A heat exchange device

Abstract

The present application relates to the technical fields of chemical energy saving and equipment corrosion prevention, and particularly relates to a heat exchange device, which comprises a triple heat exchanger, a steam pipeline connected to an inlet of a shell side of the triple heat exchanger, a tube-and-shell heat exchanger, and an ethylbenzene atomizer, wherein an outlet of a tube side of the triple heat exchanger is connected to an inlet of a tube side of the tube-and-shell heat exchanger, an outlet of the tube side of the tube-and-shell heat exchanger is connected to a circulating water cooling system, an inlet of the shell side of the tube-and-shell heat exchanger is connected to an ethylbenzene feeding pipeline, an outlet of the shell side of the tube-and-shell heat exchanger is connected to an ethylbenzene discharging pipeline, the other end of the ethylbenzene discharging pipeline is connected to the steam pipeline, and the other end of the ethylbenzene discharging pipeline is connected to the ethylbenzene atomizer, and the present application has the following beneficial effects: the problems of the triple heat exchanger inlet being prone to corrosion and the equipment being also subjected to cavitation corrosion in the prior art are solved, the steam and circulating water consumption is reduced, the comprehensive utilization efficiency of heat energy is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of energy conservation and corrosion prevention technology in chemical industry, and particularly to a heat exchange device. Background Technology

[0002] In the chemical production field, reducing energy costs and improving the corrosion resistance of equipment have always been key concerns and important means for enterprises to enhance their competitiveness. Affected by chemical reactions, mechanical wear, and external environmental factors, mechanical equipment will experience varying degrees of corrosion, shortening its service life and increasing operating costs. Therefore, improving the corrosion resistance of equipment has become one of the most pressing problems to be solved. Furthermore, how to efficiently utilize residual heat energy within the system to reduce energy consumption during operation also urgently needs to be addressed.

[0003] During the operation of the styrene plant, ethylbenzene, after being heated and vaporized by evaporating steam, is sent to the shell-side inlet of the triple heat exchanger. The shell-side inlet of the triple heat exchanger is subject to severe corrosion due to the scouring effect of ethylbenzene. This is mainly because incomplete vaporization of ethylbenzene leads to the formation of entrainment mist when steam and ethylbenzene enter the shell-side inlet of the triple heat exchanger. Furthermore, poor ethylbenzene vaporization can also cause cavitation corrosion of the equipment. Thirdly, the material at the tube-side outlet of the triple heat exchanger needs to be cooled with circulating water, resulting in a waste of the heat from the outlet material and a significant consumption of circulating water.

[0004] To address the issues of easy corrosion at the inlet of the triple heat exchanger and cavitation corrosion of the equipment, while reducing steam and circulating water consumption, improving the overall efficiency of thermal energy utilization, and lowering production costs, our company has proposed a heat exchange device. Summary of the Invention

[0005] The purpose of this invention is to provide a heat exchange device that solves the problems of easy corrosion at the inlet and cavitation corrosion of the equipment in the prior art of triple heat exchangers. At the same time, it has the characteristics of reducing steam and circulating water consumption, improving the comprehensive utilization efficiency of heat energy, and reducing production costs.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A heat exchange device includes a triple heat exchanger, wherein the shell-side inlet of the triple heat exchanger is connected to a steam pipeline, and the other end of the steam pipeline is connected to evaporating steam. The device also includes a shell-and-tube heat exchanger and an ethylbenzene atomizer. The tube-side outlet of the triple heat exchanger is connected to the tube-side inlet of the shell-and-tube heat exchanger, and the tube-side outlet of the shell-and-tube heat exchanger is connected to a circulating water cooling system. The shell-side inlet of the shell-and-tube heat exchanger is connected to an ethylbenzene feed pipeline, and the other end of the ethylbenzene feed pipeline is connected to ethylbenzene. The shell-side outlet of the shell-and-tube heat exchanger is connected to an ethylbenzene discharge pipeline, and the other end of the ethylbenzene discharge pipeline is connected to a steam pipeline and the other end of the ethylbenzene discharge pipeline is connected to the ethylbenzene atomizer. Temperature detector 1 and temperature detector 2 are respectively installed at the tube-side inlet and outlet of the shell-and-tube heat exchanger. A flow controller 1 and a flow regulating valve 1 are installed on the ethylene feed pipeline, and a flow controller 2 and a flow regulating valve 2 are installed on the steam pipeline.

