Expansion joints for panels in solar boilers

Abstract

A boiler for a solar receiver includes a first receiver panel having a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel. A second receiver panel has a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel. The boiler tubes of the second receiver panel are substantially parallel to the boiler tubes of the first receiver panel. The first and second receiver panels are separated by a gap. A panel expansion joint is connected to the first and second receiver panels across the gap, wherein the panel expansion joint is configured and adapted to allow for lengthwise thermal expansion and contraction of the receiver panels along the boiler tubes, and to allow for lateral thermal expansion and contraction of the receiver panels toward and away from one another, while blocking solar radiation through the gap.

What is claimed is: 
     
         1 . A boiler for a solar receiver comprising:
 a) a first receiver panel having a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel;   b) a second receiver panel having a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel, wherein the boiler tubes of the second receiver panel are substantially parallel to the boiler tubes of the first receiver panel, and wherein the first and second receiver panels are separated by a gap;   c) a panel expansion joint connected to the first and second receiver panels across the gap, wherein the panel expansion joint is configured and adapted to allow for lengthwise thermal expansion and contraction of the receiver panels along the boiler tubes, and to allow for lateral thermal expansion and contraction of the receiver panels toward and away from one another, while blocking solar radiation through the gap, wherein the panel expansion joint includes first and second T-bar assemblies each attached to a backside of a respective one of said receiver panels, the T-bar assemblies being slidably connected by a connecting plate fixedly attached to one of the T-bar assemblies, and a fastener inserted through an elongated slot in said connecting plate and fixedly secured to the other one of the T-bar assemblies.   
     
     
         2 . A boiler for a solar receiver comprising:
 a) a first receiver panel having a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel;   b) a second receiver panel having a plurality of substantially parallel boiler tubes fluidly connecting an inlet header of the panel to an outlet header of the panel, wherein the boiler tubes of the second receiver panel are substantially parallel to the boiler tubes of the first receiver panel, the first and second receiver panels being separated by a gap; and   c) first and second T-bar assemblies each attached to a backside of a respective one of said receiver panels, the T-bar assemblies being slidably connected by a connecting plate fixedly attached to one of the T-bar assemblies, and a fastener inserted through an elongated slot in said connecting plate and fixedly secured to the other one of the T-bar assemblies,   wherein an endmost tube of each of said panels is attached to an adjacent tube of the respective panel by a membrane at an angle such that adjacent endmost tubes are displaced from a plane defined by the tubes in each of the respective first and second receiver panels in opposite directions, such that solar radiation is prevented from passing through the gap and such that lateral thermal expansion and contraction of the receiver panels toward and away from one another is permitted by the slidable connector of the T-bar assemblies.   
     
     
         3 . A boiler as recited in  claim 2 , wherein the panels form a corner with respect to one another, and wherein each of the endmost tubes at the corner is rigidly connected by a membrane at about a 45° angle with respect to each of the receiver panels. 
     
     
         4 . A boiler as recited in  claim 2 , wherein each of the T-bar assemblies comprises:
 upper and lower tube clips welded to every other boiler tube of each said panel;   a first plate inserted into the upper and lower tube clips, the first plate running the width of each panel;   a support plate inserted behind the first plate into the upper and lower tube clips, resting on the lower tube clip and running the width of each panel and having a space between the support plate and the upper tube clips to allow for thermal expansion; and   a T-bar welded to the support plate for each panel such that it is arranged substantially perpendicularly to the support plate, wherein the connecting plate slidably connects adjoining T-bars at the panel gap.