Safe emission structure for ammonia pollution discharge of urea hydrolysis station of power plant

Abstract

The invention relates to the technical field of ammonia gas emission, and discloses a safe emission structure for ammonia gas pollution discharge of a urea hydrolysis station of a power plant. The gas outlet end of the ammonia discharge pipe is connected with a negative pressure mixing mechanism, a water inlet pipe is arranged at the axis of the negative pressure mixing mechanism, and ammonia gas in the ammonia discharge pipe is sucked and discharged after being mixed with a jet medium by utilizing a negative pressure suction effect generated in the negative pressure mixing mechanism by jet flow in the water inlet pipe; ammonia gas and demineralized water are sucked and mixed through the negative pressure mixing mechanism to form ammonia water to be discharged, and the problem of emission pollution caused by the fact that the ammonia gas is directly discharged into an open type sewage pool is avoided; a rotational flow groove of the pipe throat section converts jet flow into rotational flow, and gas-liquid contact is enhanced; the stirring piece of the conical section rotates by means of rotational flow kinetic energy, bubbles are further broken, mixing is enhanced, the dissolution rate of ammonia gas is greatly increased, volatilization is reduced, the safety of the operation environment is guaranteed, pollution to the surrounding environment is avoided, and safe and environment-friendly treatment of the ammonia gas is achieved.

Description

Technical Field

[0001] This invention relates to the field of ammonia emission technology, and in particular to a safe emission structure for ammonia discharge in a power plant urea hydrolysis station. Background Technology

[0002] Liquid ammonia storage tanks have a high risk factor. Most power plants in China have replaced liquid ammonia storage tanks with hydrolysis or pyrolysis urea treatment. The treatment workshops are collectively referred to as urea stations. The main equipment in the urea station is the hydrolyzer. The working principle of the hydrolyzer is to use steam heating to hydrolyze urea and produce ammonia, which is used by the unit to remove nitrogen oxides in the flue gas and achieve the purpose of achieving the emission standard of flue gas.

[0003] Urea hydrolysis is a process of urea evaporation. Most of the urea is hydrolyzed to produce ammonia, and a small portion is discharged through the middle and bottom sewage pipes in a regular sewage discharge, and then through the ditch to the wastewater pond.

[0004] Because the urea plant is located in an enclosed indoor environment, the sewage discharge pipe from the hydrolyzer to the ditch is an open discharge pipe. During the sewage discharge process of the hydrolyzer, a large amount of ammonia gas is generated. When the operators operate the valves for sewage discharge, they will directly inhale the gas, causing discomfort to their bodies. Mild cases may experience a pungent odor and cough, while severe cases may experience tearing, chest tightness, and shortness of breath. The three hydrolyzers are discharged 7-8 times a week. Each time the operators discharge the sewage from the hydrolyzers, they inhale a large amount of ammonia gas. Even wearing ordinary masks provides limited protection and is extremely harmful to the human body. Summary of the Invention

[0005] In view of the problems existing in the safe emission structure for ammonia wastewater discharge in the urea hydrolysis station of the power plant, the present invention is proposed.

[0006] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a safe emission structure for ammonia gas discharge in a power plant urea hydrolysis station, comprising,

[0007] Ammonia discharge pipe;

[0008] The outlet end of the ammonia discharge pipe is connected to the negative pressure mixing mechanism. The negative pressure mixing mechanism is equipped with a water inlet pipe at its axial center. The jet in the water inlet pipe generates a negative pressure suction effect in the negative pressure mixing mechanism, which draws in the ammonia gas in the ammonia discharge pipe and mixes it with the jet medium before discharging it.

[0009] In a preferred embodiment of the safe emission structure for ammonia discharge in a power plant urea hydrolysis station of the present invention: the negative pressure mixing mechanism includes a shell that is a cylindrical hollow body;

[0010] Both ends of the outer shell have through holes for the water inlet pipe to pass through, and the gap between the interior of the outer shell and the water inlet pipe forms a negative pressure chamber. One end of the outer shell is connected to a discharge pipe, and the end of the outer shell connected to the discharge pipe has an air intake hole that connects the discharge pipe and the negative pressure chamber.

