Evaluación técnica y económica de una cámara dual de refrigerado y deshidratado de fruta basado en bomba de calor.
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Date
2025
Journal Title
Journal ISSN
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Publisher
Universidad de Concepción
Abstract
A nivel mundial cerca de 1.300 millones de toneladas de alimentos son desperdiciados al año, de las cuales las frutas y vegetales presentan el mayor porcentaje de pérdidas siendo estas cercanas al 55% del total producido.
La presente investigación aborda el problema de las pérdidas de alimento en la etapa de producción en campo, enfocándose en una alternativa que permitiera a los pequeños agricultores aumentar la vida útil de los alimentos o disponer de la opción de agregar valor al producto cosechado para su posterior comercialización. Se propone como objetivo general evaluar técnica y económicamente una cámara dual basada en bomba de calor reversible, capaz de alternar entre los modos de secado y refrigeración dentro de un contenedor de 6 𝑚 aislado térmicamente.
Para cumplir dicho objetivo se realiza: (i) un análisis de mercado que justificó la elección de la manzana por su alta demanda como fruta de exportación y su valor agregado como fruta deshidratada; (sii) el desarrollo de un modelo numérico en EES para el proceso de secado y refrigerado que incorpora un compresor de velocidad variable y un by-pass dinámico de recirculación de aire hacia el evaporador, y (iii) la simulación de seis escenarios de secado y dos de refrigeración, seguidos de una evaluación económica sobre los costos de producción obtenidos para cada simulación versus los obtenidos en otras investigaciones y de otras tecnologías de secado.
Los resultados indican que, en el proceso de secado, la bomba de calor alcanza un 𝐶𝑂𝑃 promedio de 2,4-2,7 y un 𝑆𝑀𝐸𝑅 de 1,3-1,6 𝑘𝑔𝑤/𝑘𝑊ℎ, el punto óptimo se obtiene con una temperatura de 50℃ velocidad del aire de 1,1 𝑚/𝑠 y humedad relativa del 40-45%. En el proceso de refrigeración, la potencia requerida es un 35% menor que en secado, confirmando que el diseño y dimensionamiento de la cámara es gobernado por la etapa de deshidratación.
Se compara el valor 𝑆𝑀𝐸𝑅 obtenido en esta investigación con resultados de otras prácticas de secado, a partir de esto se determina que el secado con bomba de calor presenta significativas reducciones en los costos de producción y una mayor eficiencia de secado.
Se lleva a cabo un análisis de sensibilidad del modelo construido en EES para determinar su respuesta frente a diferentes condiciones de entrada en el proceso de secado. Los valores obtenidos concuerdan con lo descrito en la literatura y es coherente con el proceso de secado.
Se concluye que la cámara dual propuesta es técnicamente viable y económicamente atractiva desde el punto de vista de los costos de producción, debido a su alta eficiencia de extracción de agua y el bajo consumo de energía con respecto a tecnologías tradicionales y calidad del producto.
Approximately, on a global scale, 1,3 billion tons of food are wasted each year, with fruits and vegetables accounting for the highest percentage of losses, close to 55% of their total production. This research explores the issue of food loss during the on-farm production stage, focusing on an alternative that allows small-scale farmers to extend the life of their produce or add value to the harvested product for later commercialization. The general objective is to technically and economically evaluate a dual-function chamber based on a reversible heat pump, capable of alternating between drying and refrigeration mode within a thermally insulated 6-meter container. To achieve this objective, the following steps are carried out: (i) a market analysis that supported the selection of apples due to their high demand in Chile as an export fruit and their added value as a dried product; (ii) the development of a numerical model in EES for the drying and refrigeration process, incorporating a variable-speed compressor and a dynamic air recirculation by-pass toward the evaporator; and (iii) the simulation of six drying scenarios and two refrigeration scenarios, followed by an economic assessment comparing the production costs obtained for each simulation with those reported in previous studies and alternative drying technologies. Results indicate that in the drying process, the heat pump achieves an average 𝐶𝑂𝑃 of 2,4 – 2,7 and an 𝑆𝑀𝐸𝑅 of 1,3 – 1,6 𝑘𝑔𝑤/𝑘𝑊ℎ. The optimal condition for the drying process is at a drying temperature of 50 ℃, air velocity of 1,1 𝑚/𝑠, and relative humidity of the air between 40–45%. In refrigeration mode, the power requirement is 35% lower than in drying mode, confirming that the design and sizing of the chamber is governed by the dehydration stage. The 𝑆𝑀𝐸𝑅 values obtained in this study are compared with those from other drying technologies and papers, showing that heat pump drying significantly reduces production costs and increases drying efficiency. A sensitivity analysis was conducted using the EES model to evaluate system performance under varying input conditions. The results matched existing literature and were consistent with typical drying behavior. In conclusion, the proposed dual-function chamber is technically feasible and economically attractive from a production cost perspective, due to its high-water extraction efficiency, low energy consumption compared to traditional technologies, and its ability to deliver high product quality.
Approximately, on a global scale, 1,3 billion tons of food are wasted each year, with fruits and vegetables accounting for the highest percentage of losses, close to 55% of their total production. This research explores the issue of food loss during the on-farm production stage, focusing on an alternative that allows small-scale farmers to extend the life of their produce or add value to the harvested product for later commercialization. The general objective is to technically and economically evaluate a dual-function chamber based on a reversible heat pump, capable of alternating between drying and refrigeration mode within a thermally insulated 6-meter container. To achieve this objective, the following steps are carried out: (i) a market analysis that supported the selection of apples due to their high demand in Chile as an export fruit and their added value as a dried product; (ii) the development of a numerical model in EES for the drying and refrigeration process, incorporating a variable-speed compressor and a dynamic air recirculation by-pass toward the evaporator; and (iii) the simulation of six drying scenarios and two refrigeration scenarios, followed by an economic assessment comparing the production costs obtained for each simulation with those reported in previous studies and alternative drying technologies. Results indicate that in the drying process, the heat pump achieves an average 𝐶𝑂𝑃 of 2,4 – 2,7 and an 𝑆𝑀𝐸𝑅 of 1,3 – 1,6 𝑘𝑔𝑤/𝑘𝑊ℎ. The optimal condition for the drying process is at a drying temperature of 50 ℃, air velocity of 1,1 𝑚/𝑠, and relative humidity of the air between 40–45%. In refrigeration mode, the power requirement is 35% lower than in drying mode, confirming that the design and sizing of the chamber is governed by the dehydration stage. The 𝑆𝑀𝐸𝑅 values obtained in this study are compared with those from other drying technologies and papers, showing that heat pump drying significantly reduces production costs and increases drying efficiency. A sensitivity analysis was conducted using the EES model to evaluate system performance under varying input conditions. The results matched existing literature and were consistent with typical drying behavior. In conclusion, the proposed dual-function chamber is technically feasible and economically attractive from a production cost perspective, due to its high-water extraction efficiency, low energy consumption compared to traditional technologies, and its ability to deliver high product quality.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Mecánico/a.
Keywords
Frutas, Refrigeración, Deshidratación de alimentos