scholarly journals Maintenance Strategy Optimization of a Coal-Fired Power Plant Cooling Tower through Generalized Stochastic Petri Nets

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1951 ◽  
Author(s):  
Arthur H.A. Melani ◽  
Carlos A. Murad ◽  
Adherbal Caminada Netto ◽  
Gilberto F.M. Souza ◽  
Silvio I. Nabeta

Determining the ideal size of maintenance staff is a daunting task, especially in the operation of large and complex mechanical systems such as thermal power plants. On the one hand, a significant investment in maintenance is necessary to maintain the availability of the system. On the other hand, it can significantly affect the profit of the plant. Several mathematical modeling techniques have been used in many different ways to predict and improve the availability and reliability of such systems. This work uses a modeling tool called generalized stochastic Petri net (GSPN) in a new way, aiming to determine the effect that the number of maintenance teams has on the availability and performance of a coal-fired power plant cooling tower. The results obtained through the model are confronted with a thermodynamic analysis of the cooling tower that shows the influence of this system’s performance on the efficiency of the power plant. Thus, it is possible to determine the optimal size of the repair team in order to maximize the plant’s performance with the least possible investment in maintenance personnel.

Author(s):  
Muhammad A. Raza ◽  
Krishan L. Khatri ◽  
Sunila Akbar ◽  
Muhammad I. U. Haque

In this paper, performance evaluation and technical audit of a 747 MW thermal power plant consisting of three generating units is conducted. The factors influencing the performance of the plant have been identified and improvements in processes and mechanical, electrical, instrumentation, and safety engineering are suggested. These improvements would result in better profitability, productivity, and performance. The paper further discusses technical issues and challenges and identifies key areas where improvements are possible. Future recommendation for the operation of the plant that would result in better throughput are also presented. The methodology of performance analysis presented in the paper will help improving operational efficiency of thermal power plants in developing countries.


2011 ◽  
Vol 133 (04) ◽  
pp. 42-43 ◽  
Author(s):  
Louis Michaud ◽  
Nilton Renno

This article discusses building a prototype of an atmospheric vortex engine (AVE) to increase the thermodynamic efficiency of a thermal plant. An AVE would look like a natural draft cooling tower with a controlled vortex emerging from its open top. An AVE tower could have a diameter of 300 feet and stand 10 to 20 stories tall. To fully demonstrate the AVE concept, however, it is likely necessary to build and test a prototype at an existing thermal power plant. Building the prototypes at existing thermal power plants would be advantageous because of the availability of a controlled heat source of relatively high temperature. Possessing some 20% or 30% of the capacity of the existing cooling tower, the prototype would be able to accept a fraction of the waste heat from the plant. A small gas-fired power plant in a rural location with a dry cooling tower would be a good candidate site for an AVE prototype, since it could be developed without risk to existing plant operation.


Author(s):  
Stefan aus der Wiesche

Abstract Flexible plant operation and rapid load changes become major issues for steam turbine operation. In thermal power plants, the steam turbine performance is closely related to the condenser, and an accurate prediction of coolant temperature as function of changing weather conditions is necessary in order to optimize power plant fleet operation. In this contribution, a one-dimensional model for simulating the performance of large natural draft wet cooling towers is presented. The evaporation zone model rests on the evaporative cooling theory developed by Merkel and Poppe. The off-design behavior of the cooling tower, that is relevant to part load performance, is modeled by an empirical power-law approach. A user-friendly method is presented in order to identify required model parameters by means of already available power plant data. The simulation tool can be employed easily for existing power plants for which the original cooling tower design and construction data lost their validity. The outcome of the present calculation method is successfully compared with field data from representative cooling towers at Middle-European sites.


2012 ◽  
Vol 58 (4) ◽  
pp. 351-356
Author(s):  
Mincho B. Hadjiski ◽  
Lyubka A. Doukovska ◽  
Stefan L. Kojnov

Abstract Present paper considers nonlinear trend analysis for diagnostics and predictive maintenance. The subject is a device from Maritsa East 2 thermal power plant a mill fan. The choice of the given power plant is not occasional. This is the largest thermal power plant on the Balkan Peninsula. Mill fans are main part of the fuel preparation in the coal fired power plants. The possibility to predict eventual damages or wear out without switching off the device is significant for providing faultless and reliable work avoiding the losses caused by planned maintenance. This paper addresses the needs of the Maritsa East 2 Complex aiming to improve the ecological parameters of the electro energy production process.


Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.


2021 ◽  
Vol 11 (11) ◽  
pp. 4974
Author(s):  
Tran X. Phuoc ◽  
Mehrdad Massoudi

To our knowledge, the potential use of CO2 as a heat-transmitting fluid for cooling applications in power plants has not been explored very extensively. In this paper, we conduct a theoretical analysis to explore the use of CO2 as the heat transmission fluid. We evaluate and compare the thermophysical properties of both dry air and CO2 and perform a simple analysis on a steam-condensing device where steam flows through one of the flow paths and the cooling fluid (CO2 or air) is expanded from a high-pressure container and flows through the other. Sample calculations are carried out for a saturated-vapor steam at 0.008 MPa and 41.5 °C with the mass flow rate of 0.01 kg/s. The pressure of the storage container ranges from 1 to 5 MPa, and its temperature is kept at 35 °C. The pressure of the cooling fluid (CO2 or dry air) is set at 0.1 MPa. With air as the heat-removing fluid, the steam exits the condensing device as a vapor-liquid steam of 53% to 10% vapor for the container pressure of 1 to 5 MPa. With CO2 as the heat-removing fluid, the steam exits the device still containing 44% and 7% vapor for the container pressure of 1 MPa and 2 MPa, respectively. For the container pressure of 3 MPa and higher, the steam exits the device as a single-phase saturated liquid. Thus, due to its excellent Joule–Thomson cooling effect and heat capacity, CO2 is a better fluid for power plant cooling applications. The condensing surface area is also estimated, and the results show that when CO2 is used, the condensing surface is 50% to 60% less than that when dry air is used. This leads to significant reductions in the condenser size and the capital costs. A rough estimate of the amount of CO2 that can be stored and utilized is also carried out for a steam power plant which operates with steam with a temperature of 540 °C (813 K) and a pressure of 10 MPa at the turbine inlet and saturated-vapor steam at 0.008 MPa at the turbine outlet. The results indicate that if CO2 is used as a cooling fluid, CO2 emitted from a 1000 MW power plant during a period of 250 days could be stored and utilized.


2011 ◽  
Vol 383-390 ◽  
pp. 4130-4133
Author(s):  
Song Feng Tian ◽  
Wei Wang ◽  
Yun Feng Tian ◽  
Shuang Bai Liu

There are many kinds of energy loss indicators in power plant, and there are some relevance among the various indicators. So extraction of the key indicators plays an important role between in energy loss analysis of power plants and optimal management of thermal power plants. Based on the characteristics of these indicators, the idea of rough sets was applied to the energy loss analysis of thermal power plants, then we proposed a new algorithm -- use fuzzy C means algorithm (FCM) to discrete cluster the energy loss indicators of thermal power plant, and then analysis simplified the results with algorithm Johnson. Real experiments (Chaozhou 1,2 and Ningde 3,4 assembling units which of the same type in the SIS system under the THA working condition)’ results had proved high accuracy and valuable of the algorithm.


Author(s):  
Kajori Parial ◽  
S. Mukherjee ◽  
A. R. Ghosh ◽  
D. Sengupta

Coal combustion in thermal power plants releases ash. Ash is reported to cause different adverse health hazards in humans and other organisms. Owing to the presence of radionuclides, it is also considered as a potential radiation hazard. In this study, based on the surface radiation measurements and relevant ancillary data, expected radiation risk zones were identified with regard to the human population residing near the Thermal Power Plant. With population density as the risk determining criteria, about 20% of the study area was at &lsquo;High&rsquo; risk and another 20% of the study area was at &lsquo;Low&rsquo; risk zone. The remaining 60% was under medium risk zone. Based on the findings remedial measures which may be adopted have been suggested.


Sign in / Sign up

Export Citation Format

Share Document