Apparatus for switching urea water hydrolysis product gas and liquid ammonia gas without shutdown

Abstract

The utility model provides a kind of device for switching urea hydrolysis product gas and liquid ammonia gas without stopping, it is related to liquid ammonia evaporation ammonia gas and urea hydrolysis ammonia gas quick switching technical field.The distribution assembly pipeline and valve assembly are installed with conventional ammonia supply valve group on one side, by setting liquid ammonia ammonia valve, hydrolysis ammonia valve and distribution assembly pipeline and valve assembly, the utility model provides a kind of power plant unit without stopping to switch liquid ammonia evaporation ammonia gas and urea hydrolysis ammonia, two different characteristics reducing agent smooth switching, no environmental protection, safety event occurs, construction investment is less, no double ammonia supply valve group is needed, construction quantity is less, save space, switching process will not occur environmental protection exceeds the standard, pollution and other events, no environmental protection cost, switching is simple and easy to operate, stability is high, success rate is high, without stopping switching, no environmental protection, safety event occurs, switch at any time, simple and easy to operate, cost is low.

Description

Technical Field

[0001] This utility model relates to the field of rapid switching technology between liquid ammonia evaporation and urea hydrolysis ammonia, and in particular to a device for switching urea hydrolysis product gas and liquid ammonia gas without shutting down the machine. Background Technology

[0002] According to the National Energy Administration's "Implementation Plan for Centralized Governance of Safety Risks of Hazardous Chemicals in the Power Industry," the urea replacement and renovation project for major hazardous sources should be completed by the end of 2024. Currently, the urea replacement project has been basically completed nationwide. However, in many power plant renovation projects, due to the asynchronous nature of shutdown plans and urea hydrolysis system construction, the shorter construction period of boiler SCR area pipelines compared to the urea hydrolysis system, and the fact that shutdowns are controlled by the power grid dispatch, many uncertainties have resulted in many power plants being unable to put into operation after urea hydrolysis during the renovation process.

[0003] Generally, the following two methods are adopted:

[0004] 1. Initially, liquid ammonia will be used for evaporation operation. After the planned shutdown is completed, urea hydrolysis will be used to start the unit together.

[0005] 2. Two systems, one for urea hydrolysis product vapor and the other for liquid ammonia evaporation gas, will be constructed simultaneously for switching purposes.

[0006] However, the above solution still has problems: it requires shutdown for switching operations, which can easily cause damage to the ecological environment; the operation is cumbersome, which increases the cost of manual operation and learning, and brings many inconveniences.

[0007] Therefore, this utility model provides a device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the machine. Utility Model Content

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the machine.

[0009] To achieve the above objectives, this utility model adopts the following technical solution: a device for switching urea hydrolysis product gas and liquid ammonia gas without shutting down the system, comprising a distribution assembly pipeline and valve components.

[0010] A conventional ammonia supply valve assembly is installed on one side of the distribution assembly piping and valve assembly, and an SCR original flue is installed on the outside of the distribution assembly piping and valve assembly. The SCR original flue is located on one side of the conventional ammonia supply valve assembly.

[0011] The distribution assembly piping and valve assembly are internally equipped with a hydrolyzed ammonia vapor distribution assembly piping. An isolation door is installed at one end of the hydrolyzed ammonia vapor distribution assembly piping. A first hydrolyzed ammonia vapor distribution assembly nozzle, a second hydrolyzed ammonia vapor distribution assembly nozzle, and a third hydrolyzed ammonia vapor distribution assembly nozzle are sequentially installed on one side of the isolation door. The second hydrolyzed ammonia vapor distribution assembly nozzle is located between the first and third hydrolyzed ammonia vapor distribution assembly nozzles. One end of each of the first, second, and third hydrolyzed ammonia vapor distribution assembly nozzles is connected to the original SCR flue.

