Vapour-compression Refrigeration - Lab Report

Added on - 28 May 2020

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LAB REPORTName of StudentInstitution Affiliation1
IntroductionThe experiment which was carried out aimed studying the Vapour-compressionrefrigeration. Both Hilton Refrigeration and the refrigerant R134a were used in during thesession. Refrigeration refers to the process of taking heat from a reservoir with lowtemperatures then dumped to another reservoir with high temperatures to ensure that acold space is always available in the system.There are four processes which make up the refrigeration cycle[ CITATION Qiy14 \l 2057 ].The first process involves the saturated vapour of the refrigerant. The second processincludes the saturated steam leaving evaporator and entering the the thirdprocess the steam which is super-heated is allowed to enter into the condenser[ CITATIONProon \l 2057 ]. Heat is rejected by the vapour which is super-heated and thus condensingat a constant pressure. Once the super-heated steam has condensed, it leaves thecondenser as a saturated liquid. The liquid then is pushed to enter into the expansionvalve, and in that way, it expands to enable the pressure to return to the evaporatorpressure. In that way, the refrigerant passes through the evaporator, and the processcontinues as a cycle[ CITATION Roz12 \l 2057 ].2
By Appling the first law of thermodynamics in the systems which are open.Q+W=((h2h1)+12(c22c12)+g(z2z1))ObjectivesThe objectives of the experiment which was carried out were: to identify the phase andstate of refrigerant as it goes through the processes of the evaporator, compressor, throttlevalve and the condenser. To find out the energy which is transferred to all the systemswhich are mentioned above. To calculate the coefficient of performance of therefrigeration[ CITATION Maj10 \l 2057 ].Experiment Set-UpThe investigations of the coefficient of performance variation were carried out by the useof the Hilton Refrigeration. The changes were to be observed depending on the shaft,electrical and the power indications. The refrigerant R134a was allowed to flow into thecompressor which was from the evaporator which was located at the top of the rig. Therefrigerator is then allowed to condense in the condenser which is around the condenser;there are many coils of cooling water[ CITATION Maj10 \l 2057 ]. The vapour from therefrigerantrejects all the heat making it condense at the condenser coil. This process ofvaporising and condensing continues in a cycle[ CITATION Chr15 \l 2057 ].3
MethodThroughout the experiment session pressure in the condenser was kept constant at950KNm-2.This was aimed at applying a steady flow of other conditions. The load in theevaporator was varied between 400W to 800W by the use of the input control of theevaporator[ CITATION Eri11 \l 2057 ]. The pressure of the condenser would changeaccording to the changes which were made in the evaporator load. The rate of water flowand the spring balance was in most cases replaced simultaneously to keep the pressure onthe condenser at 950KNm-2.The water flow transducer was used to adjust the rate atwhich water was flowing. It was a must that the spring balance had to line with thearrow(6).The readings of the water flow and the refrigerant were read from theflowmeters which were at Rig and the also the reading on the spring balance was alsotaken. The evaporator pressure was read from the evaporator pressure dial[ CITATIONRur12 \l 2057 ].All the measurements of temperature ware also keenly recorded which sixin total were. There were variations which were done to the selector switch such that itchanged from 1 to 6 and the temperature readings were recorded. The last measurementwhich was to be recorded was to be taken from the motor input[ CITATION Mah16 \l 2057 ].4
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