Thermoelectric refrigeration system control scheme for high efficiency performance

Abstract

Embodiments of the present disclosure relate to controlling multiple Thermoelectric Coolers (TECs) to maintain a set point temperature of a chamber. In one embodiment, a controller receives temperature data corresponding to a temperature of the chamber. Based on the temperature data, the controller selectively controls two or more subsets of the TECs to maintain the temperature of the chamber at a desired set point temperature. In this manner, the controller is enabled to control the TECs such that the TECs operate to efficiently maintain the temperature of the chamber at the set point temperature. In another embodiment, the controller selects one or more control schemes enabled by the controller based on temperature data and a desired performance profile. The controller then independently controls one or more subsets of the TECs according to the selected control scheme(s).

What is claimed is: 
     
         1 . A method of controlling a heat exchanger comprising a plurality of thermoelectric coolers (TECs) to maintain a set point temperature of a chamber, the method comprising:
 receiving temperature data indicative of a temperature of the chamber; and   selectively controlling two or more subsets of TECs in the plurality of TECs based on the temperature of the chamber.   
     
     
         2 . The method of  claim 1 , wherein each subset of TECs includes one or more different TECs from the plurality of TECs. 
     
     
         3 . The method of  claim 1 , wherein each TEC in the plurality of TECs is a thin film thermoelectric device. 
     
     
         4 . The method of  claim 1 , wherein selectively controlling the two or more subsets of TECs based on the temperature of the chamber comprises:
 activating a first subset of TECs from the plurality of TECs when the chamber is within a steady state range including the set point temperature; and   maintaining a second subset of TECs from the plurality of TECs in an inactive state such that each TEC in the second subset of TECs is dormant when the chamber is within the steady state range.   
     
     
         5 . The method of  claim 1 , wherein selectively controlling the two or more subsets of TECs comprises operating each TEC in a first subset of TECs from the plurality of TECs at or near Q COPmax  when the chamber is within a steady state range including the set point temperature. 
     
     
         6 . The method of  claim 5 , wherein selectively controlling the two or more subsets of TECs further comprises:
 determining if the temperature of the chamber exceeds an upper threshold of the steady state range.   
     
     
         7 . The method of  claim 6 , wherein selectively controlling the two or more subsets of TECs further comprises:
 increasing a duty cycle of the first subset of TECs in response to determining that the temperature of the chamber exceeds the upper threshold of the steady state range.   
     
     
         8 . The method of  claim 6 , wherein selectively controlling the two or more subsets of TECs further comprises, in response to determining that the temperature of the chamber exceeds the upper threshold of the steady state range, increasing a current provided to the first subset of TECs. 
     
     
         9 . The method of  claim 6 , wherein selectively controlling the two or more subsets of TECs further comprises, in response to determining that the temperature of the chamber exceeds the upper threshold of the steady state range, activating a second subset of TECs from the plurality of TECs. 
     
     
         10 . The method of  claim 6 , wherein selectively controlling the two or more subsets of TECs further comprises, in response to determining that the temperature of the chamber exceeds the upper threshold of the steady state range:
 activating one or more additional subsets of TECs from the plurality of TECs.   
     
     
         11 . The method of  claim 10 , wherein activating the one or more additional subsets of TECs comprises activating the one or more additional subsets of TECs to operate at Q COPmax . 
     
     
         12 . The method of  claim 11 , wherein activating the one or more additional subsets of TECs further comprises increasing a capacity of the one or more additional subsets of TECs from Q COPmax  to a value up to or equal to Q max . 
     
     
         13 . The method of  claim 1 , wherein the heat exchanger further includes a second plurality of TECs, and the method further comprises:
 selectively controlling two or more subsets of TECs in the second plurality of TECs independently of the two or more subsets of TECs in the plurality of TECs.   
     
     
         14 . The method of  claim 13 , wherein selectively controlling the two or more subsets of TECs in the second plurality of TECs comprises:
 activating at least one of the two or more subsets of TECs in the second plurality of TECs when the temperature of the chamber exceeds an upper threshold of a steady state range including the set point temperature.   
     
     
         15 . The method of  claim 1 , wherein selectively controlling the two or more subsets of TECs comprises:
 determining if the temperature of the chamber is less than a lower threshold of a steady state range including the set point temperature.   
     
     
         16 . The method of  claim 15 , wherein selectively controlling the two or more subsets of TECs further comprises:
 decreasing a current provided to at least one subset of the two or more subsets of TECs in response to determining that the temperature of the chamber is less than the lower threshold of the steady state range.   
     
     
         17 . The method of  claim 1 , wherein selectively controlling the two or more subsets of TECs comprises:
 determining if the temperature of the chamber exceeds a maximum allowable temperature for the chamber.   
     
     
         18 . The method of  claim 17 , wherein selectively controlling the two or more subsets of TECs further comprises:
 determining if a temperature at a reject side of the heat exchanger exceeds a maximum allowable temperature for the reject side of the heat exchanger.   
     
     
         19 . The method of  claim 18 , wherein selectively controlling the two or more subsets of TECs further comprises:
 decreasing a current provided to at least one of the two or more subsets of TECs when the temperature of the chamber exceeds the maximum allowable temperature for the chamber and the temperature at the reject side of the heat exchanger exceeds the maximum allowable temperature for the reject side of the heat exchanger.   
     
