JP3783417B2 - Reheater for gas gas heater in flue gas treatment facility - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reheater for a gas gas heater in a flue gas treatment facility.
[0002]
[Prior art]
In general, since exhaust gas discharged from a coal fired boiler or the like contains sulfur oxides, a smoke treatment facility is installed on the downstream side of the coal fired boiler, etc. In a smoke desulfurization apparatus, exhaust gas and an absorbing liquid are brought into gas-liquid contact to remove sulfur oxides contained in the exhaust gas.
[0003]
The outlet gas of the wet flue gas desulfurization device is generally reduced to about 50 [° C.] and is substantially saturated, and when this outlet gas is discharged as it is from the chimney into the atmosphere, white smoke is generated, The outlet gas is reheated by using a heat medium circulation type gas gas heater provided with a heat recovery device and a reheater.
[0004]
FIG. 3 shows an example of a conventional flue gas treatment facility, wherein 1 is a wet flue gas desulfurization device, and a gas gas heater for recovering the heat of exhaust gas is disposed upstream of the wet flue gas desulfurization device 1. 2 and a gas gas heater for reheating the outlet gas of the wet flue gas desulfurization device 1 by the heat recovered by the heat recovery device 3 on the downstream side of the wet flue gas desulfurization device 1 2 reheaters 4 are installed.
[0005]
The heat recovery device 3 and the reheater 4 of the gas gas heater 2 are connected to each other by connecting pipes 5 and 6 through which a heat medium flows, and a pump for circulating the heat medium in the middle of the connecting pipe 5. 7 is provided.
[0006]
Further, the reheater 4 is generally configured by arranging a heat transfer tube 10 composed of a large number of finned tubes 9 inside the casing 8 as shown in FIG. 4 in order to make the heat transfer surface compact. have. Although not shown, the heat recovery unit 3 of the gas gas heater 2 has a configuration in which a heat transfer tube made up of a number of finned tubes is provided inside the casing, as in the case of the reheater 4. is doing.
[0007]
In the case of the conventional flue gas treatment equipment as described above, the exhaust gas discharged from a coal fired boiler or the like (not shown) is subjected to wet flue gas desulfurization after heat is recovered by the heat medium in the heat recovery unit 3 of the gas gas heater 2. The sulfur oxide contained in the exhaust gas is removed by the gas-liquid contact between the exhaust gas and the absorption liquid in the wet flue gas desulfurization apparatus 1, and the sulfur oxide is removed in the wet flue gas desulfurization apparatus 1. The exhausted gas is reheated by the heat recovered by the heat recovery unit 3 in the reheater 4 of the gas gas heater 2 and discharged from the chimney 11 to the atmosphere.
[0008]
Here, since the finned tube 9 is adopted as the heat transfer tube 10 of the reheater 4 of the gas gas heater 2, the substantially saturated exhaust gas discharged from the wet flue gas desulfurization device 1 is slightly moistened. When flowing into the reheater 4 of the gas gas heater 2, dust or the like contained in the exhaust gas adheres and accumulates between the fins of the finned tube 9, and the pressure loss in the reheater 4 of the gas gas heater 2 increases. There was a fear.
[0009]
For this reason, conventionally, as shown in FIG. 3, a steam gas heater 12 is provided on the inlet side of the reheater 4 of the gas gas heater 2, and the temperature of the exhaust gas is raised by the steam gas heater 12. As a result, the exhaust gas flowing into the air is dried, so that dust or the like is prevented from being deposited between the fins of the finned tube 9 of the reheater 4, or the reheater 4 of the gas gas heater 2. When a soot blower (not shown) is provided at the inlet of the reheater 4 and dust or the like adheres and accumulates between the fins of the finned tube 9 of the reheater 4, steam or the like is injected from the soot blower, It has been practiced to remove dust and the like deposited between the fins.
[0010]
[Problems to be solved by the invention]
However, as described above, the provision of the steam gas heater 12 on the inlet side of the reheater 4 of the gas gas heater 2 requires a steam supply system, a drain system, etc. in addition to the steam gas heater 12, and the equipment cost is high. The system also had the disadvantage that it was complicated.
[0011]
In addition, when a soot blower is disposed at the inlet of the reheater 4 of the gas gas heater 2, a soot blower and its steam supply system, as well as a steel frame and a scaffold for the soot blower are required, and the equipment cost is also high and the system is complicated. It had the disadvantage of becoming.
[0012]
In view of such circumstances, the present invention has a simple structure without providing a steam gas heater, a soot blower, or the like, and can minimize an increase in pressure loss in the reheater of the gas gas heater, thereby reducing the equipment cost. An object of the present invention is to provide a reheater for a gas gas heater in a possible flue gas treatment facility.
[0013]
[Means for Solving the Problems]
The present invention is a reheater for a gas gas heater in a flue gas treatment facility, which is installed on the downstream side of a wet flue gas desulfurization apparatus and in which a heat transfer pipe composed of a number of finned pipes is disposed inside a casing,
The present invention relates to a reheater of a gas gas heater in a flue gas treatment facility characterized in that the heat transfer tube disposed at the inlet of the reheater is constituted by a bare tube without fins.
[0014]
In the reheater of the gas gas heater in the flue gas treatment facility, it is effective to make the arrangement pitch of the bare tubes denser than the arrangement pitch of the finned tubes.
[0015]
According to the above means, the following operation can be obtained.
[0016]
When the substantially saturated exhaust gas discharged from the wet flue gas desulfurization apparatus flows into the reheater of the gas gas heater in a slightly moist state, the substantially saturated state is caused by a bare tube as a heat transfer tube disposed at the inlet portion. Since the exhaust gas is heated and dried, it passes through the area where the finned tube of the reheater is placed, so that dust and the like are prevented from adhering and accumulating between the fins of the finned tube Is done.
[0017]
