Plasma-Assisted Reforming of Natural Gas for GTL: Part II—Modeling of the Methane–Oxygen Reformer

The utilisation of the thermal emissions of modern ship power plants requires the development and implementation of essentially new methods of using low-temperature waste heat. Thermoacoustic technologies are able to effectively use low-temperature and cryogenic heat resources with a potential difference of 500–111 K. Thermoacoustic heat machines (TAHMs) are characterised by high reliability, simplicity and environmental safety. The wide implementation of thermoacoustic energy-saving systems is hampered by the low specific power and the difficulties of directly producing mechanical work. An efficient approach to converting acoustic energy into mechanical work entails the utilisation of axial pulse bidirectional turbines within thermoacoustic heat engines. These thermoacoustic turbogenerators represent comprehensive systems that consist of thermoacoustic primary movers with an electric generator actuated by an axial-pulse bidirectional turbine. The development of such a thermoacoustic turbogenerator requires several fundamental issues to be solved. For this purpose, a suitable experimental setup and a 3D computational fluid dynamics (CFD) model of a thermoacoustic engine (TAE) with bidirectional turbines were created. The research program involved conducting physical experiments and the CFD modelling of processes in a TAE resonator with an installed bidirectional turbine. The boundary and initial conditions for CFD calculations were based on empirical data. The adequacy of the developed numerical model was substantiated by the results of physical experiments. The CFD results showed that the most significant energy losses in bidirectional turbines are manifested in the output grid of the turbine.

Section: Cfd Simulation Resultsmentioning

confidence: 99%

Exploration of a Model Thermoacoustic Turbogenerator with a Bidirectional Turbine

Korobko,

Serbin,

2023

“…This method provides a procedure for numerical integration of the differential equations, which describe the reacting viscous gas flows. A 3D model of the reacting flows has been used which enables the prediction of the plasma-chemical influence and optimisation parameters taking into consideration mixing, turbulence, radiation, and combustion features [24][25][26].…”

Section: Mathematical Modellingmentioning

confidence: 99%

Investigation of the Efficiency of a Dual-Fuel Gas Turbine Combustion Chamber with a Plasma‒Chemical Element

Serbin

Diasamidze

Dzida

et al. 2023

The study is devoted to the possibility of increasing the efficiency of the working process in dual-fuel combustion chambers of gas turbine engines for FPSO vessels. For the first time, it is proposed to use the advantages of plasma‒chemical intensification of the combustion of hydrocarbon fuels in the dual-fuel combustion chambers, which can simultaneously operate on gaseous and liquid fuels. A design scheme of a combustion chamber with a plasma‒chemical element is proposed. A continuous type mathematical model of a combustion chamber with a plasma‒chemical element has been developed, which is based on the solution of a system of differential equations describing the processes of chemical reactions in a turbulent system, taking into consideration the initiating effect of the products of plasma‒chemical reactions on the processes of flame propagation. A modified six-stage kinetic scheme of hydrocarbon oxidation was used to simultaneously predict the combustion characteristics of the gaseous and liquid fuels, taking into account the decrease in the activation energy of carbon monoxide oxidation reactions when the products of the plasma‒chemical element are added. The results reveal that the addition of plasma‒chemical products significantly reduces CO emissions in the outlet section of the flame tube (from 25‒28 ppm to 3.9‒4.6 ppm), while the emission of nitrogen oxides remains practically unchanged for the studied combustion chamber. Further research directions are proposed to enhance the working process efficiency of a dual-fuel combustion chamber for gas turbine engines as part of the power plant of FSPO vessels.

“…The performance of a dual-fuel combustion chamber can be improved by using various combustion intensifiers, including plasma-chemical devices [34][35][36][37]. This is especially important when working on liquid fuel, when there is a need for additional stabilisation of the flame front and an increase in the rate of combustion of evaporating fuel.…”

Section: Fig 5 Distribution Of the Temperatures (K) Along The Length Of The Lowemission Combustion Chamber For Different Modes Of Fuel Sumentioning

confidence: 99%

Investigations of the Emission Characteristics of a Dual-Fuel Gas Turbine Combustion Chamber Operating Simultaneously on Liquid and Gaseous Fuels

Serbin

Diasamidze

Gorbov

et al. 2021

This study is dedicated to investigations of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. As the object of the research, a low-emission gas turbine combustion chamber with partial premixing of fuel and air inside the outer and inner radial-axial swirls was chosen. The method of the research is based on the numerical solution of the system of differential equations which represent the physical process of mass and energy conservation and transformations and species transport for a multi-component chemically reactive turbulent system, considering nitrogen oxides formation and a discrete ordinates model of radiation. The chemistry kinetics is presented by the 6-step mechanism of combustion. Seven fuel supply operating modes, varying from 100% gaseous fuel to 100% liquid fuel, have been analysed. This analysis has revealed the possibility of the application of computational fluid dynamics for problems of dual-fuel combustion chambers for the design of a floating vessel’s gas turbine. Moreover, the study has shown the possibility of working in different transitional gaseous and liquid fuel supply modes, as they satisfy modern ecological requirements. The dependencies of the averaged temperature, NO, and CO concentrations along the length of the low-emission gas turbine combustion chamber for different cases of fuel supply are presented. Depending on the different operating modes, the calculated emission of nitrogen oxides NO and carbon monoxide CO at the outlet cross-section of a flame tube are different, but, they lie in the ranges of 31‒50 and 23‒24 mg/nm3 on the peak of 100% liquid fuel supply mode. At operating modes where a gaseous fuel supply prevails, nitrogen oxide NO and carbon monoxide CO emissions lie in the ranges of 1.2‒4.0 and 0.04‒18 mg/nm3 respectively.