Impacto da cadeia de distribuição na temperatura de materiais biomédicos: desenvolvimento de uma ferramenta de previsão e projeto de condições de transporte

Research output: Types of ThesisMaster's Thesis


The APP (Advanced Products Portugal) is a Portuguese company with more than 15 years of experience, focused on the resolution of critical points of the thermal chain, specifically in the health, pharma and food sectors. The main focus of the company is the development of isothermal systems to maintain the temperature of thermosensitive products during their transportation. To answer the needs of APP, a temperature simulation tool was developed to evaluate the internal thermal behavior of an isothermal system, depending on its characteristics and the product to be transported. The tool development was based on the analytical solution of the 2nd Fourier law for heat transfer under unsteady state conditions, considering all the variables that form an isothermal system. The purpose is to analyze and simulate the package thermal behavior according to the external temperature change. Taking profit of the predictive tool, developed in Matlab, it is possible to analyze and verify which variables influence most the product’s temperature. The mathematical tool was validated experimentally, obtaining values at the central and lateral positions inside the system, using a cubic package with a lateral dimension of 0.25m, filled with water as a model. Using a full factorial design at two levels, among 5 pre-selected variables: dimension of the cubic isothermal package, environment temperature (𝑻∞), package thermal conductivity (k) and thickness (Δ𝒙), and initial temperature of the product (Ti), it was possible to conclude on the parameters that influence the most the product’s temperature. The variables are related to the package properties and the isothermal system external conditions. As response, the required time to reach the limit allowed values, for the lateral or central product temperatures, was evaluated. The variables that have the higher influence on the response are the: dimension, 𝑻∞, k, and Δ𝒙, as well as combined effects of the dimension with 𝑻∞, Δ𝒙 or k, and k with 𝑻∞. The product initial temperature, Ti, does not influence the isothermal system behaviour. The type of heat transfer (natural or forced convection) at the isothermal system surface also influences its performance in keeping the product temperature within limited values. The predictive tool was designed for limited situations and is not able to answer all the APP and its clients needs. However, it is an useful tool to estimate and predict how the isothermal systems respond to influencing variables. Moreover, in future developments it is expected to be improved considering new models that can enhance the accuracy of the predicted results. These new developments will require the use of numerical solutions.
Original languagePortuguese
Awarding Institution
  • Faculty of Biotechnology
  • Silva, Alexandre Nuno Meireles Dias da, Supervisor, External person
  • Silva, Cristina L. M., Co-supervisor
  • Pizarro, Manuel, Co-supervisor, External person
Award date12 Mar 2019
Publication statusPublished - 12 Mar 2019


  • Isothermal systems
  • Distribution chain
  • Heat transfer
  • Predictive tool

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