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Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reheating furnaces are used to uniformly heat billets (blooms, billets, or slabs) to between 1000°C and 1300°C before hot rolling. Cascade control is widely used in temperature controllers of the reheating furnace. Unfortunately, the relationship between temperature indicator controllers (TIC) and flow indicator controllers (FIC) usually changes with a single slope. It means that temperature load disturbances cannot be effectively resolved. In this study, the relationship between TIC and FIC is proposed to be nonlinear with multiple slopes, which is used to accelerate the temperature response and increase the temperature stability under high or low load conditions. The temperature controller parameters are more diverse, so this study optimizes the temperature controller parameters and determines the characteristic curves between TIC and FIC effectively and quickly by using the Taguchi method. The performance of the multi-slope method and the single-slope method is evaluated in an actual heating furnace. The experimental results show that the proposed method in this study improves the mean square error and standard deviation by 33.76% and 22.44%, respectively. After commissioning, the parameter combination (including the characteristic curve) has a remarkable performance in the heating zone, which can be used to reduce temperature disturbance, accelerate the temperature response, and increase temperature stability in the reheating furnace.

In a thermal plant, the combustion system of the coal-fired boiler is a nonlinear time-varying system, which leads to undesired responses, if traditional proportional-integral-derivative controllers are utilized. Internal process delay is an important characteristic of the steam pressure in the boiler of coal-fired power plants, which affects the closed-loop dynamics. To compensate for this significant delay and reach the desired performance, a novel control strategy based on a combination of an optimal fractional-order proportional-integral-derivative (OFOPID) controller with a Smith predictor (SP) structure is suggested in this paper that achieves the desired control performance required for the optimal operation of the boiler. The simulation results of a coal-fired power plant boiler with the power of 300 MW show that the performance is improved considerably by having lower overshoot and lower rise and settling times, as well as a lower mean square error during the operation of the power plant Boiler. [ABSTRACT FROM AUTHOR]

The use of fuels with tendencies to reduce carbon dioxide emissions, particularly gaseous fuels, and improve combustion systems is one of the directions for increasing an internal combustion engine's attractiveness as a power source. This article presents the effects of combining natural gas combustion with a multi-stage combustion system. A two- and three-stage lean charge combustion system was proposed in order to increase the energy system efficiency. In order to achieve this, a single-cylinder test engine was used, with two interchangeably implemented combustion systems. The tests were carried out with two values of the excess air coefficient (λ = 1.3 and λ = 1.5), as well as two different fuel dose values (qo = 0.35 and 0.55 mg/inj), injected into the prechamber at the same indicated mean effective pressure value (IMEP = 6.5 bar) and the same engine speed (n = 1500 rpm). Based on the obtained research results, it was found that the use of a three-stage system limited the maximum combustion pressure and heat release rate due to the increased resistance of flows between the chambers. At the same time, it was found that the increase in the engine's indicated efficiency took place in a two-stage system, regardless of the excess air coefficient. Changing the dose of fuel fed into the prechamber significantly affects the engine performance (and efficiency) but only in the two-stage combustion system. [ABSTRACT FROM AUTHOR]

The structure of large biomass circulating fluidized bed (BCFB) boilers is complex, and control schemes for coal-fired boilers cannot be simply applied to biomass boilers. Multivariable coupling and operational disturbances are also common issues. In this study, a state space model of a 130 t/h BCFB boiler was established under different operating conditions. Using the 100% operating point as an example, a model predictive controller was designed and tested under output disturbance and input disturbance conditions. The results show that the predictive control system designed in this study has a fast response speed and good stability. [ABSTRACT FROM AUTHOR]

