A heat recovery system for hot high pressure gas in a hydrogenation unit

Abstract

A heat recovery system for hot high-pressure separation gas in a hydrogenation device, comprising a first heat exchanger with first cold and hot medium channels, a second heat exchanger with second cold and hot medium channels, a third heat exchanger with third cold and hot medium channels, and an air cooler, wherein the first cold medium channel has a first cold medium inlet for hydrogen gas or a mixture of raw oil and hydrogen gas and a first cold medium outlet; the second cold medium channel has a second cold medium inlet for low-pressure separation oil or stripper bottom liquid and a second cold medium outlet; the third cold medium channel has a third cold medium inlet for water and a third cold medium outlet; the first, second and third hot medium channels are connected in sequence, the inlet of the air cooler is connected with the third hot medium outlet of the third heat exchanger, and the outlet is connected with the inlet of a cold high-pressure separation tank of the hydrogenation device. Compared with the prior art, the heat of the hot high-pressure separation gas can be further utilized, and the heat dissipation requirement of the air cooler is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of heat exchange, and particularly relates to a heat recovery system for hot high-pressure separation gas in a hydrogenation device. BACKGROUND

[0002] The existing hydrogenation device, such as the invention patent application for 'Hydrogenation heat exchange system and heat exchange process using multi-stream winding pipe heat exchanger' (application publication number CN113063309A) with application number CN202110477804.0 and the invention patent application for 'Hydrogenation heat exchange system and heat exchange process using multi-stream winding pipe heat exchanger' (application publication number CN113091498A) with application number CN202110477849.8, generally exchanges heat between the hot high-pressure separation gas output from a hot high-pressure separation tank and the mixture of low-pressure separation oil, raw oil and hydrogen gas, and then inputs the hot high-pressure separation gas into an air cooler for heat dissipation and cooling. In the traditional process flow, the hot high-pressure separation gas after heat exchange often needs a large number of air coolers to meet the process heat dissipation requirements, which increases the equipment investment, steel consumption and energy consumption of the air coolers in the running process, and increases the leakage risk of the air coolers; meanwhile, it also causes the waste loss of part of the heat in the hot high-pressure separation gas.

[0003] Meanwhile, the air coolers are generally divided into dry-type air coolers and wet-type air coolers according to different cooling methods. The dry-type air cooler relies on continuous air supply by a fan to realize cooling, and has the defects of large resistance drop, large equipment size, the need for multiple parallel operations, and thus occupies a large space. Meanwhile, the heat exchange effect of the dry-type air cooler is not ideal, the consumption of metal and other energy is large, and the pipe arrangement is complex. The wet-type air cooler strengthens heat exchange by means of spraying or atomization of cooling liquid (generally water), and the heat exchange effect is better than that of the dry-type air cooler. However, the wet-type air cooler is limited in pressure and large-scale application, and it is difficult to apply in the high-pressure field such as hydrogenation and hydrocracking. In addition, the hot high-pressure separation gas has a certain corrosiveness, and in order to prevent ammonium salt corrosion in the wet-type air cooler, a nickel-based alloy material with high price is usually used, which has high cost. Meanwhile, the wet-type air cooler sprays water from the top, and has the problems of uneven water spraying, large water spraying amount and no effective full evaporation of the heat exchange pipes, which leads to low heat exchange efficiency and large water consumption. SUMMARY

[0004] The first technical problem to be solved by the present application is to provide a heat recovery system for hot high-pressure separation gas in a hydrogenation device to further utilize the heat of the hot high-pressure separation gas, so as to reduce the heat dissipation requirements of the air cooler.

[0005] The second technical problem to be solved by the present application is to provide a heat recovery system for hot high-pressure separation gas in a hydrogenation device to reduce the risk of leakage.

[0006] The third technical problem to be solved by the present application is to provide a heat recovery system for hot high-pressure separated gas in a hydrogenation device to improve the heat exchange effect of an air cooler.

[0007] The technical scheme adopted by the present application to solve the first technical problem is a heat recovery system for hot high-pressure separated gas in a hydrogenation device, characterized in that it comprises:

[0008] a first heat exchanger having a first hot medium channel and a first cold medium channel, the first hot medium channel having a first hot medium inlet for input of hot high-pressure separated gas output by a hot high-pressure separation tank of the hydrogenation device and a first hot medium outlet for output of heat-exchanged hot high-pressure separated gas, and the first cold medium channel having a first cold medium inlet for input of hydrogen gas or a mixture of raw oil and hydrogen gas and a first cold medium outlet for output of heat-exchanged hydrogen gas or mixture;

[0009] a second heat exchanger having a second hot medium channel and a second cold medium channel, the second hot medium channel having a second hot medium inlet and a second hot medium outlet, the second hot medium inlet being in communication with the first hot medium outlet of the first heat exchanger, and the second cold medium channel having a second cold medium inlet for input of low-pressure separated oil or stripper column bottom liquid and a second cold medium outlet for output of heat-exchanged low-pressure separated oil or stripper column bottom liquid;

[0010] a third heat exchanger having a third hot medium channel and a third cold medium channel, the third hot medium channel having a third hot medium inlet and a third hot medium outlet, the third hot medium inlet being in communication with the second hot medium outlet of the second heat exchanger, and the third cold medium channel having a third cold medium inlet for input of water and a third cold medium outlet for output of heat-exchanged water;

[0011] an air cooler, the inlet of which being in communication with the third hot medium outlet of the third heat exchanger, and the outlet of which being used for connection to the inlet of a cold high-pressure separation tank of the hydrogenation device.

[0012] The "hydrogen gas" in the present application can be recycled hydrogen (which may carry impurities) output from the hydrogenation device, or hydrogen gas directly accessed from the outside.

[0013] In the above scheme, the water entering the third cold medium inlet of the third heat exchanger can be low-pressure water or high-pressure water. To further solve the second technical problem, preferably, the third cold medium inlet of the third heat exchanger is connected with a high-pressure water pipeline for conveying high-pressure water, and the third hot medium outlet of the third heat exchanger is in communication with the inlet of the air cooler through a third pipeline.

