System Of Thermal Power Plant Research Articles

Exergetic analysis and performance evaluation of parabolic trough concentrating solar thermal power plant (PTCSTPP)

Energetic and exergetic analysis has been carried out for the components of the solar thermal power plant system (parabolic trough collector/receiver and Rankine heat engine). The energetic and exergetic losses as well as efficiencies for typical parabolic trough concentrating solar thermal power plant (PTCSTPP) under the specific operating conditions have been evaluated. Operating pressures for a Rankine heat engine have been optimized for maximum efficiency. It has been found that, the energetic and exergetic efficiencies of PTCSTPP increased by 1.49% and 1.51% with increasing pressure from 90 to 105 bar respectively. Progression of the STPP from the variable load to full load conditions, the year round average energetic efficiency can be increased from 22.01% to 22.62% for the location of Jodhpur, and in case of Delhi, it can be increased from 20.98% to 21.50%. Year round average exergetic efficiency can be increased, from 23.66% to 24.32% for the location of Jodhpur and in case of Delhi, it can be increased from 22.56% to 23.11%. Land areas required for the 50 MWe thermal power plants are 79.2 ha and 118.8 ha respectively for the locations of Jodhpur and Delhi.

The Leaching Characteristics of Trace Elements in Coal Fly Ash and an Ash Disposal System of Thermal Power Plants

The present investigation was conducted to study the leaching characteristics of trace elements in coal fly ash and the ash disposal system of thermal power plants. The batch experiment for the fly ash collected from the hopper of the electrostatic precipitator of the thermal power plant, Delhi, was carried out to study the leaching characteristics of Fe, Cr, Cu, Pb, Cd, and Ni. Four leaching time intervals were selected, ranging from 1 week to 4 weeks. From the experiments, leaching behavior of trace elements was investigated and it was observed that ‘Cr’ and ‘Ni’ have a relatively higher leachability in extraction solution than aqueous and buffer solution. Furthermore, with the leaching time, the leachability of ‘Cu’ is increased in aqueous and extraction solution. The leachability of ‘Cd’ increased with leaching time in aqueous and buffer solution. With the increase of leaching time, the leachability of ‘Fe’ in extraction fluid increased with time with small fluctuation.

Design and Experiment Software Platform of Modern Control Algorithm for High-Order Inertial Object

The object of the control system became more and more complicated with the increasing of the capacity of the thermal power plant. One of the key concerns in the area was the high-order and big inertia object, which requested for higher control performance. The experiment and research platform was designed. The real operation data were introduced into the soft platform. Several effective modern control algorithms for the real high-order and big inertia system in thermal power plant were embedded in the design and experiment software platform. For engineer technician and undergraduates, the control system with higher performance for high-order and big inertia object can be researched and designed in the platform easily, which was clearer in physics. Application results show that the practice ability, the innovation ability and the comprehensive quality of the graduates in automation specialty were enhanced greatly and the theoretical level of the engineer technician was increased. By plugging in the computer installation, the soft platform can be used in the real distributed control system (DCS) of the thermal power plant, which has a broad application prospect.

Design and Experiment Software Platform of Modern Control Algorithm for High-Order Inertial Object

The object of the control system became more and more complicated with the increasing of the capacity of the thermal power plant. One of the key concerns in the area was the high-order and big inertia object, which requested for higher control performance. The experiment and research platform was designed. The real operation data were introduced into the soft platform. Several effective modern control algorithms for the real high-order and big inertia system in thermal power plant were embedded in the design and experiment software platform. For engineer technician and undergraduates, the control system with higher performance for high-order and big inertia object can be researched and designed in the platform easily, which was clearer in physics. Application results show that the practice ability, the innovation ability and the comprehensive quality of the graduates in automation specialty were enhanced greatly and the theoretical level of the engineer technician was increased. By plugging in the computer installation, the soft platform can be used in the real distributed control system (DCS) of the thermal power plant, which has a broad application prospect.

Modeling, Control, and Monitoring of $\hbox{S}^{3} \hbox{RS}$-Based Hydrogen Cooling System in Thermal Power Plant

The faster heat dissipation of generators in power plants calls for hydrogen cooling, and water is used as coolant to cool down the hot hydrogen which comes out from the hydrogen cooling system (HCS) at the generating end. Therefore, in large generating plants, the process of cooling and the coolant become integral parts of the heat exchangers. Hence, requirement of a reliable HCS is a must. This paper presents development and implementation of a supervisory-control-and-data-acquisition-based process control and monitoring system. A novel method of six-stage standby redundant structured (S3RS) HCS is proposed for the cooling of large generators in thermal power plant(s). This proposed system is equally reliable for steam-turbine-based generating plants and integrated gasification combined cycle plants. The entire process control and monitoring, popularly known as human-machine interface of HCS, has been developed and simulated on RSViewSE, a real-time automation platform by Rockwell Automation. Additionally, the system reliability of the proposed S3RS process model is implemented using MATLAB. This process model satisfies the specifications of IEEE C37.1-2007, IEEE 1413-2003, IEC 60034-3, IEC 61025, and IEC 61131-3.

