Ammonia synthesis reaction water circulation system

Abstract

The invention discloses an ammonia synthesis reaction water circulation system which comprises a combustion furnace, a boiler, an acid making device and a make-up pump, the boiler comprises a furnace body, the top of the furnace body is integrally connected with a furnace top, the furnace top is in an outwards-protruding cone shape, the cone-shaped top is connected with a gas outlet header pipe in a communicating mode, and a water inlet pipe is arranged at the bottom of the furnace body; the heat exchange pipeline is in a spring pipeline shape and is horizontally and transversely arranged in an inner cavity of the furnace body, an air outlet hole is formed in the top of the tail end of the heat exchange pipeline, the height of the air outlet hole is larger than the drainage liquid level of the furnace body, and the hole diameter of the air outlet hole is smaller than the inner diameter of the heat exchange pipeline. The ammonia synthesis reaction water circulation system is high in heat exchange efficiency, the function of automatically circulating condensed water accumulated on the bottom wall in the heat exchange pipeline can be achieved, and waste of water resources is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic ammonia, and in particular relates to an ammonia synthesis reaction water circulation system. Background Art

[0002] Synthetic ammonia refers to ammonia directly synthesized from nitrogen and hydrogen under high temperature, high pressure and in the presence of a catalyst. It is a basic inorganic chemical process. In the modern chemical industry, ammonia is the main raw material for the fertilizer industry and basic organic chemicals.

[0003] In the ammonia synthesis chemical process reaction, the desulfurization and decarbonization device will produce H 2 If the acid gas containing H2S is directly discharged, it will not only pollute the environment, but also cause waste of resources. In the prior art, the corresponding treatment and reuse can be used to treat the acid gas containing H2S. 2 S's acid gas is converted; its process is as follows Figure 1 As shown, the desulfurization and decarbonization unit produces H 2 The acidic gas containing S is first transported to the combustion furnace and burned with oxygen to produce SO 2 The high-temperature hot steam is sent to the boiler (the principle of oxygen combustion reaction is: 2H 2 S+3O 2 →2SO 2 +2H 2 O+reaction heat), the boiler recovers the heat and uses it to heat the circulating water, and finally SO 2 Gas and hot water are fed into the dry acid plant to produce industrial products H 2 SO 4 (Principle of dry acid production: 2SO 2 +O 2 →2SO 3 , SO 3 +H 2 O(heat) → H 2 SO 4 ), and the remaining water is returned to the boiler for reheating, thus forming a water cycle, achieving comprehensive resource utilization while avoiding environmental pollution.

[0004] In the prior art, SO 2 The principle of heat recovery boiler of high temperature hot steam is as follows Figure 2 and Figure 3 As shown, it includes: an outer shell, an annular inner shell, an air inlet pipe, an air outlet pipe, a water inlet pipe and a water outlet pipe. An annular water cavity containing water is formed between the inner wall of the outer shell and the outer wall of the annular inner shell, containing SO 2 The high-temperature hot steam enters the inner cavity of the annular inner tank from the air inlet pipe and is finally discharged from the air outlet pipe at the top. 2The heat carried by the high-temperature hot steam heats the water in the annular water cavity; it has the following disadvantages: 1. The heat exchange efficiency is low; 2. After the heat exchange, the condensed water drips along the inner wall of the annular liner to the bottom of the annular liner, which is difficult to reuse. Summary of the invention

[0005] The present invention aims at solving the problems in the prior art and proposes the following technical solutions:

[0006] The ammonia synthesis reaction water circulation system includes a combustion furnace, a boiler, an acid making device and a water supply pump. The boiler includes:

[0007] A furnace body, the top of the furnace body is integrally connected with a furnace roof, the furnace roof is in a cone shape protruding outwards and the top of the cone shape is interconnected with a gas outlet main pipe, and a water inlet pipe is arranged at the bottom of the furnace body;

[0008] A heat exchange pipe, the heat exchange pipe is in the shape of a spring pipe and is horizontally placed in the inner cavity of the furnace body, an air outlet is opened at the top of the end of the heat exchange pipe, the height of the air outlet is higher than the drainage level of the furnace body and the aperture of the air outlet is smaller than the inner diameter of the heat exchange pipe;

[0009] The SO formed by burning the acid gas in the combustion furnace 2 The hot steam enters the inner cavity of the furnace body through the heat exchange pipe. The spring pipe-shaped heat exchange pipe in the inner cavity of the furnace body increases the heat exchange between the hot steam and the circulating water in the furnace body. After the heat exchange, the gas overflows upward from the gas outlet and is finally transported to the acid making device through the gas outlet main pipe.

