scholarly journals Study of the impact of NPP rated thermal power uprate on process behavior at different transient conditions

2018 ◽  
pp. 9-13 ◽  
Author(s):  
A. G. Nikulenkov ◽  
D. V. Samoilenko ◽  
T. V. Nikulenkova
Keyword(s):  
Power Unit ◽  
Thermal Power ◽  
Operating Conditions ◽  
Life Assessment ◽  
Feed Water ◽  
Dimensional System ◽  
Residual Service Life ◽  
Safety Level ◽  
Coolant Pump ◽  
The Impact

Today, objective preconditions have been formed to find the ways on how to increase cost-effectiveness of NPPs operation, while providing the required safety level. One of such ways to increase thermal nominal power of power unit. The paper provides for the results of reactor behavior analysis at increased thermal power above nominal received using a one-dimensional system computer code RELAP5/MOD3.2 and relevant model of VVER-1000 (V-320) power unit. Calculation analyses are performed for quasi-static reactor operating conditions and transients using realistic approach in terms of initial performance parameters of reactor installation. In researches, representative initial events for transients have been selected according to the principle described further. For an abnormal operation, an event has been selected based on its high frequency and consequences, which require decreasing reactor power down to 50 % of nominal thermal power. For emergency conditions an event has been selected which is caused by external extreme impacts typical for Ukrainian NPP sites resulting in the worst consequences. Thus, the transients are represented by events associated with failure of a single turbine-driven feed water pump and total station blackout unit. To analyze emergency conditions caused by long-term blackout, they were additionally accompanied by a leakage through reactor coolant pump seals. Given that increase of steam flow in a turbine at increased thermal power above nominal requires additional studies on residual service life assessment of its critical components, a 3-D model of high-pressure rotor of a full speed turbine is proposed for further studies. Based on the calculations a comparative analysis of major parameters of the reactor at rated and increased thermal power is performed with assessment of significant factors to be considered in further studies on increase of installed thermal output of NPP unit.

Springs® Design Optimized By Seawater Quality. Laboratory Pilot Tests

2021 ◽  
Author(s):  
Pierre Pedenaud ◽  
Marianna Rondon ◽  
Nicolas Lesage ◽  
Eric Tournis ◽  
Riccardo Giolo ◽  
...  
Keyword(s):  
Water Quality ◽  
Operating Conditions ◽  
Single Stage ◽  
Plant Performance ◽  
Future Application ◽  
Feed Water ◽  
Nanofiltration Membranes ◽  
Two Stage ◽  
Seawater Quality ◽  
The Impact

Abstract A new seawater laboratory pilot has been installed in order to evaluate the impact of the seawater quality on the performance of nanofiltration membranes and filters. The test program implemented was designed to produce the data required to optimize the design and operating parameters of a subsea sulfate removal plant, particularly with respect to the technology developed by Total, Saipem and Veolia, co-owners of the development. The equipment qualification plan is approaching completion with the development of subsea barrier-fluidless pumps, all-electric control systems, high-cycling valves operated by electric actuators and subsea water analyzers. This presented pilot laboratory study completes this plan. Nanofiltration membranes are commonly used to remove the sulfates found in seawater before the water is injected into wells. The principal advantages of relocating this equipment from topside to subsea are better reservoir sweep control, a substantial subsea water injection network reduction and savings on space and weight on the topsides deck. The move to subsea offers the opportunity to simplify the process due to improved deep water quality. This was previously demonstrated through a subsea test campaign. This new pilot study provides data both on the performance of a plant operating with different feed water quality and on the success of operating changes to further optimize the plant performance. The pilot has been installed at the Palavas-les-Flots site in France. Raw water collected from the basin was mixed with ultra-filtered water in order to calibrate the feed water quality. The pilot includes a two stage nanofiltration configuration and single stage nanofiltration unit. The two stage configuration was used to produce data for operation across an array of feed water quality and plant operating conditions. The single stage unit was used to produce data on membrane fouling over a long operating duration. Results from these tests and discussion on how this data relates to subsea plant performance shall be presented. This innovative approach enables a wide range of subsea water quality to be simulated and tested against different process configurations of the subsea unit. Indeed, for each industrial subsea application, the raw seawater quality is dependent on both the region and the depth of the seawater inlet. With this experimental data acquisition campaign and understanding of the seawater quality at inlet, the system design can be tailor-made for each future application case.

