Highly reliable thermoelectric cooling apparatus and method

US 6,266,962 B1
Filed: 10/07/1999
Issued: 07/31/2001
Est. Priority Date: 10/07/1999
Status: Expired due to Term

First Claim

Patent Images

1. A thermoelectric cooling apparatus comprising:

a source; and

a thermoelectric cooler coupled to said source, said thermoelectric cooler having an operating state;

wherein said source is configured to provide a signal to said thermoelectric cooler to periodically alter at pre-defined time intervals said operating state of said thermoelectric cooler in response to said signal; and

wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.

View all claims

1 Assignment

Timeline View

Assignment View

0 Petitions

Accused Products

Abstract

Apparatus, method, and signal for sub-ambient cooling using thermoelectric dynamics in conjunction with configurations and activation schemes to maximize the mean time between failure (MTBF) of thermoelectric coolers. In one form, a signal is provided which periodically alters the state of the Peltier devices from an active state to a passive state. During the active state the Peltier device provides maximum cooling and during the passive state the Peltier device minimizes thermal leakage while reducing cooling. Preferable implementations provide multiple signals to thermoelectric arrays such that, for a predetermined time, a first set of the arrays are in the active state while a second set of the arrays are in the passive state to thereby minimize failures and maximize the MTBF of the thermoelectric arrays.

72 Citations

View as Search Results

46 Claims

1. A thermoelectric cooling apparatus comprising:
- a source; and
  
  a thermoelectric cooler coupled to said source, said thermoelectric cooler having an operating state;
  
  wherein said source is configured to provide a signal to said thermoelectric cooler to periodically alter at pre-defined time intervals said operating state of said thermoelectric cooler in response to said signal; and
  
  wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- - 2. The apparatus, as recited in claim 1, wherein said source is configured to provide said signal to said thermoelectric cooler top alter said operating state from an active state to a passive state.
  - 3. The apparatus, as recited in claim 2, wherein said signal, in said active state, has a current defined by the following formula:
    - $\begin{matrix} I_{a} = \frac{αΔ T}{R (\sqrt{1 + Z \overline{T}} - 1)} \\ \begin{matrix} I_{a} = Active current signal state \\ R = Combined resistance of thermoelectric arrays \\ Δ T = Temperature differential across the thermoelectric \\ cooling apparatus \\ Z = Thermoelectric figure of merit \\ α = Seebeck coefficient \\ \overline{T} = Average temperature across the thermoelements . \end{matrix} \end{matrix}$
  - 4. The apparatus, as recited in claim 2, wherein said signal, in said passive state, has a current defined by the following formula:
    - $I_{p} = (\frac{α T_{c}}{R}) (1 - \sqrt{1 - \frac{Δ T}{Δ T_{m ax}}})$
5. The apparatus, as recited in claim 1, wherein said thermoelectric cooler includes at least one thermoelectric element.
6. The apparatus, as recited in claim 1, wherein said thermoelectric cooler includes at least one thermoelectric array.
7. The apparatus, as recited in claim 1, wherein said thermoelectric cooler is a multi-stage thermoelectric cooler.
8. The apparatus, as recited in claim 1, wherein said thermoelectric cooler includes at least one Peltier device.
9. The apparatus, as recited in claim 1, further comprising:
- a second thermoelectric cooler coupled to said source, said second thermoelectric cooler having a second state;
  
  wherein said source is configured to provide a second signal to said second thermoelectric cooler to periodically alter said second state of said second thermoelectric cooler in response to said second signal.
10. The apparatus, as recited in claim 9, wherein said second signal is phase shifted relative to said first signal such that, for a predetermined time, said first thermoelectric cooler is in an active state while said second thermoelectric cooler is in a passive state.
11. The apparatus, as recited in claim 1, further comprising a monitoring circuit associated with said thermoelectric cooler for monitoring operating characteristics of said thermoelectric cooler.
12. The apparatus, as recited in claim 1, wherein said thermoelectric cooling apparatus is associated with a food refrigeration system.
13. The apparatus, as recited in claim 1, wherein said thermoelectric cooling apparatus is associated with a vehicle occupant cooling system.
14. The apparatus, as recited in claim 1, wherein said thermoelectric cooling apparatus is associated with least one integrated circuit device.
15. The apparatus, as recited in claim 1, further comprises at least one microelectromechanical (MEMS) device.

