Solar collectors structure

The sources for outgassing include preformed seals, seal caulks, room temperature vulcanizing polymers, thermal insulations, polymeric coatings, and polymeric materials used in solar collector structural applications. 

The cost-effective deployment of large areas of solar collectors will most probably be polycrystalline materials, with all index planes emerging at the surface. Therefore, it is not expected that the structural determination of solar materials surfaces will be applied except for a few special cases. However, determining S/S inter facial structures is important, as shown by Figs. 6-9 in Ref. 2. The challenge in solar interface research will be to understand the changes in surface activity of heterogeneous real surfaces and interfaces. Here, SEM and possibly STEM techniques should be used extensively. 

Properties of Reticulated Ceramics. Reticulated ceramics are used as flame holders for the combustion of gaseous and liquid fuels and in high-temperature solar collectors. Because of their open structure and high porosity (above 80 percent), these materials have a small effective extinction coefficient relative to most porous materials. 

The Insulation In the BNL solar collector design uses rigid Insulation as a structural member. This member Is presently made from glass reinforced polylsocyanurate with a aluminum foil facer (Thermax, Celotex). The sheet metal frame Is parametrically coupled to the rigid Insulation and Is under compression when the... 

Many solar dryers described in the literature are simple greenhouse kilns (e.g., Langrish and Keey, 1992). In these units, the solar collector is fitted within the structure that holds the load and the airflow is maintained by fans. The solar energy, in other cases, is collected externally in heat-storage systems or panels, as illustrated in Figure 40.49. Greenhouse kilns have attractions in simplicity of construction and operation. 

In the following sections/ we shall discuss adhesion chemistry/ adhesion physics / radiation-curable adhesiveS/ high-temperature adhesiveS/ anaerobic and structural adhesiveS/ hot-melt adhesives/ film adhesiyes/ waterborne adhesives/ aerospace structural adhesiveS/ conventional sealants/ advanced aerospace sealants/ and adhesives and sealants for solar collectors. 

Besides durability, premium sealants are judged by special properties as shown in Table 4. The ability to take on greater elongation and compression is measured by movement capability in terms of joint width. The stability to UV exposure is important for those glazing and insulation compounds used in modern high-rise structures. Thermal stability is in demand for solar collectors, or for other structural materials. On the basis of these evaluations, we can foresee future trends of sealants as shown in Table 4. Silicones appear to out-perform others. In the meantime, technical advances will provide low-modulus polysulfides, and better movement ability for both polysulfides and polyurethanes. Their cure time will be decreased and the UV stability will be improved to match or compete with silicones. All three will be developed for better adhesion under the un-primed conditions. 

Adhesives and sealants used for the aerospace structures must endure severe environments. Another family of adhesive materials has also been developed for solar collectors, presumably based on the same ability to endure severe environments. Though there are different kinds of severe environments, conventional polymers generally do not survive in the solar collector environment. We shall discuss those adhesive materials used for solar applications in the following section. 

Adhesives (128) play an important role in the construction of a solar parabolic trough reflector. The adhesives should be compatible with silvered glass mirrors and should be able to carry structural loads. Moreover the adhesives should be durable for at least twenty years without losing their properties. Adhesives screened for solar collectors were epoxies, urethanes, and acrylics. Three types of stress conditions were identified as the most likely causes of failure in the trough modules ... 

It is advisable to refer to the first paragraph of the Appendix (Section 10.12) before reading the following sections. The following discussion refers only to Satellite 1 (Little, 2011) positioned at GEO as discussed in the Appendix. The support structures for the solar collectors and... 

The two types of support structures for the solar collectors and equipment that will be considered are the rigid deployable skeletal (RDS) structure and the rigidised inflatable flexible continuum (RIFC) structure both types of structure need to be lightweight and rigid and, in the case of the skeletal structure, high modulus composite materials would be used. In addition, the structures must be able to be folded to a minimum volume to be placed in the cargo bay of the Launch Vehicle, launched and deployed at LEO, and then taken to GEO by space tug,Wingo (2004). 

Rigid deployable skeleton support structure (RDSS) for solar collectors and equipment... 

Rigidised inflatable flexible continuum (RIFC) support structure for solar collectors and... 

Considering an outline design as suggested by Little (2011), the collected electrical energy from solar collectors in Satellite 1 at GEO would be beamed to Earth by lasers onto Satellite 2 positioned some 20 km above the Earth. Satellite 2 would support the equipment to transform the laser to microwaves, which would be beamed to a ground receiver. Ideally, the structural system to support the collectors and equipment for Satellites 1 and 2 would be fabricated from a polymer/fibre composite skeletal structure however, it is the structural support system for Satellite 1 at GEO which this chapter has discussed. The two satellites in relationship to the sun and Earth are shown in Rg. 10.11. 

The rigid deployable skeletal structure to support the solar collectors... 

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