Method and apparatus for operational monitoring of a condenser with tubes, by measurements at selected tubes

In a condenser including:

• a steam chamber through which steam to be condensed flows, at least one configuration in the steam chamber having a multiplicity of tubes, each of the tubes having inlet and outlet ends for conducting a flow of a coolant fluid through the tubes from the inlet ends to the outlet ends, and the multiplicity of tubes having a plurality of selected tubes,
• an apparatus for operational monitoring of the condenser, comprising:
• a) means disposed at least at one measuring point in the steam chamber for measuring at least one of steam pressure and steam temperature;
• b) inlet temperature sensors each being disposed at the inlet end of a respective one of the selected tubes, outlet temperature sensors each being disposed at the outlet end of a respective one of the selected tubes, and means disposed at each respective selected tube for measuring mass throughput;
• and
• c) a diagnosis device being connected to said means for measuring at least one of steam temperature and steam pressure, to said inlet temperature sensors, to said outlet temperature sensors, and to said means for measuring the mass throughput, for determining an ambient temperature defined as a temperature of the steam immediately flowing around each selected tube from one of the steam temperature and the steam pressure, as well as a previously ascertained form of a distribution of at least one of the pressure and the temperature in the steam chamber;
• and for calculating a heat transfer coefficient from a product of the mass throughput and a logarithm of a quotient of differences between the ambient temperature and the inlet temperature as well as between the ambient temperature and the outlet temperature, for each of the selected tubes;
• and for comparing the heat transfer coefficients of all of the selected tubes with a set-point value, and issuing a warning if at least one of the heat transfer coefficients deviates substantially from the set-point value.