水和水蒸汽热力性质IFC公式通用计算软件

回顾了水和水蒸汽热力学性质的通用计算方法，比较了国际上影响较大的几种模型，并在此基础上探讨使用ＩＦＣ模型建立水和水蒸汽通过计算软件包所波及的变量组合，一维、二维非线性方程迭代算法及针对水和水蒸气计算模型的特点实现变量分离以斯提高计算速度等问题?还介绍了“水和水蒸汽热力性质的ＩＦＣ公式通用计算软件包”的使用及其在线调用库函数的有关情况。     

动力工程中水蒸汽性质的通用计算软件包

本文针对动力工程实际应用中，水和水蒸汽热力学性质的计算需求，对水和水蒸汽热力学性质的通用计算方法进行了回顾，比较了在国际上影响较大的几种典型计算模型后，提出并探讨了使用ＩＦＣ公式，建立水和水汽通用计算软件包涉及到的诸如变量组合、一维、二维非线性方程迭代计算法以及针对水和水蒸汽计算模型的特点实现变量分离以求得计算速度的提高等种种问题。文章最后介绍了“水和水蒸汽热力性质的通用计算软包－ＳＰＣＳ”的使用     

新的水和水蒸汽热力性质国际标准IAPWS-IF97及计算软件

介绍了最新的工业用水和水蒸汽热力性质国际标准ＩＡＰＷＳ－ＩＦ９７的特点及根据该标准计算公式编写的计算软件。该软件在Ｗｉｎｄｏｗｓ下运行，并可与Ｅｘｃｅｌ等软件调用，可供锅炉、汽轮机等设计、运行、试验等的技术人员使用。     

水和水蒸汽热力性质IAPWS-IF97公式及通用计算模型

通过IFC 67公式和IAPWS IF97公式的对比,介绍了IAPWS IF97公式的新特点,并依据IAPWS IF97公式,提出了水和水蒸汽热力性质的通用计算模型。同时,介绍了在此计算模型的基础上作者编制的水和水蒸汽热力性质计算软件。通过使用表明,IAPWS IF97公式具有计算速度快,计算精度高等很多优点,其已经成为新的国际标准。     

水和水蒸汽性质的IAPWS-IF97计算模型

介绍了新型的水和水蒸汽性质计算模型-国际水和水蒸汽性质协会提供的1997年工业用计算模型（简称IAPWS-IF97），并与IFC67模型进行对比，讨论了IAPWS-IF97模型的计算速度和分区边界上的一致性。图2表1参4     

水和水蒸汽热力性质国际工业标准IAPWS-IF97 和计算程序编制

介绍了水和水蒸汽热力性质国际工业标准IAPWS—IF97和它相对于原有工业标准IFC-67的优越性,以及基于该标准编制的水和水蒸汽热力性质计算程序。该程序功能全面、界面友好,可供所有要用到水和水蒸汽热力性质的人员使用。     

Excel平台下97版水和水蒸汽性质汽轮机热力性能考核试验计算软件的开发

介绍了东方汽轮机厂在Microsoft Excel平台下，按照ASME PTC6-1996试验规程要求，独立自主地开发出97版水和水蒸汽性质汽轮机热力性能考核试验专用计算软件。该软件已能够完全满足工程计算的精度要求，对东方汽轮机厂汽轮机性能考核试验工作具有重大的促进作用。     

临界区水和蒸汽的热力性质计算

在水蒸汽临界区的定义和划分的基础上，论述了临界区内热力性质的计算方程和方法。     

水和水蒸汽表计算程序WaterPro for Windows

水和水蒸汽表计算程序是能源工程常用的程序，采有MS-Fortran5.1在Windows环境下编制的WaterPro程序能够计算水和水蒸汽的饱和温度，饱和压力，焓h,熵s，比容v，yong(exergy),并提供了16位动态连接库water.dll，可用于Windows下的与水和水蒸汽性质计算有关的应用软件开发，如用于电厂设计和热力循最优化的复杂计算等等。     

