Kerosene Temperature Research Articles

Effects of liquid-fuel temperature on rotating-detonation-wave propagation

The utilization of liquid fuel will greatly expand the application scope of rotating detonation engines, and there are still great challenges to achieve high-performance liquid-fuel rotating detonation operation. In this paper, aviation kerosene was used as the liquid fuel to investigate the effects of fuel temperature on the propagation characteristics of rotating detonation waves in two combustor structures: annular and cavity. An electric heating tape was employed to heat the kerosene up to 390 K. The results demonstrate that increasing the temperature of kerosene enhances its atomization efficiency, leading to a marked enhancement in the peak pressure and propagation stability of detonation waves. Moreover, the duration required to establish a detonation wave is notably reduced, as low as 11.2 ms. Furthermore, the detonation wave velocity increases with fuel temperature, with significantly higher velocities observed in the cavity combustor structure compared to the annular combustor structure. In the cavity combustor, the detonation wave velocity can reach up to 74 % of the theoretical CJ value. The results verify the feasibility of improving the rotating-detonation performance via increasing liquid-fuel temperature, which can provide reference for the engineering application of rotating detonation.

Simulation of flow and heat transfer characteristics of laminated turbine blades with kerosene cooling channels

An air-kerosene thermal mass coupled turbine blade with kerosene micro-channels added to the traditional laminated structure turbine blade is proposed, and numerical simulations are carried out. The enhanced heat transfer mechanism of the air-kerosene thermal mass coupled turbine blade is studied, and the influence of different kerosene temperatures, blowing ratios, and solid thermal conductivity on the heat transfer of the laminated turbine blades is analyzed. The results show that adding kerosene micro-channels can significantly reduce the blade temperature and change the cooling gas heat transfer direction inside the laminate cooling structure. Compared with the traditional laminate cooling structure, adding kerosene micro-channels can significantly improve the heat transfer performance of the blades, and the integrated cooling efficiency increases by 31.7%. Moreover, when the kerosene temperature decreases from 400-300 K, the cooling efficiency increases by 3.9%. Similar conclusions can be obtained by studying the increases in the blowing ratio and the solid thermal conductivity, respectively.

Effect of fuel temperature on mixing characteristics of a kerosene jet injected into a cavity-based supersonic combustor

To explain the phenomenon observed in previous experiments of kerosene-ignition failure in scramjet combustors as the kerosene temperature increases, we numerically investigate the mixing characteristics of a kerosene jet injected into a cavity-based supersonic combustor at different injection temperatures by using a compressible two-phase flow large-eddy simulation based on the Eulerian–Lagrangian approach. The results indicate that, upon injecting kerosene at high temperatures, the flow field preceding the leading edge of the cavity is similar to a typical gas jet in supersonic crossflow. The wall counter-rotating vortex pair (CVP) develops more fully and eventually becomes the main vortex pair. This evolution of the wall CVP modifies the cavity shear layer and alters the local flow-field characteristics near the cavity. Upon injecting kerosene at high temperatures, its evaporation rate increases sharply and the cavity recirculation zone enlarges, which causes more kerosene vapor to be entrained into the cavity. Because the kerosene-vapor temperature is lower than that of the low-speed fluid in the cavity, a significant amount of kerosene vapor entering the cavity not only makes the mass fraction of kerosene in the cavity exceed the fuel stoichiometric mass fraction but also reduces the temperature in the cavity, which negatively impacts the ignition process. The ignition delay time is much longer when the injection temperature is high, which is consistent with the inability of the initial flame kernel to form in the experiment.

Experimental study on ignition and lean blowout characteristics of high temperature rise combustor

Ignition and lean blowout characteristics are an important performance index of the Aeroengine combustor, which is directly related to the reliability of the whole engine. The ignition process of the combustor was filmed by a CCD camera, and three stages of successful ignition were obtained. By changing the intake conditions, the variation of the minimum ignition energy in the fuel-air ratio (FAR) is tested. With the decrease of the FAR, the minimum ignition energy increases and there is a sudden increase process. As the room temperature and pressure conditions, the lean blowout (LBO) FAR is roughly 0.014, and Increasing kerosene temperature can improve the LBO performance in the combustor.

