To put it simply there are 3 steps by which a refrigerator or a fridge works:
1.Cool refrigerant is passed around food items kept inside the fridge.
2.Refrigerant absorbs heat from the food items.
3.Refrigerant transfers the absorbed heat to the relatively cooler surroundings outside.
Most people would not know what to do without a refrigerator, as there are few things that can soothe their dried-out throat as much as a glass of chilled water.
Although there were techniques people used in ancient times to provide themselves with cold water, it was certainly not as easy as opening a door at home and taking a bottle of ice-cold water. Even if they could get cold water to drink, they certainly had nothing to keep their food fresh for days or even weeks.
Fortunately, we have a little thing that does all these things for us – a fridge!
In this article we will take a look at the science of a refrigerator, in particular the different parts of a refrigerator and how they actually work together to preserve our food for longer periods of time.
Refrigerator working principle
The principle of refrigeration and cooling is very simple: it involves removing heat from one region and depositing it in another. When you pass a low-temperature liquid close to objects that you want to cool, heat from those objects is transferred to the liquid, which evaporates and takes away the heat in the process.
You may already know that gases heat up when you compress them and cool down when they are allowed to expand. That’s why a bicycle pump feels warm when you use it to pump air into a tire, while sprayed perfume feels cold.
The tendency of gases to get hot when they are compressed and cold when they expand, along with the help of some refined devices, helps a refrigerator cool the stuff stored in it.
Parts of a fridge
A refrigerator consists of several key components that play a crucial role in the cooling process:
Internal Parts Of A Refrigerator And Its Functions
A compressor is the main part of a refrigerator. It is the heart of the refrigerator and does the job of cooling. The compressor consumes most of the electricity. It’s located at the back of the refrigerator and is run by an electric motor. Without this part, your refrigerator is nothing but a wardrobe.
Refrigerant is a cooling liquid that spreads inside the refrigerator and carries out the cooling part. The compressor runs this refrigerant with the help of an electric motor. The refrigerant keeps on recirculating through all the internal parts of the refrigerator on the loop.
The condenser is a copper tubing located at the back of the fridge. The heat produced in the refrigerant needs to be absorbed by something. That is what the condenser does. There are fans placed above the condenser unit to draw air over the condenser coils.
The evaporator is a heat exchanger made of aluminum or copper tubing. The only purpose of the evaporator is to absorb the unwanted heat from the food. The refrigerants absorb the heat from the food to be cooled in the evaporator. Then it is sucked by the compressor, and the cycle keeps on repeating.
To control the temperature inside the refrigerator, there is a thermostat, which is connected to the evaporator directly. There is a round knob inside the refrigerator, using which you can control the thermostat setting.
When the desired temperature is reached, it stops the electricity supply automatically to the compressor. When the temperature falls to a certain level, then it restarts, sending power supply to the compressor.
Defrosting the refrigerator helps to remove all the excess ice that gets build up in the freezer. It can be done both manually by the thermostat button or automatically by the system comprising of the electric heating and timer.
The diffuser in a refrigerator helps to regulate the flow of cold air from the freezer compartment into the refrigerator compartment. It has a temperature sensor, which you can control with the refrigerator thermostat.
When the diffuser senses that the air in the refrigerator has gotten too warm, it opens the vents between the two compartments.
External Parts Of A Refrigerator And Its Functions
The food items that are to be kept at the freezing temperature are stored in the freezer. The temperature of a freezer compartment is below zero degrees. It is ideal if you want to make ice cream, frozen foods, or beverages.
This is the place where you will find ice for your lemonade.
The door gasket is a flexible seal that attaches to the outer edge of the refrigerator door. It forms an airtight seal around the door when closed. The door gasket prevents warm, moist air from leaking into the refrigerator compartment.
The light switch turns the refrigerator lights on and off. As soon as the refrigerator door opens, it supplies power to the light, and it turns on, and when the door is closed, the power supply gets interrupted, and it turns off. This way, it saves electricity too.
Shelves of a refrigerator are mostly made of toughened glass. The shelf is the place where you keep your stuff. They are very sturdy and can hold a lot of weight.
The refrigerator door has several smaller subsections to keep bottles, eggs, butter, and other stuff. It maximizes the space in the fridge. The door covers the front of the refrigerator cabinet.
The drain pan collects the water from the defrost cycle. It is located next to the compressor, in the machine compartment. The defrosting process melts frozen ice, and the water that drips during the process is collected in a tray and then is routed to the drain pan. The drain pan collects all the condensate.
High-end side by side refrigerators, double/triple door refrigerator comes with this water dispenser. It lets you drink water without even opening the refrigerator door. Although it takes up the internal space by a little margin, it’s good to have this feature.
Refrigerator water filter
The refrigerator water filter is to filter the water of the refrigerator water dispenser, so that the water that people drink is healthy and safe, without any harmful substances in drinking water, the refrigerator filter needs to be replaced in 3~6 months or 300 gallons of water. The refrigerator filters sold by the refrigerator manufacturers are too expensive, you can buy a water filter from GlacialPure, which is much cheaper than the water filter from the refrigerator manufacturer. The use and function are exactly the same. Most refrigerator models on the market. Available at GlacialPure such as Samsung (DA29-00020B) and GE (MWF).
Refrigerator function: How does a refrigerator work?
A refrigerator works in the following steps:
The compressor compresses the refrigerant gas. The compressed gas heats up as it is pressurized.
The coils on the back of the refrigerator let the hot refrigerant gas dissipate its heat. The refrigerant gas condenses into liquid at high pressure.
The high-pressure liquid flows through the expansion valve.
The liquid immediately boils and vaporizes, its temperature dropping to about -25°F, as the cold gas flows through the expansion coils (inside the refrigerator) it makes the inside cold by absorbing heat.
The low pressure refrigerant gas is sucked up by the compressor, and the cycle repeats.
Now, let’s discuss the working of a refrigerator in more detail.
The compressor, which is a critical component of the refrigerator, compresses the refrigerant gas. As it undergoes high pressure, the gas heats up. Now, this gas transports to the condenser coils (thin radiator pipes) located at the back of the fridge, where the coils help dissipate its heat so that it becomes cool enough to condense and convert back into its liquid phase.
Because the heat collected from the food items is given off to the surroundings via the condenser, it feels hot to the touch.
The high pressure liquid that we have now flows through the expansion valve. Think of the expansion valve as a small hole. On one side of the hole is high-pressure refrigerant liquid. On the other side of the hole is a low-pressure area (because the compressor is sucking gas out of that side).
After passing through the expansion valve, the liquid experiences a drop in the pressure. As a result, it becomes a cool (to the tune of -25°F) gas.
When this cool gas flows through the expansion coils (installed inside the fridge), it absorbs heat and therefore make the insides of the fridge cold.
This low pressure refrigerant gas is once again sucked by the compressor, and the whole cycle repeats, keeping the contents of a refrigerator perpetually cold.