Cooling device for ammonia synthesis

Abstract

The application provides a cooling device for synthetic ammonia, which comprises an ammonia evaporation section and an ammonia drum section arranged above the ammonia evaporation section; the ammonia evaporation section comprises a first-stage ammonia cooler and a second-stage ammonia cooler arranged in series, a pipe passage gas inlet of the first-stage ammonia cooler is connected with a synthetic gas input pipeline, a pipe passage gas outlet of the first-stage ammonia cooler is connected with a pipe passage gas inlet of the second-stage ammonia cooler through a first pipeline, a pipe passage gas outlet of the second-stage ammonia cooler is connected with a synthetic ammonia gas output pipeline through a second pipeline, and a shell passage liquid ammonia inlet of the first-stage ammonia cooler and a shell passage liquid ammonia inlet of the second-stage ammonia cooler are respectively connected with a liquid ammonia pipeline; the ammonia drum section comprises a first ammonia drum and a second ammonia drum arranged in series, the first ammonia drum is arranged above the first-stage ammonia cooler correspondingly, the second ammonia drum is arranged above the second-stage ammonia cooler correspondingly, and the first-stage ammonia cooler and the first ammonia drum are connected with a first riser pipe and a first downcomer pipe, and the second-stage ammonia cooler and the second ammonia drum are connected with a second riser pipe and a second downcomer pipe. The device is stable in operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchangers, in particular to a cooling device for synthetic ammonia. BACKGROUND

[0002] Liquid ammonia is an important basic chemical raw material in China. When liquid ammonia is used as a raw material to produce nitric acid, the liquid ammonia needs to be heat exchanged. The existing heat exchange device has a small evaporation separation space and large gas-liquid phase disturbance during operation, which causes the problem of liquid ammonia being carried by gas ammonia during the intense evaporation process. The liquid carried by gas will cause the unit to frequently trip, and even damage the unit subsystem. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a cooling device for synthetic ammonia to solve the problems raised in the background art.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0005] The cooling device for synthetic ammonia comprises an ammonia evaporation section and an ammonia drum section arranged above the ammonia evaporation section, and the ammonia evaporation section is in communication with the ammonia drum section. The ammonia evaporation section comprises a first-stage ammonia cooler and a second-stage ammonia cooler arranged in series. The tube side gas inlet of the first-stage ammonia cooler is connected to a synthetic gas input pipeline. The tube side gas outlet of the first-stage ammonia cooler is connected to the tube side gas inlet of the second-stage ammonia cooler through a first pipeline. The tube side gas outlet of the second-stage ammonia cooler is connected to a synthetic ammonia gas output pipeline through a second pipeline. The liquid ammonia inlets in the shell side of the first-stage ammonia cooler and the second-stage ammonia cooler are respectively connected to a liquid ammonia pipeline.

[0006] The ammonia drum section comprises a first ammonia drum and a second ammonia drum arranged in series. The first ammonia drum is arranged above the first-stage ammonia cooler, and the second ammonia drum is arranged above the second-stage ammonia cooler. The first-stage ammonia cooler and the first ammonia drum are connected by a first riser and a first downcomer. The second-stage ammonia cooler and the second ammonia drum are connected by a second riser and a second downcomer.

[0007] Further, the liquid ammonia inlet of the first ammonia drum is connected to the liquid ammonia pipeline through a third pipeline, and the liquid ammonia outlet of the first ammonia drum is connected to the liquid ammonia inlet of the second ammonia drum through a fourth pipeline.

[0008] Further, a first liquid level regulating valve is arranged on the third pipeline, and a second liquid level regulating valve is arranged on the fourth pipeline.

[0009] Further, the first ammonia drum and the second ammonia drum are integrally arranged, and the first ammonia drum and the second ammonia drum are separated by a partition.

[0010] Further, the primary ammonia cooler and the secondary ammonia cooler share a shell, the evaporation chamber of the primary ammonia cooler and the evaporation chamber of the secondary ammonia cooler are located at two ends of the shell respectively, and the U-shaped heat exchange pipes of the primary ammonia cooler and the U-shaped heat exchange pipes of the secondary ammonia cooler are arranged in isolation.