[0014] The fourth heat exchanger has a fourth hot medium channel and a fourth cold medium channel, the fourth hot medium channel has a fourth hot medium inlet and a fourth hot medium outlet, the fourth hot medium inlet is communicated with the third cold medium outlet of the third heat exchanger, and the fourth hot medium outlet is communicated with the third pipeline; the fourth cold medium channel has a fourth cold medium inlet for input of low-pressure water and a fourth cold medium outlet for output of the low-pressure water after heat exchange. In this way, the high-pressure water exchanges heat with the hot high-pressure gas in the third hot medium channel to balance the pressure in the third heat exchanger, thereby reducing the risk of water pollution caused by pressure imbalance and leakage of the hot high-pressure gas into the water. The fourth heat exchanger is arranged to heat the low-pressure water, and the heated low-pressure water can be used for household heating and the like; and even if the high-pressure water leaks into the low-pressure water, there is no pollution problem because the media of the two are consistent, both being water.

[0015] Preferably, the second hot medium outlet of the second heat exchanger is communicated with the third hot medium inlet of the third heat exchanger through a second pipeline, and the second pipeline is communicated with the high-pressure water pipeline through a first bypass pipeline.

[0016] Preferably, the second hot medium outlet of the second heat exchanger is communicated with the third hot medium inlet of the third heat exchanger through a second pipeline, the fourth hot medium outlet of the fourth heat exchanger is communicated with the third pipeline through a fourth pipeline, and the fourth pipeline is communicated with the second pipeline through a second bypass pipeline.

[0017] In the above scheme, each heat exchanger can be a common shell-and-tube heat exchanger. Preferably, the first, second, third and fourth heat exchangers are all coiled tube heat exchangers, and the tube side of the first, second and third heat exchangers is the hot medium channel, and the shell side is the cold medium channel; the tube side of the fourth heat exchanger is the fourth cold medium channel, and the shell side is the fourth hot medium channel.

[0018] Preferably, the first, second and third heat exchangers are combined into a multi-stream coiled tube heat exchanger having one tube side and three shell sides, the first hot medium channel of the first heat exchanger, the second hot medium channel of the second heat exchanger and the third hot medium channel of the third heat exchanger are sequentially communicated and serve as the tube side of the multi-stream coiled tube heat exchanger, the first hot medium inlet of the first hot medium channel serves as the tube side inlet, and the third hot medium outlet of the third hot medium channel serves as the tube side outlet.

[0019] The three shell passes of the multi-strand flow wound pipe heat exchanger are respectively referred to as a first shell pass, a second shell pass and a third shell pass, the first cold medium passage of the first heat exchanger is taken as the first shell pass of the multi-strand flow wound pipe heat exchanger, the second cold medium passage of the second heat exchanger is taken as the second shell pass of the multi-strand flow wound pipe heat exchanger, and the third cold medium passage of the third heat exchanger is taken as the third shell pass of the multi-strand flow wound pipe heat exchanger, and the first shell pass, the second shell pass and the third shell pass are arranged in sequence along the direction from the tube pass inlet to the tube pass outlet.

[0020] Preferably, the fourth heat exchanger is a single-strand flow wound pipe heat exchanger with a single tube pass and a single shell pass, the single tube pass is the hot medium passage mentioned above, and the single shell pass is the cold medium passage mentioned above.

[0021] Preferably, the first hot medium outlet of the first heat exchanger is connected to the second hot medium inlet of the second heat exchanger through a first pipeline, and a first water injection pipeline is connected to the first pipeline.

[0022] The first hot medium inlet of the first heat exchanger is connected to a hot high-temperature separation gas pipeline for conveying hot high-temperature separation gas, and a second water injection pipeline is connected to the hot high-temperature separation gas pipeline.

[0023] To further solve the third technical problem mentioned above, preferably, the air cooler comprises:

[0024] A shell pass cylinder is vertically arranged, and two ends thereof are respectively provided with an air inlet and an air outlet;

[0025] Two tube sheets are arranged on the side walls of the shell pass cylinder in an upper and lower manner;

[0026] Two tube boxes are arranged on the respective tube sheets;

[0027] A central cylinder is vertically arranged in the shell pass cylinder;

[0028] A plurality of heat exchange pipes are arranged in the shell pass cylinder in an axial manner, and are spirally wound on the outer periphery of the central cylinder to form a plurality of layers of spiral pipes, and two ends of the heat exchange pipes are respectively supported on the respective tube sheets and connected to the respective tube boxes;

[0029] A plurality of spray pipes are arranged in the shell pass cylinder in an axial manner, and are wound in the respective layers of spiral pipes along the spiral direction of the heat exchange pipes, the pipe openings of the lower ends of the respective spray pipes are liquid inlets, the pipe openings of the upper ends of the respective spray pipes are downwardly open liquid outlets, the liquid outlets are arranged above the spiral pipes along the circumferential direction of the shell pass cylinder, and the liquid outlets are arranged in a spaced manner; meanwhile, a plurality of spray holes are arranged on the pipe walls of the respective spray pipes, and the spray holes are opposite to the pipe walls of the adjacent heat exchange pipes.

[0030] Thus, when the air cooler works, the inside of the spray pipe is filled with cooling liquid, the cooling liquid enters the spray pipe from the liquid inlet, part of the cooling liquid is sprayed to the adjacent heat exchange pipe through the spray hole, and part of the cooling liquid is sprayed downward from the liquid outlet, so that the heat exchange of the high-temperature heat medium in the heat exchange pipe is realized, and the circumferentially spaced liquid outlets can ensure uniform water spraying and stable water spraying amount, thereby effectively improving the heat exchange efficiency.

[0031] Preferably, the nozzle at the upper end of each spray pipe is connected with a spray head capable of spraying water downward.

[0032] In the above scheme, preferably, the bottom of the shell side cylinder body is provided with a water collecting tank, and the liquid inlet of the spray pipe is connected in communication with the water collecting tank through a water pump.

[0033] Further, the air inlet is located at the lower end of the shell side cylinder body, and the air outlet is located at the upper end of the shell side cylinder body.

[0034] In order to improve the utilization rate of water in the water collecting tank, preferably, a water collector is further included, which is arranged in the shell side cylinder body and above the liquid outlet of the spray pipe, and the water collector has a passage through which the airflow passes upward and can collect water in the airflow. In this way, the consumption of water can be reduced.

