SU1767297A1 - Recuperator - Google Patents

Description

(21) 4817687/06 (22) 04.23.90 (46) 07.10.92. Bul №37

(71) Kiev Institute of Civil Engineering

(72) V.I. Moiseev, S.V. Baranovsk, S.P.Moroz and A.A.Hudenko

(56) 1. USSR Author's Certificate No. 1019179, class, F 23 L 15/04, 1980.

2. USSR author's certificate No. 1267115, cl. F 23 L 15/04, 1985.

(54) RE COOPER ATOP

(57) The invention relates to heat exchangers and can be used to preheat the air in furnaces in mechanical engineering, construction. The purpose of the invention is to increase efficiency by reducing the thermodynamic loss of heat when the air is heated. The cold air enters the inlet of the distribution chamber 1 and as it passes through it flows out through the gas outlets 2, provided with nozzles 3, which are made as long as they decrease from the periphery of the duct to the center. 1 il.

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The invention relates to heat exchangers and can be used to heat the air in the furnaces of the mechanical engineering, construction industry, etc.

A recuperator 1 is known, the disadvantage of which is the low coefficient of heat transfer from the wall to the heated air, caused by the low efficiency of the jet air leakage to the wall due to the absence of nozzles on the outlet openings.

The closest technical solution to the present invention is a recuperator 2 containing a distribution chamber with gas outlets, each of which is provided with a nozzle directed to the heat transfer wall. The nozzles are made of variable length, increasing along the gas flow.

The disadvantage of this heat exchanger is the reduced thermodynamic efficiency caused by the loss of energy of the heated air.

In the known recuperator, the length of the air outlet pipes monotonously decreases from top to bottom, and the distance from the exit edge of the preheat transfer wall nozzle increases accordingly. With this design of the heat exchanger, the maximum air flow rate will be at the lowest branch pipe, the edge of which will be farthest from the heat transfer wall, and the minimum at the top. The value of air flow in this case is determined mainly by the aerodynamic resistance to the air outlet from the nozzle, which in turn is determined by the distance from the exit edge of the nozzle to the wall (see Idelchik I.E., Handbook of Hydraulic Resistances. Moscow: Energy Publishing, 1975).

At the same time, the temperature, the velocity of the gases and, consequently, the heat flux are maximal at the center of the duct and minimal at its walls. If the air maximum reaches the lower part of the heat exchanger, the minimum goes to the upper and some intermediate value to the central, then taking into account the different heat flow from the gases in the lower part, the temperature will be obviously lower than in any other part of the heat exchanger, since the amount of air incoming in the lower part of the maximum, and the heat flow from the gases - is minimal.

Mixing in the annular channel air flows with different temperatures will lead to a drop in the total potential (temperature) of the air flow and reduce the efficiency of heating the air in the recuperator.

The purpose of the invention is to increase efficiency by reducing the thermodynamic loss of heat when the air is heated.

In a heat exchanger containing a distribution chamber with gas outlets with variable length nozzles directed to the heat transfer wall, the goal is achieved by placing the nozzles with increasing length from the center of the duct to its periphery.

This design of the heat exchanger allows the air to be distributed along the height of the heat exchanger in proportion to the heat flow perceived by the heat transfer wall from the side of the gases, i.e. maximum air is supplied to the central

0 part of the heat exchanger, where the temperature of the gases and their speed are maximum. In this case, the air heating temperatures along the entire height of the heat exchanger will be approximately the same and the energy losses of the heated air will be minimal. The effect of the drift of air flow can be eliminated by appropriate selection of the velocity in the annular channel of the heat exchanger compared to the velocity of the air outlet from the nozzle.

0 Thus, the differences in the claimed recuperator are significant.

The drawing shows the proposed heat exchanger, general view.

The recuperator contains a distributor chamber 1 with gas openings 2, each of which is equipped with a nozzle 3 directed to the heat transfer wall. Nozzles 3 are made of variable length, decreasing from the periphery of the duct

0 to the center.

The recuperator operates as follows.

The cold air enters the inlet of the distribution chamber 1 and, as it passes through it, flows through the gas outlets 2, provided with nozzles 3, to the heat transfer wall 4, which is heated by washing with flue gases and radiation of the masonry. After heating, the air passes through the annular gap and is discharged from the heat exchanger.

To reduce the thermodynamic heat loss when the air is heated, this is achieved by distributing the air over

5, the height of the heat exchanger is proportional to the heat flux; the nozzles 3 are of a length that decreases from the periphery of the duct to the center. In this case, the distance of the edge of the nozzle from the heat transfer wall varies from 0.15 to 0.5 equivalent5 17672976

t the diameter of the air outlet holes, equipped with pipes peresti (see I. Edelnik. Guide to hydraulic length, aimed at heat and hydraulic resistance). thinning wall, characterized by that.

The economic effect on one rekupe-that, in order to increase the efficiency of the purator is 200 rubles. 10 thousand m3 uchi-5 to reduce thermodynamic losses

lysed gas. heat when air is heated, nozzles of the size of the invention are placed with increasing length from the center. The recuperator containing the gas duct distributor to its periphery, is a gas chamber with gas outlets

Claims (1)

Formula of the invention A recuperator comprising a distribution chamber with gas outlet openings equipped with variable-length nozzles directed to a heat transfer wall, characterized in that, in order to increase efficiency by reducing thermodynamic heat losses during heating of the air, the nozzles are arranged with increasing length from the center of the duct to its the periphery. Compiled by V. Moiseev Editor Tehred M. Morgenthal Corrector T. Paly Order 3539 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035. Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.