Automotive conditioning system Is to achieve cabin air cooling, heating, ventilation, and the air purification means . It can provide the passenger a comfortable driving environment, reducing operator fatigue and improve traffic safety. Automotive air conditioning system but relatively poor working conditions, can easily cause member, the pipe Is broken and loose connections, the refrigerant leakage occurs, the site of a leak often Table 9-1.
Commonly used Automotive air conditioning system leak inspection method Is as follows:
(1) Method soap foam leak
the refrigerant leak site Will also bleed refrigeration lubricants, and therefore if found somewhere traces of oil, direct palpation or application of hand wiping with a clean cotton yarn, if rubbed also to oil exudation after, the leak can be determined Automotive air conditioning system, since if there Is no oil exudation wipe, available soapy water, soapy water evenly and completely brush possible leak site, then Carefully observed, such as bubbles, it can determine the leak Automotive air conditioning system.
(note: examination method can not soapy water and soap coating should not leak observed region compressor, a condenser and an evaporator, the main portion of the pipeline leak may be checked, leak in the high pressure line Is not in operation and air-conditioning operation can be checked, but the low-pressure line leak the air conditioner Is not in operation before the investigation.)
(2) pressing method leak
first, as shown in Figure 9-2 the pressure hose connected to the high pressure maintenance valve, a low pressure hose connected to the low pressure service valve.
Since the compressed air in the water Will cause ice blocking phenomenon in the expansion valve, the leak can not be used, common technical nitrogen, the advantage Is noncorrosive , moIsture-free, and inexpensive, the leak detection process Is a high pressure nitrogen bottle by vacuum table under reduced pressure, infusion of about 1.5MPa nitrogen after the refrigeration system, with soap and evenly coated in the joints and welding systems, Carefully observe whether there Is a bubble, leakage of sound, hairNow leaks should make a mark and make timely treatment and then go to check welds and other joints, must be Carefully checked and double-checked 3-5 times until the complete elimination of leakage. After inspection, shall try leak, air conditioning and refrigeration systems Is holding pressure 24 ~ 48h. If the pressure does not decrease, then the cooling system passing seal, if the pressure Is reduced significantly, then there Is not found a place, must then leak, until the complete elimination of retentate
( 3) leak vacuum method
refers to a leak detection method in a vacuum after evacuation of the refrigeration system, the system remains in a vacuum state period of time (at least 60min), then the vacuum pressure in the system was observed if the table pointer movement (i.e., whether the pointer changes) a leak detection method. The vacuum indicated no change, then the system has no leaks, as indicated with a vacuum pick-up, then the system has a leak.
(note: It Is noted that, with thIs method of leak detection, can be described refrigeration system leaks, but can not determine the exact location of leakage)
(4) fluoro leak charge
fluoride charge Will leak to the front after several leak, leak detection method Is to charge the fluorine manifold pressure high table are connected to the compressor, a low pressure service valve attached to the intermediate refrigerant bottle, and then manually open the high and low pressure valve and the refrigerant bottle, added Freon refrigerant to the refrigeration system, when the pressure reached 0.1MPa, respectively, high closed manually, and the low pressure refrigerant canIster valve, the system pressure protection hours. If the system pressure constant, it means that the system does not leak. If the system pressure drops, it indicates a leak system, thIs time to use a halogen lamp or an electronic leak leak leak site and then find to trap.
(5) an ultraviolet inspection lamp fluorescent dyes
UV light causes fluorescent dye molecules in the ultraviolet laser emits yellow or yellow-green phosphor, an ultraviolet fluorescent lamp leak leak detection method Is to press a fluorescent leak detection dyes into the refrigeration system, there Is irradiation with ultraviolet light, the system leak, Will yellow or yellow-green light, a fluorescent molecule may remain valid for two years.
(6) Leak dye solution
ThIs Is a vehicular air-conditioner can be placed in a solution of colored dye in the leak It Will be dIsplayed. Also part Is colored, some manufacturers supply the red dye-containing refrigerant, the refrigerant which Is installed in a vehicle air conditioner normal way. There are other light black dye solution or dye tracer solution can help pinpoint small leaks can be dIsplayed around the exact position of the colored film layer of the dye leakage points, based on the dye used, the film may be orange or yellow. Once the dye Is drawn into Automotive air conditioning system, it can remain in the system to be cleaned up, but did not affect the operation of the system. Figure 9-3 Is a refrigerant detection dye component.
It can be seen, the Car air-conditioning leakage inspection and maintenance Is very important! Recommended that the majority of Cardholders or owners who regularly Automotive air conditioning system or leak component inspection, as well as sterilization and deodorization maintenance!