[0035] More preferably, the water collector includes a plurality of vertically arranged and connected water collecting plates, and the plurality of water collecting plates are arranged in the horizontal direction and spaced apart, and the passage is formed between the plate surfaces of the adjacent two water collecting plates. Meanwhile, the plate surface of each water collecting plate is provided with an upwardly extending lip, and the lip and the plate surface of the water collecting plate form a water collecting groove with an upward opening and used for collecting water stored on the plate surface above the lip.

[0036] In order to better recover the water in the water collecting groove, further, the water collector further includes a water collecting groove located in the center of the water collector and extending through the water collecting plates along the arrangement direction of the water collecting plates;

[0037] The water collector is sleeved on the outer periphery of the above-mentioned central cylinder, and the water collecting groove is provided for the central cylinder to pass through, the inside of the central cylinder is hollow, and the lower end thereof is connected in communication with the above-mentioned water collecting tank, and the cylinder wall opposite to the water collecting groove of the central cylinder is provided with a water inlet connected in communication with the water collecting groove.

[0038] In order to ensure the gas-water separation effect while not affecting the heat exchange of the air cooler, preferably, the spacing distance between the adjacent two water collecting plates is 20-50 mm.

[0039] In order to better collect the water in the water collecting groove, preferably, the water collector comprises a plurality of vertically arranged and connected water collecting plates, the plurality of water collecting plates are arranged in a circumferential direction at the periphery of the central cylinder, the plate surfaces of two adjacent water collecting plates form the channel, the plate surface of each water collecting plate is provided with an upwardly extending lip, the lip and the plate surface of the water collecting plate form a water collecting groove which is upwardly open and used for collecting water in the airflow, each water collecting groove extends from the outside to the inside of the plate surface of the water collecting plate to the central cylinder, the inside of the central cylinder is hollow, and the lower end of the central cylinder is connected with the water collecting tank, and the cylinder wall opposite to the water collector is provided with a water inlet which is connected with the water collecting groove.

[0040] In order to facilitate the water in the water collecting groove to flow to the water collecting tank, preferably, the water collecting groove is inclined downwardly from the outside to the inside.

[0041] In order to improve the gas-water separation effect and better collect water, preferably, each water collecting plate is formed in a wave shape from top to bottom, at least one water collecting groove is arranged on the same side plate surface of each water collecting plate, and each water collecting groove is located at the outward protruding position of the plate surface of each water collecting plate.

[0042] In the above schemes, the heat exchange pipe can be a smooth pipe, in order to improve the heat exchange effect, preferably, the heat exchange pipe is a corrugated pipe, and has a smooth pipe section with a smooth surface and a corrugated section with corrugated surface, the corrugated section and the smooth pipe section are alternately arranged along the length direction of the heat exchange pipe, and the length of the corrugated section is greater than the length of the smooth pipe section.

[0043] Or, the heat exchange pipe is a finned tube, and has a smooth pipe section with a smooth surface and a finned section with fins, the finned section and the smooth pipe section are alternately arranged along the length direction of the heat exchange pipe, and the length of the finned section is greater than the length of the smooth pipe section.

[0044] Preferably, the above two tube plates and two tube boxes form a group, there are at least two groups and they are arranged in a circumferential direction of the shell side cylinder body. Of course, there can be only one group, and the number of groups is designed according to the number of heat exchange pipes.

[0045] Compared with the prior art, the advantages of the present application are that: by arranging the first heat exchanger, the second heat exchanger, the third heat exchanger and the air cooler, the hot high-pressure separated gas output from the hot high-pressure separation tank is sequentially heat-exchanged with hydrogen or mixed material in the first heat exchanger, low-pressure separated oil or stripping column bottom liquid in the second heat exchanger, and water in the third heat exchanger, and then enters the air cooler for further cooling, so that the temperature of the hot high-pressure separated gas before entering the air cooler is lower, thereby reducing the heat dissipation requirement of the air cooler; and the arrangement of the third heat exchanger in the present application can further utilize the heat of the hot high-pressure separated gas to heat water, and the heated water can be used for residential heating.

[0046] The heat exchange sequence in the application is as follows: the hot high separation gas exchanges heat with hydrogen or mixed materials first, then exchanges heat with low separation oil or stripping tower bottom liquid, and finally exchanges heat with water. The heat exchange sequence has the following effects:

[0047] 1. The high-temperature hot high separation gas is used to preferentially increase the temperature of hydrogen or mixed materials, which helps to increase the temperature of the mixed feed; 2. The low separation oil or stripping tower bottom liquid has a lower temperature than hydrogen or mixed materials, and heat exchange after hydrogen or mixed materials is beneficial to the hierarchical use of heat; 3. Water is used as a coolant for heat recovery, and the outlet temperature of water is determined according to the temperature of the hot high separation gas, which can further reduce the temperature of the hot high separation gas. In summary, the above heat exchange sequence realizes the step-by-step use of the temperature level of the heat source, effectively uses the heat of the hot high separation gas to heat the materials, and reduces the area of the heat exchange equipment, thereby reducing the investment in the heat exchange equipment. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 Figure 1 is a structural schematic diagram of an embodiment of the application;

[0049] Figure 2 Figure 2 is a structural schematic diagram of another embodiment of the application;

[0050] Figure 3 Figure 3 is a structural schematic diagram of a third embodiment of the application;

[0051] Figure 4 Figure 4 is a partial structural schematic diagram of a fourth embodiment of the application (only the content of the dashed box is shown); Figure 1

[0052] Figure 5 Figure 5 is a structural schematic diagram of the air cooler in the fourth embodiment of the application;

[0053] Figure 6 Figure 6 is a structural schematic diagram of the heat exchange tube and the spray pipe in the fourth embodiment of the application (the cross-sectional area is the water spraying area); Figure 5

[0054] Figure 7 is a cross-sectional view of A-A in the fourth embodiment of the application; Figure 7 Figure 5 Figure 8 is a structural schematic diagram of the water collector and the center tube in the fourth embodiment of the application;

[0055] Figure 8 Figure 5 Figure 9 is a top view of the fourth embodiment of the application;

[0056] Figure 9 Figure 10 is a partial structural schematic diagram of the center tube in the fourth embodiment of the application; Figure 8

[0057] Figure 10 Figure 5

[0058] Figure 11 Figure 9 ​​​​​​​Schematic diagram of the structure in direction B;

[0059] Figure 12 for Figure 5 A partial structural diagram of the heat exchanger tube;

[0060] Figure 13 This is a top view of the water collector and the central cylinder of the air cooler in Embodiment 5 of the present invention.

