solar energy
2006-10-02 20:00:59 · 3 answers · asked by Anonymous in Education & Reference ➔ Higher Education (University +)
Black chromium plating bath is used for selective chromium coating. Flat plate or focusing type solar collectors require this type of selective coatings for efficient solar heat absorption . Black chromium coating has good corrosion resistance. In addition, this type of coating can be used on machinery parts such as certain parts of printing machinery, parts of optical instruments etc. which need coating to minimize reflection.
Black chromium plating bath is used for selective chromium coating. Flat plate or focusing type solar collectors require this type of selective coatings for efficient solar heat absorption . Black chromium coating has good corrosion resistance. In addition, this type of coating can be used on machinery parts such as certain parts of printing machinery, parts of optical instruments etc. which need coating to minimize reflection. Other applications include using solar energy for drying cereals in godowns, as an anti reflection coating on optical mounts and for decorative coatings on watches, jewelry, furnitures, etc.
The special requirements of a black chromium plating bath for solar collectors are :
The bath should be operated at room temperature
The plating current density should be low
The coating should be uniform
The bath should have good shelf life
The bath should have good working life
The coating should have high absorptance in the visible region of solar radiation.
The coating should have low emittance in the infrared region
The bath should have high tolerance to impurities
The bath should have simple regeneration and replenishment procedure
The coating should have good corrosion resistance
The coating should have high thermal stability
The bath should have high stability above room temperature.
PROCESS
The process being offered in this proposal uses a bath which contains special additives and fulfills all the above requirements. Water temperature in solar plate collectors coated in this bath can rise above 800 C after about six hours of sunshine. The black chromium coating bath is stable upto 3500 C and can therefore be used for collectors operating upto 3000 C .
2006-10-06 04:03:04 · answer #1 · answered by Wicked 7 · 0⤊ 0⤋
The coating on Himin’s solar collector is graded-cermet layer selective surfaces and consists of bottom metal layer, HMVF cermet absorbing layer, LMVF cermet absorbing layer and AR-coating with composite film of SS-OX-ALNYOZ. However, the coatings’ constituent ratio for vacuum and air application are different.
Please share your detail information with us maybe we can discuss it.Welcome to any questions to my email zhangfenli@himin.com.
2015-12-27 18:14:34 · answer #2 · answered by Zhang 2 · 0⤊ 0⤋
now the coated film technology is interference film technology. its componet is anti-reflection layer, absorbtanace layer and infrared-reflection layer. anti-reflection layer is made up of aluminium nitride.absorbtanace layer is made up of aluminium and aluminium nitride. infrared-reflection layer is made up of copper.
2016-01-05 19:40:29 · answer #3 · answered by ? 2 · 0⤊ 0⤋