Circulation gas thermolator

Abstract

The invention discloses a novel circulating gas thermolator and a manufacturing method thereof, and belongs to the technical field of chemical equipment. The equipment is structurally innovated aiming at the problems that the welding part of the outlet of the lower tube box and the lower sealing head of the traditional circulating gas thermolator is undetectable and easy to crack. The main improvement is as follows: an internally-closed elliptical manhole is formed in the center of a lower sealing head of the cylinder body; an original single central large outlet is changed into a plurality of evenly-distributed outlet short pipes, and the outlet short pipes are in sliding and flexible connection with a stuffing box connecting assembly fixed to a lower sealing head through expansion joints. By means of the structure, double-face welding and RT detection of all key weld joints can be achieved, and the manufacturing quality is greatly guaranteed; meanwhile, the stress state of the structure is remarkably improved through multi-path load distribution and flexible connection design, stress concentration and fatigue risks are reduced, and therefore long-period safe and stable operation of equipment under the high-temperature and high-pressure load working conditions is achieved.

Description

Technical Field

[0001] This invention relates to the field of large-scale chemical equipment technology, specifically to a circulating gas temperature control device for coal chemical, methanol synthesis and other plants, and in particular to a novel circulating gas temperature control structure that can significantly improve long-term operational reliability and is easy to manufacture and test. Background Technology

[0002] Currently, large-scale coal chemical enterprises in China are promoting the transformation of coal from "fuel" to "raw material" through technological innovation, industrial upgrading, and green transformation. To achieve the "dual carbon" goals and energy security, they have invested in multiple demonstration projects for clean and efficient coal-to-olefins, aromatics, and deep processing engineering. Through the system integration of coal pyrolysis, coal / semi-coke gasification, and downstream deep processing technologies, they are further expanding and extending the industrial chain, exploring new paths for the coupled development of coal-based olefins and coal-based aromatics, and producing four major categories of high-value-added products: high-performance materials, battery electrolyte solvents, biodegradable materials, and specialty oils, in order to achieve the high-end, diversified, and low-carbon development of the coal chemical industry.

[0003] The circulating gas temperature controller is a key piece of equipment in the gasification and methanol synthesis unit. By adjusting the circulating gas temperature, it achieves precise control of the catalyst bed temperature in methanol synthesis, ensuring that the methanol synthesis reaction proceeds within the optimal temperature range. During the methanol synthesis reaction, as the temperature increases, the equilibrium shifts towards the reverse reaction, leading to a decrease in methanol yield. Furthermore, while higher temperatures accelerate the reaction rate, excessively high temperatures can cause catalyst (copper-based) sintering and deactivation, promoting the formation of byproducts such as paraffin and carbonyl compounds, and reducing methanol selectivity. Therefore, the long-term stable operation of the circulating gas temperature controller is crucial.

[0004] The circulating gas thermostat operates under extremely harsh conditions, with the circulating gas side working pressure exceeding 8 MPa. This high pressure, high temperature, and large temperature differential load result in a structurally robust design. The upper tube sheet is fixed, while the lower tube sheet slides freely within the shell. An expansion joint is installed at the lower tube box outlet and welded to the lower end cap of the shell to absorb the thermal expansion difference between the tube and shell sides, as well as the deflection displacement of the lower tube box caused by airflow impact. The weld between the lower end of the expansion joint at the central outlet of the lower tube box and the lower end cap of the shell is subject to complex stresses, allowing only single-sided welding and making RT testing impossible. When internal defects exist in this weld, penetrating cracks and fractures can easily occur, directly causing the entire equipment or even the entire system to shut down, resulting in significant economic losses.