[0012] The other end of the ammonia vapor distribution assembly pipeline is equipped with a liquid ammonia valve and a hydrolysis ammonia valve. The liquid ammonia valve is located to one side of the hydrolysis ammonia valve. A liquid ammonia valve interface is installed at the end of the liquid ammonia valve away from the hydrolysis ammonia vapor distribution assembly pipeline, and a hydrolysis ammonia valve interface is installed at the end of the hydrolysis ammonia valve away from the hydrolysis ammonia vapor distribution assembly pipeline. This solution solves the problem of switching between liquid ammonia vapor from evaporation and urea hydrolysis ammonia vapor without shutting down the unit, preventing environmental and safety incidents. It ensures normal operation of liquid ammonia vapor from evaporation during unit operation, while simultaneously completing the hot commissioning of the urea hydrolysis system and perfectly completing the switching. It also completes all commissioning and testing of the urea hydrolysis ammonia vapor. Furthermore, when the major hazard source liquid ammonia is withdrawn, the system switches back to liquid ammonia supply, completely consuming the liquid ammonia. This process solves the problems of: non-stop switching, no environmental or safety incidents, on-demand switching, simple operation, and low cost.

[0013] In a preferred embodiment, an SCR original flue gas ammonia valve is installed on the outer side of the hydrolysis ammonia vapor distribution assembly pipeline and on the side near the hydrolysis ammonia valve. The conventional ammonia supply valve group includes an ammonia supply pipeline and a mass flow meter. The mass flow meter is fixedly connected to the outer side of the ammonia supply pipeline. A first connecting pipeline is installed at one end of the ammonia supply pipeline. The end of the first connecting pipeline away from the ammonia supply pipeline is connected to the hydrolysis ammonia vapor distribution assembly pipeline. The mass flow meter is used for data monitoring and processing during the operation of the ammonia supply pipeline. The ammonia supply pipeline is used for connection processing between the conventional ammonia supply valve group and the hydrolysis ammonia vapor distribution assembly pipeline.

[0014] In a preferred embodiment, the distribution assembly piping and valve components and the hydrolyzed ammonia vapor distribution assembly piping are all made of 316L stainless steel. This material improves the protective effect of the equipment. An ammonia-air mixer is installed between the conventional ammonia supply valve group and the original SCR flue. Both ends of the ammonia-air mixer are equipped with second connecting pipes. One end of one of the second connecting pipes extends into the conventional ammonia supply valve group and is connected to one end of the ammonia supply pipeline.

[0015] In one preferred embodiment, an ammonia supply valve is fixedly connected to the outside of one of the second connecting pipes, and one end of the other second connecting pipe extends into the SCR original flue. The ammonia supply valve is used to control the opening and closing of the second connecting pipe. The conventional ammonia supply valve group and the SCR original flue are connected through the second connecting pipe, and the ammonia-air mixer performs ammonia-air mixing treatment.

[0016] In a preferred embodiment, a control panel is installed on the outside of the distribution assembly piping and valve assembly. The distribution assembly piping and valve assembly, mass flow meter, ammonia supply valve, and ammonia-air mixer are all electrically connected to the control panel. The control panel is used to control the operation of the distribution assembly piping and valve assembly, mass flow meter, ammonia supply valve, and ammonia-air mixer, thereby realizing unified management of electrical equipment.

[0017] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0018] By setting up liquid ammonia gas valve, hydrolyzed ammonia gas valve, and distribution assembly pipelines and valve components, this utility model provides a way for power plant units to switch between liquid ammonia evaporation ammonia gas and urea hydrolysis ammonia gas without shutting down. The two reducing agents with different characteristics can be switched smoothly without environmental or safety incidents. The construction investment is low, there is no need for dual ammonia supply valve groups, the construction work is small and space is saved. There will be no environmental exceedance or pollution incidents during the switching process, there are no environmental costs, the switching is simple and easy to operate, the stability is high and the success rate is high.

[0019] This solution enables the unit to switch between liquid ammonia evaporation and urea hydrolysis ammonia gas without shutting down, preventing environmental and safety incidents. It ensures normal operation of the liquid ammonia evaporation system during unit operation, while simultaneously completing the hot commissioning of the urea hydrolysis system and perfectly completing the switchover. It also completes all commissioning and testing of the urea hydrolysis ammonia gas. Furthermore, when the major hazard source of liquid ammonia is withdrawn, the system switches back to liquid ammonia supply, completely consuming the liquid ammonia. This process solves the following problems: non-stop switching, no environmental or safety incidents, switchover at any time, simple operation, and low cost. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the machine, which is provided by this utility model.

