An energy-saving atmospheric and vacuum five-tower distillation apparatus and distillation method

Abstract

This application provides an energy-saving atmospheric and vacuum five-tower distillation apparatus and method. The apparatus includes a primary distillation tower, a negative pressure tower, an atmospheric pressure tower, and a vacuum tower. The negative pressure towers include a first negative pressure tower and a second negative pressure tower. The tops of the first and second negative pressure towers are respectively connected to reflux devices for the first and second negative pressure towers. A reboiler is installed in the lower middle part of the first negative pressure tower. The pressure of the first negative pressure tower is higher than that of the second negative pressure tower. The addition of two negative pressure towers between the primary distillation tower and the atmospheric pressure tower allows for timely separation of vaporized gasoline and kerosene components, reducing the irreversibility of heating and cooling, and achieving energy saving. The negative pressure operation of the first and second negative pressure towers lowers the operating temperature within the two towers, which is beneficial for the utilization of low-grade heat in the system. This ensures that all gasoline components and some kerosene components of the crude oil are extracted before entering the atmospheric pressure tower, reducing energy consumption, improving heat utilization, and increasing the precision of crude oil separation.

Description

Technical Field

[0001] This application relates to the field of chemical equipment technology, specifically to an atmospheric and vacuum distillation apparatus with energy-saving effects. Background Technology

[0002] Atmospheric and vacuum distillation units are among the most energy-intensive units in oil refining, accounting for 25%-30% of the total energy consumption of a refinery. Therefore, reducing the energy consumption of atmospheric and vacuum distillation units is of paramount importance to the energy conservation, consumption reduction, and economic indicators of oil refineries. Traditional atmospheric and vacuum distillation units consist of a primary distillation column, an atmospheric column, and a vacuum distillation column. After electro-desalting, crude oil is heated by heat exchange and enters the primary distillation column, where the lightest fraction of the crude oil is fractionated. The liquid phase drawn from the bottom of the primary distillation column is further heated to a specified temperature in a furnace through heat exchange and then enters the atmospheric column, where gasoline, kerosene, and diesel products are produced. The liquid phase drawn from the bottom of the atmospheric column is heated to a certain temperature through a heat exchange network and a furnace before entering the vacuum distillation column to extract heavier products.

[0003] Currently, energy saving in atmospheric and vacuum distillation units mainly focuses on optimizing equipment such as heating furnaces and high-efficiency internal components, and optimizing the heat exchange network using "pinch technology." There is relatively little optimization of the overall process. However, there is room for energy saving optimization in the current atmospheric and vacuum distillation process. Before entering the primary distillation tower, crude oil is preheated in the heat exchange network, and some gasoline and kerosene components have already vaporized. However, due to the limited separation efficiency of the fractionation tower, the gasoline components cannot be completely extracted. This portion of gas is repeatedly cooled and evaporated, increasing energy consumption. For example, a petroleum atmospheric and vacuum distillation process with application number 201110102559.1 provides a technical solution where the feed inlet of the vacuum distillation tower or / and the atmospheric tower is connected to the tube side of a partitioned heat exchanger, the shell-side inlet of the partitioned heat exchanger is connected to a molten salt heater, and the shell-side outlet is connected to a molten tank. The molten salt heater is also connected to the molten tank. Mixed inorganic salt powder particles are added to the molten tank. High-pressure steam or electricity is introduced into the melting tank to melt the mixed inorganic salt powder particles into a liquid. When the melting temperature reaches 180°C, the molten salt circulation pump is turned on to force the molten salt to circulate in the liquid phase and transport it to the molten salt heating furnace for heating. The molten salt temperature at the outlet of the molten salt furnace or the inlet temperature of the molten salt flow in the indirect heat exchanger is controlled between 350°C and 530°C. The molten salt is then transported to the indirect heat exchanger to heat the oil flow to 360°C to 440°C before returning to the melting tank. The oil flows out of the indirect heat exchanger and enters the atmospheric or vacuum distillation tower. This method has a low probability of coking and can improve the heating temperature and the extraction rate of the distillation tower. In the above scheme, the heating furnace before the distillation tower in the existing technology is replaced with an indirect heat exchanger where molten salt and oil exchange heat. The heat of heating of the oil is provided by the indirect heat exchanger. This requires the addition of a new indirect heat exchanger for molten salt and oil to the entire system. Energy saving is achieved through equipment optimization.

