Optimization Study of Active-Passive Heating System Parameters in Village Houses in the Southern Xinjiang Province

Aiming at the problems of large energy consumption and serious pollution of winter heating existing in the rural buildings in Southern Xinjiang,a combined active-passive heating system was proposed,and the simulation software was used to optimize the parameters of the system,according to the parameters obtained from the optimization,a test platform was built and winter heating test was carried out.The simulation results showed that the thickness of the air layer of 75 mm,the total area of the vent holes of 0.24 m^(2),and the thickness of the insulation layer of 120 mm were the optimal construction for the passive part;solar collector area of 28 m^(2),hot water storage tank volume of 1.4 m^(3),mass flow rate of 800 kg/h on the collector side,mass flow rate of 400 kg/h on the heat exchanger side,and output power of auxiliary heat source of 5∼9 kWwere the optimal constructions for active heating system.Test results showed that during the heating period,the system could provide sufficient heat to the room under different heating modes,and the indoor temperature reached over 18°C,which met the heating demand.The economic and environmental benefits of the system were analyzed,and the economic benefits of the systemwere better than coal-fired heating,and the CO_(2) emissionswere reduced by 3,292.25 kg compared with coalfiredheating.The results of the study showed that the combinedactive-passiveheating systemcouldeffectively solve the heating problems existing in rural buildings in Southern Xinjiang,and it also laid the theoretical foundation for the popularization of the combined heating systems.

Feasibility Analysis on the Integrated Application of Solar Energy, Biogas, Coal-fired Boiler and Radiant Floor Heating for Rural Residence

The feasibility of adopting a balanced energy mix mode (domestic solar energy, biogas, coal-fired boiler and radiant floor heating) was proposed. Taking a typical rural residence in Zhengzhou City for example, the study through theoretical analysis and calculation showed that such a balanced energy mix is an economic way and efficient in saving energy and reducing air pollution, and elaborated the theoretical feasibility of popularizing such a heat supply mode in rural areas.

A simulation Study on the System Combined Solar Energy with Biogas Boiler for Floor Radiant Heating and Fuel

A mathematical model was built for simulating an innovative design system combined solar energy with biogas boiler for floor radiant heating and fuel. Effects of the ambient air temperature on the performance of the system had been examined. And the results also support theoretical feasibility of the system.

On-Line Life Monitoring Technique for Tube Bundles of Boiler High-Temperature Heating Surface

High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.

Equation of Radiation Heat Transfer in Multiple Combustion Boiler Furnace of Fluidized Bed and Pulverized Coal Firing

The equation for radiation heat transfer in a multiple combustion boiler furnace with nuidized bed and pulverized coal firing is derived from direct calculation of radiation heat transfer.

Power Generation Systems Using Continuous Blowdown Waste Heat from Drum Boilers Driving an Organic Rankine Cycle

提出了一种利用汽包锅炉排污系统余热的有机朗肯循环发电系统,有机工质回收扩容器疏水的热量,并通过气轮机发电。建立了系统的热力性能分析模型,并对R227ea、RC318、R236ea、R245fa、R245ca、R123和R113等7种工质的热力性能进行了优化。结果表明,临界温度高的工质,其o2循环的最佳主气温度（蒸发温度）反而低；亚临界循环采用干流体时,过热不利于余热的利用；超临界循环可以改善热源与工质间的温度匹配,有利于增大系统输出功,但是其运行压力高、大比热区的传热恶化等问题是实际运行和设计需要考虑的因素；R236ea的热力性能优于其余6种工质。

The Application of Radiation Shields for Thermal Control of Superheater Tubes in Boiler

Superheater tubes temperature control is a necessity for long lifetime, high efficiency and high load following capability in boiler. This study reports a new approach for the control strategy design of boilers with special shields. The presented control strategy is developed based on radiation thermal shields with low emissivity coefficient and high reflectivity or scattering coefficient. In order to simulate the combustion event in boiler and heat transfer to superheater tubes, an effective set of computational fluid dynamic (CFD) codes is used. Results indicate a successful identification of over- heated zones on platen superheater tubes and effect of radiation shields for solving this problem.

An Efficient Method for Heat Recovery Process and Temperature Optimization

Flue gas heat loss accounts for a significant component of theoverall heat loss for coal-fired boilers in power plants. The flue gas absorbsmore heat as the exhaust gas temperature rises, which reduces boiler efficiencyand raises coal consumption. Additionally, if the exhaust gas temperatureis too high, a lot of water must be used to cool the flue gas for the wetflue gas desulfurization system to function well, which has an impact onthe power plant’s ability to operate profitably. It is consequently vital totake steps to lower exhaust gas temperatures in order to increase boilerefficiency and decrease the amount of coal and water used. Desulfurizationperformance may be enhanced and water use can be decreased by reasonableflue gas characteristics at the entry. This study analyzed the unit’s energyconsumption, investment, and coal savings while proposing four couplingstrategies for regulating flue gas temperature and waste heat recovery. Agraded flue gas conditioning and waste heat recovery plan was presentedunder the condition of ensuring high desulfurization efficiency, along withthe notion of minimizing energy loss owing to energy inflow temperaturedifference. Numerical results show that the proposed methods improved thesystem performance and reduced the water consumption and regulated theboiler temperature.

