed for fault classification. An experiment involves four operating conditions is applied to validate the proposed method. The results show that the fault classification accuracy of the proposed method reaches 99.625% when each testing sample only containing 250 points and the signal duration is 0.025 s. The proposed method could achieve good performance under poor information conditions.


Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 440 ◽  
Author(s):  
Huang ◽  
Yuan

A novel method to design a wideband substrate integrated waveguide (SIW) bandpass filter (BPF) with compact size, wide stopband and high selectivity is presented. In this method some unique electromagnetic band-gap (EBG) cells are periodically etched on the top layer of SIW to realize a wide passband propagating below the equivalent waveguide cutoff frequency. By changing the configuration of EBG cells, undesired harmonics in upper stopband can be suppressed and a wideband BPF with wide stopband can be obtained. By symmetrically loading two complementary split ring resonators (CSRRs) on the tapered gradient lines of the input/output ports, a transmission zero near the passband can be introduced, and it makes the frequency selectivity of upper sideband improve significantly. As a verification, a wideband SIW BPF with a 3.02 GHz absolute bandwidth (ABW) and a 64.7% fractional bandwidth (FBW) centered at 4.67 GHz is designed, simulated, manufactured, and measured. The results of the experiment and simulation are in good agreement.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Wei-Qiang Pan ◽  
Xiao-Lan Zhao ◽  
Yao Zhang ◽  
Jin-Xu Xu

This paper presents a novel method to design dual-band bandpass filters with tunable lower passband and fixed upper passband. It utilizes a trimode resonator with three controllable resonant modes. Discriminating coupling is used to suppress the unwanted mode to avoid the interference. Varactors are utilized to realize tunable responses. The bandwidth of the two bands can be controlled individually. Transmission zeros are generated near the passband edges, resulting in high selectivity. For demonstration, a tunable bandpass filter is implemented. Good agreement between the prediction and measurement validates the proposed method.


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