The cooling water in the cryogenic air separation unit requires clean water quality, moderate hardness, suitable temperature, sufficient flow rate, and stable pressure.
Cooling water must be kept clean to avoid suspended solids, dissolved salts, hydrocarbon gases, and other pollutants. The hardness of cooling water should be controlled within a certain range. Excessive hardness can easily form scale inside the equipment, affecting heat transfer efficiency. The pH value of cooling water should be maintained within an appropriate range to avoid corrosion of equipment caused by excessive acidity or alkalinity. The dissolved oxygen content in cooling water should be kept as low as possible to reduce oxidation and corrosion of equipment. The supply temperature of cooling water should be determined according to the specific requirements of the air separation unit. Generally speaking, the water supply temperature should be lower than the temperature of the cooled medium to ensure effective heat exchange. After heat exchange, the return water temperature of the cooling water will increase. The temperature of the return water reflects the efficiency of heat exchange. The flow rate of cooling water should meet the thermal load requirements of the air separation unit to ensure sufficient cooling of the equipment. A low flow rate can lead to insufficient cooling, while a high flow rate can result in energy waste. The supply pressure and return pressure of cooling water should be determined based on the specific requirements of the air separation unit and the resistance loss of the pipeline system. The water supply pressure should be sufficient to overcome pipeline resistance and equipment resistance, ensuring that the cooling water can be smoothly delivered to various cooling parts.
Therefore, the cooling water in the air separation unit plays a crucial role in maintaining the normal operation of the equipment and ensuring product purity.