[0061] Figure 14 This is a partial structural diagram of Embodiment Six of the present invention;

[0062] Figure 15 This is a partial structural diagram of Embodiment Seven of the present invention. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0064] Example 1:

[0065] like Figure 1 As shown, this is a preferred embodiment of a heat recovery system for hot high-temperature gas in a hydrogenation unit according to the present invention. The heat recovery system includes a first heat exchanger 100, a second heat exchanger 200, a third heat exchanger 300, and an air cooler 400.

[0066] The first heat exchanger 100 is a single-flow wound tube heat exchanger with one shell side and one tube side, and has a first hot medium channel 110 (tube side) and a first cold medium channel 120 (shell side). The first hot medium channel 110 has a first hot medium inlet 111 for inputting hot high-pressure gas from the hot high-pressure separator of the hydrogenation unit and a first hot medium outlet 112 for outputting the hot high-pressure gas after heat exchange. The first hot medium inlet 111 is connected to a hot high-pressure gas pipeline 150 for conveying the hot high-pressure gas, and a second water injection pipeline 160 is connected to the hot high-pressure gas pipeline 150. The first cold medium channel 120 has a first cold medium inlet 121 for inputting a mixture of feedstock oil and hydrogen and a first cold medium outlet 122 for outputting the mixture after heat exchange.

[0067] The second heat exchanger 200 is a single flow winding pipe heat exchanger with one shell side and one tube side, and has a second heat medium passage 210 (as the tube side) and a second cold medium passage 220 (as the shell side). The second heat medium passage 210 has a second heat medium inlet 211 and a second heat medium outlet 212, and the second heat medium inlet 211 is connected to the first heat medium outlet 112 of the first heat exchanger 100 through the first pipeline 130. The second cold medium passage 220 has a second cold medium inlet 221 for the low fraction oil or the stripped tower bottom liquid to enter and a second cold medium outlet 222 for the low fraction oil or the stripped tower bottom liquid after heat exchange to be output.

[0068] The third heat exchanger 300 is a single flow winding pipe heat exchanger with one shell side and one tube side, and has a third heat medium passage 310 (as the tube side) and a third cold medium passage 320 (as the shell side). The third heat medium passage 310 has a third heat medium inlet 311 and a third heat medium outlet 312, and the third heat medium inlet 311 is connected to the second heat medium outlet 212 of the second heat exchanger 200 through the second pipeline 230. The third cold medium passage 320 has a third cold medium inlet 321 for water to enter and a third cold medium outlet 322 for the water after heat exchange to be output.

[0069] The air cooler 400 is of a conventional structure, and its inlet is connected to the third heat medium outlet 312 of the third heat exchanger 300 through the third pipeline 340. The third pipeline 340 is connected to the fourth water injection pipeline 350.

[0070] The heat recovery system of the embodiment is used in a hydrogenation device, which has a hot high-pressure separation tank 700, a hot low-pressure separation tank 710, a cold high-pressure separation tank 720 and a cold low-pressure separation tank 730. The top outlet of the hot high-pressure separation tank 700 is connected to the first heat medium inlet 111 of the first heat exchanger 100 through the hot high-pressure gas pipeline 150. The bottom outlet of the hot high-pressure separation tank 700 is connected to the inlet of the hot low-pressure separation tank 710 through a pipeline (with a pressure reducing device). The top outlet of the hot low-pressure separation tank 710 is connected to the inlet of the cold low-pressure separation tank 730 through a pipeline (with a low-temperature water heat exchanger and a hot low-pressure gas air cooler). The inlet of the cold high-pressure separation tank 720 is connected to the outlet of the air cooler 400 in the heat recovery system, and the bottom outlet of the cold high-pressure separation tank 720 is connected to the inlet of the cold low-pressure separation tank 730 through a pipeline (with a pressure reducing device).

[0071] The hydrogenation process of the embodiment is as follows:

[0072] The hydrogenation reaction effluent, after being cooled by heat exchange, enters the hot high-pressure separator 700. The gas phase (hot high-pressure gas) is drawn from the top outlet of the hot high-pressure separator 700, and successively exchanges heat with the mixture of feedstock oil and hydrogen, cold low-pressure oil or stripping tower bottom liquid, then passes through low-temperature hot water for heat removal, and finally enters the air cooler 400 for cooling, before entering the cold high-pressure separator 720. The gas in the cold high-pressure separator 720 is drawn from the top outlet of the cold high-pressure separator 720 as circulating gas (hydrogen), which is pressurized by a compressor, heated by a heat exchanger, and then enters the reaction system to participate in the reaction. The bottom liquid in the cold high-pressure separator 720 is depressurized and enters the cold low-pressure separator 730. Hot high-pressure oil is drawn from the bottom outlet of hot high-pressure separator 700, and after being depressurized by hot high-pressure liquid turbine, it enters hot low-pressure separator 710. Hot low-pressure gas is drawn from the top outlet of hot low-pressure separator 710, and after being heated by low-temperature water, it enters hot low-pressure gas air cooler for cooling, and then enters cold low-pressure separator 730. The liquid phase at the bottom of cold low-pressure separator 730 enters the separation section (main stripping tower) for further separation and purification. For details, please refer to the prior art, which will not be elaborated here.

