Performance Monitoring Systems for Power Plants: General Features and Application Models

Author(s):  
M. Gambini ◽  
M. Vellini

The general features and benefits of a performance monitoring system (PMS) and its capabilities on plant auditing and management are illustrated. The criteria for the validation and reconciliation of the measured data are tackled and the energetic diagnosis of components, by means the comparison between current performance and expected one, is shown. A “on line–real time” monitoring system evaluates the current performance of the power plant immediately and realistically, as well as it informs the operator of problems as soon as they occur and provides diagnostic information so that the operator can remedy the problem. After generals about PMS, two application models are shown: the first one deals with the reconciliation of measured data and it has been numerically developed with reference to a heat recovery steam generator; the second one deals with the energetic diagnosis of plant components and it has been developed with reference to a steam condenser.

Author(s):  
Zhao Chuanli ◽  
Chen Yinqiang ◽  
Xu Feng ◽  
Ji Yuanyuan ◽  
Wang Jiangguo

Fatigue is the major aging mechanism for pipelines and components that are subject to transient during plant operation. In order to avoid abrupt accidents caused by fatigue failure, it is necessary to adopt corresponding techniques to monitor components condition due to fatigue damage. Experience shows that on-line fatigue monitoring system is the most effective way to monitor fatigue damage status of pressure-retaining boundary subjected to operational loads in real-time for NPPs. Several commercial fatigue monitoring systems have been put into application in the nuclear power plants. In this paper, the difference of the international fatigue monitoring systems were compared. As the key technologies of fatigue monitoring system development, the processing of operational load data and the stress influencing function development at monitored locations were researched in the paper. Furthermore, in order to study on the methodologies of the key issues of the system development, the experimental facility was established to improve the knowledge on fatigue monitoring system development for two kinds of input data modules, and the reasonability of the different methods in the study was proved reciprocally. Finally, the on-line fatigue monitoring system for pipelines was established to evaluate actual fatigue damage status.


2021 ◽  
Author(s):  
Vadim Goryachikh ◽  
Fahad Alghamdi ◽  
Abdulrahman Takrouni

Abstract Background information Natural gas liquid (NGL) production facilities, typically, utilize turbo-expander-brake compressor (TE) to generate cold for C2+ separation from the natural gas by isentropic expansion of feed stream and use energy absorbed by expansion to compress residue gas. Experience shows that during operational phase TE can exposed to operation outside of design window that may lead to machine integrity loss and consequent impact on production. At the same time, there is a lack of performance indicators that help operator to monitor operating window of the machine and proactively identify performance deterioration. For instance, TE brake compressor side is always equipped with anti-surge protection system, including surge deviation alarms and trip. However, there is often gap in monitoring deviation from stonewall region. At the same time, in some of the designs (2×50% machines) likelihood of running brake compressor in stonewall is high during one machine trip or train start-up, turndown operating modes. Also, typical compressor performance monitoring systems does not have enough dynamic parameters that may indicate machine process process performance deterioration proactively (real-time calculation of actual polytrophic efficiency, absorbed power etc.) and help operator to take action before catastrophic failure occurs. In addition, typical compressor monitoring systems are based on assumed composition and fixed compressibility factor and do not reflect actual compositions variations that may affect machine performance monitoring. To overcome issues highlighted above, Hawiyah NGL (HNGL) team has developed computerized monitoring and advisory system to monitor the performance of turbo-expander-brake compressor, proactively, identify potentially unsafe conditions or performance deterioration and advice operators on taking necessary actions to avoid unscheduled deferment of production. Computerized performance monitoring system has been implemented in HNGL DCS (Yokogawa) and utilized by control room operators on day-to-day basis. Real-time calculation, analysis and outputs produced by performance monitoring system allow operator to understand how current operating condition are far from danger zone. Proactive deviation alarms and guide messages produce by the system in case of deviation help operators to control machine from entering unsafe region. Actual polytrophic efficiency, adsorbed power calculations provide machine condition status and allow identifying long-term performance deterioration trends.


