环境温度对燃气轮机功热并供装置及联合循环变工况性能的影响

采用动力机械变工况性能解析分析方法,研究了大气温度变化对燃气轮机功热并供和联合循环装置性能影响．指出燃气轮机在带有余热利用的条件下,大气温度的影响明显减弱,并对不同燃气轮机设计参数和蒸汽设计参数影响做了分析比较。     

Refuse-fired,pressurized, fluidized-bed combustion combined cycle analysis

Use of pressurized, fluidized-bed combustion (PFBC) has given a new opportunity to use municipal refuse as fuel for combined gas and steam power cycles keeping the pollutants of sulphur and nitrogen oxides to a minimum at reduced capital cost.In combined gas and steam power cycles, the heat energy in the exhaust gases of a simple gas turbine cycle is used to generate steam in a waste-heat boiler and the generated steam is used in the steam turbine for power generation.The effects of gas turbine pressure ratio and inlet temperature on the main parameters of refuse-fired, pressurized, fluidized-bed combustion combined cycles are determined.The results indicate a maximum combined cycle thermal efficiency and work output at a possible range of optimum pressure ratios between 10 and 12 for a range of gas turbine inlet temperatures of 750–1000°C.     

单轴恒速燃气轮机及其功热并供装置的典型变工况特性

利用作者在本期给出的单轴恒速燃气轮机及其功热并供装置的变工况显式解析解，本文给出它们的变工况典型性能．当变工况性能均以其设计值的比值表示时，不同设计值机组的各种无因次变工况性能曲线均分别在一条狭带之中，尤其是燃气轮机的效率基本就在一条线上，而且此线与实际数据相当符合．对以饱和蒸汽供热的功热并供装置，本文特别指出当设计蒸汽压力较高时，其余热锅炉逼近温差在低工况下很容易变为负值，要注意其安全运转问题．     

Thermodynamic design and assessment of hybrid double absorption solar cooling systems

This communication presents an investigation of the thermodynamic design and feasibility assessment of hybrid double-absorption solar cooling systems. The systems considered are conventional closed-cycle and open-cycle absorption systems with an additional open-absorber component through which the process room air is passed, cooled and dehumidified. The cooling produced in the evaporator is utilized to remove heat from the open absorber as well as the process air being circulated. Thermodynamic modelling of system components for a fixed set of operating conditions and with water-LiBr as working fluid have been carried out and the system COP predicted as a function of regenerator temperature, mass flow ratio and latent heat load in the process air and the ambient air. A comparative study of the open and closed cycle options has been made and detailed parametric results are presented. It is concluded that the hybrid double-absorption solar cooling systems are better in performance than conventional systems and an open-cycle double-absorption system is even more attractive and cost effective as compared to closed-cycle option.     

Cogeneration by combining gas turbine engine with organic rankine cycle

The gas turbine engine is known by its relatively low efficiency especially at part load. Therefore, to conserve energy and reduce the operating cost, waste heat is recovered by combining a heat-exchange gas turbine cycle with closed organic Rankine cycle. A computer programme was made to calculate parametrically the individual and combined cycle performances, namely the work and efficiency of each. The parameters considered were: gas turbine pressure ratio; maximum cycle temperature; fluid-air mass ratio; and type of working fluid.This analytical study shows that R113 is the optimum choice because it gives the smallest, hence the most economical, size of turbo-expander. Maximum cycle temperature and pressure ratio are relatively the most important parameters. Economic analysis indicates very good rate of return on investment, related with heat recovery by cogeneration.     

Effect of control modes and turbine cooling on the part load performance in the gas turbine cogeneration system

This work aims to analyse the part load performance in a cogeneration system which consists of a single shaft gas turbine and a heat recovery steam generator. Two distinct part load control modes are considered: the constant air flow and the variable air flow. Meanwhile, the effect of variation in the coolant fraction is evaluated, whose purpose is to maintain the blade temperature as high as possible and thus minimise the coolant consumption. The design point parameters of the heat recovery steam generator are determined by the limiting factors on the part load operation, which are represented by the pinch point temperature difference and the approach temperature difference. It turns out that for both air flow control modes, the variable control of coolant fraction leads to improvement of the gas turbine efficiency, while it reduces the heat recovery potential. On the whole, the variable control of coolant fraction has a favourable effect on the overall fuel economy in the cogeneration system.     

Economic power generation from low-temperature geothermal resources using organic rankine cycle combined with vapour absorption chiller

Power generation with low temperature geothermal resources is not economically viable due to the poor thermal efficiency of organic Rankine cycles (ORC). A novel idea is proposed where a vapour absorption chiller (VAC) can be employed to lower the ORC condensing temperature, thus increasing its power output. This paper presents detailed analysis of a VAC that operates with water-lithium bromide to extract heat from the geothermal brine leaving the ORC vaporizer. The evaporator of the VAC serves as the ORC condenser. A computer program is coded to simulate the combined ORC-VAC performance and compare it with that of the conventional ORC. The results indicate that the ORC-VAC option would render power generation more economical. The organic fluid flow rate in the ORC per unit power output is cut by at least 50% in this case, thus reducing the ORC size and turbine cost. Moreover, even though the ORC-VAC includes more components, the total heat exchange area requirement per unit power output remains practically unchanged.     

