KR20020023295A - System for deaerating - Google Patents

Abstract

Disclosed is a degassing system that saves energy and significantly prevents corrosion of equipment. This degassing system consists of a degassing part, a storage part, and a heat recovery part, and the hot steam which drives the turbine to the lower part of the degassing tank 70 is supplied through the supply line 31, and the water supply from the upper part of the degassing tank 70 Condensate + make-up water) is passed through the spray pipe 71 to the upper tray 72, and the feed water sequentially falls through the trays and crosses the hot steam rising from the bottom to prevent the heating. do. The water supplied from the tray is stored in the reservoir 80. Dissolved gases (non-condensable gases: oxygen, carbon dioxide, etc.) that are released as the feedwater is sprinkled in the degassing zone and heated by the steam are moved to the upper part of the degassing chamber by the pressure of the incoming steam, Together with the supply pipe 73 is supplied to the heat recovery tank (90).

The water supplied to the inlet side supply pipe 61 of the water supply at the bottom of the heat recovery tank 90 is passed through the outlet side water supply pipe 62 by the internal water supply pipe 91 through a predetermined pattern to the degassing tank 70. Supplied. Steam and non-condensed gas from the degassing tank 70 gives a high temperature heat (latent heat) to the feed water passing through the internal water supply pipe 91, the steam is condensed at the saturation temperature of the operating pressure of the heat recovery unit, the non-condensed gas It exits to the vent hole 92 and is discharged to the outside through the vent pipe 93 to atmospheric pressure.

The condensed water condensed at the saturation temperature of the heat recovery unit operating pressure is stored up to the height of the discharge pipe 94 where the heat (sensible heat) is deprived of the water supplied to the submerged coil and the condensed water is cooled.

Vent holes 92 are formed on the outer circumferential surface of the vent pipe 93 so that the non-condensable gas is discharged. The discharge pipe 94 has a diameter smaller than that of the vent pipe 93 so that the condensed water can be smoothly removed from the vent pipe 93. Allow the gap to be spaced apart.

One end of the discharge pipe (94) protrudes outward and is connected to the discharge pipe supplied to the reservoir (80), and the other end is raised to a position lower than the vent hole so that this height becomes the level of condensate. Quantity is decided.)

This degassing system removes dissolved gases in power plant boilers and water circulation systems to prevent metal corrosion and improve the performance of equipment. In addition, it is possible to save energy by recovering high temperature steam discharged together with the dissolved gas from the water supply tank and preheating the water supply to the water supply tank.

Description

Degassing System {System for deaerating}

The present invention relates to a degassing system, and more particularly, to remove the dissolved gas in the water in order to prevent corrosion of the metal material due to the dissolved gas in the supply water, such as industrial and power plant boilers, cooling facilities. It relates to one degassing system.

Generally, water exposed to the atmosphere is dissolved in nitrogen, oxygen, carbon dioxide, and ammonia. Nitrogen is about twice as dissolved as oxygen, and carbon dioxide and ammonia are slightly dissolved. Oxygen in the dissolved gas depends on pressure and temperature, but contains about 8 to 10 ppm of dissolved oxygen at normal pressure and room temperature. For example, the dissolved oxygen is 11.43 ppm at the water temperature of 10 ° C and 1.43 ppm at the water temperature of 99 ° C.

The gases that corrode boilers or water systems in dissolved gases are oxygen and carbon dioxide. Oxygen is about 5 to 10 times more corrosive than carbon dioxide, and more corrosive when carbon dioxide coexists. Therefore, oxygen and carbon dioxide not only shorten the life of the facility by corroding the metal, but also when the corrosion product is attached to the heat transfer surface, it lowers the thermal efficiency of the process and causes an increase in the pump power ratio due to an increase in the differential pressure. If too much corrosion products are attached to the high temperature heat transfer surface, heat transfer may be reduced and cause rupture accidents.

If the dissolved oxygen and dissolved carbon dioxide is included in the water used for the boiler, etc., the metal material such as the facility is corroded, thereby removing the dissolved oxygen and dissolved carbon dioxide through a deaerator. In particular, corrosion increases rapidly with increasing pressure.

These deaerators are used everywhere, including power plants, using various steams, such as incineration plants, boilers, and the like.

