In this paper, a complete transient simulation model of a solar heating and cooling plant is presented. The system under analysis is based on the coupling of evacuated solar collectors with a single-stage LiBr-H2O absorption chiller. An auxiliary heater, circulation pumps, storage tanks, feedback controller, mixers, diverters, ON/OFF hysteresis controller, single lumped capacitance building and controllers are also included. The simulation was performed using the TRNSYS environment. This software also includes a detailed database with weather parameters for several cities all over the world. The system was simulated using specially designed control strategies and varying the main design variables. In particular, a variable speed pump on the solar collector was implemented, in order to maximize the tank temperature and minimize heat losses. A cost model was also developed in order to calculate operating and capital costs. Then, a case study is presented and discussed, aiming at determining the performance of the system, from both energetic and economic viewpoints, in a specific application. A thermoeconomic objective function was also introduced, and finally a sensitivity analysis was performed, in order to calculate the set of synthesis/design parameters that maximize the global efficiency of the system or the above-mentioned objective function, for the case under analysis. The results of the case study showed that a good selection of the SC area and of the volume of the storage tank TK1 are mandatory: PES is positive in case of high solar field area, the optimal thermo-economic volume of storage tank was found at 75 L/m2. The parametric optimization also showed that it is important to lower the SC and AH set-point temperatures, as much as possible.

Dynamic simulation and parametric optimisation of a solar-assisted heating and cooling system

CALISE, FRANCESCO;DENTICE D'ACCADIA, MASSIMO;VANOLI, RAFFAELE
2010

Abstract

In this paper, a complete transient simulation model of a solar heating and cooling plant is presented. The system under analysis is based on the coupling of evacuated solar collectors with a single-stage LiBr-H2O absorption chiller. An auxiliary heater, circulation pumps, storage tanks, feedback controller, mixers, diverters, ON/OFF hysteresis controller, single lumped capacitance building and controllers are also included. The simulation was performed using the TRNSYS environment. This software also includes a detailed database with weather parameters for several cities all over the world. The system was simulated using specially designed control strategies and varying the main design variables. In particular, a variable speed pump on the solar collector was implemented, in order to maximize the tank temperature and minimize heat losses. A cost model was also developed in order to calculate operating and capital costs. Then, a case study is presented and discussed, aiming at determining the performance of the system, from both energetic and economic viewpoints, in a specific application. A thermoeconomic objective function was also introduced, and finally a sensitivity analysis was performed, in order to calculate the set of synthesis/design parameters that maximize the global efficiency of the system or the above-mentioned objective function, for the case under analysis. The results of the case study showed that a good selection of the SC area and of the volume of the storage tank TK1 are mandatory: PES is positive in case of high solar field area, the optimal thermo-economic volume of storage tank was found at 75 L/m2. The parametric optimization also showed that it is important to lower the SC and AH set-point temperatures, as much as possible.
File in questo prodotto:
File Dimensione Formato  
Paper_Vanoli_2.pdf

non disponibili

Tipologia: Altro materiale allegato
Licenza: Accesso privato/ristretto
Dimensione 6.45 MB
Formato Adobe PDF
6.45 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/364687
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 18
  • ???jsp.display-item.citation.isi??? ND
social impact