电厂锅炉实验虚拟仿真系统建设与应用

为开展能动专业核心课程“锅炉原理”的实验教学,校企合作开发了电厂锅炉实验虚拟仿真系统。基于两相流动与辐射对流传热原理构建的仿真系统,由风烟和汽水两大模型构成,严格遵守质量、能量、动量守恒方程。变负荷虚拟实验显示,随锅炉负荷增加,热效率降低、燃料耗量增加。根据辐射传热原理,结合火焰平均温度计算发现:只有炉膛出口烟温增加,才能保证炉膛传热负荷增加,继而抬升排烟温度,导致排烟热损失变大、锅炉热效率降低。锅炉原理实验虚拟仿真,可训练学生运用锅炉本体热力计算原理分析问题的思维,是落实创新能力培养的重要举措。

水蒸气载热式锅炉烟气余热回收系统的节能量测量方法

烟气余热回收可有效降低锅炉的排烟热损失,减少燃料耗量和温室气体排放。近年来,作为一种高效的全热热回收方式,水蒸气载热式锅炉烟气余热回收系统已在实际工程中得到一定的应用,但由于其流程及能量转化关系较为复杂,人们对该系统节能量如何判定存在争议。本文在分析烟气余热回收系统及其各环节的能量平衡与转化关系基础上,提出了采用温度传感器、热计量表等常规仪表间接测量整个余热回收系统及其锅炉助燃风预热节能量的方法,并以山东临邑恒利热电厂为例给出了采用水蒸气载热式锅炉烟气余热回收前、后的测量结果。数据分析表明,对于蒸发量为176.90 t/h的锅炉,整个烟气余热回收系统的总节能量为10.86 MW,占锅炉产热量的8.46%,其中通过锅炉的进风预热加湿使锅炉加热助燃风节能1.73 MW,占余热总回收量的16%。该测量方法为水蒸气载热式锅炉烟气余热回收系统规模化应用提供了节能量在线实时监测的技术支撑。

新疆克州地区学校建筑供暖系统设计研究

研究了新疆克州地区某中学供暖系统设计的思路和流程,包括热源的选择、供暖系统设计,换热站设计等,深入探讨和分析了调试过程中出现的问题,对设计和施工阶段需要关注的设计调研、施工规范等关键环节进行了总结与反思,并提出了解决方案。

超大型侧吹熔池熔炼余热锅炉烟气流动及烟尘黏附研究

富氧侧吹熔池熔炼广泛应用于铜、铅、锌等有色金属的提取,其后端的余热锅炉承载着余热回收利用、沉降烟尘的重要作用。但在实际生产过程中,炉内烟气流场混乱,烟尘易黏附积灰,炉壁与部件磨损严重等,导致了余热回收效率降低,低负荷运行甚至被迫停机。针对上述问题,采用多相网格质点方法,对年处理150万t精矿超大型富氧侧吹熔池熔炼余热锅炉内烟气流动特性、烟尘沉降与黏附开展数值模拟研究。结果表明:炉内的烟气涡旋会导致烟尘回流至入口烟道;挡板前移会导致挡板受击与堵塞情况加剧;增大挡板间距能有效减小挡板的堵塞;增大辐射室空间能大幅度减小挡板受到的冲击。

燃煤锅炉改燃兰炭燃烧工艺及效益分析

兰炭因热值高、硫含量低的特点被广泛应用于散煤替代,燃煤锅炉改燃兰炭是实现资源合理利用、降低污染物排放和改善企业经济效益的有效途径。以河北某循环流化床锅炉改燃兰炭工程为例,燃烧系统采用掺烧灰渣的方法,解决改燃后机械未完全燃烧导致损失大和物料循环不稳定问题,确定了兰炭和灰渣的最佳掺混比为9∶1;配风系统采用控制总量并降低一次风率的方法,解决兰炭着火困难的问题,确定了最佳一次风比例为55%;换热系统采用增加锅炉尾部受热面的方法,解决因燃料热值提升较大产生的蒸汽超温和锅炉效率下降问题。改燃扩容后锅炉烟尘、SO2和NOx排放分别比原锅炉降低了73%、94%和55%,以原锅炉35 t/h的额定功率运行,每小时节约燃料成本5.51%,产吨蒸汽所需燃料成本降低6.47元。

湿法锌冶炼过程中对余热锅炉安全的探索与实践

湿法锌冶炼过程中余热锅炉的安全至关重要。宝徽集团主要针对余热锅炉的爆管现象和积灰问题,对余热锅炉安全进行了改造实践。改造后,余热锅炉进气口烟气的流速明显降低,有效降低了爆管风险,余热锅炉的安全性大大提升。清灰方式升级为弹簧振打、爆破共同作用后,清灰效果显著增加,管道积灰现象改善。

