Challenging Hypers Performance

2013 ◽  
Author(s):  
Enzo Giacomelli
Keyword(s):  
Failure Modes ◽  
Minimum Energy ◽  
High Capacity ◽  
Pressure Vessels ◽  
Diagnostic Systems ◽  
Minimum Energy Consumption ◽  
Process Gas ◽  
Starting Point ◽  
High Fatigue ◽  
Shrink Fitting

The production of LDPE may require huge heavy-duty reciprocating compressors to withstand the loads, deriving from the operating pressures, to satisfy the growing needs of the market. Safety, Performance and Reliability are normal expectations and therefore need a thorough evaluation of the specific service. The machine selection is based on positive experience in similar applications and cylinder performance. The cylinders are special pressure vessels, whose design and construction have to consider the extreme internal pressures and the process gas. The design must foresee all possible failure modes of each component, to have safe and smooth operation, thanks to innovative methods of modeling and simulation, like FEM and CFD, important for the design of cylinder parts. Valves are simulated by mathematical models optimizing performance, to reach a correct mechanical behavior with minimum energy consumption and ensuring reliable operation. The available technological improvements are a starting point, resulting from the developments of manufacturers and long experience of End Users. The pulsation and vibration of the piping are usually investigated to keep the plant in operation without failures. Many cylinder components are exposed to pressures fluctuating between suction and discharge and therefore to high fatigue loads. To reach high endurance capabilities they have to be pre-compressed to keep them operating under compressive stresses whenever possible. Special materials, shrink fitting and auto-frettage procedures are usually required. The operation is the stage where all the parameters have to be kept under control and incipient problems have to be identified to minimize shut-downs and arrange various maintenance works. Automation, monitoring and diagnostic systems complete the efforts of operators to afford high safety levels, with increased availability and optimized maintenance interventions. The continuing development of technology will help to challenge performance and high capacity demand of future plants.

Considerations on Design, Operation and Performance of Hypercompressors

2010 ◽  
Author(s):  
Enzo Giacomelli ◽  
Jun-Xia Shi ◽  
Fabio Manfrone
Keyword(s):  
Failure Modes ◽  
Minimum Energy ◽  
Pressure Vessels ◽  
Diagnostic Systems ◽  
Minimum Energy Consumption ◽  
Performance Requirements ◽  
Process Gas ◽  
Automation Systems ◽  
High Fatigue ◽  
And Performance

The production of LDPE may require huge power, heavy-duty reciprocating compressors, provided with opposite cylinders and special frames to withstand the loads, deriving from the operating pressures. In many new projects larger capacities and higher performance requirements, renew the challenge of engineers to handle the mechanical, thermodynamic, chemical-physical, process and operational aspects. Safety, performance, operation and reliability are usual expectations needing a thorough evaluation of the service and the machine selection is based on positive results in similar applications. Valve, packing and cylinder performance is noticeably influenced by the design, operation and maintenance activities. The cylinders are compound pressure vessels, excluded by design codes, but their design and construction have to consider the extreme internal pressures and the nature of the process gas. The ability to withstand the high fatigue stresses and the need to avoid any leakage of gas around the compressor area implies solutions to minimize such occurrences including abnormal operations and emergencies. The design must foresee all possible failure modes of each component, to have safe and smooth operation. Innovative methods of simulation and modeling, like FEA, CFD, and others, are very important tools for the design of cylinder components. Valves are simulated by mathematical models optimizing performance and ensuring reliable operation, to reach a correct mechanical behavior with minimum energy consumption. The available technological improvements are taken as a base, resulting from the R&D of manufacturers and long experience of End Users. Also the pulsation and related vibration of the piping have to be investigated to keep the plant in operation without hazard. The operation is the stage where all the parameters have to be kept under control and incipient problems have to be identified to minimize shut down and arrange various maintenance works. Automation systems, together with new monitoring and diagnostic systems, allow very high safety levels, availability and optimized maintenance interventions.

