Frost detection method on evaporator in vapour compression systems

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. De...

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Detalles Bibliográficos
Autores: Maldonado, José Miguel, Gracia Cuesta, Alvaro de, Zsembinszki, Gabriel, Moreno Argilés, Pere, Albets Chico, Xavier, González, Miguel Ángel, Cabeza, Luisa F.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10459.1/67708
Acceso en línea:https://doi.org/10.1016/j.ijrefrig.2019.10.023
http://hdl.handle.net/10459.1/67708
Access Level:acceso abierto
Palabra clave:Compression refrigeration system
Defrost cycle
Frost detection
Cooling
Système frigorifique à compression
Cycle de dégivrage
Détection de givre
Refroidissement
Descripción
Sumario: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.