Arsenic mass balance in a paper mill and impact of the arsenic release from the WWTP effluent on the Moselle River

2011 ◽  
Vol 63 (7) ◽  
pp. 1349-1356 ◽  
Author(s):  
C. Michon ◽  
M.-N. Pons ◽  
P. Bauda ◽  
H. Poirot ◽  
O. Potier
Keyword(s):  
Arsenic Concentration ◽  
Treatment Plant ◽  
Paper Mill ◽  
Operating Conditions ◽  
Anthropogenic Source ◽  
Feed Water ◽  
Water Production ◽  
Gravel Pit ◽  
Wwtp Effluent ◽  
The Impact

Rivers used for drinking water production might be subject to anthropogenic pollution discharge upstream of the intake point. This problem was investigated in the case of the Moselle River, used for water production in Nancy (350,000 inhabitants) and which might be impacted by industrial activities 60 km upstream. The arsenic flux of a pulp and paper mill discharging in the Moselle River at this location has been more specifically investigated. The main sources of arsenic in that mill seemed to be the recovered papers and the gravel pit water used as feed water. The arsenic input related to wood and bark was limited. The main arsenic outputs from the plant were the paper produced on site and the deinking sludge. The arsenic concentration in the effluent of the wastewater treatment plant (WWTP) was not correlated to the one in the gravel pit water, but may depend on the operating conditions of the WWTP or the changes in processes of the mill. The impact of this anthropogenic source of arsenic on the Moselle River was slightly larger in summer, when the flowrate was lower. Globally the impact of the paper mill on the Moselle River water quality was limited in terms of arsenic.

scholarly journals Multi-Time Scale Rolling Economic Dispatch for Wind/Storage Power System Based on Forecast Error Feature Extraction

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2124 ◽  
Author(s):  
Li Han ◽  
Rongchang Zhang ◽  
Xuesong Wang ◽  
Yu Dong
Keyword(s):  
Power System ◽  
Real Time ◽  
Wind Power ◽  
Power Unit ◽  
Time Scale ◽  
Forecast Error ◽  
Thermal Power ◽  
Time Error ◽  
The Real ◽  
The Impact

This paper looks at the ability to cope with the uncertainty of wind power and reduce the impact of wind power forecast error (WPFE) on the operation and dispatch of power system. Therefore, several factors which are related to WPFE will be studied. By statistical analysis of the historical data, an indicator of real-time error based on these factors is obtained to estimate WPFE. Based on the real-time estimation of WPFE, a multi-time scale rolling dispatch model for wind/storage power system is established. In the real-time error compensation section of this model, the previous dispatch plan of thermal power unit is revised according to the estimation of WPFE. As the regulating capacity of thermal power unit within a short time period is limited, the estimation of WPFE is further compensated by using battery energy storage system. This can not only decrease the risk caused by the wind power uncertainty and lessen wind spillage, but also reduce the total cost. Thereby providing a new method to describe and model wind power uncertainty, and providing economic, safe and energy-saving dispatch plan for power system. The analysis in case study verifies the effectiveness of the proposed model.

