JPS5827202Y2 - waste heat boiler - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a waste heat boiler.

Energy resources are limited, and efforts must be made to reduce total consumption by making the most effective use of them.

Recovering and using waste heat is one way to achieve this.

When recovering waste heat, the heat source is often gas, and in this case, the utilization process often requires that the waste heat be recovered in the form of steam using a waste heat boiler.

However, in waste heat boilers, forced convection heat transfer is the main method of heat transfer between the gas and the heat transfer surface, so in the normal method, the heat transfer coefficient is It is difficult to increase the size, leading to an increase in the heat transfer area, which reduces the economic efficiency of waste heat recovery and utilization.

In order to overcome this, it is necessary to improve economic efficiency by making full use of special accelerated heat transfer and enlarged heat transfer surface technologies of forced convection heat transfer.

It is well known that in a fluidized bed as a reactor, the heat transfer coefficient between gas and a heat transfer tube installed in the bed for the purpose of removing reaction heat is extremely large.

This is used in a waste heat boiler, and the challenge here is to minimize the pressure loss on the gas side.

Therefore, in this invention, multiple partition plates are provided in the gas flow path,
A gas distribution plate is provided between these partition plates, and on these gas distribution plates, a group of heat exchanger tubes with fins are arranged horizontally and in only one row in the vertical direction. A water supply pipe is connected to one end of the lower multi-stage heat exchanger tube group among the multiple stage heat exchanger tube groups, and the other end is connected to the steam/water separator, and the upper The present invention proposes a waste heat boiler in which the heat transfer tubes of the remaining stages are connected to the upper end of the steam/water separator.

Here, the range in which the heat exchanger tube can be immersed in the fluidized bed is, for example, for a 25.4φ heat exchanger tube, the height of the fluidized bed is about 50 mm, and the fluidizing particles are fine sand (average particle size 0. 5tIrln) or the like.

Furthermore, in order to keep the heat exchanger tubes horizontal, the circulation of water should be a forced circulation method, and it would be more advantageous to use a heat exchanger tube with fins as the heat exchanger tube.

According to the waste heat boiler of the present invention as described above, the following advantages can be obtained.

0 The heat transfer coefficient between the horizontal heat transfer tube and the gas in the shallow fluidized bed is always large, and the heat transfer area can be greatly reduced.

0 Dust does not adhere to the heat transfer surface and there is no increase in heat transfer resistance due to dirt.

0 By adopting a shallow fluidized bed, the pressure loss is tolerable (for example, 50 mmAq + gas distribution plate 2 in the fluidized bed)
0111IllAq).

0 By employing a group of heat transfer tubes with fins, the heat transfer area can be increased, and the fluidization state can be further improved, so that the heat transfer coefficient can be further improved.

0 Superheated steam can be obtained by passing the steam separated by the steam separator through the heat transfer tube (super heater) again.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 1 denotes a main body having a gas port 2 on the lower end side and a gas outlet 3 on the other side of the upper end, and a gas flow path 4 formed inside the main body is divided vertically into a plurality of sections by a plurality of partition plates 5. There is.

Each of the partition plates 5 has an upright portion 6 on the gas outlet 3 side, and a hanging portion 1 on the other gas outlet 2 side.

A gas dispersion plate 9 having a large number of holes 8 is provided over the opposing rising part 6 and hanging part 1, and on each dispersion plate 9, 10 groups of heat transfer tubes are arranged horizontally and Only one row is arranged in the vertical direction.

One end of the heat exchanger tubes 10 except for the uppermost heat exchanger tube 10A communicates with the water supply pipe 12 from the circulation pump 11, and the other end communicates with the piping 1.
3 to the upper part of the steam/water separator 14.

The lower part of the steam/water separator 14 communicates with the circulation pump 11, and is provided with a water amount detection device 15 for the steam/water separator 14, which automatically controls the pulp 16 to detect the amount of water in the water separator 14.
The water supply pipe 12 is configured to supply water from the water supply pipe 12 to the water supply pipe 12.

The uppermost heat exchanger tube 10A is formed into a super heater,
The other end communicates with the upper end of the steam/water separator 14, and one end leads to the supply source.

An economizer 18 is disposed at the gas outlet 3, and water is supplied to the pump 19, and its drainage water reaches the make-up water pipe 17.

On each of the gas distribution plates 9, the layer height is the same as that of the heat exchanger tube group 1.
A small fluidized bed 20 is formed in which only 0°10A is embedded.

Note that 21 indicates a large number of fins attached to each heat transfer tube 10.1OA.

According to this embodiment, the exhaust gas A from the gas population 2 to the gas outlet 3 via the gas flow path 4 first flows through the holes 8 of the gas distribution plate 9.
The heat exchanger tubes i0. The IOA heats the feed water therein and the gas outlet 3 heats the feed water flowing through the economizer 18.

Therefore, the water supplied from the circulation pump 11 is heated and evaporated while being forcibly transported through each heat transfer tube 10, and the hot water separated in the steam/water separator 14 is reused, and the separated steam is transferred to the uppermost stage. While flowing through the heat exchanger tube 10A1, that is, the super heater, it is further heated and turned into superheated steam B, which is taken out.

On the other hand, the hot water heated by economizer 18 is heated by pulp 1.
An appropriate amount is supplied to the water supply pipe 12 via 6.

According to the waste heat boiler shown in the example, when heat is recovered from exhaust gas A with an exhaust gas amount of 480,000 N-m"/h and an exhaust gas temperature of 650°C, the pressure is about 35 KIi/i and the temperature is 350°C.
About 100 tons/h of superheated steam B is generated.

At this time, the heat exchanger tube 10. As IOA, outer diameter is 25.4φ
STB tube of 50.8' and thickness 3WI! About 400 N-fins (fin pitch 100 fina/m) 21 with a length of about 86 m are used in the evaporator section, and about 100 pieces are used in a part of the super heater.

As shown in the above embodiment, by stacking a plurality of parallel fluidized beds 20 in terms of gas flow, the overall compactness can be achieved, and one or a part of the parallel fluidized beds 20 can be used as a superheater. Superheated steam can be obtained by doing this.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic longitudinal sectional front view, FIG. 2 is a schematic longitudinal sectional side view, and FIG. 3 is a vertical sectional side view of main parts. 1...Main body, 2...Gas inlet, 3...
...Gas outlet, 4...Gas flow path, 5...
...Partition plate, 9...Gas distribution plate, 10,10
A...Heat transfer tube, 18...Economizer-120...Fluidized bed, 21...Fin, A-...Exhaust gas, B... ...Superheated steam.

Claims (1)

[Scope of utility model registration request] A plurality of partition plates are provided in the gas flow path, a gas distribution plate is provided between these partition plates, a group of heat transfer tubes with fins are arranged horizontally and in only one row in the vertical direction on these gas distribution plates, and the gas A small fluidized bed is formed on the distribution plate, the height of which is only enough to embed the heat exchanger tube group, and a water supply pipe is communicated with one end of the lower multi-stage heat exchanger tube group among the multiple stages of the heat exchanger tube group. 1. A waste heat boiler, characterized in that the other end of the boiler is connected to a steam separator, and the heat exchanger tubes in the remaining upper stages are connected to the upper end of the steam separator.