Method and system for coolant flow control for a prime mover in a vehicle propulsion system

Abstract

A vehicle propulsion system includes a prime mover having a coolant inlet and coolant outlet, a coolant flow controller having a flow control inlet in communication with the prime mover coolant outlet, and a flow control outlet in communication with the prime mover coolant inlet, and a controller that determines a coefficient based upon a power of the prime mover, and that provides a coolant flow command signal to the coolant flow controller based upon the power of the prime mover.

What is claimed is: 
     
         1 . A method for controlling coolant flow for a prime mover in a vehicle propulsion system, the method comprising:
 determining a gain coefficient based upon a power of the prime mover; and   controlling a coolant flow for the prime mover based upon the determined gain coefficient.   
     
     
         2 . The method of  claim 1 , further comprising determining a power of the prime mover. 
     
     
         3 . The method of  claim 1 , wherein determining a gain coefficient comprises looking up a gain coefficient in a table of gain coefficients based upon the power of the prime mover. 
     
     
         4 . The method of  claim 1 , wherein controlling a coolant flow for the prime mover comprises controlling a coolant flow control valve. 
     
     
         5 . The method of  claim 4 , wherein controlling a coolant flow control valve comprises controlling a position of a rotary valve. 
     
     
         6 . The method of  claim 1 , wherein controlling a coolant flow of the prime mover comprises controlling a coolant pump. 
     
     
         7 . The method of  claim 1 , further comprising sensing a temperature associated with the prime mover and wherein controlling a coolant flow for the prime mover is further based upon the sensed temperature. 
     
     
         8 . The method of  claim 1 , wherein controlling a coolant flow for the prime mover is based upon a difference between the sensed temperature and a predetermined target temperature. 
     
     
         9 . A vehicle propulsion system, the system comprising:
 a prime mover having a coolant inlet and a coolant outlet;   a coolant flow controller having a flow control inlet in communication with the prime mover coolant outlet, and a flow control outlet in communication with the prime mover coolant inlet; and   a controller that determines a coefficient based upon a power of the prime mover, and that provides a coolant flow command signal to the coolant flow controller based upon the power of the prime mover.   
     
     
         10 . The system of  claim 9 , wherein the controller further determines a power of the prime mover. 
     
     
         11 . The system of  claim 9 , further comprising a coefficient storage in communication with the controller that stores a table of coefficients each corresponding to a power of the prime mover and wherein the controller determines the coefficient by looking up a coefficient from the table of coefficients that corresponds to a power of the prime mover. 
     
     
         12 . The system of  claim 9 , wherein the coolant flow controller comprises a coolant flow control valve. 
     
     
         13 . The system of  claim 12 , wherein the coolant flow command signal comprises a coolant flow control valve position command signal. 
     
     
         14 . The system of  claim 9 , wherein the coolant flow controller comprises a coolant pump. 
     
     
         15 . The system of  claim 9 , further comprising a temperature sensor that generates a temperature signal representing a temperature associated with the prime mover. 
     
     
         16 . The system of  claim 15 , wherein the coolant flow command signal is further based upon a difference between the temperature signal and a predetermined target temperature.