联合循环机组轴系统配置方案对比

本文从系统投资、运行维护特点、机组灵活性、系统效率等多个角度出发,通过对比单轴与“2 1”多轴联合循环轴系布置方案以及单轴方案中是否配备SSS离合器的方案,较为详细的阐述了影响燃气轮机联合循环电厂轴系布置方案的主要因素,并给出结合我国国情的建议。     

S109FA联合循环机组轴系波动研究与实践

介绍了某联合循环电厂单轴机组轴系低频波动处理过程和对轴系低频波动的研究。实践表明,加强联合循环单轴机组轴系振动的研究,可以将主设备发生损坏的风险降至最低,为同类型机组的安全运行提供借鉴。     

联合循环机组自动同步离合器国产化研制

国内首次完成了联合循环电厂(CCPP)单轴机组用175MW自动同步(SSS)离合器产品的国产化研制。通过对CCPP单轴机组SSS离合器的功能及技术指标进行分析,阐述了SSS离合器的设计理念,介绍了其基本工作原理、低速保护模块设计原理及关键传扭部件强度分析结果。并在国内首次制造了全尺寸产品样机,搭建了专用试验台,开展了全面的SSS离合器功能试验验证,试验结果证明所研制的SSS离合器符合设计指标,满足功能需求,填补了该项技术的国内空白。     

燃气-蒸汽联合循环电站机组配置及选型分析

对联合循环电站燃气轮机选型、蒸汽系统的选择、余热锅炉和汽轮机选型、机组轴系配置、动力岛布置、主要辅助设备的选择等方面进行了分析研究,为联合循环电站的设计和研究方向提供了建议。     

SSS离合器介绍及其故障诊断

SSS离合器技术已广泛应用于联合循环机组,通过介绍SSS离合器的基本结构和工作原理,对某燃气-蒸汽联合循环机组在SSS离合器脱开过程中出现的低压转子惰走速率减慢和润滑油温度急剧升高的问题进行了诊断,分析所得的结论对同类型机组具有一定的借鉴意义。     

SSS离合器动力学特性简介

文章详细介绍了SSS离合器的基本结构及其工作原理,介绍了传统上对带齿轮联轴器的耦合轴系进行动力学分析时采用的两种方法——单轴分析法与整体分析法,同时分析了两种传统方法的不足,并从工程实用的角度出发,将SSS离合器内啮合齿轮简化等效为六个刚度和阻尼系数,最后根据SSS离合器的工作原理提出将其应用到热电联产汽轮机组上具有极大的优越性。     

燃气-蒸汽联合循环机组汽轮机NCB工况切换特性研究

NCB式汽轮机在热电联产机组中得到广泛应用,论文分析研究了某燃气-蒸汽联合循环发电机组工况切换时的特性,结果表明由于切换过程中SSS离合器的啮合或脱开,低压转子轴向位移、轴瓦振动、轴瓦回油温度以及离合器回油温度均发生明显的变化。在工况切换的过程中应密切监视这些参数的变化并采取有效的措施保证机组的安全。所做工作对于指导机组的运行具有重要的工程应用价值。     

新型F级联合循环单轴轴向排汽汽轮机研发

为满足国内联合循环电站建设及用户需求,研发了一种新型配F级燃气轮机的联合循环汽轮机设计方案。该机组采用单轴、轴向排汽低位布置方式,机组结构更加紧凑,土建成本大幅降低;采用最新的高排抽汽方案,有效地解决了联合循环汽轮机机组抽汽供热时内效率偏低的难题,提高了机组效率。     

带有SSS离合器汽轮发电机组轴系振动分析与处理

针对某厂带有SSS离合器的300 MW级“凝汽-抽汽-背压”(NCB)式汽轮机纯凝运行模式下的轴系振动故障,进行了振动矢量计算、轴瓦温度分析和可倾瓦工作原理分析。计算与分析发现,振动是由高中压转子残余不平衡量、轴瓦载荷较轻、轴瓦瓦块调节性能差等多因素导致。提出提高轴瓦载荷、更换轴瓦瓦块并进行现场轴系动平衡的振动处理方案。运行结果表明：与振动处理前相比,高中压转子高压排汽侧支撑瓦的振动波动现象消失;在汽轮机空负荷工况下,高中压转子高压排汽侧支撑瓦X向通频振动由118μm降低至20μm。     

