Abstract: A method of determining a leakage in a heat transfer fluid channel of a heat transferring reactor system includes measuring the heat transfer fluid flow rate prevailing in the channel, modelling heat transfer heat transfer fluid flow rate in the channel during operation utilizing process data in a numerical model giving the fluid flow rate of the system under substantially leak-free conditions, comparing the measured fluid flow rate and modelled fluid flow rate to obtain an error measure for heat transfer fluid flow rate included in an error measure set, monitoring the error measure set and a number of occurrences, and determining the presence of a heat transfer fluid channel leakage in case the error measures exceed a pre-defined threshold, or a number of occurrences in the error measure set exceed a predetermined threshold during a predetermined time period.

Abstract: A method of determining a tube leakage in a water-steam circuit of a combustion boiler system. The method includes measuring a main steam flow (QMS,M) prevailing in the water-steam circuit of the system during operation, modelling the main steam flow (QMS,C) in the water-steam circuit during operation by utilizing process data in a numerical model of the system giving the main steam (QMS,C) flow of the system under substantially tube-leak-free conditions, comparing the measured water-steam flow with the modelled water-steam flow to obtain an error measure (DMS) for main steam flow included in an error measure set, monitoring the error measure set and number of occurrences in the error measure set during operation, and determining the presence of a water-steam circuit tube leakage when error measures (?MS) exceed a pre-defined threshold, or a number of occurrences in the error measure set exceed a predetermined threshold during a predetermined time period.

Abstract: A method of preventing blockage of circulating bed material in a circulating fluidized bed reactor includes collecting a continuously flowing bed of solid particles in a gas lock in a return leg of a reactor, measuring gas lock bed pressure values within the bed of the particles, generating a gas lock bed height indication signal on the basis of measured gas lock bed pressure values. A definition stage includes defining and storing to a control system a range of normal gas lock bed height indication signals, formed in normal circulation flow conditions, as a function of the reactor load, and defining and storing to the digital control system a reactor load dependent alarm criterion. The method includes comparing a current gas lock bed height indication signal with the reactor load dependent alarm criterion, and decreasing the reactor load if the current indication signal fulfils the reactor load dependent alarm criterion.

Abstract: An arrangement for feeding ammonia containing fluid into an exhaust gas passage of a combustion plant includes a first fluid line connectable in flow connection with a source of an ammonia containing fluid. A second fluid line is in flow connection with a source of a dilution fluid. A control unit controls multiple valve members of a valve unit, each of the valve members having a first inlet in flow connection with the first fluid line, a second inlet in flow connection with the second fluid line and an outlet in flow connection with an outlet channel connected to the exhaust gas passage. The valve members are connected in parallel so that the outlet of each of the valve members is in flow connection with a common outlet channel.

Abstract: An arrangement for feeding ammonia containing fluid into an exhaust gas passage of a combustion plant includes a first fluid line connectable in flow connection with a source of an ammonia containing fluid. A second fluid line is in flow connection with a source of a dilution fluid. A control unit controls multiple valve members of a valve unit, each of the valve members having a first inlet in flow connection with the first fluid line, a second inlet in flow connection with the second fluid line and an outlet in flow connection with an outlet channel connected to the exhaust gas passage. The valve members are connected in parallel so that the outlet of each of the valve members is in flow connection with a common outlet channel.