Abstract: A method of determining heat losses due to incomplete fuel combustion consists in that periodic sampling of fuel combustion products is carried out. The sample is separated into two parts, one of which includes a gaseous phase, and the other, a solid and a gaseous phases. Oxygen concentration in each part is assessed, after which both parts are heated and burnt up to determine oxygen concentration after burning. Oxygen losses in the gaseous phase and in the mixture of the solid and the gaseous phases are determined, and heat losses due to chemical and total underburning of fuel are defined as the ratio between oxygen losses. Then heat losses due to mechanical underburning of fuel are estimated as the difference of heat losses due to total chemical and mechanical underburning, and chemical underburning of fuel.

Abstract: A method of short-circuit protection of an electrical three-phase machine, realized in a short-circuit protection device for a three-phase electrical machine, provides that phase currents are formed in phases of the stator winding of a three-phase electrical machine and, concurrently, a magnetic flux is produced by the end loops of coil groups of each phase in the stator winding, and a reverse current is separated from phase currents by a reverse current discriminating unit. Afterwards, current measuring and comparing units simultaneously measure the reverse current and the total electromotive force, produced by the magnetic flux in conditions excluding short-circuits in the stator winding and added up by a means for summing and converting magnetic fluxes into the electromotive force. In case the measured magnitude of the current and the value of the electromotive force exceed the maximum, three-phase electrical machine disconnection signal shapers produced respective signals which cut out the machine.