KR102020501B1 - Cooling Tower of air separation plant for ironworks and Driving Method thereof - Google Patents

Abstract

Disclosed are a cooling tower of an ironworks air separation plant and an operating method using the same. Cooling tower of the steelworks air separation facility according to an embodiment of the present invention is a tower housing in which high-temperature cooling water splashes; Cooling water supply line for supplying a high temperature cooling water to the top of the tower housing; A heat exchange part into which outside air for heat exchange with high-temperature cooling water provided inside the tower housing is introduced; And a discharge line provided at a lower portion of the tower housing for discharging the coolant cooled by heat exchange, wherein the heat exchange unit includes a louver provided to allow external air to flow into the tower housing, and a storage tank in which liquid nitrogen is stored as a heat exchange medium. And an atmospheric vaporizer provided at the outside of the louver to lower the temperature of the atmosphere before passing through the louver while driving the atmospheric vaporizer in the summer at high atmospheric temperature, thereby effectively cooling the high temperature cooling water.

Description

Cooling Tower of Air Separation Plant and Operation Method Using It {Cooling Tower of air separation plant for ironworks and Driving Method}

The present invention relates to an air separation facility of a steel mill, and more particularly, to an air separation facility for separating oxygen, nitrogen, and argon contained in air by a difference in boiling point.

In general, steel mills operate an air separation system that separates oxygen, nitrogen, and argon contained in the air by a difference in boiling point by lowering the temperature while inhaling, compressing, and expanding the air in the atmosphere.

Specifically, the air separation unit removes foreign substances from the air in the air by using an air filter, and the air from which the foreign substances have been removed is supplied to the water washing cooling tower in a compressed state. The air provided to the flush cooling tower is cooled by the injection of the cooling water provided from the cooling tower, and the fine dust which is not completely removed by the air filter is removed together. The clean cooling air passing through the flush cooling tower is sent to the adsorber connected to the outlet of the flush cooling tower to remove the moisture and carbon dioxide contained in the air and then supply it to the expansion turbine. The air supplied to the expansion turbine is adiabaticly expanded and sent to the rectification tower to produce liquid gas (oxygen, nitrogen, argon) separated by boiling point.

As described above, the cooling tower is a heat exchanger that directly contacts and cools the outdoor air in order to reuse the coolant, and is widely used to supply high quality industrial water in large quantities in steel mills and industrial facilities that require a large amount of cooling water. Used.

The cooling tower basically sprays the cooling water evenly through a plurality of nozzles at the top of the tower to freely fall to the bottom, and the atmospheric air flowing from the outside is raised from the bottom to the top. That is, the free-falling cooling water is partially evaporated while contacting the rising atmospheric air, and at this time, the temperature of the cooling water decreases while depriving heat required for evaporation.

By the way, the compressor can be cooled sufficiently in the cooling tower during the low temperature of the air temperature, but the compressor is not overwhelming. However, during the high air temperature such as summer, the cooling water temperature is not sufficiently cooled. Because it is sent, a lot of power consumption occurs. In particular, in the air compressor, when the suction temperature of the compressor is increased due to the increase of the air temperature in the summer atmosphere, the air compressor is increased in volume, thereby increasing the load of the air compressor and increasing the power ratio. As a result, power loss and gas production can be problematic because weight loss must be achieved without normal compressor performance.

Korea Patent Registration No. 10-0834903 (2008.05.28)

According to an embodiment of the present invention to provide a cooling tower of a steelworks air separation facility and an operating method using the same, which can improve the efficiency of the facility through power saving by supplying the air sufficiently cooled in the summer.

According to an aspect of the present invention, a tower housing in which hot coolant is scattered; Cooling water supply line for supplying a high temperature cooling water to the top of the tower housing; A heat exchange part into which outside air for heat exchange with high-temperature cooling water provided inside the tower housing is introduced; And a discharge line provided at a lower portion of the tower housing for discharging the coolant cooled by heat exchange, wherein the heat exchange unit includes a louver provided to allow external air to flow into the tower housing, and a storage tank in which liquid nitrogen is stored as a heat exchange medium. Cooling tower of the steelworks air separation equipment comprising a; and an air vaporizer provided on the outside of the louver to lower the temperature of the atmosphere before passing through the louver while vaporizing.

In addition, the tower housing; a reservoir for storing the cooling water cooled in the lower portion; and the louver may be provided to be inclined toward the reservoir.

The heat exchange part may include a first vaporization line connected to the atmospheric vaporizer and a second vaporization line not connected to the atmospheric vaporizer and having a second vaporizer, wherein the first vaporization line and the second vaporization line have an external temperature. It can be selectively operated according to.

