RU1783242C - Flue - Google Patents

Description

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(21) 4863694/33 (22) 04.09.90 (46) 12/23/92. Bull. Number 47

(71) Ivanovo Energy Institute named after V.I. Lenin

(72) Yu.V. Salov, B.L. Shelygin, V.V. Varnashov, and A.S. Osyka

(56) Copyright certificate of the USSR No. 802712, cl. P 23 J 13/06. 1979. (54) SMOKE PIPE

(57) Use: eliminates the growth of temperature stresses and corrosion. SUMMARY OF THE INVENTION: A chimney contains a carrier shell, a gas outlet trunk, cold gas ducts, an insert and a perforated barrel mounted coaxially with it. High-temperature gases through the confuser insert enter the perforated barrel and part of the low-temperature gases is sucked in. The distance between the holes along the height of the barrel is increased by 1 sludge.

The invention relates to the field of energy and can be used in the construction of chimneys for the removal of flue gases from power boilers and gas turbine plants.

Known chimney with separate, independent input into the exhaust pipe of the ducts of high temperature and low temperature gases

The closest in its technical essence and the achieved effect is a chimney containing a pressure lining and communicated with the lower part with the ducts of hot and cold gases. In this case, the pipe is axially connected with the gas ducts of hot gases through an additionally installed confuser insert. Hot products of combustion with a temperature of 230-2 ° C (og peak boilers) enter the chimney through the confuser insert along the axis of the barrel a. .Cold gases with a temperature of 140-160 ° C (from energy boilers), exit from the flues, wash the confuser insert from the outside and rise along the inner surface

lining, squeeze hot gases from the latter to the axis of the barrel, protecting it from contact with hot gases.

The disadvantage of this chimney is the impossibility of its reliable operation when exhausting gases leaving their gas turbine unit through a confuser insert. At a high flow rate of high temperature gases leaving a gas turbine unit (450-550 ° C), the effect of squeezing them from the lining is by a ring stream of low temperature gases worsens. In this case, immediately at the outlet of their confuser, the flows of hot and cold gases are mixed, and the upstream lining of the gas outlet of the borehole begins to be washed by the high-temperature nofoKoM. destroying the exhaust pipe (cracking, leaks), which reduces the durability of the chimney. Another disadvantage is the occurrence during the start-up and shutdown of the gas turbine installation in the gas outlet trunk of additional temperature stresses, which exacerbate the destruction of the chimney elements during

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abrupt heating and cooling of the exhaust pipe

The purpose of the invention is to increase reliability.

This goal is achieved by the fact that in the chimney communicated by the lower part with the hot and cold gas ducts, the pipe being communicated with the hot gas duct through the confuser insert installed along the axis of its lower part, a barrel for removal is installed coaxially with the pipe high temperature gases perforated by rows of holes. Printed along the height of the barrel, the distance between the rows of holes is continuously increasing.

A perforated barrel mounted on the confuser insert eliminates the contact of high temperature gases with the surface of the exhaust pipe and prevents the mixing of hot and cold gases in the near-boundary boundary layer of the stream washing the inside of the pipe. This eliminates the increase in temperature of the exhaust pipe and prevents its destruction, which increases the durability of the pipe. Perforation of the barrel mounted on the confuser insert, with a series of holes, allows suction through them into the interior of the barrel for part of the cold gases moving in the annular space along the inner surface of the exhaust barrel. During the operation of a gas turbine installation, part of the cold gases that have penetrated through a series of holes moves from bottom to top in the wall boundary layer of the barrel mounted on the confuser insert. Washing off the inner surface of the perforated barrel (in its wall boundary layer) with cold gases eliminates the increase in the temperature of the metal wall and prevents scale formation and gas corrosion of the barrel (burnout). Reducing the distance between the rows of holes in the perforated barrel is intended to improve the flow of cold gases into the lower part of the barrel and to reduce the flow of sucked-in gases into the wall boundary layer, where the temperature is lower than in the lower part of the barrel.

The drawing shows the construction of an enclosed chimney.

The smoke pipe includes a reinforced concrete sheath 1 and a gas outlet barrel 2 located inside it; communicated with the duct 3 for the removal of low-temperature flue gases from power boilers Inside the barrel 2 in its lower part along the axis there is a confuser insert 4,

in communication with a duct 5 for venting high temperature gases from a gas turbine unit. A barrel 6 is installed on the confuser insert 4 coaxially with the barrel 2 for venting high-temperature gases, perforated by rows of holes 7

Danna chimney works as follows.

Low-temperature flue gases (140-160 ° C) from energy boilers through the gas duct 3 enter the annular space between the shafts 2 and b and, moving from bottom to top along their surfaces, are removed to

the atmosphere. High-temperature gases (450-550 ° С) leaving the turbine gas pipe, through the gas duct 5 through the confuser insert 4, enter the barrel 6. Taking into account the flow rates of hot and cold gases, the diameters of the shafts 2 and 6 are chosen so that the velocity of the high-temperature gases inside barrel 6 exceeded the speed of low-temperature gases in the annular space between the trunks 2 and 6. Due to

the resulting difference in the static pressure of the flows of cold and hot gases, part of the low-temperature gases is sucked through a series of holes 7 into the inside of the barrel 6. In this case, this part of the cold gases moves from bottom to top around the entire perimeter of the inner surface of the barrel 6, in its wall boundary layer, excluding thereby increasing the temperature of the metal of the barrel 6 above an acceptable value. Thereby, scale formation and gas corrosion of the barrel 6 are prevented during the removal of high-temperature gases during the operation of the gas turbine unit. The diameter, the number of holes, the number of rows 7 and the unevenness of their placement along the height of the barrel 6 are taken from the condition of effective and uniform washing in the inner wall boundary layer with a portion of the cold gases of the inner surface of the barrel 6 in order to prevent burnout. When the gas turbine stops, the flow of high-temperature gases through the gas duct 5 and the barrel 6 stops and the temperature of the metal of the barrel 6 begins to decrease. Washing the outside of the barrel with 6 low-temperature gases reduces the rate of cooling of the latter, decreasing the temperature (metal stresses, reduces the temperature gradient between the internal and

the outer surfaces of the barrel 6, which eliminates the occurrence of cracks and leaks, increasing the life of the chimney. Upon termination of the shutdown of the gas turbine installation as a result of washing the barrel 6 with low-temperature gases coming from the gas duct 3, the temperature of the wall of the barrel 6 is maintained above the condensation temperature of the aggressive vapors, which eliminates one-hundred-percent corrosion of the barrel 6. Thus, the capital costs of manufacturing and repairing the chimney are reduced.

The use of this invention improves the reliability of the operation of the chimney with the joint removal of exhaust gases from gas turbine plants and. power boilers

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Claims (1)

SUMMARY OF THE INVENTION A smoke pipe communicated at the bottom with cold gas ducts and a hot gas duct through a confuser box installed along the axis of its bottom, characterized in that, in order to increase reliability, it is provided aligned with the confuser insert a barrel for venting high-temperature gases with perforated rows of openings with increasing distance between them in height.