The development of modern vehicle drives is aimed at reducing fuel consumption (i.e., crude oil) and minimizing the exhaust emission of toxic components. One such development is the implementation of a two-stage combustion system. Such a system initiates ignition in the prechamber, and then the burning mixture flows into the main chamber, where it ignites the lean mixture. The system allows the efficient combustion of lean mixtures, both liquid and gaseous fuels, in the cylinder. This article proposes a solution for internal combustion engines with a cylinder capacity of approx. 500 cm3. The tests were carried out on a single-cylinder engine powered by pure methane supplied through a double, parallel injection system. A wide range of charge ignitability requires the use of an active chamber containing an injector and a spark plug. The tests were carried out at n = 1500 rpm with three load values (indicated mean effective pressure, IMEP): 2, 4 and 6 bar. All of these tests were carried out at a constant value of the center of combustion (CoC), 8 deg CA. This approach resulted in the ignition timing being the control signal for the CoC. As a result of the conducted research, it was found that an increase in the load, which improved the inter-chamber flow, allowed for the combustion of leaner mixtures without increasing the coefficient of variation, CoV(IMEP). The tests achieved a lean mixture combustion with a value of λ = 1.7 and an acceptable level of non-uniformity of the engine operation, CoV(IMEP) < 8%. The engine's indicated efficiency when using a two-stage system reached a value of about 42% at λ = 1.5 (which is about 8 percentage points more than with a conventional combustion system at λ = 1.0). [ABSTRACT FROM AUTHOR]

Reheating furnaces are used to homogeneously reheat the steel stock (Billets, blooms or slabs) at a temperature between 1000°C and 1250°C before hot rolling. Supply of accurate, stable, and reliable control of temperature is most important for reheating furnaces in hot-rolled steel production. The phenomenon of large time lags in temperature is an arduous problem that existed in the combustion system of furnaces, it causes control system big overshoot, continuous oscillation, and may even make the system unstable. In this paper, a prediction model based on gate recurrent unit (GRU) was established to forecast the inside temperature of the furnace by using temperature, fuel, and air time series. Moreover, this paper presents an approach which is combining a prediction model with a feedforward controller that can improve the stability of the temperature control system. Established prediction model of temperatures by collecting data from on-side, and evaluated the model and feedforward performance on the actual reheating furnace. Compared with other dynamic models (recurrent neural network and long short-term memory), the proposed models outperformed by 15.63% and 26.07% on average in terms of the mean absolute error and root mean square error, respectively. Moreover, the proposed control improve traditional PI controller by 33.43% and 19.92% on average in terms of the mean absolute error and root mean square error, respectively. The presented method can be used to reduce the temperature disturbances in the reheating furnaces.

• Combustion systems and aviation adaptability in piston engines are analyzed. • The key technologies related to in-cylinder combustion research are summarized. • Combustion characteristics and aviation adaptability of fuels are examined. • Future development directions of combustion technology are analyzed and predicted. The in-cylinder combustion process is a focus on research on heavy fuel aviation piston engine (HF-APE), which is quite significant because of its strong correction with engine's power and economic performance, as well as the level of emissions. This study reviews the representative combustion types of HF-APE in recent years, and comprehensively analyzes their aviation adaptability from various aspects. A review was conducted from the perspective of visualization measurement, combustion analysis, and high-altitude simulation technologies, all of which are the crucial methods to study the HF-APE combustion process. A comparative study was investigated on the combustion characteristics and aviation adaptability under different fuels. To meet the requirements of airworthiness regulations and the development of general aviation for more energy saving and environmental protection, further summarizing the progress as well as predicting the trends of HF-APE combustion technologies, are expected to be promoted due to their valuable scientific significance and engineering applications. [ABSTRACT FROM AUTHOR]

The use of fuels with tendencies to reduce carbon dioxide emissions, particularly gaseous fuels, and improve combustion systems is one of the directions for increasing an internal combustion engine’s attractiveness as a power source. This article presents the effects of combining natural gas combustion with a multi-stage combustion system. A two- and three-stage lean charge combustion system was proposed in order to increase the energy system efficiency. In order to achieve this, a single-cylinder test engine was used, with two interchangeably implemented combustion systems. The tests were carried out with two values of the excess air coefficient (λ = 1.3 and λ = 1.5), as well as two different fuel dose values (qo = 0.35 and 0.55 mg/inj), injected into the prechamber at the same indicated mean effective pressure value (IMEP = 6.5 bar) and the same engine speed (n = 1500 rpm). Based on the obtained research results, it was found that the use of a three-stage system limited the maximum combustion pressure and heat release rate due to the increased resistance of flows between the chambers. At the same time, it was found that the increase in the engine’s indicated efficiency took place in a two-stage system, regardless of the excess air coefficient. Changing the dose of fuel fed into the prechamber significantly affects the engine performance (and efficiency) but only in the two-stage combustion system.

