Chapter 1: The Problem and Its Setting Introduction Before the year 1830, due to the lack of ice-storehouses and iceboxes, few Americans used ice for the refrigeration of food. As these two methods of reser!ation become broadly a!ailable, eole used axes and saw to har!est ice for their storehouses wh ich is ro!ed to be di ff icult, dang erous and certainly did not resemble anything that could be dulicated on a commercial scale. Artific ial refrig eration bega n when "cottis h rofe ssor#illiam $ullen designed a small refrigerating machine in 1%&&. 'e used a umto create a artial !acuum o!er a container ofdiethyl ether, which has undergone a heating rocess, absorbing heat from the surrounding air. (t resulted in roducing a small amount of ice, but had no ractical alication at that time. (n 18)0, *nglish scientist +ichael araday li u ef ie d ammo ni a an d ot her gase s by us ing hi gh ressure and low temeratures, and in 183, an American exatriate to /reat Britain, acob erkins, built the first working !aour-comression refrigeration system. (t was a closed cycle that could oerate continuously, 2( am enabled to use !olatile fluids for the urose of roducing the cooling or freeing of fluids, and yet at the same time constantly condensing such !olatile fluids, and bringing them again into oeration without waste.4 'e said in his atent. 5here ha!e been a few studies in connection with this toic, comaring water to other refrige rants but this researc h does not only limit to water as the main sub6ect but also to the different refrigerants readily a!ailable in the software for simulation, common to what industries use, and are still considered not to do much harm to the en!ironment. 5he +ech anic al *ngineering degr ee offe rs a course sub6ect in ref rigera tion7 under it are the toics about the dif ferent ref rig erants and refrigeration cycle. 'ence, the urose of this research is to in!estigate the refrigerants used in the refrigeration systems for the aim of imro!ing theircoe ff ici ent of er for mance $9:. (n add iti on, learn ing the ri nci les ofther mody namic s, heat tr ansf er, temerat ur e to r essure relationshi , 1
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Before the year 1830, due to the lack of ice-storehouses and
iceboxes, few Americans used ice for the refrigeration of food. As these two
methods of reser!ation become broadly a!ailable, eo le used axes and
saw to har!est ice for their storehouses which is ro!ed to be difficult,
dangerous and certainly did not resemble anything that could be du licated
on a commercial scale. Artificial refrigeration began when "cottish rofessor
#illiam $ullen designed a small refrigerating machine in 1%&&.
'e used a um to create a artial !acuum o!er a container of diethyl ether, which has undergone a heating rocess, absorbing heat from
the surrounding air. (t resulted in roducing a small amount of ice, but had no
ractical a lication at that time. (n 18)0, *nglish scientist +ichael araday
li uefied ammonia and other gases by using high ressure and low
tem eratures, and in 183 , an American ex atriate to /reat Britain, acob
erkins, built the first working !a our-com ression refrigeration system. (t was
a closed cycle that could o erate continuously, 2( am enabled to use !olatilefluids for the ur ose of roducing the cooling or free ing of fluids, and yet at
the same time constantly condensing such !olatile fluids, and bringing them
again into o eration without waste.4 'e said in his atent.
5here ha!e been a few studies in connection with this to ic,
com aring water to other refrigerants but this research does not only limit to
water as the main sub6ect but also to the different refrigerants readily a!ailable
in the software for simulation, common to what industries use, and are stillconsidered not to do much harm to the en!ironment.
5he +echanical *ngineering degree offers a course sub6ect in
refrigeration7 under it are the to ics about the different refrigerants and
refrigeration cycle. 'ence, the ur ose of this research is to in!estigate the
refrigerants used in the refrigeration systems for the aim of im ro!ing their
coefficient of erformance $9 :. (n addition, learning the rinci les of
thermodynamics, heat transfer, tem erature to ressure relationshi ,
5he study is uantitati!e research. @ata from the study is
needed to come u with a !alue to determine the efficiency of the refrigeration
system. 5he !alues will come from the simulated flow !alues and manually
com uted !alues. 5he data will be achie!ed through the formula based from
the book of "toecker and ones about refrigeration systems.
'.# Collection o! &ata
*ach refrigerant will be tested and data must be gathered in
order to com are the results of the ex eriment. @ata can be obtained through
two methods res ecti!ely by using a simulation rogram, /enetronro erties1.), and using the formula for manual calculations. 5hrough the
simulation rogram, the $9 or $oefficient of erformance of the refrigeration
system is gi!en directly also the mass flow of the system, cooling ca acity
and heating ca acity of the refrigeration system. "econd method is using the
formula of the standard !a or com ression cycle and com uting the s ecific
!alues of each refrigerant in order to accurately determine and to differentiate
ro erly the coefficient of erformance of the refrigeration system. All datamust be ro erly organi ed according to ty e of refrigerant used. 5he largest
$9 is not the best but one of the best refrigerants that can be used in the
refrigerant cycle.
'.' Task &escription and Schedule
;efrigerants must be di!ided among grou members in order tobe time efficient and ac uire the data much faster. At least 1 refrigerant must
be sol!ed within )-3 days by each student in order to meet the deadline. 5he
simulation of all refrigerants can be accom lished within )-3 days of work. An
estimated time of one semester is necessary for the ro6ect to be done. 5o
meet the deadline of submission, the grou must work double time es ecially
during weekends and holidays. "cheduling is deemed im ortant to a!oid
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