How do refrigerators work?

Answer 1

The basic idea behind a refrigerator is very simple: It uses the evaporation of a liquid to absorb heat. . The liquid, or refrigerant, used in a refrigerator evaporates at an extremely low temperature, so it can create freezing temperatures inside the refrigerator.

Answer 2

The vapor compression cycle is used in most household refrigerators. In this cycle, a circulating refrigerant such as freon enters the compressor as a vapor at its boiling point. The vapor is compressed and exits the compressor as a superheated vapor. The superheated vapor travels through part of the condenser which removes the superheat by cooling the vapor. The vapor travels through the remainder of the condenser and is condensed into a liquid at its boiling point. The saturated liquid refrigerant passes through the expansion valve (also called a throttle valve) where its pressure abruptly decreases. The decrease in pressure results in the flash evaporation and auto-refrigeration of a portion of the liquid (typically, less than half of the liquid flashes). The cold and partially vaporized refrigerant travels through the coil or tubes in the evaporator. There a fan circulates across the coil or tubes, and the refrigerant is totally vaporized, extracting heat from the air which is then returned to the food compartment. The refrigerant vapour returns to the compressor inlet to complete the thermodynamic cycle.

Answer 3

Fridges are lined with coils of piping which contain a refrigerant gas. They also have coils of piping on the outside of the casing to the rear of the fridge which work as a heat exchanger. The basic mechanism of a refrigerator works by transforming the refrigerant gas into a liquid and back into a gas to create repeated evaporation of the refrigerant. It is this evaporation process that produces low temperatures. Think about how sweat works to lower body temperature and you have the basic principle in mind. All fridges have a compressor, it is this small engine that you can hear as the fridge cycles on and off. The compressor creates a pressurized environment in part of the fridge. Under pressure the refrigerant warms up and the pressure increases. The heat exchanging coils outside the fridge allow the heat to be dissipated and as it cools the gas turns to liquid form and runs through into the coils inside the fridge which is a comparatively low-pressure area. As the refrigerant expands it evaporates thus absorbing heat and cooling the inside the fridge before repeating the cycle.

Answer 4

In kitchens the world over there is probably a refrigerator in the majority of them. Every 15 minutes or so you hear the motor turn on, and it magically keeps things cold. Without refrigeration, we'd be throwing out our leftovers instead of saving them for another meal.

The refrigerator is one of those miracles of modern living that totally changes life. Prior to refrigeration, the only way to preserve meat was to salt it, and iced beverages in the summer were a real luxury. To properly explain the function of a refridgerator some basic grounding is needed.

The Purpose of Refrigeration

The fundamental reason for having a refrigerator is to keep food cold. Cold temperatures help food stay fresh longer. The basic idea behind refrigeration is to slow down the activity of bacteria (which all food contains) so that it takes longer for the bacteria to spoil the food.

For example, bacteria will spoil milk in two or three hours if the milk is left out on the kitchen counter at room temperature. However, by reducing the temperature of the milk, it will stay fresh for a week or two -- the cold temperature inside the refrigerator decreases the activity of the bacteria that much. By freezing the milk you can stop the bacteria altogether, and the milk can last for months (until effects like freezer burn begin to spoil the milk in non-bacterial ways). Refrigeration and freezing are two of the most common forms of food preservation used today.

Parts of a Refrigerator

The basic idea behind a refrigerator is very simple: It uses the evaporation of a liquid to absorb heat. You'll probably already be aware that when you put water on your skin it makes you feel cool. As the water evaporates, it absorbs heat, creating that cool feeling. Rubbing alcohol feels even cooler because it evaporates at a lower temperature. The liquid, or refrigerant, used in a refrigerator evaporates at an extremely low temperature, so it can create freezing temperatures inside the refrigerator. If you place your refrigerator's refrigerant on your skin (definitely NOT a good idea), it will freeze your skin as it evaporates.

There are five basic parts to any refrigerator (or air-conditioning system): Which works in much the same way.

The Compressor - Heat-exchanging pipes - serpentine or coiled set of pipes outside the unit

The Expansion valve - Heat-exchanging pipes - serpentine or coiled set of pipes inside the unit

The Refrigerant - The liquid that evaporates inside the refrigerator to create the cold temperatures. Many industrial installations use pure ammonia as the refrigerant. Pure ammonia evaporates at -27 degrees Fahrenheit (-32 degrees Celsius).

The basic mechanism of a refrigerator works like this:

The compressor compresses the refrigerant gas. This raises the refrigerant's pressure and temperature, so the heat-exchanging coils outside the refrigerator allow the refrigerant to dissipate the heat of pressurization.

As it cools, the refrigerant condenses into liquid form and flows through the expansion valve.

When it flows through the expansion valve, the liquid refrigerant is allowed to move from a high-pressure zone to a low-pressure zone, so it expands and evaporates. In evaporating, it absorbs heat, making it cold.

The coils inside the refrigerator allow the refrigerant to absorb heat, making the inside of the refrigerator cold. The cycle then repeats.

Answer 5

Evaporation and condensing

Answer 6

you plug them in, switch on and hey presto! Chiled food or drink!

Answer 7

It's called "electricity", if it doesn't work, try plugging in

Answer 8

u put food in it and it keeps it cool