Combined Heat and Power Dynamic Economic Dispatch incorporating pumped hydro energy storage considering uncertainty and outage of renewable energy sources

Owing to increasing penetration of renewable energy sources, it is mandatory to investigate it’s effect on the combined heat and power dynamic economic dispatch. At the same time , adverse effect is there due to highly intermittent nature and higher rate of outages of these sources . This piece of work proposes squirrel search algorithm (SSA) for solving combined heat and power dynamic economic dispatch (CHPDED) incorporating pumped-storage-hydraulic unit captivating uncertainty and outage of renewable energy sources. A lately developed swarm intelligence algorithm SSA, emulates from the dynamic scavenging behavior of squirrel. The competence of the recommended technique is examined on a test system. Simulation outcomes of the proposed technique is harmonized with those acquired by particle swarm optimization (PSO) and grey wolf optimization (GWO). After comparison, a conclusion was made presenting SSA technique conferring with good-quality solution than other techniques.

Laboratory Modeling of an Axial Flow Micro Hydraulic Turbine

This article is devoted to detailed experimental studies of the flow behind the impeller of an air model of a propeller-type microhydroturbine in a wide range of operating parameters. The measurements of two component distributions of averaged velocities and pulsations for conditions from part load to strong overload are conducted. It is shown that the flow at the impeller outlet becomes swirled when the hydraulic turbine operating mode shifts from the optimum one. The character of the behavior of the integral swirl number, which determines the state of the swirled flow, is revealed. Information about the flow peculiarities can be used when adjusting the hydraulic unit mode to optimal conditions and developing recommendations to expand the hydraulic turbine operation control range with preservation of high efficiency. This stage will significantly save time at the stage of equipment design for specific field conditions of water resource.

A novel prognostics solution for machine tool sub-units: The hydraulic case

A novel prognostic approach was developed and applied to a machine tool hydraulic unit. Three components were considered: pump, sensor and valve. The proposed methodology exploited a digital twin of the system to perform simulations of the healthy and faulty machine. The digital twin was properly validated through experiments. This approach dealt with the need to carry out time-consuming and expensive experimental campaigns, that is, run-to-failures – not affordable in many industrial applications. The diagnosis module was trained on digital twin simulations and fulfilled the fault detection, isolation and quantification phases. The challenge related to the variability of the operating conditions of the machine was addressed through a robustness analysis of the methodology. The solution successfully dealt with both stationary and non-stationary working conditions. A dedicated classification model was designed for each faulty component, maximising the associated classification rate. The testing procedure consisted of the application of a 10-fold cross-validation to compute the mean classification rates for stationary and non-stationary working conditions. Diagnosis performance results were excellent for the pump, whereas they were lower for the sensor and valve, reaching 79.75% and 74.93% accuracy respectively for the most challenging working cycle. The prognosis directly exploited the output of diagnostics, allowing for experimental effort reduction. Prognosis predictions were built starting from the updated health status provided by the diagnosis output. In order to test the prognosis module, mean and standard deviation of the prediction errors (less than 1.176%) were computed through a Monte Carlo approach. The conceived methodology allowed one of the critical goals of prognostics to be handled: the Remaining Useful Life probability density function estimation.

Technology of welding and repair works of hydropower plants units

In the course of long-term operation of hydroelectric units, they are subject to wear and tear, which negatively affects the power generating capacity of the hydroelectric power station. The existing repair technology provides the restoration of the geometric dimensions of the impeller chamber of the hydraulic unit using an austenitic cladding layer. However, this technology is characterized by the occurrence of cracks and delamination of the deposited layer during post-repair operation, which is negatively reflected in the production cycle of electricity. A new technology and welding consumables have been proposed for repair and restoration works of hydroelectric units at hydroelectric power plants, providing an increase in the quality level, high characteristics of hydroabrasive and cavitation resistance, and increasing of working period of hydroelectric power plants. Inspection of the body of the hydraulic unit was carried out, defects were identified and classified, the reasons for their occurrence were analyzed. The research results make possible to optimize the alloying system of the deposited metal, to determine the optimal welding mode, to reduce the amount of the martensite component and to develop new filler materials and the technology for welding and repair works of hydroelectric power plants.