On the other hand, since the exhaust gas passes through the surface of the bare tube before it becomes dry, dust or the like slightly adheres to it, but the dust or the like attached to the surface of the bare tube has no fins. Therefore, it does not grow and accumulate greatly, and it is possible to cope with it by washing with water when the can is stopped during periodic inspections.
[0018]
As a result, an increase in pressure loss in the reheater of the gas gas heater can be minimized.
[0019]
In the reheater of the gas gas heater in the flue gas treatment facility, if the arrangement pitch of the bare pipe is made denser than the arrangement pitch of the finned pipe, the heat transfer performance is further improved and the size of the reheater is reduced. it can.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
FIG. 1 shows an example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 3 and 4 denote the same components, and the basic configuration is shown in FIGS. As shown in FIG. 1, the heat transfer tube 10 disposed at the inlet of the reheater 4 is composed of a bare tube 13 without fins. It is in the point.
[0022]
Next, the operation of the illustrated example will be described.
[0023]
When the substantially saturated exhaust gas discharged from the wet flue gas desulfurization apparatus 1 flows into the reheater 4 of the gas gas heater 2 in a slightly wet state, the bare tube 13 as the heat transfer tube 10 disposed at the inlet portion thereof. Thus, the substantially saturated exhaust gas is heated and dried, and then passes through the region where the finned tube 9 of the reheater 4 is disposed. And the like are prevented from being deposited.
[0024]
On the other hand, since the exhaust gas passes through the surface of the bare tube 13 before it becomes dry, dust or the like slightly adheres to it, but the dust or the like attached to the surface of the bare tube 13 Therefore, it does not grow and accumulate greatly, and it can be sufficiently handled by washing with water when it is stopped during periodic inspections.
[0025]
As a result, an increase in pressure loss in the reheater 4 of the gas gas heater 2 can be minimized.
[0026]
In this way, an increase in pressure loss in the reheater 4 of the gas gas heater 2 can be minimized with a simple structure without providing a steam gas heater or a soot blower, and the equipment cost can be reduced.
[0027]
FIG. 2 shows another example of the embodiment of the present invention. In the figure, the parts denoted by the same reference numerals as those in FIG. 1 represent the same thing, and the arrangement of the bare tube 13 is eliminated by eliminating the fins. The pitch is made denser than the arrangement pitch of the finned tubes 9.
[0028]
In the case of the example shown in FIG. 2, as in the case of the example shown in FIG. 1, the substantially saturated exhaust gas discharged from the wet flue gas desulfurization apparatus 1 flows into the reheater 4 of the gas gas heater 2 in a slightly moist state. In this case, the substantially saturated exhaust gas is heated by the bare tube 13 as the heat transfer tube 10 disposed at the inlet, and the finned tube 9 of the reheater 4 is disposed after being dried. As the dust passes through the region, dust and the like are prevented from adhering and accumulating between the fins of the finned tube 9, while the exhaust pipe passes on the surface of the bare tube 13 before it becomes dry. Therefore, dust or the like slightly adheres to the surface of the bare tube 13, but the dust does not grow and accumulate due to the absence of fins. It is possible to respond enough by washing with water occasionally, as a result, Increase in pressure loss in the reheater 4 Sugasuhita 2 and thus be minimized.
[0029]
Moreover, in the example shown in FIG. 2, the arrangement pitch of the bare tubes 13 is made denser than the arrangement pitch of the finned tubes 9, so that the heat transfer performance is further improved compared to the example shown in FIG. The size of the reheater 4 can also be reduced.
[0030]
Thus, in the case of the example shown in FIG. 2, an increase in pressure loss in the reheater 4 of the gas gas heater 2 can be minimized with a simple structure without providing a steam gas heater, a soot blower, etc. The cost can be reduced and the heat transfer performance can be improved.
[0031]
In addition, the reheater of the gas gas heater in the flue gas treatment facility of the present invention is not limited to the above illustrated example, and various changes can be made without departing from the scope of the present invention. is there.
[0032]
【The invention's effect】
As described above, according to the reheater of the gas gas heater in the flue gas treatment facility according to claim 1 of the present invention, the reheater of the gas gas heater has a simple structure without providing a steam gas heater or a soot blower. An increase in the pressure loss of the gas gas heater can be minimized, and an excellent effect that the equipment cost can be reduced can be obtained. Further, the reheater of the gas gas heater in the flue gas treatment equipment according to claim 2 of the present invention According to the invention, in addition to the above-described effects, an excellent effect that heat transfer performance can be improved can be achieved.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an example of an embodiment for carrying out the present invention.
FIG. 2 is a side sectional view of another example of an embodiment for carrying out the present invention.
FIG. 3 is an overall schematic configuration diagram showing an example of a conventional smoke treatment facility.
FIG. 4 is a side sectional view of an example of a reheater of a conventional gas gas heater.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wet flue gas desulfurization apparatus 2 Gas gas heater 3 Heat recovery device 4 Reheater 8 Casing 9 Tube with fin 10 Heat transfer tube 13 Bare tube

Claims (2)

A reheater for a gas gas heater in a flue gas treatment facility installed on the downstream side of a wet flue gas desulfurization apparatus and provided with a heat transfer pipe consisting of a number of finned pipes inside the casing,
A reheater for a gas gas heater in a flue gas treatment facility, wherein a heat transfer tube disposed at an inlet of the reheater is a bare tube without fins. The reheater of a gas gas heater in a flue gas treatment facility according to claim 1, wherein the arrangement pitch of the bare pipe is made denser than the arrangement pitch of the finned pipe.

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