[0073] Example 2:

[0074] like Figure 2 As shown, this is a preferred embodiment of the heat recovery system for hot high-pressure gas in a hydrogenation unit according to the present invention. This embodiment is basically the same as the first embodiment, except that the third cold medium inlet 321 of the third heat exchanger 300 in this embodiment is connected to a high-pressure water pipeline 330 for conveying high-pressure water. The high-pressure water pipeline 330 is connected to the second pipeline 230 mentioned above through a first bypass pipeline 240. The system also includes a fourth heat exchanger 500, which is a wound-tube heat exchanger with one shell side and one tube side. It has a fourth hot medium channel 510 (shell side) and a fourth cold medium channel 520 (tube side). The fourth hot medium channel 510 has a fourth hot medium inlet 511 and a fourth hot medium outlet 512. The fourth hot medium inlet 511 is connected to the third cold medium outlet 322 of the aforementioned third heat exchanger. The fourth hot medium outlet 512 is connected to the aforementioned third pipeline 340 via a fourth pipeline 530. The fourth cold medium channel 520 has a fourth cold medium inlet 521 for low-pressure water input and a fourth cold medium outlet 522 for low-pressure water output after heat exchange. Thus, in this embodiment, high-pressure water and hot high-pressure gas are first used for heat exchange. Both the high-pressure water and the hot high-pressure gas are under high pressure, which keeps the pressure within the third heat exchanger 300 balanced, reducing the risk of water contamination due to leakage of the tube-side medium within the third heat exchanger 300. Furthermore, the high-pressure water and low-pressure water exchange heat in the fourth heat exchanger 500 after heat exchange, thereby heating the low-pressure water. The low-pressure water can be used for residential water supply and heating. Even if there is a leak in the medium inside the fourth heat exchanger 500, since it is all water, there is no pollution problem.

[0075] Meanwhile, due to the presence of the first bypass pipeline 240 and the fourth pipeline 530, this embodiment does not require the additional installation of the third water injection pipeline 250 and the fourth water injection pipeline 350.

[0076] Example 3:

[0077] like Figure 3 As shown, this is a preferred embodiment three of the heat recovery system for hot high-temperature gas in a hydrogenation unit according to the present invention. This embodiment is basically the same as embodiment two, except that in this embodiment, there is no need to set up the first bypass pipeline 240, and the fourth pipeline 530 and the second pipeline 230 are connected through the second bypass pipeline 540.

[0078] Example 4:

[0079] like Figures 4-12 The image shows a preferred embodiment four of the heat recovery system for hot high-temperature gas in a hydrogenation unit according to the present invention. This embodiment is basically the same as the first embodiment, except that the first, second, and third heat exchangers are combined into a multi-flow wound tube heat exchanger with one tube side and three shell sides. The first heat medium channel 110 of the first heat exchanger 100, the second heat medium channel 210 of the second heat exchanger 200, and the third heat medium channel 310 of the third heat exchanger 300 are sequentially connected and serve as the tube side of the multi-flow wound tube heat exchanger. The first heat medium inlet 111 of the first heat medium channel 110 serves as the tube side inlet, and the third heat medium outlet 312 of the third heat medium channel 310 serves as the tube side outlet.

[0080] The three shells of the multi-flow wound tube heat exchanger are respectively designated as the first shell, the second shell, and the third shell. The first cold medium channel 120 of the first heat exchanger 100 serves as the first shell of the multi-flow wound tube heat exchanger, the second cold medium channel 220 of the second heat exchanger 200 serves as the second shell of the multi-flow wound tube heat exchanger, and the third cold medium channel 320 of the third heat exchanger 300 serves as the third shell of the multi-flow wound tube heat exchanger. The first shell, the second shell, and the third shell are arranged sequentially from the tube inlet to the tube outlet.

[0081] At the same time, such as Figures 5-12 As shown, the air cooler in this embodiment is a wound tube composite air cooler, which includes a shell-side cylinder 1, two tube sheets, two tube boxes 2, a central cylinder 3, multiple heat exchange tubes 4, multiple spray tubes 5, a water collection tank 6, a water pump 7, and a water collector 8.

[0082] The shell-side cylinder 1 is vertically arranged, with an air inlet 11 at its lower end and an air outlet 12 at its upper end. A fan is installed at the air outlet 12 to allow airflow to enter the shell-side cylinder 1 from the air inlet 11 and then exit from the air outlet 12. A water collection tank 6 is provided at the bottom of the shell-side cylinder 1.

[0083] Two tube plates are arranged on the side wall of the shell side cylinder 1 respectively from top to bottom; two tube boxes 2 are arranged on the corresponding tube plates respectively.

[0084] The central cylinder 3 is vertically arranged in the shell side cylinder 1. The inside of the central cylinder 3 is hollow, and the lower end 31 extends into the water collecting box 6.

[0085] A plurality of heat exchange pipes 4 are arranged in the shell side cylinder 1 along the axial direction, and are spirally wound on the outer periphery of the central cylinder 3 to form a plurality of layers of spiral pipes. The spacing between adjacent layers of spiral pipes is not less than 4 mm. The two ends of the heat exchange pipes 4 are respectively supported on the corresponding tube plates and are in communication with the corresponding tube boxes 2. In this embodiment, the heat exchange pipes 4 are corrugated pipes, and have smooth pipe sections 41 with smooth surfaces and corrugated sections 42 with corrugated surfaces. The corrugated sections 42 and the smooth pipe sections 41 are alternately arranged along the length direction of the heat exchange pipes 4, and the length of the corrugated sections 42 is greater than the length of the smooth pipe sections 41. Specifically, the length of the corrugated sections 42 is 200 mm, and the length of the smooth pipe sections 41 is 50 mm. The smooth pipe sections 41 are used to cooperate with fixing members (such as gasket strips for heat exchangers) to fix the heat exchange pipes.

[0086] A plurality of spray pipes 5 are arranged in the shell side cylinder 1 along the axial direction, and are wound in the spiral direction of the heat exchange pipes 4 in each layer of spiral pipes (at least one spray pipe 5 is arranged in each layer of spiral pipes, and the spray pipe 5 is wound synchronously with the plurality of heat exchange pipes 4 in the layer, please refer to Figure 2 ). The lower end of each spray pipe 5 is provided with an inlet port 51, and is in communication with the water collecting box 6 through the water pump 7. The upper end of each spray pipe 5 is provided with an outlet port 52 with the opening facing downward, and the outlet port 52 is located above the spiral pipe and is arranged equidistantly along the circumferential direction of the shell side cylinder 1. In order to make the water flow sprayed by each outlet port 52 more uniform, further, the upper end of each spray pipe 5 is connected with a spray head 54 capable of spraying water downward. In this embodiment, the three spray heads 54 are distributed in the three end points of an equilateral triangle between adjacent three spray heads 54, so as to ensure that the spraying radius of each spray head 54 is not less than 150 mm. A plurality of spray holes 53 are arranged on the wall of each spray pipe 5, and the spray holes 53 are opposite to the wall of the adjacent heat exchange pipe 4 to spray the adjacent heat exchange pipe. Please refer to Figure 2 . Specifically, the plurality of layers of spiral pipes are sequentially recorded as the first layer, the second layer, …, and the Nth layer from inside to outside. The plurality of spray holes of the spray pipe in the first layer are respectively directed to the upper surfaces of the heat exchange pipes in the second layer and the heat exchange pipes arranged adjacent to each other in the first layer (located below the spray pipe in the first layer). The plurality of spray holes of the spray pipe in the Nth layer are respectively directed to the upper surfaces of the heat exchange pipes in the N-1th layer and the heat exchange pipes arranged adjacent to each other in the Nth layer (located below the spray pipe in the Nth layer). The plurality of spray holes of the spray pipe in the intermediate layer between the first layer and the Nth layer are respectively directed to the upper surfaces of the heat exchange pipes arranged adjacent to each other in the same layer and the adjacent layer.