In addition, the first vaporization line and the second vaporization line includes a discharge line for discharging the vaporized liquid nitrogen in common, the first vaporization line to prevent the back flow of the vaporized liquid nitrogen when the second vaporization line is driven It may further include a check valve for.

According to another aspect of the present invention, in the cooling tower control method of a steelworks air separation facility for cooling the high-temperature cooling water by heat exchange with the outside air cooled by the vaporization of the heat exchange medium, the cooling tower has a first vaporizer having a first vaporizer And a second vaporization line having a second vaporizer, wherein the first vaporizer is provided adjacent to the tower housing of the cooling tower and is selectively operated in a summertime when the outside temperature is high. This may be provided.

In addition, the first vaporizer may use an atmospheric vaporizer.

The cooling tower of the steelworks air separation facility according to the embodiment of the present invention can effectively cool the high temperature cooling water even in a high temperature environment such as summer by lowering the temperature of the air introduced for heat exchange into the cooling tower using vaporization of liquid nitrogen. .

In addition, the operating method using the cooling tower of the steelworks air separation facility according to an embodiment of the present invention, the first vaporization line having an atmospheric vaporizer is provided adjacent to the tower housing of the cooling tower, and the second vaporizer is provided far from the cooling tower Including a second vaporization line having a high outside air temperature in the summer season by using the first vaporization line, and when the outside air temperature is low can be effectively utilized the liquid nitrogen vaporized by using a second vaporization line.

FIG. 1 schematically illustrates an air separation facility of a steel mill including a cooling tower according to an exemplary embodiment of the present invention.
2 is a view showing a cooling tower of the air separation facility according to an embodiment of the present invention.
3 is a view illustrating a heat exchanger including a first vaporization line and a second vaporization line provided in a cooling tower of an air separation apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as an example to sufficiently convey the spirit of the present invention to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. Parts not related to the description are omitted in the drawings in order to clearly describe the present invention, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 schematically illustrates an air separation facility of a steel mill according to an embodiment of the present invention.

Referring to the drawings, the air separation facility 10 of a steel mill according to an embodiment of the present invention compresses the air in the air from which the foreign matter is removed from the air filter 20 in the compressor 30, the compressed in the compressor 30 Air is a facility that separates and produces liquid gas (oxygen, nitrogen, argon) by boiling point due to passing through the water cooling tower 40, the adsorber 50, the expansion turbine 60 and the rectification tower 70.

That is, the air in the atmosphere is first removed foreign matter by the air filter 20, the air from which the foreign matter is removed is supplied to the compressor 30 is compressed to 5 ~ 6Kg / Cm2 is provided to the flush cooling tower 40.

The air provided to the flush cooling tower 40 is cooled by the injection of the cooling water provided from the cooling tower 100 and the fine dust that is not completely removed by the air filter 20 is removed together.

The clean cooling air passing through the flush cooling tower 40 is sent to the adsorber 50 connected to the outlet of the flush cooling tower 40 to remove the moisture and carbon dioxide contained in the air and then provide the expansion turbine 60.

The air supplied to the expansion turbine 60 is adiabaticly expanded and then sent to the rectification tower 70 to produce liquid gas (oxygen, nitrogen, argon) separated by boiling point.

2 is a view showing a cooling tower of an ironworks air separation facility according to an embodiment of the present invention.

Referring to the drawings, the cooling tower 100 according to the present embodiment is a tower housing 110 having a predetermined space, a supply line 120 for supplying a high temperature cooling water to the top of the tower housing 110, and a high temperature The filler 130 for uniformly dispersing and cooling the cooling water in the tower housing, the heat exchanger 140 for cooling the high temperature cooling water passing through the filler 130 by using heat exchange, and the cooling water cooled by the heat exchanger. A discharge line 160 for discharging to the outside of the housing 110 is included.

The tower housing 110 cools the high temperature coolant introduced into the heat exchanger by contacting with the cool air to perform heat exchange, and the cooled coolant can be stored in a predetermined space.

To this end, a suction fan 112 is provided at the upper portion of the tower housing 110 to allow external air for cooling to flow into the interior of the tower housing 110, and before discharging the coolant cooled by heat exchange to the outside. A reservoir 114 is provided for storage.

A space for heat exchange is provided between the reservoir 114 and the cooling water supply line 120. The heat exchange space is provided with a plurality of louvers 116 so that cool external air required to cool the hot cooling water may be introduced into the tower housing 110.

The louver 116 is a plurality of panels provided to be inclined downward from the outside to the inside of the side wall of the tower housing 110, and the inclination may be provided at about 45 degrees to face the upper surface of the reservoir 114. Here, the present invention exemplifies the installation angle of the louver 45 degrees, the present invention is not limited to this may be provided to adjust the inclination.

