KR102419575B1 - Apparatus and system for decomposing urea with dual configuration - Google Patents

Abstract

Urea hydrolysis apparatus according to exemplary embodiments, a reactor for receiving urea water, a first heat exchange member disposed in the reactor, a second heat exchange member disposed in the reactor and spaced apart from the first heat exchange member in a first direction and at least one sensor disposed between the first heat exchange member and the second heat exchange member in a plan view.

Description

Urea hydrolysis device and urea hydrolysis system with dual configuration

The present invention relates to a urea hydrolysis device. More particularly, the present invention relates to a urea hydrolysis device and a urea hydrolysis system having a dual configuration to increase reliability and lifespan.

In the case of combustion engines such as power plant boilers, incinerators and diesel engines, nitrogen oxides (NOx) are generated by combustion. These nitrogen oxides can act as a cause of increasing air pollution and fine dust. Accordingly, the need and regulations for nitrogen oxide removal in combustion engines are increasing.

A reducing agent is used to decompose nitrogen oxides into nitrogen and oxygen, and ammonia is used as the reducing agent. However, in the case of ammonia, transportation and storage are not easy, so a technique for generating/using ammonia by hydrolyzing urea is used.

The hydrolysis of urea may proceed in a reactor, and a heat exchanger may be used for the progress of the hydrolysis. Since the reactor and the heat exchanger are exposed to a high temperature aqueous solution of urea, there is a risk of corrosion.

One object of the present invention is to provide a urea hydrolysis device and a urea hydrolysis system with increased reliability and durability.

The urea hydrolysis apparatus according to exemplary embodiments for achieving the object of the present invention includes a reactor accommodating urea water, a first heat exchange member disposed in the reactor, and the first heat exchange member disposed in the reactor and a second heat exchange member spaced apart in the first direction, and at least one sensor disposed between the first heat exchange member and the second heat exchange member in a plan view.

According to an embodiment, steam is selectively provided to the first heat exchange member and the second heat exchange member.

According to an embodiment, the at least one sensor includes a first temperature sensor, a second temperature sensor spaced apart from the first temperature sensor, a first liquid level sensor, and a second liquid level sensor spaced apart from the first liquid level sensor do. The first temperature sensor, the second temperature sensor, the first liquid level sensor, and the second liquid level sensor are arranged along a second direction perpendicular to the first direction.

According to an embodiment, the first liquid level sensor and the second liquid level sensor include a surface stabilization guide that surrounds the surface of the urea water in the measurement area of the non-contact sensor and the non-contact sensor, respectively, and is partially submerged in the urea water do.

A urea hydrolysis system according to exemplary embodiments for achieving an object of the present invention includes a reactor for discharging ammonia gas generated through the urea hydrolysis reaction of urea water and a heating unit for heating the urea water in the reactor include The heating unit includes a steam supply unit, a condensate discharge unit, and first and second heat exchangers connected in parallel to the steam supply unit and the condensate discharge unit. The first heat exchanger includes a first heat exchange member disposed in the reactor, and the second heat exchanger is a second heat exchange member spaced apart from the first heat exchange member in the reactor and extending in the same direction as the first heat exchange member includes Steam is selectively provided to the first heat exchange member and the second heat exchange member.

According to an embodiment, steam is provided to the first heat exchange member in a normal operation mode, and when the temperature of the reactor exceeds the limit temperature or the pressure of the reactor exceeds the limit pressure, it is applied to the first heat exchange member. The provided steam is blocked, and the steam is provided to the second heat exchange member.

According to an embodiment, the control unit further includes a control unit for adjusting the amount of steam provided to the first heat exchange member or the second heat exchange member based on the temperature, pressure, and liquid level of the reactor.

According to one embodiment, the urea hydrolysis system, a first temperature sensor and a second temperature sensor for measuring the temperature of the reactor, respectively, a first liquid level sensor and a second liquid level sensor for measuring the liquid level of the reactor, respectively, and It further includes a first pressure sensor and a second pressure sensor for measuring the pressure of the reactor, respectively.

According to one embodiment, the control unit, when the difference between the first measured temperature measured by the first temperature sensor and the second measured temperature measured by the second temperature sensor exceeds a certain range, the difference is A measurement temperature with continuity before and after the occurrence is selected as the normal measurement temperature.

According to an embodiment, the control unit may be configured to: When a difference between a first measured liquid level measured by the first liquid level sensor and a second measured liquid level measured by the second liquid level sensor exceeds a certain range, the The measured liquid level with continuity before and after the point of time difference is selected as the normal measured liquid level.