1 exemplarily shows one of the installations in which the degasser is installed. As shown, steam is generated by the operation of the boiler 1, and the generated high pressure / high temperature steam operates the turbine 2 and the generator 3. The high temperature / high pressure steam which drives the turbine 2 is supplied to the high pressure water supply heater 6 via the plurality of low pressure water supply heaters 5 via the condenser 4 and circulated back to the boiler 1. At this time, the deaerator 10 is installed between the low pressure water heater 5 and the high pressure water heater 6.

The degasser 10 serves to remove dissolved oxygen and carbon dioxide in the water. Since oxygen in the water causes corrosion, it is preferable to remove the dissolved oxygen until it becomes 0.01 to 0.007 ppm (0.007 to 0.005 cc / l).

There are various methods of degassing such as vacuum decompression or reducing agent treatment. Among them, in the heating degassing method, the solubility of gas in water is reduced in accordance with the Henry's Law using a principle that is proportional to the partial pressure of the component in the gas phase, thereby reducing the gas partial pressure. Dissolved gases can be removed from the In addition, the solubility of the gas decreases with increasing temperature under the influence of temperature. Using this principle, the feedwater is heated with steam in a heated degasser and mixed with high-pressure steam to reduce dissolved non-condensable gas partial pressure in water.

Referring to FIG. 2, which shows a conventional heating degasser, it consists of a storage tank 8 and a degassing tank 7 and feeds via a low pressure water heater 5 at the top of the degassing tank 7 (line A). Is supplied and hot steam is supplied from the turbine 2 (line B). At this time, the oxygen remaining in the water is removed at a high temperature and is released to the outside through the vent (7a).

However, the gas discharged through the upper vent (7a) of the degassing tank (7) in the conventional heating degassing as described above is not only dissolved gas such as oxygen, carbon dioxide, but also inevitably to the high temperature steam to generate energy loss. And the thermal efficiency of the boiler is falling.

The present invention has been made to solve the above problems, to provide a degassing system to improve the performance of the facility by preventing the occurrence of metal corrosion by removing the dissolved gas of the industrial and power plant boiler and water circulation system The purpose is.

It is another object of the present invention to provide a dissolved gas removal apparatus which inevitably improves efficiency by recovering high temperature steam discharged together with the dissolved gas and heats the water supply, and saves the water supply by resupplying the recovered condensate. have.

1 is a block diagram showing a conventional boiler equipment employing a conventional degasser;

Figure 2 is a schematic cross-sectional view showing the deaerator adopted in Figure 1,

3 is a block diagram showing a facility employing the apparatus of the present invention;

4 is a schematic cross-sectional view showing the present invention degassing system employed in FIG.

5 is a cross-sectional view showing another embodiment of the device of the present invention.

* Explanation of symbols for main parts of the drawings

20 boilers 30 turbines

40 ... generator 50 ... plural

60 ... Low pressure water heater 61,62.Inlet / outlet water supply piping

70.Degassing 72.Tray

71 ... spray pipe 80 ... storage

90.Heat recovery tank 91.Built-in water supply pipe

93 Vents 92 Vents

94.Exhaust pipe

The present invention to achieve the above object is to reduce the non-condensable gas partial pressure in the water by heating the water supplied through the water pipe to the degassing tank with steam and mixed with high-pressure steam through the vent through the non-condensable gas from the water In the degassing system to remove,

A heat recovery tank supplied with the dissolved gas and steam through a supply pipe connected to the vent;

A vent pipe having one end exposed to the outside of the heat recovery tank and the other end accommodated in the heat recovery tank, and having a vent hole formed at an outer circumferential surface of the heat recovery tank;

It has a diameter smaller than the vent pipe and its one end is coupled so as to be spaced apart from the inner peripheral surface of the vent pipe by a predetermined distance, the one end is located in a position lower than the vent hole and the other end is exposed to the outside of the heat recovery tank,

A built-in water supply pipe connected to the water supply pipe via a predetermined pattern in the heat recovery tank,

The water supply to the degassing tank is supplied through the internal water supply pipe in the heat recovery tank, and the dissolved gas in the heat recovery tank is exhausted through the vent hole.

The internal water supply pipe may be provided by winding a plurality of internal water supply pipes around the vent pipe in the heat recovery tank.

