resumo
The performance of commercial zeolites, with and without binder in its formulation (SYLOBEAD (R) MS C 548: 13X with binder; Kostrolith (R) 13XBFK and NaYBFK: 13X and NaY without binder, respectively), for water adsorption heating applications was compared in this work. Accounting for a Box-Behnken design with four factors (time of adsorption and desorption, t(ADS)(+DES); condensation temperature, T-cond; heat source temperature, T-HTF,T-hot; bed thickness, delta) and three levels, a set of 25 simulations per adsorbent was accomplished, and the performance of the adsorption units was evaluated through the coefficient of performance (COP) and the specific heating power (SHP). The results suggested that the presence of the binder in the formulation of 13X does not penalize the zeolite performance significantly, and that NaYBFK is the most promising material. For the latter solid, statistical outcomes were analyzed and insights about their usefulness to optimize the design and operation of adsorption heat pumps are provided. Pareto charts displaying the impact ranking of the factors upon COP and SHP are discussed, and simple equations are provided for the expeditious estimation of both indicators. Such models were utilized to map system performance and to select optimal geometric/operating parameters that meet specific performance requirements.
palavras-chave
THERMAL-ENERGY STORAGE; BINDERLESS ZEOLITE 13X; NUMERICAL INVESTIGATIONS; OPERATING-CONDITIONS; WORKING PAIRS; LOOSE GRAINS; PERFORMANCE; ADSORBENT; CHILLERS; SYSTEMS
categoria
Thermodynamics; Energy & Fuels; Engineering; Mechanics
autores
Pinheiro, JM; Salustio, S; Valente, AA; Silva, CM
nossos autores
Anabela Tavares Aguiar Valente
Investigador Principal
Carlos Manuel Silva
Professor associado
Joana Marcelino Pinheiro
Estudante de doutoramentoagradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. The authors are grateful to Doctoral Program EngIQ, Fundacao para a Ciencia e Tecnologia (FCT) and Bosch Thermotechnology for a PhD grant (PD/BDE/113538/2015) to Joana M. Pinheiro. The authors thank Chemiewerk Bad Kostritz GmbH (CWK) for providing the binderless NaY material (Kostrolith (R) NaYBFK), and for the authorization to use the respective water adsorption isotherms data. Grace is acknowledged for providing the material SYLOBEAD (R) MS C 548 (13X8). The authors thank Professor Vitor Amaral (CICECO, UA) for the measurements of the thermal conductivities of zeolites (supported through the project "Facing the challenges of characterizing novel thermal materials and processes (Heat@UA)", RECI/CTM-CER/0336/2012 co-financed by FEDER, QREN reference COMPETE: FCOMP-01-0124-FEDER-027465).