INSPIRES és un centre de recerca de la Universitat de Lleida. Conforma un grup multidisciplinari que posa especial atenció a la recerca al voltant de la millor gestió energètica, l’eficiència, la usabilitat, la seguretat, la computació d’altes prestacions i la resolució i optimització de problemes, entre altres temes. Tot amb nexes comuns, girant al voltant de l’àmbit de la sostenibilitat i la tecnologia. Suposa una unió d’esforços dels diferents centres de recerca que de manera separada tractaven diferents línies i àrees, ara aquests esforços es comparteixen generant sinèrgies.[Més informació].
Browsing Institut Politècnic d’Innovació i Recerca en Sostenibilitat (INSPIRES) by Author "Albets Chico, Xavier"
(Elsevier, 2018) Maldonado, José Miguel; Zsembinszki, Gabriel; Gracia Cuesta, Alvaro de; Moreno Argilés, Pere; Albets Chico, Xavier; González, Miguel Ángel; Cabeza, Luisa F.
Heat removal is the most extended method for food preservation in food manufacturing industry by lowering food temperatures to stop microorganisms growing, which might spoil the product and could cause toxicity. Therefore, walk-in freezers are used for that purpose consuming a relevant part of the energy on service sector. The compression refrigeration system of the walk-in freezers can be blocked by the frost accumulated on the evaporator. For that reason a defrost process, which requires an important part of the energy consumption, has to be launched from time to time. In this paper, the schedule which manages the defrost process is investigated to limit its activation only when it is necessary. Moreover, different fan operation strategies were tested regarding the energy efficiency of the whole refrigeration system. This study has provided a system control strategy both for defrost and fans operation, depending on the frost built up on the evaporator. The control improves the energy performance of the whole refrigeration system.
(Elsevier, 2020) Maldonado, José Miguel; Gracia Cuesta, Alvaro de; Zsembinszki, Gabriel; Moreno Argilés, Pere; Albets Chico, Xavier; González, Miguel Ángel; Cabeza, Luisa F.
To preserve food nutrients, texture, and taste, as well as to prevent its putrefaction, food is frozen and kept at around −20 °C. Refrigerators and freezers are highly energy demand systems which can suf- fer a considerable decrease in operational efficiency due to frost growth on the evaporator. Defrost pro- cesses are launched periodically to avoid the frost built-up, consuming a relevant part of the total energy demand. To control the defrost launching and to improve the energy performance of the refrigeration system an accurate measurement of the frost level is required. Many frost detecting methods are expen- sive, not feasible due to their size, or simply they cannot measure the frost stacking precisely enough to swerve mal-defrost phenomena. This study provides an accurate parameter to indirectly estimate the frost layer built-up on the evaporator. The new parameter called thermal variation easiness (TVE) was experimentally tested and validated by comparison with another frost leveling method, T method, on a walk-in freezer unit. Then the TVE was successfully tested on a multi-cold room refrigeration system, proving its applicability on both walk-in freezers run by remote condensing units and multiple cold rooms fed by a rack of compressors. The novelty of this parameter lays on its capacity to work on refrigeration facilities which are used to feed several walk-in fridges and refrigerated displays in big installations, such as supermarkets.