Numerical study on atomization and evaporation characteristics of preheated kerosene jet in a rotating detonation scramjet combustor

Preheated kerosene injection is one of the fuel supply methods for a rotating detonation scramjet engine. The injection and evaporation of preheated kerosene were numerically investigated in an expansion configuration combustor with intake air at a speed of Mach 2 at various fuel temperatures for the first time. The Euler-Lagrangian method was used to describe the gas–liquid two-phase flow phenomenon. The random trajectory model was used to track the droplet movement process, and the infinite thermal conductivity model was used to describe the evaporation process. The numerical analysis of preheated kerosene injection atomization in supersonic inflow under constant liquid–gas momentum flux ratio was performed. The results reveal that the penetration depth of various thermal jets in the combustor changes slightly with a constant liquid–gas momentum flux ratio, independently of the kerosene temperature and liquid–gas coupling influence in the mainstream zone. The shape of the outer edge of the liquid mist evidently varies in a disordered manner. Using preheated kerosene as the fuel of the rotating detonation scramjet can increase the mixing degree of gas–liquid two-phase jets and accelerate the evaporation of droplets. Moreover, the fragmentation and atomization effects of thermal kerosene droplets are significantly improved. The analysis demonstrates that preheated kerosene injection may be beneficial to ignition and contributes to the self-sustainment of the detonation waves in the engine.

Measurement of airblast atomization of low temperature kerosene with 25 kHz digital holography

Atomization of low temperature fuel is of great importance in a jet engine combustor, and its visualization and diagnostics are challenging, especially in the presence of shreds and ligaments. A 25 kHz picosecond pulsed digital inline holography system is applied to measure the spray produced by an airblast atomizer with low temperature kerosene. The breakup process of shreds and ligaments of -37∘C kerosene are visualized and analyzed, revealing the transition of liquid jet disintegrating into droplets under the atomizing air film. Three-dimensional positions and size distributions of droplets in spray are acquired. It is found that a decrease in the kerosene temperature increases shreds and ligaments in the spray, which eventually leads to reduction of droplet density and increase of droplet size, while increasing the air pressure can compensate the degradation. This work also demonstrates that high speed holographic imaging is a powerful tool in spray diagnostics and liquid breakup visualization.

Numerical Study on Regenerative Cooling Characteristics of Kerosene Scramjets

The use of kerosene-based regenerative cooling for scramjet has been found widespread attention due to its inherent nature of high energy utilization efficiency and good thermal protection performance. In order to provide a reference for the later design and experiments, three-dimensional turbulence simulations and sensitivity analysis were performed to determine the effects of three operating mode parameters, heat flux, mass flow rate, and outlet pressure, on the regenerative cooling characteristics of kerosene scramjets. A single rectangular-shaped channel for regenerative cooling was assumed. The RNG k-ε turbulence model and kerosene cracking mechanism with single-step global reaction were applied for the supercritical-pressure heat transfer of kerosene flows in the channel. Conclusions can be drawn that as the kerosene temperature rises along the channel, the decrease of fluid density and viscosity contributes to increasing the fluid velocity and heat transfer. When the kerosene temperature is close to the pseudocritical temperature, the pyrolysis reaction results into the rapid increase of fluid velocity. However, the heat transfer deterioration occurs as the specific heat and thermal conductivity experience their turning points. The higher heat flux leads to lower heat transfer coefficient, and the latter stops rising when the wall temperature reaches the pseudocritical temperature. The same rising trend of the heat transfer coefficient is observed under different outlet pressures, but the heat transfer deterioration occurs earlier at smaller outlet pressure for the reason that the corresponding pseudocritical temperature decreases. The heat transfer coefficient increases significantly along with the rise of the mass flow rate, which is mainly attributable to the increase of Reynolds number. Quantitative results indicate that as the main influence factors, the heat flux and mass flow rate are respectively negatively and positively relative to the intensification of heat transfer, but outlet pressure always has little effects on cooling performance.