The effect of the operating parameters of heat recovery steam generators on combined cycle/sea-water desalination plant performance

Combined gas/steam turbine cycle plants have been proposed for cogeneration of electricity and process steam. Examples are combined-cycle power plants coupled with sea-water desalination, district heating plants, chemical industries, etc. In combined heat and power plants, the gas turbine exhaust heat is utilized through the use of heat recovery steam generators (HRSG's). As a result, these waste heat generators (boilers), whether fired or unfired, control the performance of the combined plant lower side (bottoming cycle). Moreover, any changes made in the HRSG operating parameters (i.e. the pinch point, approach temperature, first and second stage pressures, and mass ratios) can greatly affect the HRSG performance and will eventually affect the overall combined plant performance. This paper presents a method to predict the performance of the heat recovery steam generators (HRSG)/steam bottoming cycle combined with sea-water desalination plant at various steam and exhaust gas conditions.     

基于微燃机的HAT循环变工况性能分析

基于某微燃机构建了HAT循环,研究了其在功率下降(ISO条件)、环境温度变化时的变工况性能,并与简单循环、回热循环和RWI(注水回热)循环的设计工况、变工况性能进行了对比。结果表明, HNI、循环和RWI循环的变工况性能相似且好于简单循环和回热循环。其中,空气湿化程度的调整对于HAT循环变工况性能的稳定性起重要作用。但由于没有设置中冷器,且微燃机循环中可资利用的(火用)较少,HAT循环设计工况和变工况性能相对于其它循环的优势没有得到充分体现。     

燃用低热值煤气的联合循环仿真及热经济分析

本文基于Aspen plus软件对燃用低热值煤气的燃气蒸汽联合循环系统进行了模拟仿真。在该仿真平台上对系统设计工况进行了计算验证。在设计工况下,燃气透平进口温度为1000～1050℃,模拟计算结果为1016.2℃。燃气透平出口温度设计参数为517.2℃,模拟结果为519.2℃。结果表明仿真模型能够准确模拟系统稳态情况的各种工况。本文还运用矩阵模式热经济学的方法对系统设计工况下的（?）流成本进行了计算分析,对系统进行了技术经济评价。燃气轮机和蒸汽轮机电能耗费的能量成本分别为22.2,24.06和16.64$·GJ^-1。     

极端高温环境下空气源热泵冷热水机组制冷实验研究

针对现有空气源热泵冷热水机组高温环境运行效果差、效率低、排气温度过高导致停机等问题,设计一套基于准双级压缩循环理论,以R410A为制冷剂的中压补气型空气源热泵冷热水机组。在50℃极端环境温度下,采用中压补气技术,对系统的制冷性能进行实验研究。结果表明:(1)系统出水温度由10℃增至15℃时,制冷量增加77.28%,EER提高59.02%,系统的制冷量、功率和EER均随出水温度的升高而增加;(2)相较不补气模式,系统排气温度由111.9℃降至106.23℃,制冷量由14.14 kW增至16.05 kW,可有效降低排气温度,提升制冷量,能更好提高系统超高温制冷时的稳定性。     

Energy and Exergy Analysis of an Absorption and Mechanical System for a Dehumidification Unit in a Gelatin Factory

In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liquid desiccant system in an industrial gelatin conveyor dryer. The working fluid is a binary solution of lithium chloride (LiCl) in water. Dry air is used in order to decrease the amount of liquid in the gelatin. Therefore, the environmental air must have its absolute humidity reduced from about 12 g/kg to the project target, which is 5 g/kg. The process is a cycle using an absorption desiccant unit (LiCl in water), where the weak solution absorbs water vapor from the air. In the regenerator, condensation of the solution (desorption) from the moist air occurs. As a result, the steam consumption of the desorber and electrical power used for the vapor compression chiller (with ammonia, NH3, as working fluid) are the primary sources of cost for the factory. To improve the plant’s energy and exergy behaviors, the process is evaluated using a mathematical model of the system processes. In addition, we evaluate the substitution of the vapor compression chiller by an absorption unit (lithium bromide (LiBr) in water). The performance indicators of the compression vapor systems showed the best results. Even when using the condenser’s energy to pre-heat the solution, the installed system proved to be more effective.     

