Prepared by Roland Duquesne Thermo King Corporation Presented by Ronnie Meechan: GEA Refrigeration Africa

Cool Chain Association Introduction: Ingersoll Rand-Thermo KingGEA Refrigeration Africa Heat sources Some best practices

Ingersoll Rand - Intro • A $13 billion diversified industrial company • Over 57000 employees worldwide • About 100 manufacturing facilities worldwide • Operations in every major geographic region • Strategic brands are #1 or #2 in their markets

Market-leading Brands Comfort and Climate Control Brands

#1 North America display cases #1 North America service provider

#1 Worldwide transport refrigeration

Industrial Brands

#1 Worldwide golf cars

#1 North America air compressors, air tools

#1 US #2 Worldwide Commercial HVAC Equipment Security Brand

#1 North America lock and door hardware

Climate Solutions

GEA Refrigeration Africa

• Total staff complement of ±320 • 12 Branches

Objective of transport refrigeration - Extend storage and shelf life of product - Maintain quality of product - Reduce the rate of decay -Reduce deterioration by micro organisms

REMOVE HEAT

Main Heat sources - Heat infiltration: Heat gain from outside the compartment - Service load:

Heat gain from doors openings, etc…

- Product load:

Heat gain from cargo: respiration, etc…

- Pre-cooling equipment:

Residual heat in the insulation, air in trailer, etc…

- Product Pre-cooling:

Heat in product if not loaded at correct temperature

- Other factors

Heat Infiltration Heat infiltration through the wall of the loading area through convection, Q convection =

k*A*ΔT/L = Kf*A*ΔT

Example of a std insulated trailer at ambient temp of 38c and inside 0c Kf= 0.02/0.0762 A= 166.82 m2 ΔT= (38-0)

Qtot= 1663 watts

Heat due to service load 1) Heat gain/loss due to air exchange with air outside Example doors are left open Qa = (8/b)*V*

Example:

ΔT*D*E*F*A*G std trailer with same ΔT as previously and 10 single door opening of 5 minutes each

Qa= 1788 watts

Heat due to service load 2) Heat residual in the trailer or box if not pre-cooled 3 factors:

Inner lining of body Insulation of body Air in body

Example std trailer parked at 38c ambient -Inner lining: -Insulation: - Air: Total:

2543 watts 624 watts 400 watts 3567 watts

Heat due to service load 2) Product Pre-cooling/Heating To bring a product past the freezing point the heat to be extracted is the sum of Qproduct = Qunfrozen+Qlatent+Qfrozen Heat extracted to bring product to freezing point The latent heat to freeze the product Heat extracted to bring product to its final temperature Example:

a refrigeration compartment with setpoint at +13c is loaded with 3000 kg of mangoes at +30c specific heat of mangos: 3.559J/kg*K Heat need to be extracted in 2 hrs

Qproduct = 3000*3559*23/2= 34107 Watts !!! or with same conditions with a std reefer unit we would need 6 hrs !!!

Heat due to Product Load Product continue to give off heat after harvest = heat of respiration Fruit –vegetables take in oxygen , releasing carbon dioxide and heat (See ethylene slide)

Qr = Mp*R

Example:

a refrigeration compartment with setpoint at +0c is loaded with 3000 kg of strawberries at +0c

Qr = 3000/1000*44.4 = 133 Watts

Heat due to other factors Loading:

- sealed docks?; time to load?

Defrost events:

- capacity of unit used to extract water from the air - loss of capacity due to unit defrosting

Air exchange:

- Air need to circulate properly to avoid hot/cold spots. Air carries the heat to the evaporator to remove the heat from compartment

Product loading:

- pallets, boxes, stacking

Air exchange Make sure air is not restricted Best practices : 6 directions Humidity is not covered in this section

Reminder: Link between ethylene and respiration to be detailled There is a link between internal ethylene and CO2 - respiration There is a minimum of ethylene concentration needed to induct rippening of the fruit The skin of fruit and surface exposed to air influences the ethylene content as well as the release of it. a few hours after harvest fruit already have detectable ethylene quantities. The ethylene content rises when fruit approach the respiratory climate The deterioration peak is when the fruit have softened and changed in colour This process is also directly associated to production of CO2

Reminder: Link between ethylene and CO2 release for mangos

THANK YOU