[0004] In the above scheme, the utilization rate of the existing heating furnace is 0, and the gasoline component of the crude oil cannot be completely extracted before entering the atmospheric distillation tower. The applicant conducted a detailed search of the prior art and found no prior art documents related to "atmospheric and vacuum distillation five-tower distillation".

[0005] In summary, a new technical solution is needed to address the aforementioned technical problems. Summary of the Invention

[0006] This application provides an energy-saving five-tower distillation apparatus with atmospheric and vacuum distillation capabilities, comprising a primary distillation tower, an atmospheric distillation tower, and a vacuum distillation tower. The primary distillation tower has a reboiler at its bottom and a reflux device connected to its top. The atmospheric distillation tower also has a reflux device connected to its top. A feed device is located at the front of the primary distillation tower. A vacuum distillation tower is located between the primary distillation tower and the atmospheric distillation tower. The vacuum distillation tower includes a first vacuum distillation tower connected to the primary distillation tower, a first vacuum distillation tower reflux device connected to its top, and a reboiler located in the lower middle section of the first vacuum distillation tower. The first vacuum distillation tower is connected to a second vacuum distillation tower via a pipeline, which is equipped with a reboiler heating system. The top of the second vacuum distillation tower is connected to a second vacuum distillation tower reflux device. The pressure of the first vacuum distillation tower is higher than that of the second vacuum distillation tower. The bottom of the second vacuum distillation tower is connected to the lower middle section of the atmospheric distillation tower. A second vacuum distillation tower reboiler heating system is located between the second vacuum distillation tower and the atmospheric distillation tower.

[0007] As a preferred embodiment, at least one of the primary distillation tower reflux device, the first negative pressure tower reflux device, and the second negative pressure tower reflux device is connected to the naphtha separation device; the naphtha separation device includes a naphtha separation tower feed buffer tank, which is connected to the naphtha separation tower; a naphtha separation tower reflux device is provided at the top of the naphtha separation tower, which is connected to the light naphtha production pipeline; and a heavy naphtha production pipeline is provided at the bottom of the naphtha separation tower.

[0008] As a preferred embodiment, the feeding device includes a crude oil feed pipeline 1, which is connected to a desalting tank. A crude oil feed pump 1 and a crude oil heating system are installed on the crude oil feed pipeline 1. The desalting tank is connected to a flash tank via a crude oil feed pipeline 2, which is equipped with a crude oil feed pump 2 and a heater 2. The flash tank is connected to the primary distillation tower via a crude oil feed pipeline 3, which is equipped with a crude oil feed pump 3. The top of the flash tank is connected to a secondary flash tank, and the bottom of the secondary flash tank is connected to the naphtha separator feed buffer tank via a secondary flash tank pipeline. A non-condensable gas pipeline is connected to the top of the secondary flash tank.

[0009] As a preferred embodiment, the atmospheric pressure tower is connected to the atmospheric pressure stripping tower via an atmospheric pressure tower side line. One side of the atmospheric pressure stripping tower is connected to atmospheric pressure stripping tower production pipeline 1, atmospheric pressure stripping tower production pipeline 2, and atmospheric pressure stripping tower production pipeline 3. One side of the vacuum tower is connected to the vacuum stripping tower via a vacuum stripping tower side line. One side of the vacuum stripping tower is connected to vacuum stripping tower side lines 2, 3, 4, and 5. The upper part of vacuum stripping tower 2 is connected to vacuum stripping tower side line 1 on the vacuum tower, and the lower part of vacuum stripping tower side line 5 is connected to vacuum stripping tower side line 6 on the vacuum tower. The bottom of the vacuum tower is connected to a vacuum residue oil production pipeline.

[0010] As a preferred embodiment, the crude oil heating system is connected to the top of the primary distillation tower, the top of the atmospheric distillation tower, the top of the first negative pressure tower, and the top of the second negative pressure tower, respectively. The gas phase at the top of the primary distillation tower, the top of the atmospheric distillation tower, the top of the first negative pressure tower, and the top of the second negative pressure tower exchange heat with the crude oil in the crude oil heating system, thereby providing heat to the crude oil heating system.

[0011] As a preferred option, the middle section of the negative pressure tower is equipped with a circulating heat extraction system.