According to an embodiment, the control unit, when a difference between the first measured pressure measured by the first pressure sensor and the second measured pressure measured by the second pressure sensor exceeds a certain range, the difference is A measurement pressure with continuity before and after the occurrence is selected as the normal measurement pressure.

According to an embodiment, the first temperature sensor, the second temperature sensor, the first liquid level sensor, and the second liquid level sensor are disposed between the first heat exchange member and the second heat exchange member in a plan view.

According to an embodiment, each of the first heat exchange member and the second heat exchange member includes a tube bundle.

According to exemplary embodiments, there is provided a urea hydrolysis system having a partially dual configuration. Accordingly, it is possible to effectively improve the stability and durability of the urea hydrolysis system while minimizing the increase in cost and installation space.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be variously expanded without departing from the spirit and scope of the present invention.

1 is a schematic configuration diagram showing a urea hydrolysis system according to an embodiment of the present invention.
2 is a plan view illustrating a reactor, a sensor, and a heat exchanger of a urea hydrolysis system according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line II′ of FIG. 2 .
FIG. 4 is a cross-sectional view taken along line II-II' of FIG. 2 .
5 is a cross-sectional view taken along line III-III' of FIG. 2 .

With respect to the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are only exemplified for the purpose of describing the embodiments of the present invention, and the embodiments of the present invention may be embodied in various forms. It should not be construed as being limited to the embodiments described in .

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle. Other expressions describing the relationship between elements, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, and is one or more other features or numbers , it should be understood that it does not preclude the possibility of the presence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with the context of the related art, and unless explicitly defined in the present application, they are not to be interpreted in an ideal or excessively formal meaning. .

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

1 is a schematic configuration diagram showing a urea hydrolysis system according to an embodiment of the present invention.

Referring to FIG. 1 , the urea hydrolysis system includes a reactor 10 , a urea water supply unit 20 , a heating unit 30 , and a control unit 40 .

The urea water supply unit 20 provides urea water into the reactor 10 through the urea water inlet 12 of the reactor 10 . The heating unit 30 may heat the urea water in the reactor 10 . Urea (NH ₄ CONH ₂ ) dissolved in the urea water reacts with water (H ₂ O) to form ammonium carbamate (NH ₂ CONH ₄ ). Ammonium carbamate decomposes to ammonia and carbon dioxide. Ammonia and carbon dioxide thus generated may be discharged through the gas outlet 14 of the reactor 10 and transferred to a nitrogen oxide reduction device or a storage space.

<Urea hydrolysis reaction formula>

NH ₄ CONH ₂ + H ₂ O → NH ₂ CONH ₄

NH ₂ CONH ₄ → 2NH ₃ + CO2

The control unit 40 may control the hydrolysis reaction in the reactor 10 . According to one embodiment, the control unit 40 may control the amount of urea water provided to the reactor (10). In addition, the reaction temperature of the reactor 10 may be adjusted by adjusting the amount of steam provided to the heat exchanger of the heating unit 30 . Through this, the hydrolysis reaction rate in the reactor 10 can be controlled.

The urea hydrolysis system may further include a urea water controller 22 for controlling the amount of urea water provided to the reactor 10 from the urea water supply unit 20 .

The heating unit 30 is connected to the steam providing unit 32 and the steam providing unit 32 , and is connected to a heat exchanger that is at least partially inserted into the reactor 10 , and is connected to the heat exchanger in the heat exchanger. and a condensed water discharge unit 34 from which the generated condensed water is discharged, and a steam controller 36 for controlling the amount of steam provided to the heat exchanger by controlling the discharge amount of the condensed water.

For example, each of the regulators may include a valve coupled to a urea supply pipe, a steam supply pipe, or a condensate discharge pipe.

The urea hydrolysis system may further include a sensor. For example, the urea hydrolysis system, a temperature sensor for detecting the reaction temperature of the reactor 10, a pressure sensor for measuring the pressure of the reactor 10, and measuring the height of the urea water in the reactor (10) It may include a liquid level sensor. According to an embodiment, the temperature sensor and the liquid level sensor may be coupled to the reactor 10 . The pressure sensor is not directly coupled to the reactor 10, but is connected to a urea water supply pipe that delivers the urea water, and can measure the internal pressure of the urea water supply pipe. When the pressure sensor is installed in the reactor 10, the reliability of the measured pressure may be reduced due to precipitation of solids generated in the urea hydrolysis reaction.

