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纸机干燥部热力系统的分析与研究-党睿-2009

2013年06月17日 11:52 党睿 点击:[]

 

 作者姓名  党睿
 中文论文题名  纸机干燥部热力系统的分析与研究
 外文论文题名  ANALYSE AND RESEARCH FOR THERMODYNAMIC SYSTEM IN DRYER SECTION OF PAPER MACHINE
 论文提交日期  2009-06-25
 学位年度  2009
 中文论文关键词  造纸机,干燥部,热力系统,蒸汽喷射式热泵,喷射系数
 外文论文关键词  paper machine, the dryer section, thermodynamic system, steam ejector, entrainment ratio

 

中文论文文摘


    能源是制约发展的瓶颈,如今社会能源供求矛盾越来越突出,节能降耗也是造纸业十分关注的问题,同时也是提高造纸行业利润的重要途径之一。就制浆造纸各个环节的能耗而言,纸机干燥部是能耗最大的工段,所以合理设计纸机干燥部尤其是热力系统与节省建设投资、提高生产能力、保证成品质量和降低生产成本有着极为重要的关系。
    长久以来,影响和制约纸机车速、产量及能耗的主要问题在于纸机供热系统中冷凝水排除不良,为此对于纸机干燥部供热系统的研究国内外一直没有停止过。纸机干燥部热力系统的发展大致历经了由单段供汽到多段供汽再到如今比较常用的热泵供汽系统。自从热泵系统问世以来,我国绝大多数纸机的改造均采用了带有蒸汽喷射式热泵的热力系统。热力系统的设计与布置、热泵性能的好坏和控制系统的优劣都会直接影响纸机的运行效果。对于新建纸机或原有纸机热力系统的改造,不可能一味的采用统一模式,所以要研究一套针对特定参数的纸机热力系统的设计方法。本文主要对纸机热力系统、热泵装置及烘缸装置进行了分析与研究,研究的主要内容如下:
(1)全面的比较和分析了纸机干燥部热力系统的各个环节,指出各种系统的优点与缺点,在进行纸机干燥部的设计时,应考虑多种因素的制约,理性合理的采用最适用的技术,选取最适合的计算参数。
(2)对热力系统的主要参数计算进行了研究,提出了纸机干燥部热力系统设计实施的一般步骤,讨论选取了计算参数,并采用VB语言编写了计算程序,使烦琐的计算初步程序化,提高了此方面的研究速度。
(3)对蒸汽喷射式热泵在纸机干燥部热力系统的应用做了充分的研究,在学习总结前人计算经验的基础上,对比了不同的喷射系数计算方法,得出热力学计算喷射系数较为准确;提出了针对不同汽源热力系统的热泵设计方法;采用计算流体力学(CFD)软件技术对热泵进行了模拟,验证了本文中的设计方法并进行了模型选优,用Pro / E软件进行了结构造型。
(4)对多喷嘴热泵进行了研究;做了多喷嘴热泵模型与普通热泵模型的三维模拟对比,由模拟对比得出,多喷嘴热泵在其结构和功能上都有巨大的优势。
(5)按照某造纸厂提供的参数,设计实施了一套3200 / 350纸机的热力系统,并设计一台蒸汽喷射式热泵,使研究与实践相结合。
(6)对多通道烘缸做了理论分析及用Pro/ E软件进行了结构造型,获得国家实用新型专利ZL200820029564.8。

 

外文论文文摘


    Energy is a bottleneck of restricting the development. The contradiction of energy supply and demand now becomes more and more obviously. Energy saving has been paid more attention which is an important method to improve papermaking industry’s profit. On all aspects of pulp and paper in terms of energy consumption, the paper machine dryer section is the largest section, so the reasonable design of paper machine dryer section, in particular the thermal system, and to save construction investment, improve productivity, ensure product quality and reduce production cost has a very important relationship.
    For a long time, there is a major problem that condensate water can’t be excluded easily in the thermodynamic system, affecting and restricting paper machine’s speed and energy consumption. So the research of thermodynamic system in the dryer section of paper machine has never stopped in the world. For thermodynamic system in the dryer section of paper machine, it develops generally from a single-stage to multi-stage supplying steam system and then now to heat pump supplying steam system. Since the heat pump supplying steam system came out, the vast of paper machines used this method to improve their heat supplying system in our country.
    How to design and arrange thermodynamic system, how to make the heat pump’s function best, and how to bring control system in full play, these factors affect normal operation of the paper machine. To build a new paper machine or improve an original thermodynamic system can not only adopt unified model blindly, it is necessary to study a set of machine-specific parameters of the thermal system design. In this paper, the thermodynamic system on the machine, heat pump and dryer installed devices were analyzed with the study as follows:
(1) All areas about drying section were analyzed in this paper. Pointing out that the constraints as well as the advantages and disadvantages, the main parameter of thermodynamic system be analyzed and researched. It should be given a variety of factors, rational and reasonable to use the most applicable technology, to select the most suitable parameters.
(2) The main parameters of the calculation in thermal system were researched to implement the general steps of machine dryer section design. The VB compiled language made the calculation easy and increased the speed of this research.
(3)This paper studied theory and mechanism in-depth of steam ejector used in the dryer section. Based on the grand old men’ experience, contrasts different calculation means to calculate entrainment ratio. The result is thermodynamic mean for steam ejector entrainment ratio calculation is exact. For different thermodynamic system this paper gives different means to design heap pump. Use CFD software to simulate the steam ejector’ fluent flow. Through those simulating we can find the best way to design steam ejector to achieve the purpose of increase pressure-gradient and energy saving. Finally Pro/E software was used to create structure.
(4)The multi-nozzle ejector was studied. Compared the conventional ejector’s model with multi-nozzle ejector’s model, contrast obtained by the simulation that, multi-nozzle ejector has a huge advantage in its structure and function.
(5)On the base of analysis and research above, a set of 3200/350 paper mill’s drying section was designed according to the parameters which a paper mill providing. In addition, a steam ejector to this drying section was designed.
(6)The theory and mechanism of multi-port dryer were analyzed in this paper. The Pro/E software was used to create structure, and the patent ZL2008200295648 was obtained.
    

 

 

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