Pump Bearing Fault Detection Based on EMD and SVM

2018 ◽  
Author(s):  
Yi Feng ◽  
Xianling Li ◽  
Zhiwu Ke ◽  
Zhaoxu Chen ◽  
Mo Tao
Keyword(s):  
Heat Transfer ◽  
Correlation Coefficient ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Support Vector ◽  
Stable Operation ◽  
Feed Water ◽  
Intrinsic Mode Functions ◽  
Coolant Pump ◽  
Term Operation

In nuclear power plant system, pump is the key equipment to maintain the flow of the primary loop coolant and the secondary loop heat transfer fluid. The main coolant pump and the feed water pump are in long-term operation status. Bearings are the key components to ensure stable operation of the pump, and which could be damaged in abnormal conditions. Once the failure occurred in the bearings, pumps would exhibit periodic vibration, which might cause the flow pulsations of coolant and heat transfer fluid; gradually, these situations could reduce the control accuracy and the stability of pump. Therefore, the detection and diagnosis of pump bearings are significant to improve the safety and stability of reactor system. We proposed an approach combined with signal processing and machine learning to extract the signal features and recognize the signal samples automatically. The proposed approach consists of three main steps: firstly, empirical mode decomposition (EMD) is applied to decompose the signals into several intrinsic mode functions (IMFs) which are corresponding to the different components of the original signals; secondly, calculating the correlation coefficient between each IMF and the original signal, the correlation coefficient sequence imply the components distribution of the signal which can be applied to recognize the signal samples; finally, extracting a part of correlation coefficient sequences to train the support vector machine (SVM), and then an classifier can be obtained and use to recognize the other signal samples automatically. Experimental results show that this method can effectively detect the pump bearing operating conditions and failures, and can provide a reference for the safe and stable operation of reactor pumps.

scholarly journals Integration of Process Modeling, Design, and Optimization with an Experimental Study of a Solar-Driven Humidification and Dehumidification Desalination System

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 163 ◽  
Author(s):  
Mohammed Alghamdi ◽  
Faissal Abdel-Hady ◽  
A. Mazher ◽  
Abdulrahim Alzahrani
Keyword(s):  
Closed Loop ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Circulation Rate ◽  
Feed Water ◽  
Parabolic Trough ◽  
Circulating Water ◽  
Electrical Generation ◽  
The Impact ◽  
Promising Source

Solar energy is becoming a promising source of heat and power for electrical generation and desalination plants. In this work, an integrated study of modeling, optimization, and experimental work is undertaken for a parabolic trough concentrator combined with a humidification and dehumidification desalination unit. The objective is to study the design performance and economic feasibility of a solar-driven desalination system. The design involves the circulation of a closed loop of synthetic blend motor oil in the concentrators and the desalination unit heat input section. The air circulation in the humidification and dehumidification unit operates in a closed loop, where the circulating water runs during the daytime and requires only makeup feed water to maintain the humidifier water level. Energy losses are reduced by minimizing the waste of treated streams. The process is environmentally friendly, since no significant chemical treatment is required. Design, construction, and operation are performed, and the system is analyzed at different circulating oil and air flow rates to obtain the optimum operating conditions. A case study in Saudi Arabia is carried out. The study reveals unit capability of producing 24.31 kg/day at a circulating air rate of 0.0631 kg/s and oil circulation rate of 0.0983 kg/s. The tradeoff between productivity, gain output ratio, and production cost revealed a unit cost of 12.54 US$/m3. The impact of the circulating water temperature has been tracked and shown to positively influence the process productivity. At a high productivity rate, the humidifier efficiency was found to be 69.1%, and the thermal efficiency was determined to be 82.94%. The efficiency of the parabolic trough collectors improved with the closed loop oil circulation, and the highest performance was achieved from noon until 14:00 p.m.

Application of Surrogate Models and Probabilistic Design Methodology to Assess Creep Growth Limit of an Uncooled Turbine Blade

2018 ◽  
Author(s):  
Armin Hadadian ◽  
Sairam Prabhakar ◽  
Bjorn Sjodin ◽  
Keith Taylor
Keyword(s):  
Turbine Blade ◽  
Model Development ◽  
Engine Performance ◽  
Operating Conditions ◽  
Life Assessment ◽  
Creep Life ◽  
Validation Data ◽  
Data Set ◽  
Creep Life Assessment ◽  
The Impact