Energy conservation in the refinery by utilizing reformed fuel gas and furnace flue gases

Decrease of fuel supplies and cost increases make it vital for industries, especially energy intensive ones, to consider conserving available sources and convert losses into sources of energy.In this paper, a gas turbine-based cogeneration system is suggested to utilize a refinery's reformer gas in the gas turbine, and furnaces flue gases together with the engine exhaust gases in a heat recovery steam generator, HRSG. This is proposed as an alternative to the currently used system where the gas turbine and the steam generator are used separately. Operating variables comprising compressor pressure ratio and turbine inlet temperature are varied widely to evaluate performance; namely power, SFC, overall efficiency and annual fuel savings at design and off-design loading conditions using a dedicated computer program.Results show that the proposed system offers 100% higher overall efficiency and $5.25 million annual fuel saving for a 12 MW_e gas turbine.     

400MW级IGCC机组变工况性能计算

1引言一个多世纪以来,煤一直是世界上主要的发电燃料,这一趋势将在较长的时间内一直保持下去。对于中国这样一个以煤作为一次能源的国家,这一现象尤为突出。特别是随着全球性能源危机的出现以及环境保护要求的提高,使得洁净煤技术（CCT）受到普遍关注。在众多的洁净煤发电技术中,IGCC技术以其特有的高效率、低污染等特点,被认为是下世纪最有发展前途的洁净煤发电技术之一。鉴于IGCC系统结构与组态非常复杂,涉及煤的气化、净化、燃气轮机、余热锅炉、蒸汽轮机、空气分离等关键技术,因此建立IGCC系统的性能模型,对IGCC机组的…     

新型多能源互补系统的热力经济性分析

本文对SOLRGT系统（一种新型的中低温太阳能与化石燃料互补的动力系统）进行了热力经济性分析。该系统基于化学回热循环,通过中低温太阳能品位的间接提升、与先进燃气轮机的集成,实现中低温太阳能的高效、低成本热功转换以及和化石燃料的综合梯级利用。本文将其与同等输入下的两种单输入发电系统进行对比分析,研究表明：基本工况下,SO...     

给水加热型联合循环的变工况性能

在联合循环改造的各种方案中,给水加热型具有投资少、改动少、耗用优质燃料较少、尤其是简单易行及技术难度小等特点,因此在我国现有的技术经济水平、特别是以煤为主的国情下,有一定应用市场。本文分析比较了多种变工况运行方式的性能及可能出现的问题,并在此基础上提出综合性能较好的运行模式。     

整体煤气化联合循环(IGCC)损分布结构研究

整体煤气化联合循环是一种先进的洁净煤发电技术。本文应用#［1316］分析方法,研究IGCC中七个子系统（空分、气化、净化、压气机、燃烧室、透平、余热锅炉及汽机)的#［1316］损失分布,指出系统中最大#［1316］损失过程为煤气化、燃气轮机燃烧和空分过程。同时,揭示了系统随不同空气整体化和氮气回注的规律。这些研究可以指导下一代IGCC系统的改进     

LNG冷能用于CO_2跨临界朗肯循环和CO_2液化回收

提出了一种利用LNG冷能的新方案。一方面,采用CO2作为工质,利用燃气轮机的排放废气作为高温热源和LNG作为低温冷源来实现CO2的跨临界朗肯循环。由于高低温热源温差较大,循环能够顺利进行;另一方面,从燃气轮机排放的CO2废气在朗肯循环中放出热量后经LNG进一步冷却成液态产品。这样,不但利用了LNG冷能,而且天然气燃烧生成的大部分CO2也得以回收。计算分析了相关参数对跨临界循环特性的影响,包括循环最高温度和压力对系统的比功和火用效率的影响,并分析了回收的液态CO2的质量流量的变化情况。结果表明,这种新的LNG冷能利用方案是一种环境友好的高效方案。     

20MW水冷磁体冷却水系统节能优化设计

针对水冷磁体运行产生的热负荷设计了本水冷系统,该系统在保障磁体稳定运行的前提下,进行了节能优化设计。其中自然分层水蓄冷技术的应用不仅节约占地还可增大蓄水量,而利用峰谷电价差进行夜间蓄冷的方式更可节约运行成本;利用闭式冷却塔在气温较低时取代上游冷水机组的设计也最大程度地节约了电能;此外在运行模式方面,系统可根据不同水冷磁体实验负荷进行灵活转换;在设备选择方面,均采用节能环保的产品,如制冷系数高的冷水机组,传热系数较高的板式换热器等。本系统对MW级以上水冷系统设计具有较好的参考价值。     

燃气轮机合成气燃烧室燃料气加湿实验研究

本文针对一种燃用合成气的40MW级燃气轮机燃烧室,进行了该型燃烧室的全压燃料气蒸汽加湿试验研究,得到了燃烧室在基本负荷下随加湿量变化污染物排放、燃烧室内动态压力、火焰筒壁面温度等重要参数的变化规律,分析了燃料气加湿对燃气轮机总体性能、污染物排放、火焰筒壁温及燃烧稳定性方面的影响,探讨了燃料气加湿对合成气燃烧中Nox生成的机理性作用. 研究表明燃料气加湿是降低燃用合成气的燃气轮机氮氧化物排放的有效方式.