Necessity of cleaning heat exchanger and determination of cleaning time
The necessity of heat exchanger cleaning
The heat and cold load of the building is carried by the air supply of the air conditioning system. The heat exchanger plays an important role in the air conditioning system. The heat transfer efficiency of heat exchanger directly affects the indoor temperature. Just after the installation and cleaning of the air filter on the air flow resistance is small, the filtration efficiency of filter dust is low, at this time, a large number of small dust particles will reach passes through the filter and the surface of the heat exchanger, and then gathered on the surface of the heat exchanger, the formation of dirt. Due to fouling thermal resistance is far greater than the heat exchanger wall thermal resistance, thereby reducing the heat exchanger capacity, make indoor not need heat (winter), cold (summer), the indoor design temperature will shift, influence the effect of air conditioning, the formation of cold loss of heat, and increased operating costs air conditioning system. On the other hand, the accumulation of dust on the surface of the heat exchanger will breed and multiply bacteria. After "SARS" and "bird flu", people pay more attention to the problem of air pollution [1]. Therefore, the heat exchanger should be cleaned after a certain period of time.
The inner side of the heat exchanger is an air conditioning water (i.e., a heating or cooling medium), and the outer side of the heat exchanger is heated or cooled. The heat exchanger and the air conditioning water system closely connected together, to prevent the heating or cooling medium leakage, it is difficult to remove the heat exchanger for cleaning, can only be carried out on-site cleaning, namely, heat exchanger cleaning, air conditioning systems must stop the normal business impact of commercial buildings. Therefore, the heat exchanger can not be cleaned regularly.
Determination of heat exchanger cleaning time
From the above analysis, we can see that the air conditioning system in the process of operation, the heat exchanger can not be cleaned, can not be cleaned, which is bound to have an optimal cleaning time. Air conditioning has been looking for the best cleaning cycle air conditioning heat exchanger, but because there are many factors affecting the system instability encountered in operation, such as seasonal changes, changes in the weather, air quality, the number and the size of the rain rainfall and the length of time, the result is always unsatisfactory, it is difficult to give a accurate cleaning cycle.
The main factors affecting the heat transfer is the accumulation of surface dust, dust accumulation and system operation time length, but the impact of outdoor air quality and filter effect more, these factors are reflected in the number of dirt on the surface of the heat exchanger, the results are reflected in changes airflow volume and air temperature.