CCPP单轴、F级联合循环机组热电联供技术研究

为适应国内的联合循环市场需求,以上海汽轮机厂(上汽)成熟的单轴、F级联合循环HE型汽轮机机组为母型,提出了全新的高排抽汽方案。通过对机组强度、推力、轴系等方面的分析论证,证明采用高排抽汽方案对单轴机组的安全可靠运行无影响。该单轴高排抽汽方案在最大供热工况下能够满足50%的热电比需求,同时能够满足抽汽压力为1.2~3.0MPa的可调整抽汽要求。单轴热电联供技术方案的应用使得联合循环的总效率提升0.3%左右,土建投资的成本降低上千万元。     

Proposal and analysis of a novel ammonia–water cycle for power and refrigeration cogeneration

Cogeneration has improved sustainability as it can improve the energy utilization efficiency significantly. In this paper, a novel ammonia-water cycle is proposed for the cogeneration of power and refrigeration. In order to meet the different concentration requirements in the cycle heat addition process and the condensation process, a splitting /absorption unit is introduced and integrated with an ammonia–water Rankine cycle and an ammonia refrigeration cycle. This system can be driven by industrial waste heat or a gas turbine flue gas. The cycle performance was evaluated by the exergy efficiency, which is 58% for the base case system (with the turbine inlet parameters of 450 °C/11.1 MPa and the refrigeration temperature below −15 °C). It is found that there are certain split fractions which maximize the exergy efficiency for given basic working fluid concentration. Compared with the conventional separate generation system of power and refrigeration, the cogeneration system has an 18.2% reduction in energy consumption.     

低温热能发电的研究现状和发展趋势

低温热能种类繁多,数量巨大,利用这部分能源意义重大。介绍了低温热能发电技术的研究现状和发展趋势。低温热能发电技术主要应用于太阳能热电、工业余热发电、地热发电、生物质能发电、海洋温差发电等方面。现阶段低温热能发电的研究重点有:工质的热物性和环保性能、循环优化研究;提高低温热能发电效率的研究,包括混合工质循环、Kalina循环、回热、氨吸收式动力制冷循环等;基于有限时间热力学的系统最优控制等方面的研究。     

Performance analysis of cogeneration systems based on micro gas turbine (MGT), organic Rankine cycle and ejector refrigeration cycle

In this paper, the operation performance of three novel kinds of cogeneration systems under design and off-design condition was investigated. The systems are MGT (micro gas turbine) + ORC (organic Rankine cycle) for electricity demand, MGT+ ERC (ejector refrigeration cycle) for electricity and cooling demand, and MGT+ ORC+ ERC for electricity and cooling demand. The effect of 5 different working fluids on cogeneration systems was studied. The results show that under the design condition, when using R600 in the bottoming cycle, the MGT+ ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334, and the MGT+ ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408. For the MGT+ ORC+ ERC system, the total output is between the other two systems, which is 129.3 kW with a thermal efficiency of 0.370. For the effect of different working fluids, R123 is the most suitable working fluid for MGT+ ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ ERC with the maximum cooling capacity, while both R600 and R123 can make MGT+ ORC+ ERC achieve a good comprehensive performance of refrigeration and electricity. The thermal efficiency of three cogeneration systems can be effectively improved under off-design condition because the bottoming cycle can compensate for the power decrease of MGT. The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems (DES).     

Analysis of power and cooling cogeneration using ammonia-water mixture

Development of innovative thermodynamic cycles is important for the efficient utilization of low-temperature heat sources such as solar, geothermal and waste heat sources. This paper presents a parametric analysis of a combined power/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia-water mixture as the working fluid and produces power and cooling simultaneously. This cycle, also known as the Goswami Cycle, can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using solar or geothermal energy. A thermodynamic study of power and cooling cogeneration is presented. The performance of the cycle for a range of boiler pressures, ammonia concentrations and isentropic turbine efficiencies are studied to find out the sensitivities of net work, amount of cooling and effective efficiencies. The roles of rectifier and superheater on the cycle performance are investigated. The cycle heat source temperature is varied between 90-170 °C and the maximum effective first law and exergy efficiencies for an absorber temperature of 30 °C are calculated as 20% and 72%, respectively. The turbine exit quality of the cycle for different boiler exit scenarios shows that turbine exit quality decreases when the absorber temperature decreases.     

