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A comprehensive thermodynamic analysis of load‐flexible CHP plants using district heating network
Author(s) -
Sun Yang,
Xu Cheng,
Xu Gang,
Zhang Huishuai,
Li Bin,
Yang Yongping
Publication year - 2019
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.4597
Subject(s) - renewable energy , flexibility (engineering) , cogeneration , thermal energy storage , work (physics) , context (archaeology) , process engineering , demand response , environmental science , engineering , electricity , power (physics) , electricity generation , mechanical engineering , thermodynamics , paleontology , statistics , physics , mathematics , electrical engineering , biology
Summary Because of the rapid expansion of intermittent renewable energy, conventional coal‐fired power plants, including combined heat and power (CHP) plants, are required to improve the quick‐response ability to respond the changing demand of the grid. However, the flexibility of CHP plants is not easy to be improved because of the restriction of traditional load variation mechanism. This work presents a comprehensive thermodynamic analysis on the flexibility‐improving scheme using the thermal energy storage (TES) capacity of district heating (DH) network. A typical CHP plant and related DH network were selected as a case study. The flexibility demand under the context of renewables accommodation in the short timescale (counted by minutes) and the operational characteristics of CHP plants were analyzed on the basis of experimental data and thermodynamics. Besides, the influence of heat supply adjustment on heat users' indoor temperature was quantified with a dynamic model, and the thermal inertia of the DH network is discussed. Moreover, a thermodynamic model for the load variation processes simplified with operational characteristics was established to analyze the response ability improvement of CHP plants. Results of the case study show, the scheme can shorten approximately 34% of the response time while almost have no influence on the indoor temperature of heat users.