[0007] Preferably, the triple heat exchanger has two shell-side inlets, and temperature detection machine three and temperature detector four are respectively installed at the two shell-side inlets. The steam pipeline includes a steam main and two steam branch pipes. One end of each of the two steam branch pipes is connected to the steam main, and the other end is connected to the two shell-side inlets of the triple heat exchanger. The ethylbenzene discharge pipeline is connected to the two steam branch pipes respectively. There are two ethylbenzene atomizers, which are located in the two steam branch pipes respectively. Each ethylbenzene atomizer includes a connecting flange, a guide pipe, and a mounting plate. Multiple spray bars are installed on the mounting plate, and multiple atomizing nozzles are installed on each spray bar.

[0008] Preferably, an anti-impact assembly is provided inside the triple heat exchanger near its shell-side inlet. The anti-impact assembly includes an anti-impact plate and an anti-impact tube. The anti-impact plate has a channel for ethylbenzene and steam to pass through. A Stellite alloy weld overlay layer with a thickness of 3 mm is provided on the side of the anti-impact plate facing the shell-side inlet of the triple heat exchanger.

[0009] As a preferred option, the temperature control range of the material outlet at the tube side of the triple heat exchanger is 125~127℃.

[0010] Preferably, the temperature range of the material discharged from the tube side of the shell-and-tube heat exchanger is 108~110℃.

[0011] As a preferred option, the flow rate of the ethylbenzene feed line is controlled within the range of 124~127 t / h.

[0012] Preferably, the flow rate of the steam feed for the steam pipeline is controlled within the range of 25~26 t / h.

[0013] Preferably, the temperature control range of the shell-side inlet feed of the triple heat exchanger is 103~105℃.

[0014] Preferably, the number of atomizing nozzles on the ethylbenzene atomizer is 40 to 50.

[0015] Preferably, there are 2 to 3 anti-impact plates, and the channels on adjacent anti-impact plates are staggered.

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. Before mixing ethylene and steam, the ethylene is preheated. When the ethylene is mixed with the steam, it is fully vaporized by the heat, which prevents mist entrainment when feeding into the shell-side inlet of the triple heat exchanger. This avoids the presence of both gas and liquid phases in the feed, thus preventing corrosion of the shell-side inlet of the triple heat exchanger due to ethylbenzene scouring. At the same time, this design also avoids secondary vaporization of ethylbenzene in the equipment, preventing cavitation corrosion caused by ethylbenzene vaporization in the equipment.

[0018] 2. By optimizing the ethylbenzene atomizer and rationally setting multiple atomizing nozzles, the ethylbenzene feed flow rate is guaranteed while ensuring that the ethylbenzene can be fully atomized. After the ethylbenzene is atomized into fine droplets, it helps to vaporize, thus enhancing the vaporization effect of ethylbenzene and effectively avoiding equipment corrosion caused by cavitation corrosion.

[0019] 3. By installing anti-impact components at the shell-side inlet of the triple heat exchanger, the anti-impact plates installed on the outside of the heat exchange tubes after the vaporized ethylbenzene enters the triple heat exchanger can effectively block the scouring of the feed material, preventing the mixture of ethylbenzene and steam from directly entering the interior of the triple heat exchanger and avoiding direct impact of the material on the heat exchange tubes. Therefore, the anti-erosion and corrosion performance of the triple heat exchanger is effectively enhanced, the service life of the equipment is extended, and the operating cost of the unit is reduced.