Influence of Plant Steam System on Thermal Economy of Thermal Power Plant and Energy Strategy

When the unit is under normal operating, the steam source of plant-steam is from the fourth steam extraction of turbine. But at the low load operating condition, during the process that the steam source of plant steam switches to reheat cold section from the fourth steam extraction, steam power capability in the turbine is further reduced. In this paper, in order to improve the economy when the turbine is operating under the low load, reheat cold section steam is used as high-pressure steam to extract the fourth steam by the steam technology, which turns the low-pressure steam into the medium-pressure steam for recycling. This paper, taking 300MW unit as an example, discusses the influence on the thermal economy of unit after putting the steam ejector into the plant steam system of thermal power plant.

Integrating gray system theory and logistic regression into case-based reasoning for safety assessment of thermal power plants

Safety assessment of thermal power plants (TPPs) is one of the important means to guarantee the safety of production in thermal power production enterprises. Due to various technical limitations, existing assessment approaches, such as analytic hierarchy process (AHP), Monte Carlo methods, artificial neural network (ANN), etc., are unable to meet the requirements of the complex security assessment of TPPs. Currently, most of the security assessments of TPP are completed by the means of experts’ evaluations. Accordingly, the assessment conclusions are greatly affected by the subjectivity of the experts. Essentially, the evaluation of power plant systems relies to a large extent on the knowledge and length of experience of the experts. Therefore in this domain case-based reasoning (CBR) is introduced for the security assessment of TPPs since this methodology models expertise through experience management. Taking the management system of TPPs as breakthrough point, this paper presents a case-based approach for the Safety assessment decision support of TPPs (SATPP). First, this paper reviews commonly used approaches for TPPs security assessment and the current general evaluation process of TPPs security assessment. Then a framework for the Management System Safety Assessment of Thermal Power Plants (MSSATPP) is constructed and an intelligent decision support system for MSSATPP (IDSS-MSSATPP) is functionally designed. IDSS-MSSATPP involves several key technologies and methods such as knowledge representation and case matching. A novel case matching method named Improved Gray CBR (IGCBR) has been developed in which a statistical approach (logistic regression) and Gray System theory are integrated. Instead of applying Gray System theory directly, it has been improved to integrate it better into CBR. In addition this paper describes an experimental prototype system of IDSS-MSSATPP (CBRsys-TPP) in which IGCBR is integrated. The experimental results based on a MSSATPP data set show that CBRsys-TPP has high accuracy and systematically good performance. Further comparative studies with several other common classification approaches also show its competitive power in terms of accuracy and the synergistic effects of the integrated components.

基于太阳能集热技术的火电厂CO2捕捉系统能耗特性分析 Energy Consumption Analysis of Coal-Fired Power Plant with CO2 Capture System Based on Solar Energy

针对火电厂CO2减排的高能耗与高成本问题，本文通过对太阳能集热系统、胺基CO2捕集系统与火电机组热力系统的耦合机理研究及其系统的集成优化，应用等效焓降法，模拟分析了太阳能供能条件下，拥有胺基CO2捕集系统的600 MW燃煤机组在THA、75%THA、50%THA工况下不同碳捕捉率时的热经济性变化情况，得出了不同碳捕捉率下机组运行热经济性的变化趋势，结果表明，机组运行热经济性的相对提高程度随碳捕捉率的增加而增大，在此基础上，进行了系统集成方案的优化设计，以期为实现低能耗、低成本的CO2减排提供借鉴。According to the high energy consumption and cost of CO2 emission reduction in thermal power plant, by the coupling mechanism study and integrated optimization of solar energy collection system, amidogen CO2 emission reduction system and coal-fired power plant thermal system, it is simulated and analyzed that the change of thermal economy of 600 MW Coal-fired units CO2 capture system with amino in the condition of THA、75%THA、50%THA, which has various carbon capture rate, by using equivalent heat drop method, when solar supply energy to the system. And the trend of change on unit operation thermal economy is obtained in different carbon capture rate. It is shown that the relative increase of unit operation thermal economy increases with the carbon capture rate. To the conclusion, Optimization Design of System integrationist is carried out, and reference for achieving low energy consumption and cost of CO2 emission reduction is supplied.

A Novel Method for Analyzing the Thermodynamic System of Thermal Power Plant with Double Reheat Cycles

This paper introduces a novel matrix method for calculating the efficiency of a thermal power plant unit with double reheat cycles. The structure of this matrix method has a mapping relationship with the thermodynamic system of the thermal power plant unit with double reheat cycles, and it can simplify the thermal economic analysis of the double reheat cycles units. An example is given to illustrate the validity of the method.