[0011] Further, the tube side gas inlet of the primary ammonia cooler and the tube side gas outlet of the primary ammonia cooler are located at the upper part and the lower part of one end of the shell respectively, and the tube side gas inlet of the secondary ammonia cooler and the tube side gas outlet of the secondary ammonia cooler are located at the upper part and the lower part of the other end of the shell respectively.

[0012] Further, the first pipe at the tube side gas outlet of the primary ammonia cooler forms an angle of 30 degrees with the vertical line, the first pipe at the tube side gas inlet of the secondary ammonia cooler forms an angle of 7.8 degrees with the horizontal line, and the second pipe at the tube side gas outlet of the secondary ammonia cooler forms an angle of 30 degrees with the vertical line.

[0013] Further, the upper end of the first rising pipe is in communication with the side lower opening of the first ammonia drum, the lower end of the first rising pipe is in communication with the top opening of the shell side of the primary ammonia cooler, the upper end of the first falling pipe is in communication with the bottom opening of the first ammonia drum, the lower end of the first falling pipe is in communication with the bottom opening of the shell side of the primary ammonia cooler, the upper end of the second rising pipe is in communication with the side lower opening of the second ammonia drum, the lower end of the second rising pipe is in communication with the top opening of the shell side of the secondary ammonia cooler, the upper end of the second falling pipe is in communication with the bottom opening of the second ammonia drum, and the lower end of the second falling pipe is in communication with the bottom opening of the shell side of the secondary ammonia cooler.

[0014] Preferably, the axis corresponding to the side lower opening of the first ammonia drum forms an angle of 45 degrees with the vertical line, and the axis corresponding to the side lower opening of the second ammonia drum forms an angle of 45 degrees with the vertical line.

[0015] Further, the ammonia gas outlet of the first ammonia drum and the ammonia gas outlet of the second ammonia drum are connected with compressors respectively.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The application provides a cooling device for synthetic ammonia, which comprises an ammonia evaporation section and an ammonia drum section arranged above the ammonia evaporation section, wherein the ammonia evaporation section is communicated with the ammonia drum section; the ammonia evaporation section comprises a first-stage ammonia cooler and a second-stage ammonia cooler arranged in series, a pipe passage gas inlet of the first-stage ammonia cooler is communicated with a synthetic gas input pipeline, a pipe passage gas outlet of the first-stage ammonia cooler is communicated with a pipe passage gas inlet of the second-stage ammonia cooler through a first pipeline, a pipe passage gas outlet of the second-stage ammonia cooler is communicated with a synthetic ammonia gas output pipeline through a second pipeline, and a shell passage liquid ammonia inlet of the first-stage ammonia cooler and a shell passage liquid ammonia inlet of the second-stage ammonia cooler are respectively connected with a liquid ammonia pipeline; the ammonia drum section comprises a first ammonia drum and a second ammonia drum arranged in series, the first ammonia drum is arranged above the first-stage ammonia cooler, the second ammonia drum is arranged above the second-stage ammonia cooler, and a first riser and a first downcomer are connected between the first-stage ammonia cooler and the first ammonia drum, and a second riser and a second downcomer are connected between the second-stage ammonia cooler and the second ammonia drum. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the embodiment of the application.

[0019] In the figure: 1, first-stage ammonia cooler, 2, second-stage ammonia cooler, 3, synthetic gas input pipeline, 4, first pipeline, 5, second pipeline, 6, synthetic ammonia gas output pipeline, 7, liquid ammonia pipeline, 8, first ammonia drum, 9, second ammonia drum, 10, first riser, 11, first downcomer, 12, second riser, 13, second downcomer, 14, third pipeline, 15, fourth pipeline, 16, first liquid level adjusting valve, 17, second liquid level adjusting valve, 18, fifth pipeline, 19, sixth pipeline. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application.