[0087] The water collector 8 is arranged in the shell side cylinder 1 above the liquid outlet 52 of the spray pipe 5, and has a passage 80 for the gas flow to pass upward and collect the water in the gas flow. In this embodiment, the water collector 8 is sleeved on the outer periphery of the central cylinder 3, and includes a plurality of vertically arranged and connected water collecting plates 81. The water collecting plates 81 can be connected by upper and lower base plates (the upper and lower base plates can be made in a grid shape or a plate with holes), or connected by connecting rods, each of which passes through each water collecting plate 81 to connect the water collecting plates 81. The water collecting plates 81 are arranged in the horizontal direction with a spacing, preferably, the spacing between two adjacent water collecting plates is 20-50 mm (the spacing can be 20 mm, 50 mm or any value between them), which can ensure the gas-water separation effect and not affect the heat exchange of the air cooler, so that the passage 80 is formed between the surfaces of two adjacent water collecting plates 81. Meanwhile, the surface of each water collecting plate 81 is provided with an upwardly extending lip 811, and the lip 811 and the surface of the water collecting plate 81 form a water collecting groove 82 for collecting the water accumulated on the surface above the lip 811. Please refer to Figure 5 、 7 ( Figure 5 The water collecting plates 81 are represented by a plurality of base lines a, and the number of the base lines a is not limited to the number shown in the figure. The installation position and arrangement direction of the water collecting plates 81 are represented by the base lines a. In this embodiment, the water collector 8 further includes a water collecting groove 83 located in the center of the water collector 8 and extending along the arrangement direction of the water collecting plates 81 and penetrating the water collecting plates 81. The water collecting groove 83 has a bottom plate and side plates on both sides of the bottom plate, and the bottom plate and the two side plates form a U-shaped water collecting groove 83. The water collecting groove 82 extends from the outside to the inside of the surface of the water collecting plate 81 to the water collecting groove 83 and communicates with the water collecting groove 83, and the water collecting groove 82 is inclined downward from the outside to the inside, so that the water in the water collecting groove 82 can flow into the water collecting groove 83 under the action of its own gravity. The central cylinder 3 penetrates the water collecting groove 83, and the cylinder wall opposite to the water collecting groove 83 is provided with a water inlet 32 which communicates with the water collecting groove 83. In this way, the water collected in the water collecting groove 82 can enter the central cylinder 3 through the water collecting groove 83 and the water inlet 32, and then flow back to the water collecting tank 6, thereby realizing the reuse of the cooling water.

[0088] In this embodiment, in order to have a better water collecting effect, each water collecting plate 81 is made in a wavy structure from top to bottom, please refer to Figure 7 . One or more water collecting grooves 82 can be designed on the same side surface of each water collecting plate 81 as needed, and each water collecting groove 82 is located at the outer protruding part of the surface of each water collecting plate 81, so that the water vapor accumulated on the surface of each water collecting plate 81 can be completely collected by the water collecting groove 82 when flowing downward.

[0089] Embodiment five:

[0090] As Figure 13 shown, it is a preferred embodiment five of the heat recovery system for hot high pressure gas in a hydrogenation device of the present application, this embodiment is basically the same as embodiment four, the difference is that the structure of the water collector 8 of the air cooler 400 in this embodiment is slightly different, as follows: the water collector 8 of this embodiment includes a plurality of vertically arranged and connected water collecting plates 81, a plurality of water collecting plates 81 are arranged in the periphery of the center cylinder 3 in a circumferential direction, the plate surface of the adjacent two water collecting plates 81 forms a channel 80 for the gas flow upward, and the plate surface of each water collecting plate 81 is provided with an upward extending lip 811, the lip 811 and the plate surface of the water collecting plate 81 form a water collecting groove 82 with the opening upward and used for collecting the water on the plate surface above the lip 811, each water collecting groove 82 extends from the outside to the inside of the plate surface of the water collecting plate 81 to the center cylinder 3, and the water collecting groove 82 is inclined downward from the outside to the inside. The inside of the center cylinder 3 is hollow, and its lower port 31 is connected with the water collector 6, and the water inlet 32 is arranged on the cylinder wall opposite to the water collector 8, which is connected with the water collecting groove 82.

[0091] In this way, when the gas flow passes through the channel 80 upward, the water in the gas flow will accumulate on the plate surface of the water collecting plate 81, and flow downward along the plate surface of the water collecting plate 81 into the water collecting groove 82, the water in the water collecting groove 82 flows along the water collecting groove 82 to the water inlet 32 of the center cylinder 3 under the action of gravity, and then flows back to the water collector 6 through the center cylinder 3, realizing the recycling of water.

[0092] Embodiment six:

[0093] As Figure 14The image shows a preferred embodiment six of the heat recovery system for hot high-pressure gas in a hydrogenation unit according to the present invention. This embodiment is basically the same as embodiment four, except that the third cold medium inlet 321 of the third shell side in this embodiment is connected to a high-pressure water pipeline 330 for conveying high-pressure water. The high-pressure water pipeline 330 is connected to the connecting pipe on the multi-flow wound tube heat exchanger through a first bypass pipeline 240. This connecting pipe is connected to the part of the tube side of the multi-flow wound tube heat exchanger located between the second and third shell sides. It also includes a fourth heat exchanger 500, which is a wound tube heat exchanger with one shell side and one tube side, and has a fourth hot medium passage 510 (for the tube side) and a fourth cold medium passage 520 (for the shell side). The fourth hot medium passage 510 has a fourth hot medium inlet 511 and a fourth hot medium outlet 512. The fourth hot medium inlet 511 is connected to the third cold medium outlet 322 of the third shell side, and the fourth hot medium outlet 512 is connected to the third pipeline 340 via a fourth pipeline 530. The fourth cold medium passage 520 has a fourth cold medium inlet 521 for low-pressure water input and a fourth cold medium outlet 522 for low-pressure water output after heat exchange.