[0010] As a preferred embodiment of the above technical solution, a heat exchange component is fixedly connected to the inner walls of the furnace body and the furnace top, and the heat exchange component includes a base plate fixedly connected to the inner wall of the furnace body, and a heat exchange plate is fixedly connected to the top of the base plate. The heat exchange plate is arc-shaped, and the arc-shaped inner concave surface of one of the heat exchange plates is located above the air outlet.

[0011] As a preferred embodiment of the above technical solution, side plates are integrally fixedly connected to both sides of the heat exchange plate, and the side plates extend downward from the top of the heat exchange plate along the curvature of the heat exchange plate.

[0012] As a preferred embodiment of the above technical solution, a water outlet pipe is interconnected on the side wall of the furnace body, and the water outlet pipe and the drainage liquid level in the inner cavity of the furnace body are flush.

[0013] As a preferred embodiment of the above technical solution, a pressure-adaptive drainage mechanism is provided at the bottom of the heat exchange pipe, and the pressure-adaptive drainage mechanism extends to the inner cavity of the water inlet pipe.

[0014] As a preferred embodiment of the above technical solution, the pressure-adaptive drainage mechanism includes a connecting pipe interconnected with the bottom of the heat exchange pipe, and the bottom of the connecting pipe is fixedly inserted on the water inlet pipe, a connecting hole is opened on the side wall of the connecting pipe, and a pressure-adaptive drainage component is arranged inside the connecting pipe.

[0015] As a preferred embodiment of the above technical solution, the connecting pipe is in a shape of an outer circle and an inner square, and the outer diameter of the connecting pipe is smaller than the inner diameter of the water inlet pipe.

[0016] As a preferred embodiment of the above technical solution, the pressure-following drainage component includes a piston in the inner cavity of a connecting pipe, a Y-shaped connecting cavity is opened inside the piston, a first magnetic block is fixedly connected to the inner wall of the connecting pipe, a second magnetic block is embedded and fixedly connected to the top of the piston, and the second magnetic block is opposite to the first magnetic block, and a spring is fixedly connected between the piston and the inner wall of the bottom of the connecting pipe.

[0017] As a preferred embodiment of the above technical solution, a lower stop block is fixedly connected to the inner wall of the connecting pipe, and the lower stop block is located below the connecting hole.

[0018] The beneficial effects of the present invention are:

[0019] 1. The boiler of the present invention is supplemented with cold circulating water from the water inlet pipe, so that the inner cavity of the furnace body always maintains a certain height of circulating water, the drainage liquid level is lower than the height of the air outlet, but the heat exchange pipe is not less than 90% immersed in the circulating water; SO 2 The high-temperature hot steam enters the furnace cavity through the heat exchange pipe. The heat exchange pipe in the furnace cavity is in the shape of a horizontally placed spring pipe. Therefore, compared with the straight tube channel in the prior art, the spring pipe-shaped heat exchange pipe can have more sufficient contact with the circulating water, increasing the SO 2 The path and time of high-temperature hot steam in the pipeline are greatly improved, thereby greatly improving the heat transfer efficiency;

[0020] 2. In the present invention, the spring-shaped heat exchange pipe increases the SO 2 The high-temperature hot steam travels in the pipeline and takes longer time, so the hot steam gets better heat transfer and heat consumption, and the moisture in the hot steam can be better condensed into water droplets, greatly reducing SO 2 The water content in the gas reduces the subsequent SO 2 Furthermore, the arc-shaped heat exchange plate can further contact with the remaining hot steam in the buffer chamber, condense into water droplets on the surface of the heat exchange plate and flow into the circulating water along the heat exchange plate, which not only further increases the heat transfer efficiency, but also further reduces SO 2The water content in the gas is determined by the arc-shaped inner concave surface of one heat exchange plate being located above the air outlet, which can prevent the condensed water discharged from the air outlet from splashing, so that it can flow into the circulating water along the arc-shaped inner concave surface of the heat exchange plate; by setting the bottom plate, the contact area between the side of the heat exchange plate and the buffer cavity can be further increased, further increasing the heat transfer efficiency and reducing SO 2 The amount of water in the gas;

