中小型低温多效海水淡化装置应用软件开发

发布时间：2018-04-16 14:04

本文选题：海水淡化 + 低温多效　；参考：《大连理工大学》2014年硕士论文

【摘要】：目前,随着科技发展、人口增长、污染加剧,淡水资源匮乏的问题日益严峻。在这样的背景下,海水淡化技术作为一种可以增加淡水资源总量的技术手段而备受关注。其中的LT-MED(低温多效蒸馏)技术因其操作温度低,不易结垢,装置组合方式灵活,可利用多种形式的低品位热源等优点成为海水淡化领域的主流方法之一。本文着眼于热水驱动的中小型LT-MED系统,对此类系统的工作特点及其设计方法进行了分析总结。给出了水和水蒸汽物性参数及海水沸点升高的计算方法。考虑海水物性的变化,以及沿程阻力的影响,建立了包括预热器、蒸发器、冷凝器、闪蒸罐等各换热设备在内的此类系统的数值模型,设计了系统的循环迭代计算方法并绘制了计算框图。采用FORTRAN95和Visual Basic多语言混合编程的方法编写了中小型LT-MED系统的可视化设计计算程序,开发出友好的人机对话界面。运用DLL(动态链接库)技术实现两种语言的结合,发挥了FORTRAN语言运算能力优秀和VB界面设计功能强大的优点,获得了较好的程序性能。编写程序时,采用模块化编程的方法,可以实现六种不同设计条件下的系统的热力学计算,输出各换热设备进出口温度、焓值、质量流量及各效热负荷、产水量等相关参数,并且可以将最后结果以Excel的形式导出,便于设计人员对不同设计参数进行比对分析,优化设计结果。并可以对换热器的结构进行设计在此基础上,对热水驱动的中小型MED系统在与之结合的热源系统的运行参数发生变化时系统性能的变化情况进行了研究。对某一确定结构的系统而言,系统产水率、各效产水率、各换热设备热负荷、各换热设备实际传热温差、海水实际浓缩比等参数均随着输入热量的增大而增大；而各效喷淋密度及各换热设备传热系数则随输入热量的增大而呈减小趋势,同时,单位热量产水率随输入热量增大而减少。
[Abstract]:At present, with the development of science and technology, population growth, pollution, shortage of freshwater resources is a serious problem. Under this background, the seawater desalination technology as a technical means can increase the total amount of freshwater resources has attracted more and more attention. The LT-MED (LT-MED) technology because of its low operating temperature, no scaling device, flexible combination method, the advantages of using low grade heat source in various forms and become the main method of seawater desalination.
This paper focuses on small and medium sized LT-MED system in hot water drive, the work characteristics of this kind of system and its design method are analyzed. The calculation method of the properties of water and steam and water boiling is given. Considering the change of the water properties, and the influence of frictional resistance, including the establishment of the preheater, evaporator, condenser the numerical model of this system, the heat exchanger, the flash tank, the design of iterative calculation method for system and draw the calculation diagram.
Methods FORTRAN95 and Visual Basic hybrid programming program visualization design of small LT-MED system, develop the friendly man-machine dialogue interface. Using DLL (Dynamic Link Library) to realize the combination of the two languages, FORTRAN language has the advantages of excellent operation ability and powerful VB interface design, the program performance better. When you write a program, using the method of modular programming, can achieve six different thermodynamic system design under the condition of the calculation, the output of the heat exchanger outlet temperature, enthalpy, mass flow and the effect of heat load, water production and other related parameters, and the final results will be derived the form of Excel, so that the designer of the different design parameters were compared and analyzed, the result of optimization. And we can design the structure of heat exchanger.
On this basis, to the change of system performance in small MED system of hot water driven changes in the operating parameters of heat source system with time are studied. For a system to determine the structure of the system, water production rate, water production rate of each effect, the heat exchanger heat load, the change thermal equipment actual heat transfer temperature difference, the actual water concentration ratio and other parameters are increased with increasing heat input; and the effect of spray density and the heat transfer coefficient increases with the increase of heat input decreased, at the same time, the unit of heat water production rate with the heat input quantity decreases.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P747

【参考文献】