[0011] When demineralized water is introduced into the inlet pipe, a jet is formed at its outlet end and enters the discharge pipe. The jet drives the air flow, which draws the air in the negative pressure chamber out through the air intake to form a negative pressure, thereby drawing out the ammonia gas discharged from the ammonia discharge pipe and achieving the mixing of ammonia gas and demineralized water.

[0012] In a preferred embodiment of the safe discharge structure for ammonia wastewater discharge in a power plant urea hydrolysis station described in this invention: the discharge pipe includes an intake section and a throat section. The jet ejected from the inlet pipe enters the throat section through the intake section. Since the inner diameter of the intake section is larger than the inner diameter of the throat section, the jet forms a velocity gradient when flowing through the intake section, thereby driving the gas to flow together with the jet and achieving a suction effect.

[0013] In a preferred embodiment of the safe discharge structure for ammonia wastewater discharge at the urea hydrolysis station of the power plant described in this invention: a dispersion component is connected to the liquid outlet end of the discharge pipe. The dispersion component is used to reduce the flow velocity of the gas-liquid mixed jet discharged through the discharge pipe, so as to avoid the fluid directly impacting the wastewater tank, thereby reducing the occurrence of splashing and disturbance.

[0014] In a preferred embodiment of the safe discharge structure for ammonia discharge in a power plant urea hydrolysis station described in this invention: the dispersion component includes a conical section and an L-shaped section, one end of the L-shaped section is connected to the large-diameter end of the conical section, and the other end of the L-shaped section is vertically downward close to the liquid surface of the sewage tank, and the small-diameter end of the conical section is connected to the liquid outlet end of the pipe throat section.

[0015] In a preferred embodiment of the safe discharge structure for ammonia discharge in the urea hydrolysis station of the power plant described in this invention: the inner wall of the pipe throat section has swirling grooves, which are equidistantly distributed along the inner circumference of the pipe throat section. These grooves are used to change the incoming jet into a swirling flow. The swirling flow causes the gas-liquid mixed jet to rotate around the axis, promoting faster dissolution of ammonia in the demineralized water and reducing the escape of undissolved ammonia.

[0016] In a preferred embodiment of the safe emission structure for ammonia discharge in the urea hydrolysis station of the power plant described in this invention: the swirl channel extends along the inner wall of the pipe throat section in a spiral trajectory, and the tangent direction of the swirl channel always maintains a fixed helical angle with the axis of the pipe throat section.

[0017] In a preferred embodiment of the safe discharge structure for ammonia discharge in the urea hydrolysis station of the power plant described in this invention: the conical section is provided with an agitator, which drives itself to rotate by the kinetic energy generated by the swirling flow, thereby achieving further mixing of ammonia and demineralized water.

[0018] In a preferred embodiment of the safe emission structure for ammonia discharge in the urea hydrolysis station of the power plant described in this invention: a liquid surface flotation absorption mechanism is provided on the outside of the L-shaped section for secondary capture and recovery of ammonia gas escaping above the liquid surface of the sewage tank.

[0019] In a preferred embodiment of the safe discharge structure for ammonia gas discharge in a power plant urea hydrolysis station described in this invention: the liquid surface flotation absorption mechanism includes a ring, which is a hollow structure and is assembled on the outside of an L-shaped section via a bracket. Holes are equidistantly opened on the outer circumference of the ring, and a guide pipe is provided at the bottom of the ring. The outlet end of the guide pipe extends into the interior of the L-shaped section, and a turbulence-inducing component is assembled at the outlet end of the guide pipe. The turbulence-inducing component rotates under the impact of the downward water flow and drives the airflow at the outlet of the guide pipe to draw in the ammonia gas escaping from above the liquid surface of the sewage tank through the holes.

[0020] The beneficial effects of this invention are as follows: This invention utilizes a negative pressure mixing mechanism to draw and mix ammonia gas with demineralized water to form ammonia water for discharge, thus avoiding the emission pollution problem caused by ammonia gas being directly discharged into an open sewage tank;

[0021] The swirl channel in the throat section transforms the jet into a swirling flow, enhancing gas-liquid contact; the agitator in the conical section rotates using the kinetic energy of the swirling flow, further breaking up bubbles and strengthening mixing, significantly improving the ammonia dissolution rate and reducing volatilization. This ensures a safe operating environment and avoids pollution to the surrounding environment, achieving safe and environmentally friendly ammonia treatment. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein:

[0023] Figure 1 A three-dimensional structural diagram of the safe emission structure for ammonia wastewater discharge at a power plant urea hydrolysis station is shown.

