Refrigeration Definition and 78 Threads

Hi guys, I have difficulties understanding the what I need to do in this problem. I have a ideal refrigeration cycle. first part is standard calculations, work of compressor and such. Results are Temperature range between -23 and 60 degrees C. Second part is the one that i do not understand. it...

Got a debate going on with some HVAC supertechs...One contends a sufficient quantity of non-condensables in a refrigeration system (vapor compression & med/hi temp application) will circulate "around" the system. He's saying with the "sufficient quantity", the liquid seal will be lost at the...

Homework Statement I have just done a lab with a refrigeration loop, and I'm unsure of which pressures correspond to which parts of the loop. The hand out says to assume the pressure across the condenser and evaporator are constant, and to use the two pressure guages to measure the pressure...

I know I can easily look this up on Wikipedia, but I chose to use my intuition on this one ;) Tell me if my intuition based approach is correct: You have a compressor which takes a refrigerant gas such as Freon and compresses/decompresses it. I'm imagining it works something like a piston in...

Hi, :smile: So I am learning about how refrigerators work. First I have to show the Carnot cycle and explain why it does not work in reverse - from my understanding, it does not. And then show how it actually works in real life, with the phase transitions, which I am guessing don't exist for...

So I can follow the sequence of operations: the refrigerant enters the compression stage as a saturated vapour(a gas?) and it's compressed raising the temperature of the refrigerant, it gives off some of this heat to the surrounding ambient air, causing a decrease in temperature and an according...

The attached file shows a T-s diagram of a refrigeration cycle . Now let us consider 2 refrigeration cycles as shown in the diagram 1-2-3-4 and 1'-2'-3'-4'. Which one will have a greater C.O.P or greater efficiency ? The first one (1-2-3-4) acts in a lower temperature range , whereas the 2nd...

Homework Statement What is the relationship between the heat absorbed and rejected by the reservoirs and their temperature. If a heat pump is used to transfer heat what is the rate at which heat is added to the hot reservoir in terms of the temperatures of the reservoir and the work done by...

Can someone please explain the picture attached below ? It has been taken from a lab where the supervisor actually failed to tell what is the remote sensing bulb doing attached to a condenser. I would like to know that why is it there and is the wire that is sticking out a capillary tube? If not...

Hi, has anybody worked with heat pumps? I'm recently confused about how the heat pump compressor operates. Does it have a fixed pressure or it actually adjust its pressure automatically to outdoor temperature variation? All my confusion originate from the following problem: Now we have a heat...

Hey, I am trying to determine the importantance and difference of fouling in sizing the evaporator and condenser in a Refrigeration cycle? Thanks, Alexisonsmith

im from India , in my third year of B.E. Mech degree .. course... and my group is planning to do steam jet refrigeration system...as a MINI PROJECT ( Design And Fabrication Project in the syllabus).. the components of the project are - 1. boiler 2. steam nozzle 3. thermocompressor 4...

Hello everyone, I am a first year engineering student and I am really interested in learning about refrigeration (this isn't homework its my own personal interest). I have done a bunch of research but I am a little confused on a couple of points and was hoping that you guys could help me...

Hello, I am a first year engineering student and I have a short question about refrigeration systems. Just want to clarify that this is not a homework question. Yes I do think about things like this in my spare time its just personal interest. I'm taking engineering for a reason :-p. Anyways i...

A 1.2 ton air conditioner has the capacity to freeze 2400 lb of ice at 0°C in a day. What is the equivalent rate of transport of heat in watts? QH(out)= QL(in) + Wi Coefficient of Performance= QL/ (QH-QL) Coefficient of Performance of an Ideal System: TL/ (TH-TL) QL/QH= TL/TH I...

I am NOT referring to laser cooling, the technique for supercooling atoms. The 1980 science fiction novel Sundiver by David Brin describes a kind of spaceship that could fly into the sun. One way described to keep the inside of the ship cool was to concentrate the heat inside the ship...

Hey guys, Just a bit stuck with getting enthalpy values off a table I have in a textbook. If we look at R-22 for example, the textbook gives me different answers than what is available on the net. If I use the values that are given to me on the net I get the correct value. The blue...

A practical question about that cycle: I've just bought a new fridge and looked at the refrigeration cycle for the first time in 5 or so years. Now, i feel that the condenser at the back is quite warm (as it should be) and is being cooled by my room. All good and well. But how does the...

Homework Statement Here is the cycle: I am to assume cold-air standard applies. I need to: a)Draw a T-s diagram b)Find where heat is transferred and work is done c)Calculate the coefficient of performanceHomework Equations COP = 1 / (TH/TL - 1) The Attempt at a Solution For the T-s...

I am doing a project for my thermodynamics class and we have to choose a compressor for a a vapor compression refrigeration cycle that has a heat transfer rate of 1500 btu/h and must maintain 0F in the freezer when the room temp is 90F. I have went through some calculations to find the mass flow...

Please look at the picture on this link of a refrigeration cycle: http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/Dane_Lenaker/img/pics/frigcycle.gif Would the temperature at position 1 be the temperature leaving the evaporator or the temperature entering the compressor? or should they in...

:cry::frown::frown::cry: i am not getting what is the difference between a multistage refrigeration system and a cascaded refrigeration system. i know why staging refrigeration is used. 1# to achieve higher pressure ratio with two or more compressor or multi staging in compressors, thus...

Hey All Suppose ur designing a refrigeration cycle. if u go to the market to choose parts for an 18000BTU/h circuit. The compressor has different ratings according to the entering temp and exit temp, then u have the thermal expansion valve which is also rated in BTU/hr depending on entry and...

hi friends, I wanted to know about the Thermoacoustic Refrigeration.Can u please submit any links or explanation about the topic.Looking forward to your replies.

When a refrigerator has been turned on for some time, steady state refrigeration occurs. This is the normal refrigerator operative state. But what exactly happens? These things are really hard to do research on, since Internet searches, regardless of search query detailing, result in a lot...

I'm working on a project about cooling and heating, and have a couple of questions needing answers/clarification: Entropy in refrigeration: The pV-diagram for the phase change refrigerator is that of the reversed Otto cycle. This cycle contains two adiabatic and two isochoric processes...

Hey, I'm having a bit of trouble with a Thermo problem on a homework assignment. The problem is: 6-138 (Thermodynamics: An Engineering Approach, 5th Edition) The drinking water needs of a production facility with 20 employees is to be met by a bobbler type water fountain. The...

I'm sure most of you have heard of the Einstein Referigeration Cycle . For those who have not I've listed the references for further reading.. http://www.me.gatech.edu/energy/pubs/SLA_2.pdf ok 342 K is about 156 F ,for anyone with an attic , it seems to me that this is the perfect solution to...