The structure of large biomass circulating fluidized bed (BCFB) boilers is complex, and control schemes for coal-fired boilers cannot be simply applied to biomass boilers. Multivariable coupling and operational disturbances are also common issues. In this study, a state space model of a 130 t/h BCFB boiler was established under different operating conditions. Using the 100% operating point as an example, a model predictive controller was designed and tested under output disturbance and input disturbance conditions. The results show that the predictive control system designed in this study has a fast response speed and good stability.

Two-stroke engines have higher power density than traditional four-stroke engines, and therefore are suitable for engine downsizing. In this work, a four-stroke single-cylinder diesel engine is modified for two-stroke operation, and the combustion system is designed and optimized using a 3D simulation. Three different combustion chamber profiles and injection spray angles are compared to determine an optimized combustion system. The engine test results show that the two-stroke engine equipped with the newly designed combustion system is able to achieve the same effective power output at a much lower speed than the original four-stroke engine, as well as obtain a better indicated thermal efficiency. This indicates that the poppet-valve two-stroke engine could be an effective technical approach for engine downsizing. [ABSTRACT FROM AUTHOR]

A diesel engine has been widely used in ground transportation, agricultural machinery, and sea shipments, due mainly to its excellent reliability and high thermal efficiency. However, the fuel emission and consumption of diesel engines have posed a great threat to the ecological environment in recent years. Therefore, it is very necessary to improve the combustion and emission performance of diesel engines, further to meet the specific requirement of national environmental regulations. Diffusion combustion can generally dominate the combustion process in the direct injection diesel engine. The mixing quality of fuel and air can be expected to serve as the most effective means for the higher performance of diffusion combustion. Different techniques have also emerged to optimize the combustion quality of the fuel/air mixing process in modern diesel engines. For instance, the special geometry structure of the combustion chamber has been adopted to utilize the momentum of the high-pressure fuel jet in the wall-flow-guided combustion system, where the diffusion can be guided in the chamber by the effect of the spray jet hitting the wall. As such, the air utilization rate can be improved for the high combustion and emission performance of a direct injection diesel engine. Both lateral swirl combustion system (LSCS) and separated swirl combustion system (SSCS) have been specially designed for the wall diversion structure in the combustion chamber, where the spray in the cylinder can be guided to form a swirl motion for the high quality of fuel/air mixing process. Nevertheless, the two combustion systems behave in different in-cylinder fuel spray strategies. In this study, a single-cylinder diesel engine was selected to verify the combustion performance of the LSCS and SSCS under different loads and excess air coefficients. AVL Fire software was used to explore the fuel/air mixing mechanism of the combustion system. The test results show that the fuel consumption rate, soot emission, and combustion duration of LSCS under various loads were reduced by 2.4-7.8 g/(kW·h), 2.7-3.9 FSN, and 5.6-10.7 °CA, respectively, compared with the SSCS. Under different excess air coefficients, the fuel consumption rate, soot emission, and duration of combustion were reduced by 3.2-9.8 g/(kW·h), 2.3-3.8 FSN, and 7.9-10.0 °CA, respectively. The maximum drop of LSCS in the fuel consumption and soot emission were 4.3%, and 87.0%, respectively. The simulation results show that the spray jet impinged the convex edge in the LSCS, leading to the wall jets scrolling to form two lateral swirls. The two adjacent spray jets produced the wall jet interference, when flowing out of the convex edge, further improving the air utilization rate. By contrast, there was the fuel aggregation, as the position of the spray jet touched the wall, particularly when the piston was moving down in the SSCS, which was not conducive to the fuel/air mixing process. That is why the air entrainment quantity of the LSCS increased by 9.3%, compared with the SSCS. There was a smaller fuel mass ratio in the interval of equivalent ratio 2-4, whereas, the larger in the interval of equivalent ratio <1-2, indicating the better uniform fuel/air mixing of the LSCS. Therefore, the LSCS can be widely expected to outstandingly improve the fuel/air mixing process, and the combustion performance of the direct injection diesel engine with less soot generation. The finding can provide a technical reference for the structural design and optimization of the combustion chamber in the direct injection diesel engine. [ABSTRACT FROM AUTHOR]

