A refrigerator is any kind of enclosure (like a box, cabinet, or room) whose interior temperature is kept substantially lower than the surrounding environment.
The term "refrigerator" was coined by a Maryland engineer, Thomas Moore, in 1800. Moore's device would now be called an "ice box" — a cedar tub, insulated with rabbit fur, filled with ice, surrounding a sheet metal container. Moore designed it as as a means for transporting butter from rural Maryland to Washington, DC. Its operating principle was the latent heat of fusion associated with melting ice.
The term "air conditioning" was coined by Stuart Cramer in 1905 to describe his system for regulating the temperature and humidity inside a textile factory in the South (the humidity regulation was seen as more important than the temperature regulation). Willis Carrier also designed climate control systems for industry.
One of the first uses of air conditioning for personal comfort was in 1902 when the New York Stock Exchange's new building was equipped with a central cooling as well as heating system. Alfred Wolff, an engineer from Hoboken, New Jersey who is considered the forerunner in the quest to cool a working environment, helped design the new system, transferring this budding technology from textile mills to commercial buildings.
In 1906, Stuart Cramer first used the term "air conditioning" as he explored ways to add moisture to the air in his southern textile mill. He combined moisture with ventilation to actually "condition" and change the air in the factories, controlling the humidity so necessary in textile plants.
An early pioneer who did much to promote "controlled air" was Willis Carrier, a mechanical engineer who worked at the Buffalo Forge Company in Buffalo, New York. Subsequent subsidiary companies carrying his name helped conquer the temperature-humidity relationship, marrying theory with practicality. Starting in 1902, he designed a spray-type temperature and humidity controlled system. His induction system for multi-room office buildings, hotels, apartments and hospitals was just another of his air-related inventions. Many industry professionals and historians consider him the "father of air conditioning."
There are several basic refrigeration techniques:
Physician Dr. John Gorrie, Apalachicola, Florida, 1849. Rapidly expanding gases are cooled. Intended to cool hospital wards. Hot air was considered "bad", was thought to be the origin of tropical diseases, thus the name "malaria". Died before commercial models could be made. Design improved by William Siemens of Germany. Dr. Gorrie may have also invented the ice cube tray in its current form.
By widening the vessel … from the bottom upward the removal of the block of ice is … rendered more easy ….
To further facilitate the removal of the ice from the vessels [they are] made a little smaller at the bottom than at the top ….
In 1834 an American inventor named Jacob Perkins obtained the first patent for a vapor-compression refrigeration system, it used ether in a vapor compression cycle.
Follow along with this discussion using vapor-compression.pdf.
Note: liquids are not ideal gases, liquids are nearly incompressible.
Oliver Evans, USA, 1805, proposed but not built, evaporated sulfuric acid absorbed by water.
The first absorption machine was developed by Edmond Carré in 1850, using water and sulphuric acid. His brother, Ferdinand Carré developed the first ammonia/water refrigeration machine in 1859. Ferdinand Carré, France, ammonia absorption refrigerator, 1859. Established commercial success in the Confederate States during the US Civil War, since Union ice was not being transported to the South.
vapor absorption refrigerators can be powered by any heat Source: natural gas, propane, kerosene, butane?
schematic diagram — vapor-absorption-fridge.pdf
not efficiency, but coefficient of performance
These notes are a disaster.
The first true refrigerator (as opposed to an icebox) was built by Jacob Perkins in 1834. It used ether in a vapor compression cycle. The first vapor absorption refrigerator was developed by Edmond Carré in 1850, using water and sulfuric acid. His brother, Ferdinand Carré, demonstrated an ammonia/water refrigeration machine in 1859. Since 1834 more than 50 chemical substances have been used as refrigerants including …
|1830s||caoutchoucine (distillate of india rubber)|
|1840s||methyl ether (R-E170)||CH3-O-CH3|
|1850||sulfuric acid||H2SO4 / H2O|
|1859||ammonium hydroxide||NH3 / H2O|
|1866||chymogene (petrol ether and naphtha)|
|1870||methyl formate (R-611)||HCOOCH3|
|1875||sulfur dioxide (R-764)||SO2|
|1878||methyl chloride (R-40)||CH3Cl|
|1870s||ethyl chloride (R-160)||CH3-CH2Cl|
|1891||sulfuric acid blended with hydrocarbons|
|1900s||ethyl bromide (R-160B1)||CH3-CH2Br|
|1912||water vapor (R-718)||H2O|
|1926||methylene chloride (R-30)||CH2Cl2|
|Source:||Radermacher and Hwang, University of Maryland|
The first mechanical refrigerators had to be connected to the sewer system to dispose of the refrigerant on a regular basis. In the 1930s and 1940s the halocarbon refrigerants (commonly known by such trade names as "Freon," "Genetron," "Isotron," etc.) were developed, giving the industry a strong push into the household market because of their suitability for use with small horsepower motors.
The most important members of the group have been
Stable? Yes. Too stable! Stays around and accumulates in the atmosphere. Shifts the equilibrium between O2 and O3 in the stratosphere. global warming. Production of chlorofluorocarbons (CFCs) ended in 1995 in developed countries.
Production of R-12 was halted by the Clean Air Act on January 1, 1996. Today the remaining supplies are product which has been recovered and reclaimed back to a Chemically Pure State in accordance to ARI - 700 Standard. The ARI Standard is basically a virgin specification. Persons arguing that the supply of virgin product is still available is probably unrealistic, since most of the reserves were depleted in the 1st year. DoD Public Law prohibits the purchase of R-12 except for existing systems, when retrofit has been determined by technical staff to be prohibitive. Senior or Executive approval of this product to be purchased is required.
|trade name||corporation||trade name||corporation|
|Arcton||Imperial Chemicals||Halon||ASP International|
|Forane||Elf Atochem||Jeffcool||Jefferson Chemical|
|Genetron||Allied Signal||Ucon||Union Carbide|
|occupational exposure limit||1000||p.p.m.|
|saturated vapor pressure||652||kPa|
|specific heat capacity, liquid||971||J/kg K|
|specific heat capacity, vapor||617||J/kg K|
|latent heat of vaporization||139.3||kJ/kg|
|thermal conductivity, liquid||0.0743||W/m K|
|thermal conductivity, vapor||0.00958||W/m K|
|viscosity (+15 ℃)||0.20||mPa s|
|property||ammonia||carbon dioxide||sulfur dioxide||freon 12|
|normal boiling point (℃)||−34||−78||−10||−30|
|latent heat (kJ/mol)||24||25||25||22|
|pressure at 0 ℃ (atm)||4||35||2||3|
|pressure at 50 ℃ (atm)||20||> 60||9||12|
|Source:||William Gumprecht, Kennesaw State University|