严寒地区分散采暖炊火余热利用的几种方法

<正> 火墙带火炕是近年来开始在中、小城镇试用的一种采暖炊火余热利用的形式。效果良好,深受广大用户欢迎。火墙带火炕要比不带火炕的火墙散热均匀,蓄热效果好。单烧的火墙,火和烟通过上下往复的洞散热,各洞受热非常不均。而火墙     

炕墙火墙式大坯花洞炕

炕墙火墙式大坯花洞火炕的特点,是一炉多用,既可用一个炉灶解决做饭、烧炕,又可烧火墙解决室内取暖.炕墙火墙的高度为500毫米,与一般炕墙一样,只是炕墙火墙的宽度是240毫     

内置挡板火墙式火炕设计研究

设计一种新型的内置挡板的火墙式火炕系统。设计将火墙式火炕划分为冬、夏2种工况运行。冬季烟气流入炕下通过加热炕板间接为室内提供热量;夏季烟气流入炕内墙烟道,途中经过集热对流管束,加热对流管束内冷水,用于夏季淋浴,此时烟气不经过炕下,可避免夏季炕面过热的情况。该新型系统通过不同季节控制烟气的流向,合理有效地避免了炕面冬冷夏热的情况,提高人类居住环境的舒适度。     

浅析火炕与低温地面辐射供暖住宅的生态节能性

调查表明火炕仍然是我国北方小城镇和农村住宅中最重要、最有效的供暖设施;新建的城市住宅中低温地面辐射供暖逐渐普及,其原因在于辐射供暖具有供热均匀、热舒适性好、散热体蓄热性强、节能明显等优点。文中对比普通的暖气供暖,分析了住宅中火炕与低温地面辐射供暖的独特优势,各自的适用场合。最后提出了推广应用火炕与低温地面辐射供暖的建议,以及对火炕的改进建议。     

北方地区火炕供暖技术应用分析

我国北方冬季寒冷且漫长,为了使居住环境更加舒适,人们使用多种供暖设施来提高室内温度。火炕是北方地区农村应用最多的供暖设备,距今已有2 000多年的历史。随着农村居民生活水平的提高,现有的火炕供暖技术已经无法适应社会主义新农村建设的要求,为改变这一现状就要改进火炕供暖技术。从实际应用的角度出发,从内部构造和整体结构方面对传统火炕供暖技术应用进行了分析,从结合火墙采暖以及太阳能采暖对新式火炕供暖技术应用进行了分析,指出通过改进火炕内部结构及整体结构能改善火炕的供暖效果,新式火炕较传统火炕在舒适度和热效率等方面均有所提高,可提高我国北方农村地区农民的生活质量。     

严寒地区节能型村镇住宅热设计

计算公式不完全反映室内热作用规律、计算参数取值不尽合理,是严寒地区村镇住宅外墙保温性能不佳、内表面普遍结露或结霜、室内气温低及浪费能源的重要原因。我国“民用建筑热工设计规程”只适用于集中采暖的建筑,对于严寒地区量大面广的火炕及火墙采暖的村镇住宅外墙的热工设计方法并未提及。我们根据冬季室内热作用规律及现场测量结果,应用建筑围护结构的非稳态传热理论,提出了较为科学的计算公式及计算参数取值方法,从理论上探索了严寒地区村镇靠火炕、火墙     

浅析我省农村住宅现状及节能技术

改进和推广火炕这种在农村住宅中传统的、高效节能的辐射供暖系统,使黑龙江省农村住宅实现生态环保、健康舒适,方法是对佳木斯地区典型村镇住宅现状进行了实地调研,总结了采用不同结构体系及建材的住宅的供暖方式、保温效果、平均能耗以及火炕利用,建筑造价及其耐久性等情况。结果表明农村住宅在冬季仍然普遍采用火炕供暖,但热源单一,构造陈旧等原因使之没能充分发挥其优势;同时,围护结构的热工性能也对室内气候状况影响很大。结论部分提出在农村辐射供暖住宅中综合应用太阳能火炕、地炕和火墙以及围护结构生态节能等切实可行的改进途径,为本省农村辐射供暖生态住宅建设提供必要的参考。     