Predictive lifing with probabilistic treatment of key variables represents a promising approach to realizing the digital gas turbine of the future. In this paper, we present a predictive model for creep life assessment of an uncooled turbine blade. The model development methodology draws on well-established machine learning principles to develop and validate a surrogate model for creep life from engine performance parameters. Verified creep life results, obtained from 3D non-linear thermo-mechanical finite element simulation for varying engine operating conditions are used as the basis for model development. The selection of model response surface order is studied over a range of models by evaluating normalized residual error on training and uncorrelated validation data sets. A model that is fully quadratic in the data set features is shown to have excellent predictive capability, yielding nominal creep life predictions to within ± 3% on the validation data set. This work then considers probabilistic techniques to evaluate the impact of uncertainty associated with each key factor on the predicted nominal creep life in order to achieve a mandated life target with a defined probability of failure.

Towards an Acceptable Pipeline Integrity Target Reliability

2016 ◽  
Author(s):  
Sherif Hassanien ◽  
Len Leblanc ◽  
Alex Nemeth
Keyword(s):  
Unit Length ◽  
Probability Of Failure ◽  
Operating Conditions ◽  
Probabilistic Methods ◽  
Pipeline System ◽  
Reliability Engineering ◽  
Safety Level ◽  
Main Challenge ◽  
Pipeline Segment ◽  
The Impact

Integrity reliability analysis is becoming an important component of effective pipeline integrity management systems. It aims at utilizing reliability engineering to address integrity uncertainties and check pipeline reliability measures against safety objectives/targets. In current practice, pipeline safety is typically verified using simplified deterministic procedures based on a safety factor approach that is tailored to the design of new pipes. A more realistic verification of actual safety performance of existing pipelines can be achieved by probabilistic methods where uncertainties of basic random variables are considered and the impact on the reliability of the system is analyzed. To enable such an approach, specification of integrity target reliability levels is required in order to benchmark the safety level of an existing pipeline system. The probability of failure (PoF) per pipeline segment or unit length is quantified and then checked against an integrity permissible probability of failure (PoFp) or integrity target reliability (1-PoFp). This check against a specified reliability target allows the operator to confidently determine whether a segment of pipe is safe at current operating conditions while considering identified uncertainties. However, the main challenge around reliability targets is choosing such targets to begin with. This paper presents a semi-quantitative validation approach for estimating integrity reliability targets based on calibrating past failure incidents and evaluating PoF at the time of failure. Accounting for both aleatory and epistemic uncertainties in assigning the integrity targets, pipeline operators can gauge how to choose such targets and how to be flexible in terms of customizing integrity targets based on their asset performance and adopted integrity programs. A brief summary of published reliability targets in pipeline and non-pipeline industries is presented herein.

Understanding how operating conditions affect biofouling structure in spacer filled membrane filtration channels using optical coherence tomography

2020 ◽  
Author(s):  
Kees Theo Huisman ◽  
Bastiaan Blankert ◽  
Szilard Bucs ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Optical Coherence Tomography ◽  
Reverse Osmosis ◽  
System Performance ◽  
Operating Conditions ◽  
Process Conditions ◽  
Feed Water ◽  
Optical Coherence ◽  
Biofilm Development ◽  
Biofilm Structure ◽  
The Impact

<p><strong>Abstract</strong></p> <p>The growth of biofilms, causing biofouling on the membrane and feed spacer surface, is an unavoidable phenomenon in reverse osmosis. Biofouling can lead to unacceptable losses in product quality and quantity, and membrane lifetime. Process conditions such as crossflow velocity and nutrient concentration in the feed water strongly affect the development of biofilms. To improve system performance, understanding the relation between process conditions, biofilm development, and system performance is key. Optical coherence tomography (OCT), is increasingly applied to characterize biofilm structure in-situ and non-destructively. In OCT, near-infrared light is used to capture 2D and 3D images from within optical scattering media. In spacer filled channels with representative biodegradable nutrient conditions in the feed, biofilms often develop heterogeneously and dispersed. In such systems, commonly used structural parameters such as average thickness, average roughness, and average porosity may not be reflected in the system performance.</p> <p>In this study, biofilm structural and spatial parameters are explored with the objective to link biofouling in spacer filled channels to system performance indicators. For this purpose, biofilms are grown in membrane fouling simulators at different nutrient concentrations and flow rates. Biofilm development on the feed spacer and on the membrane and system performance (pressure drop, transmembrane pressure, rejection) are monitored. Understanding the impact of (i) feed water quality and flow rate on biofilm growth and of (ii) biofilm structure and spatial distribution on system performance will lead to the development of more effective strategies for biofouling control.</p> <p><strong>Keywords</strong></p> <p>Biofouling; desalination; drinking water production; reverse osmosis; optical coherence tomography; feed spacer; biofilm structure</p>