[0021] 3. The SO2-containing 2 After the high-temperature hot steam and circulating water exchange heat, the moisture in the hot steam will condense into water droplets and flow to the bottom along the inner wall of the heat exchange pipe; in a round of transportation stage, the initial stage (0~t1) and the decay stage (t2~t3), the air pressure in the heat exchange pipe cavity is less than P. At this time, if Figure 8 As shown in the figure, the second magnetic block is attracted to the first magnetic block, and the spring is in a compressed state, providing an upward elastic force for the piston. At this time, the Y-shaped connecting cavity and the connecting hole are not connected; when the air pressure in the inner cavity of the heat exchange pipe is greater than P at the peak stage (t1-t2), the air pressure is greater than the sum of the magnetic attraction of the first magnetic block and the second magnetic block + the spring elastic force, and the piston is pushed down to the position shown in the figure. Fig. 9 As shown in the state, the bottom of the piston is against the lower block, and the Y-shaped connecting cavity and the connecting hole are connected. At this time, the condensed water accumulated at the bottom of the heat exchange pipe is successively merged into the inner cavity of the water inlet pipe through the Y-shaped connecting cavity and the connecting hole, and finally merged into the circulating water, thereby realizing the automatic circulation function of the condensed water accumulated on the bottom wall of the heat exchange pipe, reducing the waste of water resources, and avoiding the influence of the condensed water inside the heat exchange pipe on the subsequent gas transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a flow chart of the ammonia synthesis reaction water circulation system;

[0023] Figure 2 The figure shows a schematic diagram of the three-dimensional structure of a boiler in the prior art of the ammonia synthesis reaction water circulation system;

[0024] Figure 3 The figure shows a front view of the structure of a boiler in the prior art of the ammonia synthesis reaction water circulation system;

[0025] Figure 4 The figure shows a schematic diagram of the three-dimensional structure of the boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0026] Figure 5 The bottom view of the internal structure of the boiler in the ammonia synthesis reaction water circulation system in the embodiment is shown;

[0027] Figure 6 The figure shows a top view of the internal structure of the boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0028] Figure 7 The burner is shown delivering SO2-containing gas to the boiler. 2 High temperature hot steam rate-time diagram;

[0029] Figure 8 The diagram shows a closed state of the pressure-appropriate drainage mechanism in the boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0030] Fig. 9 The diagram shows the opening state of the pressure-adaptive drainage mechanism in the boiler in the ammonia synthesis reaction water circulation system in the embodiment.

[0031] In the figure: 10, furnace body; 11, furnace top; 20, heat exchange pipe; 21, air outlet; 30, air outlet main pipe; 40, water outlet pipe; 50, water inlet pipe; 60, heat exchange component; 61, heat exchange plate; 62, side plate; 63, bottom plate; 70, pressure-appropriate drainage mechanism; 71, connecting pipe; 711, connecting hole; 72, first magnetic block; 73, piston; 731, Y-type connecting cavity; 74, second magnetic block; 75, lower block; 76, spring. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0033] Example

[0034] When the ammonia synthesis reaction water circulation system of the present invention is in operation, the desulfurization and decarbonization device generates H 2 The acidic gas containing S is transported to the combustion furnace through a pipeline and burned at high temperature using oxygen. 2 The high-temperature hot steam is sent to the boiler of the present invention, and the boiler recovers the heat and uses it to heat the circulating water, and finally SO 2 Gas and hot water are fed into the dry acid plant to produce industrial products H 2 SO 4 Finally, the remaining water returns and is supplemented by the external water pump to the boiler for reheating, thus forming a water cycle.