Analysis of Influence of Structural Parameters of Regenerative Cooling Channel of Scramjet

In this paper, a three-dimensional modeling analysis of regenerative cooling channels of scramjet engines is carried out, and the cooling channel structure parameters such as inner wall thickness, fin thickness, channel aspect ratio, cross-sectional area and number of channels are used to cool the regenerative cooling. The conclusion is as follows: the thinner inner wall thickness corresponds to a lower wall temperature, while the heat flux density is larger, and the kerosene temperature and pressure change little; the thin fins correspond to the higher wall temperature and oil temperature, but the kerosene is in the cooling channel. The pressure loss is smaller, and the thicker fins have a lower maximum wall temperature and maximum oil temperature, but a larger pressure loss; the greater the aspect ratio, the better the cooling effect of the channel, and the wall temperature and oil temperature are relatively low, but also It is not possible to choose a cooling channel with an aspect ratio that is too large. This is because after the aspect ratio is greater than 1, the pressure loss in the channel increases as the aspect ratio increases; reducing the channel cross-sectional area can increase the flow rate, thereby increasing convection The heat transfer coefficient makes the maximum wall temperature and oil temperature lower, but the kerosene with a too small channel area has a larger flow resistance in the channel, and the effective heat exchange area also becomes smaller; an increase in the number of channels can make the transfer Heat is strengthened, and cooling channels can be arranged more when the temperature of the material permits to give full play to the kerosene heat sink and fin effect to enhance the cooling effect.

Multivariable control of regeneratively-cooled scramjet engine with two-stage kerosene injection based on H∞ method

Aimed at diversity of hypersonic flight mission, this paper discusses the multivariable control of regeneratively-cooled scramjet engine with two-stage kerosene injection for both safety operation and high performance. Firstly, the multivariable control strategy is proposed to solve the inlet unstart and overtemperature control issues. There are two linear models identified for different control objects because of the control strategy. Among them, the inputs are two-stage fuel equivalence ratios, and the outputs are thrust, inlet steady margin, and thrust and kerosene temperature at cooling channels outlet, respectively. Secondly, H∞ multivariable control method is introduced. The standard H∞ control problem with structural uncertainty is constructed in detail. In order to settle the issue that the control strategy selects various controlled output variables under different flight missions, a switching controller based on controller output reset is proposed. Lastly, not only thrust and steady margin control loop, but also thrust and fuel temperature control loop of the regeneratively-cooled scramjet engine are established. Simultaneously, the switching system with the two control loops is designed in this paper. Simulation results indicate that rapid responses of control system, smooth and steady switching between different loops are realized. The engine with control system can operate steadily with high performance at both specific and variable operating conditions.

Multi-objective coordinated control of regeneratively-cooled scramjet engine with two-stage kerosene injection

Aimed at diversity of hypersonic flight mission, multi-objective coordinated control of regeneratively-cooled scramjet engine with two-stage kerosene injection is discussed for guaranteeing a safe, steady and high-efficient operation. Firstly, characteristics analyses and system identification are conducted under the situation of flight Mach number 5 using unsteady 1-D model for regeneratively-cooled scramjet engine. Based on transfer functions obtained from system identification, corresponding proportional integral (PI) controllers are designed for different control objectives such as thrust, steady margin and kerosene temperature at cooling channels outlet. Secondly, different control strategies where flow rates of two stage kerosene injections are adjusted are created in different single control loops, including thrust regulation, steady margin protection, restart recovery, temperature protection and overtemperature recovery control loop. Optimal control strategy is determined ultimately in respective single control loop by analyzing merits and demerits from the perspectives of response speed and engine performance. Lastly, multi-loop coordinated control system is designed on the basis of switch rules and algorithm. Simulation results indicate that rapid responses of control system, smooth and steady switch between different loops are realized. Engine can operate steadily with high performance and recover to a safe operation state rapidly during unstart and overtemperature.

