JPS59153095A - Heat exchanger - Google Patents

Abstract

PURPOSE:To facilitate inspection and repair work of a heat exchanger, by connecting heat transfer pipes to each other by a lower header to form a group of heat transfer pipes, and by forming working spaces for a worker to allow him enter into them when he provides service to the group of heat transfer pipes. CONSTITUTION:a plurality of heat transfer pipes 11 being formed in the shape of nearly inverted U are connected in the longitudinal direction of an end header 12. ON the other hand, a plurality of other heat transfer pipes 13 being formed in the shape of nearly inverted U in the same manner of the heat transfer pipes 11 are connected in the longitudinal direction of another end header 14. The other ends of heat transfer pipes 11 and 13 are respectively connected to an intermediate header 15, by which all heat transfer pipes 11 and 13 are communicated. Working spaces 16-18 are provided for an operator to allow him enter among those heat transfer pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a heat transfer tube of a heat exchange device, and particularly to the structure of a device that can be effectively used as a superheater of a waste heat recovery boiler.

With recent changes in the fuel situation, higher power generation efficiency is required in thermal power plants, and one way to achieve this is to construct combined cycle power plants that combine gas turbines and steam turbines. ing. A combined cycle power plant first generates electricity using a gas turbine (
The heat in the waste gas discharged from the gas turbine is recovered in a waste heat recovery boiler, and the steam generated in the boiler G is used to drive a steam turbine to generate electricity.

FIG. 1 shows an example of a waste heat recovery boiler. In the figure, turbine exhaust gas G flows into the waste heat recovery boiler main body 1, first into the superheater 2. It passes through a high-pressure evaporator 3a and reaches a denitrification device 4, where the nitrogen oxides (NOx) contained therein are removed. Denitration equipment 4
The exhaust gas that exits is sent to another high-pressure evaporator 3b and a high-pressure economizer 5. Low pressure evaporator6. It passes through the low pressure economizer 7 and exchanges heat with the internal fluid in each heat transfer tube.

FIG. 2 shows the structure of a superheater among the heat exchanger tube group described above.

The superheater 2 has heat transfer tubes 1 between the upper header 8 and the lower header 9.
It is constructed by placing 0.

Here, the superheater 2 is exposed to the highest temperature exhaust gas and placed in a harsh environment. Furthermore, since the internal fluid is high-temperature, high-pressure steam, if the superheater is damaged, there is a risk of a major accident. Therefore, it is necessary to particularly carefully inspect the superheater 2. However, in the structure of a conventional superheater, as shown in the figure, the heat exchanger tubes 10 are arranged closely, making it difficult or impossible for workers to enter the inside of the group of heat exchanger tubes, making inspection and repair work extremely difficult. I was doing it.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a heat exchanger tube device, particularly a device suitable for a superheater, which has a structure that allows easy inspection and repair work.

In short, the present invention is a heat exchanger tube device in which the upper header is eliminated, each heat exchanger tube is connected by a lower header to form a heat exchanger tube group, and a space is formed for a worker to enter the heat exchanger tube group.

Examples of the present invention will be described below.

In FIGS. 3 and 4, numeral 11 is a heat exchanger tube formed in a substantially inverted U shape, and a large number of these heat exchanger tubes are connected to an end header (
right header) 12 in the longitudinal direction. Reference numeral 13 designates another inverted U-shaped heat exchanger tube formed in a substantially inverted U shape similarly to the heat exchanger tube 11 described above, and one end thereof is connected to a header (left header) 14 . Similarly, a large number of heat exchanger tubes 13 are connected to another end header 14 in the longitudinal direction so as to be parallel to each other.

The other end of each of these heat exchanger tubes 11 and 13 is connected to an intermediate header 15, and the respective heat exchanger tubes 11 and 13 are communicated with each other via this intermediate header 15. In the illustrated example, two sets of substantially inverted U-shaped heat exchanger tube groups are connected via the intermediate header 15, but the number of intermediate headers may be increased to connect three or more sets of heat exchanger tubes.

By configuring as described above, spaces 16, 17, and 18 are formed between each heat exchanger tube into which the worker 20 can enter. The heat transfer tube group described above is most effective when used as a superheater 7, but is not limited to this and can also be used as an evaporator or the like.

In the heat exchanger tube group having the above configuration, if it becomes necessary to inspect the heat exchanger tube group, the operator 2
o enters spaces 16, 17, and 18 and performs inspection and welding repair work.

In addition, the drain generated in the heat transfer tube when the device is stopped can be easily discharged to the outside because all the headers are located at the bottom, resulting in a so-called drainable structure.

By implementing the present invention, inspection and repair work on a group of heat exchanger tubes such as a superheater can be performed easily and reliably, and the safety of the heat exchange device can be greatly improved.

In addition, the drain generated inside can be almost completely discharged to the outside.
The device can also be restarted easily.

[Brief explanation of the drawing]

Figure 1 is a side view of a waste heat recovery boiler, Figure 2 is a side view of a conventional superheater, Figure 3 is a side view of a group of heat transfer tubes according to the present invention, and Figure 4 is a perspective view of Figure 3. be. 12.14 Old end header 11.13 Heat transfer tube 15 Intermediate header 16, 17.18 Mountain space 20 Worker

Claims (1)

[Claims] 1. In a system in which a large number of heat exchanger tubes are connected by a header to form an integrated heat exchange device, each heat exchanger tube is formed into a substantially inverted U shape, and each of the plurality of inverted U-shaped heat exchanger tubes is connected to a gas A set of heat exchanger tubes is formed by arranging them almost parallel to each other according to the flow, and the plural sets of inverted U-shaped heat exchanger tubes are connected by left and right end headers and an intermediate header located at the bottom of the heat exchanger tubes, and between each heat exchanger tube. A heat exchange device characterized by forming a space in which personnel can move.