Element for emission of thermal radiation

Abstract

The present disclosure provides an element for emission of thermal radiation. The element comprises particles arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation. The thermal radiation predominantly has a wavelength or wavelength range within an atmospheric window wavelength range in which the atmosphere of the Earth has a reduced average absorption and emission compared with an average absorption and emission in an adjacent wavelength range whereby absorption by the element of radiation from the atmosphere is reduced.

1 . An element for emission of thermal radiation, the element comprising a component arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation, the thermal radiation predominantly having a wavelength or wavelength range within an atmospheric window wavelength range in which the atmosphere of the Earth has a reduced average absorption and emission compared with an average absorption and emission in an adjacent wavelength range whereby absorption by the element of radiation from the atmosphere is reduced. 
   
   
       2 . The element of  claim 1  wherein the atmospheric window wavelength range includes a minimum of the average absorption of the atmosphere of the Earth. 
   
   
       3 . The element of  claim 1  wherein the atmospheric window wavelength range is a wavelength range from 3 to 5 μm and/or from 7.9 μm to 13 μm. 
   
   
       4 . The element of  claim 1  wherein the element comprises particles arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation. 
   
   
       5 . The element of  claim 1  wherein the element comprises a layer arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation. 
   
   
       6 . The element of  claim 4  wherein the particles are distributed throughout the element and the element also comprises a material that is substantially transmissive for radiation having a wavelength within the atmospheric window range. 
   
   
       7 . The element of  claim 1  comprising a cover that is substantially transmissive for the thermal radiation and that is arranged for reduction of exchange of thermal energy by convection. 
   
   
       8 . The element of any  claim 7  comprising wall portions that define an interior space within which a medium that is to be cooled is in use located. 
   
   
       9 . The element of  claim 8  wherein the wall portions comprise a reflective material. 
   
   
       10 . The element of  claim 8  wherein at least some of the wall portions are thermally insulating. 
   
   
       11 . The element of  claim 1  comprising a structure that has projecting wall portions which are positioned so that, in use, incoming radiation from regions of the atmosphere, which are near the horizon, is substantially blocked off. 
   
   
       12 . The element of  claim 1  comprising a structure that has projecting wall portions that are reflective for the thermal radiation emitted by the component arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation. 
   
   
       13 . The element of  claim 12  wherein the projecting wall portions are positioned so that in use the emitted thermal radiation is directed in a direction towards Space and in a direction away from the horizon. 
   
   
       14 . The element of  claim 1  any one of comprising a concentrator for concentrating radiation. 
   
   
       15 . The element of  claim 1  wherein the element is substantially transparent for visible light. 
   
   
       16 . The element of  claim 1  wherein the element comprises a substantially transparent polymeric material that comprises the component for emission of the thermal radiation and wherein the element is arranged so that in use at least a portion of the incoming near infrared radiation is absorbed and the resulting absorbed thermal energy is at least partially re-emitted in the form of thermal radiation by the component arranged for emission of radiation having a wavelength within the atmospheric window wavelength range. 
   
   
       17 . The element of  claim 1  wherein the element forms a part of an object. 
   
   
       18 . A cooling system comprising thermally insulating wall portions and comprising the element of  claims 1  wherein the cooling system is arranged for cooling an object that is positionable in, and removable from, an interior formed by the thermally insulating wall portion. 
   
   
       19 . A cooling device for cooling a medium, the cooling device comprising an element for emission of thermal radiation, the element comprising particles arranged for receiving thermal energy and emitting at least a portion of the received thermal energy in the form of the thermal radiation, the thermal radiation predominantly having a wavelength or wavelength range within an atmospheric window wavelength range in which the atmosphere of the Earth has a reduced average absorption and emission compared with an average absorption and emission in an adjacent wavelength range whereby absorption by the element of radiation from the atmosphere is reduced. 
   
   
       20 . The cooling device of  claim 19  wherein the cooling device is arranged so that the medium is in indirect thermal contact with the element.