Investigations of a Gas Turbine Low-Emission Combustor Operating on the Synthesis Gas

Investigations of the working processes in a gas turbine low-emission combustor operating on the synthesis gas, in which the principle of RQL (Rich-Burn, Quick-Mix, and Lean-Burn) combustion technology is realized, have been performed. Selected concept of a gas turbine combustor can provide higher performance and lower emission of nitrogen oxides and demonstrates satisfactory major key parameters. Obtained results and recommendations can be used for the gas turbine combustor operation modes modeling, geometry optimization, and prospective power generation units design and engineering

Research of low-emission associated gas combustion in the gas turbine engine of a floating production, storage and offloading system

Serbin, S. I. Research of low-emission associated gas combustion in the gas turbine engine of a floating production, storage and offloading system = Дослідження процесів низькоемісійного спалювання попутного газу в ГТД в складі плавучої системи видобутку, зберігання та вивантаження нафтопродуктів / S. I. Serbin, Yun Fei Wang // Зб. наук. пр. НУК. – Миколаїв : НУК, 2020. – № 1 (479). – P. 42–50.Анотація. Проведено аналіз можливостей організації низькоемісійного сталювання попутного газу в камері згоряння газотурбінного двигуна потужністю 25 МВт, що працює в складі плавучої системи видобутку, зберігання та вивантаження нафтопродуктів (FPSO). Одна з істотних проблем, яка вирішується при використанні газотурбінної техніки в складі FPSO, – задоволення екологічних вимог міжнародних організацій, особливо щодо викидів токсичних компонентів, таких як оксиди вуглецю та азоту. Запропоновано ефективний спосіб організації робочого процесу в газотурбінній низькоемісійній камері згоряння, що працює на різних видах газоподібного палива. З метою підвищення ефективності процесів у газотурбінній камері пропонується використовувати ідеї попереднього перемішування газоподібного палива із повітрям в аксіально-радіальних завихрювачах, а також значного збіднення паливо-повітряної суміші в об’ємі камери згоряння. Розроблено математичну модель газотурбінної камери згоряння з низьким рівнем викидів токсичних компонентів, яка дає змогу передбачити екологічні параметри паливоспалюючого пристрою в процесі використання попутного газу. Тривимірна математична модель вигоряння газоподібного палива в низькоемісійній камері згоряння ГТД містить рівняння: нерозривності, збереження кількості руху та енергії, переносу хімічних компонентів, утворення і розкладання оксидів азоту. Отримані результати показали певне погіршення екологічних параметрів камери згоряння при переході з природного на попутний газ та необхідність подальшої модифікації камери згоряння з попереднім частковим змішуванням палива та повітря при використанні попутного газу в системах FPSO. Отримано нові знання щодо організації робочого процесу в низькоемісійних камерах згоряння ГТД та вигоряння вищих вуглеводнів у газотурбінній камері.Abstract. The analysis of the possibilities of organization of low-emission associated gas combustion in the combustion chamber of a gas turbine engine with a capacity of 25 MW, which works as part of floating production, storage and offloading (FPSO) system is carried out. One of the significant problems that solved when using the gas turbine technology at FPSO is to satisfy the international environmental requirements, especially for emissions of toxic components, such as carbon and nitrogen oxides. An effective way of organizing a workflow in a gas turbine low-emission combustion chamber operating on different gaseous fuels is proposed. In order to increase the efficiency of the processes in the gas turbine chamber, it is proposed to use the ideas of pre-mixing of gaseous fuels with air in axial-radial swirlers, as well as significant leaning of the fuel-air mixture in the volume of the combustion chamber. A mathematical model of a low-emission gas turbine combustion chamber has been developed, which allows predicting the environmental parameters of a fuel-burning device when using associated gas. Three-dimensional mathematical model of gaseous fuels combustion in a low-emission gas turbine combustion chamber contains the following equations: continuity, conservation of momentum and energy, transfer of chemical components, formation and decomposition of nitrogen oxides. The obtained results showed certain deterioration in the environmental parameters of the combustion chamber when switching from natural to associated gas and the need for further modification of the combustion chamber with lean and partially premixed mixture of fuel and air when using associated gas on the FPSO vessels