[0024] Figure 2 A cross-sectional view of the negative pressure mixing mechanism in the safety emission structure for ammonia wastewater discharge at a power plant urea hydrolysis station is shown.

[0025] Figure 3 A cross-sectional view of the discharge pipe fittings in the safety discharge structure for ammonia wastewater at a power plant urea hydrolysis station is shown.

[0026] Figure 4 The diagram shows the structure of the dispersed components in the safe emission structure for ammonia wastewater discharge at a power plant urea hydrolysis station.

[0027] Figure 5The diagram shows the structure of the agitator in the safety discharge structure for ammonia gas discharge at the urea hydrolysis station of a power plant;

[0028] Figure 6 The assembly diagram of the liquid surface flotation absorption mechanism in the safety discharge structure for ammonia gas discharge in the urea hydrolysis station of a power plant is shown.

[0029] Figure 7 This diagram shows the structure of the liquid surface flotation absorption mechanism in the safety discharge structure for ammonia gas discharge at a power plant urea hydrolysis station;

[0030] Figure 8 The diagram shows the structure of the agitator in the safety discharge structure for ammonia wastewater at the urea hydrolysis station of a power plant. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0032] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0033] Reference Figure 1-3 This embodiment provides a safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station, including:

[0034] Ammonia discharge pipe 1;

[0035] The outlet end of the ammonia discharge pipe 1 is connected to the negative pressure mixing mechanism 2. The negative pressure mixing mechanism 2 is equipped with a water inlet pipe 3 at its axis. The jet in the water inlet pipe 3 generates a negative pressure suction effect in the negative pressure mixing mechanism 2, which draws in the ammonia in the ammonia discharge pipe 1 and mixes it with the jet medium before discharging it.

[0036] It should be noted that although ammonia is extremely soluble in water, when the ammonia discharge pipe 1 is directly inserted into the liquid submerged in the sewage tank, the ammonia released from the pipe opening will instantly dissolve in water and generate a large number of bubbles. The bubbles may accumulate around the pipe opening and form an air blockage (i.e., the resistance to gas release suddenly increases, causing the pressure inside the ammonia pipe to rise sharply).

[0037] Excessive back pressure may exceed the pressure limit of pipelines or equipment, causing ammonia leakage (such as loose joints or broken pipelines); if the amount of ammonia released is large, the rapid rise of a large number of bubbles may also agitate the liquid in the pool, causing sewage to splash. Ammonia-containing sewage is corrosive and irritating, which may cause harm to surrounding facilities or personnel.

[0038] Therefore, hydrolysis plants all adopt open discharge, but some ammonia gas will be released into the air. When operators enter the area, inhaling it will cause harm to their health.

[0039] Therefore, this application uses demineralized water as a medium to mix ammonia gas with demineralized water to form ammonia water, thereby reducing its volatility and toxicity, and then discharges it into an open sewage pond, thus avoiding the problem of ammonia gas floating in the air and causing harm to people in the area.

[0040] The negative pressure mixing mechanism 2 includes a shell 21 that is a cylindrical hollow body;

[0041] Both ends of the outer shell 21 are provided with through holes for the water inlet pipe 3 to pass through, and the gap between the interior of the outer shell 21 and the water inlet pipe 3 forms a negative pressure chamber 22. One end of the outer shell 21 is connected to a discharge pipe 23, and the end of the outer shell 21 connected to the discharge pipe 23 is provided with a suction hole 24 that connects the discharge pipe 23 and the negative pressure chamber 22.

[0042] The outlet end of the inlet pipe 3 has a conical structure. When the demineralized water is transported to the conical structure, the cross-sectional area gradually decreases along the water flow direction, resulting in a significant increase in flow velocity and the formation of a high-speed jet. This jet enters the discharge pipe 23, and the jet drives the air flow, drawing the air in the negative pressure chamber 22 out through the air intake hole 24 to form a negative pressure. This negative pressure then draws out the ammonia gas discharged from the ammonia discharge pipe 1, achieving the mixing of ammonia gas and demineralized water.

