JPS62792A - Non-leak trisector air preheater - Google Patents

Abstract

PURPOSE:To make air leak zero by a method wherein the upper header of one heating side heat element and the upper header of one cooling side heat element are connected through an ascending pipe and, further, the lower headers of both heat elements are connected mutually by a water descending pipe while a duct, in which the cooling side heat element is arranged, is provided with a partitioning wall so as to flow two fluids. CONSTITUTION:The air preheater is arranged with a combustion gas section 1 at the lower side and secondary as well as primary air sections 2, 3 at the upper side thereof and respective heat transfer sections are arranged with finned tubes or bare tubes while respective tubes are connected to the headers 6, 7, 8, 9 arranged in each heating and cooling side in up-and-down relation. Further, the header 6 is connected to the header 8 through a water-lowering tube 4 while the header 7 is connected to the header 9 through the ascending tube 5. In a closed loop, water (or heat medium) repeats evaporation and condensation in heating side and cooling side and forms a natural circulating series, whereby the amount of heat, absorbed in the heating side, is released in the cooling side and heat transfer may be effected without contacting the combustion gas with air at all.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is utilized in the technical field of eliminating pnea leakage in an air preheater used in a steam engine boiler.

Conventional technology: Conventionally, when a cold primary system (mil air system) is used in a coal-fired boiler, a tri-sector type of Jungstrom air preheater is used. In the case of the tri-sector type, the pressure difference between the primary air side and the gas side becomes extremely large, so this tendency becomes even greater.

Problems to be Solved by the Invention The present invention is a Jungstrom air preheating system in which a heat transfer surface (heating element) rotates between a heating side (combustion gas side) and a cooling side (air side). Near leaks inevitably occur in equipment, but they are basically divided into two types: (b) installation leaks, and (b) direct leaks.

The amount of leakage depends on the size of the air preheater, but?
-15fi, which has many disadvantages such as increased capacity of FD fan (forced fan) and increased operating power.

In particular, in the case of the trisector Jungström equation, 1°
Since the pressure difference (draft difference) between the secondary air side and the combustion gas side is large, the amount of leakage becomes particularly large, so the present invention aims to reduce these amounts of leakage to zero.

Means for Solving the Problems The present invention takes the following measures in order to solve the above-mentioned problems. That is, the upper header of one heating side heat element and the upper header of one cooling side heat element and qν are connected by a riser pipe, and further, the lower headers are connected with each other by a downcomer pipe, and the cooling side heat element is connected to the piping. A partition wall is provided to allow the flow of the duct fluid.

According to the means described above, the combustion gas side, the primary air side, and the secondary air side are completely separated by using the fluid circulation system, so in principle, near leakage can be eliminated. You can.

Example Next, regarding an example of the present invention, FIG. 1 (front view showing the configuration of a non-leak tri-sector air preheater), FIG. 2 (side view thereof), and FIG. 3 (fluid flow system diagram) Please refer to the following for details.

In the figure, 1 is the combustion gas side (heating side) heat transfer section, 2 is the secondary air heat transfer section (cooling side), and 3 is 1
Next air heat transfer section (cooling side), 4 is downcomer pipe, 5 is riser pipe, 6 is heating side section lower header, 7 is heating side section upper header, 8 is cooling side section lower header, 9 is cooling side section upper part Header, 10 is heat transfer tube, 11 is water supply line, 12 is vent line, 13 is safety valve, 14 is water level gauge, 15 is drain line (water drain)
In FIG. 2, solid line arrows indicate the flow direction of air, and dashed line arrows indicate the flow direction of gas.

The air preheater is composed of three heat transfer sections: a combustion gas side section 1, a secondary air section 2, and a primary air section 3. An air section 2 and a primary air section 3 are arranged, and a finned tube or a bare tube is arranged in each heat transfer section, and the container tube has headers 6. arranged above and below on each heating side and cooling side. 7.8.9 and are connected to the lower header 8 of the Kushicon by a downcomer pipe 4, and the heating side section upper header 7 and the cooling side section upper header 9 are connected to each other by a riser pipe 5.

A water level gauge 14 is installed in each downcomer pipe 4.

At the bottom of the downpipe, there is a water supply line 11 and a drain line 1.
5 will be installed. On the other hand, a vent line 12 and a safety valve 13 are installed at the upper part of the riser pipe 5. Usually, water is used as the internal fluid, but in high-temperature regions, heat media other than water flooding are also used.

In the above closed loop, water (or heat medium) is.

By repeating evaporation and condensation on the heating side and cooling side, forming a natural circulation system, the amount of heat absorbed on the heating side is released on the cooling side, and the combustion gas and air never come into contact with each other. Heat transfer becomes possible.

The direction of flow of combustion gas and the direction of air flow are countercurrent, and according to each temperature level, the heat transfer section is divided into several independent blocks in the flow direction, and each block has internal Fluid pressure and temperature conditions are determined.

Effects of the Invention According to the non-leak tri-sector air preheater of the present invention, there is no leakage from the air side to the combustion gas side, so the amount of air passing through the forced draft fan of the boiler is reduced accordingly, and the draft fan It is possible to reduce the capacity and the power required for ventilation.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the configuration of the air preheater of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a fluid flow system diagram. 1. Combustion gas side (heating side) heat transfer section, 2..2
Secondary air heat transfer section (cooling side), 3...Primary air heat transfer section, 4...Down pipe, 5--Rising pipe, 6...Heating side section lower header, 7...Heating side section upper header, 8. Cooling side section lower header, 9
...Cooling side section upper header, 10...Heat transfer tube,
11・e Water supply line, 12・φ vent line (gas vent), 13・・Safety valve, 14・9 Water level gauge, 15--Drain Figure 1 Figure 2 II 3 Figure Tresi line

Claims (1)

[Claims] The upper header of one heating-side heat element and the upper header of one cooling-side heat element are connected by a rising pipe, and the lower headers are further connected by a downcomer pipe,
A non-leak tri-sector air preheater in which a partition wall is provided in a duct to which the cooling side heat element is piped so that two fluids flow.