16. A thermoelectric cooling apparatus comprising:
- a source;
  
  a first thermoelectric cooler coupled to said source, said first thermoelectric cooler having a first state; and
  
  a second thermoelectric cooler coupled to said source, said second thermoelectric cooler having a second state;
  
  wherein said source is configured to provide a first signal to said first thermoelectric cooler to periodically alter at pre-defined time intervals said first state of said first thermoelectric cooler in response to said first signal;
  
  wherein said source is configured to provide a second signal to said second thermoelectric cooler to periodically alter at pre-defined time intervals said second state of said second thermoelectric cooler in response to said second signal; and
  
  wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.
- View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
- - 17. The apparatus, as recited in claim 16, wherein said second signal is phase shifted relative to said first signal such that, for a predetermined time, said first thermoelectric cooler is in an active state while said second thermoelectric cooler is in a passive state.
  - 18. The apparatus, as recited in claim 16, further comprising a monitoring circuit associated with said first thermoelectric cooler and said second thermoelectric cooler for monitoring operating characteristics of said first thermoelectric cooler and said second thermoelectric cooler.
  - 19. The apparatus, as recited in claim 16, wherein said source is configured to provide said first signal to said first thermoelectric cooler to alter said first state from an active state to a passive state and said second signal to said second thermoelectric cooler to alter said second state from an active state to a passive state.
  - 20. The apparatus, as recited in claim 19, wherein said first and second signals, in said active state, have a current defined by the following formula:
    - $I_{a} = \frac{αΔ T}{R (\sqrt{1 + Z \overline{T}} - 1)}$
21. The apparatus, as recited in claim 19, wherein said first and second signals, in said passive state, have a current defined by the following formula:
- $I_{p} = (\frac{α T_{c}}{R}) (1 - \sqrt{1 - \frac{Δ T}{Δ T_{m ax}}})$ I_p=Passive current signal state R=Combined resistance of thermoelectric arrays Δ
  
  T=Change in temperature α
  
  =Seebeck coefficient T_c=Temperature of the cold end of the thermoelectric cooling apparatus Δ
  
  T_max=maximum temperature differential across the thermoelectric cooling apparatus Δ
  
  T_max=Maximum change in temperature.
22. The apparatus, as recited in claim 16, wherein said first and second thermoelectric coolers include at least one thermoelectric array.
23. The apparatus, as recited in claim 16, wherein said first and second thermoelectric coolers include at least one thermoelectric element.
24. The apparatus, as recited in claim 16, wherein said first and second thermoelectric coolers are multi-staged thermoelectric coolers.
25. The apparatus, as recited in claim 16, wherein said first and second thermoelectric coolers include at least one Peltier device.
26. The apparatus, as recited in claim 16, wherein said thermoelectric cooling apparatus is associated with a food refrigeration system.
27. The apparatus, as recited in claim 16, wherein said thermoelectric cooling apparatus is associated with a vehicle occupant cooling system.
28. The apparatus, as recited in claim 16, wherein said thermoelectric cooling apparatus is associated with at least one integrated circuit device.
29. The apparatus, as recited in claim 16, further comprises at least one microelectromechanical (MEMS) device.

30. A method of operating a thermoelectric cooling apparatus having a source, a thermoelectric cooler coupled to the source, the thermoelectric cooler having an operating state, comprising the steps of:
- providing a signal to the thermoelectric cooler; and
  
  periodically altering at pre-defined time intervals the operating state of the thermoelectric cooler in response to the signal;
  
  wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.
- View Dependent Claims (31, 32, 33, 34, 35, 36)
- - 31. The method, as recited in claim 30, wherein said source is configured to provide said signal to said thermoelectric cooler to alter the operating state from an active state to a passive state.
  - 32. The method, as recited in claim 31, wherein the signal, in the active state, has a current defined by the following formula:
    - $I_{a} = \frac{αΔ T}{R (\sqrt{1 + Z \overline{T}} - 1)}$
33. The method, as recited in claim 31, wherein said signal, in said passive state, has a current defined by the following formula:
- $I_{p} = (\frac{α T_{c}}{R}) (1 - \sqrt{1 - \frac{Δ T}{Δ T_{m ax}}})$ I_p=Passive current signal state R=Combined resistance of thermoelectric arrays Δ
  
  T=Change in temperature α
  
  =Seebeck coefficient T_c=Temperature of the cold end of the thermoelectric cooling apparatus Δ
  
  T_max=maximum temperature differential across the thermoelectric cooling apparatus.
34. The method, as recited in claim 31, further comprising the steps of:
- including a second thermometric cooler coupled to the source, wherein the second thermoelectric cooler has a second state; and
  
  providing a second signal to periodically alter the second state of the second thermoelectric cooler.
35. The method, as recited in claim 34, wherein said second signal is phase shifted relative to said signal such that, for a predetermined time, said thermoelectric cooler is in an active state while said second thermoelectric cooler is in a passive state.
36. The method, as recited in claim 31, further comprising the step of monitoring the operating characteristics of said thermoelectric cooler.

