Transient analysis and energy optimization of solar heating and cooling systems in various configurations

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Solar Energy

DOI:https://doi.org/10.1016/J.SOLENER.2010.01.001· OSTI ID:21305696

Calise, F; Dentice d'Accadia, M; Palombo, A ^[1]

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1. DETEC - University of Naples Federico II, P.le Tecchio 80, 80125 Naples (Italy)

In this paper, a transient simulation model of solar-assisted heating and cooling systems (SHC) is presented. A detailed case study is also discussed, in which three different configurations are considered. In all cases, the SHC system is based on the coupling of evacuated solar collectors with a single-stage LiBr-H{sub 2}O absorption chiller, and a gas-fired boiler is also included for auxiliary heating, only during the winter season. In the first configuration, the cooling capacity of the absorption chiller and the solar collector area are designed on the basis of the maximum cooling load, and an electric chiller is used as the auxiliary cooling system. The second layout is similar to the first one, but, in this case, the absorption chiller and the solar collector area are sized in order to balance only a fraction of the maximum cooling load. Finally, in the third configuration, there is no electric chiller, and the auxiliary gas-fired boiler is also used in summer to feed the absorption chiller, in case of scarce solar irradiation. The simulation model was developed using the TRNSYS software, and included the analysis of the dynamic behaviour of the building in which the SHC systems were supposed to be installed. The building was simulated using a single-lumped capacitance model. An economic model was also developed, in order to assess the operating and capital costs of the systems under analysis. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented, in order to determine the set of the synthesis/design variables that maximize the energy efficiency of each configuration under analysis. The results of the case study were analyzed on monthly and weekly basis, paying special attention to the energy and monetary flows of the standard and optimized configurations. The results are encouraging as for the potential of energy saving. On the contrary, the SHC systems appear still far from the economic profitability: however, this is notoriously true for the great majority of renewable energy systems. (author)

• OSTI ID: 21305696
• Journal Information: Solar Energy, Vol. 84, Issue 3; Other Information: Elsevier Ltd. All rights reserved; ISSN 0038-092X
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
EVACUATED COLLECTORS
SOLAR COOLING SYSTEMS
ABSORPTION
AUXILIARY HEATING
SOLAR HEATING SYSTEMS
CONFIGURATION
LITHIUM BROMIDES
SIMULATION
OPTIMIZATION
TRANSIENTS
CAPITALIZED COST
COOLING LOAD
ENERGY EFFICIENCY
ALGORITHMS
BUILDINGS
WATER
COMPUTER CODES
CAPACITY
COUPLING
DESIGN
ECONOMICS
Absorption chillers
Dynamic simulation