分体式热管换热器在火电厂烟气余热回收中的应用

在火力发电厂中,由于燃煤质量下降和锅炉换热面积灰等原因造成锅炉排烟温度升高一直是亟待解决的难题之一。以大连某热电厂烟气余热回收工程为例,采用分体式热管换热器回收锅炉排烟余热,用来加热补充除氧器的除盐水,对烟气的回收利用进行技术和经济效益分析。实践应用证明分体式热管换热器在火电厂烟气余热回收中提高机组效率、减少煤耗的可行性和实用性。     

热管技术在锅炉余热回收中的应用

本文介绍了热管的基本原理,对锅炉烟气余热回收系统进行了设计与实施,对余热理论回收效果进行了分析并与实际效果进行了对比。结果表明:热管换热器在锅炉烟气余热综合回收利用效果好,降低了燃料消耗,具有较好的经济效益与环保效益。     

吸收式热泵技术在电厂烟气余热回收中的应用探讨

利用烟气深度降污余热回收换热器+吸收式热泵机组回收烟气中的余热量,为用户供暖,实现低温余热资源再利用的同时,进一步降低了烟气中的SO2和烟尘的排放,提高了电厂的综合能源利用效率,并实现了烟气的超低排放要求。     

余热回收与热管换热器

论述了节能在世界范围内的重要意义,指出对烟气余热进行回收利用具有很高的经济利益,分析了五种常用于烟气余热回收的换热器的优缺点,着重阐述了热管换热器受到普遍欢迎的原因。     

热管及其换热器在烟气余热回收中的应用

简要介绍了热管技术,并分析了其传热机理。热管换热器具有许多独特的优点,已经获得了广泛的工业应用,应用主要集中在中低温余热资源回收利用方面,应完善高温热管,以拓宽热管换热器在高温余热资源中的应用。     

基于余热回收的热管换热器应用研究

介绍了热管换热器的工作原理和设计优点,并阐述了热管对其工作介质的要求以及工业余热回收中热管换热器的应用问题。结合某钢厂高温冲刷水余热回收的实例,对热管换热器进行了详细的设计与计算,并把余热回收的热量加以利用,即作为冬季供暖的热源,使得该项目获得了较好的经济效益。分析了热管换热器在余热回收中的技术、经济、环境的可行性,为热管换热器在余热回收的应用提供了借鉴。     

余热回收用热管及热管式换热器的研究

简要介绍了热管及热管式换热器的工作原理,热管式换热器在工业余热回收中的应用,以及热管式换热器运行过程中防止积灰和低温腐蚀等问题的有效措施。     

关于热管余热回收技术的探讨

从热管换热效率、换热器体积、使用寿命、经济性及其他四个方面,论述了热管技术不适合应用于烟气余热回收换热器中的原因.     

50t炼钢电弧炉烟气佘热回收系统的设计应用

以电弧炉炼钢过程烟气余热的回收利用及烟气净化除尘为主线,以热管蒸发器为换热元件,合理控制烟气流速,解决高温烟尘的沉降和蒸发器热管灰堵以及烟气温度波动大的难题,完成了50t电弧炉烟气余热回收净化系统设计与施工.对电弧炉炼钢过程中所产生的高温烟气直接进行余热回收,满足电弧炉炼钢流程VD真空处理对蒸汽的需求,实现了高温烟气余热回收利用和环境净化,为国内电弧炉节能降耗和清洁生产进行了有益的探索.     

余热回收与热管换热器

论述了节能在世界范围内的重要意义,指出对烟气余热进行回收利用具有很高的经济效益。分析了五种常用于烟气余热回收和的热换器的优缺点,着重阐述了热管换热器受到普遍欢迎的原因。     

The latent heat recovery from boiler exhaust flue gas using shell and corrugated tube heat exchanger: A numerical study

The excessively increasing environmental concerns along with reducing fossil fuel resources introduce the trend of increasing the efficiency of boiler via implementing waste heat recovery. In the present study, the potential of latent heat recovery is investigated in the middle‐size boiler exhaust flue gas using the shell and corrugated tube heat exchanger. The main purpose of the present study is efficiency growth in flue gases using latent heat recovery of the steam energy. The heat recovery analysis is evaluated by a validated computational fluid dynamics model by a commercial software. For this study, the effect of different tube arrangements, number of tubes, and flow direction in the shell on heat transfer and pressure drop were investigated. The results showed that in‐line arrangement of the tubes in the shell presents better thermal performance and also high pressure drop among the other arrangements. As a result, by considering the thermal performance and pressure drop, radial arrangement shows higher performance. According to the obtained results from Section 2 of the present study, by considering the radial arrangement of tubes in the shell, as the number of tube rises, the thermal performance declines.     