[0020] 4. By setting up a shell-and-tube heat exchanger, the tube-side discharge of the triple heat exchanger enters the tube-side of the shell-and-tube heat exchanger, while the ethylbenzene feed first passes through the shell-side of the shell-and-tube heat exchanger. After sufficient heat exchange between the two in the shell-and-tube heat exchanger, the temperature of the material at the tube-side outlet of the triple heat exchanger is reduced. In the subsequent circulating water cooling process, the amount of circulating water used is reduced. At the same time, the heat exchange process raises the temperature of ethylbenzene, which improves the ethylbenzene gasification effect while reducing the amount of heating steam used. Therefore, the beneficial effects of reducing energy consumption and saving costs are achieved. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of an embodiment;

[0022] Figure 2 This is a schematic diagram showing the connection relationship between the triple heat exchanger and the shell-and-tube heat exchanger in the embodiment;

[0023] Figure 3 This is a schematic diagram of the atomizing nozzle in the embodiment;

[0024] Figure 4 This is a top view of the anti-impact assembly of the triple heat exchanger in the embodiment;

[0025] Figure 5 This is a front view of the anti-impact plate in the embodiment.

[0026] In the diagram, 1. Triple heat exchanger; 11. Heat exchange tube; 2. Steam main; 21. Steam branch pipe; 22. Flow controller II; 23. Flow regulating valve II; 24. Temperature detector III; 25. Temperature detector IV; 3. Shell-and-tube heat exchanger; 31. Ethylbenzene feed line; 32. Ethylbenzene discharge line; 33. Temperature detector I; 34. Temperature detector II; 35. Flow controller I; 36. Flow regulating valve I; 41. Ethylbenzene atomizer I; 42. Ethylbenzene atomizer II; 43. Connecting flange; 44. Guide pipe; 45. Mounting plate; 46. Spray bar; 47. Atomizing nozzle; 5. Circulating water cooling system; 51. Dehydrogenation reactor; 61. Anti-impact plate; 62. Anti-impact pipe; 63. Channel; 64. Stellite alloy weld overlay. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings.

[0028] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0029] Example:

[0030] A heat exchange device

[0031] like Figure 1 and Figure 2 As shown, the system includes a triple heat exchanger 1, with its tube-side inlet at the top and its tube-side outlet at the bottom. The dehydrogenation product enters from the tube-side inlet of the triple heat exchanger 1 and exits from its tube-side outlet. Section E201 of the triple heat exchanger 1 has a shell-side inlet, and section E202 has a shell-side outlet. The shell-side inlet of the triple heat exchanger 1 is connected to a steam pipeline. A mixture of ethylbenzene and steam enters from the shell-side inlet of the triple heat exchanger 1 and exits from the shell-side outlet of the triple heat exchanger 1 to the dehydrogenation reactor 51. The triple heat exchanger 1 has two shell-side inlets, each equipped with a temperature detector 24 and a temperature detector 25. The steam pipeline includes a main steam pipe 2 and two branch steam pipes 21. One end of each branch steam pipe 21 is connected to one of the two shell-side inlets of the triple heat exchanger 1, and the other end is connected to the main steam pipe 2. Steam main 2 is connected to evaporated steam, and a flow controller 22 and a flow regulating valve 23 are installed on steam main 2.

[0032] A shell-and-tube heat exchanger 3 is installed at the tube-side outlet of the triple heat exchanger 1. The tube-side outlet of the triple heat exchanger 1 is connected to the tube-side inlet of the shell-and-tube heat exchanger 3, and the tube-side outlet of the shell-and-tube heat exchanger 3 is connected to the circulating water cooling system 5. Temperature detector 1 33 and temperature detector 2 34 are installed at the tube-side inlet and outlet of the shell-and-tube heat exchanger 3, respectively. An ethylbenzene feed line 31 is connected to the shell-side inlet of the shell-and-tube heat exchanger 3, and the other end of the ethylbenzene feed line 31 is connected to ethylbenzene. An ethylbenzene discharge line 32 is connected to the shell-and-tube outlet of the shell-and-tube heat exchanger 3, and the other end of the ethylbenzene discharge line 32 is connected to a steam line and an ethylbenzene atomizer. A flow controller 1 35 and a flow regulating valve 1 36 are installed on the ethylbenzene feed line 31. There are two ethylbenzene atomizers, namely ethylbenzene atomizer one 41 and ethylbenzene atomizer two 42, which are located in two steam branch pipes 21 respectively.

