A method for operating an air separation plant having a distillation column system, a heat exchanger, and an adsorber, wherein, in a first time period, a first operating mode is carried out and, in a second time period following the first time period, a second operating mode is carried out. In a third time period between the second time period and the first time period, a third operating mode is carried out, in which third operating mode compressed air is at least partially freed of water and carbon dioxide in the adsorber and at least part of said compressed air is cooled in the heat exchanger, an air product is removed from the distillation column system and at least part of said air product is heated in the heat exchanger.

The present invention relates to a method and to a graphical user interface for managing a process engineering facility comprising at least one heat exchanger, wherein each of these heat exchangers is designed as a plate heat exchanger and each comprises a plurality of heat exchanger blocks, the method comprising: receiving sensor values from sensors which are arranged on or in the at least one heat exchanger; determining parameters which characterize an operation of the at least one heat exchanger on the basis of the received sensor values, wherein a temperature difference between heat exchanger blocks of the at least one heat exchanger is determined as a parameter; processing the sensor values and/or the parameters for a graphical display of a state of the at least one heat exchanger.