KR102585185B1 - Thermal power plant denitrification facility urea vaporizer clogging early detection system - Google Patents

Abstract

The present invention relates to an early detection system for urea vaporizer blockage in a thermal power plant denitrification facility, which can detect blockage in the urea vaporizer early and promote stable power generation facility operation.
A feature of the present invention is a urea vaporizer (100) that mixes and discharges urea with combustion gas discharged from a gas turbine of a power plant, a urea supply unit (200) that supplies urea to the urea vaporizer (100), and a urea vaporizer ( A pressure gauge 300 installed in the urea vaporizer 100 to measure the pressure, an ammonia meter 400 installed in the urea vaporizer 100 to measure ammonia vaporized from urea, and a warning unit 500 to warn of a clogging phenomenon, It includes a control unit 600 that controls the warning unit 500 based on the measurements of the pressure gauge 300 and the ammonia meter 400.

Description

Early detection system for urea vaporizer clogging in thermal power plant denitrification facility {Thermal power plant denitrification facility urea vaporizer clogging early detection system}

The present invention relates to a SCR (Seletive Catalytic Reduction) urea denitrification equipment reducing agent vaporizer used in large-capacity thermal power boilers such as thermal power plants and industrial boilers. It can detect clogging of the urea vaporizer early and promote stable operation of power generation facilities. This is about an early detection system for blockage of the urea vaporizer of a thermal power plant denitrification facility.

In general, nitrogen oxides generated after combustion in thermal power plants exist in various types depending on the bonding state of nitrogen and oxygen. Most of what is generated by combustion of fuel is NO and NO2, and is generally referred to as nitrogen oxides (NOx).

Measures to reduce nitrogen oxides (NOx) generated during combustion include:

First, there is a pre-combustion treatment method that reduces fuel NOx by removing nitrogen oxides in fuel in advance. Second, there is a low NOx combustion technology as a method of reducing NOx during combustion by improving combustion equipment and improving and changing combustion methods. Third, there is low NOx combustion technology. , there is a technology that applies NOx reduction method to exhaust gas generated during combustion.

Among these NOx reduction methods, selective catalytic reduction (SCR), one of the post-combustion treatment methods, is widely used.

The selective catalytic reduction (SCR) process involves simultaneous contact between exhaust gas and a reducing agent in the catalyst layer under a temperature of 300~400℃, thereby converting NOx in the exhaust gas into nitrogen (N2) and water vapor (H2O) through a selective reaction with the reducing agent (NH ₃ ). It is a way to reduce it.

Reducing agents used include liquefied ammonia (purity 99.5%), ammonia water (mainly 25% ammonia solution), and urea solution (mainly 40% solution).

In the early days of thermal power plants, liquefied ammonia (99.5% purity) was mainly used as a reducing agent, but many safety issues arose, including risks to the human body and the environment, due to the use of toxic ammonia high-pressure gas.

Due to the toxic ammonia gas pressure of 3 to 5 kg/㎠ in the ammonia injection system, maintenance is difficult when storage tanks, pipes, and valves leak, and there is a risk of workers being directly exposed to harmful gas.

Therefore, there is currently a trend, especially in the metropolitan area, to change the denitrification reducing agent in power plants to urea, which is harmless to the human body and the environment.

Figure 1 is a diagram schematically showing the configuration of a selective denitrification facility using urea.

As shown in Figure 1, the SCR denitrification facility using urea in a combined cycle power plant blows out high temperature (360°C) combustion gas from the gas turbine outlet with a blower and vaporizes the urea solution (40%) in a vaporizer to produce ammonia. (NH3) is produced. The generated ammonia (NH3) is sent to the SCR (Selective Catalytic Reduction) catalyst layer in the boiler through the AIG (Ammonia Injection Grid) to remove NOx and then discharged through the chimney.

The evaporation and vaporization chemical reaction of urea (3H2N-CO-NH2) consists of primary and secondary thermal decomposition reactions.

However, the urea solution that fails to completely vaporize into NH3 through the first and second thermal decomposition reactions produces cyanuric acid, biuret, ammelide, etc., which attach to the wall of the vaporizer and cause clogging. Blockage due to carburetor blockage causes exhaust gas NOx environmental regulations to be exceeded, and NOx becomes a precursor to ultrafine dust and has a harmful effect on the human body, causing problems such as stopping power generation facilities and causing disruption in operation. there is.

The background technology of the present invention is published in Registered Patent Publication No. 10-1767365 (2017.08.05.), which was applied for and registered with the Korean Intellectual Property Office.

The problem to be solved by the present invention is to provide an early detection system for urea vaporizer blockage in a thermal power plant denitrification facility that can detect blockage in the urea vaporizer early and promote stable power generation facility operation.