[0012] As a preferred embodiment, the secondary section of the negative pressure tower is used to exchange heat between the liquid phase extracted from the secondary section of the negative pressure tower and the crude oil in the crude oil heating system, thereby providing heat to the crude oil heating system.

[0013] As a preferred embodiment, the atmospheric pressure tower is provided with a first-stage circulating heat extraction section and a second-stage circulating heat extraction section on one side; the pressure reducing tower is also provided with a first-stage circulating heat extraction section, a second-stage circulating heat extraction section, and a third-stage circulating heat extraction section on one side.

[0014] As a preferred option, the liquid phase extracted from the middle section of the depressurization tower is exchanged with the crude oil in the crude oil heating system to provide heat for the crude oil heating system.

[0015] As a preferred embodiment, the middle section of the primary distillation column is equipped with a primary distillation column circulating heating device.

[0016] As a preferred embodiment, the atmospheric stripping tower outlet pipeline 1 is sequentially connected to the bottom heating system of the negative pressure tower 1 and the intermediate circulation heating device of the primary distillation tower; the atmospheric stripping tower outlet pipeline 2 is sequentially connected to the bottom heating system of the negative pressure tower 1 and the naphtha fractionation tower feed heater; the atmospheric stripping tower outlet pipeline 3 is sequentially connected to the bottom heating system of the negative pressure tower 1, the reboiler of the primary distillation tower, and the intermediate circulation heating device of the primary distillation tower; the reduced pressure tower outlet pipeline 3 is sequentially connected to the bottom heating system of the negative pressure tower 1 and the intermediate circulation heating device of the primary distillation tower; the reduced pressure tower outlet pipeline 4 is sequentially connected to the bottom heating system of the negative pressure tower 1... The reboiler unit of the primary distillation tower and the circulating heating unit of the middle section of the primary distillation tower are connected in sequence; the side line of the reduced pressure tower 5 is connected in sequence to the bottom heating system of the second negative pressure tower, the bottom heating system of the first negative pressure tower, and the circulating heating unit of the middle section of the primary distillation tower; the side line of the reduced pressure tower 6 is connected in sequence to the bottom heating system of the second negative pressure tower, the reboiler unit of the primary distillation tower, the bottom heating system of the first negative pressure tower, and the circulating heating unit of the middle section of the primary distillation tower; the vacuum residue production pipeline is connected in sequence to the bottom heating system of the second negative pressure tower, the reboiler unit of the primary distillation tower, the bottom heating system of the first negative pressure tower, the circulating heating unit of the middle section of the primary distillation tower, and the crude oil heating system.

[0017] As a preferred embodiment, the first stage of the atmospheric distillation column uses circulating heat extraction to exchange heat sequentially with the reboiler of the primary distillation column, the bottom heating system of the first negative pressure column, and the reboiler of the separation column; the second stage of the atmospheric distillation column uses circulating heat extraction to exchange heat sequentially with the bottom heating system of the second negative pressure column and the circulating heating device of the primary distillation column; the second stage of the vacuum distillation column uses circulating heat extraction to exchange heat sequentially with the bottom heating system of the first negative pressure column, the bottom heating system of the second negative pressure column, the reboiler of the primary distillation column, and the circulating heating device of the primary distillation column; and the third stage of the vacuum distillation column uses circulating heat extraction to exchange heat sequentially with the bottom heating system of the second negative pressure column.

[0018] A distillation method for an energy-saving atmospheric and vacuum five-tower distillation apparatus includes the following steps:

[0019] S1: Crude oil enters the desalting tank through the crude oil heating system for desalting and dehydration, and then is heated by heater two. The heated material enters the primary distillation tower. S2: The overhead reflux device at the top of the primary distillation tower extracts the overhead gas and light gasoline from the primary distillation tower. S3: The bottom oil from the primary distillation tower enters negative pressure tower one. The vapor phase at the top of negative pressure tower one is condensed, and part of it is refluxed back to negative pressure tower one, while the rest undergoes naphtha separation. S4: The material at the bottom of negative pressure tower one is heated and enters negative pressure tower two. The vapor phase at the top of negative pressure tower two is condensed, and part of it is refluxed back to negative pressure tower two, while the rest undergoes naphtha separation. S5: The bottom oil from the bottom of negative pressure tower two is heated and enters the atmospheric distillation tower. The vapor phase at the top of the tower is condensed and then refluxed back to the atmospheric tower. The atmospheric tower is connected to the atmospheric stripping tower. Different finished oil products with different compositions are collected from the atmospheric stripping tower's outflow pipelines 1, 2, and 3. S6: The bottom oil of the atmospheric tower is heated and then enters the vacuum tower. The steam jet device at the top of the vacuum tower extracts the top gas and maintains the vacuum at the top of the tower. Condensed oil and water are collected from the top of the vacuum tower. S7: The bottom of the vacuum tower is collected as residue oil. The vacuum tower is connected to the vacuum stripping tower. The vacuum stripping tower's side line 1 and side line 6, and the vacuum stripping tower's side lines 2, 3, 4, and 5 collect the corresponding oil products from each vacuum stripping tower line.