[0005] Therefore, developing a new type of circulating gas temperature regulator that can fundamentally solve the reliability problems of the above-mentioned connection parts, achieve easy high-quality manufacturing and non-destructive testing, has a reasonable structural stress, and can adapt to long-term harsh working conditions has become an urgent technical need in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned deficiencies of the prior art and provide a circulating gas temperature regulator with a novel structure, high reliability, and long service life. This device, through an innovative connection structure between the lower tube box outlet and the lower end cap of the cylinder, ensures the inspectability, manufacturability, and mechanical reliability of key connection parts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A circulating gas temperature regulator includes a cylinder (9), a tube bundle (12), an upper tube sheet (13), a lower tube sheet (11), a syngas inlet pipe (15), a circulating gas outlet pipe (16), a circulating gas inlet pipe (17), a lower end cap (7), an upper tube box (14), and a lower tube box (10). A syngas inlet pipe (15) is installed at the upper end of the top end cap of the upper tube box. The upper tube sheet (13) is fixedly installed at the lower end of the upper tube box (14). The upper tube sheet (13) is fixedly connected to the upper end of the cylinder (9). The lower tube box (10) is fixedly installed with the lower tube sheet (11) at its upper end. The cylinder (9) contains a tube bundle (12), the upper end of which penetrates the upper tube sheet (13) and... The tube bundle (12) is sealed and fixed on the upper tube sheet (13). The lower end of the tube bundle (12) passes through the lower tube sheet (11) and is sealed and fixed below the lower tube sheet (11). The lower tube box (10) and the lower tube sheet (11) are slidably sealed inside the cylinder (9). A circulating gas outlet pipe (16) is installed on the outer side of the cylinder (9) near the upper end and is located below the upper tube sheet (13). A circulating gas inlet pipe (17) is installed on the outer side of the cylinder (9) near the lower end and is located above the lower tube sheet. A lower end cap (7) is also installed at the bottom of the cylinder (9), and the lower tube box (10) is located above the lower end cap (7). A skirt seat (1) is also provided at the lower end of the lower end cap (7). The lower end cap (7) has an inner closed elliptical manhole (18) at its center; a plurality of stuffing box connection assemblies are arranged around the inner closed elliptical manhole (18) on the lower end cap (7); the bottom of the lower pipe box (10) is provided with a plurality of outlet short pipes (19) corresponding to the number of stuffing box connection assemblies, and an expansion joint (8) is installed near the middle position of each outlet short pipe (19). The lower section of the outlet short pipe (19) is sealed to the upper end of the corresponding stuffing box connection assembly and can be slidably connected.

[0008] The number of stuffing gland connection components is multiple, and they are radially evenly distributed around the inner closed elliptical manhole (18).

[0009] The stuffing box connection assembly includes a stuffing box seat (3), sealing packing (4), and a stuffing gland (5) fixed on the lower end cap (7). The lower end of the outlet short pipe (19) slides in the inner cavity of the stuffing box seat (3), and the stuffing box seat (3) and the lower end of the outlet short pipe (19) are filled with sealing packing (4), which is then pressed and sealed by the stuffing gland (5). The stuffing gland (5) is fixed to the upper end of the stuffing box seat (3) by bolts (6), and the lower end of the stuffing gland (5) presses down on the sealing packing (4). The upper end of the stuffing box seat (3) has an annular groove for filling with sealing packing.

[0010] The stuffing box seat (3) passes through the lower end cap (7) and is welded to it; the lower end of the stuffing box seat (3) is provided with a syngas outlet pipe (2), which is bent and passes through the skirt seat (1).

[0011] The internally closed elliptical manhole (18) adopts a self-tightening sealing structure.

[0012] The expansion joint (8) is a metal bellows expansion joint.

[0013] The beneficial effects of this invention are as follows: 1. Revolutionary inspectability and manufacturability: By opening an internally closed elliptical manhole (18) at the center of the lower head, operators can enter the equipment to perform double-sided welding on the butt ring welds at the upper and lower ends of the expansion joint (8) and conduct 100% radiographic testing (RT). At the same time, the welded joint of the stuffing box seat (3) penetrating the lower head (7) can also be welded and RT inspected from both inside and outside the equipment. This fundamentally eliminates the quality risks of "blind welding" and "blind inspection" of traditional structural welds, ensuring manufacturing quality.

[0014] 2. Superior structural mechanical performance: By changing the single concentrated load path (one large central outlet) to multiple evenly distributed load paths (multiple small outlets), stress concentration at individual connection points is significantly reduced. Simultaneously, the rigid welded connection is replaced with a stuffing box connection that allows axial sliding, enabling the structure to effectively absorb thermal displacement and deflection loads, greatly reducing stress concentration at connection points and improving equipment safety and service life.

