Variation characteristics of performance parameters of underground railway environmental control air system with operating years

Adopts the stratified sampling method to select 18 stations in the short-term, middle-term and long-term operations of Shanghai underground railway, carries out the field test of the air conditioning boxes and the return fans of the environmental control air system, and obtains the variation characteristics of performance parameters of underground railway environmental control air system and equipment with operating years. In underground railway operation, the cooling capacity of air conditioning boxes will attenuate by about 18% in the short-term, and the long-term cooling capacity attenuation will be as high as 60%. The performance of supply and return fans of the air conditioning boxes has been maintained at a high level, and there is no obvious linear relationship with the operating years. The average cooling energy efficiency ratio of the air conditioning system is 1.00, 1.63 and 1.18 in the short-term, medium-term and long-term operations respectively, showing the characteristics of higher mid-term and lower short-term and long-term changes.