[0021] Embodiment 1

[0022] As Figure 1As shown, the cooling device for synthetic ammonia is applied to the synthetic ammonia production, which comprises an ammonia evaporation section and an ammonia drum section arranged above the ammonia evaporation section, and the ammonia evaporation section is communicated with the ammonia drum section; specifically, the ammonia evaporation section comprises a first-stage ammonia cooler 1 and a second-stage ammonia cooler 2 arranged in series, a pipe passage gas inlet of the first-stage ammonia cooler 1 is communicated with a synthetic gas input pipeline 3, a pipe passage gas outlet of the first-stage ammonia cooler 1 is communicated with a pipe passage gas inlet of the second-stage ammonia cooler 2 through a first pipeline 4, and a pipe passage gas outlet of the second-stage ammonia cooler 2 is communicated with a synthetic ammonia gas output pipeline 6 through a second pipeline 5; a shell passage liquid ammonia inlets of the first-stage ammonia cooler 1 and the second-stage ammonia cooler 2 are respectively connected with liquid ammonia pipelines 7.

[0023] The first-stage ammonia cooler 1 and the second-stage ammonia cooler 2 of the embodiment share one shell, an evaporation chamber of the first-stage ammonia cooler 1 and an evaporation chamber of the second-stage ammonia cooler 2 are respectively located at two ends of the shell, and U-shaped heat exchange pipes of the first-stage ammonia cooler 1 and the second-stage ammonia cooler 2 are arranged in isolation through an isolation plate. It should be noted that the first-stage ammonia cooler 1 and the second-stage ammonia cooler 2 are integrally arranged, which can reduce the floor area, save the manufacturing cost of the equipment, and facilitate the flexible arrangement of the expansion project.

[0024] The pipe passage gas inlet of the first-stage ammonia cooler 1 and the pipe passage gas outlet of the first-stage ammonia cooler 1 are respectively located at the upper part and the lower part of one end of the shell, and the pipe passage gas inlet of the second-stage ammonia cooler 2 and the pipe passage gas outlet of the second-stage ammonia cooler 2 are respectively located at the upper part and the lower part of the other end of the shell.

[0025] The first pipeline 4 at the pipe passage gas outlet of the first-stage ammonia cooler 1 has an angle of 30 degrees with the vertical line, the first pipeline 4 at the pipe passage gas inlet of the second-stage ammonia cooler 2 has an angle of 7.8 degrees with the horizontal line, and the second pipeline 5 at the pipe passage gas outlet of the second-stage ammonia cooler 2 has an angle of 30 degrees with the vertical line. It should be noted that the different inclination angles of the two ends of the first pipeline 4 in the above structure avoid the liquid impact condition that may occur in the gas-liquid two-phase flow in the pipeline.

[0026] The ammonia drum section comprises first and second ammonia drums 8 and 9 arranged in series, the first and second ammonia drums 8 and 9 of the embodiment are integrally arranged, and the first ammonia drum 8 is isolated from the second ammonia drum 9 by a partition plate. It should be noted that the integral arrangement of the first and second ammonia drums 8 and 9 reduces the floor area of the device, is particularly suitable for expansion projects, increases the separation space, and reduces the risk of gas ammonia carrying liquid.

[0027] The first ammonia vapor pocket 8 is arranged above the first ammonia cooler 1, the second ammonia vapor pocket 9 is arranged above the second ammonia cooler 2, the first rising pipe 10 and the first falling pipe 11 are connected between the first ammonia cooler 1 and the first ammonia vapor pocket 8, and the second rising pipe 12 and the second falling pipe 13 are connected between the second ammonia cooler 2 and the second ammonia vapor pocket 9. Specifically, the upper end of the first rising pipe 10 is communicated with the lower side opening of the first ammonia vapor pocket 8, the lower end of the first rising pipe 10 is communicated with the top opening of the shell side of the first ammonia cooler 1, the upper end of the first falling pipe 11 is communicated with the bottom opening of the first ammonia vapor pocket 8, the lower end of the first falling pipe 11 is communicated with the bottom opening of the shell side of the first ammonia cooler 1, and preferably, the included angle between the axis corresponding to the lower side opening of the first ammonia vapor pocket 8 and the vertical line is 45°. The upper end of the second rising pipe 12 is communicated with the lower side opening of the second ammonia vapor pocket 9, the lower end of the second rising pipe 12 is communicated with the top opening of the shell side of the second ammonia cooler 2, the upper end of the second falling pipe 13 is communicated with the bottom opening of the second ammonia vapor pocket 9, the lower end of the second falling pipe 13 is communicated with the bottom opening of the shell side of the second ammonia cooler 2, and preferably, the included angle between the axis corresponding to the lower side opening of the second ammonia vapor pocket 9 and the vertical line is 45°.