[0021] Legend:

[0022] 1. Liquid ammonia valve; 11. Liquid ammonia valve interface;

[0023] 2. Ammonia hydrolysis valve; 21. Ammonia hydrolysis valve interface;

[0024] 3. SCR original flue gas ammonia valve;

[0025] 4. First nozzle of the hydrolyzed ammonia vapor distribution assembly;

[0026] 5. Second nozzle of the hydrolyzed ammonia vapor distribution assembly;

[0027] 6. Third nozzle of the hydrolyzed ammonia vapor distribution assembly;

[0028] 7. Original SCR flue;

[0029] 8. Distribution assembly piping and valve components; 81. Hydrolyzed ammonia vapor distribution assembly piping; 82. First connecting pipe; 83. Isolation door;

[0030] 9. Conventional ammonia supply valve assembly; 91. Ammonia supply pipeline; 92. Mass flow meter; 93. Second connecting pipeline; 94. Ammonia supply valve; 95. Ammonia-air mixer. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] like Figure 1 As shown, this embodiment provides a technical solution: a device for switching urea hydrolysis product gas and liquid ammonia gas without shutting down the machine, including a distribution assembly pipeline and valve assembly 8, a conventional ammonia supply valve group 9 installed on one side of the distribution assembly pipeline and valve assembly 8, and an SCR original flue 7 installed on the outside of the distribution assembly pipeline and valve assembly 8, the SCR original flue 7 being located on one side of the conventional ammonia supply valve group 9.

[0033] In this scheme, a hydrolyzed ammonia vapor distribution assembly pipe 81 is installed inside the distribution assembly pipe and valve assembly 8. An isolation door 83 is installed at one end of the hydrolyzed ammonia vapor distribution assembly pipe 81. A first nozzle 4, a second nozzle 5, and a third nozzle 6 of the hydrolyzed ammonia vapor distribution assembly are installed sequentially on one side of the isolation door 83. The second nozzle 5 of the hydrolyzed ammonia vapor distribution assembly is located between the first nozzle 4 and the third nozzle 6 of the hydrolyzed ammonia vapor distribution assembly. One end of the first nozzle 4, the second nozzle 5, and the third nozzle 6 of the hydrolyzed ammonia vapor distribution assembly are all connected to the original SCR flue 7.

[0034] In this scheme, a liquid ammonia valve 1 and a hydrolysis ammonia valve 2 are installed at the other end of the hydrolysis ammonia vapor distribution assembly pipe 81. The liquid ammonia valve 1 is located on one side of the hydrolysis ammonia valve 2. The end of the liquid ammonia valve 1 away from the hydrolysis ammonia vapor distribution assembly pipe 81 is equipped with a liquid ammonia valve interface 11, and the end of the hydrolysis ammonia valve 2 away from the hydrolysis ammonia vapor distribution assembly pipe 81 is equipped with a hydrolysis ammonia valve interface 21.

[0035] Going further, such as Figure 1 As shown: In this scheme, an SCR original flue ammonia valve 3 is installed on the outside of the hydrolysis ammonia vapor distribution assembly pipeline 81 and on the side close to the hydrolysis ammonia valve 2.

[0036] In this solution, the distribution assembly piping and valve assembly 8 and the hydrolyzed ammonia vapor distribution assembly piping 81 are both made of 316L stainless steel, which improves the protection effect of the equipment.

[0037] Going further, such as Figure 1 As shown: In this scheme, the conventional ammonia supply valve group 9 includes an ammonia supply pipeline 91 and a mass flow meter 92. The mass flow meter 92 is fixedly connected to the outside of the ammonia supply pipeline 91. A first connecting pipeline 82 is installed at one end of the ammonia supply pipeline 91. The end of the first connecting pipeline 82 away from the ammonia supply pipeline 91 is connected to the hydrolysis ammonia vapor distribution assembly pipeline 81. The mass flow meter 92 is used for data monitoring and processing during the operation of the ammonia supply pipeline 91. The ammonia supply pipeline 91 is used for connection processing between the conventional ammonia supply valve group 9 and the hydrolysis ammonia vapor distribution assembly pipeline 81.