Cooling water supply line 120 is to be used in a separate facility for supplying and spraying the cooling water is raised to a high temperature to the inside of the tower housing 110, the opening and closing valve 122 is provided at the inlet side, the tower housing Dispersion pipe 124 extending to the upper region inside the 110 to evenly distribute the coolant, and a plurality of coolant injection nozzles 126 for spraying coolant to the lower side of the coolant dispersion pipe 124, that is, the cooler 130. ).

The filler 130 is for evenly dispersing the coolant injected from the coolant injection nozzle 126, and a plurality of partitions may be provided in a multi-layered form to disperse the coolant from falling by its own weight. Here, the filler 130 according to the present embodiment is not limited to a specific shape and may be implemented by changing to various structures that can evenly distribute the falling coolant.

The heat exchanger 140 is for lowering the temperature of the coolant through heat exchange by contacting the cool external air with the high temperature coolant uniformly dispersed inside the tower housing 110 through the filler 130.

To this end, the heat exchanger 140 includes a plurality of first vaporizers 142 adjacent to the tower housing 110, a first vaporization line 144 connecting the plurality of first vaporizers 142, and a first vaporization. A first storage tank 146 for supplying heat exchange medium to the first vaporizer 142 via line 144.

The heat exchanger 140 according to the present embodiment uses liquid nitrogen at −196 ° C. as the heat exchange medium. The liquid nitrogen vaporizes about 646 times as much as 1 liter of gas at 0 degreeC, 682 times as much as 15 degreeC, and about 729 times as much gas as 35 degreeC. That is, since liquid nitrogen is easy to vaporize even at atmospheric temperature and is very large in volume expansion when it is used by vaporizing, liquid nitrogen can be vaporized very efficiently by using liquid nitrogen in hot weather (30 ° C. or more).

The first vaporizer 142 uses a method of vaporizing by heat, and in particular, an atmospheric vaporizer may be used to effectively use the hot summer. A plurality of first vaporizers 142 are distributed around the first vaporization line 144, and spaced apart from each other by a predetermined distance to the louver 116 outside the space where the heat exchange of the tower housing 110 is performed. As shown in FIGS. 2 and 3, the plurality of first vaporizers 142 are installed in close proximity to the louver 16 of the tower housing 110 and flow into the tower housing 110 through the louver 116. The heat of all the atmosphere can be taken away and can be cooled down. Furthermore, by adsorbing moisture in the atmosphere, only the cold and dried atmosphere can be supplied to the tower housing 110.

The first storage tank 146 is connected to the first vaporization line 144 to supply liquid nitrogen to the first vaporizer 142. The booster vaporizer 148 may be connected to the first storage tank 146 so that the pressure and the gas amount may be adjusted according to the use place.

The cooling water discharge line 160 is provided to discharge the cooled cooling water to one side of the reservoir 114 to the outside, and may include an on / off valve 162.

Meanwhile, according to the present embodiment, the heat exchanger 140 may further include a second heat exchanger 150 that vaporizes without passing through the tower housing 110. For convenience of description, the heat exchanger 140 may be referred to as a first heat exchanger hereinafter.

That is, as shown in FIG. 3, the second heat exchange part 150 includes a second storage tank 151 in which liquid nitrogen, which is a heat exchange medium, is stored, and a pump for transferring liquid nitrogen in the second storage tank 151. 152, a second vaporizer 153 for vaporizing liquid nitrogen, and a second vaporization line 154 through which liquid nitrogen moves.

The second storage tank 151 stores liquid nitrogen like the first storage tank 146.

The pump 152 transfers the liquid nitrogen of the second storage tank 151 along the second vaporization line 154, and also supplies liquid nitrogen through the first vaporization line 144 of the heat exchanger 140. It may include a branch pipe (not shown). For example, when the liquid nitrogen of the first storage tank 146 is insufficient, the pump 152 may be connected to the first vaporization line 144 to transfer the liquid nitrogen.

The second vaporizer 153 may be in various forms. Although the second vaporizer 153 may use an atmospheric vaporizer such as the first vaporizer, a hot water vaporizer or a steam vaporizer may be employed so that the second vaporizer 153 may also be used in winter.

In addition, an opening / closing valve 155 may be provided between the second vaporizer 153 and the pump 152. The on-off valve 155 may employ an electromagnetic valve that is electrically operated. When the open / close valve 155 is closed, the liquid nitrogen of the second storage tank 151 is supplied to the first vaporization line 144, and in the open state, the liquid nitrogen is supplied to the second vaporization line 154.