Author(s):  
Akber Pasha

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.


Author(s):  
Helmer Andersen

Fuel is by far the largest expenditure for energy production for most power plants. New tools for on-line performance monitoring have been developed for reducing fuel consumption while at the same time optimizing operational performance. This paper highlights a case study where an online performance-monitoring tool was employed to continually evaluate plant performance at the Kalaeloa Combined Cycle Power Plant. Justification for investment in performance monitoring tools is presented. Additionally the influence of various loss parameters on the cycle performance is analyzed with examples. Thus, demonstrating the potential savings achieved by identifying and correcting the losses typically occurring from deficiencies in high impact component performance.


Author(s):  
H. H. Finckh ◽  
H. Pfost

Unfired combined cycles achieve superior efficiencies at low emission levels. The potential and efficiency limits are investigated and the possibilities for enhancing efficiency are described. It is demonstrated that limited supplementary firing of the heat recovery steam generator can be an interesting alternative and that this allows efficiency and plant size to be increased. The effects of supplementary firing on NOx emissions are also shown.


2013 ◽  
Vol 303-306 ◽  
pp. 431-434 ◽  
Author(s):  
Xin Jing Zou ◽  
Li Bian ◽  
Yong Hui Zhai

This paper describes the design of an on-line monitoring system for grid-connected photovoltaic plants. The proposed system consists of a meteorological data collection system for measuring meteorological parameters (e.g. irradiance, ambient air temperature, etc.), a set of data collection boxes for measuring electrical parameters (e.g. DC and AC current, DC and AC voltage, DC and AC power, etc.) and a PC. The collected data have been transmitted to the PC by two methods, wired transmission and wireless transmission. The software of the on-line monitoring system based on LabVIEW (Laboratory Virtual Instrument Engineering Workbench) package is used to process, display and store the collected data in the PC disk. The on-line monitoring system was installed in a grid-connected photovoltaic plant for an on-site measurement in Qinghai province in China. The obtained results demonstrate that it has the ability for data collecting, processing and analyzing and it meets the measurement requirements of grid-connected PV plants


Author(s):  
P. J. Dechamps

Natural gas fired combined cycle power plants now take a substantial share of the power generation market, mainly because they can be delivering power with a remarkable efficiency shortly after the decision to install is taken, and because they are a relatively low capital cost option. The power generation markets becoming more and more competitive in terms of the cost of electricity, the trend is to go for high performance equipments, notably as far as the gas turbine and the heat recovery steam generator are concerned. The heat recovery steam generator is the essential link in the combined cycle plant, and should be optimized with respect to the cost of electricity. This asks for a techno-economic optimization with an objective function which comprises both the plant efficiency and the initial investment. This paper applies on an example the incremental cost method, which allows to optimize parameters like the pinch points and the superheat temperatures. The influence of the plant load duty on this optimization is emphasized. This is essential, because the load factor will not usually remain constant during the plant life-time. The example which is presented shows the influence of the load factor, which is important, as the plant goes down in merit order with time, following the introduction of more modern, more efficient power plants on the same grid.


1997 ◽  
Vol 119 (4) ◽  
pp. 250-256 ◽  
Author(s):  
H. Jin ◽  
M. Ishida ◽  
M. Kobayashi ◽  
M. Nunokawa

Two operating advanced power plants, a supercritical steam plant and a gas-steam turbine combined cycle, have been analyzed using a methodology of graphical exergy analysis (EUDs). The comparison of two plants, which may provide the detailed information on internal phenomena, points out several inefficient segments in the combined cycle plant: higher exergy loss caused by mixing in the combustor, higher exergy waste from the heat recovery steam generator, and higher exergy loss by inefficiency in the power section, especially in the steam turbine. On the basis of these fundamental features of each plant, we recommend several schemes for improving the thermal efficiency of current advanced power plants.


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