[0015] 3. Significantly improved operational reliability and economy: The above two improvements directly translate into an ultra-long fault-free operating cycle of the equipment, greatly reducing the risk of unplanned downtime caused by the failure of key equipment, providing key equipment guarantee for the "safe, stable, long-term, full-capacity and high-quality" operation of the entire chemical plant, with significant economic and safety benefits. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of the overall structure of the novel circulating gas temperature regulator of the present invention.

[0017] Figure 2 This is a partially enlarged detailed view of the connection structure between the outlet of the lower tube box and the lower end cap of the cylinder in this invention. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto. Example

[0019] See Figures 1 to 2 The novel circulating gas temperature regulator provided by this invention has a vertical shell-and-tube structure as its main body. The cylinder (9) is provided with tube bundles (12), the process circulating gas flows through the shell side, and the synthesis gas flows through the tube side. The upper tube sheet (13) is fixed to the cylinder (9), and the lower tube sheet (11) can slide freely inside the cylinder (9) to compensate for temperature difference expansion.

[0020] The core improvement of this invention lies in the connection area between the lower tube box (10) and the lower end cap (7) of the cylinder. The specific structure is as follows: An internally closed elliptical manhole (18) is provided at the center of the lower end cap (7). The manhole is a high-pressure resistant self-tightening sealing door that ensures sealing during equipment operation and can be opened for personnel to enter during maintenance.

[0021] Multiple stuffing box seats (3) are radially and evenly distributed around the central manhole (18). The stuffing box seats (3) penetrate the lower head (7) and are fixedly connected to the lower head (7) by a fully penetrated welded structure. The weld bevel can be processed and welded from both the inside and outside of the equipment, and RT testing can be easily performed after welding to ensure the quality of this critical pressure-bearing connection. The lower end of the stuffing box seat (3) extends to form (or connects to) the syngas outlet pipe (2), which is bent and penetrates the skirt seat (1).

[0022] The bottom of the lower tube box (10) is provided with a number of outlet short pipes (19). Each outlet short pipe (19) is equipped with an expansion joint (8) near the middle position. The lower section of the outlet short pipe (19) is sealed and slidably connected to the upper end of the corresponding stuffing box connection assembly. The lower section of the outlet short pipe (19) slides into the stuffing box seat (3), and high temperature and high pressure resistant sealing packing (4) is filled between the stuffing box seat (3) and the lower section of the outlet short pipe (19), and the sealing packing (4) is pressed by the stuffing gland (5). The large central outlet of the lower tube box is changed to multiple smaller outlets evenly distributed. The welding of the lower end of the expansion joint of the outlet to the lower end of the cylinder head is changed to a stuffing box connection, allowing the lower section of the outlet short pipe (19) to slide up and down in the stuffing box seat (3). Multiple thick-walled stuffing box seats (3) and the lower end (7) adopt a through-type fully welded connection structure, forming a solid support that is sufficient to withstand the deflection displacement load of the lower tube box (10) caused by airflow impact.

[0023] Manufacturing and assembly process: The cylinder (9) (with lower end cap (7)), the lower tube box (10), and the connecting assembly containing multiple stuffing box seats (3) are manufactured separately. The lower tube box (10) is hoisted into place so that its multiple outlet short pipes (19) are aligned with the multiple stuffing box seats (3).

[0024] Enter the equipment through the central manhole (18). Inside the equipment, the expansion joint (8) and the outlet short pipe (19) can be installed conveniently. First, insert the lower section of the outlet short pipe (19) into the stuffing box seat (3). Before insertion, the stuffing cap (5) should be placed on the outside of the lower section of the outlet short pipe (19). Then, the upper end of the expansion joint (8) is installed below the upper section of the outlet short pipe (19) by means of flange bolt connection or welding. Then, the lower section of the outlet short pipe (19) is lifted out of the stuffing box seat (3). The upper part of the lower section of the outlet short pipe (19) is connected to the lower end of the expansion joint (8) in the same way. Then fill the sealing packing (4) into the annular groove of the stuffing box seat (3), and fix the packing gland (5) to the upper end of the stuffing box seat (3) with bolts (6), so that the lower end of the packing gland (5) presses down on the sealing packing (4), so that the sealing packing (4) is squeezed and expanded to achieve sealing; the circumferential weld is welded, and high-quality RT testing can be performed after welding.

