Once the refrigerant leaks in the cold storage, it will lead to the paralysis of the refrigeration system, and it will cause suffocation, poisoning, pollution, fire and other accidents. There are not a few cold storage incidents in previous years, which makes some people talk about the refrigerant leakage in cold storage a bit "talking about the fear of the tiger". Therefore, in this issue, we will share with you the causes and treatment methods of refrigerant leakage in cold storage.First, three reasons for the leakage of cold storageReason 1: The quality and thickness of aluminum bars.As we all know, aluminum tubes are mainly used in the refrigeration system of cold storage from 10℃ to -45℃, and they are a better choice for evaporators in all kinds of food freezing and refrigeration systems. Inferior aluminum platoon is a hidden danger to the safety of cold storage, and high-quality aluminum platoon has strict requirements on the wall thickness of aluminum platoon, which must reach a certain thickness.The common thickness of aluminum pipes in cold storage includes 1.6mm, 1.8mm and 2 mm. Generally, it can't be lower than these thicknesses. Through professional experiments and continuous engineering case practice, it is proved that the 2mm thick aluminum exhaust pipe has good air tightness, high safety factor and strong pressure resistance, which can ensure the normal operation of the refrigeration system. On the one hand, the products with aluminum exhaust pipe thickness of 1.6mm, 1.8mm or even less than 1.6mm will have the problem of natural leakage of refrigerant because of poor air tightness.The hidden trouble of thin aluminum row can not be detected when nitrogen is pressed to detect leakage. On the one hand, in the process of hot fluorination frost, when hot and cold gases are exchanged, the expansion coefficient increases, and the pressure generated is 10 times greater than usual. If the thickness of aluminum exhaust pipe is too thin, the phenomenon of "tube explosion" will occur because of too high pressure. If the tube bursts, the refrigerant will inevitably leak. The leakage of refrigerant will cause the compressor to be damaged, the refrigeration system to be paralyzed, and the items stored in the cold storage to be polluted.Reason 2: Problems of welding process points of aluminum bar.Many treatment details of aluminum bus will directly affect whether the refrigerant will leak, including welding technology, surface treatment technology, thickness of pipe wall, material selection, etc., especially welding technology.There are many processes for welding metals in the market, such as fusion welding, resistance welding, gas welding, brazing, plasma arc welding, electron beam welding, vacuum diffusion welding, tungsten pulse argon arc fusion welding and so on. The welding processes suitable for aluminum (aluminum alloy) welding mainly include gas welding and tungsten pulsed argon arc welding.Gas welding refers to a welding method that uses the flame generated by the mixed combustion of combustible gas and combustion-supporting gas as the heat source to melt the weldment and welding material to achieve atomic bonding. Mainly used for welding thin steel plates, low melting point materials (non-ferrous metals and their alloys) and other materials, including aluminum products.The advantages of gas welding are: simple equipment and flexible operation; Good adaptability to the welding of cast iron and some non-ferrous metals; Gas welding can play a greater role in places where power supply is insufficient.The disadvantages of gas welding are: low production efficiency; After welding, the workpiece is deformed and the heat affected zone is large, which leads to piles of welding slag and messy surface, and it is difficult to realize automation.When welding aluminum bus by gas welding, the combustion-supporting gas is mainly oxygen, and the combustible gas is mainly acetylene, liquefied petroleum gas, etc., so the flame has low thermal power, large heating area, relatively dispersed heat, the weldment is easy to deform, and the temperature is high in the welding process. After welding, the weld metal not only has dispersed crystals and loose structures, but also makes the aluminum at the welding mouth chemically react to change molecules and produce alumina inclusions, which will produce defects such as pores and cracks. So that that aluminum bar has a potential air tightness problem; poor air tightness of the aluminum bar product will directly cause refrigerant leakage in the cold storage, and the refrigerant leakage can lead to paralysis of the whole refrigeration system; and if relevant goods are stored in the cold storage, the joint loss is immeasurable. At the same time, there is a risk that solder remains in the aluminum exhaust pipe during the welding process, which will seriously lead to the blockage of the exhaust pipe and the abnormal operation of the refrigeration system.Therefore, it is generally recommended to use pulsed argon tungsten arc welding. If gas welding is used, it is necessary to ensure the mature and standardized operation of welding.Reason 3, aging of valves and other parts of cold storage.The reason for the leakage of cold storage is not only the operation mistakes of a few people, but also the equipment itself: in the normal use process, the leakage accident caused by the aging of the equipment that has not been repaired for a long time is the equipment failure; Valve leakage, usually due to the loose axis of the valve, poor air tightness, ammonia leakage along the axis; Weld aging, after long-term use, weld aging on some pipelines, resulting in ammonia leakage; The flange gasket is aging, and the equipment oil in the pipeline is easy to corrode the rubber gasket in the flange, causing the gasket to age and leak.Although there are few safety accidents such as leakage in fluorine system, it is impossible to prevent the troubles caused by the use of inferior valve parts to the cold storage project. Generally speaking, inferior valve parts are made of materials with incorrect composition and high impurity content (many of which are recycled waste products). Strength and sealing are very important for valve parts. Inferior valve parts often reduce costs and make profits by using seals from informal manufacturers and reducing the wall thickness of materials.The most obvious difference between inferior valves and high-quality valves is whether they are leaked. Using inferior valves will cause a lot of potential safety hazards and system waste, but it will cause downtime for users of cold storage and cannot guarantee food quality. In addition, it may cause safety accidents.