Information measured from the sensors may be transmitted to the controller 40 . The control unit 40, based on the transmitted information, the reaction temperature, the pressure, and the height of the urea water to maintain a preset value or range, the urea water controller 22 and the condensed water controller 36 ) can be controlled.

According to one embodiment, the sensors have a dualized configuration. For example, the first temperature sensor T1 and the second temperature sensor T2 measure the reaction temperature of the reactor 10, respectively, and the first liquid level sensor L1 and the second liquid level sensor L2 are each Measure the height of the number of urea in the reactor (10). The first pressure sensor P1 and the second pressure sensor P2 respectively measure the pressure of the reactor 10 .

The first measured temperature, the second measured temperature, the first measured pressure, the second measured pressure, the first measured liquid level, and the second measured liquid level measured by the sensors may be transmitted to the controller 40 . When the sensors operate normally, the temperature, pressure, and liquid level measured by the sensors may be the same or may be maintained with a difference within an error range.

If one sensor malfunctions due to damage or the like, the difference between the values increases. For example, when the difference between the first measured temperature and the second measured temperature exceeds a preset range, the controller 30 selects a temperature having continuity with the value before the difference occurs as the normal measured temperature. do. For example, when the first measured temperature measured by the first temperature sensor T1 has continuity before and after a time point when the difference between the first measured temperature and the second measured temperature occurs, the first measured temperature is selected as the normal measurement temperature.

Similarly to the above, when the difference between the first pressure and the second pressure exceeds a preset range, the control unit 30 may select a measurement pressure having continuity with the value before the difference occurs as the normal measurement pressure. have. In addition, when the difference between the first liquid level and the second pressure exceeds a preset range, the control unit 30 selects the measured liquid level having continuity with the value before the difference occurs as the normal measured liquid level. can

As described, the urea hydrolysis system according to an embodiment of the present invention has a dual sensor configuration, so that even if any one sensor malfunctions or loses a function, the hydrolysis reaction can be stably performed.

The hydrolysis reaction proceeds at a high temperature (100° C. or higher). Accordingly, there is a possibility of corrosion in the reactor and heat exchanger exposed to high temperature urea water. In particular, in the case of a heat exchanger, since steam having a temperature higher than the reaction temperature is provided, it may be more susceptible to corrosion. In the case of a double configuration of the entire system in order to ensure the stability of the urea hydrolysis system, the cost and space required are large.

The urea hydrolysis system according to an embodiment of the present invention may include a preliminary heat exchanger in the reactor to increase the stability and lifespan of the system without duplicating the entire system. This will be described later.

2 is a plan view illustrating a reactor, a sensor, and a heat exchanger of the urea hydrolysis system according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line II′ of FIG. 2 . FIG. 4 is a cross-sectional view taken along line II-II' of FIG. 2 . 5 is a cross-sectional view taken along line III-III' of FIG. 2 .

The reactor, sensor and heat exchanger of the urea hydrolysis system according to an embodiment of the present invention may be understood as constituting the urea hydrolysis device.

1 and 2 , the heating unit 30 includes a first heat exchanger H1 and a second heat exchanger H2. The first heat exchanger H1 may include a first heat exchange member HT1 disposed in the reactor 10 . The second heat exchanger H2 may include a second heat exchange member HT2 disposed in the reactor 10 .

According to an embodiment, in a plan view, the first heat exchange member HT1 and the second heat exchange member HT2 may be horizontally spaced apart from each other in a first direction D1, and the first heat exchange member HT1 may be spaced apart from each other in the first direction D1. It may extend along the second direction D2 perpendicular to the . For example, the first heat exchange member HT1 and the second heat exchange member HT2 may be respectively inserted into the reactor 10 from one side of the reactor 10 . The second heat exchange member HT2 may have substantially the same configuration as the first heat exchange member HT1 . Each of the first heat exchange member HT1 and the second heat exchange member HT2 may include a plurality of tube bundles.

Referring to FIG. 3 , the first heat exchange member HT1 may be completely submerged in the urea water US in the reactor 10 . Steam is provided from the outside to the first heat exchange member HT1. For example, the steam delivered to the first heat exchange member HT1 through the steam inlet SI has a temperature higher than that of the urea water US, and passes through the first heat exchange member HT1. Heat is transferred to the urea water US outside the heat exchange member HT1 and is condensed. After the condensed water CW exits from the first heat exchange member HT1 , it may be transferred to the outside through the condensed water outlet CO outside the reactor 10 .

