How to deal with the refrigerant leakage of precision air conditioner in computer room

How to deal with the refrigerant leakage of precision air conditioner in computer room

As we all know, the power density of equipment in the computer room is high, so the volume heat is high. The computer room for exchange and data still needs to be continuously cooled by air-conditioning compressors to meet the environmental temperature requirements of communication equipment. The refrigerant is used for indoor and outdoor heat exchange to avoid the operation of the air-conditioning compressor. Due to the large number of welds on the left and right sides of the precision air-conditioning evaporator in the computer room, there may be more leaks. The leakage of the precision air-conditioning refrigerant is also common. The main reason is that the employees of the air conditioner factory have poor welding skills. They put the welding rod on the welding joint without burning the copper tube red (the temperature did not reach 600℃～700℃), and the copper tube and the solder could not be fused together. Caused by welding joints, slag, and uneven leakage, let's take a look at how to fix these leak points of air-conditioning refrigerant.

For the newly installed air conditioner in the computer room, close the stop valve of the outdoor unit to eliminate the indoor unit atmosphere. The leaking sound of the indoor unit evaporator can occasionally be heard with ears. It can be seen that the air conditioner leaks. The solder joints of the evaporator are beyond negligible. If the evaporator leaks, please remove it and weld it to prevent the heat flame from deforming the plastic shell of the evaporator. I have no choice but to explain to the user. The assembly method is:

　　 1. Identify the missing points and mark them.

　　2. If there is another refrigerant in the refrigeration system, store the refrigerant in the outdoor unit first.

　　 3. Use two 8-inch or 10-inch wrenches to remove the connection lock nut of the indoor unit, and remove the electrical box on the right side of the indoor unit.

　　 4. Remove the firm pipes and splints on the back of the evaporator, and remove the positioning screws of the indoor evaporator.

　　5. Slightly lift the pipe 20 from the back of the indoor unit with the left hand to move the evaporator forward. After pulling out the evaporator 5cm with your right hand, twist the evaporator 90 degrees with both hands and pull it out along the pipe. Pay attention to the operation with both hands and do not knock the fins down. After removing the evaporator, place it in a flat and clean place, and wipe off the oil spill with a dry cloth. The leaking point is welded with silver welding, after suppressing and introspecting to be sure that it will not leak, install the evaporator on the plastic frame of the indoor unit in the reverse order of assembly.

　　 Refrigerant positive and negative pressure sampling and density measurement

　　 (1) Positive pressure sampling

　　Most lithium bromide absorption computer room air-conditioning units (cold and hot water units) are equipped with solution pumps with higher pressure. Dilute solutions can be sampled under positive pressure conditions. The equipment and connections required for positive pressure sampling.

　　 (2) Negative pressure sampling

The internal pressure of the lithium bromide absorption computer room air-conditioning refrigeration unit (cold and hot water unit) is lower than the atmospheric pressure. When the refrigerant is sampled, the outlet pressure is still lower than the atmospheric pressure due to the lower pressure of the refrigerant pump. Sampling under conditions, with the help of the vacuum drawn by the vacuum pump, the refrigerant water is drawn out, and the pressure of the concentrated solution is also lower than the atmospheric pressure. If sampling is required, it is also necessary to sample under negative pressure. Some lithium bromide absorption units (cold and hot water units) are equipped with solution pumps with lower pressure, and dilute solutions also require negative pressure sampling. Negative pressure sampling equipment and its connections, during the operation, management and maintenance of the unit, the refrigerant water or concentrated solution sampled by dry is less. If it is inconvenient to use a jar, a sampler can be used instead of the jar.

　　(3) Density measurement

The density of the lithium bromide solution is measured to determine the concentration of the solution. The three parameters of concentration, temperature and density are directly related. The density and temperature can be determined to determine the concentration of the solution. The lithium bromide solution should be measured as soon as possible after being poured into the measuring tank. At the same time, the thermometer and density meter must be inserted into the measuring barrel at the same time and read at the same time.

　　 (4) Computer room air conditioning

After measuring the temperature and density, for example, if the measured temperature is 30℃ and the density is 1560kg/m3, find 30℃ as the vertical line, and find 1560kg/m3 as the horizontal line on the vertical coordinate. At the intersection point, the mass concentration (ie, mass fraction) of the lithium bromide solution is 52%.

