JPH05180403A - Exhaust heat collection device - Google Patents

Abstract

PURPOSE:To avoid the fluctuations in the water level in a drum or burning of a heat exchanger element by dividing a heat exchanger chamber into a plurality of chambers and laying out the heat exchanger element in an elevation below the water level of a steam separator drum. CONSTITUTION:The interior of a heat exchanger chamber 1 is divided into chambers 22 and 23 by means of a partitioning wall 21. An inlet duct 3 is installed to one chamber so as to introduce an exhaust gas while an outlet duct 6 is installed to the other chamber so as to discharge the exhaust gas. It is arranged that the exhaust gas be discharged after having heat-exchanged with a heat exchanger element 2 in each divided chamber one after another. Furthermore, the heat exchanger element 2 is laid out in such a fashion that it may be positioned in an elevation below the water level. of a steam separator 12. Since the heat exchanger element 2 is always positioned below the water level of the steam separator drum 12, it is possible to minimize the fluctuations in a weight of the steam separator 12 when starting or halting the operation. Furthermore, this construction makes it possible to maintain the steam separator drum which is constantly filled with boiler water and hence protect the heat exchanger element 2 from burning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust heat recovery device for obtaining hot water or generating steam by exhaust heat from various heat sources.

[0002]

2. Description of the Related Art Exhaust gas boilers and economizers are well known as exhaust heat recovery devices. FIG. 4 is a configuration explanatory view showing a part of a conventional exhaust gas boiler in cross section. That is, the heat exchange element 2 is disposed inside the heat exchange chamber 1, and the lower part of the heat exchange chamber 1 is provided with the inlet damper 4 and the expansion 5 which are connected to the gas inlet duct 3. On the other hand, in the upper part of the heat exchange chamber 1, a gas outlet duct 6 is provided.
An outlet damper 7 and an expansion 8 are provided in series. The gas inlet duct 3 and the gas outlet duct 6 are connected by a bypass duct 9, and the bypass duct 9 includes two expansions 1.
0 and the bypass damper 11 are provided between them.

Further, outside the heat exchange chamber 1, a steam separation drum 12 for circulating can water in the heat exchange element 2.
Is installed, and the steam separation drum 12 is a circulation pump 1
3 is connected to the inlet header 14 of the heat exchange element 2 via an outlet header 15 of the heat exchange element 2.
Is connected to the steam / water separation drum 12 to form a circulation system for can water. The steam separated by the steam separation drum 12 is sent to a process line or the like through the steam pipe 16.

In such a conventional exhaust gas boiler,
The high-temperature exhaust gas is introduced from the gas inlet duct 3 into the lower part of the heat exchange chamber 1, exchanges heat while rising upward around the heat exchange element 2, and is discharged from a stack (not shown) through the gas outlet duct 6. . On the other hand, the steam separation drum 12 is supplied with water from the outside, and the water is introduced into the heat exchange element 2 via the circulation pump 13 and the inlet header 14. Then, the steam generated by heat exchange with the exhaust gas returns from the outlet header 15 of the heat exchange element 2 to the steam separation drum 12, and is separated into steam and can water by the steam separation drum 12, and the separated steam is It is sent to a process line or the like through the steam pipe 16. Moreover, the can water after separating the steam is recirculated to the heat exchange element 2 by the circulation pump 13.

A bypass duct 9 connecting the gas inlet duct 3 and the gas outlet duct 6 is provided for controlling the pressure of the heat exchange chamber 1. Normally, the bypass damper 11 is slightly opened to open the inlet duct. A part of the exhaust gas introduced from 3 is bypassed and the pressure in the heat exchange chamber 1 is controlled to be constant.

[0006]

By the way, in the exhaust gas boiler intended to save energy, the exhaust gas of the low heat source is used, and in this case, the energy density of the exhaust gas is small and the heat exchange element 2 is used. The heat transfer area must be increased. Therefore, the height of the heat exchange element 2 becomes high, and the outlet header 15 is to be installed at a position considerably higher than the water level of the steam separation drum 12. Therefore, at the time of starting or stopping the boiler, there is a problem that the fluctuation of the water level in the steam / water separation drum 12 becomes extremely large, which is inconvenient in operation. Further, when the circulation pump 13 is stopped immediately after the engine is stopped, the upper part of the heat exchange element 2 becomes an empty can, so that the sticky suit attached to the heat exchange element 2 ignites and heats up. There is a problem that the replacement element 2 may be burnt out.

[0007]

According to the present invention, a heat exchange element is provided inside a heat exchange chamber having an inlet and an outlet for exhaust gas, and a steam separation drum for circulating can water is connected to the heat exchange element. In an exhaust heat recovery device for recovering exhaust heat from exhaust gas, the inside of the heat exchange chamber is partitioned into a plurality of chambers, one of the partitioned chambers is provided with an exhaust gas inlet, and the other chamber is provided with an exhaust gas outlet, The introduced exhaust gas is sequentially discharged through each partitioned chamber, and the heat exchange element is arranged below the water level of the steam separation drum.