37. A method of operating a thermoelectric cooling apparatus having a source, a first thermoelectric cooler coupled to the source, wherein the thermoelectric cooler has a first state, a second thermoelectric cooler coupled to the source, wherein the second thermoelectric cooler has a second state, comprising the steps of:
- providing a first signal to the first thermoelectric cooler;
  
  periodically altering at pre-defined time intervals the first state of the first thermoelectric cooler in response to the first signal;
  
  providing a second signal to the second thermoelectric cooler;
  
  periodically altering at pre-defined time intervals the second state of the second thermoelectric cooler in response to the second signal;
  
  wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.
- View Dependent Claims (38, 39, 40, 41, 42)
- - 38. The method, as recited in claim 37, wherein said source is configured to provide said first signal to said first thermoelectric cooler to alter said first state from an active state to a passive state and to provide said second signal to said second thermoelectric cooler to alter said second state from an active state to a passive state.
  - 39. The method, as recited in claim 38, wherein the first and second signals, in the active state, are defined by the following formula:
    - $I_{a} = \frac{αΔ T}{R (\sqrt{1 + Z \overline{T}} - 1)}$
40. The method, as recited in claim 38, wherein said first and second signals, in the passive state, have a current defined by the following formula:
- $I_{p} = (\frac{α T_{c}}{R}) (1 - \sqrt{1 - \frac{Δ T}{Δ T_{m ax}}})$ I_p=Passive current signal state R=Combined resistance of thermoelectric arrays Δ
  
  T=Change in temperature α
  
  =Seebeck coefficient T_c=Temperature of the cold end of the thermoelectric cooling apparatus Δ
  
  T_max=maximum temperature differential across the thermoelectric cooling apparatus.
41. The method, as recited in claim 37, wherein said second signal is phase shifted relative to said signal such that, for a predetermined time, said thermoelectric cooler is in an active state with said second thermoelectric cooler is in a passive state.
42. The method, as recited in claim 37, further comprising the step of monitoring the operating characteristics of said thermoelectric cooler.

43. A signal, propagating in a propagation medium for operating a thermoelectric cooler, for periodically altering at pre-defined time intervals the thermoelectric cooler from a first state to a second state wherein said pre-defined time intervals are selected such that a mean time between failure for the thermoelectric cooling apparatus is substantially maximized.
- View Dependent Claims (44, 45, 46)
- - 44. The signal, as recited in claim 43, wherein said first state is configured to be an active state and said second state is configured to be a passive state.
  - 45. The signal, as recited in claim 43, wherein said signal, in said active state, has a current defined by the following formula:
    - $I_{a} = \frac{αΔ T}{R (\sqrt{1 + Z \overline{T}} - 1)}$ I_a=Active current signal state R=Combined resistance of thermoelectric arrays Δ
      
      T=Temperature differential across the thermoelectric cooling apparatus Z=Thermoelectric figure of merit α
      
      =Seebeck coefficient {overscore (T)}=Average temperature across the thermoelements.
  - 46. The signal, as recited in claim 44, wherein said signal, in said passive state, has a current defined by the following formula:
    - $I_{p} = (\frac{α T_{c}}{R}) (1 - \sqrt{1 - \frac{Δ T}{Δ T_{m ax}}})$ I_p=Passive current signal state R=Combined resistance of thermoelectric arrays Δ
      
      T=Change in temperature α
      
      =Seebeck coefficient T_c=Temperature of the cold end of the thermoelectric cooling apparatus Δ
      
      T_max=maximum temperature differential across the thermoelectric cooling apparatus.

Specification

Resources

Litigation Campaign Assessment

Current Assignee
International Business Machines Corporation
Original Assignee
International Business Machines Corporation
Inventors
Ghoshal, Uttam Shyamalindu
Primary Examiner(s)
McDermott, Corrine
Assistant Examiner(s)
JIANG, CHEN WEN

Application Number

US09/414,334
Time in Patent Office

663 Days
Field of Search

62/37, 62/33, 62/36.1, 62/36.2
US Class Current

62/3.7
CPC Class Codes

F25B 21/02 using Peltier effect; using...

Highly reliable thermoelectric cooling apparatus and method

First Claim

1 Assignment

0 Petitions

Accused Products

Abstract

72 Citations

46 Claims

Specification

Solutions

Use Cases

Quick Links

Highly reliable thermoelectric cooling apparatus and method

First Claim

1 Assignment

Subscription Required

Subscription Required

0 Petitions

Subscription Required

Accused Products

Subscription Required

Abstract

72 Citations

46 Claims

Specification

Subscription Required

Solutions

Use Cases

Quick Links