Thermodynamic analysis of an LNG fuelled combined cycle power plant with waste heat recovery and utilization system

This paper has proposed an improved liquefied natural gas (LNG) fuelled combined cycle power plant with a waste heat recovery and utilization system. The proposed combined cycle, which provides power outputs and thermal energy, consists of the gas/steam combined cycle, the subsystem utilizing the latent heat of spent steam from the steam turbine to vaporize LNG, the subsystem that recovers both the sensible heat and the latent heat of water vapour in the exhaust gas from the heat recovery steam generator (HRSG) by installing a condensing heat exchanger, and the HRSG waste heat utilization subsystem. The conventional combined cycle and the proposed combined cycle are modelled, considering mass, energy and exergy balances for every component and both energy and exergy analyses are conducted. Parametric analyses are performed for the proposed combined cycle to evaluate the effects of several factors, such as the gas turbine inlet temperature (TIT), the condenser pressure, the pinch point temperature difference of the condensing heat exchanger and the fuel gas heating temperature on the performance of the proposed combined cycle through simulation calculations. The results show that the net electrical efficiency and the exergy efficiency of the proposed combined cycle can be increased by 1.6 and 2.84% than those of the conventional combined cycle, respectively. The heat recovery per kg of flue gas is equal to 86.27 kJ s^?1. One MW of electric power for operating sea water pumps can be saved. The net electrical efficiency and the heat recovery ratio increase as the condenser pressure decreases. The higher heat recovery from the HRSG exit flue gas is achieved at higher gas TIT and at lower pinch point temperature of the condensing heat exchanger. Copyright © 2006 John Wiley & Sons, Ltd.     

嵌入热管换热器的反烧锅炉节能-脱硫功效研究

嵌入热管换热器的反烧锅炉,以热管换热器、紊流炉排、火焰稳定器等部件和反烧结构实现燃煤低温燃烧,热释放的平均温度为700—800℃;同时燃煤燃后的灰渣和化合物充当吸附和固硫剂,为炉内脱硫提供了条件。经测试,其烟气排放二氧化硫浓度仅为600mg／m3（122℃）,脱硫效率约84．2％,在低成本运行条件下实现较高效率的脱硫,综合经济技术指标等于或高于集中供热锅炉。     

降低燃气锅炉排烟热损失方法探讨

燃用天然气的锅炉其排烟温度较高，除带走大量显热之外，烟气中还存在大量水蒸汽的潜热，若将这两部分热量充分回收，则将大幅度提高锅炉热效率。文章在对天然气的燃烧特性计算的基础上，分析燃气锅炉烟气潜热回收的效果和需要解决的问题。     

垃圾焚烧烟气余热利用的探讨

从利用烟气干燥物料的角度对干燥过程的认识、焚烧烟气的组成、烟气流动动力、烟气干燥模型、新型焚烧炉的特点、烟气温度的衡算等方面作了些分析与探讨。这对中小型焚烧炉烟气余热回收利用及其它工业炉降耗增效都具有一定的意义。     

Experimental study on titanium heat exchanger used in a gas fired water heater for latent heat recovery

In general, latent heat recovery is usually accompanied by the corrosion of the heat exchanger, which is caused by the strongly acidic condensate when the temperature of the flue gas is lowered below the acid dew point. The present study has been conducted to investigate the heat and mass transfer characteristics in a titanium heat exchanger with excellent corrosion resistance used for waste heat recovery with the condensation arranged in a gas fired water heater. In addition, the thermal efficiency of the gas fired water heater was evaluated based on the net calorific value at the maximum rated output during latent heat recovery from the exhaust flue gas. Parametric studies were conducted for the flue gas flow rate, inlet temperature and mass flow rate of the supplied water, respectively. Different arrangements of the tubes of the heat exchanger including in-line and staggered configurations were investigated. The experimental results indicate that the thermal efficiency of the gas fired water heater with a latent heat recovery (LHR) heat exchanger was enhanced by about 10% compared with conventional instantaneous water heaters, i.e., water heaters without heat recovery. In addition, in terms of the Nusselt number and the Sherwood number, the heat and mass transfer performance of the staggered tube bank type were approximately 50% and 10% higher than that on the in-line tube bank type when the Reynolds number of the flue gas was 10³.     

有机热载体锅炉尾部高效余热利用装置的设计与应用

有机热载体锅炉广泛应用于纺织、印染行业,由于高温定型和染整的特殊工艺以及有机热载体锅炉的构造和运行原理造成其尾部排烟温度在300℃左右,产生巨大的热能浪费。为减少热能损失,通过高温烟气的余热回收利用,提高有机热载体锅炉的综合热效率,可实现节能降耗和减排。本课题运用热管技术设计研制了结构合理、操作方便、高效的有机热载体锅炉尾部高温烟气的回收再利用装置。     

石墨烯-PFA复合材料换热器与金属换热器的传热性能对比

氟塑料换热器以其耐腐蚀、耐磨损等优点而备受关注,但氟塑料热导率较低,换热能力差,限制了其广泛应用。石墨烯-PFA复合材料兼具石墨烯优异的导热性和可熔性聚四氟乙烯(PFA)良好的耐酸碱腐蚀性,是新一代的换热器材料。搭建了余热回收测试实验台,对石墨烯-PFA复合材料换热器和金属换热器的传热性能进行对比。研究了不同烟气流速、不同进口烟气温度以及不同石墨烯配比对复合材料传热性能的影响。结果表明:对于金属换热器和复合材料换热器,当烟气流速从2.0增加到4.0 m/s时,传热系数分别增加到原来的1.19和1.34倍;随着进口烟温的升高,两种材质的传热系数分别降低了15.6%和14.7%;随着石墨烯含量增加,复合材料的导热系数以及传热系数均增加。     

烟气余热回收利用的可行性研究

烟气余热回收装置是一套用烟气热量加热吸热介质的装置。从投资、运行等各方面,针对设置烟气换热器的工程,分别阐述其有利及不利因素,并进行比较,从而论证安装烟气余热换热器具有很大的社会效益和经济效益。