[0043] The discharge pipe 23 includes an intake section 231 and a throat section 232. The jet ejected from the inlet pipe 3 enters the throat section 232 through the intake section 231. Since the inner diameter of the intake section 231 is larger than the inner diameter of the throat section 232, the jet forms a velocity gradient when it flows through the intake section 231, thereby driving the gas to flow with the jet and achieving a suction effect. Under the suction effect, the air in the negative pressure chamber 22 is drawn out through the intake hole 24 to form a negative pressure. The negative pressure is used to draw out the ammonia gas in the ammonia discharge pipe 1 and mix it with the demineralized water entering the intake section 231 to form ammonia water.

[0044] Specifically, the ammonia discharge pipe 1 is connected to the ammonia storage tank. Opening the discharge valve allows the ammonia in the storage tank to enter the ammonia discharge pipe 1. When discharge is required, the demineralized water supply valve is first opened, allowing the demineralized water to enter the discharge fitting 23 from the inlet pipe 3. The jet-driven airflow creates a negative pressure chamber 22. At this time, opening the discharge valve creates suction, which quickly draws the ammonia in the ammonia discharge pipe 1 into the suction section 231 to mix with the demineralized water, forming ammonia water. This ammonia water is then discharged from the discharge fitting 23 into the sewage tank. Since the ammonia has already mixed with the demineralized water, the ammonia water enters the sewage tank in liquid form during the discharge process, which can significantly reduce the volatility of ammonia. Even if the ammonia water mixes with the water in the sewage tank, the dilution effect of the water further weakens the release potential of ammonia, thus effectively preventing undissolved ammonia from directly drifting into the air. This fundamentally eliminates the health risk of operators inhaling ammonia when entering the area, and also reduces the odor pollution of ammonia to the surrounding environment, balancing discharge safety and environmental protection.

[0045] Preferably, the inner wall of the throat section 232 has swirling grooves 2321, which are equidistantly distributed along the inner circumference of the throat section 232 to change the incoming jet into a swirling flow. The swirling flow causes the gas-liquid mixed jet to generate a rotational motion around the axis, which promotes the faster dissolution of ammonia in the demineralized water and reduces the escape of undissolved ammonia.

[0046] The swirl channel 2321 extends along the inner wall of the throat section 232 in a spiral trajectory, and the tangent direction of the swirl channel 2321 always maintains a fixed helical angle with the axis of the throat section 232. The helical angle is the acute angle formed in space by the tangent of the swirl channel 2321 and the axis of the throat section, and it remains constant throughout the entire extension range of the swirl channel 2321, so that the swirl channel 2321 is spirally distributed along the pipe wall with a uniform inclined trend, thereby providing a stable rotational guide for the jet flowing through it.

[0047] When the mixed jet of demineralized water and ammonia enters the throat section 232, the edge of the jet contacts the wall of the swirl channel 2321. Since the swirl channel 2321 extends obliquely along a fixed helical angle, its guiding effect will apply a continuous tangential force to the jet, so that the jet that originally flows along the axial direction gradually acquires a tangential velocity component that rotates around the axis. As the jet advances in the throat section 232, the rotational motion is continuously strengthened, eventually forming a stable spiral flow pattern (swirl).

[0048] This design utilizes a structure where swirling channels 2321 are distributed equidistantly along the inner wall of the throat section 232 at a fixed helical angle. When the mixed jet of demineralized water and ammonia enters the throat section 232, the jet edge contacts the wall of the swirling channel 2321. With the inclined guiding effect of the swirling channel 2321, it is continuously subjected to tangential force, causing the originally axially flowing jet to gradually acquire a tangential velocity around the axis of rotation. As the rotational motion is continuously strengthened, a stable spiral swirling flow is eventually formed. This design utilizes the interaction between the fluid and the wall of the swirling channel 2321 to efficiently realize the conversion of the jet into a swirling flow. It can promote the radial diffusion of the liquid through centrifugal force, cut the ammonia into small bubbles and disperse them evenly, greatly increase the gas-liquid contact area and collision frequency to accelerate dissolution and reduce the escape of undissolved gas.

