PartagerPoints saillants de ICCC2016: les systèmes à faible charge en ammoniac pour la chaîne du froid
Ce résumé se réfère à une communication présentée pendant la conférence internationale de l'IIF sur la chaîne du froid (ICCC2016) qui s'est tenue en Nouvelle Zélande. Celle-ci peut être téléchargée depuis la base de données Fridoc en utilisant le lien fourni à la fin de l'article.
The following summary refer to three papers presented during the IIR International Cold Chain Conference (ICCC2016) which took place on April 7-9 in Auckland, New Zealand. They can all be downloaded from IIR Fridoc database by using the direct link provided at the end of each article. Don't forget to login or register first!
In its presentation*, R. Lamb stresses that the phase-out of ozone depleting refrigerants and increasing legislative pressure on the use of HFC refrigerants has resulted in greater interest in the use of ammonia for temperature controlled storage/distribution and food production worldwide. Ammonia systems have traditionally had large cooling capacities and tonnes of refrigerant charge.
With more end users now considering the switch to ammonia, concerns have been raised over its toxicity and flammability and this has led to the development of low charge solutions for both chill and low temperature applications.
Advances in evaporator technology have enabled reductions in refrigerant charges of more than 30% by moving from pumped circulation to direct expansion operation for large distributed ammonia systems. Further reductions in charge are possible for cold storage applications by moving to smaller, air-cooled packaged solutions located close to the point of cooling. These charge reductions are achieved through elimination of vessels and shorter pipework. Overall operating cost for these air cooled packages is equal or better than that of evaporative solutions, when accounting for water and chemical usage.
For chill and food processing applications, improvements in compressor and fan efficiencies mean that modern ammonia chillers can mitigate the efficiencies associated by using secondary cooling and heat rejection technology. The use of variable speed reciprocating compressor technology helps improve chiller efficiency compared to fixed speed screw compressor designs.
* Lamb R. Modern, low charge ammonia systems for the cold chain.
Direct link to download this article via Fridoc: http://goo.gl/TkNNS0
In its presentation*, R. Lamb stresses that the phase-out of ozone depleting refrigerants and increasing legislative pressure on the use of HFC refrigerants has resulted in greater interest in the use of ammonia for temperature controlled storage/distribution and food production worldwide. Ammonia systems have traditionally had large cooling capacities and tonnes of refrigerant charge.
With more end users now considering the switch to ammonia, concerns have been raised over its toxicity and flammability and this has led to the development of low charge solutions for both chill and low temperature applications.
Advances in evaporator technology have enabled reductions in refrigerant charges of more than 30% by moving from pumped circulation to direct expansion operation for large distributed ammonia systems. Further reductions in charge are possible for cold storage applications by moving to smaller, air-cooled packaged solutions located close to the point of cooling. These charge reductions are achieved through elimination of vessels and shorter pipework. Overall operating cost for these air cooled packages is equal or better than that of evaporative solutions, when accounting for water and chemical usage.
For chill and food processing applications, improvements in compressor and fan efficiencies mean that modern ammonia chillers can mitigate the efficiencies associated by using secondary cooling and heat rejection technology. The use of variable speed reciprocating compressor technology helps improve chiller efficiency compared to fixed speed screw compressor designs.
* Lamb R. Modern, low charge ammonia systems for the cold chain.
Direct link to download this article via Fridoc: http://goo.gl/TkNNS0