[0035] like Figure 4 , Figure 5 As shown, the boiler of the present invention comprises:

[0036] A furnace body 10, the top of the furnace body 10 is integrally connected with a furnace top 11, the furnace top 11 is in a cone shape protruding outwards and the top of the cone shape is interconnected with a gas outlet main pipe 30, and a water inlet pipe 50 is provided at the bottom of the furnace body 10;

[0037] The heat exchange pipe 20 is in the shape of a spring pipe and is horizontally placed in the inner cavity of the furnace body 10. An air outlet 21 is opened at the top of the end of the heat exchange pipe 20. The height of the air outlet 21 is higher than the drainage level of the furnace body 10 and the aperture of the air outlet 21 is smaller than the inner diameter of the heat exchange pipe 20.

[0038] The boiler of the present invention is replenished with cold circulating water from the water inlet pipe 50, so that the inner cavity of the furnace body 10 always maintains a certain height of circulating water, and the drainage liquid level is lower than the height of the air outlet 21, but the heat exchange pipe 20 is not less than 90% immersed in the circulating water; SO 2 The high-temperature hot steam enters the inner cavity of the furnace body 10 through the heat exchange pipe 20. The heat exchange pipe 20 located in the inner cavity of the furnace body 10 is in the shape of a horizontally placed spring pipe. Therefore, compared with the straight-tube channel in the prior art, the spring-pipe-shaped heat exchange pipe 20 can have more sufficient contact with the circulating water, thereby increasing the SO 2 The path and time of high-temperature hot steam in the pipeline are shortened, thereby greatly improving the heat transfer efficiency.

[0039] It should be noted that in the dry acid plant, SO 2 Gas reaction produces SO 3 Before that, you need to 2 The gas is filtered to remove SO 2 The moisture in the gas is mixed, and in the present invention, the spring-shaped heat exchange pipe 20 increases the SO 2 The high-temperature hot steam travels in the pipeline and takes longer time, so the hot steam gets better heat transfer and heat consumption, and the moisture in the hot steam can be better condensed into water droplets, greatly reducing SO 2 The water content in the gas reduces the subsequent SO 2 The burden of gas impurity removal;

[0040] Furthermore, a heat exchange assembly 60 is fixedly connected to the inner walls of the furnace body 10 and the furnace top 11. The heat exchange assembly 60 includes a bottom plate 63 fixedly connected to the inner wall of the furnace body 10. A heat exchange plate 61 is fixedly connected to the top of the bottom plate 63. The heat exchange plate 61 is in an arc shape.

[0041] A buffer cavity is formed in the inner cavity of the boiler of the present invention above the drainage level and below the bottom of the outlet main pipe 30. The upper half of the arc-shaped heat exchange plate 61 is located in the buffer cavity, and the lower half is located in the circulating water. The buffer cavity contains SO 2 Gas and SO 2 The remaining hot steam brought out by the gas can be further contacted with the remaining hot steam in the buffer chamber by the arc-shaped heat exchange plate 61, and condensed into water droplets on the surface of the heat exchange plate 61 and flowed into the circulating water along the heat exchange plate 61, which not only further increases the heat transfer efficiency, but also further reduces SO 2 The amount of water in the gas;

[0042] The SO is discharged at the outlet 21. 2 The gas will carry a portion of condensed water formed after heat exchange. The arc-shaped inner concave surface of one of the heat exchange plates 61 is located above the air outlet 21, which can prevent the condensed water discharged from the air outlet 21 from splashing, so that it can flow into the circulating water along the arc-shaped inner concave surface of the heat exchange plate 61.

[0043] Furthermore, the two sides of the heat exchange plate 61 are integrally fixedly connected with side plates 62, and the side plates 62 extend downward from the top of the heat exchange plate 61 along the curvature of the heat exchange plate 61. By providing the bottom plate 63, the contact area between the side of the heat exchange plate 61 and the buffer cavity can be further increased, and the heat transfer efficiency can be further increased, and the SO 2 The water content in the gas.

