Cold storage device

An ice-lined cold storage device which is provided with an indication of simulated autonomy,

• in which the ice-lined storage device is a vaccine storage device and comprises:
• a storage compartment adapted to store a payload of vaccines at a controlled temperature;
• an ice-lining configured to absorb heat from the storage compartment;
• and
• a moveable lid of the storage compartment;
• and in which the simulated autonomy is provided using a temperature model which uses data which is specific to the ice-lined cold storage device and by:
• a) detecting an initial ambient temperature, an initial storage compartment temperature and an initial ice-lining temperature of the ice-lined cold storage device;
• b) running a first simulation using the temperature model and using at least the initial ambient temperature, the initial storage compartment temperature and the initial ice-lining temperature to determine a first simulated storage compartment temperature after a first simulation time step;
• c) running one or more subsequent simulations, each subsequent simulation being run using the temperature model and using data created in a previous simulation, to determine a subsequent simulated storage compartment temperature after a subsequent simulation time step;
• d) determining the simulated autonomy of the ice-lined refrigerator using at least one of the subsequent simulated storage compartment temperature(s).

An ice-lined cold storage device which is provided with an indication of simulated autonomy,

• in which the ice-lined storage device is an ice-lined vaccine storage device which comprises:
• a storage compartment adapted to store a payload of vaccines at a controlled temperature;
• an ice-lining configured to absorb heat from the storage compartment;
• and
• a moveable lid of the storage compartment;
• and in which the simulated autonomy is provided using a temperature model which uses data which is specific to the ice-lined cold storage device and by:
• a) detecting an initial ambient temperature, an initial storage compartment temperature and an initial ice-lining temperature of the ice-lined cold storage device;
• b) running a first simulation using the temperature model and using at least the initial ambient temperature, the initial storage compartment temperature and the initial ice-lining temperature to determine a first simulated storage compartment temperature after a first simulation time step;
• c) running one or more subsequent simulations, each subsequent simulation being run using the temperature model and using data created in a previous simulation, to determine a subsequent simulated storage compartment temperature after a subsequent simulation time step;
• d) determining the simulated autonomy of the ice-lined refrigerator using at least one of the subsequent simulated storage compartment temperature(s);
• in which the first simulation comprises:
• using the initial ice-lining temperature to calculate an initial simulated ice-lining energy,
• using the initial storage compartment temperature to calculate an initial simulated storage compartment energy,
• using the initial ambient temperature and the initial ice-lining temperature to calculate, for the first simulation time step, a first simulation flow of energy into the ice-lining from the surroundings of the ice-lined storage device;
• using the initial ambient temperature and the initial storage compartment temperature to calculate, for the first simulation time step, a first simulation flow of energy into the storage compartment from the surroundings of the ice-lined storage device;
• using the initial ice-lining temperature and the initial storage compartment temperature to calculate, for the first simulation time step, a first simulated flow of energy from the storage compartment into the ice-lining;
• using the initial simulated ice-lining energy, the first simulated flow of energy from the storage compartment into the ice-lining and the first simulation flow of energy into the ice-lining from the surroundings of the ice-lined storage device to calculate a first simulated ice-lining energy;
• using the first simulated ice-lining energy to calculate a first simulated ice-lining temperature;
• using the initial storage compartment energy, the first simulated flow of energy from the storage compartment into the ice-lining and the first simulation flow of energy into the storage compartment from the surroundings of the ice-lined storage device to calculate a first simulated storage compartment energy;
• and
• using the first simulated storage compartment energy to calculate a first simulated storage compartment temperature;
• in which at least one of the subsequent simulations comprises:
• using an indication of ambient temperature at the start of the subsequent simulation time step and the simulated ice-lining temperature from an immediately preceding simulation to calculate, for the simulation time step, a subsequent simulation flow of energy into the ice-lining from the surroundings of the ice-lined storage device;
• using an indication of ambient temperature at the start of the subsequent simulation time step and the simulated storage compartment temperature from an immediately preceding simulation to calculate, for the subsequent simulation time step, a subsequent simulation flow of energy into the storage compartment from the surroundings of the ice-lined storage device;
• using the simulated ice-lining temperature from an immediately preceding simulation and the simulated storage compartment temperature from an immediately preceding simulation to calculate, for the simulation time step, a subsequent simulated flow of energy from the storage compartment into the ice-lining;
• using the simulated ice-lining energy from an immediately preceding simulation, the subsequent simulated flow of energy from the storage compartment into the ice-lining and the subsequent simulation flow of energy into the ice-lining from the surroundings of the ice-lined storage device to calculate a subsequent simulated ice-lining energy;
• using the subsequent simulated ice-lining energy to calculate a subsequent simulated ice-lining temperature;
• using the simulated storage compartment energy from an immediately preceding simulation, the subsequent simulated flow of energy from the storage compartment into the ice-lining and the subsequent simulation flow of energy into the storage compartment from the surroundings of the ice-lined storage device to calculate a subsequent simulated storage compartment energy;
• and
• using the subsequent simulated storage compartment energy to calculate a subsequent simulated storage compartment temperature;
• in which the ice-lined storage device further comprises a lid position indicator which provides an indication as to whether the moveable lid of the storage compartment is in an open position or a closed position;
• and
• in which
• determining the simulated storage compartment temperature comprises adjusting the simulated ice-lining energy to account for energy flows during any time periods during which the lid position indicator indicates the moveable lid as being open;
• and in which
• in c) running one or more subsequent simulations, each subsequent simulation being run using the temperature model and using data created in a previous simulation, to determine a subsequent simulated storage compartment temperature after a subsequent simulation time step;
• the using data created in a previous simulation comprises using data indicative of whether the ice-lining is a) entirely in a solid phase, b) a mixture of solid phase and liquid phase, or c) entirely in a liquid phase, to determine the subsequent simulated storage compartment temperature after the subsequent simulation time step.

A method for determining a simulated autonomy of an ice-lined cold storage device, using a temperature model which uses data which is specific to the ice-lined cold storage device,

• in which the ice-lined cold storage device is a vaccine storage device which comprises
• a storage compartment adapted to store a payload of vaccines at a controlled temperature;
• an ice-lining configured to absorb heat from the storage compartment;
• and
• a moveable lid of the storage compartment;
• and in which the method comprises:
• a) detecting an initial ambient temperature, an initial storage compartment temperature and an initial ice-lining temperature of the ice-lined cold storage device;
• b) running a first simulation using the temperature model and using the initial ambient temperature, the initial storage compartment temperature and the initial ice-lining temperature to determine a first simulated storage compartment temperature after a first simulation time step;
• c) running one or more subsequent simulations, each subsequent simulation being run using the temperature model and using data created in a previous simulation, to determine a subsequent simulated storage compartment temperature after a subsequent simulation time step;
• d) determining the simulated autonomy of the ice-lined refrigerator using at least one of the subsequent simulated storage compartment temperature(s).