水和水蒸汽物理性质拟合多项式

水和水蒸汽热力性质图表是从事热力工程设计和研究不可缺少的基础资料。它包括水和水蒸汽的状态参数(压力、温度、比容、焓、熵)和物理性质参数(动力粘度、导热系数、比热、普朗特数)。工程上常用近似的数学表达式来描述这些图表参数,以适应电子计算机计算的要求。根据汽轮机行业当前使用的需要和我国电子计算机容量的现况,选取了适中的图表使用范围,利用最小二乘法原理通过计算机自动拟合计算优选出以二元多项式表示的水和水蒸汽热力性质方程,拟合的原始数据取自水和水蒸汽热力性质图表(文1)。数年前拟合所得的水和水蒸汽状态方程和根据实用需要随后拟合的若干补充方程曾     

低参数单缸多级汽轮机热力计算程序开发

在回顾了水和水蒸汽热力性质的通用计算方法基础上,采用动态数组的方式,直接对水和水蒸汽热力性质表数据进行插值求解。并采用一种比较合理的计算模型,克服采用高级语言流程化编程进行汽轮机热力计算的缺陷,采用VB6.0语言,对单缸多级汽轮机热力计算进行了研究并编制了相应的计算程序,所开发的计算程序可用于分析单缸汽轮机通流部分的设计。     

Quick evaluation of the thermodynamic properties of water and steam

The calculation of thermodynamic properties of water and steam is familiar but sometimes too slow. Some older equations with lower precisions but faster calculation speeds are therefore tested. Some new simple equations for evaluating the thermodynamic properties of water and steam are demonstrated. The deviations from precise equations are on average less than a few per cent if the calculations are made in some limited regions. Bigger deviations occur at the surrounding of the critical point and in the evaluation of the specific volume. It is shown that a quick evaluation of thermodynamic properties of water, saturated vapor and superheated steam is possible with these simple equations. The precision of the simple equations could be regulated by changing the size of the evaluated region.     

Generation of Steam Tables Using Artificial Neural Networks

The industrial formulations for the thermodynamic properties of water/steam, which are approximations of the scientific one, are intended to be used in applications where computational speed is of importance, such as in power plant modelling and control. The traditional methods for implementing these tables in software imply either the use of polynomial algorithms, which demand long iteration times, or look-up tables, which require a large memory capacity. On the other hand, there is a group of useful tools, called Artificial Neural Networks (ANNs), that have been successfully applied for pattern recognition and function approximation tasks in, for instance, the areas of medicine, engineering, and economics. This paper aims to show the potential of ANNs for generating the water/steam tables. ANNs enable the production of user-friendly software, which furthermore increases the computational speed while sustaining good accuracy. This new approach avoids the limitations of the traditional methods and can be advantageously implemented in heat and mass balance programs to speed up calculations. Promising results obtained with this technique are highlighted in the present paper, demonstrating the reliability of using ANNs in lieu of polynomials algorithms and look-up tables.     

Performance analysis on a new multi-effect distillation combined with an open absorption heat transformer driven by waste heat

In this paper, a new water distillation system, which consists of either a single- or multi-effect distiller combined with an open absorption heat transformer (OAHT), has been proposed.The new integrated system can be used for distilling waste water with high amounts of SiO₂ from heavy oil production, and the resultant distilled water can be supplied to steam boilers to produce high quality steam which in turn is injected into oil reservoirs to assist with heavy oil recovery. The thermodynamic cycle performances for these new integrated distillation systems were simulated based on the thermodynamic properties of the aqueous solution of LiBr as well as the mass and energy balance of the system. The results indicate that combined with OAHT, the waste heat at 70 °C can be elevated to 125 °C and thereby produce steam at 120 °C in the absorber, which is able to drive a four-effect distiller to produce distilled water. For a single-effect and four-effect distiller, the coefficients of performance (COP) are approximately 1.02 while the performance ratios are 2.19 and 5.72, respectively. Therefore, the four-effect distillation system combined with an OAHT is more thermally effective and is an ideal option to process the waste water in oilfields.     