[0020] As a preferred option, the gas phase from the top of the primary distillation column, the gas phase from the top of the atmospheric distillation column, the gas phase from the top of the first negative pressure column, the gas phase from the top of the second negative pressure column, and the liquid phase extracted from the circulating heat extraction section of the second negative pressure column are used to exchange heat with the crude oil in the crude oil heating system to provide heat for the crude oil heating system.

[0021] This application has the following advantages:

[0022] 1. All gasoline components and some kerosene components of crude oil are extracted before entering the atmospheric distillation tower, reducing energy consumption, improving heat utilization, and enhancing crude oil separation accuracy. 2. Two negative pressure towers are added between the primary distillation tower and the atmospheric distillation tower, which can promptly separate the vaporized gasoline and kerosene components, reducing the irreversibility of heating and cooling and achieving energy saving. Furthermore, the negative pressure operation of the two negative pressure towers lowers the operating temperature within the towers, facilitating the utilization of low-grade heat in the system. 3. The extraction of all gasoline components and some kerosene components by the two negative pressure towers reduces the amount of material entering the atmospheric heating furnace, lowering the furnace load and directly reducing fuel oil consumption, further achieving energy saving. 4. The heat from the top, middle sections, and extraction pipelines of each tower is fully utilized. Only the atmospheric and vacuum heating furnaces require external heat sources; the remaining heat sources utilize the unit's own heat, eliminating the need for heat pumps and improving heat utilization, further achieving energy saving. Attached Figure Description

[0023] Figure 1This is a schematic diagram of the structure of this application;

[0024] Figure 2 This is a schematic diagram of the heat cycle in this application;