[0044] The side wall of the furnace body 10 is interconnected with a water outlet pipe 40, and the water outlet pipe 40 is flush with the drainage liquid level in the inner cavity of the furnace body 10. The other end of the water outlet pipe 40 is connected to the dry acid making device to provide hot water to the dry acid making device. Compared with cold water, hot water can better react with SO 3 The gas reacts to produce H 2 SO 4 .

[0045] like Figure 7 As shown, the combustion furnace is transporting SO2-containing gas to the boiler. 2 The high-temperature hot steam rate-time diagram includes an initial stage (0-t1), initial combustion, and incomplete combustion; a peak stage (t1-t2), a full combustion stage; and a decay stage (t2-t3), when the combustion materials decrease and the combustion decays. Since the inner diameter of the heat exchange pipe 20 and the aperture of the air outlet 21 are constant, as the transport rate increases, the gas pressure in the inner cavity of the heat exchange pipe 20 increases, and vice versa. In the present invention, in the initial stage (0-t1) and the decay stage (t2-t3), the gas pressure in the inner cavity of the heat exchange pipe 20 is less than P; in the peak stage (t1-t2), the gas pressure in the inner cavity of the heat exchange pipe 20 is greater than P.

[0046] like Figure 8 , Fig. 9 As shown, a pressure-adapting drainage mechanism 70 is provided at the bottom of the heat exchange pipe 20 , and the pressure-adapting drainage mechanism 70 extends to the inner cavity of the water inlet pipe 50 .

[0047] The pressure-adaptive drainage mechanism 70 includes a connecting pipe 71 interconnected with the bottom of the heat exchange pipe 20, and the bottom of the connecting pipe 71 is fixedly plugged into the water inlet pipe 50, a connecting hole 711 is provided on the side wall of the connecting pipe 71, and a pressure-following drainage component is arranged inside the connecting pipe 71. The connecting pipe 71 is in the shape of an outer circle and an inner square, and the outer diameter of the connecting pipe 71 is smaller than the inner diameter of the water inlet pipe 50. The pressure-following drainage component includes a piston 73 in the inner cavity of the connecting pipe 71, a Y-shaped connecting cavity 731 is provided inside the piston 73, a first magnetic block 72 is fixedly connected to the inner wall of the connecting pipe 71, a second magnetic block 74 is embedded and fixedly connected to the top of the piston 73, and the second magnetic block 74 is directly opposite to the first magnetic block 72, and a spring 76 is fixedly connected between the piston 73 and the inner wall at the bottom of the connecting pipe 71. A lower stopper 75 is fixedly connected to the inner wall of the connecting pipe 71, and the lower stopper 75 is located below the connecting hole 711.

[0048] In the present invention, the SO2-containing 2 After the high-temperature hot steam and the circulating water have heat exchanged, the moisture in the hot steam will condense into water droplets and flow along the inner wall of the heat exchange pipe 20 to the bottom; in a round of transportation stage, the initial stage (0-t1) and the decay stage (t2-t3), the air pressure in the inner cavity of the heat exchange pipe 20 is less than P. At this time, if Figure 8 As shown, the second magnetic block 74 and the first magnetic block 72 are attracted to each other, and the spring 76 is in a compressed state, providing an upward elastic force for the piston 73. At this time, the Y-shaped connecting cavity 731 and the connecting hole 711 are not connected; when the air pressure in the inner cavity of the heat exchange pipe 20 is greater than P at the peak stage (t1-t2), the air pressure is greater than the sum of the magnetic attraction of the first magnetic block 72 and the second magnetic block 74 + the elastic force of the spring 76, and the piston 73 is pushed down to Fig. 9 As shown in the state, the bottom of the piston 73 abuts against the lower abutment block 75, and the Y-type connecting cavity 731 is connected to the connecting hole 711. At this time, the condensed water accumulated at the bottom of the heat exchange pipe 20 is successively merged into the inner cavity of the water inlet pipe 50 through the Y-type connecting cavity 731 and the connecting hole 711, and finally merged into the circulating water, thereby realizing the automatic circulation function of the condensed water accumulated on the bottom wall of the heat exchange pipe 20, and avoiding the influence of the condensed water inside the heat exchange pipe 20 on the subsequent gas transportation.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. Ammonia synthesis reaction water circulation system, including a combustion furnace, a boiler, an acid making device and a water supply pump, characterized in that: The boiler comprises: A furnace body (10), the top of the furnace body (10) is integrally connected to a furnace top (11), the furnace top (11) is in a conical shape protruding outwards and the top of the conical shape is interconnected with a gas outlet main pipe (30), and the bottom of the furnace body (10) is provided with a water inlet pipe (50); A heat exchange pipe (20), the heat exchange pipe (20) being in the shape of a spring pipe and being horizontally placed in the inner cavity of the furnace body (10), an air outlet (21) being provided at the top of the end of the heat exchange pipe (20), the height of the air outlet (21) being higher than the drainage level of the furnace body (10) and the aperture of the air outlet (21) being smaller than the inner diameter of the heat exchange pipe (20); SO2 and hot steam generated after the combustion of the acidic gas in the combustion furnace enter the inner cavity of the furnace body (10) through the heat exchange pipe (20). The spring pipe-shaped heat exchange pipe (20) in the inner cavity of the furnace body (10) increases the heat exchange between the hot steam and the circulating water in the furnace body (10). After the heat exchange, the gas overflows upward from the gas outlet (21) and is finally transported to the acid-making device through the gas outlet main pipe (30).