双列调节级的变工况热力计算方法及应用

对一种双列调节级的热力计算方法作了介绍。在仅需已知该级的有关几何特性等参数时,用此方法便可较快地获得包括级后蒸汽焓在内的调节级热力特性。它可应用于供热机组的简化热力计算。     

机组旁路系统减温减压装置热力特性的计算机分析

基于ＩＦＣ公式和一维搜索法实现水蒸气热力性质的计算机计算和水蒸气焓－－熵图的计算机查找,利用两相流理论和可压缩流体动力学原理,把水蒸气与冷却水混合流动多级多孔节流问题转化为非线性方程的迭代求根问题,实现了机组旁路系统减温减压装置热力特性的计算机分析。     

冷却水流程数对凝汽器热力性能的影响

电站凝汽器可以设计成冷却水双流程和单流程。利用自行开发的凝汽器工作特性数值模拟软件PPOC3．0模拟和分析了冷却水流程数对电站凝汽器的热力性能的影响,结果表明单流程凝汽器比双流程凝汽器有更高的热负荷和更小的汽侧阻力。     

Energetic and exergetic analysis of a hybrid combined‐nuclear power plant

Combined‐cycle power plants are currently preferred for new power generation plants worldwide. The performance of gas‐turbine engines can be enhanced at constant turbine inlet temperatures with the addition of a bottoming waste‐heat recovery cycle. This paper presents a study on the energy and exergy analysis of a novel hybrid Combined‐Nuclear Power Plant (HCNPP). It is thus interesting to evaluate the possibility of integrating the gas turbine with nuclear power plant of such a system, utilizing virtually free heat. The integration arrangement of the AP600 NPP steam cycle with gas turbines from basic thermodynamic considerations will be described. The AP600 steam cycle modifications to combine with the gas turbines can be applied to other types of NPP. A simple modeling of Alstom gas turbines cycle, one of the major combined‐cycle steam turbines manufacturers, hybridized with a nuclear power plant from energetic and exergetic viewpoint is provided. The Heat Recovery Steam Generator (HRSG) has single steam pressure without reheat, one superheater and one economizer. The thermodynamic parameters of the working fluids of both the gas and the steam turbines cycles are analyzed by modeling the thermodynamic cycle using the Engineering Equation Solver (EES) software. In case of hybridizing, the existing Alstom gas turbine with a pressurized water nuclear power plants using the newly proposed novel solution, we can increase the electricity output and efficiency significantly. If we convert a traditional combined cycle to HCNPP unit, we can achieve about 20% increase in electricity output. This figure emphasizes the significance of restructuring our power plant technology and exploring a wider variety of HCNPP solutions. Copyright © 2011 John Wiley & Sons, Ltd.     

Parametric analysis and assessment of a coal gasification plant for hydrogen production

The purpose of this paper is to conduct a parametric study to show the best steam to carbon ratio that produces the maximum system performance of an integrated gasifier for hydrogen production. The study focuses on the energy and exergetic efficiency of the system and hydrogen production. The work is completed using computer simulation models in Engineering Equation Solver software package. This software is used for its extensive thermodynamic properties library. An equilibrium based model is used to determine the performance of the system. The data is presented in graphs which show the chemical composition in molar fractions of the syngas, the overall energy and exergy efficiency of the system, and the hydrogen production rates. A study of these parameters is conducted by varying the steam to carbon ratio entering the gasifier and the ambient temperature. It is observed that the higher the steam to carbon ratio that is achieved the more hydrogen and more power the plant is able to produce. Because of this, the exergy and energy efficiency of the system increases as the steam to carbon ratio increases as well. It is also observed that the system favors a lower ambient temperature for maximum exergy efficiency and hydrogen production.