JPH11211387A - Cooling device for hot water containing carbon dioxide - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent generation of algae attached to and formed on a filler of a cooling water tower by cooling water containing carbon dioxide gas. A cooling water tower for cooling a cooling water containing carbon dioxide gas which is brought into direct contact with a combustion exhaust gas in a gas-liquid contact tower and brought into contact with the atmosphere to cool the cooling water.
a, a plurality of cooling chambers 22, 23 provided with 25 b and 25 c,
24, these are arranged in parallel in the cooling water flow path, and the fans 26a, 26b, 26c of the respective cooling chambers are temporarily stopped in order, and the algae which adhere to the filler by the flowing high-temperature cooling water are removed. I let him die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cooling water circulation passage provided with a cooling water tower for cooling cooling water containing carbon dioxide gas by bringing the cooling water into contact with the atmosphere, thereby making it possible to remove algae adhering to the filler of the cooling water tower. And a cooling device.

[0002]

2. Description of the Related Art FIG. 3 shows a schematic configuration of a flue gas desulfurization facility. As shown in FIG. 3, in this desulfurization facility, the combustion exhaust gas discharged from the boiler 1 is desulfurized and washed through a wet absorption tower 2, and then the exhaust gas is cooled with cooling water through a gas-liquid contact tower 3 to lower the temperature of the exhaust gas. Let me
A method of reducing the moisture in the gas and discharging the gas from the gas-liquid contact tower 3 is employed.

[0003] The gas-liquid contact tower 3 is provided with a cooling device 4 for recirculating cooling water used for lowering the temperature of exhaust gas and finally releasing the heat to the atmosphere. In the cooling device 4, the cooling water heated by heat exchange with the exhaust gas in the gas-liquid contact tower 3 is sprinkled down from the upper part of the cooling water tower 5 to the filler 6, and is forcedly ventilated by a suction fan or the like. After cooling, it is collected in the lower water tank 7 and circulated again to the gas-liquid contact tower 3.

[0004]

In the cooling water tower 5, since the cooling water comes into contact with the atmosphere, the cooling water is neutralized with an alkali to prevent a small amount of SO2 or the like contained in the cooling water from coming into contact with the exhaust gas. It is common to use cooling water around PH7. When this substantially neutral cooling water passes through the cooling water tower 5, the cooling water in the cooling water tower 5 is filled due to contact with the atmosphere, the presence of light (such as sunlight), and the presence of a large amount of carbon dioxide in the cooling water. Algae is generated in the material 6 and gradually grows and adheres to the filler 6. In general, the filler 6 is formed by arranging a large number of corrugated thin plates. Therefore, when the amount of the filler increases due to adhesion and growth of algae, the thin plates are buckled and bent by their weight.
Then, there is a problem that the contact between the flow of the cooling water in the filler 6 and the atmosphere is poor and the cooling effect is deteriorated.

[0005] Further, the algae takes in some soot in the gas or dust in the atmosphere, and further blocks the filler 6, so that the replacement of the filler has been forced in about two years. This defect of the filler 6 does not occur only in the configuration of the corrugated thin plate, and the same performance degradation was observed in other aspects, for example, in a lattice-shaped filler.

[0006] The formation and growth of this algae is carried out by photosynthesis which requires light (sunlight etc.) and absorbs CO2 and emits O2 at the same time, since the algae itself is plant-based. Is sufficient, the growth is remarkable, especially in a cold water tower of a desulfurization facility containing a large amount of carbon dioxide in direct contact with the combustion exhaust gas.

The present inventor has focused on a Cl-based algicide which is generally effective in use in a cooling water tower using industrial water in order to prevent the generation of the above-mentioned algae. Tried to generate and remove algae, but the cooling water of desulfurization equipment containing a large amount of carbon dioxide gas contained:
Even if a considerable amount of Cl-based algicide was used, there was no effect.

[0008]

Therefore, the present inventor has further studied the above-mentioned means for preventing the generation of algae. Despite the fact that there is no such thing, we found that it occurred a lot on the downstream side, and based on this, we examined the death of algae. As a result, when it came into contact with hot water (40-60 ° C), Was found to be difficult to maintain. Based on this finding, the present inventor tried to temporarily interrupt the ventilation of the cooling water tower and allow high-temperature water to pass through the filler as it was. Was found to be maintained, and the present invention was completed.

As the cooling device in this case, in addition to the device for circulating the cooling water, for example, a cooling device for cooling high-temperature water containing carbon dioxide gas and discharging the same without reusing it can be applied. Further, in this cooling device, there is a case where the cooling function may be deteriorated due to the temporary interruption of the ventilation, but in such a case, the cooling water tower is constituted by a plurality of cooling chambers each having a filler. By arranging the cooling chambers in parallel with the flow path of the hot water (cooling water) and sequentially interrupting the ventilation of the respective cooling chambers, the other cooling chambers maintain the cooling function and the cooling capacity is reduced. It does not drop significantly.