     
         20 . The method of  claim 18 , wherein selectively controlling the two or more subsets of TECs further comprises:
 deactivating at least one of the two or more subsets of TECs when the temperature of the chamber exceeds the maximum allowable temperature for the chamber and the temperature at the reject side of the heat exchanger exceeds the maximum allowable temperature for the reject side of the heat exchanger.   
     
     
         21 . The method of  claim 18 , wherein selectively controlling the two or more subsets of TECs further comprises, in response to determining that the temperature of the chamber is above the maximum allowable temperature for the chamber and determining that the temperature at the reject side of the heat exchanger is below the maximum allowable temperature for the reject side of the heat exchanger:
 increasing a current provided to at least one of the two or more subsets of TECs up to I max ; and   activating at least one subset of the two or more subsets of TECs that was previously deactivated.   
     
     
         22 . The method of  claim 21 , wherein activating the at least one subset of the two or more subsets of TECs providing the current, up to I max , to the at least one subset of the two or more subsets of TECs. 
     
     
         23 . The method of  claim 1 , further comprising:
 determining that a temperature at a reject side of the heat exchanger exceeds a maximum allowable temperature for the reject side of the heat exchanger;   wherein selectively controlling the two or more subsets of TECs comprises controlling the two or more subsets of TECs to reduce the temperature at the reject side of the heat exchanger in response to determining that the temperature at the reject side of the heat exchanger exceeds the maximum allowable temperature for the reject side of the heat exchanger.   
     
     
         24 . The method of  claim 23 , wherein controlling the two or more subsets of TECs to reduce the temperature at the reject side of the heat exchanger comprises:
 deactivating at least one of the two or more subsets of TECs.   
     
     
         25 . The method of  claim 1 , wherein the chamber is a cooling chamber. 
     
     
         26 . A system comprising:
 a plurality of thermoelectric coolers (TECs); and   a controller associated with the plurality of TECs, the controller configured to:
 receive temperature data indicative of a temperature of a chamber; and 
 selectively control two or more subsets of TECs in the plurality of TECs based on the temperature of the chamber. 
   
     
     
         27 . A system comprising:
 a heat exchanger comprising a plurality of thermoelectric coolers (TECs);   a controller associated with the plurality of TECs configured to:
 select one or more control schemes from a set of control schemes of the controller based on temperature data and a desired performance profile, the set of control schemes comprising two or more of a group consisting of: independently controlling activation and deactivation of each subset of TECs of one or more subsets of TECs in the plurality of TECs, independently controlling a current provided to each subset of TECs of the one or more subsets of TECs in the plurality of TECs, and independently controlling a duty cycle of each subset of TECs of the one or more subsets of TECs in the plurality of TECs; and 
 control the one or more subsets of TECs in the plurality of TECs according to the one or more control schemes selected from the set of control schemes of the controller. 
   
     
     
         28 . The system of  claim 27 , wherein the temperature data comprises a temperature of a cooling chamber associated with the heat exchanger. 
     
     
         29 . The system of  claim 27 , wherein the one or more control schemes selected from the set of control schemes comprise the control scheme of independently controlling the activation and deactivation of each subset of TECs, and the controller is further configured to:
 activate at least one subset of TECs in the one or more subsets of TECs and deactivate at least one subset of TECs in the one or more subsets of TECs for a steady state mode of operation.   
     
     
         30 . The system of  claim 29 , wherein the controller is further configured to, for a recovery mode of operation:
 activate one or more of the at least one subset of TECs deactivated for the steady state mode of operation.   
     
     
         31 . The system of  claim 27 , wherein the one or more control schemes selected from the set of control schemes comprise the control scheme of independently controlling the current provided to each subset of TECs, and the controller is further configured to:
 control the current provided to at least one subset of TECs to be approximately I COPmax  for a steady state mode of operation.   
     
     
         32 . The system of  claim 31 , wherein the controller is further configured to, for a recovery mode of operation:
 increase the current provided to the at least one subset of TECs deactivated for the steady state mode of operation.   
     
     
         33 . The system of  claim 27 , wherein the one or more control schemes selected from the set of control schemes comprise the control scheme of independently controlling the activation and deactivation of each subset of TECs and the control scheme of independently controlling the current provided to each subset of TECs, and the controller is further configured to:
 activate at least one subset of TECs in the one or more subsets of TECs and deactivate at least one subset of TECs in the one or more subsets of TECs for a steady state mode operation; and   control the current provided to the at least one subset of TECs to be approximately I COPmax  for the steady state mode of operation.   
     
     
         34 . The system of  claim 33 , wherein the controller is further configured to, for a recovery mode of operation:
 activate one or more of the at least one subset of TECs deactivated for the steady state mode of operation; and   control the current provided to the one or more of the at least one subset of TECs deactivated for the steady state mode of operation to be in a range of and including approximately I COPmax  to I max .   
     
     
         35 . The system of  claim 27 , wherein the one or more control schemes selected from the set of control schemes comprise the control scheme of independently controlling the duty cycle of each subset of TECs, and the controller is further configured to:
 control the duty cycle of at least one subset of TECs for a steady state mode of operation.   
     
     
         36 . The system of  claim 35 , wherein the controller is further configured to, for a recovery mode of operation:
 increase the duty cycle of the at least one subset of TECs.   
     
     
         37 . The system of  claim 36 , wherein the one or more control schemes selected from the set of control schemes further comprise the control scheme of independently controlling the activation and deactivation of each subset of TECs, and the controller is further configured to, for the recovery mode of operation:
 activate at least one subset of TECs in the one or more subsets of TECs that are deactivated for the steady state mode of operation at a desired duty cycle for the recovery mode of operation.