Thermo-electric heat pump systems
View Patent ↗The disclosure is directed to an energy efficient thermal protection assembly. The thermal protection assembly can comprise three or more thermoelectric unit layers capable of active use of the Peltier effect; and at least one capacitance spacer block suitable for storing heat and providing a delayed thermal reaction time of the assembly. The capacitance spacer block is thermally connected between the thermoelectric unit layers. The present disclosure further relates to a thermoelectric transport and storage devices for transporting or storing temperature sensitive goods, for example, vaccines, chemicals, biologicals, and other temperature sensitive goods. The transport or storage device can be configured and provide on-board energy storage for sustaining, for multiple days, at a constant-temperature, with an acceptable temperature variation band.
1. A thermal protection system, relating to thermally protecting temperature sensitive goods, comprising:
a vessel configured to contain the temperature sensitive goods;
a stack of at least three thermoelectric modules thermally coupled to the vessel arranged electrically and thermally in series and configured such that each thermoelectric module within the stack simultaneously uses the Peltier effect, wherein the stack of at least three thermoelectric modules comprise a delta T that increases for each thermoelectric module in a first direction along the stack and an amount of heat transferred by the thermoelectric module (Qc) that increases for each thermoelectric module in a second direction opposite the first direction;
an energy source coupled to the stack of at least three thermoelectric modules and configured to provide a current source simultaneously to each of the serially connected thermoelectric modules, thereby causing simultaneous use of the Peltier effect in each of the at least three thermoelectric modules;
a heat sink coupled to the stack of at least three thermoelectric modules opposite the vessel; and
a microcontroller operatively associated with the energy source to direct current from the energy source to the stack of at least three thermoelectric modules.
2. The thermal protection system of claim 1 , wherein the microcontroller defines a setpoint temperature (Tsp) and compares the Tsp to a temperature (Tc) of a container coupled to the stack of at least three thermoelectric modules and activates a simultaneous use of the Peltier effect for a duration to reduce a difference in temperature between the Tsp and Tc.
3. The thermal protection system of claim 2 , wherein the microcontroller is configured to vary a voltage to the thermoelectric modules by varying a pulse-width-modulation (PWM), a pulse-frequency-modulation (PFM), or a thermal capacitance of the thermal protection system.
4. The thermal protection system of claim 2 , wherein:
the Tsp is defined as a range of temperatures; and
the Tsp and Tc are compared with a resolution greater than or equal to 0.0625 degrees Celsius.
5. The thermal protection system of claim 2 , wherein the microcontroller is configured to receive a user defined Tsp.
6. The thermal protection system of claim 1 , wherein each individual thermoelectric module has a ratio of input current to maximum available current (I/Imax) of 0.17 or less at a steady-state when a change in temperature (ΔT) of the thermal protection system between the vessel and the heat sink is about 20° C. and heat removal (Q) is about 0 Watts.
7. A thermal protection system, relating to thermally protecting temperature sensitive goods, comprising:
a vessel configured to contain the temperature sensitive goods;
a stack of at least three thermoelectric modules thermally coupled to the vessel and arranged electrically and thermally in series and configured such that each thermoelectric module within the stack simultaneously uses the Peltier effect, wherein the stack of at least three thermoelectric modules comprise a delta T that increases for each thermoelectric module in a first direction along the stack and an amount of heat transferred by the thermoelectric module (Qc) that increases for each thermoelectric module in a second direction opposite the first direction;
an energy source coupled to the stack of at least three thermoelectric modules and configured to provide a current source simultaneously to each of the serially connected thermoelectric modules, thereby causing simultaneous use of the Peltier effect in each of the at least three thermoelectric modules; and
a heat sink coupled to the stack of at least three thermoelectric modules opposite the vessel.
8. The thermal protection system of claim 7 , wherein each of the thermoelectric modules are substantially identical in at least one of the following aspects: area, footprint, size, material, thermal conductivity, thermal capacity, electrical resistance, or a number of coupled pairs of thermocouples within the thermoelectric module.
9. The thermal protection system of claim 7 , wherein each of the thermoelectric modules includes a same number of thermocouples.
10. The thermal protection system of claim 7 , wherein the stack of at least three thermoelectric modules comprises a thermal conductance greater than 5 watts per meter per degree centigrade.
11. The thermal protection system of claim 7 , wherein the stack of at least three thermoelectric modules is configured to provide temperature control to at least one temperature to within a tolerance of less than about six degrees centigrade.
12. A thermal protection system, relating to thermally protecting temperature sensitive goods, comprising:
a vessel configured to contain the temperature sensitive goods;
a stack of at least two thermoelectric modules coupled to the vessel and arranged electrically and thermally in series and configured such that each thermoelectric module within the stack simultaneously uses the Peltier effect by simultaneously receiving power from an energy source, wherein the stack of at least three thermoelectric modules comprise a delta T that increases for each thermoelectric module in a first direction along the stack and an amount of heat transferred by the thermoelectric module (Qc) that increases for each thermoelectric module in a second direction opposite the first direction; and
a heat sink coupled to the stack of at least two thermoelectric modules opposite the vessel.
13. The thermal protection system of claim 12 , wherein the heat sink and the stack of at least two thermoelectric modules are configured such that at steady-state the heat sink has a temperature that does not exceed 30% of a heat sink maximum temperature rating.
14. The thermal protection system of claim 12 , wherein at least one energy source is operably connected to each thermoelectric module, wherein the energy source is suitable to provide a current, the thermal protection system being configured so that each individual thermoelectric module has a ratio of input current to maximum available current (I/Imax) of 0.17 or less at a steady-state when a change in temperature (ΔT) of the thermal protection system between the vessel and the heat sink is about 20° C. and heat removal (Q) is about 0 Watts.
15. The thermal protection system of claim 14 , wherein each of the thermoelectric modules are substantially identical in at least one of the following aspects: area, footprint, size, material, thermal conductivity, thermal capacity, electrical resistance, or a number of coupled pairs of thermocouples within the thermoelectric module.
16. The thermal protection system of claim 14 , wherein the stack of at least two thermoelectric modules comprises a thermal conductance greater than 10 watts per meter per degree centigrade.
17. The thermal protection system of claim 12 , wherein the stack of at least two thermoelectric modules is configured to provide temperature control to at least one temperature to within a tolerance of less than about fifteen degrees centigrade.
18. A method of safely transporting temperature sensitive goods at a selected temperature profile during transport using the thermal protection system assembly of claim 12 , comprising:
placing the temperature sensitive goods in a thermal isolation chamber within the transportation device, the thermal isolation chamber adapted to thermally isolate the temperature sensitive goods from an outside environment;
coupling the thermal isolation chamber to the stack of at least two thermoelectric modules; and
controlling a temperature of the thermal isolation control system by activating the Peltier effect of the at least two thermoelectric modules.