Frequently Asked Problems of Clean Air Conditioning System and Solutions:

Clean air conditioning system is an indispensable part of pharmaceutical clean engineering. The quality of its running state is related to whether the clean environment can meet the standard, and directly affects the quality of products. In view of the six common problems in the operation of clean air conditioning system, the author combined with the actual situation and his own work experience, one by one made an analysis and discussion, and put forward the corresponding countermeasures, which can be described as "the remedy to the case". It is hoped that this article can bring benefits to the engineering and technical personnel of pharmaceutical enterprises.

Question 1: Leakage countermeasures of the combined air conditioning system: prevention of frost heaving. Detailed replays: there is a large amount of water leakage in the combined air conditioners used by most companies in northern China in winter, which seriously affects the normal production. A fine drying package workshop in last winter suddenly a large number of water leakage, technical personnel to find the reason, eliminate the heater water leakage, humidifier water leakage and other reasons, found that the table cooler water leakage. What's the reason? Stop running in chiller, system has carried on the net after processing, we jointly with the design, manufacture, management personnel many on-site analysis, found that due to the table after cooler frost heave, cause water leakage, while the net system, but some exist blind area, can't put a net, cause a lot of cold air into the winter, the table cooler tube of frost heave. After investigation, most of the manufacturers of combination air conditioners have blind areas, can not be put clean.

The solution to this situation is: when ordering, the equipment manufacturer is required to increase the low point and put the net; The fresh air is treated and the preheating section of fresh air is added to ensure that the temperature after fresh air treatment in winter reaches above 5℃. Electric heating was chosen because steam heaters also have frost heave problems.

Question 2: Short service life of medium and effect filter countermeasures: increase the average flow section details playback: some combined air conditioners have short service cycle of medium and effect filter, and the filtering effect of medium and effect filter is not ideal. The frequent replacement of medium and effect filter not only leads to high daily cost but also reduces the service life of high efficiency filter. After careful comparison of the study showed that some companies because of the air conditioning room area is lesser, designers for structure is compact, the effect of filter directly connected with the fan paragraphs, resulting in the treated air to spread, make the fan outlet in effectively filter the uneven air distribution in the cross section of the filter speed, not only affects the effect of the air conditioning air handling unit, and shorten the service life of the filter. The solution to this problem is to add the average flow section in the fan section and the medium effect filter section.

Question 3: differential pressure and air volume can not meet the requirements countermeasures: positive detection of partial adjustment details carefully playback: once, when a certain preparation workshop found each room pressure differential is chaos, so the workshop air conditioning system of operating staff on technical interlayer debug some back to the wind valve, although the differential pressure and air volume of the room later met the design and use requirements, but several other room instead of air volume and pressure difference has changed, it is difficult to meet the application requirements, the consequences of doing so makes the air conditioning system more chaos. The reason is that the local adjustment of individual tuyere to meet the requirements of air volume and pressure difference will affect the air volume distribution of the whole system and make the air volume distribution of the whole air conditioning system chaotic. Air conditioning system has passed after the completion of measurement and adjustment, the adjustment of air volume generally adjusted by the proportional control method, the valve is in a fixed opening, the entire air conditioning system of air supply outlet air distribution ratio is basically remain unchanged, if separate adjust one or some of the valve, the air distribution of each tuyere will disorderly change, make the air flow and distribution air conditioning system more confusion.

Therefore, it is suggested that the air conditioning user units should find experienced personnel to test and debug after the completion of the project acceptance after construction, so that the system can meet the requirements of design and use, because the test and adjustment of the air conditioning system is an important part of the whole air conditioning project; The air conditioning system that has been built and put into use should not be easily adjusted locally. Of course, if the process changes or improper maintenance management, there may also be system maladjustment or failure, through measurement and adjustment can find out the cause of the fault, and then improve the operating conditions, so that the system runs normally.

Question 4: Indoor air supply outlet condensation countermeasures: to avoid dew point temperature air supply details playback: in a fine drying package workshop, the surface cooling section is set in the negative pressure section of the fan, and everything is normal after system debugging. However, once the chiller is started, a large number of water drops are gathered near the indoor air supply outlet, which makes the indoor relative humidity very high, and the product has a strong moisture absorption, which seriously affects the quality of the product.

In view of this phenomenon, the design, construction, equipment, engineering management and user units for many times on site observation, discussion and research, think that cause this phenomenon may have the following reasons: after the surface cooler is not set water baffles; The air supply temperature is low and reaches the dew point temperature. After the cold air enters the room, the indoor air reaches the dew point temperature and condensation occurs.

For these two reasons, technicians first added a water retaining board in the cold section of the surface, and added a secondary electric heater on the air supply pipe. Although the situation has improved somewhat since then, it has not been resolved. After observation, there is still the phenomenon of air passing through the surface cooler with water, and the water cooled down by the condenser can not be eliminated. Compared with other air conditioning units, it is found that the base of this combined air conditioner is lower and the condensation bend is shorter. In theory, in order to easily eliminate the condensation pipe in the chassis of the condenser, the water seal of the surface cooler should meet the following requirements: H1 >1.2P, H2 BBB>6P, where P is the negative pressure of the fan of the surface cooler (millimeter water column).

In practice, many combined air conditioners are installed due to a low base, and the production of condensate bend can not be manufactured according to the requirements of the drawings, resulting in the condensate water in the bottom plate of the table cooler is not easy to be eliminated. With the continuous accumulation and increase of water, it will be taken to the pipeline and room by air. This problem should be taken into account during installation, to allow sufficient installation space for the condensate bend or to consider setting the surface cooling section at the positive pressure section of the fan during design.

Here, it is worth mentioning, manufacturability air conditioning especially more strict with relative humidity place should avoid air dew point temperature, dew point temperature of air supply will lead to the low supply air temperature and relative humidity is very high, some designers in air before setting the second heater to solve the problem, but it caused the waste of energy, so the application of the secondary return air way for improvement of the supply air temperature, avoid air dew point temperature at the same time saves energy.

Question 5: the expansion box frozen water overflow countermeasure: increase the volume of the position of the rise Details playback: the air conditioning water system expands and contracts with the change of temperature, the expansion tank is to store the expanded water, and at the same time to supplement the water system volume contraction of the water, another function is the constant pressure of the pump.

In some preparation workshops, a large amount of water overflowed in the expansion tank during the test run, so the expansion tube had to be closed. One of the reasons is that the volume of the expansion tank is small; The second reason is that the location of the expansion tank is not set properly. The solution is: the volume of the expansion tank should follow the formula: V=α×△ Tmax × VC (V is the volume of the expansion tank, α is the unit expansion coefficient of water, △ Tmax is the fluctuation value of the water temperature in the system, VC is the volume of water in the system), when the calculated V value is less than 2% of the value of VC, 2% of the value of VC is selected; The installation position of the expansion tank should also be at the point of the system, and should be 0.5 meters higher than the point of the system.

Question 6: inlet air conditioning dripping countermeasures: increase exhaust pipe grade details playback: local exhaust air exhaust system is mainly for centrifuge task, when the centrifuge is working to produce a large amount of water vapor, the water vapor will mixed cooled in the air condenses into lots of small water droplets, and in the duct has a slight slope during the construction of slope to the interior, once stop, are gathered in the water drops on air duct in the along the duct flow back to the room. Therefore, the technical personnel believe that the exhaust pipe in the northern region should be insulated and the exhaust pipe should have a certain slope slope to the outdoor.