Study of burning stability in low emission gas turbine combustor

Study of burning stability in low emission gas turbine combustor / S. Serbin, A. Kozlovskyi, K. Burunsuz, R. Radchenko // Contemporary Issues of Heat and Mass Transfer : monograph / T. Bohdal, M. Sikora. – Koszalin : Koszalin University of Technology, 2019. – Vol. 2. – P. 747–766.Introduction: The paper is devoted to investigation of gaseous fuel burning stability in low emission combustor of stationary gas turbine engine (GTE). The mathematical model of unsteady processes in GTE low emission combustor is developed. A methodology of numerical experiment concerning stability of gaseous fuel burning in low emission combustor with using complex of computational fluid dynamics (CFD) is proposed. Theoretical studies of non-stationary processes in a low emission gas turbine combustor were performed using the Large Eddy Simulation (LES) model of turbulence. The results of the model verification confirm its validity for the wide spectrum of fuel nozzle design. The performed 3D calculations allowed defining main pulsating features of a low emission gas turbine combustor. For the entire considered frequency range, a pronounced frequency of 189 Hz is traced, which is caused by combustion processes, as evidenced by the spectra of temperature fluctuations and the mass concentration of fuel. The calculated local mean square pulsations of the static pressure inside the combustion line can reach maximum values of about 11.5 kPa. The obtained results and recommendations can be used for modeling of unsteady processes in low emission combustor and stability improvement of GTE combustor with partially premixed lean fuel-air mixtures

Application of Thermo-chemical Technologies for Conversion of Associated Gas in Diesel-Gas Turbine Installations for Oil and Gas Floating Units

The paper considers the issue of thermo-chemical recovery of engine’s waste heat and its further use for steam conversion of the associated gas for oil and gas floating units. The characteristics of the associated gas are presented, and problems of its application in dual-fuel medium-speed internal combustion engines are discussed. Various variants of combined diesel-gas turbine power plant with thermo-chemical heat recovery are analyzed. The heat of the gas turbine engine exhaust gas is utilized in a thermo-chemical reactor and a steam generator. The engines operate on synthesis gas, which is obtained as a result of steam conversion of the associated gas. Criteria for evaluating the effectiveness of the developed schemes are proposed. The results of mathematical modeling of processes in a 14.1 MW diesel-gas turbine power plant with waste heat recovery are presented. The effect of the steam/associated gas ratio on the efficiency criteria is analyzed. The obtained results indicate relatively high effectiveness of the scheme with separate high and low pressure thermo-chemical reactors for producing fuel gas for both gas turbine and internal combustion engines. The calculated efficiency of such a power plant for considered input parameters is 45.6%

Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products

In this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight ratio and efficiency for diesel and gas turbine power modules of various capacities. Mathematical modeling methods are used to analyze the parameters of an alternative gas turbine unit based on steam conversion of the associated gas, and the estimated efficiency of the energy module is shown to be 50%. In the modeling of the burning processes, the UGT 25000 serial low emission combustor is considered, and a detailed analysis of the processes in the combustor is presented, based on the application of a 35-reaction chemical mechanism. We confirm the possibility of efficient combustion of associated gas steam conversion products with different compositions, and establish that stable operation of the gas turbine combustor is possible when using fuels with low calorific values in the range 7–8 MJ/kg. It is found that the emissions of NOx and CO during operation of a gas turbine engine on the associated gas conversion products are within acceptable limits

Investigations of the Working Process in a Dual-Fuel Low-Emission Combustion Chamber for an FPSO Gas Turbine Engine

This investigation is devoted to an analysis of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. The low-emission gas turbine combustion chamber with partial pre-mixing of fuel and air inside the outer and inner radial-axial swirlers was chosen as the object of research. When modelling processes in a dual-flow low-emission gas turbine combustion chamber, a generalized method is used, based on the numerical solution of the system of conservation and transport equations for a multi-component chemically reactive turbulent system, taking into consideration nitrogen oxides formation. The Eddy-Dissipation-Concept model, which incorporates Arrhenius chemical kinetics in a turbulent flame, and the Discrete Phase Model describing the interfacial interaction are used in the investigation. The obtained results confirmed the possibility of organizing efficient combustion of distillate liquid fuel in a low-emission gas turbine combustion chamber operating on the principle of partial preliminary formation of a fuel-air mixture. Comparison of four methods of liquid fuel supply to the channels of radial-axial swirlers (centrifugal, axial, combined, and radial) revealed the advantages of the radial supply method, which are manifested in a decrease in the overall temperature field non-uniformity at the outlet and a decrease in nitrogen oxides emissions. The calculated concentrations of nitrogen oxides and carbon monoxide at the flame tube outlet for the radial method of fuel supply are 32 and 9.1 ppm, respectively. The results can be useful for further modification and improvement of the characteristics of dual-fuel gas turbine combustion chambers operating with both gaseous and liquid fuels

Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products

In this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight ratio and efficiency for diesel and gas turbine power modules of various capacities. Mathematical modeling methods are used to analyze the parameters of an alternative gas turbine unit based on steam conversion of the associated gas, and the estimated efficiency of the energy module is shown to be 50%. In the modeling of the burning processes, the UGT 25000 serial low emission combustor is considered, and a detailed analysis of the processes in the combustor is presented, based on the application of a 35-reaction chemical mechanism. We confirm the possibility of efficient combustion of associated gas steam conversion products with different compositions, and establish that stable operation of the gas turbine combustor is possible when using fuels with low calorific values in the range 7–8 MJ/kg. It is found that the emissions of NOx and CO during operation of a gas turbine engine on the associated gas conversion products are within acceptable limits

Gas turbine unite inlet air cooling by using an excessive refrigeration capacity of absorption-ejector chiller in booster air cooler

Two-stage Gas turbine unite (GTU) inlet air cooling by absorption lithium-bromide chiller (ACh) to the temperature 15 °C and by refrigerant ejector chiller (ECh) to 10 °C through utilizing the turbine exhaust gas heat for changeable ambient air temperatures and corresponding heat loads on the air coolers for the south Ukraine climatic conditions is analysed. An excessive refrigeration capacity of combined absorption-ejector chiller (AECh) exceeding the current heat loads and generated at decreased heat loads on the air coolers at the inlet of GTU can be used for covering increased heat loads to reduce the refrigeration capacity of AECh. The GTU inlet air cooling system with an ambient air precooling booster stage and a base two-stage cooling air to the temperature 10 °C by AECh is proposed. The AECh excessive cooling capacity generated during decreased heat loads on the GTU inlet air coolers is conserved in the thermal accumulator and used for GTU inlet air precooling in a booster stage of air cooler during increased heat loads. There is AECh cooling capacity reduction by 50% due to the use of a booster stage for precooling GTU inlet ambient air at the expense of an excessive cooling capacity accumulated in the thermal storage

Investigations of the Working Process in a Dual-Fuel Low-Emission Combustion Chamber for an FPSO Gas Turbine Engine

This investigation is devoted to an analysis of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. The low-emission gas turbine combustion chamber with partial pre-mixing of fuel and air inside the outer and inner radial-axial swirlers was chosen as the object of research. When modelling processes in a dual-flow low-emission gas turbine combustion chamber, a generalized method is used, based on the numerical solution of the system of conservation and transport equations for a multi-component chemically reactive turbulent system, taking into consideration nitrogen oxides formation. The Eddy-Dissipation-Concept model, which incorporates Arrhenius chemical kinetics in a turbulent flame, and the Discrete Phase Model describing the interfacial interaction are used in the investigation. The obtained results confirmed the possibility of organizing efficient combustion of distillate liquid fuel in a low-emission gas turbine combustion chamber operating on the principle of partial preliminary formation of a fuel-air mixture. Comparison of four methods of liquid fuel supply to the channels of radial-axial swirlers (centrifugal, axial, combined, and radial) revealed the advantages of the radial supply method, which are manifested in a decrease in the overall temperature field non-uniformity at the outlet and a decrease in nitrogen oxides emissions. The calculated concentrations of nitrogen oxides and carbon monoxide at the flame tube outlet for the radial method of fuel supply are 32 and 9.1 ppm, respectively. The results can be useful for further modification and improvement of the characteristics of dual-fuel gas turbine combustion chambers operating with both gaseous and liquid fuels

Application of Thermo-chemical Technologies for Conversion of Associated Gas in Diesel-Gas Turbine Installations for Oil and Gas Floating Units

The paper considers the issue of thermo-chemical recovery of engine’s waste heat and its further use for steam conversion of the associated gas for oil and gas floating units. The characteristics of the associated gas are presented, and problems of its application in dual-fuel medium-speed internal combustion engines are discussed. Various variants of combined diesel-gas turbine power plant with thermo-chemical heat recovery are analyzed. The heat of the gas turbine engine exhaust gas is utilized in a thermo-chemical reactor and a steam generator. The engines operate on synthesis gas, which is obtained as a result of steam conversion of the associated gas. Criteria for evaluating the effectiveness of the developed schemes are proposed. The results of mathematical modeling of processes in a 14.1 MW diesel-gas turbine power plant with waste heat recovery are presented. The effect of the steam/associated gas ratio on the efficiency criteria is analyzed. The obtained results indicate relatively high effectiveness of the scheme with separate high and low pressure thermo-chemical reactors for producing fuel gas for both gas turbine and internal combustion engines. The calculated efficiency of such a power plant for considered input parameters is 45.6%