Techno-economic comparative analysis of innovative combined cycle power plant layouts integrated with heat pumps and thermal energy storageShow others and affiliations
2019 (English)In: Proceedings of the ASME Turbo Expo: Turbomachinery Technical Conference and Exposition, 2019, Vol 3, ASME Press, 2019, Vol. 3Conference paper, Published paper (Refereed)
Abstract [en]
In the pursuit of increasing their profitability, the design and operation of combined cycle power plants needs to be optimized for new liberalized markets with large penetration of renewables. A clear consequence of such renewable integration is the need for these plants for being more flexible in terms of ramping-up periods and higher part-load efficiencies. Flexibility becomes an even clearer need for combined heat and power plants to be more competitive, particularly when simultaneously following the market hourly price dynamics and varying demands for both the heat and the electricity markets. In this paper, three new plant layouts have been investigated by integrating different storage concepts and heat-pump units in key sections of a traditional plant layout. The study analyses the influence that market has on determining the optimum layouts for maximizing profits in energy-only markets (in terms of plant configuration, sizing and operation strategies). The study is performed for a given location nearby Turin, Italy, for which hourly electricity and heat prices, as well as meteorological data, have been gathered. A multi parameter modeling approach was followed using KTH's in house teclmo-economic modeling tool, which uses time dependent market data, e.g. price and weather, to determine the trade-off curves between minimizing investment and maximizing profits when varying critical size-related power plant parameters e.g. installed power capacities and storage size, for pre-defined layouts and operating strategies. A comparative analysis between the best configurations found for each of the proposed layouts and the reference plant is presented in the discussion section of the results. For the specific case study set in northern Italy, it is shown that the integration of a pre-cooling loop into baseload-like power-oriented combined cycle plants is not justified, calling for investigating new markets and different operating strategies. Only the integration of a heat pump alone was shown to improve the profitability, but within the margin of error of the study. Alternatively, a layout where district heating supply water is preheated with a combination of a heat pump with hot thermal tank was able to increase the internal rate of return of the plant by up to 0.5%, absolute, yet within the error margin and thus not justifying the added complexity in operation and in investment costs. All in all, the analysis shows that even when considering energy-only market revenue streams (i.e. heat and electricity sells) the integration of heat pump and storage units could increase the profitability of plants by making them more flexible in terms of power output levels and load variations. The latter is shown true even when excluding other flexibilityrelated revenue streams. It is therefore conclusively suggested to further investigate the proposed layouts in markets with larger heat and power price variations, as well as to investigate the impact of additional control logics and dispatch strategies.
Place, publisher, year, edition, pages
ASME Press, 2019. Vol. 3
National Category
Energy Engineering
Identifiers
URN: urn:nbn:se:kth:diva-266189DOI: 10.1115/GT2019-91036ISI: 000502158200030Scopus ID: 2-s2.0-85075444232OAI: oai:DiVA.org:kth-266189DiVA, id: diva2:1385125
Conference
ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, GT 2019; Phoenix; United States; 17 June 2019 through 21 June 2019
Note
QC 20200113
Part of ISBN 9780791858608
2020-01-132020-01-132024-10-18Bibliographically approved