Auxilliary reservoir for a liquid system

Abstract

A liquid system for circulating a liquid through a circulation loop includes a liquid pump, a primary liquid reservoir and an auxiliary liquid reservoir. The liquid pump pressurizes liquid within the circulation loop. The primary liquid reservoir has a primary variable volume expandable to accommodate volumetric expansion of pressurized liquid up to a threshold volume. The auxiliary liquid reservoir has an auxiliary variable volume expandable only after the threshold volume is exceeded up to a maximum volume.

1 . A liquid system for circulating a liquid through a circulation loop, the liquid system comprising:
 a liquid pump for pressurizing liquid within the circulation loop;   a primary liquid reservoir in fluid communication with the circulation loop and having a primary variable volume expandable to accommodate volumetric expansion of pressurized liquid up to a threshold volume; and   an auxiliary liquid reservoir in fluid communication with the circulation loop and having an auxiliary variable volume expandable only after the threshold volume is exceeded up to a maximum volume.   
     
     
         2 . The liquid system of  claim 1  wherein the primary variable volume accommodates volumetric expansion of the liquid across operating pressures of the liquid pump up to a threshold pressure. 
     
     
         3 . The liquid system of  claim 2  wherein the auxiliary variable volume accommodates volumetric expansion of the liquid above the threshold pressure up to a maximum pressure. 
     
     
         4 . The liquid system of  claim 3  and further comprising:
 a relief valve connected to the circulation loop and configured to open above the maximum pressure. 
 
     
     
         5 . The liquid system of  claim 3  wherein the auxiliary liquid reservoir comprises a spring-charged bellows having a spring with a spring force that yields above the threshold pressure. 
     
     
         6 . The liquid system of  claim 5  wherein the primary liquid reservoir comprises a bootstrap reservoir. 
     
     
         7 . The liquid system of  claim 6  wherein the liquid pump and the primary liquid reservoir are packaged in a common housing and the auxiliary liquid reservoir is packaged in a separate housing. 
     
     
         8 . The liquid system of  claim 6  wherein the primary liquid reservoir includes a level sensor for determining a volume of fluid within the primary liquid reservoir. 
     
     
         9 . The liquid system of  claim 1  and further comprising:
 a liquid circulating through the circulation loop; and 
 a liquid load connected to the liquid pump through the circulation loop; 
 wherein the liquid load imparts a thermal input to the liquid. 
 
     
     
         10 . A liquid system comprising:
 a circulation loop;   a fluid pump configured to pressurize fluid within the circulation loop;   a primary reservoir in fluid communication with the circulation loop and configured to expand in volume under pressure within the circulation loop up to a threshold pressure; and   an auxiliary reservoir in fluid communication with the circulation loop and configured to expand in volume once the threshold pressure is exceeded.   
     
     
         11 . The liquid system of  claim 10  and further comprising:
 a liquid circulating through the circulation loop; and 
 a liquid load connected to the liquid pump through the circulation loop; 
 wherein the liquid load imparts a thermal input to the liquid. 
 
     
     
         12 . The liquid system of  claim 11  wherein the auxiliary reservoir comprises a spring charged bellows having a spring with a spring force that yields above the threshold pressure. 
     
     
         13 . The liquid system of  claim 12  wherein the primary reservoir comprises a bootstrap reservoir integrated into a housing of the fluid pump, and the auxiliary reservoir is packaged in a separate housing. 
     
     
         14 . The liquid system of  claim 12  wherein the primary reservoir includes a level sensor for determining a volume of fluid within the primary reservoir. 
     
     
         15 . The liquid system of  claim 10  wherein the auxiliary reservoir expands to a maximum volume after the primary reservoir expands to a threshold volume. 
     
     
         16 . A method of accommodating expanding fluid in a closed fluid circulation loop, the method comprising:
 circulating pressurized fluid in a closed fluid circulation loop using a pump;   expanding a volume of a primary reservoir connected to the closed fluid circulation loop up to a threshold volume to accommodate expansion of the pressurized fluid to a threshold level; and   expanding a volume of an auxiliary reservoir connected to the closed fluid circulation loop up to a maximum volume to accommodate expansion of the pressurized fluid from the threshold level to a maximum level.   
     
     
         17 . The method of  claim 16  wherein the volume of the primary reservoir and the volume of the auxiliary reservoir are expanded sequentially. 
     
     
         18 . The method of  claim 16  wherein the volume of the primary reservoir is expanded to a threshold pressure and the volume of the auxiliary reservoir is expended after the threshold pressure is reached. 
     
     
         19 . The method of  claim 18  wherein the step of expanding the volume of the primary reservoir comprises expanding a bootstrap reservoir integrated with the pump. 
     
     
         20 . The method of  claim 19  wherein the step of expanding the volume of the auxiliary reservoir comprises expanding a bellow-type reservoir having a spring that yields at the threshold pressure.