Reduction of Fuel Utilization Through Oxygen-Enriched Combustion in a Reheat Furnace Pusher-Type

Author(s):  
Francisco J. Martinez Zambrano ◽  
Armin K. Silaen ◽  
Kelly Tian ◽  
Joe Maiolo ◽  
Chenn Zhou

Abstract Steelmaking is an energy-intensive process. Thus, energy efficiency is highly important. Several stages of steelmaking involve combustion processes. One of the most energy-consuming processes in steelmaking is the slab reheating process in a reheat furnace (RF). The energy released by fuel combustion is used to heat steel slabs to their proper hot-rolling temperature. The steel slabs move through the reheat furnace passing the three stages of heating called: Preheating Zone (PZ), Heating Zone (HZ), and Soaking Zone (SZ) to finally leave the discharge door at a rolling temperature of 2375 °F. One way to improve a reheat furnace’s fuel consumption is by implementing oxygen-enriched combustion. This study investigates the implementation of oxygen-enriched combustion in a pusher-type reheat furnace. The increment of oxygen in the combustion process allows for increasing the furnace gas temperature. Consequently, the oxygen enrichment approach allows for the reduction of fuel injection. The principal goal of this investigation is to model the combustion-based on oxygen-enrichment and develop parametric studies of fuel injection rates. The different simulations aim to match the slab heat flux profile of the industrial reheat furnace pusher-type. Computational fluid dynamics are used to generate the slab heat flux distribution. To reach more uniform slab heating, oxygen and fuel ports were alternated. Also, injection angles were modified to optimize slab heating and avoid the impact of hot spots. Thermocouple readings of the industrial reheat furnace are compared to simulation results. The results determined that 40–45% fuel reduction can be achieved.

2020 ◽  
Vol 181 (2) ◽  
pp. 46-52
Author(s):  
Filip SZWAJCA ◽  
Krzysztof WISŁOCKI

Gas engines are a viable source of propulsion due to the ecological indicators of gas fuels and the large amount of the needed natural resources. Combustion of lean homogeneous gas mixtures allows achieving higher thermal efficiency values, which is a key factor in current engine development trends. Using the spark-jet ignition system (also called as Turbulent Jet Ignition or Two-stage combustion) significantly improves the efficiency and stability of the combustion process, especially in the part-load operation on lean or very lean mixtures. This paper presents the impact of using two different fuel injection methods: Port Fuel Injection or Mixer on the operation stability of a gas engine designed for LDVs. Comparative studies of two different mixture preparation systems were carried out on a single-cylinder AVL 5804 test engine. By re-cording the cylinder pressure for a significant number of engine cycles, it became possible to determine the repeatability of engine operation and to correlate the results with the mixture formation system and the air-fuel ratio. In the performed research the beneficial effect of the mixer system application on the engine operation stability in the part-load conditions was found.


Author(s):  
Reed Hanson ◽  
Andrew Ickes ◽  
Thomas Wallner

Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection (DI) of a higher reactivity fuel, otherwise known as reactivity controlled compression ignition (RCCI), has been shown as a method to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending to high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on a 13 l multicylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and DI of diesel fuel. Engine testing was conducted at an engine speed of 1200 rpm over a wide variety of loads and injection conditions. The impact on dual-fuel engine performance and emissions with respect to varying the fuel injection parameters is quantified within this study. The injection strategies used in the work were found to affect the combustion process in similar ways to both conventional diesel combustion (CDC) and RCCI combustion for phasing control and emissions performance. As the load is increased, the port fuel injection (PFI) quantity was reduced to keep peak cylinder pressure (PCP) and maximum pressure rise rate (MPRR) under the imposed limits. Overall, the peak load using the new injection strategy was shown to reach 22 bar brake mean effective pressure (BMEP) with a peak brake thermal efficiency (BTE) of 47.6%.


1998 ◽  
Vol 120 (4) ◽  
pp. 276-284 ◽  
Author(s):  
T. Ishii ◽  
C. Zhang ◽  
S. Sugiyama

The numerical simulations of reactive turbulent flows and heat transfer in an industrial slab reheat furnace in which the combustion air is highly preheated have been carried out. The influence of the ratio of the air and fuel injection velocities on the NOx production rate in the furnace has also been studied numerically. A moment closure method with the assumed β probability density function (PDF) for mixture fraction was used in the present work to model the turbulent non-premixed combustion process in the furnace. The combustion model was based on the assumption of instantaneous full chemical equilibrium. The turbulence was modeled by the standard k-ε model with a wall function. The numerical simulations have provided complete information on the flow, heat, and mass transfer in the furnace. The results also indicate that a low NOx emission and high heating efficiency can be achieved in the slab reheat furnace by using low NOx regenerative burners. It is found that the air/fuel injection velocity ratio has a strong influence on the NOx production rate in the furnace.