[0028] The liquid ammonia inlet of the first ammonia vapor pocket 8 is connected with the liquid ammonia pipeline 7 through the third pipeline 14, the liquid ammonia outlet of the first ammonia vapor pocket 8 is connected with the liquid ammonia inlet of the second ammonia vapor pocket 9 through the fourth pipeline 15, and the ammonia gas outlets of the first ammonia vapor pocket 8 and the second ammonia vapor pocket 9 are respectively connected with the compressor through the fifth pipeline 18 and the sixth pipeline 19.

[0029] In order to facilitate the adjustment and control of the liquid level of the first ammonia vapor pocket 8, the first liquid level adjusting valve 16 is arranged on the third pipeline 14, and in order to facilitate the adjustment and control of the liquid level of the second ammonia vapor pocket 9, the second liquid level adjusting valve 17 is arranged on the fourth pipeline 15.

[0030] In use, the synthesis gas in the synthesis gas input pipeline 3 from the front equipment is 27.5℃, the synthesis gas is input from the top of the evaporation chamber of the first ammonia cooler 1, after heat exchange in the U-shaped heat exchange pipe, the temperature of the synthesis gas is reduced to 12℃ after deviating from the vertical line by an angle of 30° on the same side. In the process of the cooled synthesis gas going to the ammonia evaporation chamber of the second ammonia cooler 2, a pipeline with an upward angle of about 7.8° is formed by using a 60° short radius elbow and a 90° elbow to enter the ammonia evaporation chamber of the second ammonia cooler 2, which solves the liquid impact condition that may occur in the gas-liquid two-phase flow in the pipeline. The temperature of the synthesis gas out of the ammonia evaporation chamber of the second ammonia cooler 2 is -10℃, and the synthesis gas is sent to the high-pressure ammonia storage through the synthesis ammonia gas output pipeline 6 after deviating from the vertical line by an angle of 30°.

[0031] The shell side of the ammonia evaporation section is liquid ammonia, and when the hot process gas (synthesis gas) flows through the heat exchange pipe, the liquid ammonia is heated, and the heat absorbed by the liquid ammonia is taken away by the vaporization of the liquid ammonia through the rising pipe into the ammonia vapor tank. The liquid ammonia that has not evaporated reenters the ammonia evaporation section through the descending pipe. The first ammonia vapor tank 8 and the second ammonia vapor tank 9 are separated by a partition plate into two evaporation spaces. The first ammonia vapor tank 8 corresponds to the evaporation chamber side of the first ammonia cooler 1, and the second ammonia vapor tank 9 corresponds to the ammonia evaporation chamber side of the second ammonia cooler 2, and different evaporation pressures are controlled respectively. The liquid ammonia from the ammonia receiving tank enters the first ammonia vapor tank 8 through the first liquid level regulating valve 16, and the first ammonia vapor tank 8 is controlled at a normal liquid level. The fourth pipeline 15 is led out from the bottom of the first ammonia vapor tank 8, and the second liquid level regulating valve 17 controls the second ammonia vapor tank 9 at a normal liquid level.

[0032] The beneficial effects of the embodiment compared with the prior art are:

[0033] The ammonia cooling device for synthesis ammonia in the embodiment avoids the liquid in the ammonia gas entering the ammonia ice machine system due to the small liquid-vapor evaporation space of the traditional first and second ammonia coolers and the incomplete gas-liquid separation, thereby interlocking the ammonia ice machine to trip, and the ammonia ice machine compressor system is seriously damaged. In the construction process, the construction cost of civil engineering and equipment can be significantly reduced, and the land occupation of equipment can be reduced in the plant that replaces the old and new production capacity.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0035] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0036] In the present application, unless specifically defined otherwise, the terms "mount", "set", "connect", "connect", "fix", "screw" and the like are to be construed in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate media, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly contacted through intermediate media. Moreover, the first feature "on", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] It should be noted that when an element is referred to as "fixed to" or "set to" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only implementation.