相变蓄热火墙的结构设计及其性能分析

应用计算流体力学软件分析确定火墙的内部构造形式。选择熔点较高,融解热较大的相变材料,将其封装、制成相变墙板应用于传统火墙壁面。通过计算和模拟分析得出,相变蓄热火墙是一种能有效吸收和利用火墙体内部烟气余热的采暖系统,这种创新式火墙具有较好的应用前景。     

高寒地区乡村住宅的节能设计研究

气温低、风速大、太阳辐射强度及日照率大等,是乡村与城市建筑气候的明显区别。我国北方地区乡村住宅建筑主要采用火墙、火炕采暖。因此,高寒地区乡村住宅建筑的设计,必须以有效地抵御风寒、保温、节能为基本出发点。设计乡村住宅时:既要保温、节能、利用太阳辐射热,又要有效地防止冷风吹袭及过量的冷风渗透;既要确保主要使用房间有足够的温     

寒冷地区小城镇住宅供热模式调研与分析

对我国寒冷地区小城镇现有供热模式进行调研,统计现存供热状况.通过走访调研辽宁鞍山某小城镇4户家庭,并结合其他文献对其供热模式进行分析.通过调研建筑的采暖方式、使用能源、室内环境以及人们对现有采暖方式的满意度等分别进行了调研,总结分析了小城镇现存各种供热模式的结构特点、工作原理、使用能源以及优缺点.火炕和土暖气适合小城镇这种居民分散地区的采暖,通过节能技术可以达到低碳排放,而煤炉采暖供热效率低下,污染严重,应被逐渐取缔.为探讨适用于小城镇供热模式的低碳节能技术提供了一定的参考.     

Hydrogen storage and heat transfer properties for large-capacity double thin-layered annulus ZrCo bed with secondary containment cavity

Fast heat and mass delivery with high cycling stability of the core component, hydrogen storage bed, in SDS are essential for the operation of the future tritium factory in ITER project. However, the aforementioned properties are still perplexing in large-capacity ZrCo bed, especially for that with secondary containment structure required by the actual tritium operation in the future. Herein, the performance including heating, cycling and cooling with two different size ZrCo beds (loading of ZrCo are 200 g and 2000 g respectively) were systematically studied. The experimental data shows that the maximum heating ability of the middle-size/full-scale storage bed are both about 10 °C/min, and the maximum hydrogen absorption capacity of these ZrCo beds are 44.6 L/405.5 L, respectively. Besides, hydrogen pressure and hydrogen retention during the following desorption can affect the cycling performance of the ZrCo bed. The use of transfer pump can reduce the pressure of the bed during the hydrogen desorption process (operated at 500 °C), which inhibits the disproportionation reaction of the ZrCo alloy. However, the degree of hydrogen pressure reduction in two the types of ZrCo bed are different. As a result, the cycling capacity of the middle-size bed (93.4%, lower hydrogen pressure) is higher than the full-scale bed (68.7%, higher hydrogen pressure) after 10 cycles. When the transfer pump was not used and operated at lower temperature (350 °C), the beds cannot release hydrogen completely, and partial hydrogen atoms are retained in the ZrCo alloy. The middle-size bed still maintains a hydrogen storage capacity of 94.5% after 10 cycles, while 75.9% of the hydrogen storage capacity remained for the full-scale bed. Therefore, the increase of hydrogen surplus in ZrCo alloy is helpful to improve its cycling stability. At last, the cooling performances of the beds under 10 different cooling methods were studied. Among the cooling methods, the best cooling rate was achieved by filling nitrogen in the secondary containment cavity and flowing water passing through the cooling circuit of the bed. This work will provide a crucial reference for the design and optimization of the subsequent operation technology of SDS in ITER.     

