Kalina地热发电热力循环效率影响因素分析

结合Kalina循环系统的工作原理,采用EES软件平台编制计算软件,并完成了系统循环过程的模拟计算,计算结果与实际运行参数吻合较好。在此基础上,对Kalina地热发电循环进行分析,从冷凝水温度、汽轮机入口压力以及氨的质量浓度等方面研究对循环效率的影响。结果表明,系统循环效率随着汽轮机入口压力存在峰值,随基本溶液中氨的质量浓度的升高而升高,但氨的质量浓度过高就要求发生器换热面积过大,造成系统整体经济性下降。此外,还对汽轮机的安全运行进行了分析。     

卡林纳循环——新型的动力装置

一、前言 近来一种新的热力循环引起了美国电力工业界很大的兴趣,因为它声称比常规的蒸汽朗肯循环具有优越得多的性能。这就是通常以其首创人命名的卡林纳循环(Dr. Alexander I. Kalina)。实际上它乃是一种以氨-水混合物为工质的改进型朗肯循环,工作过程中氨水的浓度有所改变来收取更大的能量,发出更多的功率,同时循环中透平排汽的余热也将部分回收,用于一个特殊的蒸馏-冷凝单元,使氨-水得以在常温下凝结,形成有利的背压,再打入锅炉循环使用。 氨-水作为一种非共沸物质(Non-azeotropic Substance),在一定的压力下,其蒸发沸     

地热源非共沸工质向心透平的热力性能分析

为了分析确定的热源条件下,即循环吸热量相同时,工质特性与透平热力性能的约束关系。根据热力学和透平设计理论,选取6种非共沸工质,基于计算各工质循环参数,通过对各非共沸工质向心透平分别进行热力设计,分析不同工质透平的热力性能差异。结果表明:M4工质透平的轮周效率和定熵效率最高,M2工质透平的绝对效率和实际输出功率最高。理想循环效率由热源条件和工质特性决定,对透平热力性能影响显著。各工质透平的实际输出功率与定熵效率不存在一致的对应关系,而绝对效率与实际输出功率具有一致性。因此,基于热源条件、工质特性和透平热力性能之间的耦合关系,选择适用于透平的工质,以保证透平能够具有良好的热力性能。     

低温太阳能热力发电有机朗肯循环工质的选择

为了筛选出适宜于低温太阳能热力发电有机朗肯循环的工质,根据 PR 状态方程计算和分析了采用 11 种低沸点有机流体工质的低温太阳能发电朗肯循环的热力性能.结果表明:随着工质临界温度的升高,有机透平进口处的最大蒸发压力基本呈下降趋势;在凝结温度与有机透平进口温度一定的情况下,临界温度越高的流体,其循环热效率越高;使用正已烷和正戊烷能获得较高的循环热效率,凝汽器中的凝结压力比较适中,是比较适合用作低温太阳能热力发电有机朗肯循环的工质.     

一种新型高效海洋温差能热力循环性能研究

为提高海洋温差能发电循环效率,提出一种带有2条回热支路的新型高效海洋温差能热力循环系统,基于热力学第一定律建立新循环系统数值计算模型对其进行理论数值研究。研究分析工质浓度、透平进口压力和海水温度对循环性能的影响。研究结果表明:随工质浓度的增加,循环系统热效率和系统净输出功均先增大后减小;随透平进口压力的增加,循环热效率和净输出功均呈先增后减的趋势;循环热效率随冷海水温度的升高而降低,随温海水温度的升高而升高。另外,将提出的循环系统效率与Uehara循环、Yoon循环分别在其相同工况下进行比较,结果显示该循环系统效率最高。     