Claims

1. A circulating gas temperature regulator, comprising a cylinder (9), a tube bundle (12), an upper tube sheet (13), a lower tube sheet (11), a syngas inlet pipe (15), a circulating gas outlet pipe (16), a circulating gas inlet pipe (17), a lower end cap (7), an upper tube box (14), and a lower tube box (10). The upper end of the top end cap of the upper tube box (14) is equipped with a syngas inlet pipe (15), and the lower end of the upper tube box (14) is fixedly equipped with an upper tube sheet (13). The upper tube sheet (13) is fixedly connected to the upper end of the cylinder (9), and the lower end of the lower tube box (10) is fixedly equipped with a lower tube sheet (11). The cylinder (9) is internally designed with a tube bundle (12), and the upper end of the tube bundle (12) penetrates the upper tube sheet (17). 3) The tube bundle (12) is sealed and fixed on the upper tube sheet (13), and the lower end of the tube bundle (12) passes through the lower tube sheet (11) and is sealed and fixed below the lower tube sheet (11). The lower tube box (10) and the lower tube sheet (11) are slidably sealed inside the cylinder (9). A circulating gas outlet pipe (16) is installed on the outer side of the cylinder (9) near the upper end and the circulating gas outlet pipe (16) is located below the upper tube sheet (13). A circulating gas inlet pipe (17) is installed on the outer side of the cylinder (9) near the lower end and the circulating gas inlet pipe (17) is located above the lower tube sheet. A lower end cap (7) is also installed at the bottom of the cylinder (9), and the lower tube box (10) is located above the lower end cap (7). A skirt seat (1) is also provided at the lower end of the lower end cap (7). Its features are, The lower end cap (7) has an inner closed elliptical manhole (18) at its center; a plurality of stuffing box connection assemblies are arranged around the inner closed elliptical manhole (18) on the lower end cap (7); the bottom of the lower pipe box (10) is provided with a plurality of outlet short pipes (19) corresponding to the number of stuffing box connection assemblies, and an expansion joint (8) is installed near the middle position of each outlet short pipe (19). The lower section of the outlet short pipe (19) is sealed to the upper end of the corresponding stuffing box connection assembly and can be slidably connected.

2. The circulating gas temperature regulator according to claim 1, characterized in that, The number of stuffing gland connection components is multiple, and they are radially evenly distributed around the inner closed elliptical manhole (18).

3. The circulating gas temperature regulator according to claim 1 or 2, characterized in that, The stuffing box connection assembly includes a stuffing box seat (3), sealing packing (4), and a stuffing gland (5) fixed on the lower end cap (7). The lower end of the outlet short pipe (19) slides in the inner cavity of the stuffing box seat (3), and the stuffing box seat (3) and the lower end of the outlet short pipe (19) are filled with sealing packing (4), which is then pressed and sealed by the stuffing gland (5). The stuffing gland (5) is fixed to the upper end of the stuffing box seat (3) by bolts (6), and the lower end of the stuffing gland (5) presses down on the sealing packing (4). The upper end of the stuffing box seat (3) has an annular groove for filling with sealing packing.

4. The circulating gas temperature regulator according to claim 3, characterized in that, The stuffing box seat (3) passes through the lower end cap (7) and is welded to it; the lower end of the stuffing box seat (3) is provided with a syngas outlet pipe (2), which is bent and passes through the skirt seat (1).

5. The circulating gas temperature regulator according to claim 1, characterized in that, The internally closed elliptical manhole (18) adopts a self-tightening sealing structure.

6. The circulating gas temperature regulator according to claim 1, characterized in that, The expansion joint (8) is a metal bellows expansion joint.

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