Regularities pertinent to heat transfer in the gas layers of a torch in steam boiler fireboxes. Part III. Examples of heat transfer calculations in torch furnaces and steam boiler fireboxes

A procedure for calculating heat transfer in steam boiler fireboxes is developed proceeding from the scientific discovery of laws pertinent to radiation from torch gas layers. By using this procedure, it is possible to determine the distribution of heat flux densities both along the height and perimeter of all waterwall surfaces in a firebox and to calculate the maximal densities of incident heat fluxes. Examples of heat transfer calculation in a torch furnace and steam boiler firebox carried out using the procedure developed on the basis of the above-mentioned discovery are given. The calculation results are in satisfactory agreement with the results of heat transfer measurements in a torch furnace and steam boiler firebox. The difference between the calculated data and measurement results does not exceed 12%.     

Regularities of heat transfer in the gas layers of a steam boiler furnace flame. Part II. Gas layer radiation laws and the procedure for calculating heat transfer in furnaces,fire boxes,and combustion chambers developed on the basis of these laws

The article presents the results stemming from the scientific discovery of laws relating to radiation from the gas layers generated during flame combustion of fuel and when electric arc burns in electric-arc steel-melting furnaces. The procedure for calculating heat transfer in electric-arc and torch furnaces, fire-boxes, and combustion chambers elaborated on the basis of this discovery is described.     

燃煤锅炉中火焰黑度的在线检测与分析

在大型电站燃煤锅炉中，辐射是最主要的换热方式，研究煤粉燃烧火焰的黑度（辐射率）对炉内的辐射传热计算有着非常重要的作用。该文提出用彩色摄像机的RGB函数测量火焰黑度。当用彩色CCD摄像机摄取煤粉炉内火焰辐射图像时，实际上获得的是红、绿、蓝三基色波长下的单色辐射图像。基于Wien辐射定律和辐射图像处理技术可以从3幅单色辐射图像中检测到燃粉锅炉中火焰的黑度。该检测方法用黑体炉进行标定。在3种负荷工况下，对两台燃煤锅炉的检测结果表明：沿炉膛高度方向，燃烧器区域的火焰黑度最大，炉膛上部的火焰黑度较小；灰份含量较高的煤，其燃烧火焰黑度较大；当负荷变大时，火焰黑度也随之增加。     

A Procedure for Calculating the Total Heat Transfer in Chamber Furnaces

An analysis and results from investigations into the effect of the power output, layout, and operating conditions of burners on the total heat transfer in the furnaces of power-generating boilers are presented. A calculation procedure that takes these factors into account is proposed, and conclusions regarding the lines of research for improving the procedure are formulated.     

Calculation of heat transfer in boiler furnaces during firing of fuel in a bed

A method for calculating complex heat transfer in furnaces is proposed, central to which is using the experimentally determined temperature of the bed of burning solid fuel.     

Procedure of calculating liquid flowrates in wall film and heat transfer crisis in tubes

A brief review of investigations into liquid distribution between the flow core and wall film in tubes previously carried out is given. The relationship between mass transfer processes and heat transfer crisis is shown. The procedure of calculating heat transfer crisis in tubes with uniform heat input along the length based on experimental data from the databank of the Physics and Power Engineering Institute (FEI) is presented.     

Anode attachment and received heat of argon torch plasma with high lateral airflow as function of current

The torch plasma arc has useful characteristics of high energy and high current. The mode of torch plasma arcs can be flexible, even if the arc is exposed to the lateral gas. In this paper, we measured the input power, heat power, and heat efficiency of the torch plasma arc to the anode in order to determine the current effect on the anode attachment of plasma torch arc with high lateral air velocity, varying from 0 to 80 m/s at a plasma Ar flow rate of 12 slm. As a result, the input power increases with lateral gas velocity such as from about 8000 W to 16,000 W and the heat efficiency decreases with the lateral gas velocity such as from about 50% to 25% at the current I=150 A and appearance plasma length L_a=1 cm. These results could be applied to providing the electrical power from the ground to high‐speed mobiles, v.v., and to reducing an anode surface erosion by the anode spot movement. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(2): 29–35, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20479     

循环流化床锅炉炉膛内辐射换热计算方法探讨

对比了两种循环流化床（ＣＦＢ）锅炉炉膛内求取辐射换热系数的方法；计算表明：炉内稀相区辐射换热系数占总传热系数的６５％左右．     

半透明介质内辐射与导热复合换热过程熵产分析

本文用数值模拟方法对一维半透明介质内辐射与导热复合换热过程进行了热力学分析，给出了参与性介质中辐射与导热复合换热过程的无因次熵产公式和熵产数公式，分析了辐射—导热参数、光学厚度、散射反照率、壁面黑度对熵产数的影响。结果表明，在整个系统中，熵产数满足热力学第二定律，从而证明了无因次熵产公式及熵产数公式的正确性。最后从熵产数的角度分析了系统中的功损。     

基于图像处理及辐射传热逆问题求解的二维炉膛温度场重建

基于辐射图像处理和辐射传热逆问题求解,建立一种二维炉膛温度场重建方法。该方法中,图像采集装置（如ＣＣＤ摄像机）成像单元接收的辐射能由炉膛中各气体和壁面单元发射的辐射能决定。采用Ｍｏｎｔｅ Ｃａｒｌｏ方法计算出ＣＣＤ摄像机各成像单元所接收的各气体和壁面单元的辐射能的份额,即炉膛温度可从ＣＣＤ摄像机成像单元接收辐射能中重建温度分布。研究对象为一个由灰色炉膛壁面和灰色气体所组成的二维辐射－吸收系统。在Ｃ     

Industrial applications of heat transfer enhancement: The modern state of the problem (a Review)

Methods used for enhancing heat transfer in power installations and industrial thermal engineering apparatuses are reviewed. Classification of these methods is given, and the corresponding types of intensifiers are considered.     