吸收升温Kalina循环的模拟及实验研究

以冰岛Kalina地热电厂为研究对象,在不影响原设计热电并供的前提下,以增加系统发电量为目标,结合吸收式热泵基本原理,提出吸收升温Kalina循环。采用EES(engineering equation solver)工程计算软件编写热力学计算程序对吸收升温Kalina循环进行模拟验证。在理论分析的基础上,针对该循环的核心部件——吸收升温子系统,搭建吸收升温实验台,对影响吸收升温子系统升温性能的主要因素进行实验研究。结果表明,吸收升温Kalina循环比冰岛Kalina地热电厂的发电量更高。较高的热源温度有助于提高实验台的升温性能,但是较高的冷源温度对实验台的升温性能具有抑制作用。保证吸收器管内流体处于湍流阶段有助于提高实验台的升温性能,同时流量比(稀溶液泵流量与液氨泵流量的比值)的增大在一定程度上也有助于提高实验台的升温性能,但是超过最佳流量比则对实验台升温性能没有帮助。     

15kW等级闭式海洋温差KSC-11发电系统的性能分析

对15kW等级混合工质海洋温差卡林纳-11循环(简称KSC-11)系统进行计算和分析。结果表明,对于给定的透平进口压力,KSC-11系统存在相对应的最佳氨质量分数。对于给定氨质量分数的KSC-11系统,也存在相对应的最佳透平进口压力。在可利用海水温差19℃条件下,15kW等级KSC-11系统中,氨质量分数对最大净功影响不大,对应最佳透平进口压力为0.60～0.75MPa;氨质量分数为0.95的KSC-11系统综合性能最好,单位净功产量的换热器总面积γ为6～7m2/kW,对应的最佳透平进口压力为0.75MPa。     

创新的Kalina循环可提高电厂效率

Kalina循环的特点是采用氨/水作为工作流体。据报道,它的效率大大高于采用最新技术的蒸汽电厂循环。文章介绍了其实验厂的首次试运行结果,电厂热力学及其实际应用     

利用地热尾水的吸收压缩复合式热泵(ACHP)的性能研究

针对不同热源温度、制热温度、循环倍率及溶液浓度等条件,对以氨水溶液为工质的ACHP系统进行理论分析和热力计算。计算结果表明,利用低温地热尾水为热源的ACHP系统用于提供城市区域供热具有较高的COP和较低的压缩比,并得到ACHP系统热力性能随热源温度、制热温度、溶液浓度、循环倍率变化的趋势,为溶液浓度和循环倍率的优化选择提供理论依据。     

钢铁厂高炉煤气燃气轮机循环热力分析

建立了钢铁厂燃用高炉煤气的简单循环燃气轮机装置模型,根据经典热力学和燃气轮机循环理论编制了循环热力性能计算程序,计算了循环功率和效率随压比的变化关系。结果表明存在不同压比分别使循环功率和效率达到最大值,提高涡轮进口燃气温度和降低煤气压缩机进口温度有利于提高循环性能。     

First law-based thermodynamic analysis on Kalina cycle

Based on the first law of thermodynamics, and adopting the Peng-Robinson equation (P-R equation) as the basic equation for the properties of ammonia-water mixtures, a thermodynamic analysis on a single-stage distillation Kalina cycle is presented. A program to calculate the thermodynamic properties of ammonia-water mixtures, and that for calculating the performance of Kalina cycles, were developed, with which the heat-work conversion particulars of Kalina cycles were theoretically calculated. The influences on the cycle performance of key parameters, such as the pressure and temperature at the inlet of the turbine, the back pressure of the turbine, the concentration of the working solution, the concentration of the basic solution and the cycle multiplication ratio, were analyzed.     

First law-based thermodynamic analysis on Kalina cycle

Based on the first law of thermodynamics, and adopting the Peng-Robinson equation (P-R equation) as the basic equation for the properties of ammonia-water mixtures, a thermodynamic analysis on a single-stage distillation Kalina cycle is presented. A program to calculate the thermodynamic properties of ammoniawater mixtures, and that for calculating the performance of Kalina cycles, were developed, with which the heatwork conversion particulars of Kalina cycles were theoretically calculated. The influences on the cycle performance of key parameters, such as the pressure and temperature at the inlet of the turbine, the back pressure of the turbine, the concentration of the working solution, the concentration of the basic solution and the cycle multiplication ratio, were analyzed. __________ Translated from Journal of Power Engineering, 2007, 27(2): 218–222 [译自: 动力工程]     

