The main heat exchanger is the key equipment to ensure the performance of small air separation units, affecting its performance mainly in the following areas.
1, expander efficiency: air compressor exhaust volume is the process is given, the expansion air volume increases, the amount of positive flow air is reduced, so that the main heat exchanger cold end of the thermal load is reduced, the cold volume moved up to the hot end, the hot end of the cold excess, it will cause the main heat exchanger hot end temperature difference increases.
2, molecular sieve adsorber: when the molecular sieve adsorber is not filled with enough, the bed is not flat, molecular sieve regeneration is not complete, molecular sieve adsorption performance is poor, structural defects and other reasons caused by air short circuit, due to manufacturing problems caused by molecular sieve leakage and other reasons, will affect the air moisture, CO2 adsorption, resulting in the main heat exchanger hot end temperature difference and resistance rise.
3, run cold loss: small air separation unit distillation tower system cold loss, part of the main heat exchanger loss of reheat deficiency, another part of the small air separation unit outside environment run cold loss. The size of the reheat deficiency loss is determined by the temperature difference between the hot end of the main heat exchanger, set by the process; while the run cooling loss is estimated based on experience, is a process parameter. The difference between the set value of the run-off loss and the actual value in operation also has a direct impact on the temperature difference between the hot end of the main heat exchanger.
DEAR Air Separation has learned through long experience that a correct analysis of the external factors affecting the performance of the main heat exchanger is a shortcut to solving problems with small air separation units, large air separation units and liquid air separation plants. Therefore, the main heat exchanger is the key equipment to ensure the performance of small air separation units, large air separation units and liquid air separation plants.
