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Low temperature heat storages in CO2 supermarket refrigeration systems

Abstract

Refrigeration systems account for a huge share of supermarkets energy consumption. Commercial refrigeration systems with natural refrigerants are becoming more and more popular, and in particular CO2. Carbon dioxide systems are affected by efficiency and capacity reduction at high ambient temperature, due to the low critical temperature. For this reason, different options have been widely analysed and successfully implemented, such as the use of two-phase ejectors, economised cycles, flooded evaporators, etc. An additional possibility to increase the efficiency is the use of heat storages to shift the power consumption from periods of disadvantageous ambient and boundary conditions, and thus low system-efficiency, to those periods with more favourable conditions. This paper analyses the suitability of different low temperature heat storage concepts to increase the efficiency of CO2 refrigeration systems for supermarkets; in addition it evaluates their possible integration with high efficiency lay-outs intended for hot climates. Case studies of the most promising concepts comprise simulations, which use dynamic models of the storage and consider transient boundary conditions for weather and refrigeration loads.

Category

Academic chapter/article/Conference paper

Client

  • Research Council of Norway (RCN) / 195182
  • Research Council of Norway (RCN) / 244009

Language

English

Author(s)

  • N Fidorra
  • Armin Hafner
  • Silvia Minetto
  • Jack Kohler

Affiliation

  • Technische Universität Braunschweig
  • SINTEF Energy Research / Termisk energi
  • National Research Council

Year

2015

Publisher

International Institute of Refrigeration

Book

Proceedings of the 24th International Congress of Refrigeration

Issue

2015

ISBN

978-2-36215-012-8

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