[0025] 1. Crude distillation column; 2. Atmospheric distillation column; 3. Vacuum distillation column; 4. Crude distillation column mid-section circulating heating device; 5. Crude distillation column reboiler; 6. Crude distillation column reflux tank; 8. Crude distillation column top condenser; 9. Crude distillation column reflux line; 10. Product line; 11. Atmospheric distillation column reflux tank; 12. Atmospheric distillation column top product line; 13. Atmospheric distillation column condenser; 14. Atmospheric distillation column reflux line; 15. Atmospheric distillation column reflux pump; 16. Vacuum distillation column one; 17. Vacuum distillation column one reflux tank; 19. Vacuum distillation column one condenser; 20. Vacuum distillation column one reflux line; 21. Product line two; 22. Vacuum distillation column reboiler; 23. Line; 24. Vacuum distillation column two; 25. Vacuum distillation column one reboiler heating system; 26. Vacuum distillation column two reflux tank; 28. Vacuum distillation column two condenser; 29. 30. Negative Pressure Tower II Reflux Pipeline; 31. Production Pipeline III; 32. Negative Pressure Tower Stripping Tower; 33. Kerosene Production Pipeline; 34. Kerosene Production Pump; 35. Negative Pressure Tower II Boiler Pipeline; 36. Negative Pressure Tower Boiler Pump; 37. Atmospheric Pressure Heater; 38. Atmospheric Pressure Tower Boiler Pipeline; 39. Vacuum Pressure Heater; 40. Naphtha Separator Feed Buffer Tank; 41. Feed Pipeline; 42. Naphtha Separator; 43. Feed Pump; 44. Naphtha Fractionation Tower Raw Material Heater; 45. Light Naphtha Production Pipeline; 46. Heavy Naphtha Production Pipeline; 47. Separator Top Production Pipeline; 48. Separator Condenser; 49. Separator Reflux Pipeline; 50. Crude Oil Feed Pipeline I; 51. Separator Reboiler; 52. Desalting Tank 53. Crude oil feed line 2; 54. Flash tank; 55. Crude oil feed line 3; 56. Crude oil feed pump 1; 57. Crude oil heating system; 58. Crude oil feed pump 2; 59. Heater 2; 60. Crude oil feed pump 3; 61. Secondary flash tank; 62. Secondary flash tank pipeline; 64. Non-condensable gas pipeline; 65. Feed pump 4; 66. Atmospheric stripping tower; 67. Atmospheric tower side line 1; 68. Atmospheric tower side line 2; 69. Atmospheric tower side line 3; 70. Atmospheric tower reflux side line 1; 71. Atmospheric tower reflux side line 2; 72. Atmospheric tower reflux side line 3; 73. Atmospheric stripping tower production line 1; 74. Atmospheric stripping tower production line 2; 75. Atmospheric stripping tower production line 3; 76. Production pump; 77. First section of intermediate section of atmospheric tower. 78. Circulating heat extraction; 79. Condensate buffer tank; 80. Top pipeline of vacuum tower; 81. Steam injection device; 82. Condensate production pipeline; 83. Vacuum stripping tower; 84. Side pipeline of vacuum tower; 85. Reflux side pipeline of vacuum tower; 86. Side pipeline of vacuum tower II; 87. Side pipeline of vacuum tower III; 88. Side pipeline of vacuum tower IV; 89. Side pipeline of vacuum tower V; 90. Side pipeline of vacuum tower I; 91. Side pipeline of vacuum tower VI; 92. Vacuum residue production pipeline; 93. Circulating heat extraction in the first section of the middle section of vacuum tower; 94. Circulating heat extraction in the middle section of vacuum tower II; 95. Boiler heating system of vacuum tower II; 96. Circulating heat extraction in the second section of the middle section of atmospheric tower; 97. Circulating heat extraction in the second section of the middle section of vacuum tower; 98. Circulating heat extraction in the third section of the middle section of vacuum tower; 99. Crude oil pipeline I; 100. Crude oil pipeline II;101. Crude Oil Pipeline 3; 102. Crude Oil Pipeline 4; 103. Crude Oil Heater 1; 104. Crude Oil Heater 2; 105. Crude Oil Heater 3; 106. Crude Oil Heater 4; 107. Crude Oil Heater 5; 108. Crude Oil Heater 6; 109. Crude Oil Heater 7; 110. Crude Oil Heater 8; 111. Crude Oil Heater 9; 112. Crude Oil Heater 10; 113. Crude Oil Heater 11; 114. Crude Oil Heater 12; 115. Heating Pipeline 1 of Negative Pressure Tower 1; 116. Heating Pipeline 2 of Negative Pressure Tower 1; 117. Heating Pipeline 3 of Negative Pressure Tower 1; 118. Heating Pipeline 4 of Negative Pressure Tower 1; 119. Heater 1 of Negative Pressure Tower 1; 120. Heater 2 of Negative Pressure Tower 1; 121. Negative Pressure... 