Exhaust gas recirculation cooler having temperature control

Abstract

A cooling system for cooling a gas flow is provided having a heat exchanger heat exchanger with a plurality of chambers through which a coolant may flow. The system also has a plurality of chamber valves, wherein each of the plurality of chamber valves is configured to selectively control fluid flowing through an associated one of the plurality of chambers. In addition, the system has at least one gas sensor situated to sense a parameter indicative of a temperature of a gas flowing through the heat exchanger. The system further has a controller configured to actuate at least one of the plurality of chamber valves to prevent the flow of coolant through at least one of the plurality of chambers when the gas temperature is below a threshold temperature.

1 . A cooling system for cooling a gas flow, comprising:
 a heat exchanger having a plurality of chambers through which a coolant may flow;   a plurality of chamber valves, each of the plurality of chamber valves being configured to selectively control coolant flowing through an associated one of the plurality of chambers;   at least one gas sensor situated to sense a parameter indicative of a temperature of a gas flowing through the heat exchanger; and   a controller configured to actuate at least one of the plurality of chamber valves to prevent the flow of coolant through at least one of the plurality of chambers when the gas temperature is below a threshold temperature.   
   
   
       2 . The cooling system of  claim 1 , wherein the at least one gas sensor is further configured to sense a parameter indicative of a pressure of gas exiting the heat exchanger. 
   
   
       3 . The cooling system of  claim 2 , wherein the threshold temperature is variable based on the gas pressure. 
   
   
       4 . The cooling system of  claim 3 , wherein the controller is further configured to actuate at least one of the plurality of chamber valves to allow coolant to flow through an associated one of the plurality of chambers that has been previously isolated from the coolant when the gas temperature is above the threshold temperature. 
   
   
       5 . The cooling system of  claim 3 , further including at least one coolant temperature sensor situated to sense a parameter indicative of a temperature of the coolant exiting the heat exchanger and at least one coolant flow rate sensor situated to sense a parameter indicative of a flow rate of the coolant exiting the heat exchanger. 
   
   
       6 . The cooling system of  claim 5 , further including a coolant valve configured to regulate a flow rate of coolant through the heat exchanger. 
   
   
       7 . The cooling system of  claim 5 , wherein the controller is further configured to actuate the coolant valve in response to the temperature and flow rate of coolant exiting the heat exchanger. 
   
   
       8 . The cooling system of  claim 7 , wherein the controller is further configured to actuate the coolant valve to decrease the flow rate of coolant exiting the heat exchanger when the temperature of gas exiting the heat exchanger is below a threshold temperature. 
   
   
       9 . The cooling system of  claim 7 , wherein the controller is further configured to actuate the coolant valve to increase the flow rate of coolant exiting the heat exchanger when the temperature of gas exiting the heat exchanger is above a threshold temperature. 
   
   
       10 . A method for regulating a temperature of a gas, comprising:
 directing a coolant fluid and a gas through a plurality of coolant chambers;   sensing at least one parameter indicative of a temperature of the gas; and   discontinuing a flow of coolant fluid through at least one of the plurality of coolant chambers when the gas temperature is below a threshold temperature.   
   
   
       11 . The method of  claim 10 , further including directing coolant through at least one of the plurality of coolant chambers that has been previously isolated from the flow of coolant when the gas temperature is above a predetermined threshold temperature. 
   
   
       12 . The method of  claim 10 , further including sensing a parameter indicative of at least one of a temperature or a flow rate of the coolant flowing through the plurality of coolant chambers. 
   
   
       13 . The method of  claim 12 , further including adjusting the flow of coolant in response to the gas temperature. 
   
   
       14 . The method of  claim 13 , further including increasing the flow of coolant when the gas temperature is above a predetermined threshold temperature. 
   
   
       15 . The method of  claim 13 , further including decreasing the flow of coolant when the gas temperature is below a predetermined threshold temperature. 
   
   
       16 . A power system, comprising:
 an engine including at least one combustion chamber, an intake manifold, and an exhaust manifold;   an exhaust recirculating valve located downstream of the exhaust manifold and configured to regulate a flow of exhaust gas redirected to the intake manifold of the engine;   a heat exchanger having a plurality of chambers through which an exhaust gas and a coolant may flow;   a plurality of chamber valves, wherein each of the plurality of chamber valves is configured to selectively allow coolant to flow through an associated one of the plurality of chambers and selectively prevent a coolant from flowing through the associated one of the plurality of chambers;   at least one sensor situated to sense a parameter indicative of a temperature of exhaust gas flowing through the heat exchanger;   at least one sensor situated to sense a parameter indicative of a pressure of exhaust gas flowing through the heat exchanger; and   a controller configured to actuate at least one of the plurality of chamber valves to prevent the flow of coolant through at least one of the plurality of chambers when the temperature of the exhaust gas flowing through the heat exchanger is below a threshold temperature that is variable and based on the exhaust gas pressure.   
   
   
       17 . The power system of  claim 16 , wherein the controller is further configured to actuate at least one of the plurality of chamber valves to allow the flow of coolant through an associated one of the plurality of chambers that has been previously isolated from the coolant when the temperature of the exhaust gas flowing through the heat exchanger is above a threshold temperature. 
   
   
       18 . The power system of  claim 16 , further including at least one coolant sensor situated to sense a parameter indicative of at least one of a temperature or a flow rate of coolant flowing through the heat exchanger. 
   
   
       19 . The power system of  claim 18 , wherein the controller is further configured to regulate the flow rate of coolant through the heat exchanger in response to the temperature of coolant flowing through the heat exchanger. 
   
   
       20 . The power system of  claim 19 , wherein the controller is further configured to regulate the flow rate of coolant through the heat exchanger in response to the temperature of exhaust gas flowing through the heat exchanger.