[0049] As an optional embodiment:

[0050] Reference Figure 4 In one embodiment provided in this application, the liquid outlet end of the discharge pipe 23 is connected to a dispersion component 4. The dispersion component 4 is used to reduce the flow rate of the gas-liquid mixed jet discharged through the discharge pipe 23, so as to avoid the fluid directly impacting the sewage tank, thereby reducing the occurrence of splashing and disturbance.

[0051] It should be noted that the jet flow rate discharged from the discharge pipe 23 is very high. Direct discharge into the sewage tank will cause a large splash. The splash will cause the ammonia-containing sewage to spread to the surrounding area of ​​the tank, which will not only cause corrosive damage to the surrounding equipment and ground, but may also increase the ammonia concentration in the air of the operating area due to the volatilization of ammonia gas from the splashed droplets, increasing the risk of personnel inhalation. At the same time, the violent disturbance will stir up the sediment at the bottom of the sewage tank, causing the settled pollutants to be resuspended, affecting the subsequent sewage treatment effect.

[0052] The dispersion component 4 includes a conical section 41 and an L-shaped section 42. One end of the L-shaped section 42 is connected to the large-diameter end of the conical section 41, and the other end of the L-shaped section 42 is vertically downward close to the liquid surface of the sewage tank. The small-diameter end of the conical section 41 is connected to the liquid outlet end of the pipe throat section 232.

[0053] When the swirling gas-liquid mixture jet enters the conical section 41 of the dispersion component 4 from the throat section 232, the cross-sectional area of ​​the flow continues to increase as the inner diameter of the conical section 41 gradually expands along the flow direction (transitioning from the small diameter end to the large diameter end).

[0054] According to the principle of conservation of momentum in fluid mechanics, the axial velocity of the swirling flow in the conical section 41 gradually decreases as the cross-section expands. At the same time, its rotational kinetic energy is partially converted into pressure energy during the expansion process, which weakens the helical motion intensity of the swirling flow and the fluid gradually transitions from a strong swirling state to a slow flow state.

[0055] When the fluid enters the L-shaped section 42, its flow direction changes from axial to vertically downward. The turning resistance of the 90° bend further consumes the remaining kinetic energy. In addition, the straight section of the L-shaped section 42 has a constant diameter structure, which can keep the fluid velocity in a stable and decaying state. Finally, through the combined effect of the diameter expansion and deceleration of the conical section 41 and the turning energy consumption of the L-shaped section 42, the gas-liquid mixture is discharged from the end of the L-shaped section 42 in a low velocity and low kinetic energy state. The outlet position is close to the liquid surface of the sewage tank, which further shortens the acceleration distance of the fluid during the falling process and ensures that it flows into the sewage in a nearly gentle manner, fundamentally eliminating the splashing and disturbance caused by the direct impact of the high-speed jet on the liquid surface.

[0056] As an optional embodiment:

[0057] Reference Figure 5 In one embodiment provided in this application, the conical section 41 is provided with an agitator 5. The agitator 5 is driven to rotate by the kinetic energy generated by the swirling flow, thereby achieving further mixing of ammonia and demineralized water.

[0058] The agitator 5 includes a bracket 51, a fixed shaft 52 is fixed at one end of the bracket 51, and an impeller 53 is rotatably sleeved on the fixed shaft 52.

[0059] To enhance the mixing of ammonia and demineralized water, the kinetic energy of the swirling flow is used to drive the impeller 53 to rotate, further creating mechanical disturbance to the gas-liquid mixture within the conical section 41. During rotation, the blades of the impeller 53 cut and tear bubble clusters in the fluid, breaking larger ammonia bubbles into finer microbubbles. Simultaneously, it disrupts the stable flow field structure formed by the swirling flow, causing more intense relative motion and turbulent mixing between the gas and liquid phases. This significantly increases the frequency and area of ​​gas-liquid contact, promoting more complete combination of undissolved ammonia with the demineralized water, improving the uniformity of the ammonia solution and the ammonia dissolution rate, reducing secondary volatilization of ammonia during subsequent discharge, and ensuring that the residual ammonia in the final mixture discharged into the wastewater tank is minimized.

