Search

The article analyzes results of hydrodynamic research the well and of technological mode of their work. The analysis revealed a certain regularity technological mode - fitting diameter is usually more than the max- imum diameter of the fitting at the hydrodynamic research. The Provides examples of calculation the coeffi- cient of resistance connecting according to data studies wells at the field White Tiger.

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coastal areas are particularly vulnerable to flooding from heavy rainfall, sea storm surge, or a combination of the two. Recent studies project higher intensity and frequency of heavy rains, and progressive sea level rise continuing over the next decades. Pre-emptive and optimal flood defense policies that adaptively address climate change are needed. However, future climate projections have significant uncertainty due to multiple factors: (a) future CO2 emission scenarios; (b) uncertainties in climate modelling; (c) discount factor changes due to market fluctuations; (d) uncertain migration and population growth dynamics. Here, a methodology is proposed to identify the optimal design and timing of flood defense structures in which uncertainties in 21st century climate projections are explicitly considered probabilistically. A multi-objective optimization model is developed to minimize both the cost of the flood defence infrastructure system and the flooding hydraulic risk expressed by Expected Annual Damage (EAD). The decision variables of the multi-objective optimization problem are the size of defence system and the timing of implementation. The model accounts for the joint probability density functions of extreme rainfall, storm surge and sea level rise, as well as the damages, which are determined dynamically by the defence system state considering the probability and consequences of system failure, using a water depth–damage curve related to the land use (Corine Land Cover); water depth due to flooding are calculated by hydraulic model. A new dominant sorting genetic algorithm (NSGAII) is used to solve the multi-objective problem optimization. A case study is presented for the Pontina Plain (Lazio Italy), a coastal region, originally a swamp reclaimed about a hundred years ago, that is rich in urban centers and farms. A set of optimal adaptation policies, quantifying size and timing of flood defence constructions for different climate scenarios and belonging to the Pareto curve obtained by the NSGAII are identified for such a case study to mitigate the risk of flooding and to aid decision makers. [ABSTRACT FROM AUTHOR]

California’s energy crisis in 2001 resulted in a state-funded program for testing irrigation pumps and improving pumping plant efficiency, with the goal of reducing energy use in California agriculture. Yet in reality, improving pumping plant efficiency may not actually translate into savings. To reduce electrical energy use, the kilowatt-hours must decrease because of fewer kilowatts or less operating time, or both. In order to evaluate the efficiency of various energy-improving adjustments, we studied several operations at pumping plants in the San Joaquin Valley. These included adjusting impellers, repairing worn pumps, replacing mismatched pumps and using more energy-efficient motors. We found that adjusting or repairing worn pumps may actually increase energy use, unless the operating time of the pumping plant is reduced. Multiple pump tests of a pumping plant are recommended, to help evaluate possible reasons for low efficiency. Pumping plant operators should also obtain the manufacturer’s performance curves to use in the evaluation process.

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the past decades, China had rapid economic development accompanied by a large number of garbage production, eventually most of them converge in various rivers. In order to protect the normal operation of the pumping station, it is required that the trash rack of the pumping station can be cleaned in time. Due to the structural defects, the conventional rotary sewage interceptor and cleaning machine has low waste clean efficiency, high leakage rate of the waste and high failure rate of equipment, which affects the normal operation of the sewage interception and cleaning equipment and pumping station units. In order to improve the reliability and efficiency of the cleaning equipment, the structure of the conventional rotary sewage interceptor and cleaning machine is improved and optimized. The walking mode of the roller convex rail and the limit device are advanced on the rack traction chain to avoid the derailment of the chain and improve the positioning accuracy of the rack. On this basis, the rack bar section is changed from rectangle to diamond arrow type, and the rack teeth are changed from triangle to plate type. The plate tooth surface is supported by a triangular stiffened plate, and the tooth harrow pipe is changed from a circular pipe to a rectangular one, which enhances the load-carrying capacity of the single harrow tooth and the bending strength of the tooth harrow. It has been realized that the harrow teeth, the tooth harrow and the rack are precisely matched with each other, the adhesive blockage of the rack is reduced, the overload of harrow tooth and harrow pipe is avoided by cutting off the dragging weeds in front of the rack in the initial cleaning stage, and the broken accidents of harrow tooth and harrow tube are avoided, also. 2-3 pieces of split structure trash rack are used in the wide single-hole trash rack to facilitate the lifting, maintenance and replacement of the grid. Side dirt guide plates and bottom arc front rack are used to clean the trash accumulating at the pier beam and bottom of the rack and improve the trash-cleaning efficiency at the sides and bottom. The application results show that through structure improvement, the operation reliability and the trash-cleaning efficiency of the rotary sewage interceptor and cleaning machine has been improved, the equipment failure rate and maintenance cost has been reduced, the water level difference before and after the trash rack has been reduced also, and therefore, the operation reliability and the efficiency of the pump station have been improved. Compared with the conventional rotary sewage interceptor and cleaning machine, the improved rotary sewage interceptor and cleaning machine has higher reliability, increases the cleaning efficiency by more than 30%, reduces the average water level difference before and after the trash interception grid from 60 cm to less than 10 cm, and reduces the operation cost of the pumping station by about 184 thousand yuan. [ABSTRACT FROM AUTHOR]

Rising of the sea level and/or heavy rainfall intensification significantly enhance the risk of flooding in low-lying coastal reclamation areas. Therefore, there is a necessity to assess whether channel hydraulic networks and pumping systems are still efficient and reliable in managing risks of flooding in such areas in the future. This study addresses these issues for the pumping system of the Mazzocchio area, which is the most depressed area within the Pontina plain, a large reclamation region in the south of Lazio (Italy). For this area, in order to assess climate change impact, a novel methodological approach is proposed, based on the development of a simulation–optimization model, which combines a multiobjective evolutionary algorithm and a hydraulic model. For assigned extreme rainfall events and sea levels, the model calculates sets of Pareto optimal solutions which are obtained by defining two optimality criteria: (a) to minimize the flooding surface in the considered area; (b) to minimize the pumping power necessary to mitigate the flooding. The application shows that the carrying capacity of the hydraulic network downstream of the pumping system is insufficient to cope with future sea level rise and intensification of rainfall. [ABSTRACT FROM AUTHOR]