Anomaly detection for heavy power generation gas turbine considering the effect of output power variation

Author(s):  
Zhong Wang ◽  
Yujiong Gu ◽  
Xudong Han ◽  
Junjie Zhu ◽  
Jiaohui Xu

In the frequency modulation process of the heavy power generation gas turbine, the variation of output power will cause the fluctuation of the operating parameters. In order to detect the anomaly of the true performance deterioration accurately, a novel statistical anomaly detection model was developed. First, the mathematical description of the operating parameters under three different operating conditions—unsteady-state, steady-state and normal, steady-state and anomaly—was presented according to the characteristics of parameters and output power. Second, the new characteristic test statistic P-ratio based on the T-statistic was proposed for the anomaly detection under the steady-state condition. Then, the on-line steady-state detection algorithm based on the Gaussian mixture model was built for the unsteady-state identification. Finally, the efficacy of the model was examined on the synthetic deterioration data, which superimposes the anomaly simulation signal data on the real healthy data from a real power generation gas turbine. The testing result is shown to be satisfactory with respect to the false positive rate and the true positive rate. Future research is required to further improve the accuracy of the proposed model.

Author(s):  
R. Bettocchi ◽  
P. R. Spina ◽  
F. Fabbri

In the paper the dynamic non-linear model of single shaft industrial gas turbine was developed as the first stage of a methodology aimed at the diagnosis of measurement and control sensors and gas turbine operating conditions. The model was calibrated by means of reference steady-state condition data of a real industrial gas turbine and was used to simulate various machine transients. The model is modular in structure and was carried out in simplified form, but not so as to compromise its accuracy, to reduce the calculation time and thus make it more suitable for on-line simulation. The comparison between values of working parameters obtained by the simulations and measurements during some transients on the gas turbine in operation provided encouraging results.


2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879407 ◽  
Author(s):  
Wei Liu ◽  
Xiaoyun Zhang ◽  
Ningbo Zhao ◽  
Chunying Shu ◽  
Shanke Zhang ◽  
...  

Intercooled cycle gas turbine has great potential in improving the output power because of the low energy consumption of high-pressure compressor. In order to more efficiently recovery and utilize the waste heat of the intercooled system, an organic Rankine cycle power generation system is developed to replace the traditional intercooled system in this study. Considering the effects of different kinds of organic working fluids, the thermodynamic performance of organic Rankine cycle power generation system is investigated in detail. On this basis, the sensitivity analyses of some key parameters are conducted to study the operating improvements of organic Rankine cycle power generation system. The results indicate that the integration of organic Rankine cycle and intercooled cycle gas turbine not only can be used for waste heat power generation but also increases the output power and efficiency of intercooled cycle gas turbine by selecting the organic working fluids of n-butane (R600), n-pentane (R601), toluene, and n-heptane. And compared to the others, organic Rankine cycle power generation system with toluene exhibits the best performance. The maximum enhancements of output power and thermal efficiency are 6.08% and 2.14%, respectively. Moreover, it is also concluded that both ambient temperatures and intercooled cycle gas turbine operating conditions are very important factors affecting the operating performances of organic Rankine cycle power generation system.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Masoud Behzad ◽  
Benjamin Herrmann ◽  
Williams R. Calderón-Muñoz ◽  
José M. Cardemil ◽  
Rodrigo Barraza

Purpose Volumetric air receivers experience high thermal stress as a consequence of the intense radiation flux they are exposed to when used for heat and/or power generation. This study aims to propose a proper design that is required for the absorber and its holder to ensure efficient heat transfer between the fluid and solid phases and to avoid system failure due to thermal stress. Design/methodology/approach The design and modeling processes are applied to both the absorber and its holder. A multi-channel explicit geometry design and a discrete model is applied to the absorber to investigate the conjugate heat transfer and thermo-mechanical stress levels present in the steady-state condition. The discrete model is used to calibrate the initial state of the continuum model that is then used to investigate the transient operating states representing cloud-passing events. Findings The steady-state results constitute promising findings for operating the system at the desired airflow temperature of 700°C. In addition, we identified regions with high temperatures and high-stress values. Furthermore, the transient state model is capable of capturing the heat transfer and fluid dynamics phenomena, allowing the boundaries to be checked under normal operating conditions. Originality/value Thermal stress analysis of the absorber and the steady/transient-state thermal analysis of the absorber/holder were conducted. Steady-state heat transfer in the explicit model was used to calibrate the initial steady-state of the continuum model.


