直接换热式供暖系统的研究

发布时间：2018-02-28 17:16

  本文关键词： 供暖系统 尾气能量回收器 直接换热 安全节能 数值模拟 实验研究　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：冬季供暖对城市稳定和居民生活影响很大,舒适的居住和工作环境能够体现社会的进步与发展。据初步估算,我国每年平均用于冬季供暖所消耗的能源量折合成人民币约为700亿元,占全国能源总消费的1/4。现有的供暖系统普遍存在“低安全、高耗能、高污染”问题,构建“安全、节能、清洁”的供热系统,意义重大,任重而道远。本文结合目前冬季日常供暖情况,设计一套新型独立分户式供暖系统。供暖系统主要包括供暖装置、供暖自控系统、供暖安全启闭阀、供暖换热水池等几个部分,采用直接接触式传热技术,强制流动顺流式热水供暖,集成安全、用水、燃烧连锁控制功能。对供暖系统中各项关键技术性能开展模拟和测试研究,并分析供暖系统能量损耗及污染问题,提出有效改善措施,力求实现冬季供暖更安全、更环保、更高效。采用计算流体力学(CFD)Fluent软件,基于Realizable k-ε湍流模型、DPM离散相模型和混合组分输运模型,对系统供热之源——供暖装置内部气水直接接触式换热过程进行数值模拟研究。研究结果表明:供暖装置内部负压分布稳定,且远低于大气压力,无“爆炸”安全隐患;进气口右端高温气体扩散区,气水热质交换效果最佳;气水接触换热产生了大量的水蒸气,排放尾气温度较高,供暖装置内部工况较差,湿度较大。参照GB/T10180-2003相关标准,开展供暖系统供热实验研究。得出日常供热工作的各项热工参数(如:供热热量、流量、尾气温度等)。通过正平衡法,计算出供暖系统整机供热效率为83.8%。针对系统排放尾气的余热及水蒸气浪费问题,提出安装尾气能量回收装置,回收尾气能量,实现尾气能量再利用。采用热管与冷凝双重能量回收技术,研发出一款尾气能量回收器,其主要受热载体为外纵向翅片管,内部换热面积高达4.2m2。在尾气能量回收效果测试中,尾气能量回收器回收尾气热量为90.4kJ/s,供暖系统整机工作效率可提高1.5%。尾气能量回收器内部温差5.43℃,水蒸气温度骤降,遇冷凝结,被回收。同时尾气可凝污染物溶于冷凝水中,排放物得到了净化,有效缓解了大气热污染和颗粒物污染。为掌握供暖系统中供暖装置与尾气能量回收器实际工作情况,开展整机实验测试。测试结果表明:换热系统整体水温平均每小时升高4.619℃。其中,供暖装置换热量占总换热量的76%;尾气能量回收器换热量占总换热量的24%。本文是对供暖系统研究的一次创新尝试,形成了一套较为完整成型的供热研究体系,研究成果具有一定的实用价值,可为后续进一步研究工作提供参考与借鉴。
[Abstract]:Winter heating has a great impact on urban stability and residents' lives. A comfortable living and working environment can reflect the progress and development of society. According to preliminary estimates, The average annual energy consumption for heating in winter in China is about 70 billion yuan, accounting for 1 / 4 of the total energy consumption in the country. The existing heating systems generally have the problems of "low safety, high energy consumption and high pollution" and construct "safety and energy conservation." The clean heating system is of great significance and has a long way to go. According to the current situation of daily heating in winter, this paper designs a new type of independent household heating system. The heating system mainly includes heating equipment, heating automatic control system, Heating safety valve, heat exchanger pool and other parts, using direct contact heat transfer technology, forced flow downstream hot water heating, integrated safety, water, The function of combustion chain control. The key technical performance of heating system is simulated and tested, and the problems of energy loss and pollution of heating system are analyzed, and effective improvement measures are put forward to realize more safe and environmentally friendly heating in winter. Using CFD fluent software, based on Realizable k- 蔚 turbulence model, DPM discrete phase model and mixed component transport model. A numerical simulation study on the gas-water direct contact heat transfer process in the heating system is carried out. The results show that the distribution of negative pressure in the heating device is stable and far lower than the atmospheric pressure, and there is no "explosion" safety hazard. In the high temperature gas diffusion zone at the right end of the inlet, the effect of gas-water heat and mass exchange is the best, the gas-water contact heat transfer produces a large amount of water vapor, the exhaust gas temperature is high, the internal working condition of the heating device is poor, and the humidity is larger. Referring to the GB/T10180-2003 standard, The experimental study of heating system is carried out. The thermal parameters of daily heating work (such as heat supply, flow rate, tail gas temperature, etc.) are obtained. The heating efficiency of the whole heating system is calculated to be 83.8%. In view of the waste heat of exhaust gas and the waste of water vapor, the installation of exhaust gas energy recovery device is put forward to recover the exhaust gas energy. Using heat pipe and condensation dual energy recovery technology, a exhaust energy recovery device is developed. The main heat carrier is external longitudinal finned tube, and the internal heat transfer area is up to 4.2 m2. In the test of tail gas energy recovery effect, The exhaust heat recovered by the exhaust energy collector is 90.4 kJ / s, and the working efficiency of the whole heating system can be improved by 1.5 鈩，

本文编号：1548231