In addition, a storage tank for temporarily storing condensed water condensed in the degassing tank is provided,

Condensed water condensed in the heat recovery tank may be configured to be discharged through the discharge pipe is supplied to the reservoir.

On the other hand, the present invention to achieve the above object in the degassing system to drive the turbine with a high temperature / high pressure steam generated in the boiler, remove the dissolved gas from the condensed water condensed steam to drive the turbine,

A degassing tank having a plurality of trays supplied with high-temperature steam driving the turbine from a bottom part, supplied with the water supply from the top, and sequentially dropping the water supply;

A storage tank in which water supplied from the tray is stored;

A heat recovery tank supplied with steam and dissolved gas discharged to an upper portion of the degassing tank, and having a built-in water supply pipe of condensate supplied to the degassing tank via a predetermined pattern;

A vent pipe having one end exposed to the outside of the heat recovery tank and the other end accommodated in the heat recovery tank, and having a vent hole formed at an outer circumferential surface of the heat recovery tank;

One end of the vent pipe is smaller than the vent pipe and is spaced apart from the inner circumferential surface of the vent pipe by a predetermined distance, and one end thereof is positioned at a lower position than the vent hole, and the other end of the vent pipe is exposed to the outside of the heat recovery tank and connected to the storage tank. Characterized in that.

According to the above characteristics of the present invention, the degassing system of the present invention is capable of saving energy by preheating the hot water supplied to the degassing tank by heat recovery of the hot steam discharged together with the dissolved gas from the degassing tank, and the steam recovered in the heat recovery tank. Condensation and re-supply to the reservoir, and only the dissolved gas is discharged into the vent pipe to save water.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to Figure 3 employing a degassing system according to the present invention, which is a boiler 20 for generating a high temperature / high pressure steam, a turbine 30 and a generator 40 driven by the generated high temperature / high pressure steam and , A condenser 50 for condensing the steam driving the turbine 30, a low pressure water heater 60 for heating the condensed condensate, and the present invention system 70, 80, 90 for removing dissolved gas from the heated water supply. ) And a high pressure water heater (100).

Referring to FIGS. 3 and 4, the high temperature steam driving the turbine 30 from the bottom of the degassing tank 70 is supplied through the supply line 31, and the water supply is supplied from the upper part. A degassing part having a plurality of trays 72 which are sequentially dropped; A storage tank (80) in which water supplied from the tray (72) is stored; Steam and dissolved gas discharged to the upper portion of the degassing tank 70 is supplied through a supply pipe 73, the heat recovery tank 91 through the built-in water supply pipe 91 of the water supplied to the degassing tank 70 in a predetermined pattern ( A heat recovery portion having 90); A vent pipe (93) having one end exposed to the outside of the heat recovery tank (90) and the other end accommodated in the heat recovery tank (90) and having a vent hole (92) formed at an outer circumferential surface of the heat recovery tank (90); The vent pipe 93 has a diameter smaller than that of one end thereof so as to be spaced apart from the inner circumferential surface of the vent pipe 93 by a predetermined distance, and one end thereof is positioned at a position lower than the vent hole 92, and the other end is outside the heat recovery tank 90. It is provided with a; discharge pipe (94) connected to the reservoir (80).

In the above, the internal water supply pipe 91 is connected to the outlet side supply pipe 62, one end of which is connected to the degassing tank 70 at the outside of the heat recovery tank 90, the other end is connected to the low pressure water supply heater 60 and It is connected to the inlet side supply pipe 61 is connected.

The operation of the present invention degassing system is as follows. The water passing through the low pressure water heater (60) passes through the internal water supply pipe (91) in the heat recovery tank (90) through the inlet side water supply pipe (61) through a spray pipe (71; spray pipe) to the degassing tank (70). Injection is supplied. The water supplied by injection into the degassing tank 70 is dissolved in the non-condensed gas, oxygen (O2) and carbon dioxide (CO2), which are separated while mixing with the hot steam supplied to the degassing tank 70 through the supply line 31. Gas is discharged to the heat recovery tank 90 along with the remaining steam through the supply pipe (73).

The discharged dissolved gas and steam heat the built-in water supply pipe 91 wound in the form of a coil passing through with latent heat, thereby raising the temperature of the water supply to be supplied to the degassing tank 70.

