Device for harnessing solar energy with vapor insulating heat transfer core

Abstract

A solar collector is provided, in one embodiment. The solar collector comprises a heat core to convert incident radiation into heat; a wicking layer spaced from the heat core to absorb infrared radiation emitted by the heat core due to the conversion of incident radiation into heat; an inlet to introduce a heat transfer fluid into the wicking layer; wherein the absorption of the infrared radiation is by the heat transfer fluid in the wicking layer and causes a portion of the heat transfer fluid to enter into a vapor phase thereof which propagates into the heat core where it undergoes heating; and an outlet to transport the heated vapor phase of the heat transfer fluid out of the collector.

1 . A method for heating a heat transfer fluid, comprising:
 exposing a heat core to incident radiation to cause heating of said heat core, whereupon the heat core emits infrared radiation;   introducing a heat transfer fluid into a wicking layer spaced from the heat core to absorb the infrared radiation emitted by the heat core, whereupon at least some of the heat transfer fluid is converted into a vapor that enters the heat core;   heating the vapor in the heat core; and   extracting the heated vapor to perform work.   
     
     
         2 . The method of  claim 1 , wherein heating the vapor comprises superheating the vapor. 
     
     
         3 . The method of  claim 1 , further comprising controlling a rate at which the heat transfer fluid is introduced into the wicking layer to ensure wetness of all portions of the wicking layer. 
     
     
         4 . A solar collector, comprising:
 a heat core to convert incident radiation into heat;   a wicking layer spaced from the heat core to absorb infrared radiation emitted by the heat core due to the conversion of incident radiation into heat;   an inlet to introduce a heat transfer fluid into the wicking layer;   wherein the absorption of the infrared radiation is by the heat transfer fluid in the wicking layer and causes a portion of the heat transfer fluid to enter into a vapor phase thereof which propagates into the heat core where it undergoes heating; and   an outlet to transport the heated vapor phase of the heat transfer fluid out of the collector.   
     
     
         5 . The solar collector of  claim 4 , wherein heat transfer fluid lost from the wicking layer through conversion into the vapor phase is replaced through a capillary action that pumps more heat transfer fluid into the wicking layer through the inlet. 
     
     
         6 . The solar collector of  claim 5 , which is tuned in terms of ability of the heat core to convert incident radiation into heat, wicking capacity of the wicking layer, properties of the heat transfer fluid, separation distance between the heat core and the wicking layer, and cross-section of the inlet to ensure that all portions of the wicking layer remain wet with heat transfer fluid during operation. 
     
     
         7 . The solar collector of  claim 4 , further comprising a housing for the heat core, and the wicking layer lines an internal surface of the housing. 
     
     
         8 . The solar collector of  claim 7 , wherein the housing is planar. 
     
     
         9 . The solar collector of  claim 7 , wherein the housing is cylindrical. 
     
     
         10 . The solar collector of  claim 7 , wherein a portion of the housing that is operatively exposed to incident radiation in the form of solar flux is transparent to the incident radiation thereby to define a window. 
     
     
         11 . The solar collector of  claim 10 , wherein said window is treated with an anti-reflective material. 
     
     
         12 . The solar collector of  claim 4 , wherein the wicking layer comprises a porous material. 
     
     
         13 . The solar collector of  claim 12 , wherein the porous material comprises film laced with a network of continuous interconnected passages to create a wicking action through capillary forces. 
     
     
         14 . The solar collector of  claim 4 , wherein the wicking layer comprises a surface structured material. 
     
     
         15 . The solar collector of  claim 14 , wherein the surface structured material comprises surface grooves to facilitate a capillary pumping action. 
     
     
         16 . The solar collector of  claim 5 , wherein the wicking material facing the housing is transparent to visible light and has an index of refraction that is matched to that of the heat transfer fluid. 
     
     
         11 . The solar collector of  claim 4 , wherein the heat core comprises a thermally conducting metal or a carbon foam matrix. 
     
     
         18 . The solar collector of claim  17 , wherein the heat core is treated to make it light absorbing. 
     