复合式低焦油固定床生物质气化装置研究

综合分析上吸式固定床及下吸式固定床生物质气化装置各自特点,提出复合式低焦油固定床生物质气化装置,建立生物质原料处理量为600 kg/h的中试规模试验装置并开展研究。研究结果表明:复合式低焦油固定床生物质气化装置具有结构简单、气化效率高、热效率高、碳转化率高、原料适用性广等优点,极大程度提高了燃气清洁程度,对于生物质气化、发电、供热、化石燃料替代等领域的工业化应用起到了极大的推动作用。     

Numerical and experimental analysis of convection heat transfer in passive solar heating room with greenhouse and heat storage

In this paper, heat transfer and air flow in passive solar heating room with greenhouse and heat storage are studied. Thermal insulation of solar heating room has significant effects on temperature distribution and airflow in the heating chamber of this solar system. Heat transfer and air flow in a rock bed, which is used as solar absorber and storage layer, are also studied. If porosity is kept within certain range, increasing the rock size causes an increase of the capability of thermal storage and heating effects; increasing the porosity of thermal storage materials results in an increase of the bed temperature but a decrease of the rock mass. The specific heat capacity and thermal conductivity have a remarkable effect on the average temperature of rock bed. All these factors should be taken into account when designing a solar heating system.     

Heat transfer modelling of spherical particles subject to heating in a fluidized bed

This paper presents an analytical model for analyzing transient heat transfer between a brick particle and air flow during heating in a fluidized bed combustor. Both experimental and theoretical studies were carried out. The experimental investigation provided the temperature distributions at the centers of the spherical particles during heating. These data were presented in the dimensionless form and were compared with the results of the present analytical model. The theoretical investigation included two cases: e.g. Case 1 considered that the surface heat transfer coefficient is only the convection heat transfer coefficient; Case 2 also considered that the surface heat transfer coefficient is the sum of the convection and radiation heat transfer coefficients. Better agreement was found between the experimental data and the theoretical Case 2. The results of this study show that there is a dominant effect of the radiation heat transfer on the temperature distribution.     

内循环流化床生物质气化过程的神经网络模型

基于BP人工神经网络原理,利用MATLAB神经网络工具箱,以实验得到的57组气化实验数据作为样本,建立了一个以加料量和送风量为输入变量,以燃气热值、产气率、碳转化率和气化效率为输出变量,用于描述连续稳定气化过程的内循环流化床生物质气化模型。对模型的隐层节点数和训练周期改变对模拟结果的影响进行了分析,发现当隐层节点数为20,训练步骤为50步,模型的4个输出变量的模拟结果与实验结果相关系数均超过0.95;同时对该模型的预测能力进行了考察,模型预测结果与实验结果吻合良好,证明了该模型具有较强的泛化能力,为生物质内循环流化床气化系统的优化设计和自动控制提供新思路。     

氧量对天然焦蒸汽气化特性的影响研究

在小型流化床(50mm、高1600mm)实验装置上对沛城煤矿天然焦-蒸汽气化反应进行实验研究,考察蒸汽中掺入氧气,共同作为气化介质对气化反应产气量、碳转化率、煤气热值和煤气组分等因素的影响,同时与ASPENPLUS软件对其气化过程的模拟结果进行了对比。实验中,天然焦试样量0.2kg/h,蒸汽量1.05kg/h,气化温度900℃,实验结果表明:气化介质中氧量明显影响天然焦蒸汽气化特性。随着氧含量的增加,初始阶段(0～0.2L/min)煤气产量提高了1.76倍,碳转化率提高了1.94倍,两者均显著增加;随着氧量的进一步增加(0.2～1.0L/min),其增加幅度趋缓,产气量增加1.16倍,碳转化率增加1.34倍。煤气中有效气体(H2+CO+CH4)的体积分数和煤气热值均持续减少,有效气体份额从76.9%下降到54.3%,煤气热值从9.01MJ/m3减少到6.34MJ/m3,而CO2体积分数增加明显,从23.1%增加到37.3%。Aspen模拟结果与实验结果基本一致,具有实际指导意义。     

