The compressed gas heats up as it is pressurized (orange). The coils on the back of the refrigerator let the hot ammonia gas dissipate its heat. The ammonia gas condenses into ammonia liquid (dark blue) at high pressure. The high-pressure ammonia liquid flows through the expansion valve.
How does refrigeration work step by step?
Can you explain the refrigeration cycle?
The refrigeration cycle, sometimes called a heat pump cycle, is a means of routing heat away from the area you want to cool . This is accomplished by manipulating the pressure of the working refrigerant (air, water, synthetic refrigerants, etc.) through a cycle of compression and expansion.
What are the 4 cycles of refrigeration?
A refrigeration cycle has four major components: the compressor, condenser, expansion device, and evaporator . Refrigerant remains piped between these four components in the refrigerant loop.
How does refrigeration preserve food?
Refrigeration slows bacterial growth . Bacteria exist everywhere in nature. They are in the soil, air, water, and the foods we eat. When they have nutrients (food), moisture, and favorable temperatures, they grow rapidly, increasing in numbers to the point where some types of bacteria can cause illness.
How do fridges make things cold?
Have you ever wondered how your fridge works to keep things cold? Refrigerators use the principles of pressure, condensing and evaporation of a fluid in a closed circuit to remove heat and reduce the temperature inside the fridge .
How does a compressor work in a refrigeration system?
The Refrigeration Cycle
The compressor receives low pressure gas from the evaporator and converts it to high pressure gas through compression , as the name states. As the gas is compressed, the temperature rises. The hot refrigerant gas then flows to the condenser.
How does refrigerant absorb heat?
When liquid refrigerant passes through the expansion valve, its pressure is reduced downstream of the valve. That reduces its temperature, and if it’s colder than its surroundings, liquid refrigerant will absorb heat . The lower pressure also reduces the liquid’s boiling point.
How does inverter refrigerator work?
Inverter refrigerator has a variable speed compressor which adjusts it speed depending on the outside temperature and load on the refrigerator . In an inverter refrigerator the compressor does not starts and stop, but runs at slow speed just enough to maintain the required temperature in the fridge at all times.
How does the evaporator work?
The evaporator works the opposite of the condenser, here refrigerant liquid is converted to gas, absorbing heat from the air in the compartment . When the liquid refrigerant reaches the evaporator its pressure has been reduced, dissipating its heat content and making it much cooler than the fan air flowing around it.
What is the basic refrigeration cycle?
One very important part of all HVAC systems is the basic refrigeration cycle. It contains four major components: the compressor, condenser, expansion device, and evaporator . The system pipes refrigerant through these four components in a loop, giving the cycle its name and keeping your home cool!
Why compressor is used in refrigeration cycle?
The compressor is used in commercial refrigeration by letting the refrigerant run the circuit . The compressor plays a role in the system like a heart in a living creature’s body. The power comes from the electric motor fixed in the system. This process eases the pressure on the refrigerant’s system.
What is evaporator in refrigeration cycle?
An evaporator is used to turn any liquid material into gas . In this process, heat is absorbed. The evaporator transfers heat from the refrigerated space into a heat pump through a liquid refrigerant, which boils in the evaporator at a low-pressure.
Which way does refrigerant flow?
The refrigerant is pushed through the exhaust valve into the condenser. Both the intake and exhaust valves are designed so that the flow of the refrigerant only travels in one direction through the system . Condenser: The condenser removes heat given off during the liquefication of vaporized refrigerant.
How does refrigeration prevent food spoilage?
Refrigeration preserves food by slowing down the growth and reproduction of microorganisms as well as the action of enzymes which cause food to rot . Freezing food slows down decomposition by turning residual moisture into ice, inhibiting the growth of most bacterial species.
What are factors involved in refrigerating a produce?
- Temperature: The temperature at which food is stored is very critical to shelf life. ...
- Moisture: It is recommended to remove moisture when storing foods. ...
- Oxygen: Foods store best when oxygen free. ...
- Light: Light, a form of energy that can degrade the food value of foods.
What is freezing and refrigeration?
In the case of refrigeration, the idea is to slow bacterial action to a crawl so that it takes food much longer (perhaps a week or two, rather than half a day) to spoil. In the case of freezing, the idea is to stop bacterial action altogether. Frozen bacteria are completely inactive.
How is cold generated?
Cold isn’t a thing to be generated . You sense a lack of heat as “cold”. That said, There are spontaneous processes that are also endothermic, meaning they absorb heat. Many Salts, when dissolving in water will also absorb energy (like in an instant ice pack).
How was refrigeration discovered?
1740s. The first form of artificial refrigeration was invented by William Cullen , a Scottish scientist. Cullen showed how the rapid heating of liquid to a gas can result in cooling. This is the principle behind refrigeration that still remains today.
How is a refrigerator built?
Which cycle is used in air refrigeration system?
Air cycle refrigeration works on the reverse Brayton or Joule cycle . Air is compressed and then heat removed, this air is then expanded to a lower temperature than before it was compressed.
How cold can refrigerant get?
The lowest temperature that can practically be achieved in single-stage refrigeration systems is about -40 to -50 ̊F . A single-stage system is limited by the compression ratio of the compressor and the ambient temperature in which it must condense the refrigerant.
Why refrigerant evaporates when it enters in the evaporator?
As its name implies, refrigerant in the evaporator “evaporates”. Upon entering the evaporator, the liquid refrigerant’s temperature is between 40° and 50°F; and without changing its temperature; it absorbs heat as it changes state from a liquid to a vapor .
Where does refrigerant go?
After the condenser, liquid refrigerant travels to the evaporator, located inside the passenger compartment , where it is allowed to expand, removing heat and cooling the evaporator. The fan directs air over the evaporator, then out the air vents in your car.
