Publish Time: 2022-08-08 Origin: Site
With the gradual increase in the age of the aircraft, and the damage to the air-conditioning system caused by catkins and air pollution in certain seasons, the performance of the air-conditioning system will be attenuated or even deteriorated when the new aircraft is put into use for about two years. This will also increase the airline's additional maintenance costs and parking time. Especially in the hot summer, it will seriously affect the comfort of the cockpit and cabin. Therefore, it becomes more and more important to evaluate their service environment and system state from the system, and return to the initial service state as soon as possible.
The performance degradation of the air-conditioning system is usually manifested as: the actual temperature of the cockpit or the actual temperature of the cabin has a large deviation from the preset temperature when the temperature is high in summer, and the actual temperature is higher than the preset temperature. The performance degradation of the air-conditioning system is more obvious in summer, and is often less noticeable in other seasons. The air-conditioning system has many components, and there is no fault information when most faults occur, so it is difficult to determine the source of the fault. Even if the source of the fault is finally judged correctly, due to the large fleet size, many air-conditioning components need to be replaced and the preparation period of aviation materials is long. Once the fault is reflected in a centralized manner, it will not only affect the quality of cabin service, but also put pressure on the maintenance economy.
The reasons for the performance degradation of the air conditioning system can be said to be multi-faceted, involving the atmospheric environment, component manufacturing process, regional environment, component reliability, maintenance quality, etc. At present, the company's MTOP (Continuous Airworthiness Maintenance Program Implementation Plan) replaces and cleans the air-conditioning system heat exchanger, which shortens the replacement cycle. However, often after the replacement is completed, secondary replacement work will occur due to seasonal catkin pollution; in addition, due to the manufacturer's design and manufacturing reasons, the reliability of the components is also low, such as the failure of the condenser is mostly concentrated in the shell rupture. ; The construction ability of the maintenance personnel is not uneven, which also leads to the phenomenon that the assembly process of the system components is not as good as that of the original factory after many times of disassembly and assembly, resulting in leakage of pipeline joints.
1. Regularly assess the overall condition of the aircraft air conditioning system
(1) APMS system monitoring. Use APMS to monitor the trend of several main working parameters of the air-conditioning system. Such as PACK outlet temperature, air flow, compressor outlet temperature and other parameters. The trend changes of these parameters can often detect the hidden diseases of the system in advance.
(2) Field maintenance should be discovered as soon as possible. The work item of opening the belly cover is often encountered during routine and non-routine inspections in the field. At this time, the inspection of air-conditioning system components and pipelines is increased, and some obvious pipeline leakage phenomena can be detected and dealt with in advance to prevent problems before they occur.
(3) Maintenance plan documents. Strictly implement the regular inspection and testing of the air conditioning system in MTOP. For some parts that need to be replaced and cleaned regularly, make appropriate adjustments within the time limit specified by CAMP, and try to arrange the completion before the arrival of the high temperature in summer. Premature completion will often cause the parts to be polluted again before the high temperature arrives.
The multi-system, multi-department and multi-channel joint control has achieved the monitoring of the fleet air-conditioning system in place from the multi-process management and control level. On this basis, combined with the specific daily production situation, arrange non-routine and gradual completion of the system recovery work, maintain good system performance, and avoid the overall performance decline of fleet air conditioners.
2. Research on the countermeasures after the performance of the air-conditioning system is attenuated
When the performance of the air conditioning system of multiple aircraft in the fleet deteriorates at the same time, the existing resources and data should be used reasonably to make a comprehensive analysis of the entire fleet. Return to work.
(1) First complete the performance ranking of the fleet air conditioning system
By collecting APMS system data for secondary analysis, combined with unit reflection, ground observation and other information after comprehensive analysis, the performance of the fleet air conditioning system is ranked. In the follow-up troubleshooting work, reasonable planned troubleshooting can be carried out according to the "air conditioning system performance ranking table" combined with the specific flight plan, which can quickly control the deterioration of the system status while rationally utilizing maintenance resources.
Air conditioning components performance ranking table:
B-68AA, the crew report obviously needs to be dealt with as soon as possible.
For B-69BB, the left and right component heat exchangers need to be replaced.
For the B-18CC, the performance of the air conditioning components gradually deteriorated.
B-67DD, Component 1 performance has a tendency to deteriorate.
For B-69EE, ACM performance is degraded, and a visual inspection of the hose for air leaks should be completed first.
B-67FF, observational use.
B-68GG, good performance.
B-69HH, good performance.
B-99JJ, good performance.
(2) Second, formulate a recovery plan for the air conditioning system
According to the performance ranking table of air-conditioning components, the "air-conditioning system performance recovery plan" of the fleet is formulated. The main contents include reference to the ranking of the "air-conditioning component performance ranking table", preliminary treatment plan, completed status, follow-up performance analysis, and follow-up treatment plan.
First, make a preliminary treatment plan and record the completion of the preliminary treatment. After that, continue to monitor, and then do follow-up performance analysis according to the monitoring situation. After analysis, complete the formulation of follow-up processing plans as appropriate. After two rounds of orderly troubleshooting, most of the problems were resolved and the deterioration of the entire fleet was brought under control.
"Performance Ranking" and "Performance Recovery Plan" are the core of countermeasures after performance decay. After a systematic summary and orderly troubleshooting, it can be said that the deterioration of the overall performance of the fleet can be quickly controlled and gradually restored to a normal state.
Air conditioning system failures can be said to be frequent and common on airline routes. The system performance degradation is usually difficult to detect, and often occurs after the combination of extreme weather and system deterioration. If left unchecked, it will not only increase maintenance costs, but also take up a lot of maintenance resources, and even the leakage of some pipelines will cause serious consequences such as depressurization of the cabin and return to flight.