Three-way modulating valve for temperature control

Abstract

A temperature sensor for a first fluid senses a temperature of the first fluid downstream of a heat exchanger. A supply for a second fluid changes a temperature of the first fluid. The supply for the second fluid passes through the heat exchanger. A valve is positioned upstream of the said heat exchanger on the supply for the second fluid, and controls a flow rate of the second fluid diverted into a bypass line compared to a flow rate of the second fluid directed through the heat exchanger, with the three-way valve controlled by a control in response to feedback from said temperature sensor. The valve changes the respective flow rates delivered into the bypass line and through the said heat exchanger in a non-linear manner with a change in valve position. A manned spaceship is also disclosed.

1 . A system for changing the temperature of a first fluid to meet a desired temperature comprising:
 a fluid supply for said first fluid, said fluid supply for said first fluid passing through a heat exchanger, and a temperature sensor for said first fluid to sense a temperature of said first fluid downstream of said heat exchanger;   a supply for a second fluid to change a temperature of said first fluid, said supply for said second fluid passing through said heat exchanger;   a valve positioned upstream of said heat exchanger on said supply for said second fluid, and controlling a flow rate of said second fluid diverted into a bypass line compared to a flow rate of said second fluid directed through said heat exchanger, with said three-way valve controlled by a control in response to feedback from said temperature sensor; and   said valve changes the respective flow rates delivered into said bypass line and through said heat exchanger in a non-linear manner with a change in valve position.   
     
     
         2 . The system as set forth in  claim 1 , wherein said second fluid cools said first fluid. 
     
     
         3 . The system as set forth in  claim 2 , wherein said first fluid is air and said second fluid is a cooling fluid for air. 
     
     
         4 . The system as set forth in  claim 3 , wherein said air is to be delivered into an interior of a manned spacecraft. 
     
     
         5 . The system as set forth in  claim 1 , wherein said valve includes a rotating spool with a first window delivering said second fluid into a first outlet leading to said bypass line and a second window delivering fluid into a line leading to said heat exchanger and said valve changing position in a circumferential direction to achieve said non-linear manner of changing the respective flow rates. 
     
     
         6 . The system as set forth in  claim 5 , wherein each of said first and second windows have an enlarged area portion and which change in a non-linear manner when moving in a circumferential direction. 
     
     
         7 . The system as set forth in  claim 5 , wherein said first and second windows are also designed to achieve a change in pressure drop as said valve spool rotates to, in turn, keep a total pressure drop across said system between said valve and said heat exchanger that is relatively close to constant as said valve changes the portion of the second fluid passing through said heat exchanger. 
     
     
         8 . The system as set forth in  claim 7 , wherein said first and second windows are non-symmetric. 
     
     
         9 . The system as set forth in  claim 7 , wherein said first and second windows are symmetric. 
     
     
         10 . The system as set forth in  claim 5 , wherein said first and second windows are non-symmetric. 
     
     
         11 . The system as set forth in  claim 1 , wherein said valve moves axially, and two valve pistons control the respective flow to said bypass line and to said heat exchanger. 
     
     
         12 . The system as set forth in  claim 1 , wherein fluid passages in said valve leading to said bypass line and said heat exchanger are non-symmetric. 
     
     
         13 . The system as set forth in  claim 1 , wherein said valve is designed to achieve a change in pressure drop as said valve moves to, in turn, keep a total pressure drop across said system between said valve and said heat exchanger that is relatively close to constant as said valve changes the portion of the second fluid passing through said heat exchanger. 
     
     
         14 . A manned spaceship including a system for supplying air into an interior of said spacecraft comprising:
 a fluid supply for said air, said fluid supply for said air passing through a heat exchanger, and a temperature sensor for said air to sense a temperature of said air downstream of said heat exchanger;   a supply for a second fluid to change a temperature of said air, said supply for said second fluid passing through said heat exchanger;   a valve positioned upstream of said heat exchanger on said supply for said second fluid, and controlling a flow rate of said second fluid diverted into a bypass line compared to a flow rate of said second fluid directed through said heat exchanger, with said valve controlled by a control in response to feedback from said temperature sensor; and   said three-way valve changes the respective volumes delivered into said bypass line and through said heat exchanger in a non-linear manner with a change in valve position.   
     
     
         15 . The manned spaceship as set forth in  claim 14 , wherein said fluid passages in said valve are non-symmetric. 
     
     
         16 . The manned spaceship as set forth in  claim 14 , wherein said valve includes a rotating spool. 
     
     
         17 . The manned spaceship as set forth in  claim 16 , wherein fluid passages on said spool leading to said bypass line and said heat exchanger are non-symmetric. 
     
     
         18 . The manned spaceship as set forth in  claim 14 , wherein said valve moves axially, and two valve pistons control the respective flow to said bypass line and to said heat exchanger. 
     
     
         19 . The manned spaceship as set forth in  claim 14 , wherein fluid passages in said valve leading to said bypass line and said heat exchanger are non-symmetric. 
     
     
         20 . The manned spaceship as set forth in  claim 14 , wherein said valve is designed to achieve a change in pressure drop as said valve moves to, in turn, keep a total pressure drop across said system between said valve and said heat exchanger that is relatively close to constant as said valve changes the portion of the second fluid passing through said heat exchanger.