refrigerators
Created | Updated Jan 28, 2002
The common refrigerator, otherwise known as the fridge, is a wonder and a mystery to most people ofthe world. (those who live in countries technologically advanced enough to have them) Really, they operate on a few very simple principles
_______________
_______2a ____I I_____2b_______ ____
I _____________ 2 ____________ I I
I I I______________I I I I
__I_I___ I I I HIGH PRESSURE
I I I I I
I 1 I I I __I__
I_______I I 4 I I
I I I I I
I I _______________ I I I LOW PRESSURE
I I__________I I___________I I I
I_____3a_____ 3 _____3b______I __I__
I_______________ I
1. this is the compressor
2. this is the condenser
3. this is the evaporator
4. this is the needle valve
a) keeps the high pressure
on the high pressure side
and the low pressure on
the low pressure side.
EXPLANATION:
Ok, this is how it works. inside the refrigeration unit (refrigerator) there is a gas called a refrigerant. Now the thing that makes this gas work so well, is its very low boiling point. this means that at room temperature and pressure, it is a gas. now, in a refrigerator, there are two different sides. actually 4 different sides. two on the high pressure side, and two on the low pressure side. Dont worry, it's really not that complicated. ok, lets start on side 2b(to the right of the condenser. in this area, we have high pressure liquid refrigerant. now, in this stage the refrigerant isnt cold, it's more orless room temp, but its super concentrated (a liquid). so as the compressr pushes it through the needle valve (number 4) it enters the low pressure side, or side 3b. so now we have a low pressure liquid, but since its not hot, it stays a liquid. Then, it enters the evaporator, (number 3) where the pressure gets even lower because there is more space for it to spread out. now have you ever boiled a pot of water? the boiling poiint of water is 212 degrees fahrenheight, right? why doesn't it get hotter?? because as the water turns to steam, the steam removes heat (steam is hot, isnt it?) also, as you go up into the mountains, water boils at a lower temperature. the same thing lets refrigerators work. so as the low pressure, low temp. liquid refrigerant enters the evaporator, it boils. same as water in a pot, and as it turns to gas, the gas removes heat from the evaporator coils. then, a fan blows incoming air over these coils, cooling it off. now the gas is at low pressure, and its hot, on side 3a. Ok, you say, so how do ou get rid of the heat? well, that's where the compressor comes back into play. the compressor (number 1) draws this warm gas in, and compreses it, squishing the molecules really really close together. this makes the gas hotter, really hot in fact. the amount of heat hasnt changed, just how much heat for the volume. ok, now we come back to side 2a. here we have high pressure, high heat. Now, do you guys remember biology class, where you lerned about diffusion and concentration gradients? well, thattts how refrigerators work too. now, everything in the universe is trying to be equal. (I wish we could be that way too) so when something is sitting on the table and it's hot, it gets cool after awhile, right? ok, when there is a big difference in temperature, the heat will flow from the side with high concentration to the side with low concentration. (the same thing happens with pressure. these two things together create wind on earth, together with the coriolis effect -spinning of the earth-) ok, so were on side 2a. now as the high pressure, high heat ggas is pushed into the condenser, we have more coils. now, in here the pressure doesnt drop, , but the line is really small, and there are thin metal fins attached to the line. heat travels through metal very well, so air is blown through these evaperator coils, and the air since it is at a much lower temp, draws the hat away from the fins, and metal tube, and high pressure high heat gas refrigerant. now, inside of the condenser, as the amount of heat, and energy of the molecules of the refrigerant drops, the molecules get closer and closer together, and it turns back into a liquid, and were back at side 2b, right back where we started. (so now i have explained why warm air comes out of the bottom of the fridge. that's all the heat from the food you just put in there. dont you feel more at one with the universe now? I know I do)
_______________
_______2a ____I I_____2b_______ ____
I _____________ 2 ____________ I I
I I I______________I I I I
__I_I___ I I I HIGH PRESSURE
I I I I I
I 1 I I I __I__
I_______I I 4 I I
I I I I I
I I _______________ I I I LOW PRESSURE
I I__________I I___________I I I
I_____3a_____ 3 _____3b______I __I__
I_______________ I
1. this is the compressor
2. this is the condenser
3. this is the evaporator
4. this is the needle valve
a) keeps the high pressure
on the high pressure side
and the low pressure on
the low pressure side.
EXPLANATION:
Ok, this is how it works. inside the refrigeration unit (refrigerator) there is a gas called a refrigerant. Now the thing that makes this gas work so well, is its very low boiling point. this means that at room temperature and pressure, it is a gas. now, in a refrigerator, there are two different sides. actually 4 different sides. two on the high pressure side, and two on the low pressure side. Dont worry, it's really not that complicated. ok, lets start on side 2b(to the right of the condenser. in this area, we have high pressure liquid refrigerant. now, in this stage the refrigerant isnt cold, it's more orless room temp, but its super concentrated (a liquid). so as the compressr pushes it through the needle valve (number 4) it enters the low pressure side, or side 3b. so now we have a low pressure liquid, but since its not hot, it stays a liquid. Then, it enters the evaporator, (number 3) where the pressure gets even lower because there is more space for it to spread out. now have you ever boiled a pot of water? the boiling poiint of water is 212 degrees fahrenheight, right? why doesn't it get hotter?? because as the water turns to steam, the steam removes heat (steam is hot, isnt it?) also, as you go up into the mountains, water boils at a lower temperature. the same thing lets refrigerators work. so as the low pressure, low temp. liquid refrigerant enters the evaporator, it boils. same as water in a pot, and as it turns to gas, the gas removes heat from the evaporator coils. then, a fan blows incoming air over these coils, cooling it off. now the gas is at low pressure, and its hot, on side 3a. Ok, you say, so how do ou get rid of the heat? well, that's where the compressor comes back into play. the compressor (number 1) draws this warm gas in, and compreses it, squishing the molecules really really close together. this makes the gas hotter, really hot in fact. the amount of heat hasnt changed, just how much heat for the volume. ok, now we come back to side 2a. here we have high pressure, high heat. Now, do you guys remember biology class, where you lerned about diffusion and concentration gradients? well, thattts how refrigerators work too. now, everything in the universe is trying to be equal. (I wish we could be that way too) so when something is sitting on the table and it's hot, it gets cool after awhile, right? ok, when there is a big difference in temperature, the heat will flow from the side with high concentration to the side with low concentration. (the same thing happens with pressure. these two things together create wind on earth, together with the coriolis effect -spinning of the earth-) ok, so were on side 2a. now as the high pressure, high heat ggas is pushed into the condenser, we have more coils. now, in here the pressure doesnt drop, , but the line is really small, and there are thin metal fins attached to the line. heat travels through metal very well, so air is blown through these evaperator coils, and the air since it is at a much lower temp, draws the hat away from the fins, and metal tube, and high pressure high heat gas refrigerant. now, inside of the condenser, as the amount of heat, and energy of the molecules of the refrigerant drops, the molecules get closer and closer together, and it turns back into a liquid, and were back at side 2b, right back where we started. (so now i have explained why warm air comes out of the bottom of the fridge. that's all the heat from the food you just put in there. dont you feel more at one with the universe now? I know I do)
