On the consideration of different dead states in the exergy assessment of a solar-assisted combined cooling, heat and power system

Autor: João Victor M. Ferreira, Monica Carvalho, Eduardo José Cidade Cavalcanti
Rok vydání: 2021
Předmět:
Zdroj: Sustainable Energy Technologies and Assessments. 47:101361
ISSN: 2213-1388
DOI: 10.1016/j.seta.2021.101361
Popis: This study focuses on a solar-assisted trigeneration system, designed to meet the electricity, cooling, and heat demands of a residential consumer center. This is the first study to consider different dead state temperatures in the exergy assessment (10–30 °C) of a system containing an absorption chiller. Mass, energy and exergy balances were developed, and the exergy model is based on the SPECO methodology. The COP of the absorption system increases with the temperature of the heat source of exhaust gases. The maximum cooling output is 264.15 kW, with a COP of 1.2, when the ratio exhaust gas/hot water is 0.77:1. When increasing the dead state temperature, there is a slight decrease in the exergy efficiency of the engine and solar system. The exergy efficiency of the absorption chiller is 79.75% for a dead state temperature of 10 °C, changing to 3.66% at 15 °C, 8.06% at 20 °C, 12.69% at 25 °C, and finally 17.57% at 30 °C. The behavior of the overall system is similar, and a consequence of the product and fuel definitions employed by SPECO. This analysis of dead state temperatures is useful for exergoeconomic and exergoenvironmental analyses, as it avoids inconsistencies such as negative cost rates or environmental impact rates.
Databáze: OpenAIRE
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