Safety Aspects of Design of Cylinders and Hyper-Compressors for LDPE

2004 ◽  
Author(s):  
Enzo Giacomelli ◽  
Paolo Battagli ◽  
Fabrizio Lumachi ◽  
Luciano Gimignani
Keyword(s):  
Failure Modes ◽  
Pressure Vessels ◽  
Diagnostic Systems ◽  
Safe Operation ◽  
Innovative Methods ◽  
Process Gas ◽  
Internal Pressures ◽  
Important Design ◽  
Very High ◽  
Design Aspect

The cylinders of reciprocating compressors for low-density polyethylene are compound pressure vessels, although generally excluded by Pressure Vessels design codes. Safety is the most important design aspect to be taken into account, because of the very high loads, the extreme internal pressures and the nature of the process gas. The design must evaluate from the safety standpoint all possible failure modes of each component, so that the machine is absolutely safe, notwithstanding the highly severe working conditions. The means to allow a smooth and safe operation of the compressor is the control of overpressure and overloading. The use of innovative methods of simulation and modelling, together with new diagnostic systems with special features, allow very high safety levels, high availability and optimised maintenance procedures.

Simulation of Cylinder Valves for Reciprocating Compressors

2006 ◽  
Author(s):  
Enzo Giacomelli ◽  
Fabio Falciani ◽  
Guido Volterrani ◽  
Riccardo Fani ◽  
Leonardo Galli
Keyword(s):  
Minimum Energy ◽  
Mechanical Valve ◽  
Pressure Vessels ◽  
Point Of View ◽  
Operating Conditions ◽  
Piping System ◽  
Minimum Energy Consumption ◽  
Cfd Models ◽  
Compression Cycle ◽  
Variable Operating Conditions

Advanced mathematical models are now used to simulate reciprocating compressors and particularly the cylinder valves. The valves represent the most critical component of these machines and need particular attention from the technology point of view. In addition, the potential variable operating conditions must be properly addressed and investigated. The pulsations generated by the compressor and piping system can have a critical impact on valve behavior. Therefore for complex situations a simulation of the complete system including pressure vessels and piping can be performed. The results of the programs include displacement, pressure drop, compression cycle, and pressure pulsations based on coefficients obtained experimentally and through advanced CFD models. Through simulation an optimum compromise between mechanical valve behavior and minimum energy consumption can be found.

Dimensioning a recovery boiler furnace using mathematical optimization

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 119-129 ◽  
Author(s):  
VILJAMI MAAKALA ◽  
PASI MIIKKULAINEN
Keyword(s):  
Radial Basis Function Network ◽  
High Capacity ◽  
Mathematical Optimization ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Performance Criteria ◽  
Boiler Furnace ◽  
Starting Point ◽  
Recovery Boiler ◽  
Base Design

Capacities of the largest new recovery boilers are steadily rising, and there is every reason to expect this trend to continue. However, the furnace designs for these large boilers have not been optimized and, in general, are based on semiheuristic rules and experience with smaller boilers. We present a multiobjective optimization code suitable for diverse optimization tasks and use it to dimension a high-capacity recovery boiler furnace. The objective was to find the furnace dimensions (width, depth, and height) that optimize eight performance criteria while satisfying additional inequality constraints. The optimization procedure was carried out in a fully automatic manner by means of the code, which is based on a genetic algorithm optimization method and a radial basis function network surrogate model. The code was coupled with a recovery boiler furnace computational fluid dynamics model that was used to obtain performance information on the individual furnace designs considered. The optimization code found numerous furnace geometries that deliver better performance than the base design, which was taken as a starting point. We propose one of these as a better design for the high-capacity recovery boiler. In particular, the proposed design reduces the number of liquor particles landing on the walls by 37%, the average carbon monoxide (CO) content at nose level by 81%, and the regions of high CO content at nose level by 78% from the values obtained with the base design. We show that optimizing the furnace design can significantly improve recovery boiler performance.