　　 Several leakage points of refrigerant and repair methods:

　　 (1) Low pressure bypass valve core refrigerant leakage

　　 The refrigeration system of split air conditioner makes up the refrigerant (commonly known as "fluorine addition"), which must be refilled from the low pressure bypass. Use the gas filling pipe with thimble to open the low pressure gas filling valve stem, and connect the r22 refrigerant gas of the refrigerant cylinder to the air conditioner refrigerant gas, and the filling can be ended.

　　The reason for the leakage of the valve core is: the ejector needle of the air filling pipe is too long, and the ejector needle of the bypass valve cannot be rebounded after being pushed out, so that the valve core cannot be reset. The way to eliminate it is to insert the key of the public air conditioner into the refueling valve core and give the valve core a force to make the valve core spring pop out, which can eliminate the valve core air leakage.

　　 (2) Refrigerant leaks from dented pipeline

　　Four deflated pipes and leaks mostly appeared after home renovation. Some decoration workers don't understand that there is refrigerant in the refrigeration pipeline; they bend at will, because there is an insulation jacket outside the pipeline, it is not easy to be invented after bending. After the pipeline collapsed, the refrigerant was leaked, and the system was turned on again to add fluoride, and the refrigeration system showed symptoms of two shutoffs.

　　 Example: A split type air conditioner is not cooling. Use a pressure gauge to test the pressure. The pressure gauge shows negative pressure. After the gas is added to 0.45MPa, the sound of the compressor increases and the indoor unit does not blow out cold air. Remove the casing of the indoor unit, touch the evaporator by hand, it is not cool, peel off the indoor unit pipeline insulation sleeve, and find the low-pressure liquid pipe concave. Use a cutter to remove the concavity and cut-off point, adopt the method of butt joint of outer sleeve, after soldering with silver welding, re-press, check for leaks, drain, add fluorine, and turn on the machine with remote control. However, the air conditioner inherited the above symptoms, indicating that there are two other closures in the pipeline. Inherited the peeling of the outdoor pipeline insulation jacket, and invented the outdoor pipeline low pressure gas pipe was also dented. After the outdoor pipeline is trimmed and welded, turn it on with the remote control, and the air conditioner will be cold.

　　（3）The refrigerant leakage of the four-way reversing valve

　　 There is more leakage at the angles of the three copper pipes on the four-way valve of the heating and cooling type air conditioner. If there are oil stains at the angles, it indicates that there are leaks. The patching method is: first wipe off the oil stains at the corners with a towel, and use the washing spirit to check for leaks, mark the leaks with steel needles, then release the refrigerant, and wrap the four-way reversing valve with a wet towel cool down. When welding, according to your own flame control skills, aim at the leakage point, when the angle reaches the welding temperature, quickly point the silver electrode welding. Manipulate tricks quickly, compete for a victory in welding, and test pressure without fail.

　　 When beginners encounter the leakage of the included angle of the four-way reversing valve, it is best to use the glue method to make up the leakage. Due to the close angle between the nylon spool slider and the leakage point, and the overhead welding is difficult, improper operation will cause the spool to bake and deform. Once the four-way valve slide block blows air, the air conditioner does not control the heat and cold, and the original minor leakage becomes a major failure that cannot be replaced by the four-way valve. This has caused time and economic losses to users. The four-way valve angle gluing method is the same as the compressor gluing method. After pressure testing, leak detection, evacuation, and fluorine addition, the angle leakage of the reversing valve of the air conditioner can be eliminated and the refrigeration can be restored.

　　 (4) Refrigerant leakage of compressor terminal

　　 Compressor terminal refrigerant leakage, which accounts for more than 2% of the leakage fault. Remove the overcurrent and overheat protector cover. If you see oil traces around the compressor terminal, indicate a leak.

　　The way to eliminate is: first unplug the power plug of the air conditioner, and write a note "Someone repaired the air conditioner on the roof, plug in the power supply" and hang it on the socket. In order to prevent training staff from patching outdoor compact machines on the top floor; indoor staff plugged in the power source by mistake, causing personal electric shock and disorder. Then use the F22 meter to test the pressure of the system at the low pressure gas refueling bypass valve.

If the pressure in the system is zero at this time, you can first charge the system with a refrigerant gas at a pressure of 0.3 MPa to avoid no pressure in the system. When the system is leak-tested, the washing machine enters the compressed oil through the leak point to form a contraction. The machine's axle is chaotic.