Selection of Nanostructured Zirconium Dioxide Crystals under Dry Friction against Molybdenum

The article considers the issues of contact interaction of nanostructured zirconium dioxide crystals with molybdenum coating on titanium-based alloy ВТ9. The following statement is substantiated: the best mechanical properties of crystals correspond to the total amount of 2.8% additives of stabilizing and doping rare earths elements. Antifriction properties of crystals under dry friction against molybdenum are investigated. Tribological testing was performed on a reciprocating friction gauge simulating the operation of a plunger in a cylinder. The high scoring resistance of the friction couple under study was experimentally proved; the friction coefficient did not exceed 0.07. On the basis of the study performed, the friction couple is defined as promising for increasing the lifetime and reliability of friction units for hydraulic equipment and fuel pumps.

Performance improvement methods of hydroficated machine under refrigeration

In this paper, the problem of the influence of climatic conditions on the performance of a Hydraulic gear is considered. The importance of the work is due to the fact that the methods for solving the problem are proposed, namely, the use of preheating for a Hydraulic gear and an internal combustion engine under refrigeration. The use of hydrofected self-propelled vehicles in the northern regions in winter is considered. The factors determining the technical and economic indicators of hydrofected machines are revealed. The influence of negative temperature on the physical and mechanical properties of hydraulic equipment materials is also considered. Three main directions have been identified in which temperature affects the hydraulic drive. An experiment was conducted in which the dependence of the performance of the machine was revealed using a preheating device for the working fluid and without the device.

Influence of temperature fluctuation on friction inside hydraulic cylinder

This paper considers variety of hydraulic actuators. Also it shows analysis of hydraulic equipment. The contribution is important due to the fact that it determines influence of temperature on friction in hydraulic equipment. The paper examines the factors of reducing the performance of hydrofected machines during operation at low temperatures. The importance of the work is due to the fact that the effects of temperature on friction in hydraulic equipment are considered. An experiment was also conducted, due to which the influence of temperature on the wear resistance of the hydraulic cylinder was revealed.

Improving the efficiency of manipulator-type machines with an improved hydraulic drive

The article considers the possibility of increasing the efficiency of manipulator-type machines when harvesting wood by increasing the productivity, energy efficiency and reliability of the hydraulic equipment used. A combined method of transporting timber from logging sites by road and water transport using equipment with an improved hydraulic drive of the manipulator is proposed. The issue has not been worked through before. Using the example of the Northwestern Federal District, the author considers the development of forest areas located in the upper reaches of small and medium rivers. For the first time, original hydromechanical dampers and energy-saving devices are used in hydraulic drives of manipulators of forest machines to reduce dynamic loads and energy consumption for loading and unloading timber. This increases the efficiency of the use of manipulator-type machines, creating mobility, reducing equipment costs, the time spent waiting for unloading on sites for further rafting or shipment. The development of forest areas in a combined way will reduce capital investments for the construction of transport routes at the border of waterways by at least 3 times. All this will reduce the cost of harvesting in general and eliminate the use of additional loaders.

ABOUT AUTOMATION OF CONTROL AND DIAGNOSIS OF TECHNICAL STATE OF HYDRAULIC DRIVES OF INDUSTRIAL EQUIPMENT

The main tasks of automated control and diagnostics of the technical condition of hydraulic drives are formulated, criteria for assessing the technical condition of a hydraulic drive as a whole and its individual devices are considered, examples of test operating modes for hydraulic drives with a guide and proportional hydraulic equipment are given.

Timely diagnostics of hydraulic equipment in metallurgical production

Precision control of hydraulic equipment is a distinctive feature of modern hydraulic systems. With the help of special diagnostic devices, it is possible to reliably and simply monitor the operation of hydraulic equipment. Diagnostic methods can be very different. The article lists the stages and methods of checking hydraulic equipment malfunctions, as well as describes the principles of operation of diagnostic devices of well‑known world manufacturers HYDAC, MOOG, used in OJSC “BSW – Management Company of the Holding “BMC”. Schematically, the connection of the MOOG tester to the production equipment is presented when checking the servo valve in autonomous and combined mode, without resorting to dismantling the valve. Continuous monitoring of the oil purity with the help of the HYDAC FCU device allowed saving time on assessing its condition and taking fast‑acting corrective measures to clean the oil from contamination.

A Study of Moist Air Condensation Characteristics in a Transonic Flow System

When water vapor in moist air reaches supersaturation in a transonic flow system, non-equilibrium condensation forms a large number of droplets which may adversely affect the operation of some thermal-hydraulic equipment. For a better understanding of this non-equilibrium condensing phenomenon, a numerical model is applied to analyze moist air condensation in a transonic flow system by using the theory of nucleation and droplet growth. The Benson model is adopted to correct the liquid-plane surface tension equation for realistic results. The results show that the distributions of pressure, temperature and Mach number in moist air are significantly different from those in dry air. The dry air model exaggerates the Mach number by 19% and reduces both the pressure and the temperature by 34% at the nozzle exit as compared with the moist air model. At a Laval nozzle, for example, the nucleation rate, droplet number and condensation rate increase significantly with increasing relative humidity. The results also reveal the fact that the number of condensate droplets increases rapidly when moist air reaches 60% relative humidity. These findings provide a fundamental approach to account for the effect of condensate droplet formation on moist gas in a transonic flow system.

A new method of health condition detection for hydraulic pump using enhanced whale optimization-resonance-based sparse signal decomposition and modified hierarchical amplitude-aware permutation entropy

The normal operation of the hydraulic pump is the significant premise for the stable and dependable working of hydraulic equipment. Consequently, this research comes up with a health condition detection method of hydraulic pump. First of all, this approach selects resonance-based sparse signal decomposition (RSDD) to adaptively disintegrate vibration signals. The biggest problem of the RSDD algorithm is the requirement to artificially set a large number of key parameters, such as quality factor Q, weight coefficient A, and Lagrange operator u. The improper parameter settings will seriously affect the decomposition performance. To overcome this shortcoming, an enhanced whale optimization algorithm is presented to search the best parameter combination of the RSDD. The algorithm takes the correlation kurtosis as the optimization objective function to adaptively disintegrate the signal into low and high resonance components. Moreover, on the basis of the modified analytic hierarchy process and the amplitude-aware permutation entropy, the modified hierarchical amplitude-aware permutation entropy is raised for measuring the complexity of the measured time series more accurately and comprehensively. After that, a health condition detection method for hydraulic pump based on enhanced whale optimization-resonance-based sparse signal decomposition and modified hierarchical amplitude-aware permutation entropy is raised. Finally, through the usage of the hydraulic pump vibration data, this method is compared with other approaches. According to the experimental results, the raised method can identify the fault type more effectively, which is capable of offering a feasible idea for the health condition detection of hydraulic equipment.

Hydraulic Modelling of Different Working Regimes in Water Pipeline. Case Study: Mihaliq – Water Treatment Plant “SHKABAJ”

In the flow through the pipes, we have unstable movements when, due to the closing or opening of the valve or other hydraulic equipment, the speed of movement of the liquid changes. The change in velocity causes inertial forces to arise in the liquid which cause pressure changes in the flow. The phenomenon characterized by these pressure changes is called hydraulic water hammer. The hydraulic shock can be called the increase or decrease of the flow pressure in the pipe caused by the change in time (in any section) of the flow velocity. The objective of this paper is to provide information and resources to assist water company management and their staff in identifying and implementing opportunities to reduce energy use. Case study is Pumping Station in Milloshevo managed by Regional Water Company “PRISHTINA”.