122. Heater 3 of Tower 1; 123. Heater 4 of Tower 1; 124. Heater 5 of Tower 1; 125. Heater 6 of Tower 1; 126. Heater 7 of Tower 1; 127. Heater 8 of Tower 1; 128. Heater 9 of Tower 1; 129. Heater 11 of Tower 1; 130. Heater 12 of Tower 1; 131. Heater 13 of Tower 1; 132. Heater 14 of Tower 1; 133. Heater 15 of Tower 1; 134. Main Pipeline for Middle Drainage of Primary Distillation Tower; 135. Branch Pipeline 1 for Middle Drainage of Primary Distillation Tower; 136. Branch Pipeline 2 for Middle Drainage of Primary Distillation Tower; 137. Branch Pipeline 3 for Middle Drainage of Primary Distillation Tower; 138. Branch Pipeline 1 for Middle Drainage of Primary Distillation Tower Pipeline 4; 139. Middle section of the primary distillation column, branch pipeline 5; 140. Middle section of the primary distillation column, branch pipeline 6; 141. Middle section of the primary distillation column, branch pipeline 7; 142. Middle section of the primary distillation column, branch pipeline 8; 143. Middle section of the primary distillation column, branch pipeline 9; 144. Middle section of the primary distillation column, reflux main pipeline; 145. Middle section of the primary distillation column, heater 1; 146. Middle section of the primary distillation column, heater 2; 147. Middle section of the primary distillation column, heater 3; 148. Middle section of the primary distillation column, heater 4; 149. Middle section of the primary distillation column, heater 5; 150. Middle section of the primary distillation column, heater 6; 151. Middle section of the primary distillation column, heater 7; 152. Middle section of the primary distillation column, heater 8; 153. Middle section of the primary distillation column, heater 9; 154. Middle section of the primary distillation column, reboiler feed main pipeline; 1 55. Feed branch pipe 1 for the reboiler of the primary distillation column; 156. Feed branch pipe 2 for the reboiler of the primary distillation column; 157. Feed branch pipe 3 for the reboiler of the primary distillation column; 158. Feed branch pipe 4 for the reboiler of the primary distillation column; 159. Feed branch pipe 5 for the reboiler of the primary distillation column; 160. Feed branch pipe 6 for the reboiler of the primary distillation column; 161. Main discharge pipe for the reboiler of the primary distillation column; 162. Reboiler 1 for the primary distillation column; 163. Reboiler 2 for the primary distillation column; 164. Reboiler 3 for the primary distillation column; 165. Reboiler 4 for the primary distillation column; 166. Reboiler 5 for the primary distillation column; 167. Reboiler 6 for the primary distillation column; 168. Heating line 1 for the second negative pressure column; 169. Heating line 2 for the second negative pressure column; 170. Heater 1 for the second negative pressure column; 171. Heater 2 for the second negative pressure column; 172. Negative pressure tower two heater three; 173. Negative pressure tower two heater four;174. Heater 5 of Negative Pressure Tower II; 175. Heater 6 of Negative Pressure Tower II; 176. Heater 7 of Negative Pressure Tower II; 177. Heater 8 of Negative Pressure Tower II; 178. Heater 9 of Negative Pressure Tower II; 179. Heater 10 of Negative Pressure Tower II. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1 Appendix Figure 2 The specific embodiments of the present invention will be described in detail below. It should be noted that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0027] Example 1:

