This paper introduces food quality as a new parameter, together with energy, to determine an optimal cooling time between defrost cycles. A new defrost-on-demand scheme is proposed. It uses a feedback loop consisting of on-line model updating and estimation as well as a model based optimization. This scheme automatically adjusts the time interval between defrost cycles with varying operating co...

Defrosting in supermarket refrigeration systems is normally controlled by a preset time cycle with most display cabinets timed to defrost every 6 hours. It is widely acknowledged that timed defrost may cause a number of unnecessary defrost cycles and this reduces the energy efficiency of refrigeration systems as well as the accuracy of temperature control of the cases. This paper investigates t...

In this paper, a dynamic heat exchanger model that unifies the frosting and defrosting analyses is presented. A novel scheme is proposed to solve the air flow redistribution due to non-uniform frost blockage. Unlike the existing defrost models which separate analysis for tubes and fins, the proposed defrost model unifies the analysis to maintain model consistency. The first-principles based fro...

Süpermarketlerde teşhir tipi plug-in soğutucular yaygın olarak kullanılmaktadır. Bu soğutucularda şebekeye bağlı drenaj sistemi bulunmadığından, biriken defrost suyu PTC rezistans yardımı ile uzaklaştırılmaktadır. rezistansının enerji tüketimi toplam tüketiminin yaklaşık %20’sini oluşturmaktadır. Nihai birincil kaynaklarından karşılandığı düşünüldüğünde; fosil yakıtların azalması ve maliyetleri...

The paper presents a literature review regarding defrosting methods for household refrigeration and heat pumps. covers the period between 2008 2020. A number of 61 papers have been studied. was conducted by dividing defrost into passive active. Passive involve surface coating off-cycle. active reverse cycle, ultrasonic vibration, hot–gas defrost, electric heating hot fluid. Surface vibration ar...

Assets thrive on liquidity but they also enact a freezing of their own, the underlying. How can we undo cold reign asset economy? By turning state practices into basis for pirate tactic de-assetization. De-assetization means over pipes that keep capital circulating; it applying heat to notion everything in world and should be frozen order release more liquid flows cash.

Mycobacteria were isolated from defrost water and tissue of sole (Solea solea), hake (Merluccius merluccius), cod (Gadus morhua), ling (Genypterus blacodes), and monkfish (Lophius piscatorius) on Löwenstein-Jensen medium after incubation at different temperatures. Samples of frozen fish were obtained under sterile conditions inside a refrigeration chamber (-18 to -22 degrees C) in a wholesale m...