[0033] like Figure 3 As shown, the ethylbenzene atomizer includes a connecting flange 43, a guide pipe 44, and a mounting plate 45. Multiple spray bars 46 are mounted on the mounting plate 45, and each spray bar 46 is equipped with multiple atomizing nozzles 47. The guide pipe 44, mounting plate 45, and spray bars 46 are connected by pipes, allowing ethylbenzene to be sprayed from the atomizing nozzles 47.

[0034] like Figure 4 and Figure 5 As shown, the triple heat exchanger 1 contains heat exchange tubes 11. On both sides of the heat exchange tubes 11, near the shell-side inlet of the triple heat exchanger 1, anti-impact components are installed. Each anti-impact component includes an anti-impact plate 61 and an anti-impact tube 62. The anti-impact plate 61 is near the shell-side inlet of the triple heat exchanger 1, and the anti-impact tube 62 is near the heat exchange tubes 11. There are 2-3 anti-impact plates 61 on each side; in this embodiment, two anti-impact plates 61 are used, and adjacent anti-impact plates 61 are connected by a metal plate. Each anti-impact plate 61 has multiple vertically oriented channels 63 for ethylbenzene and vapor to pass through, and the channels 63 on adjacent anti-impact plates 61 are staggered. Each anti-impact plate 61 has a 3mm thick Stellite alloy weld overlay layer 64 on its side facing the shell-side inlet of the triple heat exchanger 1.

[0035] The temperature control range of the material outlet of the first tube side of the triple heat exchanger is 125~127℃.

[0036] The temperature control range of the material outlet of the three-tube pass of the shell-and-tube heat exchanger is 108~110℃.

[0037] The flow rate control range for the ethylbenzene feed line 31 is 124~127 t / h.

[0038] The flow rate control range for the steam feed in the steam pipeline is 25~26 t / h.

[0039] The temperature control range of the inlet feed for the shell side of the triple heat exchanger 1 is 103~105℃.

[0040] The number of atomizing nozzles 47 on the ethylbenzene atomizer is 40 to 50.

[0041] How to use:

[0042] The operation of this embodiment includes the following steps:

[0043] Step 1: The dehydrogenation product from the tube side outlet of the triple heat exchanger 1 is sent to the tube side of the shell-and-tube heat exchanger 3, and the feed ethylbenzene is sent to the shell side of the shell-and-tube heat exchanger 3. The cold ethylbenzene and the high-temperature dehydrogenation product exchange heat in the shell-and-tube heat exchanger 3. The ethylbenzene is heated and the dehydrogenation product is cooled. The feed ethylbenzene flow rate is controlled by the flow regulating valve 36.

[0044] Step 2: Based on Step 1, the cooled dehydrogenation product is further cooled by the circulating water cooling system 5 to form a dehydrogenation liquid. The heated ethylbenzene is atomized by ethylbenzene atomizer 41 and mixed with the evaporated steam for further vaporization. The flow rate of the evaporated steam is controlled by the flow regulating valve 23.

[0045] Step 3: Based on Step 2, the material after mixing ethylbenzene / vapor gasification is sent to the shell inlet of the triple heat exchanger 1 with anti-impact plate 61, and after exchanging heat with the tube material, it is sent to the dehydrogenation reactor 51.

[0046] Comparative example:

[0047] This comparative example uses a conventional method, including the following steps:

[0048] Step 1: The dehydrogenation products at the tube-side outlet of the triple heat exchanger are directly sent to the circulating water cooling system for cooling to produce dehydrogenation liquid;

[0049] Step 2: The unheated ethylbenzene feed is atomized by a common ethylbenzene atomizer and then sent to the steam system for further vaporization;

[0050] Step 3: The vaporized ethylbenzene / steam mixture is sent to the shell side of a triple heat exchanger without anti-impact plates, where it exchanges heat with the tube side material before being sent to the dehydrogenation reactor.

