Diffuser for thermal storage tank

Abstract

A diffuser is provided for use in a thermal storage tank. The diffuser includes a fluid inlet to receive a flow of liquid into the diffuser, and a fluid outlet to discharge the flow of liquid out of the diffuser into an internal volume of the thermal storage tank. A flow circuit extends between the fluid inlet and the fluid outlet. A plurality of flow sections are sequentially arranged along the flow circuit. Each one of the plurality of flow sections defines a cross-sectional flow area for the flow of liquid. The cross-sectional flow area within any one of the plurality of flow sections is greater than the cross-sectional flow area within any of the plurality of flow sections arranged upstream of said one of the plurality of flow sections.

What is claimed is: 
     
         1 . A method of discharging a thermal storage tank, comprising:
 directing a flow of liquid into a fluid inlet of a diffuser arranged within the thermal storage tank;   directing an entirety of the flow of liquid sequentially through a plurality of flow sections of the diffuser, each one of the plurality of flow sections defining a cross-sectional flow area of a circular or annular shape for the flow of liquid, wherein the cross-sectional flow area within any one of the plurality of flow sections is greater than the cross-sectional flow area within any of the plurality of flow sections arranged upstream of said one of the plurality of flow sections; and   directing the flow of liquid through a fluid outlet of the diffuser into a fluid volume of the thermal storage tank.   
     
     
         2 . The method of  claim 1 , wherein the flow sections are arranged along a common central axis of symmetry. 
     
     
         3 . The method of  claim 2 , wherein the flow of liquid is directed into the fluid inlet in a flow direction that is parallel to the common central axis of symmetry, and wherein the flow of liquid is directed through the fluid outlet in a direction that is perpendicular to the common central axis of symmetry. 
     
     
         4 . The method of  claim 2 , wherein the common central axis of symmetry is aligned with a central axis of symmetry of the thermal storage tank. 
     
     
         5 . The method of  claim 1 , wherein directing the flow of liquid sequentially through the plurality of flow sections of the diffuser comprises directing the flow of liquid by a plurality of cylindrical baffles, each one of the plurality of cylindrical baffles fluidly separating two sequentially arranged ones of the plurality of flow sections. 
     
     
         6 . The method of  claim 5 , wherein the plurality of cylindrical baffles includes at least four cylindrical baffles. 
     
     
         7 . The method of  claim 5 , wherein directing the flow of liquid sequentially through the plurality of flow sections of the diffuser comprises directing the flow of liquid by a pair of spaced apart planar walls, one or more of the plurality of cylindrical baffles extending from a first one of said planar walls and spaced away from a second one of said planar walls, and one or more of the plurality of cylindrical baffles extending from the second one of said planar walls and spaced away from the first one of said planar walls. 
     
     
         8 . The method of  claim 7 , wherein the fluid outlet of the diffuser is provided in a cylindrical outer wall extending between the pair of spaced apart planar walls, the diffuser having an outer boundary defined by the cylindrical outer wall and the pair of spaced apart planar walls. 
     
     
         9 . The method of  claim 8 , wherein the fluid outlet comprises a plurality of openings in the cylindrical outer wall, the plurality of openings having a non-uniform spacing along an axial direction of the cylindrical outer wall. 
     
     
         10 . The method of  claim 8 , wherein the cylindrical outer wall defines an outer diameter of the outer boundary and wherein the pair of spaced apart planar walls define a height of the outer boundary, the outer diameter being in the range of two to five times the height. 
     
     
         11 . A method of discharging a thermal storage tank, comprising:
 removing, at a top end of the thermal storage tank, a first flow of liquid from an internal volume of the thermal storage tank, wherein the first flow of liquid is at a first temperature when discharging is initiated;   receiving a second flow of liquid at a second temperature that is at least 100 degrees Fahrenheit lower than the first temperature into a diffuser arranged at a bottom end of the thermal storage tank at a first kinetic energy state;   directing an entirety of the second flow of liquid sequentially through a plurality of flow sections within the diffuser, each one of the plurality of flow sections defining a cross-sectional flow area for the entirety of the second flow of liquid, the cross-sectional flow area of any one of the plurality of flow sections being greater than the cross-sectional flow area of any of the plurality of flow sections arranged upstream of said one of the plurality of flow sections; and   discharging the second flow of liquid from the diffuser into an internal volume of the thermal storage tank at a second kinetic energy state lower than the first kinetic energy state, wherein the first flow of liquid is at a third temperature after a volume of liquid equal to 90% of the internal volume has been discharged by removing the first flow of liquid and wherein the third temperature in degrees Fahrenheit is at least 95% of the first temperature in degrees Fahrenheit.   
     
     
         12 . The method of  claim 11 , wherein the step of directing the entirety of the second flow of liquid sequentially through a plurality of flow sections within the diffuser comprises directing the second flow of liquid through a plurality of concentrically arranged annular flow areas. 
     
     
         13 . The method of  claim 11 , wherein the first kinetic energy state is at least twenty-five times greater than the second kinetic energy state. 
     
     
         14 . The method of  claim 11  wherein the diffuser is a first diffuser and wherein removing the first flow of liquid includes directing the first flow of liquid through a second diffuser arranged at the top end of the thermal storage tank.