[0028] This embodiment provides an energy-saving atmospheric and vacuum distillation five-tower system, including a primary distillation tower 1, an atmospheric distillation tower 2, and a vacuum distillation tower 3. Preferably, the operating pressure of the primary distillation tower 1 is reduced to between slightly positive and slightly negative pressure. A primary distillation tower mid-section circulating heating device 4 is installed in the middle section of the primary distillation tower 1 to circulate and heat the material in the middle section of the primary distillation tower 1. By reducing the operating pressure of the primary distillation tower 1 and increasing the circulating heating in the middle section of the primary distillation tower 1, the required heat grade of the primary distillation tower 1 is reduced, thereby increasing the energy utilization efficiency. A primary distillation tower reboiler 5 is installed at the bottom of the primary distillation tower 1, which is heated through a heat exchange network. A primary distillation tower reflux device is connected to the top of the primary distillation tower 1. Specifically, the primary distillation tower reflux device includes a primary distillation tower reflux tank 6, which is connected to the primary distillation tower 3. The top of distillation column 1 is connected via a primary distillation column top outlet pipeline, which is equipped with a primary distillation column top condenser 8. The bottom of the primary distillation column reflux tank 6 is connected to a primary distillation column reflux tank outlet pipeline, which is equipped with an outlet pump. The primary distillation column reflux tank outlet pipeline is connected to a primary distillation column reflux pipeline 9 and an outlet pipeline 10, respectively. The primary distillation column reflux pipeline 9 is connected to the upper middle part of the primary distillation column 1. The gas phase at the top of the primary distillation column 1 is condensed by the primary distillation column top condenser 8 and enters the primary distillation column reflux tank 6. The gas phase in the primary distillation column reflux tank 6 is outleted via a non-condensable gas pipeline. Part of the liquid phase in the primary distillation column reflux tank 6 is returned to the primary distillation column 1 via the primary distillation column reflux pipeline 9, and part of it is outleted as light gasoline via the outlet pipeline 10. The top of atmospheric distillation column 2 is connected to an atmospheric distillation column reflux device, which includes an atmospheric distillation column reflux tank 11. The atmospheric distillation column reflux tank 11 is connected to the top of atmospheric distillation column 2 via a top outlet pipeline 12. An atmospheric distillation column condenser 13 is connected to the top outlet pipeline 12. An atmospheric distillation column reflux pipeline 14 is connected to the bottom of the atmospheric distillation column 11, and an atmospheric distillation column reflux pump 15 is installed on the atmospheric distillation column 14. The atmospheric distillation column reflux pipeline 14 is connected to the upper part of atmospheric distillation column 2. The gas phase at the top of atmospheric distillation column 2 is condensed by the atmospheric distillation column condenser 13 and then enters the atmospheric distillation column reflux tank 11. The liquid phase in the atmospheric distillation column reflux tank 11 is refluxed back to atmospheric distillation column 2 via the atmospheric distillation column reflux pipeline 14. A feed device is installed at the front of the primary distillation column 1, through which crude oil passes... The feed enters the primary distillation column 1 for processing. A negative pressure column is set between the primary distillation column 1 and the atmospheric column 2. The negative pressure column includes a negative pressure column 16 connected to the primary distillation column 1. A negative pressure column reflux device is connected to the top of the negative pressure column 16. The negative pressure column reflux device includes a negative pressure column reflux tank 17. The negative pressure column reflux tank 17 is connected to the top of the negative pressure column 16 through a negative pressure column top outlet pipeline. A negative pressure column condenser 19 is set on the negative pressure column top outlet pipeline. A negative pressure column reflux tank outlet pipeline is connected to the bottom of the negative pressure column reflux tank 17. The negative pressure column reflux tank outlet pipeline is connected to a negative pressure column reflux pipeline 20 and an outlet pipeline 21, respectively. The negative pressure column reflux pipeline 20 is connected to the middle and upper part of the negative pressure column 16.The vapor phase at the top of negative pressure tower 16 is condensed by negative pressure tower condenser 19 and then enters negative pressure tower reflux tank 17. Part of it flows back to negative pressure tower 16 through negative pressure tower reflux pipeline 20, and part of it is extracted through extraction pipeline 21. A negative pressure tower reboiler 22 is installed in the middle and lower part of negative pressure tower 16, which provides heat for crude oil fractionation. Negative pressure tower 16 is connected to negative pressure tower 24 through pipeline 23. A negative pressure tower reboiler heating system 25 is installed on pipeline 23. The negative pressure tower reboiler heating system 25 obtains the heat required for evaporation in the form of high-temperature feed. A negative pressure tower 24 reflux device is connected to the top of negative pressure tower 24. The negative pressure tower 2 reflux device includes components connected to negative pressure tower 24. 4. The upper part is connected to the second reflux pipeline 29 of the negative pressure tower. The second reflux pipeline 29 is equipped with the second condenser 28 and the second reflux tank 26 of the negative pressure tower in sequence. The lower part of the second reflux pipeline 29 of the negative pressure tower is connected to the third extraction pipeline 30. The middle part of the second negative pressure tower 24 is equipped with the second negative pressure tower middle section circulating heat extraction 94. The second negative pressure tower middle section circulating heat extraction is used to utilize the heat of the liquid phase extracted from the middle section of the second negative pressure tower to reduce the amount of condensation at the top of the second negative pressure tower 24. Preferably, in order to improve the fractionation accuracy, the lower middle part of the second negative pressure tower 24 is connected to the stripping tower 31 of the negative pressure tower. The bottom of the stripping tower 31 is connected to the kerosene extraction pipeline 32. The kerosene extraction pipeline 32 is equipped with kerosene extraction... Pump 33; The pressure of negative pressure tower 16 is higher than that of negative pressure tower 24. The bottom of negative pressure tower 24 is connected to the lower middle part of atmospheric pressure tower 2 through negative pressure tower 2 bottom pipeline 34. Negative pressure tower bottom pump 35, negative pressure tower bottom heating system 95, and atmospheric pressure heater 36 are installed on negative pressure tower bottom pipeline 34. Atmospheric pressure heater 36 is used to heat the material in the bottom of negative pressure tower 24. The bottom of atmospheric pressure tower 2 is connected to the upper middle part of vacuum tower 3 through atmospheric pressure tower bottom pipeline 37. Vacuum pressure heater 38 is installed on atmospheric pressure tower bottom pipeline 37. Vacuum pressure heater 38 is used to heat the material in the bottom of atmospheric pressure tower 2. In this embodiment, by adding two negative pressure towers between primary distillation tower 1 and atmospheric pressure tower 2... The reboiler 22 in the lower part of the negative pressure tower 16 provides heat for crude oil fractionation. The tower bottom heating system 25 of the negative pressure tower 1 obtains the heat required for evaporation through high-temperature feed, which can promptly separate the vaporized gasoline and kerosene components, reducing the irreversibility of heating and cooling and achieving energy saving. Negative pressure towers 16 and 24 extract all gasoline components and part of the kerosene components, reducing the amount of material entering the atmospheric pressure heater 36, lowering the load on the atmospheric pressure heater 36, directly reducing the fuel oil consumption of the unit, and further achieving energy saving. In addition, the negative pressure operation of negative pressure towers 16 and 24 lowers the operating temperature inside the tower, which is beneficial to the utilization of low-grade heat in the system.

