Working of a Refrigerator

Answer 1

The parts of a hermetic (sealed) reciprocating compressor is as follows; motor, crankshaft, bearings, valves, and pressure relief valve and piston(s). there are other smaller parts that can be named but these are the main players.

The hermetic scroll compressor is a little different than the reciprocating compressor because it uses an orbiting scroll and a stationary scroll to compress the refrigerant instead of pistons. This is why a scroll compressor cannot run "backwards". The scroll compressor also has an oil pick up tube which differs from a reciprocating compressor.

Now a "semi-hermetic" compressor is build like a small engine. It has an oil pump, reed valve plate, unloaders, pistons, bearings, etc.

A screw compressor is in a class all to itself.

Answer 2

The lowest part.
The coldest part of a fridge is at the very bottom, or the lowest part of it.

AnswerThe freezer aside, it makes sense that the colder air will be at the bottom in the back, but if the unit is set very cold, food on the top shelf, the place nearest the duct that conveys cold (freezing) air down from the freezer compartment into the main body, will freeze when other food in the middle or at the bottom won't. This from personal experience. There is more to this question (and answer) than meets the eye. The refrigerator is a dynamic environment. Use of the discussion forum is requested. Urged. Please.

Answer 3

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 refrigerators, the compressor is on the bottom and the
condenser coils are on the rear of the refrigerator. From the condenser, the
liquid DuPont's Freon (TM)-12 flows through an expansion valve, in which its pressure and temperature are reduced the conditions that are maintained in the evaporator.
The whole process operated continuously, by transferring heat from the
evaporator section (inside the refrigerator, to the condenser section (outside
the refrigerator), by pumping the DuPont's Freon (TM)-12 continuously through the system described above. When the desired temperature is reached, the pump stops and so does the heat transfer. Freezers and air conditioners work exactly the
same way. The difference is mostly in their compressor capacities and
differing pressures. For example, to maintain -20 F (-29 C), as with a frozen
food freezer, DuPont's Freon (TM)-12 must maintain a pressure of 15.3 pounds per square inch in the evaporator section. Because of the concerns regarding
chlorofluorocarbons in the past several years, new refrigerators do not use
DuPont's Freon (TM)-12 any more. In fact, in years gone by (I will show my age here),
refrigerators used Ammonia as a refrigerant! New materials to replace DuPont's Freon (TM)-12 have been developed, and are currently being developed. Now to totally
confuse you, there are some refrigerators that use the absorption system of
heat transfer. These refrigerators are operated usually by natural or LP gas.
In these refrigerators a strong solution of ammonia in water is heated by a
gas flame in a container called a generator, and the ammonia is driven off as
a vapor. The ammonia vapor then goes into a condenser, where it is changed to
its liquid state. The ammonia then flows into the evaporator, just like a
conventional system. But, instead of the gas being brought into a compressor
after leaving the evaporator, the ammonia gas is reabsorbed in the partially
cooled, weak solution returning from the generator, making it a strong ammonia
solution, again. This process happens in another small container called, you
guessed it, the absorber. From there this concentrated solution flows back to
the generator to complete the cycle. This is the type of refrigerator that is
seen most often in campers and RV's.

Answer 4

The main components of a fridge are. The compressor. The condensor. The dryer. Capillary tube. Evaporator. Suction tube.