Author(s):  
Sudi Mungkasi

We consider the problem of drug diffusion in the dermal layer of human body. Two existing mathematical models of the drug diffusion problem are recalled. We obtain that the existing models lead to inconsistent equations for the steady state condition. We also obtain that solutions to the existing models are unrealistic for some cases of the unsteady state condition, because negative drug concentrations occur due to the inappropriate assumption of the model. Therefore, in this paper, we propose a modified mathematical model, so that the model is consistent, and the solution is nonnegative for both steady and unsteady state conditions of the drug diffusion problem in the dermal layer of human body. For the steady state condition, the exact solution to the proposed model is given. For unsteady state condition, we use a finite difference method for solving the models numerically, where the discretisation is centred in space and forward in time. Simulation results confirm that our proposed model and method preserve the non-negativity of the solution to the problem, so the solution is more realistic than that of the old model.


Author(s):  
George Rocha ◽  
Simon Reynolds ◽  
Theresa Brown

Solar Turbines Incorporated has combined proven technology and product experience to develop the new Taurus 65 gas turbine for industrial power generation applications. The single-shaft engine is designed to produce 6.3 megawatts of electrical power with a 33% thermal efficiency at ISO operating conditions. Selection of the final engine operating cycle was based on extensive aerodynamic-cycle studies to achieve optimum output performance with increased exhaust heat capacity for combined heat and power installations. The basic engine configuration features an enhanced version of the robust Centaur®50 air compressor coupled to a newly designed three-stage turbine similar to the Taurus 70 turbine design. Advanced cooling technology and materials are used in the dry, lean-premix annular combustor, consistent with Solar’s proven SoLoNOx™ combustion technology, capable of reducing pollutant emissions while operating on standard natural gas or diesel liquid fuels. Like the Titan™ 130 and Taurus 70 products, a traditional design philosophy has been applied in development of the Taurus 65 gas turbine by utilizing existing components, common technology and product experience to minimize risk, lower cost and maximize durability. A comprehensive factory test plan and extended field evaluation program was used to validate the design integrity and demonstrate product durability prior to full market introduction.


Author(s):  
Maurizio De Lucia ◽  
Carlo Lanfranchi ◽  
Antonio Matucci

A cogeneration plant with a small gas turbine was installed in a pharmaceutical factory and instrumented for acquiring all the values necessary to appraise both its energetic and cost advantages. The plant was designed and built as a demonstrative project under a program for energy use improvement in industry, partially financed by the European Union. The system comprises as its main components: 1) a gas turbine cogeneration plant for production of power and thermal energy under the form of hot water, superheated water, and steam; 2) a two-stage absorption unit, fueled by the steam produced in the cogeneration plant, for production of cooling thermal energy. The plant was provided with an automatized control system for the acquisition of plant operating parameters. The large amount of data thus provided made it possible to compare the new plant, under actual operating conditions, with the previously existing cooling power station with compression units, and with a traditional power plant. This comparative analysis was based on measurements of the plant operating parameters over nine months, and made it possible to compare actual plant performance with that expected and ISO values. The analysis results reveal that gas turbine performance is greatly affected by part-load as well as ambient temperature conditions. Two-stage absorber performance, moreover, turned out to decrease sharply and more than expected in off-design operating conditions.


Author(s):  
Y. G. Li

Most gas turbine performance analysis based diagnostic methods use the information from steady state measurements. Unfortunately, steady state measurement may not be obtained easily in some situations, and some types of gas turbine fault contribute little to performance deviation at steady state operating conditions but significantly during transient processes. Therefore, gas turbine diagnostics with transient measurement is superior to that with steady state measurement. In this paper, an accumulated deviation is defined for gas turbine performance parameters in order to measure the level of performance deviation during transient processes. The features of the accumulated deviation are analysed and compared with traditionally defined performance deviation at a steady state condition. A non-linear model based diagnostic method, combined with a genetic algorithm (GA), is developed and applied to a model gas turbine engine to diagnose engine faults by using the accumulated deviation obtained from transient measurement. Typical transient measurable parameters of gas turbine engines are used for fault diagnostics, and a typical slam acceleration process from idle to maximum power is chosen in the analysis. The developed diagnostic approach is applied to the model engine implanted with three typical single-component faults and is shown to be very successful.


