Solar thermal receiver with concentric tube modules

Abstract

A solar thermal receiver with concentric tube modules is disclosed. The outer two tubes ( 101, 102 ) of each module form an annular gap ( 104 ) for the inlet flow ( 109 ) of a heat transfer fluid (HTF). A third inner tube ( 103 ) allows for the outlet flow ( 108 ) of the HTF. Each of the concentric tube modules is bottom-supported so as to allow for thermal expansion. Embodiments may include a structural element ( 750 ) to mitigate oscillation of the concentric tube modules and/or a top-mounted bell-shaped cap ( 534 ).

1 - 2 . (canceled) 
     
     
         3 : A solar-thermal receiver comprising:
 a first tube;   a second tube wherein the diameter of the first tube is greater than the diameter of the second tube; and   a third tube wherein the diameter of the second tube is greater than the diameter of the third tube;   wherein the first tube, the second tube, and the third tube are mutually concentric, the second tube is disposed within the first tube providing an annular gap between the outer surface of the second tube and the inner surface of the first tube for an input flow of a heat transfer fluid (HTF), the third tube is disposed within the second tube, wherein the third tube is separated from the second tube by an internal volume, and wherein the inside of the third tube is a conduit providing for an output flow of the HTF.   
     
     
         4 : The solar thermal receiver of  claim 3  wherein the first tube, the second tube, and the third tube are connected to a header at only one end. 
     
     
         5 : The solar thermal receiver of  claim 3  wherein the internal volume between the second tube and the third tube further comprises at least one of: thermocouples, heating elements, heat absorbing materials, and insulation. 
     
     
         6 : The solar thermal receiver of  claim 3  wherein the annular gap between the outer surface of the second tube and the inner surface of the first tube further comprises a helical structure having an angle of ascent and configured to conduct an input flow of the HTF. 
     
     
         7 : The solar thermal receiver of  claim 6  wherein the helical structure further comprises a pitch that varies along the length of the tube. 
     
     
         8 : The solar thermal receiver of  claim 6  wherein the helical structure further comprises a pitch that remains constant along the length of the tube. 
     
     
         9 : The solar thermal receiver of  claim 3  wherein the first tube comprises an array of convex indentations disposed interstitial with an array of concave indentations on the second tube. 
     
     
         10 : The solar thermal receiver of  claim 3  further comprising an at least one baffle in the annular gap between the outer surface of the second tube and the inner surface of the first tube. 
     
     
         11 : The solar thermal receiver of  claim 3  further comprising an at least one angular flange comprising an at least one hole in the at least one angular flange in the gap between the outer surface of the second tube and the inner surface of the first tube. 
     
     
         12 : The solar thermal receiver of  claim 3  further comprising a throttle poppet valve, wherein the throttle poppet valve is further configured to adjust the flow rate of the HTF. 
     
     
         13 : A method of monitoring the flow and thermal state of a heat transfer fluid (HTF) in a solar thermal receiver comprising:
 providing a temperature measurement device proximate to an input flow of HTF;   providing a heater proximate to the input flow of HTF;   measuring a temperature of the input flow of HTF by the temperature measurement device proximate to the input flow of HTF;   determining, by a processor having addressable memory, whether the measured temperature of the input flow of HTF is below a set point;   if the temperature of the input flow of HTF is below the set point, then generating a command for the heater proximate to the input flow of HTF to turn on; and   otherwise, if the temperature of the input flow of HTF is not below the set point, then generating a command for the heater proximate to the input flow of HTF to turn off.   
     
     
         14 : The method of  claim 13 , wherein the provided temperature measurement device proximate to an input flow of HTF is a thermocouple. 
     
     
         15 - 17 . (canceled)