Purification of air in the refrigeration systems

Air is known as the enemy of any of the refrigeration system. Cleansing whether manual or automatic removal of air and increases the performance of the cooling system.

The air in the cooling system deprives it of the ability to function, and if you do not remove this air can be expensive in terms of operating efficiency and damage to the equipment. Such damage is especially noticeable in the industrial size refrigeration systems commonly used in large refrigeration plants, enterprises of food industry and some chemical plants.

Regardless of whether the system is removed, ammonia refrigerant Freon, the thermal efficiency of such systems will significantly improve when you don't want non-condensable gases (air) is removed. The process of removal of air, odor and color, is called cleansing. Over time, this process becomes more and more automatically. But, it is important to understand, why, where and how to purge the system before relying on automatic cleaning system. Fig. 3.34 shows industrial air purger units.

Air enters the refrigeration system several places:

When the suction pressure below atmospheric conditions, air enters through seals and valve seals.
Air can rush in, if the system is open for repair, coil cleaning or add hardware.
Air can come, when refrigerant truck charging system, or when the butter is added.

Therefore, the accumulated air has a negative impact on system performance, which can be summarized as follows:

This accumulated air isolates transfer surface and effectively reduces the size of the capacitor. To compensate for this reduction in size, the system should work, increasing the pressure and temperature of the refrigerant. Therefore, for removal of air, as quickly and as efficiently as possible is important.
Air in the system can lead to increased wear of bearings and drive motors and encourage more short-term sealing and belts. Moreover, added the head of the pressure increases the likelihood of premature gasket failures. It may also reduce the cost of electricity for operation of the compressor by about 2% for every 1% reduction in compressor performance. Thus, it is important to choose the right size and type purger to work.

The easiest way to determine the amount of air in the cooling system to ensure that the condenser pressure and temperature sender leaving the condenser. Then, these findings should be compared with the standard temperature and pressure for the car.

Example 3.4
If, for example, ammonia temperature 30VC, theoretical pressure condenser should be 1065.2 kPa. If your sensor reads 1199.7 kPa, excess pressure-134.5 kPa. Under this condition, the cost of electricity will increase by 10%, and the compressor capacity is reduced by 5%, as determined by the cost per kWh of energy. For example, if the pressure is reduced by 20 psi and the cost of electricity is $0.05 per kWh, annual savings of more than $2600 per 100 tons.