User:Engineeringfridge/sandbox: Difference between revisions
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The RV Fridge Wiki page will use [[drawing]]s to share the [[physics]] governing the process used for common RV [[refrigerator]]s, discuss [[safety]], and tie together the science for this widely misunderstood refrigeration process. |
The RV Fridge Wiki page will use [[drawing]]s to share the [[physics]] governing the process used for common RV [[refrigerator]]s, discuss [[safety]], and tie together the science for this widely misunderstood refrigeration process. |
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The first absorption refrigeration system was patented by [http://www.britannica.com/EBchecked/topic/1981793/adsorption-chiller#ref1201934 Ferdinand Carre] in 1859. This refrigeration system had mechanical pumps and throttling valves which change the pressures in the refrigeration cycle<ref>http://www.mhprofessional.com/product.php?isbn=0073398179</ref>. This page will focus on the single pressure absorption refrigerator due to the fact that it is easy to sustain these fridges in an RV as long as [[propane]] (LP gas) is available. The RV Fridge is considered a single pressure absorption refrigeration (SPAR) system. The SPAR was patented by Baltzar von Platen and Carl Munters in 1923<ref>http://www.google.com/patents/US1669269</ref>. |
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Following is a [[block diagram]] and a simplified drawing of a typical absorption type RV Fridge. The block diagram is a simplification of the fridge cycle which shows the key [[components]] combined with the [[fluid flow]] within the [[circuit]]. The simplified drawing more closely resembles the actual refrigeration cycle so that the reader can draw a connection between the components on their fridge and what is occurring within the tubing. |
Following is a [[block diagram]] and a simplified drawing of a typical absorption type RV Fridge. The block diagram is a simplification of the fridge cycle which shows the key [[components]] combined with the [[fluid flow]] within the [[circuit]]. The simplified drawing more closely resembles the actual refrigeration cycle so that the reader can draw a connection between the components on their fridge and what is occurring within the tubing. |
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Revision as of 18:44, 1 January 2015
 | This article needs additional citations for verification. (December 2014) |
 | This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. (December 2014) |
The RV Fridge Wiki page will use drawings to share the physics governing the process used for common RV refrigerators, discuss safety, and tie together the science for this widely misunderstood refrigeration process.
The first absorption refrigeration system was patented by Ferdinand Carre in 1859. This refrigeration system had mechanical pumps and throttling valves which change the pressures in the refrigeration cycle[1]. This page will focus on the single pressure absorption refrigerator due to the fact that it is easy to sustain these fridges in an RV as long as propane (LP gas) is available. The RV Fridge is considered a single pressure absorption refrigeration (SPAR) system. The SPAR was patented by Baltzar von Platen and Carl Munters in 1923[2].
Following is a block diagram and a simplified drawing of a typical absorption type RV Fridge. The block diagram is a simplification of the fridge cycle which shows the key components combined with the fluid flow within the circuit. The simplified drawing more closely resembles the actual refrigeration cycle so that the reader can draw a connection between the components on their fridge and what is occurring within the tubing.
The block diagram shows the flow of fluids (Qx) along with the flow direction arrows. Also, the heat input (endothermic process) and heat rejection (exothermic process) for the respective components has been identified. The fluid flow is as follows:
Q1: The yellow line is the holding tank mixture of liquid water, ammonia, and a rust inhibitor.
Q2: The blue line is the weak solution. The weak solution preferably consists of only water and the rust inhibitor as a result of the distillation process.
Q3: The pink line is pure ammonia gas (anhydrous ammonia). The heat input in the fired boiler causes the liquid ammonia within Q1 to boil (go through a phase change).
Q4: The green line is ammonia liquid. The condenser cools the ammonia gas (Q3) to produce the working fluid which removes the heat from the refrigerated compartment.
Q5: The pink line is once again ammonia gas. The ammonia gas is produced by evaporation of the ammonia liquid (Q4) within the evaporator. The evaporation of the liquid ammonia is due to Dalton's law of partial pressures. The pressure vessel which is commonly referenced as a cooling unit in the RV industry has all of the air evacuated and a hydrogen charge of approximately 350psi (~2.4MPa).
Q2 + Q5 → Q1: In the absorber coil the circuit is completed. Q1 is reconstituted due to the fact that ammonia has an affinity for water.[3] The weak solution (Q2) absorbs the ammonia gas thereby returning the ammonia to a liquid state to reenter the boiler and start the process over.
Place rv-fridge-simplified-schematic here when upload available
The RV fridge simplified schematic more closely resembles the actual cooling unit. The same color schemes have been use for the fluid flow as the block diagram. This section will have more detail including function, safety, and troubleshooting for each component.
Under construction, please check back as we build, thanks for your use of Wikipedia!
Further reading please see [4]
References