2019 ◽  
Vol 177 (2) ◽  
pp. 40-45
Author(s):  
Jerzy KOWALSKI

The paper presents a theoretical analysis of the impact of injection timing on the parameters of the combustion process and the com-position of exhaust gas from a 4-stroke engine designed to shipbuilding. The analysis was carried out based on a three-dimensional multi-zone model of the combustion process. This model has been prepared on the basis of properties of the research facility. The input data to the model were obtained through laboratory tests. Results of calculations showed that the change of the start of injection angle (SOI) from the value of 14 degrees before TDC to 22 degrees before TDC results in changes in the combustion rate and thus an increase in the temperature of the combustion process as well as the increase of nitric oxides fraction in the exhaust gas. Simultaneously the maximum combustion pressure increases also.


2018 ◽  
Vol 172 (1) ◽  
pp. 35-43
Author(s):  
Maciej SIDOROWICZ ◽  
Ireneusz PIELECHA

Direct fuel injection requires appropriate conditions for proper ignition of the formed mixture. The proper combustion process is shaped by the direct fuel injection, whose parameters vary. Preparation of the dose requires proper injector placement in the combustion chamber. This article focuses on the issue of the injector specific spatial and angular position in order to implement the injection and atomization of the fuel. The injectors pseudo-optimal location has been presented along with several changed positions. The research was conducted as a simulation experiment using AVL FIRE 2017 software. The best position of the injector was selected based on the fuel spraying and injection process indicators. It has been shown that the spatial position has the most impact and the injector placement angle is of secondary importance.


Author(s):  
Reed Hanson ◽  
Andrew Ickes ◽  
Thomas Wallner

Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection of a higher reactivity fuel, otherwise known as Reactivity Controlled Compression Ignition (RCCI), has been shown as a method to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending to high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on a 13L multi-cylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and direct injection of diesel fuel. Engine testing was conducted at an engine speed of 1200 RPM over a wide variety of loads and injection conditions. The impact on dual-fuel engine performance and emissions with respect to varying the fuel injection parameters is quantified within this study. The injection strategies used in the work were found to affect the combustion process in similar ways to both conventional diesel combustion and RCCI combustion for phasing control and emissions performance. As the load is increased, the port fuel injection quantity was reduced to keep peak cylinder pressure and maximum pressure rise rate under the imposed limits. Overall, the peak load using the new injection strategy was shown to reach 22 bar BMEP with a peak brake thermal efficiency of 47.6%.


2015 ◽  
Vol 36 (2) ◽  
pp. 225-238 ◽  
Author(s):  
Maciej Mikulski ◽  
Sławomir Wierzbicki ◽  
Andrzej Piętak

Abstract Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI) engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.


2020 ◽  
Vol 1 (6) ◽  
pp. 13-27
Author(s):  
Nguyen Thin Quynh ◽  
◽  
A.Y. Dunin ◽  

The paper presents the simulation result of the influence of the ratio of the diameter Dкс of the combustion chamber to its depth hкс and boost pressure рк on the characteristics of a 1ChN 12/13 single-cylinder engine with an injection pressure of 300 MPa at a crankshaft speed of 1400 min-1. The simulation was performed with Dкс/hкс from 3.4 to 10.0, and рк from 0.15 to 0.45 MPa. The re-sults show that the engine achieves the best performance when nitrogen oxides NOx in the exhaust gases decreases at Dкс/hкс= (7.8 ÷ 10), and the pressure рк from 0.25 to 0.35 MPa. At рк= 0.35 MPa, Dкс/hкс= 10, the indicated power increases by 7.1%. NOx reduces by 68% but soot, CO and CH in-crease by 4.5, 9.5, and 2.2 times, respectively. The results also show the impact of the boost pressure рк on spray characteristics. The boost pressure рк increases, the penetration, and the tip velocity decrease, but the spray angle changes a little. While the combustion chamber diameter changes, the penetration, and the spray angle change a little, and the tip velocity varies much. The boost pressure рк is a means of redistributing the amount of fuel burned in the jet and near the wall of the combus-tion chamber. With an increase in the boost pressure, the proportion of fuel that burns at the begin-ning of the combustion process under conditions of volumetric mixing increases, while at the end of the combustion process, a large concentration of fuel is located near the combustion chamber wall.


2020 ◽  
Vol 2 (1) ◽  
pp. 7-18
Author(s):  
Jerzy Merkisz ◽  
Maciej Bajerlein ◽  
Paweł Daszkiewicz ◽  
Patryk Urbański

The article contains an analysis of thermodynamic indicators of the CI engine with direct fuel injection. The tested unit was an engine with an unconventional crank-piston configuration, in which at a constant compression ratio, different engine crankshaft control variants were compared. In this article the time ranges in which the piston was located in the TDC were analyzed. Additionally, tests were carried out on a conventional unit for comparative purposes. For the purposes of the work, a piston displacement characteristic was generated in dynamic analysis in SolidWorks Motion. Then, this characteristic was used in the simulations of the combustion process in the AVL Fire program, where the most important thermodynamic indicators of the engine cycle were analyzed.


Sign in / Sign up

Export Citation Format

Share Document