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集中供热系统中影响用户供热质量的最大问题是热网的水力失调问题.无论是直供还是间供系统的热网,系统水力失调已成为当前普遍存在又难以解决的难题,直接影响供热质量,同时造成能源浪费. 相似文献
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浅析供热系统中平衡阀的应用 总被引:1,自引:0,他引:1
针对供热系统水力失调问题,提出了为彻底解决水力失调状况平衡阀的作用,介绍了平衡阀的分类和特性、阀门流量系数的计算及平衡阀的选用,说明了平衡阀的安装位置、注意事项及安装平衡阀带来的经济节能效益。 相似文献
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差压控制器在热水供热系统的实际应用 总被引:1,自引:0,他引:1
热力系统水力失调问题严重影响着供热系统正常运转。本文对自力式差压控制器原理进行分析和论述,通过地区热网的热平衡改造实际应用,有效解决了长期困扰热力系统水力失调的问题。 相似文献
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由于传统供热系统普遍存在水力失调及能源浪费比较严重的现象,目前,供热系统采取了各种节能技术措施解决以上问题。介绍北京市顺义区港馨西区供热系统采取的水力平衡、气候补偿器等主要的节能技术措施,结合该小区具体情况说明供热系统采用节能技术措施的必要性及供热效果。 相似文献
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综合治理供热系统水力失调 总被引:1,自引:0,他引:1
本文叙述供热系统水力失调、失调度和水力失调原因,提出解决水力失调的两种途径,分析"附加压头平衡"技术的特点和应用的条件,论证综合治理方案选择的效益准则. 相似文献
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集中供热热网系统节能措施 总被引:1,自引:0,他引:1
针对集中供热管网热损失中,热、电消耗所占的比例大的问题,采用预制保温管和管道直埋敷设技术,有效地减少管网的散热损失。通过保证管网的水力失调度,减少热网中水泵的耗电量。采用热网的变流量调节,减少耗电量。加强对热网的管理,降低失水率。 相似文献
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分析了江苏油田供热系统的现状,针对油井供热管线水力失调严重的问题进行理论研究,提出了解决问题的途径和方法,现场应用后有效提高了能源利用效率。 相似文献
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水在热网运行当中,是主要的介质,大量失水会使热网出现水力失调、用户室温低等危害。要保证系统平稳运行,就必须大量补水,其结果是锅炉、管网、用户系统内腐蚀加剧,堵塞增多,锅炉补水量加大,热效率低,由此给企业带来的损失也是很大的。 相似文献
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通过建立考虑密度变化的三维CFD(计算流体动力学)模型,对单相自然循环条件下水平换热回路的流动特性进行了研究。在稳态流动分析中,首先通过三维CFD模型,获取了加热管道的径向温度和速度分布,发现管道截面温度场和速度场均为不均匀分布,这分别是由径向自然对流和对流换热系数决定的;其次,应用量纲分析的方法,整理归纳系统无量纲参数间的线性关系。在非稳态分析中发现水平换热通道出现不规则复杂流动,证明了混沌现象的存在,产生这种现象的原因是自然循环的特性与回路布置方式双重作用的结果。 相似文献
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冲击热负荷条件下的自然循环是工程中常见的汽液两相流动与传热过程 ,同时也是一个复杂的非稳态过程。转炉余热锅炉是一种典型的运行于冲击热负荷下的大型换热设备 ,冲击热负荷严重地影响着其水循环流动特性 ,从而影响它的寿命。在实验模拟氧气顶吹炼钢转炉余热锅炉的实际工作过程的基础上 ,研究了冲击热负荷、压力和初始速度等因素对不稳定传热和流动的影响。实验结果表明 ,自然循环在受到冲击热负荷后 ,水循环流量迅速达到最大值 ,呈现较快的响应速度 ,随后在最大流量附近脉动。循环流量的主要影响因素是冲击热负荷的强度 ,而压力和初始速度对循环流量的影响则较小。 相似文献
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G.H. Su 《Applied Thermal Engineering》2009,29(14-15):3160-3168
Experimental and theoretical studies of single-phase natural circulation flow and heat transfer under a rolling motion condition are performed. Experiments with and without rolling motions are conducted so the effects of rolling motion on natural circulation flow and heat transfer are obtained. The experimental results show the additional inertia caused by rolling motion easily causes the natural circulation flow to fluctuate. The average mass flow rate of natural circulation decreases with increases in rolling amplitude and frequency. Rolling motion enhances the heat transfer, and the heat transfer coefficient of natural circulation flow increases with the rolling amplitude and frequency. An empirical equation for the heat transfer coefficient under rolling motion is achieved, and a mathematical model is also developed to calculate the natural circulation flow under a rolling motion condition. The calculated results agree well with experimental data. Effects of the rolling motion on natural circulation flow are analyzed using the model. The increase in the flow resistance coefficient is the main reason why the natural circulation capacity decreases under a rolling motion condition. 相似文献
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Solar space heating with warm air in typical air collectors and rock bed storage systems involves constant air flow rates and varying the temperature of supply to rooms and to storage. This practice results in undesirable fluctuations in comfort levels in the living space, excessive storage size, useful but inaccessible heat in storage, and unnecessarily high energy consumption for air circulation and auxiliary heat. These drawbacks can be avoided by use of a practical controller and variable speed fan to provide heated air from the collector at constant temperature and a continually varying flow rate. Collector manufacturer's data, confirmed by seasonal tests on a solar air heating system in Solar House II at Colorado State University, have been used in simulations at constant hot air supply temperatures of 40°, 50°, and 60°C, and at one typical constant flow rate of 49 kg/h per m2 through a 50 m2 collector and rock bed storage unit, providing approximately half the seasonal heating requirements of a residential building. Auxiliary heat requirements and fan power use in the 40°C and 50°C constant temperature operations were significantly reduced from the levels prevailing under constant flow conditions. Collection efficiency and solar heat supply at constant flow were slightly higher than values at the 60°C constant temperature level. 相似文献
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The surface heat flow distribution in the Bradano Trough (southern Italy) is examined in the light of temperature distribution at depth, reconstructed on the basis of data from deep oil wells. The effects of groundwater circulation and the related problem of inferring deep thermal conditions from surface heat flow have been studied by mathematical models. Groundwater effects are certainly important in the zones close to the recharge areas, whereas far from these areas we cannot even establish whether water circulation has a significant effect on surface heat flow. 相似文献