Portable temperature controlled container
This invention relates to a portable temperature controlled container comprising a body having a storage compartment, an opening to permit access to the storage compartment and an insulated lid. The container comprises a fan, a heat sink and a first thermoelectric device, as well as a first phase change material and a second thermoelectric device in thermal communication with both the first phase change material and the storage compartment. The second thermoelectric device in thermal communication with both the first phase change material and the storage compartment is operable to transfer energy in the form of heat between the storage compartment and the first phase change material. The thermoelectric devices can be Peltier elements.
1. A portable temperature controlled container comprising:
a body having an outer shell, an inner shell and an insulation layer therebetween, the body defining a storage compartment and an opening to permit access to the storage compartment;
an insulated lid selectively covering the opening in the body;
a first thermoelectric device in thermal communication with the storage compartment;
a first phase change material in thermal communication with the first thermoelectric device;
a rechargeable battery;
a temperature sensor operable to measure the temperature inside the storage compartment;
a controller in communication with the first thermoelectric device and the temperature sensor, the controller being operable to control the first thermoelectric device to regulate the temperature inside the storage compartment; and in which
the first thermoelectric device is operable to remove energy in the form of heat from the storage compartment and transfer that energy in the form of heat to the first phase change material; and
in which there is provided a second thermoelectric device controlled by the controller, a heat sink in thermal communication with the second thermoelectric device, an air passageway through the body, means for opening and closing the air passageway through the body, and a fan operable to deliver airflow through the air passageway over the heat sink; and
in which the first thermoelectric device is sandwiched between the storage compartment and the first phase change material and the second thermoelectric device is sandwiched between the first phase change material and the heat sink.
2. The portable temperature controlled container as claimed in claim 1 in which the storage compartment, first thermoelectric device, first phase change material, second thermoelectric device and heat sink are arranged in a stack configuration with the storage compartment located at the top of the stack, the first thermoelectric device located immediately below the storage compartment, the first phase change material located immediately below the first thermoelectric device, the second thermoelectric device located immediately below the first phase change material and the heat sink located immediately below the second thermoelectric device, at the bottom of the stack.
3. The portable temperature controlled container as claimed in claim 1 in which there is provided a heating element controlled by the controller in thermal communication with the storage compartment.
4. The portable temperature controlled container as claimed in claim 1 in which the first phase change material ( 31 ) undergoes a liquid to solid phase transition upon cooling of that phase change material.
5. The portable temperature controlled container as claimed in claim 1 in which the first phase change material has a phase transition temperature of between −2° C. and 8° C.
6. The portable temperature controlled container as claimed in claim 4 in which the first phase change material has a phase transition temperature of 0° C.
7. The portable temperature controlled container as claimed in claim 4 in which the first phase change material is water.
8. The portable temperature controlled container) as claimed in claim 4 in which the first phase change material is a eutectic composition.
9. The portable temperature controlled container as claimed in claim 1 in which the first thermoelectric device is a peltier device.
10. The portable temperature controlled container as claimed in claim 1 in which the insulation layer comprises a vacuum insulation panel.
11. The portable temperature controlled container as claimed in claim 1 in which the insulation layer has a thermal conductivity value of the order of 0.005 W/m·K.
12. The portable temperature controlled container as claimed in claim 1 in which there is provided a heat transfer block intermediate the first phase change material and the first thermoelectric device in thermal communication therewith.
13. The portable temperature controlled container as claimed in claim 1 in which the storage compartment has a volume of between 10 and 20 litres.