scholarly journals Analytical Approach to Sampling Estimation of Underwater Tunnels Using Mechanical Profiling Sonars

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1900
Author(s):  
Vitor Augusto Machado Jorge ◽  
Pedro Daniel de Cerqueira Gava ◽  
Juan Ramon Belchior de França Silva ◽  
Thais Mancilha ◽  
Waldir Vieira ◽  
...  

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.

2012 ◽  
Vol 2 (8) ◽  
pp. 1-9
Author(s):  
Saroj Koul

Subject area Operations and human resourcing. Study level/applicability This case study is intended for use in graduate, executive level management and doctoral programs. The case study illustrates a combined IT and HR driven participative management control system in a flexible organization structure. It is intended for a class discussion rather than to illustrate either effective or ineffective handling of an administrative situation. Case overview The case describes the situation of managing unskilled workforces (≥14,000 workers) during the construction phase of the 4 × 250MW power plants both for purposes of turnout as well as due compensation, in the event of an accident. The approved labour forces appointed for 45 × 8 h. Man-days after a rigorous fitness test and approvals of the safety officer are allocated housing and other necessary amenities and a commensurate compensation system. Expected learning outcomes These include: illustrating typical organizational responsibility structure at a construction site of a large power plant; illustrating the planning and administrative control mechanism in implementing strategy at a construction site of a large power plant; offering students the opportunity to understand and view a typical operational (project) structure; allowing students to speculate adaptations in the wake of an ever-changing business and company environment; and providing an opportunity to introduce a power scenario in India, Indian labour laws and radio frequency identification technology and to relate this to the case in context. Supplementary materials Teaching notes are available; please consult your librarian for access.


Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa

In the Ecuadorian electrical market, several sugar plants, which significantly participate in the local electricity market, are producing their own energy and commercializing the surplus to the electrical market. This study evaluates the integral use of the sugar cane bagasse for productive process on a Cogeneration Power Plant in an Ecuadorian Sugar Company [8]. The electrical generation based on biomass requires a great initial investment. The cost is around US$ 800/kW installed, twice the US$ 400/kW initial investment of conventional thermoelectric power plant and almost equal to the US$ 1,000/kW initial cost of hydroelectric power plant [5]. A thermoeconomic study was carried out on the production of electricity and the sales of the surplus of 27 MWe average produced by the power plant. An operational analysis was made using instantaneous values from the estimated curves of demand and generation of electricity. From the results, it was concluded that the generated electricity costs are 0.0443 US$/kWh, while the costs of the electricity from Fossil Power Plants (burning fuel oil, diesel fuel and natural gas) are in the range 0.03–0.15 US$/kWh and from Hydroelectric Plants are about 0.02 US$/kWh. Cogeneration power plants burning sugar cane bagasse could contribute to the mitigation of climatic change. This specific case study shows the reduction of the prospective emissions of greenhouse gases, around 55,188 ton of CO2 equivalent yearly for this cogeneration power plant.


2020 ◽  
Vol 209 ◽  
pp. 07014
Author(s):  
Tulkin Gayibov ◽  
Bekzod Pulatov

Optimal planning of short-term modes of power systems is a complex nonlinear programming problem with many simple, functional and integral constraints in the form of equalities and inequalities. Especially, the presence of integral constraints causes significant difficulties in solving of such problem. Since, under such constraints, the modes of power system in separate time intervals of the considered planning period become dependent on the values of the parameters in other intervals. Accordingly, it becomes impossible to obtain the optimal mode plan as the results of separate optimization for individual time intervals of the period under consideration. And the simultaneous solution of the problem for all time intervals of the planning period in the conditions of large power systems is associated with additional difficulties in ensuring the reliability of convergence of the iterative computational process. In this regard, the issues of improving the methods and algorithms for optimization of short-term modes of power systems containing thermal and large hydroelectric power plants with reservoirs, in which water consumption is regulated in the short-term planning period, remains as an important task. In this paper, we propose the effective algorithm for solving the problem under consideration, which makes it possible to quickly and reliably determine the optimal operating modes of the power system for the planned period. The results of research of effectiveness of this algorithm are presented on the example of optimal planning of daily mode of the power system, which contains two thermal and three hydraulic power plants..