Intelligent Information Flow Based Real-Time Monitoring System of Thermal Power Plant

Aiming at the existing problems of the monitoring systems of most of the thermal power plants in China, an intelligent information flow based real-time monitoring system of thermal power plant (RT-MSTPP) is proposed. RT-MSTPP is based on the role-based access control (RBAC) model to control different users of business model and the data access, and then realizes the intelligent controlling of the information flow. By using RT-MSTPP, the real-time data of the central equipment in the plant is acquired, their operating state is evaluated and the inchoate fault is predicted. The operating results show that the management of the plant has been improved and the inchoate fault of key equipment can be detected and preliminarily diagnosed.

The Design of Ball Mill Control System Base on Two-Cell Immune Controller

Currently, Ball Mill is most used coal grinding equipment of pulverizing system of thermal power plant in China. Because of this system is multivariable, strong-coupling and serious time-delay, and it also has nonlinear, time-varying and distributed parameter characteristics. It is naturally difficult to be effective for such kind system to use PID regulation law and design multi-variable system by single-loop. So try more intelligent control for this kind system. Immune Control has fast response and robustness, especially; the Two-cell Immune Control has integration and memory characteristics, and improve the system to better control effect. It is particularly suitable for solving practical engineering application problems with robustness, adaptability and requirements of dynamic performance. So this paper use Two-cell Immune Control for the Ball Mill Control System, and make a large number of simulation experiments about rated parameter, non-rated parameter and adding disturbance situation, it has made a good dynamic and static performance under various conditions. These results confirm the validity of the design of Ball Mill Control System base on Two-cell Immune Controller.

Operation and Maintenance of Coal Handling System in Thermal Power Plant

Compared with actual situation of the current thermal power plant, this paper studies operation process of coal handling system in thermal power plant. Analyze technical characteristics of coal handling system and operating characteristics of the relevant machinery and equipment. Then, the safe operation of coal handling system and the proper method of the equipment maintenance are summed up.

Development of carbon dioxide removal system from the flue gas of coal fired power plant

Post-combustion carbon dioxide capture is the technique that can be rapidly and safely employed for substantially reducing carbon dioxide emissions from existing and near future power plants. The key question of the absorption/desorption technique for carbon dioxide removal is process economics. Toshiba is pushing through the post-combustion carbon dioxide capture because it can be employed in rather short period and applied for both retrofit and new power plants. In this work, we evaluated the seven amine-based absorbents as new solvents, which was selected from about 900 amines, in terms of energy consumption for CO2 desorption using a thermodynamic absorption and desorption cycle simulation. We estimated the consumed energy in the stripper when the flue gas contains 12 % CO2 and the capture ratio of CO2 from the flue gas is 90 %. It was found that the lowest energy consumption in the stripper was about 2.5 GJ/t- CO2 when one mixed amine-based aqueous solution (Toshiba Solvent 2, TS-2) was used as the solvent. The value was much lower than that for the general 30 wt.% monoethanolamine (MEA) aqueous solution. And it is lower than our former solvent (Toshiba Solvent 1, TS-1) which was presented at GHGT-9. Then we evaluated the new solvent TS-2 using the bench-scale test facility which contains a complete absorption/desorption process with the absorber and the stripper. At this test TS-2 showed lower consumed energy, less than 2.5 GJ/t- CO2, by optimizing the space velocity of the simulated flue gas and so on, while TS-1 showed about 2.7 GJ/t- CO2 which is nearly equal of the value of the thermodynamic simulation. Parallel to these activities the pilot plant of 10 t- CO2 /day recovery was constructed and commenced in September 2009 with a complete absorption/desorption supplied with the flue gas of a coal fired power plant. In the demonstration tests CO2 capture ratio and captured CO2 rate exceeded the planning values of 90% and 10t- CO2 /day each during continuous 3,000 hour operation. Furthermore the energy consumption for CO2 recovery at the stripper had been kept between 3.2 and 3.3 GJ/t- CO2. These results prove that Toshiba CO2 capture system using TS-1 solvent is a promising system which has been realizing good and stable performances. Toshiba will utilize the results of these studies to further improve and optimize the performance of the system, towards implementation and integration of the system to a larger scale thermal power plant system.

SCADA applications in thermal power plants

This paper presents the applications of a supervisory control and data acquisition (SCADA) system in thermal power plants (TPPs). In fact, a supervisory system must take into account the physiological and cognitive features of the supervisory operator. The paper briefly discusses on the one hand the different steps of the application of a SCADA system and the difficulties to manage and on the other hand it presents three examples of the application of a SCADA system in a TPP in Tunisia and the instrumentations and the measurements used. The first application is related to a counting system of the natural gas, the second one is related to the supervision of pumps vibrations and the third one is related to the supervision of heavy fuel oil. Key words: SCADA, supervision, control, data acquisition, thermal power plant.