[0039] In the description of the present application, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0040] The above has shown and described the embodiments of the present application, and those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. Cooling device for the synthesis of ammonia, characterized in that: The ammonia evaporation section and the ammonia drum section arranged above the ammonia evaporation section are communicated; the ammonia evaporation section comprises a primary ammonia cooler and a secondary ammonia cooler arranged in series, a tube side gas inlet of the primary ammonia cooler is communicated with a syngas input pipeline, a tube side gas outlet of the primary ammonia cooler is communicated with a tube side gas inlet of the secondary ammonia cooler through a first pipeline, a tube side gas outlet of the secondary ammonia cooler is communicated with a syngas output pipeline through a second pipeline, and a shell side liquid ammonia inlet of the primary ammonia cooler and a shell side liquid ammonia inlet of the secondary ammonia cooler are respectively connected with a liquid ammonia pipeline; The ammonia drum section comprises a first ammonia drum and a second ammonia drum arranged in series, the first ammonia drum is arranged above the primary ammonia cooler, the second ammonia drum is arranged above the secondary ammonia cooler, and a first riser and a first downcomer are connected between the primary ammonia cooler and the first ammonia drum, and a second riser and a second downcomer are connected between the secondary ammonia cooler and the second ammonia drum; A liquid ammonia inlet of the first ammonia drum is connected with the liquid ammonia pipeline through a third pipeline, and a liquid ammonia outlet of the first ammonia drum is connected with a liquid ammonia inlet of the second ammonia drum through a fourth pipeline; The first ammonia drum and the second ammonia drum are integrally arranged, and the first ammonia drum and the second ammonia drum are isolated by a partition plate; The primary ammonia cooler and the secondary ammonia cooler share a shell, and an evaporation chamber of the primary ammonia cooler and an evaporation chamber of the secondary ammonia cooler are respectively located at two ends of the shell, and U-shaped heat exchange pipes of the primary ammonia cooler and U-shaped heat exchange pipes of the secondary ammonia cooler are arranged in isolation; A tube side gas inlet of the primary ammonia cooler and a tube side gas outlet of the primary ammonia cooler are respectively located at an upper portion and a lower portion of one end of the shell, and a tube side gas inlet of the secondary ammonia cooler and a tube side gas outlet of the secondary ammonia cooler are respectively located at an upper portion and a lower portion of the other end of the shell; An included angle between the first pipeline at the tube side gas outlet of the primary ammonia cooler and a vertical line is 30 degrees, an included angle between the first pipeline at the tube side gas inlet of the secondary ammonia cooler and a horizontal line is 7.8 degrees, and an included angle between the second pipeline at the tube side gas outlet of the secondary ammonia cooler and a vertical line is 30 degrees; An ammonia gas outlet of the first ammonia drum and an ammonia gas outlet of the second ammonia drum are respectively connected with a compressor.

2. The cooling device for synthetic ammonia according to claim 1, characterized by: A first liquid level adjusting valve is arranged on the third pipeline, and a second liquid level adjusting valve is arranged on the fourth pipeline.

3. The cooling device for synthetic ammonia according to claim 1, characterized by: An upper end of the first riser is communicated with a side lower portion opening of the first ammonia drum, a lower end of the first riser is communicated with a top opening of a shell side of the primary ammonia cooler, an upper end of the first downcomer is communicated with a bottom opening of the first ammonia drum, a lower end of the first downcomer is communicated with a bottom opening of the shell side of the primary ammonia cooler, an upper end of the second riser is communicated with a side lower portion opening of the second ammonia drum, a lower end of the second riser is communicated with a top opening of a shell side of the secondary ammonia cooler, an upper end of the second downcomer is communicated with a bottom opening of the second ammonia drum, and a lower end of the second downcomer is communicated with a bottom opening of the shell side of the secondary ammonia cooler.

4. The cooling device for synthetic ammonia according to claim 3, characterized by: The included angle between the axis corresponding to the side lower opening of the first ammonia vapor pocket and the vertical line is 45°, and the included angle between the axis corresponding to the side lower opening of the second ammonia vapor pocket and the vertical line is 45°.

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