     
         19 . The solar collector of  claim 4 , wherein the heat core comprises a thermally conductive fill material having interstitial spaces to promote conductive heat transfer to the vapor phase of the heat transfer fluid. 
     
     
         20 . The solar collector of claim  17 , wherein the heat core comprises an axial passage extending through the fill material. 
     
     
         21 . The solar collector of  claim 18 , wherein the heat core comprises a pair of metal plates each comprising interstitial spaces to promote conductive heat transfer to the vapor phase of the heat transfer fluid, the fill material being located within the metal plates. 
     
     
         22 . The solar collector of  claim 4 , wherein the heat core comprises a non-porous hollow cylinder filled with a porous material having interstitial spaces to promote conductive heat transfer to the vapor phase of the heat transfer fluid. 
     
     
         23 . The solar collector of  claim 22 , wherein the hollow cylinder is metallic and is able to withstand pressures at least 20 bar. 
     
     
         24 . The solar collector of  claim 23 , wherein the heat core comprises an egress end that is hermetically sealed with the outlet. 
     
     
         25 . The solar collector of  claim 23 , wherein the heat core comprises an ingress end through which the vapor phase of the heat transfer fluid enters the heat core, said ingress end being plugged by a capillary pump. 
     
     
         26 . The solar collector of  claim 25 , wherein the capillary pump comprises a porous material designed to perform a pumping action on the heat transfer fluid due to variations in pore size. 
     
     
         27 . The solar collector of  claim 24 , wherein the porous material comprises at least two layers in contact with each other, each layer having pores of a different size. 
     
     
         28 . An energy system, comprising:
 an array of solar collectors;   a first heat transfer loop coupled to the array to provide a recirculation path for heated heat transfer fluid from and to the array; and   a second heat transfer loop comprising at least one heat exchanger to extract heat from the heated heat transfer fluid in the first heat transfer loop to perform work; wherein at least one solar collector, comprises:
 a heat core to convert incident radiation into heat; 
 a wicking layer spaced from the heat core to absorb infrared radiation emitted by the heat core due to the conversion of incident radiation into heat; 
 an inlet to introduce a heat transfer fluid ‘into the wicking layer; 
 wherein the absorption of the infrared radiation is by the heat transfer fluid in the wicking layer, and causes a portion of the heat transfer fluid to enter into a vapor phase thereof which propagates into the heat core where it undergoes heating; and 
 an outlet to transport the heated vapor phase of the heat transfer fluid out of the collector. 
   
     
     
         29 . The energy system of  claim 28 , wherein the first heat transfer loop comprises an energy accumulation device to store heat from the heated heat transfer fluid in the first heat transfer loop. 
     
     
         30 . The energy system of  claim 28 , wherein the energy accumulator selectively adds heat to the heated heat transfer fluid in the first heat transfer loop. 
     
     
         31 . An energy system, comprising:
 an array of solar collectors;   a heat transfer loop coupled to the array to provide a recirculation path for heated heat transfer fluid from and to the array; and   at least one heat exchanger positioned within the heat transfer loop to extract heat from the heated heat transfer fluid; wherein at least one solar collector in said array comprises:
 a heat core to convert incident radiation into heat; 
 a wicking layer spaced from the heat core to absorb infrared radiation emitted by the heat core due to the conversion of incident radiation into heat; 
 an inlet to introduce a heat transfer fluid into the wicking layer; 
 wherein the absorption of the infrared radiation is by the heat transfer fluid in the wicking layer, and causes a portion of the heat transfer fluid to enter into a vapor phase thereof which propagates into the heat core where it undergoes heating; and 
 an outlet to transport the heated vapor phase of the working fluid out of the collector. 
   
     
     
         32 . The energy system of  claim 31 , wherein the heat transfer loop comprises an energy accumulation device to store heat from the heated working fluid in the first heat transfer loop. 
     
     
         33 . The energy system of  claim 31 , wherein the energy accumulator selectively adds heat to the heated working fluid in the heat transfer loop.