The cooling chamber in this case includes a case where the cooling chamber is constituted by a plurality of independent casings, in addition to the method of dividing one casing into a plurality of cooling chambers by partition walls. Adopting a method in which the inside of one casing is divided by a partition is advantageous in that the piping of the casing and the circulation path can be labor-saving. The number of the plurality of cooling chambers is not limited as long as the number is two or more.

Here, as the cooling water tower, as shown in FIG. 2 (a), a natural ventilation type which sucks air from below the cooling water tower and secures a stable flow velocity by a chimney action, b) As in (c) and (d), there is a forced ventilation type using a fan to suck the atmosphere, and the like, but the present invention can be applied to any of these types of cooling water towers.

In order to temporarily interrupt the ventilation to the cooling water tower, for example, in the case of a natural ventilation type, an opening / closing damper may be installed at the ventilation opening, and when the ventilation is interrupted, the damper may be closed. In the case of forced ventilation using a fan (blower), the fan may be forcibly interrupted or operated in combination with a damper. In this case, the opening / closing operation of the damper or the driving / suspending operation of the fan may be either manual or automatic, and even in the case of automatic operation, not only automatic control by a timer, but also various sensors, for example,
The control may be performed by a signal from a weight sensor that detects a change in the weight of the filler. However, the control by the timer has advantages that it is safer and more reliable than the manual operation, and the circuit configuration is simpler than the control by the weight sensor.

As the ventilation interruption period, various periods such as every day, every other day, every week, etc. can be adopted, but it is more efficient to carry out every day. The ventilation interruption time is optimally about 15 to 20 minutes in order to achieve the algae killing effect, but the time is not particularly limited. Further, in the case where the ventilation of the plurality of cooling chambers is sequentially interrupted, the control method is not limited, such as interrupting the cooling chambers at intervals other than the method of continuously interrupting the ventilation.

Such cooling water containing carbon dioxide can be applied to equipment other than the circulating cooling apparatus in the desulfurization equipment for flue gas, and is applied, for example, to equipment for other chemical processes in which carbon dioxide is easily generated. You may. Of course,
If applied to a cooling device that cools high-temperature water from a gas-liquid contact tower in a flue gas desulfurization facility, it greatly contributes to prevention of algae generation in a filler of a cooling water tower.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of an exhaust gas desulfurization facility. In the present embodiment, the same reference numerals are given to the same functional members as the respective constituent members of the conventional flue gas desulfurization equipment shown in FIG.

In this flue gas desulfurization facility, the flue gas discharged from the combustion boiler 1 is removed through a wet absorption tower 2 by absorbing and neutralizing harmful acidic gases such as SO2 or HCl in an alkaline circulation path 10 and then removing the same. Since the exhaust gas contains a large amount of water, it is cooled with cooling water to lower the temperature of the exhaust gas while passing through the filler 11 of the gas-liquid contact tower 3 for the purpose of dehumidifying the gas. It is discharged from the upper part 12 of the liquid contact tower 3.

The gas-liquid contact tower 3 has a packing material 11 inside the tower.
A cooling device 17 having a circulation channel 16 for spraying cooling water from the cooling water tower 13 from above the filler 11 and recovering the cooling water from the water tank 14 below the filler 11 to the cooling water tower 13 by the pump 15 is provided. Is provided.

In the cooling water tower 13, high-temperature cooling water (warm water) is sprinkled and dropped from above the filler, and is brought into countercurrent contact with the air sucked from the air suction port 18 with a louver around the lower part of the tower to cool the tower. It is to be dropped into the water tank 19 below the filler and returned to the gas-liquid contact tower 3 by the pump 20 for reuse. On the other hand, the air that has taken heat by contacting the cooling water in the cooling water tower 13 is released into the atmosphere by a fan.

The cooling water tower 13 in the present embodiment is divided into three cooling chambers 22, 23,
24. In each of the cooling chambers, there are disposed plastic fillers 25a, 25b, and 25c in which a number of corrugated thin plates having a vertical plate surface are arranged, and fans 26a, 26b, and 26c are provided above the respective chambers. Is arranged. In addition, the lower part of each chamber is opened and the common water tank 19 is opened.
Are arranged, and the filler 25a,
Pipes 27a, 27b, 27c for cooling water (warm water) sprinkled from above 25b, 25c are arranged in parallel in the circulation path 16.

In the cooling water tower 13, once a day, 15 to 2
About 0 minute, the fans 26a of each of the cooling chambers 22, 23, 24,
Timer control is performed so that the driving of 26b and 26c is interrupted. Therefore, the timer 29 includes a cycle timer 29a for counting a drive stop cycle and an interruption time timer 29b for counting an interruption time.

