Cooling system and vehicle with the same

Abstract

A cooling system for cooling a heat source includes a flow channel through which liquid medium cooling the heat source is circulated, and a pump provided on the flow channel for circulating the liquid medium. The flow channel includes a plurality of branches arranged between an upstream side and a downstream side of the heat source in parallel to a distribution direction of the liquid medium. The cooling system further includes a control device for detecting an abnormality occurred in the cooling system by detecting an imbalance among flow rates of the liquid medium flowing through the plurality of branches, respectively.

1 . A cooling system for cooling a heat source, comprising:
 a flow channel through which liquid medium cooling said heat source is circulated; and   a pump provided on said flow channel for circulating said liquid medium,   said flow channel including a plurality of branches arranged between an upstream side and a downstream side of said heat source in parallel to a distribution direction of said liquid medium,   said cooling system further comprising a control device for detecting an abnormality occurred in any of said plurality of branches by detecting an imbalance among flow rates of said liquid medium flowing through said plurality of branches, respectively, and for diagnosing a cause of occurrence of said abnormality based on the state of said cooling system when the imbalance among the flow rates of said liquid medium is detected.   
     
     
         2 . The cooling system according to  claim 1 , wherein said control device diagnoses a cause of occurrence of said abnormality at least based on the speed of said pump when the imbalance among the flow rates of said liquid medium is detected. 
     
     
         3 . The cooling system according to  claim 2 , further comprising a speed sensor for detecting the speed of said pump, wherein
 in the case where the imbalance among the flow rates of said liquid medium is detected, said control device diagnoses that air has entered said flow channel when a first condition that a detection value of said speed sensor obtained when said pump is driven is higher than a control target value is met.   
     
     
         4 . The cooling system according to  claim 3 , further comprising a temperature sensor for detecting the temperature of said liquid medium, wherein
 in the case where said first condition is not met, said control device determines whether or not a second condition that a detection value of said temperature sensor is lower than a predetermined threshold value is met, and when said second condition is met, said control device diagnoses that said flow channel is frozen.   
     
     
         5 . The cooling system according to  claim 4 , wherein in the case where said second condition is met, said control device determines whether or not a flow rate of said flow channel falls within a control range, and when a third condition that the flow rate of said flow channel falls within said control range is met, said control device diagnoses that any of said plurality of branches is frozen. 
     
     
         6 . The cooling system according to  claim 3 , wherein in the case where said first condition is not met, said control device diagnoses that a foreign substance has entered any of said plurality of branches when said second condition is not met. 
     
     
         7 . The cooling system according to  claim 3 , wherein in the case where it is diagnosed that one of air and a foreign substance has entered any of said plurality of branches, said control device temporarily increases the speed of said pump. 
     
     
         8 . The cooling system according to  claim 5 , wherein in the case where it is diagnosed that any of said plurality of branches is frozen, said control device temporarily increases the amount of heat generation of a heat source corresponding to a branch diagnosed as frozen. 
     
     
         9 . The cooling system according to  claim 1 , wherein
 said heat source is a driving device having a motor and an inverter driving said motor,   said cooling system further comprising an element temperature sensor detecting the temperature of a power control element in said inverter, wherein   under a situation where a condition that another driving instruction is not issued to said inverter is satisfied, said control device temporarily causes the power control element in said inverter to generate heat and then reduces heat generation of said power control element to presume the flow rates of said plurality of branches depending on the degree of drop of a detection value of said element temperature sensor, and detects an imbalance among the flow rates of said liquid medium based on presumed values of the flow rates of said plurality of branches.   
     
     
         10 . The cooling system according to  claim 1 , wherein said plurality of branches are configured to have an equal flow rate. 
     
     
         11 . A vehicle comprising:
 a driving device using a motor (MG) as a drive source; and   a cooling system for cooling said driving device,   said cooling system including
 a flow channel through which liquid medium cooling said driving device is circulated, and 
 a pump provided on said flow channel for circulating said liquid medium, 
   said flow channel including a plurality of branches arranged between an upstream side and a downstream side of said heat source in parallel to a distribution direction of said liquid medium and configured to have an equal flow channel area,
 said vehicle further comprising a control device for detecting an abnormality occurred in system any of said plurality of branches by detecting an imbalance among flow rates of said liquid medium flowing through said plurality of branches, respectively, and for diagnosing a cause of occurrence of said abnormality based on the state of said cooling system when the imbalance among the flow rates of said liquid medium is detected.