流化床部分煤气化影响因素研究

在流化床部分气化炉上系统研究了流化风量、给煤量、水蒸气量、床层温度、静止床层高度、煤种、催化剂等因素对煤气成分和热值的影响,研究结果表明:流化风量、给煤量、水蒸气量、静止床层高度对煤气成分的影响较为复杂,4者都存在最佳范围;床层温度是影响煤气成分的主要因素,煤气热值与温度成正比;增加床层高度,有利于H2、CO生成和CH4分解;烟煤的煤气中含有的可燃成分(H2、CO、CH4)含量比无烟煤高,优质烟煤比劣质烟煤更适合于气化;Ca、Na、K等碱土金属化合物对煤气化具有催化作用,且Na2CO3和K2CO3的催化能力比CaO强。     

基于Workbench的固体电蓄热装置换热通道参数优化

为了解决固体电蓄热装置储释热过程的温度分布均匀性问题,需要对蓄热体换热通道结构参数开展优化设计。根据对称性建立了表征空气与蓄热材料传热过程的传热单元,以传热单元平均温度最大和压力损失最小为优化目标,基于ANSYS Workbench的响应面优化模块对蓄热砖的几何参数(高度、宽度、厚度)和换热通道宽度开展优化设计。结果表明：恒定入口流速下,换热通道高度和宽度的增加,对传热单元平均温度的提高影响较小,但是换热通道宽度对压力损失的改变有显著影响;蓄热砖宽度或高度对于蓄热过程平均温度的改变影响明显,水平方向蓄热砖宽度由15 mm增加到40 mm平均温度降低约7.5 K,竖直方向蓄热砖高度由15 mm增加到30 mm整体蓄热温度线性降低(降温幅度7.5 K),竖直方向蓄热砖高度为20 mm、入口温度1 023 K时升温速度达到297.5 K/h;通过传热单元结构参数敏感性分析可知,设计换热通道选择的蓄热砖宽度和高度均不宜过大。     

A design procedure for solar air heating systems

A natural extension of the design procedure for liquid-based solar space and water heating systems is a similar analysis for solar heating systems using air as the heat transfer fluid. In this paper, a solar air heating system incorporating a flat-plate air heater and packed bed thermal storage is described and a simulation model for the system is developed. The results of many simulations of the air heating system are used to establish the relationship between system performance and the system design and meteorological variables. The results are presented in analytic and graphical form, referred to as an f-chart for solar air heating systems. The results of simulations in several widely different climates suggest that the information presented in the f-chart is location independent. Methods of estimating the performance of air heating systems having a collector air capacitance rate and a storage capacity other than those used to generate the f-chart are included. A comparison of the performance of air and liquid based systems is afforded by a comparison of their respective f-charts. The air system is shown to perform better at high load fractions supplied by solar energy than a liquid-based system with the same collector thermal performance parameters.     

On the effect of process temperature on the performance of activated carbon bed hydrogen storage tank

A numerical model is used to investigate hydrogen charging in packed bed storage tank as function of the charging process temperature. The model is based on the solution of the 2D transport equations for mass, momentum and energy in porous media. The equation system is characterized by the existence of adsorption source terms in both mass and energy equations along with very low Mach number flow condition. It was solved using a pressure splitting technique. Results showed that heating effects due to mechanical energy dissipation and to the exothermal character of the adsorption reaction are enhanced at low temperature. They result in a significant tank capacity reduction. This reduction reaches 25% of the total storage capacity as predicted assuming isothermal charging process. Unlike what has been suggested in several previous studies the major part of the tank capacity decrease is mainly due to the decrease of the gas density. Using recently developed activated carbon monolith with a conductivity exceeding 10 W m^?1 K^?1 can help in limiting the heating effect and reducing this capacity limitation. It makes possible the development of packed bed storage tanks that fulfill the DOE recommendations.