Dynamics control of powered hydraulic roof supports in the underground longwall mining complex

The study presents the dynamic analysis of the hydraulic cylinders operated in the powered roof support sections as an important part of the longwall underground mining complexes. This type of hydraulic unit is subjected to frequent shock impacts from the significant rock masses released on the top of mined caverns. Hydraulic props are equipped with safety valves with steel helical springs, which intend to reduce peak loads by the relief of internal pressure. These valves respond to shock with a time delay due to the limited velocity of the pressure wave inside the cylinder and an additional pipe of a small section, which restricts fluid flow in outer space. The new approach represented in this paper is based on mathematical modelling of the interaction of the hydraulic and mechanical parts and using additional signals to control safety valves. Detection of shock in advance (0.02-0.05 s) allows reducing pressure peaks by 30% and avoid failures. The challenges are the development of a “smart valve” with optimised control functions by the signals from additional sensors (vibration, deformation, piston position) and providing fast reaction time with a high flow rate under pressures up to 100 MPa.

Cyclic Production Scheme for High WC and Low-Pressure Wells for Reservoir Management

Lower Burgan (LB) is one of the most mature reservoirs in north Kuwait divided in to 3 layers, first layer under partial depletion drive and suffer from low reservoir pressure, the second layer under edge-partial water drive and the last layer under active water drive. Increasing trend of water production and high GOR has become a big challenge to control the reservoir production, several of studies done to evaluate the best strategy to enhance the reservoir performance. A comprehensive review of the performance of the wells was conducted to diagnose the specific reason and necessary remedial measures to be adopted. The review included the assessment of the results of the material balance and numerical simulation studies, depletion strategies, wettability/ relative permeability footprints; proximity to the OWC; past completion practices, well integrity and the time lapse PNC/PLT/ Well testing data. Workflows were developed for the sublayers within the hydraulic unit for systematic water cut diagnostics and preventive steps. Identification of suitable technology to address water cut and GOR management was also done. The typical trend of water cut and GOR performance with time and the depletion strategy was established to add value to the ongoing production activities and well allowable for each hydraulic unit. Rate sensitive performance was analyzed for the integration into the production plans. Cyclic production is identified as one of the new ways to reduce the water production and maintain the production for the wells producing below the bubble point. The concept was tried at high water cut wells successfully to revive the well from about 100% to 87% water cut with a closure cycle for 3 month and sustaining the production for high GOR wells with good ESP performance. In addition, suitable candidates have been identified for Coning Control Completions to weaken the water encroachment into the downhole wellbore. The overall water cut for the reservoir has been stabilized during last one year, thus helping the water handling constraints at the gathering facility. This paper will discuss the successful approach to control coning and water encroachment for active Bottom and Edge-Water drive layer and how this approached helped to sustain the production on high GOR wells running below bubble point with necessary diagnostics and remedial measures.

Comparative study: Impact of Ball burnishing and shot peening Process on Aluminium 2024 alloy

Compressive residual stress is the major aspect in the extension of the fatigue life of aeroengine components. In this study, a modified burnishing surface treatment and conventional shot peening process was used was proposed to improve surface integrity characteristics such as surface finish, hardness, and stable, advantageous compressive residual stress in turned Cylindrical Aluminum 2024Specimen. In burnishing process, a rolling rigid spherical HSS ball is pressed across an Aluminum 2024Specimen under definite fluid pressure generated by the hydraulic unit and also shot peening was carried out at a shot velocity of 300 m/s. This research examined the effect of burnishing treatment and shot peening process on beneficial compressive residual stresses.