Thermodynamic analysis of load-leveling hyper energy converting and utilization system

Load-leveling hyper energy converting and utilization system (LHECUS) is a hybrid cycle which utilizes ammonia–water mixture as the working fluid in a combined power generation and refrigeration cycle. The power generation cycle functions as a Kalina cycle and an absorption refrigeration cycle is combined with it as a bottoming cycle. LHECUS is designed to utilize the waste heat from industry to produce cooling and power simultaneously. The refrigeration effect can be either transported to end-use sectors by means of a solution transportation absorption chiller (STA) as solution concentration difference or stored for demand load leveling.     

低品位热能利用与减缓气候变暖

低品位热能利用受冷源的制约,其可利用能的温度范围较窄,大部分热能作为废热被排放。本文通过新的制冷循环的建立,探索提高低品位热能制冷效率的方法。新的制冷循环以空气或空气中的主要成分为循环工质,由相互连接、相互影响的气动压缩循环子系统、冷量增益循环子系统和低压补冷循环子系统三部分组成。新的制冷循环以低品位热能作为主要能源,电能作为辅助能源,以期达到更高的能效比,从而使制造冷源成为可能。提高低品位热能的利用率,对减缓气候变暖发挥重要作用。     

Development of a combined system based on a PEMFC and hydrogen storage under different conditions equipped with an ejector cooling system

In the current work, thermodynamic examination for cogeneration of electricity and cooling based on a polymer exchange membrane (PEM) fuel cell was carried out. To the waste energy in the fuel cell, an absorption refrigeration unit is employed in two modes with ejector and without ejector. This system includes a PEM-FC, an absorption refrigeration unit, a hydrogen storage tank, an ejector, and an air compressor. The produced thermal energy in the fuel cell is received entirely by a working fluid and is given to the absorption chiller generator. The system simulation was carried out from two perspectives of energy and fuel saving. Findings showed that the energy efficiency of the combined cooling and power (CCP) unit and the CCP system equipped with the ejector (CCP-E) was 63.72% and 78.33%, respectively. It indicated that adding the ejector to the system increases the energy efficiency of the system by 23%. The fuel economy percentages of the CCP system and CCP-E were 44.43% and 45.9%, respectively. The results also showed that adding the ejector in the refrigeration system increases the system performance by up to 44%. The presence of the ejector causes the working fluid flow in the evaporator to increase with the suction of the secondary flow, and the cooling capacity increases significantly. Moreover, with increasing generator and evaporator pressure, the suction ratio of the cooling system equipped with the ejector decreases and increases, respectively.     

Thermodynamic evaluations of solar cooling cogeneration cycle using NaSCN–NH<Subscript>3</Subscript> mixture

The commercial refrigeration and air conditioning consumes more electric power for its operation. The solar vapor absorption refrigeration helps to minimize the electric power usage and it is renewable. Large size of solar collector area is required for producing the standalone power as well as cooling cycle. The integration of power and cooling cycle minimizes the number of components such as heat exchanger, separator and collector area. The main objective of the work is to integrate power and cooling for two outputs with single cycle using NaSCN–NH₃ as working fluid. The advantages of NaSCN–NH₃ are having high pressure and pure ammonia vapor at the exit of the generator. The integrated cycle is made by providing the turbine at the exit of the generator along with superheater. It has three pressures of generator, condensing and sink pressure, which is depending on separator and ambient temperature. At the separator temperature of 150°C with weak solution concentration of 0.30, it produces the cogeneration output of 284.80 kW with cycle and plant thermal efficiency of 0.49 and 0.20 respectively.     

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%。     

Analysis of a combined power and cooling cycle for low‐grade heat sources

This paper presents a parametric analysis of a combined power/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia–water mixture as the working fluid and produces power and refrigeration, while power is the primary goal. This cycle, also known as the Goswami Cycle, can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using low‐temperature sources such as geothermal and solar energy. Optimum operating conditions were found for a range of ammonia concentration in the basic solution, isentropic turbine efficiency and boiler pressure. It is shown that the cycle can be optimized for net work, cooling output, effective first law and exergy efficiencies. The effect of rectification cooling source (external and internal) on the cycle output was investigated, and it was found that an internal rectification cooling source always produces higher efficiencies. When ammonia vapor is superheated after the rectification process, cycle efficiencies increase but cooling output decreases. Copyright © 2010 John Wiley & Sons, Ltd.