Heat-power decoupling and energy saving of the CHP unit with heat pump based waste heat recovery system

No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2022-07-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
16
1-16
Series
Energy, Volume 250
Abstract
Combined heat and power (CHP) plants are operating under more fluctuating working conditions due to the increasingly inconsistent demands for heat and power and integration of renewable energy. This paper proposes to use an electric heat pump (EHP) to decouple heat and power and save energy by recovering waste heat from the cooling water. The thermodynamic model of the CHP unit under dynamic working conditions is established, and the dynamic EHP model based on an efficiency factor is proposed. The heat-power decoupling and energy-saving potential with different heat and power outputs and the heat pump DH ratio (χHP) are analyzed for a CHP unit as a case study. Absorption heat pump (AHP) and EHP-based waste heat recovery systems are also compared. The results indicate that the heat-power decoupling potential is bigger when χHP and the heat demand are increasing. The energy-saving effect is clearer by increasing the coefficient of performance (COP), χHP, or both. AHP and EHP can help the system obtain a certain level of heat-power decoupling and energy-saving effects, but these effects of the AHP-based system are smaller than that of EHP, especially under the working conditions of high heat demand and low power demand.
Description
Funding Information: This work was supported by the China national key research and development program ? China-Finland intergovernmental cooperation in science and technology innovation (Funding No. 2021YFE0116200) and academy research fellow funding from Academy of Finland (Funding No. 336268 and 334205). Funding Information: This work was supported by the China national key research and development program – China -Finland intergovernmental cooperation in science and technology innovation (Funding No. 2021YFE0116200 ) and academy research fellow funding from Academy of Finland (Funding No. 336268 and 334205 ). Publisher Copyright: © 2022 Elsevier Ltd
Keywords
Absorption heat pump (AHP), Combined heat and power (CHP), Electric heat pump (EHP), Energy saving, Heat-power decoupling, Waste heat recovery
Other note
Citation
Wang, H, Hua, P, Wu, X, Zhang, R, Granlund, K, Li, J, Zhu, Y, Lahdelma, R, Teppo, E & Yu, L 2022, ' Heat-power decoupling and energy saving of the CHP unit with heat pump based waste heat recovery system ', Energy, vol. 250, 123846, pp. 1-16 . https://doi.org/10.1016/j.energy.2022.123846