Referring to FIG. 1 , the first heat exchanger H1 and the second heat exchanger H2 are connected in parallel to a steam supply unit 32 and a condensate discharge unit 34 . The second heat exchanger H2 may have a preliminary configuration. Accordingly, the second heat exchanger H2 may have substantially the same configuration as the first heat exchanger H1 .

For example, in a normal operation mode of the urea hydrolysis system, steam may be provided to the first heat exchanger H1 , and steam may be blocked in the second heat exchanger H2 . When the first heat exchanger H1 malfunctions or does not operate due to damage or the like, that is, in the auxiliary operation mode, steam is blocked in the first heat exchanger H1 and steam is supplied to the second heat exchanger H2 This can be provided. The normal operation mode may be referred to as a first mode, and the auxiliary operation mode may be referred to as a second mode.

For example, the heating unit 30 may include an opening/closing selector 38 connected to the condensate discharge valves of the first heat exchanger H1 and the second heat exchanger H2 . For example, the opening/closing selector 38 opens the condensate discharge valve of the first heat exchanger H1 in the normal operation mode, closes the condensate discharge valve of the second heat exchanger H2, and the auxiliary operation In the mode, the condensate discharge valve of the first heat exchanger H1 may be locked and the condensed water discharge valve of the second heat exchanger H2 may be opened. For example, the opening/closing selection unit 38 may be manually operated by an operator, or may be connected to the control unit 40 and automatically operated according to a predetermined condition.

For example, when the normal reaction temperature of the hydrolysis reaction is 150° C. to 160° C. and the normal pressure is 3 kg/cm 2 to 8 kg/cm 2 , the limiting temperature is 160° C. and the limiting pressure can be set to 8 kg/cm 2 .

When a problem occurs in the heat exchanger in operation, for example, when the heat exchange member is damaged, as steam flows out into the reactor 10 , the temperature and pressure may increase abnormally. For example, when at least one of the measured temperature and the measured pressure of the reactor 10 exceeds the limiting temperature or the limiting pressure, the controller 40 controls the opening/closing selector 38 to control the first The condensate discharge valve of the heat exchanger H1 may be closed, and the condensed water discharge valve of the second heat exchanger H2 may be opened. As a result, even when the first heat exchanger H1 does not operate or malfunctions, the urea hydrolysis reaction may be continuously performed.

In addition, even if the first heat exchanger H1 is not damaged, when a foreign material layer is formed by adsorption of ions in the urea water, heat exchange efficiency may be reduced due to a heat insulation effect. In this case, by withdrawing the first heat exchanger (H1) and operating the second heat exchanger (H2) while cleaning the first heat exchanger (H1), the heat exchanger is reduced while minimizing the interruption of the urea hydrolysis reaction. Can be replaced/repaired.

Embodiments of the present invention provide a sensor configuration capable of effectively measuring the information of the reactor in the configuration having the preliminary heat exchanger as described above.

3 to 5 , the first temperature sensor T1 , the second temperature sensor T2 , the first liquid level sensor L1 , and the second liquid level sensor L2 are, in a plan view, the first heat exchange member It may be disposed between the HT1 and the second heat exchange member HT2. For example, the first temperature sensor T1 , the second temperature sensor T2 , the first liquid level sensor L1 , and the second liquid level sensor L2 may be arranged along the second direction D2 . . For example, the first temperature sensor T1 , the second temperature sensor T2 , the first liquid level sensor L1 , and the second liquid level sensor L2 may include the first heat exchange member HT1 and the second heat exchange member L2 . It may be spaced apart from the member HT2 by the same distance.

The first temperature sensor T1 and the second temperature sensor T2 may be coupled to the upper end of the reactor 10, and for measuring the reaction temperature (urea water temperature), a part of each of the urea water (US ) can be submerged in A gas outlet 14 may be disposed between the first temperature sensor T1 and the second temperature sensor T2 . However, embodiments of the present invention are not limited thereto, and the position of the gas outlet 14 may be changed as needed.