[0094] Example 7:

[0095] like Figure 15 The image shows a preferred embodiment seven of the present invention for a heat recovery system of hot high-temperature gas in a hydrogenation unit. This embodiment is basically the same as embodiment six, except that in this embodiment, there is no need to set up a first bypass line 240. The fourth line 530 is connected to the connecting pipe on the multi-flow wound tube heat exchanger through a second bypass line 540. This connecting pipe is connected to the part of the tube side of the multi-flow wound tube heat exchanger located between the second shell side and the third shell side.

Claims

1. A heat recovery system for hot high pressure gas in a hydrogenation unit, characterized by The utility model relates to a heat exchange device for hydrogenation unit, comprising: a first heat exchanger (100) having a first hot medium channel (110) and a first cold medium channel (120), the first hot medium channel (110) has a first hot medium inlet (111) for the hot high-pressure separator of hydrogenation unit outputting hot high-pressure gas input and a first hot medium outlet (112) for the output of the heat-exchanged hot high-pressure gas, the first cold medium channel (120) has a first cold medium inlet (121) for hydrogen gas or for the mixture of raw oil and hydrogen gas to enter and a first cold medium outlet (122) for the output of the heat-exchanged hydrogen gas or mixture; a second heat exchanger (200) having a second hot medium channel (210) and a second cold medium channel (220), the second hot medium channel (210) has a second hot medium inlet (211) and a second hot medium outlet (212), the second hot medium inlet (211) is communicated with the first hot medium outlet (112) of the first heat exchanger (100); the second cold medium channel (220) has a second cold medium inlet (221) for low-pressure oil or stripping column bottom liquid to enter and a second cold medium outlet (222) for the output of the heat-exchanged low-pressure oil or stripping column bottom liquid; a third heat exchanger (300) having a third hot medium channel (310) and a third cold medium channel (320), the third hot medium channel (310) has a third hot medium inlet (311) and a third hot medium outlet (312), the third hot medium inlet (311) is communicated with the second hot medium outlet (212) of the second heat exchanger (200), the third cold medium channel (320) has a third cold medium inlet (321) for water to enter and a third cold medium outlet (322) for the output of the heat-exchanged water; an air cooler (400) having an inlet communicated with the third hot medium outlet (312) of the third heat exchanger (300) and an outlet connected to the inlet of the cold high-pressure separator of hydrogenation unit; the air cooler (400) comprises: a shell side cylinder (1) vertically arranged, having an air inlet (11) and an air outlet (12) at two ends respectively; two tube sheets arranged on the side wall of the shell side cylinder (1) one above the other; two tube boxes (2) arranged on the corresponding tube sheet respectively; a center cylinder (3) vertically arranged in the shell side cylinder (1); a plurality of heat exchange tubes (4) arranged in the shell side cylinder (1) in the axial direction and spirally wound outside the center cylinder (3) to form a plurality of layers of spiral tubes, the two ends of the heat exchange tubes (4) are supported on the corresponding tube sheet and communicated with the corresponding tube box (2) respectively; A plurality of spray pipes (5) are arranged in the shell side cylinder (1) in the axial direction and are wound in the spiral tubes in each layer along the spiral direction of the heat exchange tubes (4), the lower end of each spray pipe (5) is provided with a liquid inlet (51), the upper end of each spray pipe (5) is provided with a liquid outlet (52) with the opening downward, and the liquid outlet (52) is arranged above the spiral tube and is arranged in the circumferential direction of the shell side cylinder (1) at intervals; meanwhile, a plurality of spray holes (53) are arranged on the wall of each spray pipe (5), and the spray holes (53) are opposite to the wall of the adjacent heat exchange tube (4).

2. The heat recovery system of claim 1, wherein: The third cold medium inlet (321) of the third heat exchanger (300) is connected with a high-pressure water pipeline (330) for conveying high-pressure water, and the third hot medium outlet (312) of the third heat exchanger (300) is connected with the inlet of the air cooler (400) through a third pipeline (340). The fourth heat exchanger (500) is further included, which has a fourth hot medium passage (510) and a fourth cold medium passage (520), the fourth hot medium passage (510) has a fourth hot medium inlet (511) and a fourth hot medium outlet (512), the fourth hot medium inlet (511) is connected with the third cold medium outlet (322) of the third heat exchanger, and the fourth hot medium outlet (512) is connected with the third pipeline (340); the fourth cold medium passage (520) has a fourth cold medium inlet (521) for inputting low-pressure water and a fourth cold medium outlet (522) for outputting low-pressure water after heat exchange.

3. The heat recovery system of claim 2, wherein: The second hot medium outlet (212) of the second heat exchanger (200) and the third hot medium inlet (311) of the third heat exchanger (300) are connected through a second pipeline (230), and the second pipeline (230) and the high-pressure water pipeline (330) are connected through a first bypass pipeline (240).

4. The heat recovery system of claim 2, wherein: The second hot medium outlet (212) of the second heat exchanger (200) and the third hot medium inlet (311) of the third heat exchanger (300) are connected through a second pipeline (230), the fourth hot medium outlet (512) of the fourth heat exchanger (500) and the third pipeline (340) are connected through a fourth pipeline (530), and the fourth pipeline (530) and the second pipeline (230) are connected through a second bypass pipeline (540).

5. The heat recovery system of claim 2, wherein: The first, second, third and fourth heat exchangers are single-flow winding tube heat exchangers with one shell side and one tube side, the tube side of the first, second and third heat exchangers is a hot medium passage, and the shell side is a cold medium passage; the tube side of the fourth heat exchanger (500) is the fourth cold medium passage (520), and the shell side is the fourth hot medium passage (510).