基于水蓄热的热源厂蒸汽调峰技术

基于工业供汽负荷波动大、昼夜偏差显著的现状,将水蓄热技术与热源厂热力生产工艺相结合,提出采用蒸汽-除盐冷水的间接换热技术、环氧富锌漆防腐技术和硬质聚氨酯发泡保温技术,并对形状、容积和高径比等罐体结构优化设计,旨在开发一种适用于工业供热的蒸汽调峰技术。实践应用表明,基于水蓄热的热源厂蒸汽调峰技术具有稳定高效、简单易操和投资收益显著等优点。本技术还可应用于燃煤机组实现深度调峰、消纳新能源发电等场景,具有重要的现实意义。

Analysis of Influencing Factors on NO_x emission in Gas-Fired Heating and Hot Water Combi-Boilers Based on Orthogonal Method

In order to determine the sensitivity of influencing factors on NOx emission in gas-fired heating and hot water combi-boilers,the orthogonal method was adopted in this paper.Five predominant factors affecting the formation of NOx and four levels were selected to be analyzed,including the diameter of flue restrictor,power of fan,ejection distance of nozzle,aperture of nozzle and relative humidity of air.The test plan was designed by employing L16(45)orthogonal array,and 16 groups of experiments were conducted.The test results were analyzed with range analysis and variance analysis.The results indicated that the power of fan has the greatest influence on the formation of NOx of the gas-fired combi-boilers,followed by the diameter of flue restrictor and the relative humidity of air,while the ejection distance of nozzle and aperture of nozzle have little effect on the formation of NOx.In addition,with the selected optimal combination of five factors,a minimum NOx volume fraction is obtained,which confirms the superiority of the orthogonal test.The research finding has a certain guiding significance for the reduction of NOx formation of gas-fired heating and hot water combi-boiler.

适用于一次调频能力在线监测的锅炉蓄热系数计算方法

锅炉蓄热系数是衡量火电机组一次调频能力的重要参数,实际运行中随着机组工况变化,但目前仿真中多忽略变工况下的蓄热系数变化对调频能力的影响。为准确掌握机组运行中真实的一次调频能力,需要在线确定蓄热系数。基于IEEE标准模型的框架,提出适用于一次调频能力在线监测的锅炉蓄热系数计算方法。建立考虑工质流动与传热过程的锅炉热力系统动态模型。以某1000 MW超临界机组为算例,结果表明所提出的变工况锅炉蓄热系数算法能更准确地描述一次调频过程中热力参数的动态变化。一次调频60 s内积分电量相较于IEEE标准模型减小62.4%。且低负荷下蓄热系数大,蓄热释放速率慢。该方法能根据现场实时数据确定当前工况下的蓄热系数,可应用于一次调频能力在线监测。

燃气-蒸汽联合循环发电余热锅炉烟道均流装置数值模拟与优化

燃气-蒸汽联合循环发电中燃气轮机与余热锅炉主体经常采用大扩张角过渡段连接,导致下游烟气流动不均匀,影响余热锅炉NOx选择性催化还原烟气脱硝效率。对此,提出通过布置三级导流板来改善烟道内烟气的流动均匀性,并采用计算流体力学模拟方法研究过渡段导流板布置形式、安装角度及布置密度等参数对烟道内烟气流动特性的影响规律。结果表明:未设置导流装置时过渡段出现明显漩涡,涡度可达20 m-1,导致烟气流动均匀性差;过渡段安装一级变倾角导流板可显著抑制漩涡的尺寸,安装二级变倾角导流板可显著改善过渡段内烟气流动均匀性,但是烟道后端烟气速度均匀性仍不高,安装三级导流板可同步改善过渡段和烟道内烟气流动均匀性,在换热模块三之后相对速度标准差系数降至2.1%。优化的导流板布置为:一级导流板水平投影长度2.25 m,间距1.20 m,角度15°~30°等差递增;二级导流板水平投影长度1.36 m,间距1.40 m,角度15°~60°等差递增;三级导流板长度0.70 m,间距1.00 m,水平安装。研究结果可为烟气均流装置的设计提供理论指导。

吸收-压缩热泵回收高水分杂醇烟气余热研究

为了处理煤化工过程中产生的有害副产杂醇并回收热能,本文设计了一台以杂醇为燃料的热水锅炉,并在锅炉尾部加装了一种新型吸收-压缩复合热泵来回收烟气余热,通过Aspen Plus软件对热泵回收烟气余热流程进行模拟。结果表明杂醇烟气蕴含丰富潜热,采用该新型热泵能实现余热有效回收,额定工况下能使锅炉热效率提高11.01%。进一步研究了压缩机压比、回水温度和锅炉负荷对热泵性能的影响,并提出分别基于节能和碳减排效果的热泵性能系数COP_(a)和COP_(e)来全面分析热泵的运行性能。结果发现在压比为9.6时热泵COP_(a)和COP_(e)最高,且在压比小于9.6时,热泵性能会受回水温度升高的影响较大。随着锅炉负荷的增大,热泵系统的COP_(a)和COP_(e)先增大后减小。本文研究可为高水分烟气余热的深度回收和新型复合热泵的应用提供一些理论依据。