The first liquid level sensor L1 and the second liquid level sensor L2 may include non-contact sensors L1a and L2a and surface stability guides L1b and L2b, respectively. The non-contact sensors L1a and L2a may be wireless detection sensors such as RADAR. The surface of the urea water (US) is not stable due to gas generation by hydrolysis at high temperature. The surface stabilization guides L1b and L2b flatly surround the surface of the area measured by the non-contact sensors L1a and L2a to separate it from the rest of the area. Accordingly, since the height of the surface in the measurement area is maintained constant, measurement reliability can be improved. For example, the surface stabilization guides L1b and L2b may have a cylindrical shape, and a part may be submerged in the urea number US.

According to the configuration, as the sensors are disposed between the first heat exchange member HT1 and the second heat exchange member HT2 and are spaced apart by the same distance, even when the second heat exchange member HT2 operates Reaction information similar to reaction information measured when the first heat exchange member HT1 operates may be obtained. Accordingly, even in the auxiliary operation mode, the reaction can be controlled based on reliable information.

According to embodiments of the present invention, there is provided a urea hydrolysis system having a partially dual configuration. Accordingly, it is possible to effectively improve the stability and durability of the urea hydrolysis system while minimizing the increase in cost and installation space.

The present invention can be used to produce ammonia for the reduction of nitrogen oxides in combustion plants with combustion engines, such as power plants, incinerators, and the like.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

10: reactor
12: urea water inlet
14: gas outlet
20: urea water supply unit
22: urea number regulator
30: heating unit
H1: first heat exchanger
H2: second heat exchanger
32: steam supply
34: condensate outlet
36: steam regulator
38: open/close selection unit
40: control unit
L1: first liquid level sensor
L2: second liquid level sensor
T1: first temperature sensor
T2: second temperature sensor
P1: first pressure sensor
P2: second pressure sensor

Claims (13)

delete delete delete delete A reactor for discharging ammonia gas generated through the urea hydrolysis reaction of urea water; and
A heating unit for heating the urea water in the reactor,
The heating unit,
steam supply;
condensate outlet; and
A first heat exchanger and a second heat exchanger connected in parallel to the steam supply unit and the condensate discharge unit,
The first heat exchanger includes a first heat exchange member disposed in the reactor, and the second heat exchanger is spaced apart from the first heat exchange member in the reactor and extends in the same first direction as the first heat exchange member. comprising a heat exchange member;
Steam is selectively provided to the first heat exchange member and the second heat exchange member,
steam is provided to the first heat exchange member in a normal operating mode;
When the temperature of the reactor exceeds the limiting temperature or the pressure of the reactor exceeds the limiting pressure, the steam provided to the first heat exchange member is cut off, and the steam is provided to the second heat exchange member,
The first heat exchange member and the second heat exchange member are spaced apart from each other in a second direction perpendicular to the first direction, and at least one sensor is disposed between the first heat exchange member and the second heat exchange member in a plan view, The urea hydrolysis system of claim 1, wherein at least one sensor is spaced the same distance from the first heat exchange member and the second heat exchange member. delete 6. The method of claim 5,
The urea hydrolysis system, characterized in that it further comprises a control unit for adjusting the amount of steam provided to the first heat exchange member or the second heat exchange member based on the temperature, pressure, and liquid level of the reactor. The method of claim 7, wherein the at least one sensor comprises:
a first temperature sensor and a second temperature sensor for measuring the temperature of the reactor, respectively;
a first liquid level sensor and a second liquid level sensor for measuring the liquid level of the reactor, respectively; and
Urea hydrolysis system, characterized in that it further comprises a first pressure sensor and a second pressure sensor for respectively measuring the pressure of the reactor. The method of claim 8, wherein the control unit, when the difference between the first measured temperature measured by the first temperature sensor and the second measured temperature measured by the second temperature sensor exceeds a certain range, the difference is A urea hydrolysis system, characterized in that a measurement temperature having continuity before and after the occurrence time is selected as a normal measurement temperature. According to claim 8, wherein the control unit, When the difference between the first measured liquid level measured by the first liquid level sensor and the second measured liquid level measured by the second liquid level sensor exceeds a certain range, the A urea hydrolysis system, characterized in that the measured liquid level having continuity before and after the point of time difference is selected as the normal measured liquid level. The method of claim 8, wherein the control unit, when the difference between the first measured pressure measured by the first pressure sensor and the second measured pressure measured by the second pressure sensor exceeds a certain range, the difference is A urea hydrolysis system, characterized in that a measurement pressure having continuity before and after the occurrence time is selected as a normal measurement pressure. delete 6. The urea hydrolysis system according to claim 5, wherein the first heat exchange member and the second heat exchange member each comprise a tube bundle.

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