The early detection system for blockage of the urea vaporizer of a thermal power plant denitrification facility according to an embodiment of the present invention includes a urea vaporizer 100 that mixes combustion gas discharged from a gas turbine of the power plant with urea and discharges urea, and a urea vaporizer 100. A urea supply unit 200 that supplies urea, a pressure gauge 300 installed in the urea vaporizer 100 to measure pressure, and an ammonia meter installed in the urea vaporizer 100 to measure the concentration of ammonia vaporized from urea ( 400, a warning unit 500 that warns of clogging, a control unit 600 that controls the warning unit 500 based on the measurement of the pressure gauge 300 and the ammonia meter 400, and a urea vaporizer ( It includes a vortex 700 installed in 100 and composed of a fan to promote vaporization of urea, and the urea vaporizer 100 has a combustion gas inlet 110 formed at the bottom through which combustion gas flows, and the combustion gas introduced therein is formed at the bottom. A combustion gas outlet 120 through which gas is discharged is formed at the top, and the combustion gas flowing in through the combustion gas inlet 110 is mixed with urea, and the vaporization space 130 guided to the combustion gas outlet 120 is formed to produce combustion gas. It is formed larger than the diameter of the inlet 110 and the combustion gas outlet 120, and a catalyst layer 140 is formed in the vaporization space 130. The catalyst layer 140 is composed of a SCR (Selective Catalytic Reduction) catalyst layer, and is meshed ( It is formed in the form of a mesh) and the high temperature combustion gas of 360℃ discharged from the gas turbine is supplied to the urea vaporizer 100, so the reaction temperature of the catalyst layer 140 is about 320~400℃ and the NOx removal efficiency is high, and the catalyst layer 140 has a high NOx removal efficiency. The lifespan of (140) is also extended, and the urea supply unit (200) has a nozzle (210) that sprays urea water mixed with urea into the inside of the urea vaporizer (100) and supplies urea in a set amount for a set time. It includes a pump 220 that supplies the amount, and the nozzles 210 are composed of a plurality and are installed symmetrically on both sides as they approach the combustion gas inlet 110 of the urea vaporizer 100. The pressure gauge 300 is composed of a plurality of nozzles 210. It is configured and installed at the combustion gas inlet 110 and combustion gas outlet 120 of the urea vaporizer 100, and the control unit 600 includes a pressure confirmation unit 610 that checks the current pressure of the pressure gauge 300, and an ammonia meter. An ammonia confirmation unit 620 that checks the current ammonia of (400), a standard setting unit 630 that sets the standard pressure and standard ammonia, compares the current ammonia to the standard ammonia to determine whether it matches, and compares the current ammonia to the standard pressure. A determination unit 640 that compares the pressures to determine whether they match, and a warning unit ( It includes a warning operation unit 650 that operates the warning operation unit 650, and a swing operation unit 660 that operates the swirler 700 when the judgment unit 640 determines that the current ammonia does not match the reference ammonia, The standard setting unit 630 sets the standard ammonia based on the amount of urea supplied by the pump 220 of the urea supply unit 200, and compares the pressures initially measured by the pressure gauges 300 to match each other. If so, the matched pressure is set as the reference pressure.

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The early detection system for clogging of the urea vaporizer of a denitrification facility in a thermal power plant according to an embodiment of the present invention has the advantage of promoting stable operation of power generation facilities by detecting the clogging of the urea vaporizer at an early stage.

In addition, there is the advantage of minimizing SCR equipment failure and power generation equipment stoppage due to clogging of the urea vaporizer and predicting SCR nitrogen oxide removal efficiency in advance.

In addition, there is an advantage in that installing a swirler in the urea vaporizer can generate sufficient heat and fluid mixing inside, thereby promoting the vaporization of urea and thus the production of ammonia.

Figure 1 is a diagram schematically showing the configuration of a selective denitrification facility using urea.
Figure 2 is a diagram showing an early detection system for clogging of the urea vaporizer of a thermal power plant denitrification facility according to an embodiment of the present invention.
Figure 3 is a block diagram schematically showing the configuration of the present invention.
Figure 4 is a block diagram showing the control unit of the present invention.

Hereinafter, with reference to the attached drawings, an early detection system for clogging of the urea vaporizer of a thermal power plant denitrification facility according to an embodiment of the present invention will be described in detail.

As shown in Figures 2 to 4, the present invention includes a urea vaporizer (100) that mixes and discharges urea with combustion gas discharged from a gas turbine of a power plant, and a urea supply unit that supplies urea to the urea vaporizer (100). (200), a pressure gauge (300) installed in the urea vaporizer (100) to measure pressure, and an ammonia meter (400) installed in the urea vaporizer (100) to measure ammonia vaporized from urea, and to warn of clogging. It includes a warning unit 500 that controls the warning unit 500 and a control unit 600 that controls the warning unit 500 based on the measurement of the pressure gauge 300 and the ammonia meter 400.