2. The ammonia synthesis reaction water circulation system according to claim 1, characterized in that: A heat exchange component (60) is fixedly connected to the inner walls of the furnace body (10) and the furnace top (11), and the heat exchange component (60) comprises a bottom plate (63) fixedly connected to the inner wall of the furnace body (10), and a heat exchange plate (61) is fixedly connected to the top of the bottom plate (63), the heat exchange plate (61) is arc-shaped, and the arc-shaped inner concave surface of one of the heat exchange plates (61) is located above the air outlet (21).

3. The ammonia synthesis reaction water circulation system according to claim 2, characterized in that: Side plates (62) are integrally fixedly connected to both sides of the heat exchange plate (61), and the side plates (62) extend downward from the top of the heat exchange plate (61) along the curvature of the heat exchange plate (61).

4. The ammonia synthesis reaction water circulation system according to claim 1, characterized in that: A water outlet pipe (40) is interconnected on the side wall of the furnace body (10), and the water outlet pipe (40) and the drainage liquid level in the inner cavity of the furnace body (10) are flush.

5. The ammonia synthesis reaction water circulation system according to claim 1, characterized in that: A pressure-adaptive drainage mechanism (70) is provided at the bottom of the heat exchange pipe (20), and the pressure-adaptive drainage mechanism (70) extends to the inner cavity of the water inlet pipe (50).

6. The ammonia synthesis reaction water circulation system according to claim 5, characterized in that: The pressure-adaptive drainage mechanism (70) comprises a connecting pipe (71) interconnected with the bottom of the heat exchange pipe (20), and the bottom of the connecting pipe (71) is fixedly plugged into the water inlet pipe (50), a connecting hole (711) is provided on the side wall of the connecting pipe (71), and a pressure-adaptive drainage component is provided inside the connecting pipe (71).

7. The ammonia synthesis reaction water circulation system according to claim 6, characterized in that: The connecting pipe (71) is in the shape of a circular outer surface and a square inner surface, and the outer diameter of the connecting pipe (71) is smaller than the inner diameter of the water inlet pipe (50).

8. The ammonia synthesis reaction water circulation system according to claim 7, characterized in that: The pressure-following drainage component comprises a piston (73) in the inner cavity of a connecting pipe (71), a Y-shaped connecting cavity (731) is provided inside the piston (73), a first magnetic block (72) is fixedly connected to the inner wall of the connecting pipe (71), a second magnetic block (74) is embedded and fixedly connected to the top of the piston (73), and the second magnetic block (74) is directly opposite to the first magnetic block (72), and a spring (76) is fixedly connected between the piston (73) and the inner wall of the bottom of the connecting pipe (71).

9. The ammonia synthesis reaction water circulation system according to claim 8, characterized in that: A lower stop block (75) is fixedly connected to the inner wall of the communication pipe (71), and the lower stop block (75) is located below the communication hole (711).

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