An Intelligent Power Plant Fault Diagnostics for Varying Degree of Severity and Loading Conditions

Practical fault diagnosis of a thermal system is very important in ensuring safe and reliable operation of a power plant. However, it is a difficult task due to the structural complexity of a thermal system, varying degree of severity of a fault, and the wide range of operation of the power generating unit. An artificial neural network combined with optimal zoom search is proposed in this paper for recognizing varying degrees of faults in a power plant thermal system operating at different load level. The zoom search technology is based on the similarity rules of the feature variables to a same fault with different severity when the system topological structure does not change with fault or with different loading conditions. Two different types of symptoms, a trend symptom and a semantic symptom, are calculated and jointly used for on-line fault recognition, which results in a faster and more stable fault diagnosis. A feedforward neural network structure is adopted and an improved training method is introduced. A high-pressure feedwater heater system is taken as a target system for investigation. Several simulation tests for diagnosing a multidegree fault under different operating conditions are carried out on a 300-MW power plant simulator to demonstrate the validity of the method.

An Approach to Analyse Energy and Exergy Analysis of Thermal Power Plants: A Review

In this paper, a thermodynamic analysis of a coal based thermal power plant and gas based cogeneration power plant has been carried out. The energy and exergy analysis has been studies for the different components of both power plants. The paper analyses the information available in the open literature regarding energy and exergy analysis on high temperature power plant has been included. A comprehensive literature review on thermal power plants, especially boiler in coal base thermal power plants and combustion chamber in gas-steam cogeneration has been included. Finally, explaining the procedure of analysis of thermal power plant systems by exegetical approach.

Parameter optimization for paraboloid-cylinder-receiver system of thermal power plants

The problems of how to optimize the geometric parameters of the paraboloid-cylinder-receiver (PC-R) system of thermal power plants are examined. The optimal opening angles of the paraboloid-cylindrical concentrator in the system are determined, and it is shown that it is possible to increase the concentration by a factor of two.

Experimental investigation of load behaviour of an industrial scale tumbling mill using noise and vibration signature techniques

Mill load (i.e. the load level of coal powder), which is critical in improving the production capacity and energy efficiency of pulverizing system in thermal power plant, has not been effectively monitored and controlled industrially. This paper investigates the load behaviour in an industrial scale tumbling mill under practical working conditions. A microphone and an accelerometer were installed to pick up mill noise and inlet trunnion vibration signals, respectively. By analyzing the sensitivity distributions of mill noise energy and mill vibration energy, characteristic power spectra (CPS) of mill noise and mill vibration were obtained. The CPS energy, centroid frequency and frequency domain variance of the mill noise and mill vibration were then investigated and compared under various working conditions. Experimental results show that the CPS energy of both mill noise and mill vibration can accurately represent the mill load. Moreover, the centroid frequency and frequency domain variance of mill noise can also be used to determine mill load. By combining these characteristics of mill noise and mill vibration, an improved estimation of mill load can be achieved.

In‐situ catalytic synthesis of ammonia from urea in a semi‐batch reactor for safe utilization in thermal power plant

AbstractUrea as the source of ammonia for the flue gas conditioning/NOx reduction system in thermal power plant has the obvious advantages that no ammonia shipping, handling and storage is required. The process of this invention minimizes the risks and hazards associated with the transport, storage and use of anhydrous and aqueous ammonia, as ammonia is a highly volatile noxious material. But no such rapid urea conversion process is available as per requirement of high conversion in shorter time, so here we study the catalytic hydrolysis of urea for fast conversion in a semi‐batch reactor. The catalysts used in this study are: TiO2, fly ash, mixture of Ni and Fe and Al2O3. Number of experiments was carried out in a semi‐batch reactor at different catalyst doses, temperatures and concentration of urea solution from 10 to 30% by weight and equilibrium study has been made. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Simulation Model for Coal Crushing System of a Typical Thermal Power Plant

The aim of this study is to develop an availability simulation model that can be used for evaluating the performance of coal crushing system of a thermal power plant using probability theory and Markov birth-death process. The present system under study consists of five subsystems with three possible states i.e. full capacity working, reduced capacity working and failed. Failure and repair rates of all subsystems are assumed to be constant. After drawing transition diagram, differential equations have been generated and solved using recursive approach. Then, steady state availability is determined, which is the developed availability simulation model. Besides, some availability matrices are also developed, which provide various performance or availability levels for different combinations of failure and repair rates of all subsystems. Hence, performance of coal crushing system is analyzed and evaluated. The developed model helps the plant management in getting the information about maximum availability of each of the five subsystems with optimum values of failure/repai r rates and in comparative evaluation of alternative maintenance strategies.