The urea vaporizer 100 has a combustion gas inlet 110 through which combustion gas flows in at the bottom, a combustion gas outlet 120 through which the incoming combustion gas is discharged is formed at the top, and a combustion gas inlet 110 through which combustion gas flows in is formed at the upper part. As the introduced combustion gas is mixed with urea, the vaporization space 130 guided to the combustion gas outlet 120 is formed larger than the diameter of the combustion gas inlet 110 and the combustion gas outlet 120. Also, a catalyst layer 140 may be formed in the vaporization space 130. The catalyst layer 140 is composed of a selective catalytic reduction (SCR) catalyst layer and may be formed in a mesh shape, such as a porous body.

The urea supply unit 200 includes a nozzle 210 that sprays urea water mixed with urea into the urea vaporizer 100. These nozzles 210 may be composed of a plurality and may be installed symmetrically on both sides while approaching the combustion gas inlet 110 of the urea vaporizer 100. That is, since urea water is injected into the incoming combustion gas through the nozzles 210, mixing of combustion gas and urea water can be easily achieved.

In addition, the urea supply unit 200 includes a pump 220 that supplies urea in a set amount for a set time. That is, since the pump 220 supplies urea through the nozzle 210 only in a set amount, urea can be supplied in a fixed quantity.

The pressure gauge 300 may be installed only at the combustion gas inlet 110 of the urea vaporizer 100, or may be configured in plural and installed at the combustion gas inlet 110 and the combustion gas outlet 120 of the urea vaporizer 100. That is, the pressure gauges 300 measure the pressures of the combustion gas inlet 110 and the combustion gas outlet 120, respectively.

The ammonia meter 400 is installed at the combustion gas outlet 120 of the urea vaporizer 100 and is configured to analyze the ammonia (NH3) concentration.

The warning unit 500 may be configured as an alarm that warns with sound or a warning light that warns with light. Of course, they may be configured and used together.

The control unit 600 includes a pressure confirmation unit 610 for checking the current pressure of the pressure gauge 300, an ammonia confirmation unit 620 for checking the current ammonia of the ammonia meter 400, and a reference pressure and reference ammonia setting. A standard setting unit 630, a determination unit 640 that compares the current ammonia to the standard ammonia to determine whether it matches, and a judgment unit 640 that compares the current pressure to the standard pressure to determine whether it matches the current ammonia. After determining that the ammonia does not match, if it is determined that the current pressure does not match the reference pressure, it includes a warning operation unit 650 that operates the warning unit 500.

The standard setting unit 630 sets the standard ammonia based on the amount of urea supplied by the pump 220 of the urea supply unit 200. That is, if the urea supply amount is large, the standard ammonia concentration is set high, and if the urea supply amount is relatively small, the standard ammonia concentration is set low.

In addition, the standard setting unit 630 compares the pressures initially measured by the pressure gauges 300 and, if they match, sets the matched pressure as the reference pressure.

Therefore, if urea is not easily vaporized and the current ammonia concentration is lower than the reference ammonia, the current pressure is compared to the reference pressure. Also, if the current pressure does not match the standard pressure and a blockage of the urea vaporizer 100 is detected early, the warning unit 500 is activated so that the operator can check this and take action.

In this way, if blockage of the urea vaporizer 100 is detected early and maintenance of the urea vaporizer 100 is performed during a weekend shutdown (WSS) or daily shutdown (DSS) when maintenance is necessary, the power generation facility can be operated stably without stopping the denitrification facility. there is.

In addition, the present invention includes a swirler (700) installed in the urea vaporizer (100) to promote vaporization of urea. The evaporation of urea is promoted by the vortex 700, allowing active mixing of combustion gas and urea. In other words, the conversion rate of urea to ammonia increases, which can further increase the efficiency of denitrification performance.

In this way, urea clogging can be detected early and action can be taken to prevent performance degradation due to vaporizer clogging.

Additionally, the swirler 700 may be configured as a fan operated by the control of the control unit 600. In other words, when the fan rotates, urea may rotate actively.

In addition, the control unit 600 includes a swing operation unit 660 that operates the swirler 700 when the determination unit 640 determines that the current ammonia does not match the reference ammonia.

Therefore, when the warning unit 500 is activated, the swing operation unit 660 operates the swirler 700, so vaporization of urea can be promoted. That is, when the vaporization of urea is promoted and the ammonia concentration increases, the judgment unit 640 determines that the current ammonia matches the reference ammonia. By this, the warning operation unit 650 stops the operation of the warning unit 500.

The operation of the present invention configured as described above is explained as follows.

