Diffusion Combustion of Liquid Heptane in a Small Tube with and without Heat Recirculating

Li, Junwei; Huang, Jinghuai; Zhao, Dan; Zhao, Jianxun; Yan, Mi; Wang, Ningfei

doi:10.1080/00102202.2012.690673

Cited by 15 publications

(5 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Junwei et al [59] studied the diffusion flame characteristics of n-heptane fuel in a small quartz tube with an ID of 4 mm and OD of 6 mm. The study investigated the effect of heat recirculating, the schematic of the setup is shown in Figure 49.…”

Section: Combustionmentioning

confidence: 99%

Towards the Development of Miniature Scale Liquid Fuel Combustors for Power Generation Application—A Review

Sankar,

Sudarsanan,

Mukhopadhyay

et al. 2023

Energies

View full text Add to dashboard Cite

As the demand for powerful, light energy sources continues to grow, traditional electrochemical batteries are no longer sufficient and combustion-based power generation devices have become an attractive alternative due to their high energy density, compact size, fast recharging time and long service life. While most research on miniature-scale combustors has focused on gaseous fuels, the use of commonly available liquid fuels has the potential to be highly portable and economical. However, the complexity of droplet atomization, evaporation, mixing and burning in a limited volume and short residence time has presented significant challenges for researchers. This review focuses on various methodologies proposed by researchers (like flow burring injector, fuel film injection, injecting into porous media, electrospray and some self-aspirating designs) to overcome these challenges, the combustion behaviour and different instabilities associated with liquid fuels at small scales. The current review intends to present a clear direction to channel the efforts made by researchers to overcome the difficulties associated with liquid fuel combustion at small scales for power generation applications. Additionally, this review aims to give an overview of power systems at the micro and meso scales that operate using liquid fuels. The methodologies introduced like electrospray requires external power, which again makes the system complex. Towards the development of standalone type power generators, the self-aspirating design which makes use of hydrostatic pressure, fuel film injection or taking advantage of exhaust gas enthalpy to preheat and evaporate the liquid fuel are the promising methodologies.

show abstract

Section: Combustionmentioning

confidence: 99%

Towards the Development of Miniature Scale Liquid Fuel Combustors for Power Generation Application—A Review

Sankar,

Sudarsanan,

Mukhopadhyay

et al. 2023

Energies

View full text Add to dashboard Cite

show abstract

“…It is noted that the simulations in this work were conducted using the commercial CFD tool ANSYS Fluent [16], where the authors took the thermal diffusion effects into account. To further understand the importance of conjugate heat transfer for the inlet mixture and the negative role of the external heat losses, Li et al investigated the diffusion combustion of liquid heptane in a small tube with and without heat recirculation via both experimental and numerical approaches [17]. They demonstrated that it was possible to reach a stable flame even without heat recirculation.…”

Section: Numerical Studies Of Micro-diffusion Flamesmentioning

confidence: 99%

“…Experimental and numerical study of diffusion combustion in a micro channel using liquid n-heptane and air mixture, with and without heat recirculation, by Li et al[17].Top: Photos of flame at different Reynolds numbers (b); Bottom: Temperature contours for various heat loss coefficients: (h Unit: W/m 2 − K): (a) h = 0, (b) h = 1, (c) h = 10, (d) h = 20, (e) h = 50, (f) h = 75, (g) h = 100.…”

mentioning

confidence: 99%

Numerical Investigations of Micro-Scale Diffusion Combustion: A Brief Review

2019

View full text Add to dashboard Cite

With the increasing global concerns about the impacts of byproducts from the combustion of fossil fuels, researchers have made significant progress in seeking alternative fuels that have cleaner combustion characteristics. Such fuels are most suitable for addressing the increasing demands on combustion-based micro power generation systems due to their prominently higher energy density as compared to other energy resources such as batteries. This cultivates a great opportunity to develop portable power devices, which can be utilized in unmanned aerial vehicles (UAVs), micro satellite thrusters or micro chemical reactors and sensors. However, combustion at small scales—whether premixed or non-premixed (diffusion)—has its own challenges as the interplay of various physical phenomena needs to be understood comprehensively. This paper reviews the scientific progress that researchers have made over the past couple of decades for the numerical investigations of diffusion flames at micro scales. Specifically, the objective of this review is to provide insights on different numerical approaches in analyzing diffusion combustion at micro scales, where the importance of operating conditions, critical parameters and the conjugate heat transfer/heat re-circulation have been extensively analyzed. Comparing simulation results with experimental data, numerical approaches have been shown to perform differently in different conditions and careful consideration should be given to the selection of the numerical models depending on the specifics of the cases that are being modeled. Varying different parameters such as fuel type and mixture, inlet velocity, wall conductivity, and so forth, researchers have shown that at micro scales, diffusion combustion characteristics and flame dynamics are critically sensitive to the operating conditions, that is, it is possible to alter the flammability limits, control the flame stability/instability or change other flame characteristics such as flame shape and height, flame temperature, and so forth.

show abstract

“…The experimental results are promising. And the energy harvesting techniques have potential to be applied on a thermoacoustic system with diffusion flames [37,38].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Feedback Control of Thermoacoustic Oscillations Using Least Mean Square-Based Algorithms

Zhang

Guan

2015

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

Thermoacoustic instabilities are characterized by self-sustained largeamplitude pressure oscillations, which are produced by the interaction between unsteady heat release and acoustic waves. Such instabilities are detrimental to land-based gas turbine and aero-engines. To mitigate thermoacoustic instabilities, the coupling between unsteady heat release and pressure perturbations must somehow be interrupted. Feedback control techniques with a dynamic controller implemented can be used to achieve this. One of the most classical controllers is based on a finite-or infinite-impulse response filter, whose coefficients are optimized using least mean square algorithm (LMS). In this work we experimentally investigated and compared the performance of four LMS-based algorithms on stabilizing an unstable thermoacoustic system. Effects of the step size and filter length are studied one at a time. It is found that the filter length plays an important role in determining the convergence speed and steady error. In addition, the step size involved in the LMS algorithms is shown to be varied over a wide range. However, when the step size is small, simplified/revised LMS-based algorithms perform better than the conventional one in the absence of a feedback term. However, with the step size increased, these algorithms behave similarly. In order to improve the performance of conventional LMS-based algorithms, a time-varying step-size controller is developed and experimentally implemented. Approximately 50 dB sound reduction is achieved. The controller is also demonstrated to be able to track and prevent the onset of new limit cycle resulting from the changes of fuel flow rate. Finally, the transfer function of the thermoacoustic system is measured by injecting broad-band white noise.

show abstract

Diffusion Combustion of Liquid Heptane in a Small Tube with and without Heat Recirculating

Cited by 15 publications

References 25 publications

Towards the Development of Miniature Scale Liquid Fuel Combustors for Power Generation Application—A Review

Towards the Development of Miniature Scale Liquid Fuel Combustors for Power Generation Application—A Review

Numerical Investigations of Micro-Scale Diffusion Combustion: A Brief Review

Experimental Investigation of Feedback Control of Thermoacoustic Oscillations Using Least Mean Square-Based Algorithms

Contact Info

Product

Resources

About