Air-fuel ratio is an important parameter in high-temperature and high-speed heat-airflow test system. If air-fuel ratio of the system is too low, the fuel cannot be fully burned, which will not only reduce the control performance of the gas temperature, but also increase the pollutant emissions of the combustor. In order to solve this problem, it is necessary to identify the air-fuel ratio of the system, get the prediction model of the air-fuel ratio, and adjust the fuel input according to the prediction value of the air-fuel ratio. In order to realize the accurate identification of the air-fuel ratio of the system, this paper briefly analyses the mathematical model of the air-fuel ratio in high-temperature and high-speed heat-airflow test system, and proposes an identification method of the air-fuel ratio based on support vector machine. On the basis of the experimental data, the air-fuel ratio of the system is identified by using different kernels, i.e. firstly, the experimental scheme is designed, and the fuel mass flow rate, air mass flow rate, gas temperature and actual air-fuel ratio of the system are collected under different experimental conditions; then, the collected data are divided into training datasets and test datasets, and the training datasets are trained by support vector machine to obtain identification model of the air-fuel ratio; finally, the identification model is validated with test datasets under different conditions, and the accuracy of the model is obtained. The identification results show that the support vector machine has good identification performance and can accurately approximate the actual dynamic process of the air-fuel ratio. The average absolute error of the identification model is less than 0.05, and the average relative error is less than 0.5% when the test datasets are smaller than the training datasets.

The development of modern vehicle drives is aimed at reducing fuel consumption (i.e., crude oil) and minimizing the exhaust emission of toxic components. One such development is the implementation of a two-stage combustion system. Such a system initiates ignition in the prechamber, and then the burning mixture flows into the main chamber, where it ignites the lean mixture. The system allows the efficient combustion of lean mixtures, both liquid and gaseous fuels, in the cylinder. This article proposes a solution for internal combustion engines with a cylinder capacity of approx. 500 cm3. The tests were carried out on a single-cylinder engine powered by pure methane supplied through a double, parallel injection system. A wide range of charge ignitability requires the use of an active chamber containing an injector and a spark plug. The tests were carried out at n = 1500 rpm with three load values (indicated mean effective pressure, IMEP): 2, 4 and 6 bar. All of these tests were carried out at a constant value of the center of combustion (CoC), 8 deg CA. This approach resulted in the ignition timing being the control signal for the CoC. As a result of the conducted research, it was found that an increase in the load, which improved the inter-chamber flow, allowed for the combustion of leaner mixtures without increasing the coefficient of variation, CoV(IMEP). The tests achieved a lean mixture combustion with a value of λ = 1.7 and an acceptable level of non-uniformity of the engine operation, CoV(IMEP) < 8%. The engine’s indicated efficiency when using a two-stage system reached a value of about 42% at λ = 1.5 (which is about 8 percentage points more than with a conventional combustion system at λ = 1.0).

This paper discusses the multiscale asymptotic expansion for combustion system with composite materials or porous media in thermal protection system. The combustion system consists of two nonlinear equations with rapidly oscillating coefficients, which are posed on a time-varying domain and computationally expensive to solve with the finite element method. To efficiently solve this system, we propose the standard/novel multiscale asymptotic expansions by combining them with boundary layer solutions. Numerical simulation is performed to validate the accuracy and efficiency of the newly proposed methods, which show that the novel multiscale asymptotic expansion is more accurate than the standard one. • We introduce multiscale asymptotic expansions to solve combustion system. • Our multiscale asymptotic expansion enables derivation of more accurate solutions. • To capture the domain boundary, we propose a boundary layer problem. [ABSTRACT FROM AUTHOR]

• Developed a universal gas turbine circumferential temperature distribution model for combustion system fault detection. • Revealed the influence modes of interference factors and faults on EGT distribution. • Proposed a combustion system fault detection method based on EGT dispersion. • Validated the effectiveness of the revealed rules and proposed method with actual operational data. The gas turbine combustion system operates under harsh conditions, and any faults such as nozzle clogging, cracks, etc. can endanger the downstream components and cause catastrophic accidents. Thus, monitoring the combustion system status and detecting its performance degradation timely are crucial for gas turbine safety. The current predominant method for monitoring involves analyzing exhaust gas temperature (EGT) dispersion, utilizing thermocouples placed at the turbine outlet to indirectly assess combustion system performance. However, the EGT is affected not only by faults but also by various non-fault disturbances, such as operational conditions, atmospheric variations, compressor performance degradation, and uneven hot gas mixing and rotating. To improve the sensitivity of fault detection, it is necessary to investigate how various factors affect the EGT dispersion and differentiate between EGT changes due to interference and those due to combustion system faults. However, using actual operational data from gas turbines to analyze and reveal these impact mechanisms is challenging. Therefore, this paper develops a gas turbine model for combustion system fault detection that accurately reflects the uneven circumferential distribution of EGT. The model incorporates a multi-combustor burner, a multi-channel turbine, and a module for simulating the mixing and rotating of the hot gas. Using this model, simulations are conducted to study the effects of non-fault interference factors, such as variations in ambient temperature, fuel flow changes, and compressor performance degradation, on EGT distribution. Additionally, simulations are conducted to analyze the effects of faults, including combustor cracks, uneven fuel distribution, and the coupling of interferences with faults, on EGT distribution. By comparing the normal and abnormal modes, the study reveals the different EGT responses due to non-fault interferences and combustion system faults. Based on these findings, a fault detection method for coupled conditions is proposed. The research results provide a basis for the fault detection of combustion system, enabling practitioners to reduce interference in fault detection and to increase the detection sensitivity. [ABSTRACT FROM AUTHOR]