By the operation of this timer, each cooling chamber 2
The driving of the fans 26a, 26b, 26c of 2, 23, 24 is stopped once a day at intervals, for example,
When the fan 26a of the first cooling chamber 22 stops, in the cooling chamber 22, the high-temperature cooling water passes through the filler 25a without being cooled, and a small part of the algae that is being generated in the filler 25a Can be burned to prevent the occurrence of algae. When the driving of the fan of the first cooling chamber 22 is restarted, the driving of the fans of the second cooling chamber 23 and the third cooling chamber 24 is sequentially stopped to kill the algae.

In this embodiment, the cooling chambers 22 and 2
3 and 24 are shown in a form divided into three by the partition 21,
However, the present invention is not limited to this, and the cooling chambers 22, 23, and 24 may be configured as independent towers, that is, a configuration in which a plurality of cooling water towers are arranged in parallel. In this case, any of the configurations of FIGS. 2A to 2D can be adopted as the configuration of each cooling tower.

FIG. 2 (a) shows a natural draft cooling water tower which sucks the atmosphere from below the tower and secures a stable flow velocity by the action of a chimney, and has a filler 31 inside and a cooling water sprinkling pipe above it. 32 are arranged. An opening / closing damper 30 is disposed at the lower suction port 18 of the tower, and when ventilation is temporarily interrupted, the damper 30 may be closed. FIG. 2B shows a forced draft cooling water tower in which the air is pushed in from the lower side of the tower by a fan 33 and water is sprayed from the upper part of the tower to cool the cooling water. 33 may be stopped. FIG. 2 (c) shows a draft ventilation cooling water tower similar to the present embodiment shown in FIG. FIG. 2 (d) shows a cross flow cooling water tower which circulates the air in a horizontal direction orthogonal to the downflow direction of the water sprinkling, and the air is sucked from the side and discharged from the opposite side.

[0024]

As is apparent from the above description, according to the present invention, in a cooling water tower that cools hot water containing carbon dioxide gas by bringing it into ventilation contact with the atmosphere, the ventilation is temporarily interrupted to cool the hot water. In this case, the algae attached to the filler in the cooling water tower can be killed, and the performance of the cooling water tower can be maintained.

The cooling water tower is composed of a plurality of cooling chambers each provided with a filler, and the cooling chambers are arranged in parallel in the flow path of the hot water so that the ventilation of each cooling chamber is interrupted sequentially. If this is the case, the other cooling chambers can maintain the cooling function and suppress a decrease in cooling capacity.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an exhaust gas desulfurization facility showing an embodiment of the present invention.

FIG. 2 shows various forms of a cooling water tower, and FIG.
Shows a natural ventilation type, (b) shows a pushing ventilation type, (c) shows a suction ventilation type, and (d) shows a cross flow type.

FIG. 3 is an overall configuration diagram of a conventional exhaust gas desulfurization facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler 13 Cold water tower 17 Cooling device 18 Air suction port 19 Water tank 21 Partition wall 22, 23, 24 Cooling chamber 25a, 25b, 25c Filling material 26a, 26b, 26c Fan 27a, 27b, 27c Piping

Claims (5)

[Claims] 1. A cooling device provided with a cooling water tower for cooling hot water containing carbon dioxide gas in a filler by bringing the hot water into air into contact with the atmosphere, whereby the ventilation in the cooling water tower is temporarily interrupted, and A cooling device configured to kill algae generated by attaching to the filler. 2. A cooling device having a cooling water tower for cooling hot water containing carbon dioxide gas in a filler by bringing the hot water into air into contact with the atmosphere, wherein the cooling water tower comprises a plurality of cooling chambers each having a filler. The cooling chambers are arranged in parallel in the flow path of the hot water, and in each of the cooling chambers, means for temporarily interrupting ventilation and killing algae attached to the filler by flowing hot water are provided, A cooling device wherein the plurality of cooling chambers are sequentially interrupted by each of the ventilation interrupting means. 3. A cooling water tower that cools a cooling water containing carbon dioxide gas that is brought into direct contact with combustion exhaust gas in a gas-liquid contact tower to bring it into ventilation contact with the atmosphere, and a cooling water that is cooled by the cooling water tower. And a cooling water circulation flow path for supplying the cooling water circulation tower again to the gas-liquid contact tower, wherein the cooling water tower has a plurality of cooling chambers each provided with a filler material arranged in parallel in the circulation path. A means for temporarily stopping the ventilation and killing the algae attached to the filler by the flowing high-temperature cooling water, and the plurality of cooling chambers are sequentially interrupted by the respective ventilation interruption means. Cooling system adapted to. 4. The cooling water cooling device according to claim 2, wherein said ventilation interrupting means is operated by a timer at a predetermined cycle for a predetermined time. 5. The cooling water cooling device according to claim 2, wherein the ventilation interrupting means interrupts the driving of an air suction fan provided in each of the cooling chambers.