Numerical study of heat transfer deterioration of turbulent supercritical kerosene flow in heated circular tube

Turbulent flow and convective heat transfer of supercritical kerosene flow in an axisymmetrically heated circular tube with a diameter of 2mm and at a mass flow rate range of 0.0015–0.015kg/s and a wall heat flux range of 0.15–2.0MW/m2 are numerically studied using Reynolds averaged Navier–Stokes method with a two-layer turbulence model. The thermophysical and transport properties of kerosene are determined by a 10-species surrogate with the Extended Corresponding State method. Mesh dependency is first investigated and numerical results of fuel and wall temperatures are compared with experimental data for validations. The results show that flow properties such as velocity and Reynolds number increase significantly along the axial direction as the fuel temperature rises and kerosene undergoes the state transition from liquid to supercritical state. Deterioration of convective heat transfer is found to occur when the wall heat flux exceeds a critical value and at the same time, the wall temperature approaches the pseudo-critical temperature of kerosene. The present results show that deterioration of heat transfer are attributed to the development of turbulent properties in the near-wall region based on the results of turbulent kinetic energy and turbulence production term. The relation between the critical heat flux (qwc) for occurrence of heat transfer deterioration and the mass flux (G) is studied and a fitting formula of qwc and G is obtained.

Feasibility assessment of refinery waste heat-to-power conversion using an organic Rankine cycle

Industrial waste heat is a large potential resource for generation of carbon-free electricity. This study investigates the technical and economic feasibility of converting waste heat from a stream of liquid kerosene which must be cooled down to control the vacuum distillation temperature. The process conditions were determined for a simple 250kW organic Rankine cycle (ORC) with a heat extraction loop. The pinch point technique was adopted to determine the optimum evaporation and condensation temperatures and assess the influence of the kerosene temperature at the evaporator exit on net power output. The operating conditions and performance of the ORC system were evaluated with eight potential refrigerants and refrigerant mixtures such as R123, R134a, R245fa, isobutane, butane, pentane, an equimolar mixture of butane and pentane, and a mixture of 40% isobutane and 50% butane on a mole basis. A financial model was established for the total plant cost. Results show that isobutane, of the pure fluids, yields the best plant efficiency of 6.8% with approximately half of the kerosene flow available, and the efficiency can be increased up to 7.6% using the butane/pentane mixture. The optimum kerosene temperature at the evaporator outlet is estimated to be 70°C for all the fluid, except the butane/pentane mixture, which meets the design constraint not to disturb the existing distillation process. A capital cost target of $3000/kW could be achieved with a payback period of 6.8years and the internal rate of return (IRR) of 21.8%. Therefore, if the detailed engineering, component fabrication and construction can be achieved within the cost target, the installation of a 250kW ORC waste heat power converter on the kerosene cooling line would be technically feasible and economically viable.

A Parametric Experimental Study on the Heat Transfer Characteristics of Supercritical Kerosene in Active Cooling Channels of Scramjets

Heat transfer characteristics of China RP-3 kerosene under supercritical state were experimentally investigated. Results showed that at sub-critical pressures, heat transfer deterioration happens, and the wall temperature rises from approximately 350°C to 750°C. This is thought to be resulted from film boiling when kerosene begins to transfer from liquid to gas. At supercritical pressures, heat transfer enhancement was observed. And it is mainly caused by the sharp increase of specific heat of kerosene when the wall temperature is approaching the critical temperature of kerosene. The heat transfer coefficient doesnt increase with velocity for kerosene, because the thermal properties and residence time of kerosene have changed when velocity is changed.

Experimental Investigation on Coking Characteristics of China RP-3 Kerosene under High Temperature and Long-Duration Conditions

Coking characteristics of China RP-3 under high temperature (above 650°C) and long-duration (20 minutes) conditions, especially the effects of temperature, pressure, and inner diameter of cooling channels on coking amount were experimentally investigated. Temperature of kerosene in experiments varied from 650°C to 730°C, pressure varied from 1.8MPa to 3.5MPa, and the mass flow rate was approximately 120g/min. Results showed that temperature has a significant influence on coking amount. Even a small increment of temperature induces remarkable coke formation. However, pressure and inner diameter of the tube has a relatively little effect on it. The coking amount increases as pressure and inner diameter increase, but the increasing rate is decreasing. It is considered that inner diameter mainly affects residence time. When residence time increases to some extent, coking amount begins to grow slowly even stop increasing. This is resulted from two reasons. Firstly, the cracking conversion percentage reaches an upper limit when residence time is adequately long; secondly, coke gradually covers the inner wall of the tube, leading to isolation of kerosene from the metal surface to form coking.

