OS6B-6:STUDY OF A SECONDARY REFRIGERATION LOOP USING CO2 HYDRATE SLURRY

Jérémy OIGNETA*, Hong Minh HOANG a, Anthony DELAHAYEA, Laurence FOURNAISONA, and Philippe HABERSCHILLB
aLGPES (EA21), Irstea GPAN, 1 rue Pierre Gilles de Gennes 92761 Antony cedex France bUniversité de Lyon, INSA-Lyon, CETHIL UMR 5008 CNRS, Villeurbanne, 69621, France

    Currently, the refrigeration industry accounts for 8% of the greenhouse gases (GHG) emissions, including the impact of HFC refrigerants. One of the solutions to reduce their impact could be the use of hydrate slurries as secondary refrigerant fluids (Fournaison et al. 2004). Carbone dioxide hydrates have a high melting enthalpy (500 kJ/kgwater), higher than that of ice (333 kJ/kgwater), so they can store and transport an important amount of cold energy, and then improve refrigeration device performances.

    The work performed at Irstea investigates the use of CO2 hydrates slurries as phase change materials in a secondary refrigeration loop. A storage tank was associated to the loop in order to form slurry by subcooling. The knowledge of CO2 mass balance (Marinhas et al. 2007) injected in the system gives the hydrate volume fraction formed in the experimental device. It was previously demonstrated that the slurry has a good flowing behaviour up to a hydrate fraction of 20 % (Jerbi et al. 2013).

    In the present paper, thermal and energy studies were carried out on CO2 hydrate slurry.

    Thermal study was performed using heating tube method applied to a secondary refrigeration loop. Heat transfer coefficients around 3000 W.m-2.K-1 for 18 % of hydrate fraction were observed. Energetic and exergetic balances were also carried out in order to evaluate the efficiency of the system.

    Fournaison L., A. Delahaye, I. Chatti et J.P. Petitet, 2004, Ind. Eng. Chem. Res. 43, 6521-6526.

    Jerbi S., A. Delahaye, J. Oignet, L. Fournaison et P. Haberschill, 2013, Int. J. Refrig.

    Marinhas S., A. Delahaye et L. Fournaison, 2007, Int. J. Refrig. 30, 758-766.