[0008]

[Operation] According to the above means, the height of the heat exchange element is reduced by the amount of partitioning the inside of the heat exchange chamber into a plurality of chambers, and the heat exchange element of the exhaust heat recovery device is always steam-water. Since it is located below the water level of the separation drum, the heat exchange element is always filled with can water, and therefore the boiler start / stop, circulation pump start / stop and fluctuation of the water level in the drum at the time of gas injection It is no longer necessary to take special measures to avoid burnout of the heat exchange element.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exhaust heat recovery system according to the present invention will be described in detail below with reference to FIGS. In these figures, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a first example of an exhaust heat recovery apparatus according to the present invention.
FIG. 3 is a configuration explanatory view showing a part of the embodiment of FIG. That is, in the present invention, the inside of the heat exchange chamber 1 is vertically divided into two parts by the partition wall 21 to form the first section 22 and the second section 23, and spaces are formed at the top and bottom of the heat exchange chamber 1. Thus, the heat exchange element 2 is arranged in the intermediate portion. The heat exchange element 2 is the partition wall 2
1 through the first section 22 and the second section 23
It is located in. The gas inlet duct 3 is connected to the bottom of the first section 22, and the gas outlet duct 6 is connected to the bottom of the second section 23.
Further, a shut-off damper 24 is provided above the partition wall 21 in the heat exchange chamber 1, and a bypass damper 25 is also provided below the partition wall 21.

The inlet header 1 of the heat exchange element 2
4 is connected to the steam / water separation drum 12 via the circulation pump 13, and the outlet header 15 of the heat exchange element 2 is also connected to the steam / water separation drum 12 to form a circulation system of the can water. . The heat exchange element 2 is arranged below the water level L of the steam separation drum 12.

In the exhaust heat recovery system of the present invention thus constructed, the shut-off damper 24 is fully opened and the bypass damper 25 is fully closed to introduce the exhaust gas from the gas inlet duct 3 into the heat exchange chamber 1. . Therefore, the exhaust gas rises in the first section 22, and the shutoff damper 24
After entering the second section 23, the second section 23
And is discharged from the bottom gas outlet duct 6. Then, as the exhaust gas passes from the inside of the first section 22 to the inside of the second section 23, heat exchange with the can water in the heat exchange element 2 is performed. The action of the circulation system between the heat exchange element 2 and the steam separation drum 12 is the same as the conventional one. Although the bypass damper 25 is normally fully closed, the pressure of the exhaust gas introduced into the heat exchange chamber 1 can be adjusted by slightly opening it.

When the exhaust heat recovery device is not used, the shutoff damper 24 is fully closed and the bypass damper 25 is used.
By fully opening the exhaust gas introduced into the heat exchange chamber 1 from the gas inlet duct 3 without passing through the first section 22 and the second section 23, the gas outlet duct 6
Will be totally discharged from. That is, the exhaust gas introduced into the heat exchange chamber 1 bypasses the heat exchange element 2 and is discharged.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 is a sectional view taken along the line AA of FIG. In this embodiment, a partition wall 31 that divides the interior of the heat exchange chamber 1 into two parts in the vertical direction is arranged in a direction perpendicular to the partition wall 21 in FIG. Therefore, the heat exchange element 2 does not need to penetrate the partition wall 31, and the first section 22 and the second section 23 can be formed in the heat exchange chamber 1. Other configurations and operations are similar to those of the first embodiment shown in FIG.

In the first and second embodiments, the example in which the heat exchange chamber is divided into two is shown, but the present invention is not limited to this, and the heat exchange chamber is divided into a plurality of sections, preferably. It may be divided into an even number of sections.
For example, the heat exchange chamber may be divided into four or more even numbers so that the sections are arranged in a straight line, or the heat exchange chamber may be divided into four in a square shape.

Also, in the illustrated embodiment, the gas inlet duct 3
Although the gas outlet duct 6 is provided in the lower portion of the heat exchange chamber 1, it may be provided in the upper portion of the heat exchange chamber 1. In this case, the shut-off damper 24 is arranged below the partition wall 21, and the bypass damper 25 is arranged above the partition wall 21.

In any case, the best mode of the structure in the heat exchange chamber is, as illustrated in FIGS. 1 and 3, a gas inlet duct 3, a gas outlet duct 6 and a bypass damper 25.
Are located on the same side of the upper or lower part of the heat exchange chamber 1, and the shut-off damper 24 is located on the partition wall on the opposite side.

[0018]

As described in detail above, according to the present invention, the height of the heat exchange element is reduced by the amount of dividing the inside of the heat exchange chamber into a plurality of sections and the heat of the exhaust heat recovery device is reduced. Since the exchange element is always positioned below the water level of the steam / water separation drum, fluctuations in the water level of the steam / water separation drum at the time of starting and stopping can be extremely reduced. Also, since the heat exchange element is always filled with canned water and a part of the heat exchange element does not become locally high in temperature, adhesion of the sticky suit to the heat exchange element or sticky suit It is possible to eliminate the risk of ignition and therefore burning of the heat exchange element. Furthermore, as the height of the heat exchange element is lower, the height of the heat exchange chamber is also lower, and each damper can be housed in the device at one time, so operation and maintenance inspection is easy, the entire device is compact, and it is also earthquake resistant. Provided is an exhaust heat recovery device which has remarkable effects such as improvement.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view partially showing a cross section of an embodiment of an exhaust heat recovery apparatus according to the present invention.

FIG. 2 is a structural explanatory view, partly in cross section, of a second embodiment of the present invention.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a configuration explanatory view showing a part of a conventional exhaust heat recovery device in cross section.

[Explanation of symbols]

 1 heat exchange chamber 2 heat exchange element 3 gas inlet duct 6 gas outlet duct 12 steam separation drum 21 partition wall 22 first section 23 second section

Claims (1)

[Claims] 1. An exhaust heat recovery apparatus comprising a heat exchange element inside a heat exchange chamber having an inlet and an outlet for exhaust gas, and a steam separation drum for circulating can water is connected to the heat exchange element. The inside of the exchange chamber is divided into multiple chambers, one of the partitioned chambers is provided with an exhaust gas inlet, and the other chamber is provided with an exhaust gas outlet, and the introduced exhaust gas is sequentially discharged through the partitioned chambers. The exhaust heat recovery device is characterized in that the heat exchange element is arranged below the water level of the steam separation drum.