[0060] The fixed shaft 52 is a hollow structure, and the bracket 51 has a circular hole 54 that communicates with the hollow structure. The circular hole 54 and the hollow structure of the fixed shaft 52 form a through channel to reduce the flow obstruction to the gas-liquid mixture.

[0061] As an optional embodiment:

[0062] It should be noted that when ammonia water falls into the sewage tank from top to bottom along the L-shaped section 42, it will disrupt the surface tension of the liquid and form a ring wave when it impacts the surface of the sewage tank. This will cause violent disturbances at the gas-liquid interface. The disruption of the surface tension reduces the resistance of dissolved ammonia molecules in the sewage to break free from the interface. The turbulence generated by the wave and the impact will cause the ammonia molecules originally dissolved in the sewage to desorb rapidly. At the same time, the local vortex and pressure fluctuation formed below the liquid surface during the impact will further promote the transfer of ammonia from the liquid phase to the gas phase, ultimately causing the ammonia to be released upward in the form of a diffused gas into the space above the surface of the sewage tank.

[0063] Therefore, refer to Figure 6-8 In one embodiment provided in this application, a liquid surface flotation absorption mechanism 6 is provided on the outside of the L-shaped section 42 for secondary capture and recovery of ammonia gas escaping above the liquid surface of the sewage tank. A recovery area can be formed in the escaping area above the sewage tank to secondary capture and recover the residual ammonia gas in the area, thereby solving the problem of ammonia gas escaping.

[0064] Specifically, the liquid surface flotation absorption mechanism 6 includes a ring 61, which is a hollow structure. The ring 61 is assembled to the outside of the L-shaped section 42 via a bracket 62. Holes 63 are equidistantly opened on the outer periphery of the ring 61. A guide pipe 64 is provided at the bottom of the ring 61. The outlet end of the guide pipe 64 extends into the interior of the L-shaped section 42. A turbulence component 65 is installed at the outlet end of the guide pipe 64. The turbulence component 65 rotates under the impact of the downward water flow and drives the airflow at the outlet of the guide pipe 64 to draw in the ammonia gas escaping from the surface of the sewage tank through the holes 63.

[0065] Specifically, the turbulence component 65 includes a circular cover 651, which is fixed to the air outlet of the guide pipe 64. The circular cover 651 has an inlet 652 and an outlet 653 respectively at the upper and lower sides of the air outlet of the guide pipe 64. A water wheel 654 is rotatably connected inside the circular cover 651. Ammonia water enters from the inlet 652 and slides down the outer wall of the guide pipe 64 onto the water wheel 654. The water wheel 654 will rotate due to the impact of the ammonia water. When rotating, the blades of the water wheel 654 will generate airflow turbulence in the outlet area of ​​the guide pipe 64 due to the high speed during rotation, forming a negative pressure zone. This can generate suction in the ring 61, which will collect the ammonia gas escaping above the liquid surface of the sewage tank and mix it with the ammonia water again before discharging, thus minimizing the escape of ammonia gas.

[0066] A triangular block 655 is installed above the circular cover 651, located on one side of the liquid inlet 652. The triangular block 655 forms an acute angle with the inclined surface on the guide pipe 64. The water flow discharged from the L-shaped section 42 impacts the triangular block 655 and slides quickly down its inclined surface to the acute angle area, which can form a flow-gathering effect and enhance the impact of the water flow on the water wheel 654. This design enhances the impact force of the water flow on the water wheel 654 by converging the flow through the triangular block 655, causing the water wheel 654 to rotate and form a negative pressure, continuously drawing in the escaped ammonia gas. At the same time, the recovered ammonia gas is directly mixed with ammonia water, and the absorption effect is enhanced by the solubility of ammonia water. No additional power is required to achieve highly efficient and energy-saving secondary recovery of ammonia gas and significantly reduce escape.

