中国电力 ›› 2018, Vol. 51 ›› Issue (9): 53-58.DOI: 10.11930/j.issn.1004-9649.201706111

• 发电 • 上一篇    下一篇

热电厂供热蒸汽管道㶲效率分析

李建锋1, 高圣溥2, 李燕3, 吕俊复4, 高志宏5   

  1. 1. 中国电力企业联合会, 北京 100761;
    2. 输配电装备及系统安全与新技术国家重点实验室(重庆大学), 重庆 400044;
    3. 中国标准化研究院资源与环境分院, 北京 100088;
    4. 清华大学 热科学与工程教育部重点实验室, 北京 100084;
    5. 国网洛阳供电公司, 河南 洛阳 471026
  • 收稿日期:2017-06-15 修回日期:2018-07-02 出版日期:2018-09-05 发布日期:2018-09-20
  • 作者简介:李建锋(1975-),男,从事发电可靠性、能源清洁利用等方面的管理与研究工作,E-mail:qhlijf@163.com
  • 基金资助:
    “十三五”国家重点研发计划资助项目(2016YFB0600201)。

Exergy Efficiency Analysis of Heating Steam Pipeline for Cogeneration Power Plant

LI Jianfeng1, GAO Shengpu2, LI Yan3, LYU Junfu4, GAO Zhihong5   

  1. 1. China Electricity Council, Beijing 100761, China;
    2. State Key Laboratory of Power Transmission Equipment & System Security and New Technology(Chongqing University), Chongqing 400044, China;
    3. Resource and Environmental Branch, China National Institute of Standardization, Beijing 100088, China;
    4. Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China;
    5. State Grid Luoyang Power Supply Company, Luoyang 471026, China
  • Received:2017-06-15 Revised:2018-07-02 Online:2018-09-05 Published:2018-09-20
  • Supported by:
    This work is supported by Key Project of the National Thirteen-Five Year Research Program of China (No.2016YFB0600201).

摘要: 为了评价长距离输送蒸汽管道的能效水平,提出了采用㶲效率作为管道能效计算的一个重要衡量指标,并建立了管道内蒸汽一维流动模型,对某长度为2 km的蒸汽管道的热效率及㶲效率进行了计算。计算结果表明,在蒸汽流量不变时,随着管道直径的增加,管内蒸汽流速不断降低,管道的压力损失及其热效率也随之降低,但是管道㶲效率先增加后降低,有一最大值。在以管道㶲效率为优先目标设计蒸汽管道时,相比较现有的设计规范,管道内蒸汽压力损失因为流速降低而减少,因此在保证用户用汽压力的情况下汽轮机抽汽压力可以有较大幅度的降低,在抽汽流量为250 t/h时,汽轮机因为抽汽压力降低可额外输出约3 330 kW的电功率。因此,管道内蒸汽流速根据投资成本的大小在0~25 m/s范围内选取更为合理。

关键词: 热电厂, 蒸汽管道, 蒸汽流速, 管道㶲效率, 管道热效率, 供热

Abstract: In order to evaluate the energy efficiency of long-distance steam pipe, the exergy efficiency is proposed as an important evaluating indicator to determine the energy efficiency of the steam pipe. A one-dimensional model for flow through steam pipe is established. And then the thermal efficiency and exergy efficiency of the 2 km-long steam pipe are calculated. The calculation results show that under constant steam flow rate, with the increase of the pipe diameter, the steam flow rate in the pipe as well as the pressure loss and thermal efficiency of the pipe will continuously decrease. However, the exergy efficiency of the pipe will increase at first and then decrease, with a maximum value in between. If exergy efficiency of steam pipelines is prioritized as the design target, compared with the existing design specifications, the steam pressure loss in the pipeline will be reduced as a result of the flow rate decrease. As long as enough steam pressure for the user is ensured, the extraction pressure of the steam turbine is allowed to be reduced substantially. At the extraction flow of 250 t/h, the turbine can output an additional 3330 kW of electrical power due to reduced extraction pressure. Therefore, it is more reasonable to select the steam flow rate in the pipeline within the range of 0~25m/s according to the investment cost.

Key words: cogeneration power plant, steam pipe, steam flow rate, pipe exergy efficiency, pipe thermal efficiency, heating

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