Systems and methods to mitigate heat leak back in a thermoelectric refrigeration system
A thermoelectric refrigeration system includes a heat exchanger that includes a cold side heat sink and a hot side heat sink. The thermoelectric refrigeration system also includes a heat exchange loop coupled to one of the cold side heat sink and the hot side heat sink, the heat exchange loop operating according to thermosiphon principles to provide passive two-phase transport of a working fluid through the heat exchange loop. The thermoelectric refrigeration system also includes thermal insulation that thermally insulates the heat exchanger from a cooling chamber of the thermoelectric refrigeration system or an environment that is external to the thermoelectric refrigeration system.
1. A thermoelectric refrigeration system, comprising:
a cooling chamber;
a heat exchanger within a wall of the cooling chamber comprising:
a cold side heat sink;
a hot side heat sink; and
a cartridge comprising:
an interconnect board with a plurality of conductive traces, including a first conductive trace and one or more additional conductive traces where the first conductive trace and the one or more additional conductive traces are such that current through the first conductive trace and the one or more additional conductive traces can be separately controlled; a plurality of openings from a first surface of the interconnect board to a second surface of the interconnect board, including at least one opening from the first surface of the interconnect board to the second surface of the interconnect board through each of the plurality of conductive traces; and
a plurality of thermoelectric coolers disposed between the cold side heat sink and the hot side heat sink being mounted on the interconnect board over a corresponding one of the plurality of openings through the plurality of conductive traces;
a heat accept loop that operates to provide one-way transport of heat from the cooling chamber to the cold side heat sink according to thermosyphon principles;
a heat reject loop that operates to provide one-way transport of heat from the hot side heat sink to an environment that is external to the thermoelectric system according to thermosyphon principles; and
thermal insulation that thermally insulates the heat exchanger from at least one of the group consisting of the cooling chamber of the thermoelectric refrigeration system and the environment that is external to the thermoelectric refrigeration system.
2. The thermoelectric refrigeration system of claim 1 wherein the heat accept loop and the heat reject loop operate as a thermal diode when the heat exchanger is deactivated such that the thermal diode combined with the thermal insulation prevents heat leak back into the cooling chamber when the heat exchanger is deactivated.
3. The thermoelectric refrigeration system of claim 2 wherein the heat accept loop and the heat reject loop operate as a thermal diode when one or more thermoelectric coolers of the plurality of thermoelectric coolers are deactivated such that the thermal diode combined with the thermal insulation prevents heat leak back into the cooling chamber when the one or more thermoelectric coolers are deactivated.
4. The thermoelectric refrigeration system of claim 1 further comprising:
a controller configured to provide duty cycle control of the plurality of thermoelectric coolers;
wherein the heat accept loop and the heat reject loop operate operates as a thermal diode when one or more thermoelectric coolers of the plurality of thermoelectric coolers are deactivated during an off cycle of the duty cycle control such that the thermal diode combined with the thermal insulation prevents heat leak back into the cooling chamber when the one or more thermoelectric coolers are deactivated during the off cycle of the duty cycle control.
5. The thermoelectric refrigeration system of claim 1 wherein the thermal insulation thermally isolates the heat exchanger from both the cooling chamber and the environment that is external to the thermoelectric refrigeration system.
6. The thermoelectric refrigeration system of claim 5 wherein the cold side heat sink of the heat exchanger is mounted to an outside of a wall of the cooling chamber, and the thermal insulation comprises thermal insulation between the cold side heat sink of the heat exchanger and the wall of the cooling chamber.
7. The thermoelectric refrigeration system of claim 6 further comprising:
a controller configured to provide duty cycle control of the plurality of thermoelectric coolers;
wherein the heat accept loop and the heat reject loop operate as thermal diodes when one or more thermoelectric coolers of the plurality of thermoelectric coolers are deactivated during an off cycle of the duty cycle control such that the thermal diodes combined with the thermal insulation prevents heat leak back into the cooling chamber when the one or more thermoelectric coolers are deactivated during the off cycle of the duty cycle control.
8. The thermoelectric refrigeration system of claim 1 wherein the heat exchanger includes at least one additional cold side heat sink.
9. The thermoelectric refrigeration system of claim 8 wherein the heat accept subsystem loop is an accept loop.
10. The thermoelectric refrigeration system of claim 9 further comprising a second accept loop coupled to one of the at least one additional cold side heat sink.
11. The thermoelectric refrigeration system of claim 10 wherein the accept loop and the second accept loop operate as thermal diodes when the heat exchanger is deactivated such that the thermal diodes combined with the thermal insulation prevents heat leak back into the cooling chamber when the heat exchanger is deactivated.
12. The thermoelectric refrigeration system of claim 10 further comprising at least one additional cooling chamber, wherein the second accept loop operates to extract heat from one of the at least one additional cooling chamber.
13. The thermoelectric refrigeration system of claim 12 wherein the heat exchanger is mounted to an outside of a wall of one of the group consisting of the cooling chamber and the at least one additional cooling chamber.
14. The thermoelectric refrigeration system of claim 1 further comprising a controller configured to provide separate control of one or more of the plurality of thermoelectric coolers.
15. The thermoelectric refrigeration system of claim 1 further comprising a controller configured to:
receive temperature data indicative of a temperature of the cooling chamber; and
operate each thermoelectric cooler in a first subset of thermoelectric coolers from the plurality of thermoelectric coolers at or near the point where the coefficient of performance is maximized by providing a current or voltage with amplitude corresponding to the point where the coefficient of performance is maximized when the temperature of the cooling chamber is within a predefined steady state range including a set point temperature.