EUCOR: An Efficient Unequal Clustering and Optimal Routing in wireless sensor networks for energy conservation

2021 ◽  
pp. 1-9
Author(s):  
C. Jothikumar ◽  
Revathi Venkataraman ◽  
T. Sai Raj ◽  
J. Selvin Paul Peter ◽  
T.Y.J. Nagamalleswari
Keyword(s):  
Objective Function ◽  
Physical Phenomenon ◽  
Minimum Energy ◽  
Cluster Head ◽  
Industrial Applications ◽  
Base Station ◽  
Wireless Sensor ◽  
Unequal Clustering ◽  
Minimum Energy Consumption ◽  
Variable Cluster

Wireless sensor network is a wide network that works as a cutting edge model in industrial applications. The sensor application is mostly used for high security systems that provide safety support to the environment. The sensor system senses the physical phenomenon, processes the input signal and communicates with the base station through its neighbors. Energy is the most important criterion to support a live network for long hours. In the proposed system, the EUCOR (Efficient Unequal Clustering and Optimized Routing) protocol uses the objective function to identify the efficient cluster head with variable cluster size. The computation of the objective function deals with the ant colony approach for minimum energy consumption and the varying size of the cluster in each cycle is calculated based on the competition radius. The system prolongs the lifespan of the nodes by minimizing the utilization of energy in the transmission of packets in the networks when compared with the existing system.

scholarly journals Influence of Tool Geometry and Process Parameters on the Properties of Friction Stir Spot Welded Multiple (AA 5754 H111) Aluminium Sheets

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1157
Author(s):  
Danka Labus Zlatanovic ◽  
Sebastian Balos ◽  
Jean Pierre Bergmann ◽  
Stefan Rasche ◽  
Milan Pecanac ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Spot Welding ◽  
Minimum Energy ◽  
Tool Geometry ◽  
Friction Stir ◽  
Minimum Energy Consumption ◽  
Punch Test ◽  
Wide Range ◽  
Lap Welding

Friction stir spot welding is an emerging spot-welding technology that offers opportunities for joining a wide range of materials with minimum energy consumption. To increase productivity, the present work addresses production challenges and aims to find solutions for the lap-welding of multiple ultrathin sheets with maximum productivity. Two convex tools with different edge radii were used to weld four ultrathin sheets of AA5754-H111 alloy each with 0.3 mm thickness. To understand the influence of tool geometries and process parameters, coefficient of friction (CoF), microstructure and mechanical properties obtained with the Vickers microhardness test and the small punch test were analysed. A scanning acoustic microscope was used to assess weld quality. It was found that the increase of tool radius from 15 to 22.5 mm reduced the dwell time by a factor of three. Samples welded with a specific tool were seen to have no delamination and improved mechanical properties due to longer stirring time. The rotational speed was found to be the most influential parameter in governing the weld shape, CoF, microstructure, microhardness and weld efficiency. Low rotational speeds caused a 14.4% and 12.8% improvement in joint efficiency compared to high rotational speeds for both tools used in this investigation.

scholarly journals Optimal Control of the Positional Electric Drive and Its Implementation

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Vladimir Dotsenko ◽  
Roman Prokudin ◽  
Alexander Litvinenko
Keyword(s):  
Optimal Control ◽  
Wind Turbine ◽  
Electric Drive ◽  
Minimum Energy ◽  
Air Gap ◽  
Synchronous Generators ◽  
Capacitor Discharge ◽  
Wind Speeds ◽  
Minimum Energy Consumption ◽  
Low Wind Speeds

The article deals with the optimal control of the positional electric drive of the stator element of a segment-type wind turbine. The calculation options charts current in the assumption of the minimum energy consumption and the implementation of line chart current using the phenomenon of capacitor discharge. The analysis of the implementation is expressed in a jump-like change in current and a triangular graph of the speed change. This article deals with small capacity synchronous wind turbine generators with a segment type stator. These units have the possibility of intentionally changing the air gap between the rotor and stator. This allows: (1) Reduce the starting torque on the rotor shaft, which will allow the rotor to pick up at low wind speeds. (2) Equivalent to change of air gap in this case is change of excitation of synchronous generators. Thus, the purpose of the article is to consider a method of excitation of generators in a segmented design, by controlling the gap with the electric drive, while providing control should be carried out with minimal losses.

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