Fuel Cell Based Power-Generating Installations: State of the Art and Future Prospects

Specific features of power-generating installations constructed using different types of fuel cells are considered. Problems and trends of their development in Russia and abroad are analyzed. Fuel cell commercialization lines, their application niches, and the most well-known projects of constructing and exploiting fuel cell-based power-generating installations are described. Special attention is paid to analyzing the specific features pertinent to the domestic market of fuel cells and prospects of different lines of their application taking into account competition from other energy sources. Conclusions about the most topical development lines of the considered technologies under the conditions of Russia are drawn with due regard to the available groundwork as well as technical and economic aspects. It is pointed out that the main application field of fuel cells in Russia may be distributed generation of electricity, including off-grid supply of power to consumers on the basis of network and liquefied natural gas, liquefied hydrocarbon gases, and also renewable energy sources. In this regard, installations involving combined generation of electricity and heat, including small ones with a capacity of a few tens or hundreds of kilowatts, are of special interest. Prospective market niches for using fuel cells may include pipeline cathodic protection stations, utilization of biogas obtained, e.g., in reprocessing domestic waste, emergency and uninterruptible power supply systems, propulsion power installations of air drones, auxiliary power installations with a capacity of 1–3 kW, and utilization of hydrogen rejected from chemical production facilities. In view of existing groundwork and cooperation, concentration of efforts aimed at developing solid oxide, solid polymeric, and alkaline fuel cells in Russia seems to be the most topical issue. The use of molten carbonate fuel cells may be of considerable practical interest for reclaiming landfill gas at solid domestic waste landfills and at aeration fields, a problem that is an issue for many cities in the country; such cells can also be used for concentrating and extracting CO₂ from fuel gases.     

Applicability of the standard method for calculating heat transfer in furnaces with stokers

Features pertinent toheat transfer in furnaces during combustion of solid fuel in a bed are considered. The results from the tests are compared with the calculated characteristics of heat transfer. A conclusion is drawn regarding the need to revise the calculation method for furnaces with a bed of burning fuel.     

Accounting for the Effect of Noncondensing Gases on Interphasic Heat and Mass Transfer in the Two-Fluid Model Used in the KORSAR Code

A model is presented of the interphasic heat and mass transfer in the presence of noncondensable gases for the KORSAR/GP design code. This code was developed by FGUP NITI and the special design bureau OKB Gidropress. It was certified by Rostekhnadzor in 2009 for numerical substantiation of the safety of reactor installations with VVER reactors. The model is based on the assumption that there are three types of interphasic heat and mass transfer of the vapor component: vapor condensation or evaporation on the interphase under any thermodynamic conditions of the phases, pool boiling of the liquid superheated above the saturation temperature at the total pressure, and spontaneous condensation in the volume of gas phase supercooled below the saturation temperature at the vapor partial pressure. Condensation and evaporation on the interphase continuously occur in a two-phase flow and control the time response of the interphase heat and mass transfer. Boiling and spontaneous condensation take place only at the metastable condition of the phases and run at a quite high speed. The procedure used for calculating condensation and evaporation on the interphase accounts for the combined diffusion and thermal resistance of mass transfer in all regimes of the two-phase flow. The proposed approach accounts for, in a natural manner, a decrease in the rate of steam condensation (or generation) in the presence of noncondensing components in the gas phase due to a decrease (or increase) in the interphase temperature relative to the saturation temperature at the vapor partial pressure. The model of the interphase heat transfer also accounts for the processes of dissolution or release of noncondensing components in or from the liquid. The gas concentration at the interphase and on the saturation curve is calculated by the Henry law. The mass transfer coefficient in gas dissolution is based on the heat and mass transfer analogy. Results are presented of the verification of the interphase heat and mass transfer used in the KORSAR/GP code based on the data on film condensation of steam-air flows in vertical pipes. The proposed model was also tested by solving a problem of nitrogen release from a supersaturated water solution.     

Some results of the verification of SERPENT code while calculating heat transfer crisis in uniformly heated tubes

The results of calculating the parameters of heat transfer crisis regimes in uniformly heated tubes, obtained with the aid of look-up tables (LTs) Grnv-95 and FEI-91 are presented.     

Mathematical simulation of the furnace and turning gas conduit of a P-50R boiler during joint combustion of solid and gaseous fuel

Results obtained from a detailed analysis of aerodynamics, combustion, heat transfer, and formation of nitrogen oxides in the furnace and turning gas conduit of a boiler during three-stage joint combustion of solid and gaseous fuel are presented. The analysis was carried out by numerically calculating spatial flows, heat-and-mass transfer, and chemical reactions in power installations.     

Development of a system for monitoring the temperature of the waterwalls of a TGM-96 boiler

Different methods for monitoring the temperature of tubes in the furnaces of power-generating boilers are considered. The main characteristics of a new system for monitoring the temperature of the waterwalls of TGM-96 boilers at the OAO Mosenergo TETs-23 Cogeneration Station are presented along with the results from its development and partial introduction.     

Studying the process through which gas is generated in independent power installations

Results from experimental studies of the gas generation process as applied to independent power-generating installations are presented. Circuit solutions for implementing this technology are presented, and recommendations for putting these installations into operation aimed at expanding the use of low-grade kinds of fuel for power generation purposes are given.     

Study of pressure drop and heat transfer in a swirl flow with one-sided heating in a range of heat flowrates below boiling crisis

A representative mass of experimental data on pressure drop and heat transfer under forced convection and boiling in a swirl water flow under one-sided heating conditions is obtained. Recommendations are given for calculating pressure drop in a swirl flow. A method of calculating heat transfer in channels with onesided heating is proposed.