scholarly journals Improving the reliability of the energy supply to the district boiler house

2021 ◽  
Vol 2094 (5) ◽  
pp. 052033
Author(s):  
D S Balzamov ◽  
V V Bronskaya ◽  
A A Lubnina ◽  
Ch B Minnegalieva ◽  
L E Khairullina ◽  
...  
Keyword(s):  
Energy Supply ◽  
Thermal Power ◽  
Boiler House ◽  
Operating Conditions ◽  
Electrical Network ◽  
Automation System ◽  
Gas Engine ◽  
Energy Supply System ◽  
Technical Specifications ◽  
The Impact

Abstract Currently, measures are being worked out at generation facilities, in particular at district boiler houses, the implementation of which will increase the reliability of both individual elements of the system and the entire energy supply system as a whole, improve its technical and economic indicators, and achieve the target financial indices of the enterprise. As one of such measures, the article considers the ways of organizing a mini-TPP (thermal power plant) on the example of a large district boiler house for the purpose of energy supply for their own needs. This solution will increase the energy independence of the boiler house from the external network, reduce the cost of electricity consumption. The paper presents the results of a technical and economic analysis of options for organizing own generation, taking into account the actual operating conditions of the boiler house, linking the mini-TPP to the existing communications of boiler house, the impact of the joint operation of the mini-TPP and the boiler house on the sanitary zone. Based on the analysis of the loading graphs of the electric equipment of the boiler house, the required capacity of the gas engine generator plant and the place of its installation on the production site are determined. The operation of the gas engine generator plant involves the production of electric energy only for its own needs without issuing it to an external electrical network, in connection with which an automation system is provided that does not allow electricity to be issued to an external network. This restriction is related to the requirements of the technical specifications of the electric grid company.

scholarly journals The processes of vaporization in the porous structures working with the excess of liquid

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 363-373 ◽  
Author(s):  
Alexander Genbach ◽  
Nellya Jamankulova ◽  
Vukman Bakic
Keyword(s):  
Temperature Difference ◽  
High Speed ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Power ◽  
Laser System ◽  
Operating Conditions ◽  
Design Parameters ◽  
Porous Structures ◽  
The Impact

The processes of vaporization in porous structures, working with the excess of liquid are investigated. With regard to the thermal power plants new porous cooling system is proposed and investigated, in which the supply of coolant is conducted by the combined action of gravity and capillary forces. The cooling surface is made of stainless steel, brass, copper, bronze, nickel, alundum and glass, with wall thickness of (0.05-2)?10-3 m. Visualizations of the processes of vaporization were carried out using holographic interferometry with the laser system and high speed camera. The operating conditions of the experiments were: water pressures (0.01-10) MPa, the temperature difference of sub-cooling (0-20)?C, an excess of liquid (1-14) of the steam flow, the heat load (1-60)?104 W/m2, the temperature difference (1-60)?C and orientation of the system (? 0 - ? 90) degrees. Studies have revealed three areas of liquid vaporization process (transitional, developed and crisis). The impact of operating and design parameters on the integrated and thermal hydraulic characteristics was defined. The optimum (minimum) flow rate of cooling fluid and the most effective type of mesh porous structure were also defined.

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