[0067] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station, characterized in that: include, Ammonia discharge pipe (1); The outlet end of the ammonia discharge pipe (1) is connected to the negative pressure mixing mechanism (2). The negative pressure mixing mechanism (2) is provided with a water inlet pipe (3) at its axis. The jet in the water inlet pipe (3) generates a negative pressure suction effect in the negative pressure mixing mechanism (2), which draws in the ammonia in the ammonia discharge pipe (1) and mixes it with the jet medium before discharging it.

2. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 1, characterized in that: The negative pressure mixing mechanism (2) includes a shell (21) that is a cylindrical hollow body; Both ends of the outer shell (21) are provided with through holes for the water inlet pipe (3) to pass through, and the gap between the interior of the outer shell (21) and the water inlet pipe (3) forms a negative pressure chamber (22). One end of the outer shell (21) is connected to a discharge pipe (23), and the end of the outer shell (21) connected to the discharge pipe (23) is provided with an air intake hole (24) that connects the discharge pipe (23) and the negative pressure chamber (22). When demineralized water is introduced into the inlet pipe (3), a jet is formed at its outlet end and enters the discharge pipe (23). The jet drives the air to flow, and the air in the negative pressure chamber (22) is drawn out through the air intake hole (24) to form a negative pressure, thereby drawing out the ammonia gas discharged from the ammonia discharge pipe (1) and realizing the mixing of ammonia gas and demineralized water.

3. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 2, characterized in that: The discharge pipe (23) includes an air intake section (231) and a throat section (232). The jet ejected from the water inlet pipe (3) enters the throat section (232) through the air intake section (231). Since the inner diameter of the air intake section (231) is larger than the inner diameter of the throat section (232), the jet forms a velocity gradient when it flows through the air intake section (231), thereby driving the gas to flow together with the jet and realizing the suction effect.

4. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 3, characterized in that: The outlet end of the discharge pipe (23) is connected to a dispersion component (4). The dispersion component (4) is used to reduce the flow rate of the gas-liquid mixture jet discharged through the discharge pipe (23) to avoid the fluid directly impacting the sewage tank, thereby reducing the occurrence of splashing and disturbance.

5. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 4, characterized in that: The dispersion component (4) includes a conical section (41) and an L-shaped section (42). One end of the L-shaped section (42) is connected to the large-diameter end of the conical section (41), and the other end of the L-shaped section (42) is vertically downward close to the liquid surface of the sewage tank. The small-diameter end of the conical section (41) is connected to the liquid outlet end of the throat section (232).

6. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 5, characterized in that: The inner wall of the throat section (232) has swirling grooves (2321), which are equidistantly distributed along the inner circumference of the throat section (232) to change the incoming jet into a swirling flow. The swirling flow causes the gas-liquid mixed jet to rotate around the axis, promoting faster dissolution of ammonia in the demineralized water and reducing the escape of undissolved ammonia.

7. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 6, characterized in that: The swirling groove (2321) extends along the inner wall of the throat section (232) in a spiral trajectory, and the tangential direction of the swirling groove (2321) always maintains a fixed helical angle with the axis of the throat section (232).

8. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 7, characterized in that: The conical section (41) is equipped with an agitator (5), which is driven to rotate by the kinetic energy generated by the swirling flow, thereby achieving further mixing of ammonia and demineralized water.

9. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 5, characterized in that: The L-shaped section (42) is equipped with a liquid surface flotation absorption mechanism (6) for secondary capture and recovery of ammonia gas escaping above the liquid surface of the sewage tank.

10. The safe emission structure for ammonia wastewater discharge in a power plant urea hydrolysis station according to claim 9, characterized in that: The liquid surface flotation absorption mechanism (6) includes a ring (61), which is a hollow structure. The ring (61) is assembled on the outside of the L-shaped section (42) by a bracket (62). Holes (63) are equidistantly opened on the outer periphery of the ring (61). A guide pipe (64) is provided at the bottom of the ring (61). The outlet end of the guide pipe (64) extends into the interior of the L-shaped section (42). A turbulence component (65) is assembled at the outlet end of the guide pipe (64). The turbulence component (65) rotates under the impact of the water flow from top to bottom and drives the airflow at the outlet of the guide pipe (64) to draw in the ammonia gas escaping above the liquid surface of the sewage tank through the holes (63).

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