Probachay Alexey

Abstract of thesis

          One of indexes of manoeuvrability of power units is duration of the starting modes of tubin after the stops of different duration.

          During starting and the stop of block is visible uneven distributing of the temperature fields in the metal of turbine, and possibly and geometrical changes in the structure of aggregate. the uneven change of axial gaps creates an emergency situation and causes the necessity of stop of block. The uneven warming up is caused by the change of height indexes of cylinder and violation of centration of rotors, that results in a disbalance and death of all turbine.

          For timing output of turbine on the nominal loading conformities to law of change of temperature are in-process used in time. It is information from the decision of tasks of rational management the non-stationary thermal state of limiting knots, arising up in them thermal tensions during all transient. Such condition allows to get the value of minimum duration of the stage of warming-ladening.
          Variants are considered, when the coefficients of concentration of tensions were evened: for the areas of rotors 3 and 5; for the areas of flancev 1,5 and 2. Analiz shows that determining duration of ladening of turbine there is an area of rotor of middle pressure in the area of entrance of steam. If on the areas of RVD and RSD (in the area of entrance of steam) coefficients of concentration of tensions will not be more than 3, duration of ladening of turbine after stops to 48 hours will determine RSD, and at stops over 48 hours the area of FNK CVD will serve as a limiting knot in the area of parovpuska.f in connections of horizontal sockets CVP and CSD the coefficients of concentration of tensions will not exceed 1,5, a limiting knot for all variants will be RSD in the area of parovpuska.

          A requirement specification on planning of the modernized turbines of type of K-300-240 rations duration of starting of turbine from the different thermal states (from a start to the set of the nominal loading):
– cold state – 5 hours;
– ungetting cold state (outage 36 … 48 hours) – 2,5 hour;
– ungetting cold state (outage 15 … 36 hours) – 1,5 hour;
– hot state (outage 6 … 10 hours) – 1 hour.
          Comparing the rationed information to the real results draw conclusion, for providing of requirements it is necessary on manoeuvre descriptions of turbine, that coefficients of concentration of tensions in connections of outward corps CVP and CSD did not exceed 1,5, and in RSD and RVD did not exceed 3. If it will be impossible to provide such coefficients of concentration of tensions, then it is necessary it will be to carry out measures on strengthening of thermal defence of the union couplings of pipelines and supporting paws of cylinders.
          In particular, to put Electroheater (as spirals of variable resistance) on the union couplings of external corps, powers of which sneak up on the size of thermal streams, taken through the union couplings in initial moments of process. After the progrva electro-heating becomes disconnected. Electro-heating can be put and on paws, if it is impossible to inflict an isolation, but it is needed to set CRT defence for the protection of corps of the supporting bearings from an overheat.

    Literature:

1. Sheptun N.,Control of temperatures during work of turbine in the normal and transitional modes./ Scientifically research work of student.

2. Truhin А., Stationary steam-turbines.-2 edit.-М.:Energoatomizdat,1990.-640с.

3. Shtromberg Y., Ponasechnik S.А., Kopsof А.Y. Povrezhdaemost' of teploenergeticheskikh blocks by power 300 MVt // Electric stations. 2000. № 3. С. 16—18.

4. Automation of thermal processes on power-stations./V.М. Maynulov P.N./«Energiyz». М – 114, 1970.