2014 ◽  
Vol 698 ◽  
pp. 785-789
Author(s):  
Yana Panova ◽  
Vladimir Derbenev ◽  
Anastasiya Zhdanovich

This article is devoted to the principles of constructing the decision support information system at the hydroelectric power plants. It’s assumed that the fuzzy sets theory will be used for the representation of the information about the aggregates operating condition parameters. The paper reflects the advantages of such an approach. The calculations were done for the equipment of the low-head (Novosibirskaya HPP, Hydro Power Plant) and high-head (Sayano–Shushenskaya HPP) power plants. The results obtained are intended for solving the HPPs operational control problems.


2012 ◽  
Vol 12 (10) ◽  
pp. 4429-4447 ◽  
Author(s):  
S. W. Wang ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
R. V. Martin ◽  
...  

Abstract. Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.


Author(s):  
Zhang Ji-Ge ◽  
Zhu Yue

The reactor coolant pump (RCP) is one of the most important components in nuclear power plants. It operated in high temperature, high-pressure, high speed and radiative environment, so a long-term security and reliable operations is required. Many internal flow analysis of RCPs was carried out, mainly foucs on steady and unsteady flow field at different operating points in RCP. The research about flow passage components, such as the blade of the RCP, is relatively few. When the RCPs operates in the nuclear power plant, the flow field lashed against the impeller of the RCP, results in a network of small cracks is found on the surface of impeller. For example, periodic vibration caused by a break in a guide vane leaded to cracking of two pieces blades of impeller in a large power plant in southwest of China, and this accident caused much economic loss. The computational method of stress due to the hydraulic reason is an important problem of the RCP. In this work, at first the CFD simulation including the case, guide vane, impeller, inlet and outlet at different operation points is studied, and the result of the pressure distribution on impeller blade is loaded on the impeller using fluid-structure interation (FSI) method. The result showed that the maximum von Mises stress appears on the trailing edge close to the impeller hub which has a large change in gradient of stress and which is prone to fatigue failure. The maximum stress on the impeller is mainly in proportion to the operating power. The maximum stress on the impeller have periodical characteristic, which is due to the number of blade of diffuser. All of these equip us with better understand of the fatigue and fracture of RCP, and it make sense to protect the fatigue damage and promote the stability of RCP.


2013 ◽  
Vol 437 ◽  
pp. 769-774
Author(s):  
Li Chen ◽  
Nian Su Hu ◽  
Qin Gang Li

As the increment of the power grid scale and the requirement of high power quality, the requirement of the primary frequency regulation (PFR) of large power plant i becomes more and more strictly. In order to improve the PFR performance and to ensure the safety and stability of power plant operation, an experimental analysis was carried out to optimize the control model and parameters of the CCS, DEH and primary frequency.


2013 ◽  
Vol 712-715 ◽  
pp. 2644-2647
Author(s):  
Xiao Ling Luo ◽  
Qi Dui Liang

With the advent of new technologies the development of SIS (supervisory information system) is expanding by leaps and bounds, and SIS function discussion gradually in-depth with a batch of large power plants are put into operation. The establishment of SIS can provide a lot of advantages in terms of control, data viewing and management. Along with the advantages, the correct selection of the proper scheme from wide variety of SIS designs and standards represents an important issue. For the reason the function of the SIS, network architecture and the design are discussed, according to application examples and some related SIS design standards and principles. In addition, the paper puts forwards SIS function development trend and gives a brief description of database according to the cases from power plants. The goal of the paper is to make power system flexible, reliable and minimize management cost. The paper provides some references for research and engineering application of a power plant SIS construction in future.


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