Application of modified Kalina cycle in biomass chp plants

This paper presents alternatives to Kalina cycles typically used in place of the organic Rankine cycle in biomass power plants. Overviews of both Rankine and Kalina cycles are given alongside the possibilities of using biomass as a viable energy source and recommended guidelines from the engineering practice for selection and management of these cycles. Benefits of Kalina novel bottoming cycle (and the alternative cycles presented herewith) over the Rankine cycle are the higher thermodynamic cycle efficiency and lower capital expenditures combined with the possibility of using low-grade heat sources, such as biomass or waste heat from exhaust gases. Analysis of ammonia-water binary system under various operating conditions has been performed for all the proposed cycles based on the published references and it has been shown that the proposed alternative models prove to be simpler and to have similar or even greater thermodynamic efficiency compared with the Kalina novel bottoming cycle.     

Exergoeconomic analysis and optimization of basic,dual-pressure and dual-fluid ORCs and Kalina geothermal power plants: A comparative study

In present work, the basic, dual-pressure and dual-fluid ORCs and Kalina cycle for power generation from the geothermal fluid reservoir are compared from energy, exergy and exergoeconomic viewpoints. To do so, first thermodynamic models are applied to the considered cycles; then by developing cost flow rate balance and auxiliary equations using SPECO method for all components, the cost flow rate and unit cost of exergy for each stream are calculated. The results show that the turbine in basic and Kalina cycles and low pressure turbine in dual-pressure and dual-fluid ORCs have the maximum value of sum of total cost rate associated with exergy destruction and total capital investment cost rate. Thus, more attention should be paid for these components from the exergoeconomic viewpoint. The cycles are optimized to obtain maximum produced electrical power in the cycles as well as minimum unit cost of produced power. The optimization results show that among the considered cycles, dual-pressure ORC has the maximum value of produced electrical power. This is 15.22%, 35.09% and 43.48% more than the corresponding values for the basic ORC, dual-fluid ORC and Kalina cycle, respectively in optimal condition. Also Kalina cycle has the minimum value of unit cost of power produced and its value in optimum state is 26.23%%, 52.09% and 66.74% less than the corresponding values for the basic ORC, dual-pressure ORC and dual-fluid ORC, respectively in optimal condition. Finally a parametric study is carried out to assess the effects on thermodynamic and exergoeconomic parameters of the considered cycles of operating pressures and ammonia mass concentration.     

Double-lift absorption refrigeration cycles driven by low–temperature heat sources using organic fluid mixtures as working pairs

At present, much interest is being shown in absorption refrigeration cycles driven by low temperature heat sources, such as solar energy or low-grade waste-heat. Double-lift absorption cycles working with ammonia-water have been recommended for refrigeration applications which require cold at 0°C and which are activated by waste heat between 70 and 100°C. This paper discusses the potential of the organic fluid mixtures trifluoroethanol (TFE)-tetraethylenglycol dimethylether (TEGDME or E181) and methanol-TEGDME as working pairs in series flow and vapour exchange double-lift absorption cycles. The ammonia-water mixture was used for comparison purposes. The results show that the performances of these cycles improve significantly when they have the above mentioned organic fluid mixtures as working pairs. For example, the coefficient of performance of the vapour exchange cycle working with TFE-TEGDME is 15% higher than with ammonia-water. In this study, we used a modular software package, which we developed for the thermodynamic properties and cycles simulation of absorption systems.     