Numerical investigation on flow and convective heat transfer of aviation kerosene at supercritical conditions

avier-Stokes equations were solved using RNG k-epsilon turbulence model with low Reynolds number correction. The thermophysical and transport properties of the China RP-3 kerosene were calculated with a 10-species surrogate and the extended corresponding state method (ECS) combined with Benedict-Webb-Rubin equation. The independence of grids was first studied and the numerical results were then compared with experimental data for validation. Under flow conditions given in the paper, the results show that deterioration of convective heat transfer occurs when the wall temperature is slightly higher than the pseudo-critical temperature of kerosene for cases with wall heat flux of 1.2 and 0.8 MW/m(2). The degree of the heat transfer deterioration is weakened as the heat flux decreases. The deterioration, however, does not happen when the heat flux on the pipe wall is reduced to 0.5 MW/m(2). Based on the analysis of the near-wall turbulent properties, it is found that the heat transfer deterioration and then the enhancement are attributed partly to the change in the turbulent kinetic energy in the vicinity of pipe wall. The conventional heat transfer relations such as Sieder-Tate and Gnielinski formulas can be used for the estimation of kerosene heat convection under subcritical conditions, but they are not capable of predicting the phenomenon of heat transfer deterioration. The modified Bae-Kim formula can describe the heat transfer deterioration. In addition, the frictional drag would increase dramatically when the fuel transforms to the supercritical state.

Performance of a tubular solid oxide fuel cell with model kerosene reformate gas

A performance of an anode-supported tubular Ni–8YSZ/Ni–ScSZ/ScSZ/GDC/LSC cell was investigated at 650–750 °C by feeding model kerosene reformate gas (H 2, H 2O, CO, CO 2, and CH 4) to a Ni–8YSZ/Ni–ScSZ anode. Variations of gas composition were observed not only between inlet and outlet of anode to estimate the degree of internal reforming, but also during current input by online quadrupole mass spectrometry and Fourier-transform infrared spectrometry. The electrochemical performance of the cell was independent of reforming temperature of kerosene, i.e. gas composition (in particular CH 4 concentration) at moderate anode gas flow rates. At open-circuit states, 10% or less methane in the kerosene-reformed gas was readily converted by steam or CO 2 over the Ni–8YSZ/Ni–ScSZ electrode so that gas compositions could almost follow the thermodynamic equilibrium at 650–750 °C. This suggests that the internal reforming should proceed almost completely over the Ni anode. Consumption of H 2 and CO and production of CO 2 were observed during current input. I–V characteristics remained constant at 650 °C as long as anodic W/F was more than 0.2 kg mmol − 1 s. It was demonstrated that a catalytic activity of an anode electrode for hydrocarbons will be important for SOFCs with liquid fuels such as kerosene in order not to deteriorate cell performance.

Solar Extraction of Tar from Tar Sand Using Hot Kerosene

Utilization of solar energy for the heating of kerosene to be used in the extraction of tar from tar sand was theoretically and experimentally investigated. The idea is to replace the working fluid of a conventional flat-plate collector with kerosene instead of water. Hot kerosene is stored in a tank at a temperature of 50–75°C after, which it flows through an extractor filled with tar sand. Thermal performance of collector was found and compared with that of a similar collector with water as a working fluid. Preliminary extractor performance was also found in terms of percentage of recovery versus kerosene temperature. It was found that the efficiency of the collector using water was reduced by 15% when the working fluid was replaced with kerosene, and this was in fair agreement with the theoretical prediction. It was also found that, for the tar sand sample used, the percentage of recovery approaches 30% as the extraction temperature was increased to 70°C. Further increase in extraction temperature had a negligible effect on recovery.

The Relation between the Temperature of Kerosene and the Explosion Pressure of the Supernatant Mixture of Air and Vapor.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Relation between the Temperature of Kerosene and the Explosion Pressure of the Supernatant Mixture of Air and Vapor.W. P. Bradley and C. F. HaleCite this: Ind. Eng. Chem. 1909, 1, 6, 345–351Publication Date (Print):June 1, 1909Publication History Published online1 May 2002Published inissue 1 June 1909https://doi.org/10.1021/ie50006a006RIGHTS & PERMISSIONSArticle Views45Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (678 KB) Get e-Alerts