In normal operation, the greatest impact on the operating cycle is the quality of temperature difference control at the cold end of the switching heat exchanger. Poor temperature control can lead to poor self-cleaning effect of the switching heat exchanger, as carbon dioxide accumulates in the heat exchanger and increases its resistance; On the other hand, it will cause a small amount of carbon dioxide to enter the tower. Due to the impact of air flow, the actual content of carbon dioxide in the air at the cold end of the cooler and the switching heat exchanger will exceed the saturation content, which will also affect the operation cycle. Especially when the cold section of the switching heat exchanger is too short, the precipitation zone of carbon dioxide is shortened, which is more likely to bring some carbon dioxide into the tower, causing an increase in resistance of the distillation tower, weakened heat exchange of the main cooling system, blocked subcoolers, increased pressure in the lower tower, and decreased air and oxygen production into the tower.
Switching heat exchangers with water will also shorten the operating cycle. Usually caused by improper operation of the nitrogen water precooler. However, slight water ingress is often due to neglecting the blowing of the water separator and the discharge of condensed water in the air main of the switching heat exchanger.
The state of the air processed by the air separation equipment is also an important factor affecting the operating cycle. Due to an increase in air volume or inlet air temperature, the burden of removing moisture from the cold storage or switching heat exchanger will be increased, resulting in an increase in heat exchange temperature difference. At the cold end, it manifests as poor self-cleaning and accelerated resistance increase. Therefore, during high load production, the operating cycle is generally shortened, while at low load, the operating cycle can generally be extended.
DEAR Air Separation's gas investment business has multiple operational projects across the country. According to relevant statistics, "the growth rate of Industrial gas is 1.25~1.5 times of GDP growth." This data is based on the study of Industrial gas in the United States for 10 years and Industrial gas in China for 50 years. Data shows that China's Industrial gas has entered a rapid development stage after 2010. The annual growth rate of Industrial gas in China was 12% in 2012 and 10% in 2017. Experts predict that the annual output value of Industrial gas in China will reach 120 billion yuan in 2020.