A comparative thermodynamic analysis of Kalina and organic Rankine cycles for hot dry rock: a prospect study in the Gonghe Basin

Hot dry rock is a new type of geothermal resource which has a promising application prospect in China. This paper conducted a comparative research on performance evaluation of two eligible bottoming cycles for a hot dry rock power plant in the Gonghe Basin. Based on the given heat production conditions, a Kalina cycle and three organic Rankine cycles were tested respectively with different ammonia-water mixtures of seven ammonia mass fractions and nine eco-friendly working fluids. The results show that the optimal ammonia mass fraction is 82% for the proposed bottoming Kalina cycle in view of maximum net power output. Thermodynamic analysis suggests that wet fluids should be supercritical while dry fluids should be saturated at the inlet of turbine, respectively. The maximum net power output of the organic Rankine cycle with dry fluids expanding from saturated state is higher than that of the other organic Rankine cycle combinations, and is far higher than the maximum net power output in all tested Kalina cycle cases. Under the given heat production conditions of hot dry rock resource in the Gonghe Basin, the saturated organic Rankine cycle with the dry fluid butane as working fluid generates the largest amount of net power.     

A preliminary study of the kalina power cycle in connection with a combined cycle system

Combined cycle systems have been recognized as efficient power systems in which exhaust gas from the topping cycle provides the available energy to the bottoming cycle. Since most heat sources available to the bottoming cycle are sensible-heat sources, there may be a better thermal match, and an increase thermodynamic efficiency, on reducing the entropy generation of the simple combined cycle. To increase the efficiency of the Rankine cycle working with sensible heat, two conventional methods have been proposed: one is to incorporate a multipressure boiler; the other is to implement a supercritical cycle. An alternative method is to use a multicomponent working fluid boiling at a variable temperature with a change in the liquid composition of the components, and yielding a better thermal match with the sensible-heat source than the constant temperature boiling process. The Kalina cycle is an implementation of this concept, where ammonia/water mixtures are used as the working fluid. The purpose of this study is to conduct a preliminary study of the Kalina power cycle system in connection with a combined cycle system, comparing the Kalina cycle and the Rankine cycle. This study is performed using new thermodynamic properties of ammonia/water mixtures developed by the authors.     

地热驱动氨水吸收式动力/制冷复合循环参数优化分析

针对中低品位地热驱动的氨水吸收式动力/制冷复合循环的热力学性能展开分析与优化,在Kalina循环的基础上利用氨水变温蒸发的特性,将正向动力子过程与逆向制冷子过程耦合,对外实现动力与冷量的联供。本文对影响复合循环热力性能的工质对浓度x_w/x_b、氨水发生温度（露点温度）t₁₄、循环倍率K以及分流比n四个重要参数展开了分析优化。研究表明,在x_w/x_b=0.50/0.32、t₁₄=180℃、K=2.80和n=0.505的优化工况下,复合循环的热效率和?效率分别可达19.38%和59.77%,较氨水动力循环分别高出3.71%和4.74%,较水蒸气朗肯循环分别高出8.54%和35.81%。     

Nuclear energy-driven Kalina cycle system suitable for Indian climatic conditions

Kalina cycle (KC) has been contemplated as one of the energy-efficient power generation cycles. It is suitable for various waste heat recovery applications. It is one of the competitors to Organic Rankine Cycle, Transcritical Cycle, Supercritical Cycle, and Rankine cycle. Kalina cycle system (KCS) is a binary mixture system that utilizes ammonia-water as working fluid. In this work, a parametric study has been made with a low-temperature Kalina cycle system (LTKCS) and a high-temperature Kalina cycle system (HTKCS). The LTKCS utilized the hot source energy from solar energy, whereas for HTKCS the hot stream of energy was received from a pressurized water nuclear reactor. The output and efficiencies (energy, exergy, and relative) were noted for a range of limits for the parameters considered. Separator temperature and turbine concentration have been considered as common parameters for the two KCSs. For LTKCS and HTKCS, the optimum working conditions for separator temperature and turbine concentration exist in the range 110?150°C, 60?100°C and 0.85–0.97, 0.50–0.80, respectively. The optimized values for LTKCS and HTKCS have been derived. Among the two KCSs, HTKCS produces high specific power (675 KW). The optimum value of exergy efficiency results for LTKCS (74%) pertaining to low exergy losses. Energy is recovered more efficiently in LTKCS. This study suggests that KCS is well suited for low-temperature applications.