6. The heat recovery system of claim 2, wherein: The first, second and third heat exchangers are combined into a multi-stream winding pipe heat exchanger with one tube pass and three shell passes, and the first heat medium passage (110) of the first heat exchanger (100), the second heat medium passage (210) of the second heat exchanger (200) and the third heat medium passage (310) of the third heat exchanger (300) are sequentially connected and serve as the tube pass of the multi-stream winding pipe heat exchanger, and the first heat medium inlet (111) of the first heat medium passage (110) serves as the tube pass inlet, and the third heat medium outlet (312) of the third heat medium passage (310) serves as the tube pass outlet. The first, second and third heat exchangers are combined into a multi-stream winding pipe heat exchanger with one tube pass and three shell passes, and the first heat medium passage (110) of the first heat exchanger (100), the second heat medium passage (210) of the second heat exchanger (200) and the third heat medium passage (310) of the third heat exchanger (300) are sequentially connected and serve as the tube pass of the multi-stream winding pipe heat exchanger, and the first heat medium inlet (111) of the first heat medium passage (110) serves as the tube pass inlet, and the third heat medium outlet (312) of the third heat medium passage (310) serves as the tube pass outlet.

7. The heat recovery system of claim 6, wherein: The fourth heat exchanger (500) is a single-stream winding pipe heat exchanger with a single tube pass and a single shell pass, and the single tube pass is the heat medium passage and the single shell pass is the cold medium passage.

8. The heat recovery system of claim 1, wherein: The first heat medium outlet (112) of the first heat exchanger (100) and the second heat medium inlet (211) of the second heat exchanger (200) are connected by the first pipeline (130), and the first pipeline (130) is connected with the first water injection pipeline (140). The first heat medium inlet (111) of the first heat exchanger (100) is connected with the hot high-temperature gas pipeline (150) for conveying hot high-temperature gas, and the hot high-temperature gas pipeline (150) is connected with the second water injection pipeline (160).

9. The heat recovery system according to any one of claims 1 to 8, characterized in that: The pipe opening at the upper end of each spray pipe (5) is connected with a spray head (54) capable of spraying water downward.

10. The heat recovery system according to any one of claims 1 to 8, wherein: The bottom of the shell pass cylinder (1) is provided with a water collecting tank (6), and the liquid inlet (51) of the spray pipe (5) is connected with the water collecting tank (6) through a water pump (7).

11. The heat recovery system of claim 10, wherein: The air inlet (11) is located at the lower end of the shell pass cylinder (1), and the air outlet (12) is located at the upper end of the shell pass cylinder (1).

12. The heat recovery system of claim 11, wherein: A water collector (8) is further included, which is arranged in the shell pass cylinder (1) and located above the liquid outlet (52) of the spray pipe (5), and the water collector (8) has a passage (80) through which air flows upward and collects water in the air flow.

13. The heat recovery system of claim 12, wherein: The water collector (8) includes a plurality of vertically arranged and connected water collection plates (81). The plurality of water collection plates (81) are arranged at intervals in the horizontal direction. The aforementioned channel (80) is formed between the surfaces of two adjacent water collection plates (81). At the same time, an upwardly extending lip (811) is provided on the surface of each water collection plate (81). A water collection ditch (82) with an upward opening is formed between the lip (811) and the surface of the water collection plate (81) for collecting water accumulated on the surface above the lip.

14. The heat recovery system of claim 13, wherein: The water collector (8) also includes a water collection trough (83) located in the center of the water collector (8) and extending through the water collection plate (81) along the arrangement direction of the water collection plate (81). The water collection ditch (82) extends from the outside to the inside of the water collection plate (81) to the water collection trough (83) and is connected to the water collection trough (83). The water collector (8) is fitted around the outer periphery of the central cylinder (3), and the water collection trough (83) allows the central cylinder (3) to pass through. The interior of the central cylinder (3) is hollow, and its lower port (31) is connected to the water collection tank (6). The central cylinder (3) has an inlet (32) on the cylinder wall opposite to the water collection trough (83) that is connected to the water collection trough (83).

15. The heat recovery system of claim 13, wherein: The interval between two adjacent water collection plates (81) is 20~50mm.

16. The heat recovery system of claim 12, wherein: The water collector (8) includes multiple vertically arranged and interconnected water collection plates (81). The multiple water collection plates (81) are arranged circumferentially around the periphery of the central cylinder (3). The aforementioned channel (80) is formed between the surfaces of two adjacent water collection plates (81). Each water collection plate (81) has an upwardly extending lip (811) protruding from its surface. The lip (811) and the surface of the water collection plate (81) form an upward-facing water collection ditch (82) for collecting moisture in the airflow. Each water collection ditch (82) extends from the outside to the inside of the surface of the water collection plate (81) toward the central cylinder (3). The interior of the central cylinder (3) is hollow, and its lower end (31) is connected to the aforementioned water collection tank (6). The central cylinder (3) has a water inlet (32) on its wall opposite to the water collector (8), and the water inlet (32) is connected to the aforementioned water collection ditch (82).

17. The heat recovery system of claim 14, wherein: The water collection ditch (82) slopes downward from the outside to the inside.

18. The heat recovery system of claim 14, wherein: Each water collection plate (81) is made into a wave-shaped structure from top to bottom. Each water collection plate (81) has at least one of the above-mentioned water collection grooves (82) on the same side surface, and each water collection groove (82) is located at the protruding part of the surface of each water collection plate (81).

19. The heat recovery system of any one of claims 1-8, wherein: The heat exchange tube (4) is a corrugated tube, and has a smooth tube section (41) and a corrugated section (42) with a corrugated surface. The corrugated section (42) and the smooth tube section (41) are arranged alternately along the length of the heat exchange tube (4), and the length of the corrugated section (42) is greater than the length of the smooth tube section (41). Alternatively, the heat exchange tube (4) is a finned tube, having a smooth tube section and a finned section with fins on its surface. The finned section and the smooth tube section are arranged alternately along the length of the heat exchange tube (4), and the length of the finned section is greater than the length of the smooth tube section.

20. The heat recovery system of any one of claims 1-8, wherein: The two tube plates and the two tube boxes (2) described above form a group, and there are at least two groups and are arranged along the circumference of the shell side cylinder (1).

Images