Common problems of copper tubes during use
1. Copper tube leakage
Copper tube leakage is a fatal defect of air conditioners. Once leaked, all the refrigerant in the air conditioner will leak out, and the air conditioner will lack the "blood" for heat exchange, and therefore fail. The reasons for the leakage of copper tubes are relatively complicated, and the specific reasons are as follows:
① Misuse of defective tubes detected by eddy current flaw detection.
Under normal copper tube production conditions, copper tube eddy current flaw detection not only marks the number of damage points on each copper tube, but also paints the damage points with black marks so that users can identify and pick out this "black tube" during use. In the later installation, some people installed the "black tube" on the product, causing leakage of the air conditioning refrigeration device.
② Processing problems. The main pipe of the air conditioner must go through bending, expansion, flaring, welding and other links in the process of forming the two devices.
In the process of bending, the bent part must be subjected to local force, resulting in local over-stretching, cracking, dark cracks and other problems. Once filled with refrigerant, refrigerant leakage often occurs here.
During the expansion process, the expansion core increases the size of the copper tube by interfering with the inner diameter of the copper tube, so that the outer diameter of the copper tube is fully in contact with the aluminum foil heat sink. During the expansion process, it is very easy for the expansion head to scratch the copper tube, forming a penetration wound and causing leakage of the copper tube; sometimes, due to the large burrs on the inner hole of the aluminum foil, the burrs penetrate the copper tube during the expansion and cause leakage.
③ Leakage caused by poor welding. After the copper tube is inserted into the perforated aluminum foil, the tubes need to be connected, and a small elbow is needed to connect them. In order to make the connection firm, the small elbow and the copper tube are welded together with solder during the production process; the welding method is divided into manual and automatic. During welding, due to the quality of solder, the expansion of the copper tube, and foreign matter on the welding surface, the welding is not solid, forming a virtual weld, causing refrigerant leakage.
2. Cracks in copper tubes
The cracks of copper tubes are mainly concentrated in the expansion and expansion processes of copper tubes. In the production of two devices, the expansion and expansion of copper tubes is a continuous process, which is often completed in one process. There are many reasons for copper tube cracking, and the main reasons are as follows:
① The quality of the copper tube itself. For example, defects on the outer surface, scratches on the inner surface, oxidation on the inner surface, etc., can cause copper tube cracking.
② Human factors. During use, copper tubes are often straightened and cut to size, and chipless cutting is often used for cutting. The surface of the copper tube is relatively soft after heat treatment. When performing chipless cutting, if the cutter is unfavorable or the cutter is too large during cutting, the copper tube will shrink too much or have too many burrs, forming port flash and port hardening, causing cracking during expansion.