[0051] By statistically analyzing the circulating water and steam consumption data, and combining this with the equipment's operational status, the energy-saving and corrosion-resistant performance of the equipment was investigated, and the following data were obtained:

[0052]

[0053] Summary: Based on the above data, the heat exchange device designed in this embodiment significantly improves steam and circulating water consumption compared to the comparative example. Calculations show that the heat exchange device can save approximately 8.6 million yuan annually in energy costs related to steam and circulating water. Furthermore, inspection of the triple heat exchanger reveals that, compared to traditional triple heat exchange equipment, this invention exhibits superior resistance to erosion corrosion during styrene production.

Claims

1. A heat exchange device comprising a triple heat exchanger (1), characterized in that, The shell-side inlet of the triple heat exchanger (1) is connected to a steam line, the other end of which is connected to evaporating steam. It also includes a shell-and-tube heat exchanger (3) and an ethylbenzene atomizer. The tube-side outlet of the triple heat exchanger (1) is connected to the tube-side inlet of the shell-and-tube heat exchanger (3). The tube-side outlet of the shell-and-tube heat exchanger (3) is connected to a circulating water cooling system (5). The shell-side inlet of the shell-and-tube heat exchanger (3) is connected to an ethylbenzene feed line (31), the other end of which is connected to ethylbenzene. The shell-and-tube heat exchanger (3)... The shell-side outlet of the shell heat exchanger (3) is connected to an ethylbenzene discharge pipeline (32), the other end of which is connected to a steam pipeline and the other end of which is connected to an ethylbenzene atomizer. Temperature detector 1 (33) and temperature detector 2 (34) are respectively installed at the tube-side inlet and outlet of the shell-and-tube heat exchanger (3). Flow controller 1 (35) and flow regulating valve 1 (36) are installed on the ethylene feed pipeline, and flow controller 2 (22) and flow regulating valve 2 (23) are installed on the steam pipeline. The triple heat exchanger (1) has two shell-side inlets, and temperature detection machine three and temperature detector four (25) are respectively installed at the two shell-side inlets. The steam pipeline includes a steam main pipe (2) and two steam branch pipes (21). One end of each of the two steam branch pipes (21) is connected to the steam main pipe (2), and the other end is connected to the two shell-side inlets of the triple heat exchanger (1). The ethylbenzene discharge pipeline (32) is connected to the two steam branch pipes (21). There are two ethylbenzene atomizers. The two ethylbenzene atomizers are located in the two steam branch pipes (21). The ethylbenzene atomizer includes a connecting flange (43), a guide pipe (44), and a mounting plate (45). Multiple spray rods (46) are installed on the mounting plate (45), and multiple atomizing nozzles (47) are installed on each spray rod (46).

2. The heat exchange device according to claim 1, characterized in that, An anti-impact assembly is provided inside the triple heat exchanger (1) near its shell-side inlet. The anti-impact assembly includes an anti-impact plate (61) and an anti-impact tube (62). The anti-impact plate (61) has a channel (63) for ethylbenzene and steam to pass through. A Stellite alloy weld overlay layer (64) with a thickness of 3 mm is provided on the side of the anti-impact plate (61) facing the shell-side inlet of the triple heat exchanger (1).

3. The heat exchange device according to claim 1, characterized in that, The temperature control range of the tube side outlet of the triple heat exchanger (1) is 125~127℃.

4. The heat exchange device according to claim 1, characterized in that, The temperature control range of the material outlet of the shell-and-tube heat exchanger (3) is 108~110℃.

5. A heat exchange device according to claim 1, characterized in that, The flow rate control range of the ethylbenzene feed pipeline (31) is 124~127t / h.

6. A heat exchange device according to claim 1, characterized in that, The flow rate control range for the steam feed in the steam pipeline is 25~26 t / h.

7. A heat exchange device according to claim 1, characterized in that, The temperature control range of the shell-side inlet feed of the triple heat exchanger (1) is 103~105℃.

8. A heat exchange device according to claim 1, characterized in that, The number of atomizing nozzles (47) on the ethylbenzene atomizer is 40 to 50.

9. A heat exchange device according to claim 2, characterized in that, The number of anti-impact plates (61) is 2 to 3, and the channels (63) on two adjacent anti-impact plates (61) are staggered.

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