Thermo-electric heat pump systems
View Patent ↗The invention is directed to an energy efficient thermoelectric heat pump assembly. The thermoelectric heat pump assembly preferably includes two to nine 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 invention 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. Preferably the transport or storage devices are 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 two thermoelectric unit layers capable of active use of the Peltier effect in thermal conduction with the vessel, each thermoelectric unit layer having a cold side and a hot side;
a capacitance spacer block that stores heat and provides a thermal buffer to delay transfer of heat between the stack of at least two thermoelectric unit layers, wherein a first side of the capacitance spacer block is thermally connected to the hot side of a first thermoelectric unit layer and a second side of the capacitance spacer block opposite the first side of the capacitance spacer block is thermally connected to the cold side of a second thermoelectric unit layer, thereby forming a sandwich layer that pumps heat from the first thermoelectric unit layer to the second thermoelectric layer, and wherein the first thermoelectric unit layer is capable of pumping heat at a different rate than the second thermoelectric unit layer;
an energy source operably connected to each of the at least two thermoelectric unit layers, wherein the energy source is suitable to provide a current, the stack of the at least two thermoelectric unit layers being configured so that each individual thermoelectric unit layer has a ratio of input current to maximum available current (I/Imax) of 0.35 or less at a steady-state when heat removal (Q) is about 0 Watts; and
a heat sink associated with a fan assembly and thermally connected at an end of the stack of at least two thermoelectric unit layers opposite the vessel.
2. The thermal protection system of claim 1 , wherein the I/Imax ratio of each individual thermoelectric unit layer is 0.18 or less at a steady-state, when change in temperature (ΔT) of the stack of at least two thermoelectric unit layers at opposing ends of the stack of at least two thermoelectric unit layers is about 40° C. and heat (Q) is about 0 Watts.
3. The thermal protection system of claim 2 , wherein the I/Imax ratio of each individual thermoelectric unit layer is 0.09 or less at a steady-state, when ΔT of the stack of at least two thermoelectric unit layers at opposing ends of the stack of at least two thermoelectric unit layers is about 20° C. and Q is about 0 Watts.
4. The thermal protection system of claim 1 , wherein the temperature sensitive goods comprise: embryos, oocytes, cell cultures, tissue cultures, chondrocytes, nucleic acids, bodily fluids, bovine semen, organs, plant tissues, pharmaceuticals, vaccines, and chemicals.
5. The thermal protection system of claim 1 , wherein the stack of at least two thermoelectric unit layers is configured to operate when a temperature outside the stack of at least two thermoelectric unit layers is in a range of −30° C. to 60° C.
6. The thermal protection system of claim 1 , wherein the capacitance spacer block separates the first thermoelectric unit layer and the second thermoelectric unit layer by a distance of at least 6.35 mm.
7. The thermal protection system of claim 1 , wherein each of the at least two thermoelectric unit layers comprises a two-dimensional surface area comprising side distances between 40-62 mm and 40-62 mm.
8. 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 unit layers in thermal conduction with the vessel and capable of active use of the Peltier effect, each thermoelectric unit layer having a cold side and a hot side; wherein the hot side of the first thermoelectric unit layer is arranged to face the cold side of the second thermoelectric unit layer, and wherein the first thermoelectric unit layer is capable of pumping heat at a different rate than the second thermoelectric unit layer;
an energy source operably connected to each thermoelectric unit layer, wherein the energy source is suitable to provide a current, the stack of at least the first and second thermoelectric unit layers being configured so that each individual thermoelectric unit layer has a ratio of input current to maximum available current (I/Imax) of 0.18 or less at a steady-state when a change in temperature (ΔT) between opposing ends of the stack of at least the first and second thermoelectric unit layers is less than or equal to about 40° C. and heat removal (Q) is about 0 Watts; and
a heat sink associated with a fan assembly and thermally connected to the stack of at least two thermoelectric unit layers opposite the vessel.
9. The thermal protection system of claim 8 , wherein the temperature sensitive goods comprise at least one of: embryos, oocytes, cell cultures, tissue cultures, chondrocytes, nucleic acids, bodily fluids, bovine semen, organs, plant tissues, pharmaceuticals, vaccines, and chemicals.
10. The thermal protection system of claim 8 , wherein the heat sink comprises a capacity in a range of 35 to 45 Watts.
11. The thermal protection system of claim 8 , wherein the heat sink and the stack of at least the first and second thermoelectric unit layers 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.
12. The thermal protection system of claim 8 , wherein the stack of at least the first and second thermoelectric unit layers is configured to minimize a temperature rise or drop on the heat sink at steady-state so that the temperature rise or drop on the heat sink does not exceed 3° C.
13. The thermal protection system of claim 8 , wherein each thermoelectric unit layer comprises a same size and a same heat pumping capability.
14. 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 unit layers in thermal conduction with the vessel and capable of active use of the Peltier effect, each thermoelectric unit layer comprising 3 or more Ohms at 25° C., each thermoelectric unit layer having a cold side and a hot side, wherein the first thermoelectric unit layer is capable of pumping heat at a different than the second thermoelectric unit layer;
a capacitance spacer block suitable for storing heat and providing a delayed thermal reaction time between the at least two thermoelectric unit layers, wherein a first side of the capacitance spacer block is thermally connected to the hot side of a first thermoelectric unit layer and a second side of the capacitance spacer block opposite the first side of the capacitance spacer block is thermally connected to the cold side of a second thermoelectric unit layer, thereby forming a sandwich layer suitable to pump heat from the first thermoelectric unit layer to the second thermoelectric layer;
an energy source operably connected to each thermoelectric unit layer; and
a heat sink thermally connected to the stack of at least two thermoelectric unit layers opposite the vessel.
15. The thermal protection system of claim 14 , wherein the energy source is suitable to provide a current such that when a change in temperature (ΔT) between opposing ends of the stack of at least two thermoelectric unit layers is less than or equal to about 40° C. at a steady-state, the heat removal (Q) is about 0 Watts.
16. The thermal protection system of claim 15 , wherein a ratio of input current to maximum available current (I/Imax) of each individual thermoelectric unit layer is 0.18 or less at steady-state.
17. The thermal protection system of claim 14 , wherein the temperature sensitive goods include at least one of: embryos, oocytes, cell cultures, tissue cultures, chondrocytes, nucleic acids, bodily fluids, bovine semen, organs, plant tissues, pharmaceuticals, vaccines, and chemicals.
18. The thermal protection system of claim 14 , wherein each thermoelectric unit layer comprises at least 127 coupled pairs of thermoelectric units.
19. The thermal protection system of claim 14 , wherein the two or more thermoelectric unit layers comprise a same size and power.
20. The thermal protection system of claim 14 , wherein the energy source comprises at least one battery that is suitable to maintain a selected temperature for the temperature sensitive goods during transport of at least 72 hours, wherein a difference between the selected temperature of the temperature sensitive goods and an ambient temperature is at least 20° C.