1993 ◽  
Vol 115 (3) ◽  
pp. 554-562 ◽  
Author(s):  
L. H. Cowell ◽  
K. O. Smith

Development of a lean-premixed, liquid-fueled combustor is in progress to achieve ultra-low NOx emissions at typical gas turbine operating conditions. A filming fuel injector design was tested on a bench scale can combustor to evaluate critical design and operating parameters for low-emissions performance. Testing was completed using No. 2 diesel. Key design variables tested include premixing length, swirler angle, injector centerbody diameter, and reduced liner cooling. NOx emissions below 12 ppmv at 9 bar pressure were measured. Corresponding CO levels were 50 ppmv. An optimized injector design was fabricated for testing in a three injector sector of an annular combustor. Operating parameters and test results are discussed in the paper.


Author(s):  
Lemnouer Chibane

Steam reforming of methanol over Cu/ZnO/Al2O3 catalyst was theoretically studied under created unsteady state. A mathematical approach was proposed to evaluate the effect of periodic inputs on reactor performance. The efficacy of the periodic separating reactor in term of pure hydrogen and of methanol conversion was measured during the reaction of methanol steam reforming. The obtained results showed that under certain operating conditions the periodic operation can be used advantageously to increase the reactor ability up to a level higher than the maximal steady-state. Moreover, our findings showed that the pumping of hydrogen through the membrane was stimulated by the effect of periodic operations. The predicted results suggested that the created unsteady state mode by using a square wave function could give the better performances compared to the sinusoidal mode. Copyright © 2018 BCREC Group. All rights reservedReceived: 15th July 2017; Revised: 26th November 2017; Accepted: 8th December 2017; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Chibane, L. (2018). Simulation Study of a Membrane Reactor for Ultrapure Hydrogen Recovery from Methanol Steam Reforming Reaction under Periodic Steady-State. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 275-285 (doi:10.9767/bcrec.13.2.1340.275-285) 


Author(s):  
Shintaro Kumano ◽  
Naotaka Mikami ◽  
Kuniaki Aoyama

Power plant owners require their plants’ high reliability, availability and also reduction of the cost in today’s power generation industry. In addition, the power generation industry is faced with a reduction of experienced operators and sophistication of power generation equipment. Remote monitoring service provided by original equipment manufacturers (OEMs) has become increasingly popular due to growing demand for both improvement of plant reliability and solution of experienced operator shortage. Through remote monitoring service, customers can benefit from swift and appropriate operational support based on OEM’s know-how. Before implementation of remote monitoring, the customer and OEM often required repeated interchanges of information about operation and instrumentation data. These interchanges took a lot of time. Data analysis and estimation of deterioration were time-consuming. Remote monitoring has enabled us, OEMs, not only to access to a plant’s real-time information but also to trace the historical operation data, and therefore the required time of data analysis and improvement has been reduced. Mitsubishi Heavy Industries, Ltd. also embarked on around-the-clock remote monitoring service for gas turbine plant over a decade ago and has increased its ability over time. At present, the application of remote monitoring systems have been extended not only into proactive maintenance by making use of diagnostic techniques carried out by expert engineers but also into building a pattern recognition system and an artificial intelligence system using expert’ knowledge. Conventional diagnostics is only determining whether the plant is being operated within the prescribed threshold levels. Pattern recognition is a state-of-the-art technique for diagnosing plant operating conditions. By comparing past and present conditions, small deterioration can be detected before it needs inspection or repair, while all the operating parameter is within their threshold levels. Mahalanobis-Taguchi method (MT method) is a technique for pattern recognition and has the advantage of diagnosing overall GT condition by combining many variables into one indicator called Mahalanobis distance. MHI has applied MT method to the monitoring of gas turbines and verified it to be efficient method of diagnostics. Now, in addition to the MT method, automatic abnormal data discrimination system has been developed based on an artificial intelligence technique. Among a lot of artificial intelligence techniques, Bayesian network mathematical model is used.


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