Cleaning method of condenser dirt in central air conditioning
It is easy for the condenser to form scale in the pipeline after long-term use. If it is not treated in time, the scale will affect the heat exchange effect, cause the condensing temperature of the unit to rise, and then reduce the cooling capacity and increase the power consumption of the unit, as shown in the figure below. Therefore, the condenser should often remove the scale.
There are two ways to prevent and remove scale
1. Physical and mechanical descaling method: physical and mechanical descaling is a method of descaling the condenser of steel cooling pipe with soft shaft blasting machine, especially suitable for vertical shell and tube condenser.
The operation method is as follows:
1. Remove the refrigerant from the condenser.
2. Close all valves connecting condenser and refrigeration system.
3. The cooling water of condenser is supplied normally.
4. The roller brush connected with the soft shaft of the shotgun is used to remove the scale from top to bottom in the vertical pipe of the condenser. The heat generated by the friction between the roller brush and the pipe wall is cooled by the water inlet from the soft shaft, and the scale, rust and other dirt removed are washed into the pool.
In the process of descaling, the roller brush with appropriate diameter is selected according to the scaling thickness of condenser, the corrosion degree of tube wall and the service life. However, the diameter of roller brush selected in the first descaling is smaller than the inner diameter of cooling tube to prevent damage to tube wall. Then, the roller brush close to the inner diameter of cooling tube is selected for the second descaling, and the condenser can be removed by these two descaling More than 5% of scale and rust. Generally, the scale can be cleaned by nylon brush, and the hard scale can be cleaned by copper wire brush or steel wire brush.
This kind of physical descaling method is to use the rotation and friction of the roller brush in the process of rotating in the cooling pipe to remove the scale and rust in the cooling pipe of the condenser. After the descaling is completed, all the water in the condensate pool is pumped out, the scale and rust removed from the bottom of the pool are cleaned up, and the water is injected again.
2. Chemical pickling descaling method: the prepared weak acid descaling agent is used to clean the condenser, so as to make the scale fall off and improve the heat transfer efficiency of the condenser.
The operation method is as follows:
The descaling solution is prepared in the pickling tank, and the pickling pump is started to make the descaling solution circulate in the condensing tube of the condenser. Generally, the scale is basically removed after less than 4 hours.
After stopping the pickling pump, use the blasting machine to clean the wall of the condenser tube again to clean the scale and rust.
Then clean the residual detergent solution in the pipe repeatedly with clean water until it is completely clean. The chemical pickling method is suitable for vertical and horizontal shell and tube condensers.
The significance of descaling and energy saving:
Once the condenser has scale, the thermal resistance of heat conduction will increase, so the thermal resistance will increase, and the value of heat transfer coefficient will decrease. Because the condensation temperature is inversely proportional to the heat transfer coefficient, the condenser temperature will increase, and the condensation pressure will also increase correspondingly. The more serious the condenser scale is, the more significantly the condensation pressure will increase, which will increase the power consumption of the refrigerator and cause the operation of the refrigeration system The power consumption of rotating equipment increases correspondingly, resulting in the waste of electric energy.
