US 8,948,920 B2Granted

Controlling temperature in a refrigerated transport container

AssigneeA.P. Moller-Maersk A/S

InventorsLeijn Johannes Sjerp Lukasse, Poul Kim Madsen, Lars Mou Jessen

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Abstract

Temperature is controlled in a refrigerated transport container comprising a transport volume, a control unit, a cooling space, one or more fans providing air flow through the cooling space, where air passing through the cooling space passes a return air temperature sensor, a cooling unit, and a supply air temperature sensor. Supply air temperature (Tsup) is controlled to bring temperatures in the transport volume within a desired temperature range around a first temperature set point (Tset). The supply air temperature (Tsup) or a time-averaged function thereof is controlled to reach a temperature below the set point (Tset) during a first limited time period; and the supply air temperature (Tsup) is increased during a second limited time period following said first time period, so that the supply air temperature (Tsup) or a time-averaged function thereof at the end of said second time period is within said desired temperature range.

Claims16

Dependent claims

A method of controlling temperature in a refrigerated transport container, the refrigerated transport container comprising at least a transport volume, a control unit, and a cooling space, one or more fans providing an air flow through the cooling space, where air passing through the cooling space passes at least a return air temperature sensor for measuring a return air temperature (Tret), a cooling unit, and a supply air temperature sensor for measuring a supply air temperature (Tsup), wherein the method comprises:

controlling supply air temperature (Tsup) to bring temperatures in the transport volume within a desired temperature range around a first temperature set point (Tset);
controlling the supply air temperature (Tsup) or a time-averaged function thereof to reach a temperature below said first temperature set point (Tset) during a first limited period of time;
increasing the supply air temperature (Tsup) during a second limited period of time following said first period of time, so that the supply air temperature (Tsup) or a time-averaged function thereof at the end of said second period of time is within said desired temperature range;
controlling the supply air temperature (Tsup) or a time-averaged function thereof to a supply air temperature set point (Tset_slave);
setting the supply air temperature set point (Tset_slave) during said first period of time to a value below said first temperature set point (Tset);
and
increasing the supply air temperature set point (Tset_slave) during said second period of time, so that the supply air temperature set point (Tset_slave) at the end of said second period of time is equal to said first temperature set point (Tset).

4 more elements

A system for controlling temperature in a refrigerated transport container, the refrigerated transport container comprising at least a transport volume and a cooling space, one or more fans providing an air flow through the cooling space, where air passing through the cooling space passes at least a return air temperature sensor for measuring a return air temperature (Tret), a cooling unit, and a supply air temperature sensor for measuring a supply air temperature (Tsup), wherein the system comprises a control unit configured to:

control supply air temperature (Tsup) to bring temperatures in the transport volume within a desired temperature range around a first temperature set point (Tset);
control the supply air temperature (Tsup) or a time-averaged function thereof to reach a temperature below said first temperature set point (Tset) during a first limited period of time;
increase the supply air temperature (Tsup) during a second limited period of time following said first period of time, so that the supply air temperature (Tsup) or a time-averaged function thereof at the end of said second period of time is within said desired temperature range;
control the supply air temperature (Tsup) or a time-averaged function thereof to a supply air temperature set point (Tset_slave);
set the supply air temperature set point (Tset_slave) during said first period of time to a value below said first temperature set point (Tset);
and
increase the supply air temperature set point (Tset_slave) during said second period of time, so that the supply air temperature set point (Tset_slave) at the end of said second period of time is equal to said first temperature set point (Tset).

4 more elements

Dependencies are inferred from the claim text.