With the increasing demands on the environment, the rational treatment and disposal of garbage is playing an important role in practicing the concept of green development and promoting the construction of ecological civilization. This view of "garbage is a resource placed in the wrong place" is gaining more and more recognition. Municipal solid waste (MSW) incineration power generation technology as a method of solid waste utilization has evolved into a mature resource utilization technology. This paper compares the domestic and international MSW incineration technologies from the top, middle and lower reaches of the waste incineration power generation industry, namely the characteristics of MSW, combustion technology and flue gas control. The results show MSW incineration technology is still an indispensable means to achieve waste reduction and resource reduction. However, it is necessary to upgrade the incineration techno-logy, improve the MSW incineration process, strictly control the emission of pollutants in the incineration flue gas, and establish real-time monitoring points to avoid secondary pollution.

The cycle-to-cycle variations (CCVs) in reciprocating internal combustion engines may cause negative influence on diving performance, fuel economy, and emissions. Especially, lean-burn technology or exhaust gas recirculation (EGR) was used to improve engine combustion efficiency and reduce NOx, and the combustion boundary was limited by increased CCVs. Therefore, it was important to identify the complex dynamics of CCVs and to take measures for inhibiting them. The CCVs based on indicated mean effective pressure (IMEP) time series were examined in a lean-burn natural gas engine with a non-uniform pre-mixture based on statistical and multifractal theories. Tests were conducted at an engine speed of 1000 rpm and low loads of 10% and 25%, and combustion data at an engine load of 10% were analysed in detail because the CCVs are less sensitive to changes of gas injection timing (GIT) at the higher engine load. The nonlinear dynamics of the CCVs was revealed at the different GIT from 1° to 120°CA ATDC. The statistical properties of IMEP time series were characterised by distributions of probability density functions (PDF), the multifractal complexities of the combustion fluctuations were quantitatively analysed by the singularity spectra in terms of the Hölder exponent based on the theory of wavelet transform modulus maxima, and the primary source leading to the increased CCVs and complex dynamics in a natural gas engine with a non-uniform pre-mixture was identified using 3D-computational fluid dynamics simulations. Results show that as the GIT increased, the kurtosis of the IMEP time series systematically decreased from 592 to 1.8, the fast dynamics transitions from super-Gaussian to quasi-Gaussian distributions in combustion system were revealed, and the lower value of kurtosis implied the lower degree of intermittency. Except for the GIT of 60°CA ATDC, the value of the Hölder exponent h 0 > 0.5 , which implies that the CCVs for the other GITs behaved like a persistent walk or positive correlation. For GITs of 60° and 90°CA ATDC, the narrow broadness of the singularity spectrum implicated a monofractality, while the obvious multifractal properties could be identified for the other GITs. The transitions of the dynamic behaviours may be caused by the degree of mixture in-homogeneity combined with a new mechanism of "prior-cycle effects" proposed in this paper, and the effect mechanism was not only associated with the residual gas in the cylinder but also with the residual gas fuel in the intake port, rather than independent effect of residual gas in cylinder reported in previous researches. Our research results provided the deeper understanding on the dynamics of combustion system in multi-point injection natural gas engines and may be beneficial to achieve nonlinear prediction and to develop improved control strategies for inhibiting the CCVs. [ABSTRACT FROM AUTHOR]

Two-stroke engines have higher power density than traditional four-stroke engines, and therefore are suitable for engine downsizing. In this work, a four-stroke single-cylinder diesel engine is modified for two-stroke operation, and the combustion system is designed and optimized using a 3D simulation. Three different combustion chamber profiles and injection spray angles are compared to determine an optimized combustion system. The engine test results show that the two-stroke engine equipped with the newly designed combustion system is able to achieve the same effective power output at a much lower speed than the original four-stroke engine, as well as obtain a better indicated thermal efficiency. This indicates that the poppet-valve two-stroke engine could be an effective technical approach for engine downsizing.

