Simulation of a cooling processes of wort using a immersion chiller

• Autor(a) principal: Brito, Juliano Fernandes Dias Taveira de
• Data de Publicação: 2022
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/50750
• topic: CNPQ::ENGENHARIAS; Cooling process; Heat Transfer; Numerical Simulation

Brewing beer involves many processes that require tight control of temperature. One of the most important occurs right after the boiling of the wort, when rapid cooling is needed to avoid contamination by bacteria and give the beer the right taste. The most common method for cooling the wort used by home-brewers is the pipe coil, since it is cheap, easy to use, and requires minimal maintenance. The pipe coil is immersed in the hot wort, which is contained in a vessel, and cold water flows through the pipe. This paper investigates the heat transfer in such a type of system to predict the water consumption and the time required to cool the wort to the desired temperature, necessary for a better design the cooling system. Three heat transfer processes were taken into account: natural convection between vessel and air, cooling due to wort evaporation, and cooling promoted by the pipe coil. In the last case, they are considered forced internal convection due to the water flow inside the pipe and natural convection between the pipe external surface and the wort. These processes are coupled and were numerically solved using a computer code written in Phyton. The wort temperature changes very slowly as compared to the temperature variation of the water flowing along the pipe. Therefore, in each time step of the simulation, the conditions of the internal flow were assumed to be steady. For the numerical simulation, the pipe can be discretized into several segments along its axial direction. When only a single segment is assumed for the entire pipe, the solution equals the approximated solution presented in the literature for internal forced flow. The result shows that, as expected, a higher flow of water leads to higher heat transfer thus decreasing the time required for cooling with the drawback of more water consumption. More results and factors (such as the cost of the system, for example) need to be obtained to optimize the system design. Finally, it is worth to observe that this type of cooling system is employed in different processes, and therefore the obtained results are expected to be helpful in applications diverse of the considered brewing beer.