First, urea stored in a urea storage tank (not shown) is supplied to the urea vaporizer 100 by the pump 220 of the urea supply unit 200. In this state, high-temperature combustion gas at 360°C discharged from a gas turbine (not shown) is supplied to the urea vaporizer 100. At this time, when ammonia generated by promoting urea is mixed with combustion gas and passes through the catalyst layer 140, which is a denitrification facility, NOx is removed.

The reaction temperature of the catalyst layer 140 is about 320 to 400°C, and the NOx removal efficiency is high and the lifespan of the catalyst layer 140 is also extended. Additionally, at temperatures above 400°C, damage to the catalyst layer 140 may occur, causing a reverse reaction. Therefore, it is desirable to maintain the reaction temperature of the catalyst layer 140 at 300°C or more and 400°C or less.

Accordingly, the combustion gas from which NOx has been removed is discharged through the combustion gas outlet 120 of the urea vaporizer 100.

As such, the present invention can be said to be a very useful invention that can be applied and widely used in the relevant field because it can promote stable operation of power generation facilities by detecting clogging of the urea vaporizer at an early stage.

Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the claims described later rather than the detailed description, and the meaning and scope of the claims and their equivalents. All changes or modified forms derived from the concept should be construed as falling within the scope of the present invention.

100: Urea vaporizer 110: Combustion gas inlet
120: combustion gas outlet 130: vaporization space
140: catalyst layer 200: urea supply unit
210: nozzle 220: pump
300: Pressure gauge 400: Ammonia meter
500: warning unit 600: control unit
610: Pressure confirmation unit 620: Ammonia confirmation unit
630: Standard setting unit 640: Judgment unit
650: warning operation unit 660: swing operation unit
700: Swivel machine

Claims (5)

A urea vaporizer (100) that mixes combustion gas discharged from the gas turbine of a power plant with urea and discharges the mixture,
A urea supply unit (200) that supplies urea to the urea vaporizer (100),
A pressure gauge (300) installed in the urea vaporizer (100) to measure pressure,
An ammonia meter (400) installed in the urea vaporizer (100) to measure the concentration of ammonia vaporized from urea,
A warning unit 500 that warns of a blockage phenomenon,
A control unit 600 that controls the warning unit 500 based on the measurement of the pressure gauge 300 and the ammonia meter 400,
It includes a vortexer (700) installed in the urea vaporizer (100) and consisting of a fan to promote vaporization of urea,
The urea vaporizer 100 has a combustion gas inlet 110 through which combustion gas flows in at the bottom, a combustion gas outlet 120 through which the incoming combustion gas is discharged is formed at the top, and a combustion gas inlet 110 through which combustion gas flows in is formed at the upper part. As the introduced combustion gas is mixed with urea, the vaporization space 130, which is guided to the combustion gas outlet 120, is formed larger than the diameter of the combustion gas inlet 110 and the combustion gas outlet 120, and the vaporization space 130 is formed. A catalyst layer 140 is formed,
The catalyst layer 140 is composed of an SCR (Seletive Catalytic Reduction) catalyst layer and is formed in a mesh shape,
Since the high-temperature combustion gas of 360°C discharged from the gas turbine is supplied to the urea vaporizer 100, the reaction temperature of the catalyst layer 140 is about 320 to 400°C, and the NOx removal efficiency is high and the lifespan of the catalyst layer 140 is also extended. become,
The urea supply unit (200) is
A nozzle 210 that sprays urea water mixed with urea into the urea vaporizer 100, and
It includes a pump 220 that supplies urea in a set amount for a set time,
The nozzles 210 are composed of a plurality of nozzles and are installed symmetrically on both sides as they approach the combustion gas inlet 110 of the urea vaporizer 100.
The pressure gauge 300 is composed of a plurality of pressure gauges and is installed at the combustion gas inlet 110 and combustion gas outlet 120 of the urea vaporizer 100,
The control unit 600 is
A pressure confirmation unit 610 that checks the current pressure of the pressure gauge 300,
An ammonia confirmation unit 620 that checks the current ammonia of the ammonia meter 400,
A standard setting unit 630 that sets the standard pressure and standard ammonia,
A determination unit 640 that compares the current ammonia to the standard ammonia to determine whether it matches, and compares the current pressure to the standard pressure to determine whether it matches,
After the determination unit 640 determines that the current ammonia does not match the standard ammonia, if it is determined that the current pressure does not match the standard pressure, a warning operation unit 650 that operates the warning unit 500;
If the determination unit 640 determines that the current ammonia does not match the reference ammonia, it includes a swing operation unit 660 that operates the swirler 700,
The standard setting unit 630 sets the standard ammonia based on the amount of urea supplied by the pump 220 of the urea supply unit 200, and compares the pressures initially measured by the pressure gauges 300 to match each other. An early detection system for blockage of the urea vaporizer of a thermal power plant denitrification facility, which sets the matched pressure as the standard pressure. delete delete delete delete

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