[0038] In this scheme, an ammonia-air mixer 95 is installed between the conventional ammonia supply valve group 9 and the original SCR flue 7. Both ends of the ammonia-air mixer 95 are equipped with second connecting pipes 93. One end of one of the second connecting pipes 93 extends into the conventional ammonia supply valve group 9 and is connected to one end of the ammonia supply pipeline 91.

[0039] In this scheme, an ammonia supply valve 94 is fixedly connected to the outside of one of the second connecting pipes 93, and one end of the other second connecting pipe 93 extends into the interior of the original SCR flue 7. The ammonia supply valve 94 is used to control the opening and closing of the second connecting pipe 93. The conventional ammonia supply valve group 9 and the original SCR flue 7 are connected through the second connecting pipe 93, and the ammonia-air mixer 95 performs ammonia-air mixing treatment.

[0040] Going further, such as Figure 1As shown, in this scheme, a control panel is installed on the outside of the distribution assembly pipe and valve assembly 8. The distribution assembly pipe and valve assembly 8, mass flow meter 92, ammonia supply valve 94 and ammonia air mixer 95 are all electrically connected to the control panel. The control panel is used to control the operation of the distribution assembly pipe and valve assembly 8, mass flow meter 92, ammonia supply valve 94 and ammonia air mixer 95, realizing unified management of electrical equipment.

[0041] Working principle:

[0042] like Figure 1 As shown:

[0043] By setting up liquid ammonia gas valve 1, hydrolyzed ammonia gas valve 2, and distribution assembly pipeline and valve components 8, this utility model provides a way for power plant units to switch between liquid ammonia evaporation ammonia gas and urea hydrolysis ammonia gas without shutting down. The two reducing agents with different characteristics can be switched smoothly without environmental or safety incidents. The construction investment is low, there is no need for dual ammonia supply valve groups, the construction work is small and space is saved. There will be no environmental exceedance or pollution incidents during the switching process, there are no environmental costs, the switching is simple and easy to operate, the stability is high and the success rate is high.

[0044] Steps for switching from liquid ammonia supply to urea hydrolysis ammonia gas:

[0045] 1. The original ammonia supply pipeline system remains unchanged and operates normally;

[0046] 2. Before the urea hydrolysis ammonia steam is put into operation, the steam preheating finished steam pipeline is directly opened to the SCR inlet flue spare port;

[0047] 3. After preheating, the hydrolysis ammonia vapor distribution assembly pipeline and valve assembly 8 are not operated. Urea hydrolysis ammonia vapor begins. Unqualified ammonia gas is directly discharged into the original SCR flue 7 to participate in the denitrification reaction.

[0048] 4. When the urea system hydrolyzer has completed the heating and pressurization and is ready for formal operation, quickly close the liquid ammonia gas supply valve 1 after the hydrolysis ammonia vapor distribution assembly, open the gas supply valve of the hydrolysis ammonia vapor distribution assembly, and at the same time close the isolation door 83 from the assembly to the SCR inlet flue.

[0049] 5. Adjust the regulating valve of the ammonia supply valve group;

[0050] 6. Switching successful;

[0051] Steps for switching from urea hydrolysis to ammonia gas to liquid ammonia supply:

[0052] 1. Liquid ammonia is ready for operation;

[0053] 2. Close the gas supply valve from the hydrolysis ammonia vapor distribution assembly to the ammonia supply valve group, and at the same time open the liquid ammonia gas supply valve after the hydrolysis ammonia vapor distribution assembly;

[0054] 3. Open the isolation door 83 from the hydrolysis ammonia vapor distribution assembly to the SCR inlet flue, vent the urea hydrolysis ammonia vapor, and perform steam purging;

[0055] 4. Switching successful;

[0056] The distribution assembly piping and valve assembly 8 and the hydrolyzed ammonia distribution assembly piping 81 are both made of 316L stainless steel, which improves the protective effect of the equipment.

[0057] The mass flow meter 92 is used for data monitoring and processing during the operation of the ammonia supply pipeline 91, which is used for connecting the conventional ammonia supply valve group 9 and the hydrolysis ammonia vapor distribution assembly pipeline 81.

[0058] The ammonia supply valve 94 is used to control the opening and closing of the second connecting pipe 93. The second connecting pipe 93 connects the conventional ammonia supply valve group 9 and the original SCR flue 7. The ammonia-air mixer 95 performs ammonia-air mixing treatment.

