Abstract: A method is provided for determining a state of a distillation column having multiple column stages for separating a feed fluid stream into individual fluid components. The state is determined by means of a model in a manner dependent on pressure differences prevailing between adjacent column stages. In the model, both gaseous and liquid flows between adjacent column stages are brought about by the pressure differences prevailing between adjacent column stages. A substance quantity flow characterizing gaseous flow between two column stages is given by {dot over (N)}V·RV=CV·?pV. A substance quantity flow characterizing liquid flow between two column stages is given by {dot over (N)}L·RL=CL·?pL. ?pV,L is a total pressure difference between two adjacent column stages. RV,L is a coefficient of resistance between two adjacent column stages and CV,L is a conductance value of flow between two adjacent column stages.

Abstract: The invention relates to a method for determining the state of a heat exchanger device (10) that comprises means for transferring heat with the aid of at least one process stream. A thermohydraulic simulation of the at least one process stream through at least one passage (14) in the heat exchanger device (10) is carried out in order to determine temperature and/or heat transfer coefficient profiles of the means for transferring heat.

Abstract: High-strength, cold-formable steel and a flat steel product produced from such a steel, in which an optimal combination of weldability and a low tendency towards delayed cracking is ensured along with good strength and hot and cold deformability. In order to achieve this, a steel according to the invention contains (in % by weight) C: 0.1-1.0%, Mn: 10-25%, Si: up to 0.5%, Al: 0.3-2%, Cr: 1.5-3.5%, S: <0.03%, P: <0.08%, N: <0.1%, Mo: <2%, B: <0.01%, Ni: <8%, Cu: <5%, Ca: up to 0.015%, at least one element from the group “V, Nb” with the following proviso: Nb: 0.01-0.5%, V: 0.01-0.5% and optionally Ti: 0.01-0.5% and iron and unavoidable, production-related impurities as the remainder.