How does a refrigerator work?
In the summertime, have you ever gotten out of a swimming pool and then felt very cold standing in the sun? That’s because the water on your skin is evaporating. The air carries off the water vapor, and with it some of the heat is being taken away from your skin. This is similar to what happens inside older refrigerators. Instead of water, though, the refrigerator uses chemicals to do the cooling. There are two things that need to be known for refrigeration. 1. A gas cools on expansion. 2. When you have two things that are different temperatures that touch or are near each other, the hotter surface cools and the colder surface warms up. This is a law of physics called the Second Law of Thermodynamics. Old Refrigerators If you look at the back or bottom of an older refrigerator, you’ll see a long thin tube that loops back and forth. This tube is connected to a pump, which is powered by an electric motor. Inside the tube is Freon, a type of gas. Freon is the brand name of the gas. This g
Ironically, refrigerators keep things cold because of the nature of heat. The Second Law of Thermodynamics essentially states that if a cold object is placed next to a hot object, the cold object will become warmer and the hot object will become cooler. A refrigerator does not cool items by lowering their original temperatures; instead, an evaporating gas called a refrigerant draws heat away, leaving the surrounding area much colder. Refrigerators and air conditioners both work on the principle of cooling through evaporation. A refrigerator consists of two storage compartments – one for frozen items and the other for items requiring refrigeration but not freezing. These compartments are surrounded by a series of heat-exchanging pipes. Near the bottom of the refrigerator unit is a heavy metal device called a compressor. The compressor is powered by an electric motor. More heat-exchanging pipes are coiled behind the refrigerator. Running through the entire system is pure ammonia, which e
In the summertime, have you ever gotten out of a swimming pool and then felt very cold standing in the sun? That’s because the water on your skin is evaporating. The air carries off the water vapor, and with it some of the heat is being taken away from your skin. This is similar to what happens inside older refrigerators. Instead of water, though, the refrigerator uses chemicals to do the cooling. There are two things that need to be known for refrigeration. • A gas cools on expansion. • When you have two things that are different temperatures that touch or are near each other, the hotter surface cools and the colder surface warms up. This is a law of physics called the Second Law of Thermodynamics. Old Refrigerators If you look at the back or bottom of an older refrigerator, you’ll see a long thin tube that loops back and forth. This tube is connected to a pump, which is powered by an electric motor. Inside the tube is Freon, a type of gas. Freon is the brand name of the gas. This gas
Response #: 1 of 1 Author: dipper Text: Most common refrigerators have four major parts to its refrigeration system — a compressor, condenser, expansion valve, and evaporator. In the evaporator section, a refrigerant (up until very recently it has been “DuPont’s Freon (TM)-12”, or dichlorodifluoromethane) is vaporized, and heat is absorbed through the inside walls of the refrigerator, making it cold inside. DuPont’s Freon (TM)-12 boils at -6.6 C (about 20 F) when pressurized at 35.7 pounds per square inch, so evaporator temperature is maintained at or near that temperature if the refrigerator is working properly. In the next stage, an electric motor runs a small piston or Wankel compressor (some new compressors are vane type) and the DuPont’s Freon (TM)-12 is pressurized. That raises the temperature of the DuPont’s Freon (TM)-12. The resulting super– heated, high-pressure gas (it is still a gas at this point) is then condensed to a liquid in an air-cooled condenser. On most refrigera