In order to understand and improve the oil and gas mixing performance of a dual-channel vortex chamber diesel engine, the BH175F dual-channel vortex chamber combustion system was used as the research foundation, and the oil-gas mixture process of the combustion system was numerically analyzed. By analyzing the cylinder temperature, cylinder pressure, mixing process and combustion process of the combustion system, the mixture performance of the combustion system was studied. Results indicated that: The mixture of the compression Top Dead Center (TDC) started to enter the main combustion chamber through the start-up hole; when the piston reached 4° After Top Dead Center (ATDC), the mixture started to enter the main combustion chamber through the connecting channels A and B, and the high-concentration mixture entered the main combustion from the start-up hole; when the piston continued running down to 20° and 25° ATDC, it could be seen that the main combustion chamber mixture was already relatively uniform; besides, when the equivalence ratio was between 0.8 and 1, the air-fuel mixture was unevenly distributed in the main combustion chamber. It provides guidance for further improvement of the combustion system. [ABSTRACT FROM AUTHOR]

During coal-fired power generation, uniform combustion temperature in the boiler is desired which will benefit both economical efficiency and pollution reduction. To this end, a model predictive control (MPC) algorithm based on the Nonlinear Auto-Regressive Exogenous Inputs (NARX) neural network and KS-function is proposed, and the uniform combustion in the boiler is realized by controlling the opening travel of secondary windgates. In the modeling process, a multi-input and multi-output(MIMO) NARX neural network is developed using the historical data of the real system The NARX neural network is then used to predict the state variables, and the optimal control input is achieved by applying sequential quadratic programming (SQP), comparing with linear MPC the mean temperature difference is reduced by 64.2%. In addition, this paper proposes a new method to reduce the computational time of the online optimization process based on KS-function, which greatly accelerates the searching speed of SQP by 67.3%. The proposed MPC algorithm is applied to a 660 MW power generating unit. The results show that by applying the proposed algorithm, the temperature difference in the boiler is kept within 100 °C, the average coal consumption of the power plant is reduced by 5.71 g/kWh, and the NOx emission is reduced to 23.84 mg/m 3. It can be concluded that the proposed algorithm greatly improves the economical efficiency of the power plant and reduces the emission of pollutants. • Apply model predictive control (MPC) algorithm on coal-fired power generation and achieve homogeneous combustion. • Use NARX model to predict the future output in an iteration way, improve stability of the system. • Use KS-function to greatly reduce the computational time of online optimization process and accelerate the speed of online MPC process. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As one of the core components of gas turbines, the combustion system operates in a high-temperature and high-pressure adverse environment, which makes it extremely prone to faults and catastrophic accidents. Therefore, it is necessary to monitor the combustion system to detect in a timely way whether its performance has deteriorated, to improve the safety and economy of gas turbine operation. However, the combustor outlet temperature is so high that conventional sensors cannot work in such a harsh environment for a long time. In practical application, temperature thermocouples distributed at the turbine outlet are used to monitor the exhaust gas temperature (EGT) to indirectly monitor the performance of the combustion system, but, the EGT is not only affected by faults but also influenced by many interference factors, such as ambient conditions, operating conditions, rotation and mixing of uneven hot gas, performance degradation of compressor, etc., which will reduce the sensitivity and reliability of fault detection. For this reason, many scholars have devoted themselves to the research of combustion system fault detection and proposed many excellent methods. However, few studies have compared these methods. This paper will introduce the main methods of combustion system fault detection and select current mainstream methods for analysis. And a circumferential temperature distribution model of gas turbine is established to simulate the EGT profile when a fault is coupled with interference factors, then use the simulation data to compare the detection results of selected methods. Besides, the comparison results are verified by the actual operation data of a gas turbine. Finally, through comparative research and mechanism analysis, the study points out a more suitable method for gas turbine combustion system fault detection and proposes possible development directions.

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)