On the other hand, the steam heat exchanged with the water supply is condensed to the condensation temperature of the operating pressure of the heat recovery unit is stored up to the height of the discharge pipe 94, where the heat (sensible heat) is supplied to the low temperature water supply supplied into the submerged water pipe coil in the stored condensate again After the condensate is cooled down, the condensate is cooled and discharged by overflowing the upper portion of the discharge pipe 94, and the non-condensing gas (O2, CO2) is collected in the upper space of the condensate stored in the heat recovery tank (90). At this time, since the molecular weight of the non-condensed gas is heavier than the molecular weight of the vapor, it is collected directly on the water surface and is discharged to the outside through the vent hole 92.

That is, while steam and non-condensable gas enter the upper portion of the heat recovery tank 90 and move downward, steam is condensed and only the non-condensable gas remains and is discharged into the vent hole 92 directly above the water surface.

Therefore, the vent hole 92 is located slightly above the condensate surface as shown in FIG. 4, and is also positioned higher than the upper end of the discharge pipe 94.

Meanwhile, referring to FIG. 5, which shows another embodiment of the present invention, it adopts a plurality of water supply pipes 95 so as to be suitable for a large-capacity facility so as to be wound together so as to pass through the heat bath 90. Other components are the same as described above, so detailed description thereof will be omitted.

It is needless to say that the present invention is not limited to the above embodiments and can be practiced with many modifications without departing from the spirit and scope of the present application.

The present invention removes dissolved gases in industrial and power plant boilers and water circulation systems to prevent the occurrence of corrosion of metal to improve the performance of the facility.

In addition, energy saving is possible by recovering the high temperature steam discharged together with the dissolved gas from the degassing tank and preheating the feed water supplied to the degassing tank.

In addition, the steam recovered in the heat recovery tank is condensed and re-supplied to the storage tank, and only the dissolved gas is discharged into the vent pipe to save water.

Claims (4)

In the degassing system to remove the non-condensable gas released from the water supply by venting the non-condensable gas partial pressure in the water by heating the water supplied through the feed pipe to the degassing tank with steam and mixed with high-pressure steam, A heat recovery tank through which the dissolved gas and the steam are supplied through a supply pipe connected to the vent; A vent pipe having one end exposed to the outside of the heat recovery tank and the other end accommodated in the heat recovery tank, and having a vent hole formed at an outer circumferential surface of the heat recovery tank; It has a diameter smaller than the vent pipe and its one end is coupled so as to be spaced apart from the inner peripheral surface of the vent pipe by a predetermined distance, the one end is located in a position lower than the vent hole and the other end is exposed to the outside of the heat recovery tank, A built-in water supply pipe connected to the water supply pipe via a predetermined pattern in the heat recovery tank, Dewatering system, characterized in that the water supplied to the degassing tank is supplied through the internal water supply pipe in the heat recovery tank, the dissolved gas in the heat recovery tank is exhausted through the vent hole. 2. The degassing system according to claim 1, wherein a plurality of the built-in water supply pipes are provided by winding around the vent pipe in the heat recovery tank together. The storage tank according to claim 1 or 2, wherein condensate condensed in the degassing tank is temporarily stored. The condensed water condensed in the heat recovery tank is discharged through the discharge pipe is characterized in that it is supplied to the reservoir. In the degassing system for driving the turbine with high-temperature / high pressure steam generated in the boiler, the dissolved gas is removed from the condensed water condensed steam to drive the turbine and re-supplied to the boiler, A degassing tank having a plurality of trays supplied with high-temperature steam driving the turbine from a bottom part, supplied with the water supply from the top, and sequentially dropping the water supply; A storage tank in which water supplied from the tray is stored; A heat recovery tank supplied with steam and dissolved gas discharged to an upper portion of the degassing tank, and having a built-in water supply pipe of condensate supplied to the degassing tank via a predetermined pattern; A vent pipe having one end exposed to the outside of the heat recovery tank and the other end accommodated in the heat recovery tank, and having a vent hole formed at an outer circumferential surface of the heat recovery tank; One end of the vent pipe is smaller than the vent pipe and is spaced apart from the inner circumferential surface of the vent pipe by a predetermined distance, and one end thereof is positioned at a lower position than the vent hole, and the other end of the vent pipe is exposed to the outside of the heat recovery tank and connected to the storage tank. Degassing system characterized in that.