[0059] The control panel is used to control the operation of the distribution assembly piping and valve components 8, mass flow meter 92, ammonia supply valve 94 and ammonia-air mixer 95, realizing unified management of electrical equipment.

[0060] This solution enables the unit to switch between liquid ammonia evaporation and urea hydrolysis ammonia gas without shutting down, preventing environmental and safety incidents. It ensures the normal operation of liquid ammonia evaporation during unit operation, completes the hot commissioning of the urea hydrolysis system and perfectly completes the switching, completes all commissioning and testing of urea hydrolysis ammonia gas, and switches back to liquid ammonia supply when the major hazard source liquid ammonia is withdrawn, thus completely consuming the liquid ammonia.

[0061] This process solves the following problems: no shutdown switching, no environmental or safety incidents, switching at any time, simple and easy operation, and low cost.

[0062] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system, comprising a distribution assembly pipeline and valve assembly (8), characterized in that, A conventional ammonia supply valve group (9) is installed on one side of the distribution assembly pipe and valve assembly (8), and an SCR original flue (7) is installed on the outside of the distribution assembly pipe and valve assembly (8). The distribution assembly pipe and valve assembly (8) is equipped with a hydrolyzed ammonia vapor distribution assembly pipe (81). An isolation door (83) is installed at one end of the hydrolyzed ammonia vapor distribution assembly pipe (81). A first nozzle (4), a second nozzle (5), and a third nozzle (6) of the hydrolyzed ammonia vapor distribution assembly are installed sequentially on one side of the isolation door (83). One end of each of the first nozzle (4), the second nozzle (5), and the third nozzle (6) of the hydrolyzed ammonia vapor distribution assembly is connected to the original SCR flue (7). The other end of the hydrolyzed ammonia vapor distribution assembly pipe (81) is equipped with a liquid ammonia valve (1) and a hydrolyzed ammonia valve (2). The liquid ammonia valve (1) is located on one side of the hydrolyzed ammonia valve (2). The end of the liquid ammonia valve (1) away from the hydrolyzed ammonia vapor distribution assembly pipe (81) is equipped with a liquid ammonia valve interface (11). The end of the hydrolyzed ammonia valve (2) away from the hydrolyzed ammonia vapor distribution assembly pipe (81) is equipped with a hydrolyzed ammonia valve interface (21).

2. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the machine, as described in claim 1, is characterized in that: An SCR original flue ammonia valve (3) is installed on the outside of the hydrolyzed ammonia vapor distribution assembly pipe (81) and on the side near the hydrolyzed ammonia valve (2).

3. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system according to claim 1, characterized in that: The conventional ammonia supply valve assembly (9) includes an ammonia supply pipeline (91) and a mass flow meter (92). The mass flow meter (92) is fixedly connected to the outside of the ammonia supply pipeline (91). A first connecting pipeline (82) is installed at one end of the ammonia supply pipeline (91). The end of the first connecting pipeline (82) away from the ammonia supply pipeline (91) is connected to the hydrolysis ammonia vapor distribution assembly pipeline (81).

4. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system according to claim 1, characterized in that: The distribution assembly pipe and valve assembly (8) and the hydrolyzed ammonia vapor distribution assembly pipe (81) are both made of 316L stainless steel.

5. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system according to claim 3, characterized in that: An ammonia-air mixer (95) is installed between the conventional ammonia supply valve group (9) and the original SCR flue (7). Both ends of the ammonia-air mixer (95) are equipped with second connecting pipes (93), one end of which extends into the conventional ammonia supply valve group (9) and is connected to one end of the ammonia supply pipeline (91).

6. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system according to claim 5, characterized in that: One of the second connecting pipes (93) is fixedly connected to an ammonia supply valve (94) on the outside, and one end of the other second connecting pipe (93) extends into the interior of the original SCR flue (7).

7. The device for switching between urea hydrolysis product gas and liquid ammonia gas without shutting down the system according to claim 6, characterized in that: A control panel is installed on the outside of the distribution assembly piping and valve assembly (8), and the distribution assembly piping and valve assembly (8), mass flow meter (92), ammonia supply valve (94) and ammonia air mixer (95) are all electrically connected to the control panel.

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