In the drawing, reference numeral 149, which is not described, is used to vaporize the second heat exchanger 150 in the first heat exchanger 140 and the second heat exchanger 150 having a discharge line for discharging vaporized liquid nitrogen in common. It is a check valve to prevent the flow of liquid nitrogen back to the first vaporization line (144) side. The vaporized liquid nitrogen discharged through the first vaporization line 144 and the second vaporization line 154 may be supplied to other facilities of the steelworks using the same, although not shown.

Then, the cooling tower operation of the steelworks air separation facility according to the present embodiment will be described.

Cooling tower 100 may be selectively operated according to the season, such as the summer season when the atmospheric temperature is greater than 30 ℃ large, and other winter season and low season when the atmospheric temperature is low. In addition, although not specifically described in the present embodiment, a control panel for effectively driving the cooling tower 100 may be provided.

First, when the high temperature coolant is supplied to the inside of the tower housing 110 through the coolant supply line 120, the high temperature coolant is scattered to the filler 130 through the coolant dispersion pipe 124 and the coolant injection nozzle 126. The filler 130 uniformly distributes the hot cooling water that is scattered in the heat exchange space of the tower housing 110. The high temperature coolant falling from the heat exchange space is cooled while contacting the outside air introduced through the louver 116, and the cooled coolant is collected in the reservoir 114 of the tower housing 110 and discharged if necessary. Can be discharged to outside.

In summer, since the outside air temperature introduced through the louver 116 into the tower housing 110 is high, heat exchange of the high temperature cooling water is not easy. In this case, the control panel (not shown) presses the liquid nitrogen to the first vaporizer 142 using the booster vaporizer 148 of the first storage tank 146, and the first vaporizer 142 vaporizes the liquid nitrogen while externally vaporizing the liquid nitrogen. Cool the air coolly. At this time, the first vaporizer 142 may adsorb moisture from the outside air, and the cold air in the dry state flows into the tower housing 110 and comes into contact with the cooling water of the reservoir 114 and with the high temperature cooling water falling while rising. The latent heat of vaporization in contact effectively reduces the temperature of the cooling water. The vaporized liquid nitrogen can be supplied to other plants of the steelworks as needed.

On the other hand, the first vaporization line 144 of the heat exchanger 140 is not used in the winter, such as the temperature of the outside air is relatively low. Therefore, when the liquid nitrogen vaporized in the external equipment is required, it can be supplied through the second vaporization line (154).

10. Air separation equipment 20. Air filter
30. Compressor 40. Flush cooling tower
50. Adsorber 60. Expansion turbine
70. Rectification tower 100. Cooling tower
110..Tower housing 114..Reservoir
116 Louver 120 Coolant Supply Line
130. Filler 140 .. (1) Heat exchanger
142 .. 1st vaporizer (atmospheric vaporizer) 144 .. 1st vaporizer line
146 .. 1st storage tank 150. 2nd heat exchanger
152 pumps 153 second carburetor
154 .. Second vaporization line 160. Coolant discharge line

Claims (6)

A tower housing in which hot coolant is scattered;
Cooling water supply line for supplying a high temperature cooling water to the top of the tower housing;
A heat exchanger having a louver into which external air for heat exchange with high temperature cooling water scattered provided in the tower housing is introduced;
A discharge line provided at a lower portion of the tower housing for discharging cooling water cooled by heat exchange;
A plurality of first vaporizers provided adjacent to the outside of the tower housing and disposed to face the louvers of the heat exchange unit; And
And a first storage tank for supplying a heat exchange medium to the heat exchange unit through a first vaporization line connecting the plurality of first vaporizers.
The first vaporizer uses an air vaporizer to vaporize by heat, the first storage tank is a cooling tower of a steel mill air separation facility in which the liquid nitrogen is stored as a heat exchange medium. The method of claim 1,
The tower housing includes a reservoir for storing cooled cooling water in a lower portion thereof.
The louver is a cooling tower of the steelworks air separation facility is provided to be inclined toward the reservoir. The method of claim 1,
Further comprising a second heat exchanger remotely provided to the outside of the tower housing,
A second storage tank in which liquid nitrogen for supplying to the second heat exchange unit is stored;
A second vaporization line and a second vaporizer for vaporizing liquid nitrogen transferred from the second storage tank;
A pump for selectively supplying liquid nitrogen to the first vaporization line and the second vaporization line including an on / off valve and a branch pipe,
The first vaporization line and the second vaporization line commonly includes a discharge line for discharging the vaporized liquid nitrogen,
The first vaporization line further comprises a check valve for preventing backflow of liquid nitrogen vaporized when the second vaporization line is driven. The method of claim 3,
The first vaporization line is used in summer,
The second vaporization line is a cooling tower of the air separation facility of the steelworks used in winter. delete delete

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