Enquête Sur Les Systèmes De Distribution D'air Et La Régulation De L'environnement Thermique Dans Les Installations De Traitement Des Aliments Réfrigérés

Air flow distribution in chilled food facilities plays a critical role not only in maintaining the required food products temperature but also because of its impact on the facility energy consumption and CO2 emissions. This paper presents an investigation of the thermal environment in existing food manufacturing facilities, with different air distribution systems including supply/return diffusers and fabric ducts, by means of both in-situ measurements and 3D CFD simulations. Measurements and CFD simulations showed that the fabric duct provides a better environment in the processing area in terms of even and low air flow if compared to that with the diffusers. Moreover, temperature stratification was identified as a key factor to be improved to reduce the energy use for the space cooling. Further modelling proved that air temperature stratification improves by relocating the fabric ducts at a medium level. This resulted in a temperature gradient increase up to 4.1 °C in the unoccupied zone

Numerical study of air temperature distribution and refrigeration systems coupling for chilled food processing facilities

This paper presents an air temperature distribution and refrigeration system dynamic coupling model to assess the performance of air distribution systems used in chilled food processing areas and its energy consumption impact. The coupling consists of a CFD air flow/temperature distribution system model and a compression refrigeration system model developed in EES integrated in the TRNSYS platform. The model was tested and validated using experimental data collected from a scaled air distribution test rig in an environmental chamber showing a good agreement with the measured data (an hourly energy consumption error up to 5.3 %). The CFD/EES coupling model can be used to design energy efficient cooled air distribution systems capable to maintain the required thermal environment in chilled food processing facilities

Investigation into air distribution systems and thermal environment control in chilled food processing facilities

Air flow distribution in chilled food facilities plays a critical role not only in maintaining the required food products temperature but also because of its impact on the facility energy consumption and CO2 emissions. This paper presents an investigation of the thermal environment in existing food manufacturing facilities, with different air distribution systems including supply/return diffusers and fabric ducts, by means of both in-situ measurements and 3D CFD simulations. Measurements and CFD simulations showed that the fabric duct provides a better environment in the processing area in terms of even and low air flow if compared to that with the diffusers. Moreover, temperature stratification was identified as a key factor to be improved to reduce the energy use for the space cooling. Further modelling proved that air temperature stratification improves by relocating the fabric ducts at a medium level. This resulted in a temperature gradient increase up to 4.1 °C in the unoccupied zone

Experimental investigation and modelling of thermal environment control of air distribution systems for chilled food manufacturing facilities

Chilled food manufacturing facilities in the majority of cases have high ceilings to allow flexibility for the accommodation of different height equipment and manufacturing lines. The facilities are normally cooled by fan coil units located at ceiling level in a similar way to cold rooms, resulting in high velocities, uncomfortable environments for the workers and high energy consumption. To address these issues, this paper investigates the influence of different air distribution arrangements on air velocities and temperatures in a laboratory scale test facility and by means of a CFD model. The objective was to achieve low velocities and uniform temperatures at low level to achieve temperature stratification between floor and ceiling levels to reduce energy consumption. Experimental and CFD modelling results agreed that supplying air at medium level in the space through fabric ducts ‘socks’ could provide temperature stratification of the order of 7 C between floor and ceiling level and energy savings in the region of 9% compared to ceiling mounted fabric ducts and 23% over non-ducted cooling coils mounted at ceiling level.This project was funded by Innovate UK and the RCUK Centre for Sustainable Energy Use in Food Chains through EPSRC grant No: EP/K011820/1. The authors acknowledge the support from Innovate UK, the RCUK energy programme and contributions from the industrial collaborators Bakkavor and Waterloo Air Products PLC