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• New correlations for Nu number of ethanol ice slurry in a vertical slit channel. • The effect of flow direction on the values of α coefficients was investigated. • For laminar flow, the melting process has a greater effect of on α coefficient. • For turbulent flow, the convection process has a greater effect on α coefficient. • The upward flow, high ice mass fraction increase the αcoefficients. The article concerns the heat transfer process of ethanol ice slurry during downward and upward flow in a vertical slit channel (3x35.8x700 mm) under constant heat flux density conditions. Experimental studies were conducted for three initial concentrations of ethanol (X vai = 10.5 %, 13.2 %, 15.8 %) and mass fractions of ice of 0 ≤ x s ≤ 30 %. For upward flow, heat transfer coefficients were 6–14 % higher than for downward flow. For laminar flow, a greater effect of the melting process was observed, and for turbulent flow, the convection process had a greater effect on heat transfer coefficients. For laminar flow, the heat transfer coefficients of the ice slurry can be 200 % higher than the corresponding values for the carrier fluid. In turbulent flow, the corresponding increase in heat transfer coefficients did not exceed 15 %. For generalised non-Newtonian flow of ice slurry, criterion relationships were proposed for calculating heat transfer coefficients, taking into account the effect of the concentration of the carrier fluid, mass fractions of ice, its melting process, as well as the nature and direction of the flow. [ABSTRACT FROM AUTHOR]

The ice slurry heat transfer process in flow can be described as forced convection heat transfer of a non-Newtonian fluid subject to phase change (melting of ice crystals). This paper looks at the application of the enthalpy-porosity method to the modelling of the melting process occurring during homogenous tube flow of ice slurry. It will discuss experimentally verified results of thermal calculations, including the distribution of temperature values, heat transfer coefficients and changes to the content of solid particles. The results of the calculations apply to the laminar and turbulent flow areas, various initial mass fractions of ice and various tube cross-section shapes. [ABSTRACT FROM AUTHOR]

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Abstract: The paper presents the results of experimental research on heat transfer of ice slurry during its flow through tubes of circular, rectangular and slit cross-sections. Moreover, the work discusses the influence of solid particles, type of motion and cross-section on the changes in the heat transfer coefficient. The analysis presented in the paper allows for an identification of the criterial relations used to calculate the Nusselt number for laminar and turbulent flow, taking into account elements such as phase change, which accompanies the heat transfer process. Ice slurry flow is treated as a generalized flow of a non-Newtonian fluid. [Copyright &y& Elsevier]

This paper looks at entropy generation during ice slurry flow in straight pipes and typical heat exchanger structures used in refrigeration and air-conditioning technology. A dimensionless relationship was proposed to determine the interdependency between flow velocity and the volume fraction of ice, for which the entropy generation rates were at the minimum level in the case of non-adiabatic ice slurry flow. For pipe flow, the correlation between the minimum entropy generation rate and the overall enhancement efficiency was analyzed. As regards heat exchange processes in heat exchangers, the authors analyzed the relationship between the minimum entropy generation rate and the heat exchange surface area and exchanger efficiency. [ABSTRACT FROM AUTHOR]