[0029] Example 2:

[0030] This embodiment enables further processing of the materials collected from the tops of primary distillation column 1, negative pressure column 16, and negative pressure column 24 to extract naphtha. Specifically:

[0031] At least one of the primary distillation column reflux device, the first negative pressure column reflux device, and the second negative pressure column reflux device is connected to the naphtha separation device. In this embodiment, it is taken that the primary distillation column reflux device, the first negative pressure column reflux device, and the second negative pressure column reflux device are respectively connected to the naphtha separation device. The naphtha separation device includes a naphtha separation tower feed buffer tank 39. The production pipeline 10, the second production pipeline 21, and the third production pipeline 30 are respectively connected to the naphtha separation tower feed buffer tank 39. The naphtha separation tower feed buffer tank 39 is connected to the naphtha separation tower 41 through a feed pipe 40. A feed pump 42 and a naphtha fractionation tower feed heater 43 are installed on the feed pipe 40. A reboiler 51 is provided at the bottom of the naphtha separation tower 41, and a reboiler 51 is provided at the top of the naphtha separation tower 41. The naphtha separation tower reflux device is connected to the light naphtha production line 44, and the bottom of the naphtha separation tower 41 is equipped with a heavy naphtha production line 45. The naphtha separation tower reflux device includes a separation tower reflux tank 46, which is connected to the top of the naphtha separation tower 41 via a separation tower top production line 47. A separation tower condenser 48 is installed on the separation tower top production line 47, and a separation tower reflux line 49 is installed at the bottom of the separation tower reflux tank 46. The separation tower reflux line 49 is connected to the middle and upper part of the naphtha separation tower 41. The naphtha separation device can further separate the materials produced from the top of the primary distillation tower 1, the negative pressure tower 16, and the negative pressure tower 24 to produce light naphtha and heavy naphtha.

[0032] Example 3:

[0033] This embodiment can further reduce gas loss in the primary distillation column 1, specifically:

[0034] The feeding device includes a crude oil feed pipeline 50, which is connected to a desalting tank 52. The desalting tank 52 is connected to a flash tank 54 via a crude oil feed pipeline 53, and the flash tank 54 is connected to the primary distillation tower 1 via a crude oil feed pipeline 55. A crude oil feed pump 56 and a crude oil heating system 57 are installed on the crude oil feed pipeline 50. A crude oil feed pump 58 and a heater 59 are installed on the crude oil feed pipeline 53. A crude oil feed pump 60 is installed on the crude oil feed pipeline 55. The crude oil is fed into the desalting tank 52 for desalting and dehydration. The desalted and dehydrated crude oil... After flash distillation, the oil enters the primary distillation column 1. Further, the top of the flash tank 54 is connected to the secondary flash tank 61, and the bottom of the secondary flash tank 61 is connected to the naphtha separator feed buffer tank 39 via the secondary flash tank pipeline 62. The top of the secondary flash tank 61 is connected to a non-condensable gas pipeline 64. A feed pump 65 is installed on the secondary flash tank pipeline 62. In this embodiment, to reduce gas loss in the primary distillation column 1, a flash tank is added before the crude oil enters the primary distillation column 1 after being heated by a heat exchange network. The flash tank can be divided into two or more stages, and its operating pressure is higher than that of the primary distillation column 1, which can reduce the amount of non-condensable gas.

[0035] Example 4:

[0036] This embodiment describes atmospheric pressure tower 2 and vacuum pressure tower 3, specifically:

[0037] Atmospheric column 2 is connected to atmospheric stripper 66 via an atmospheric column side line. Atmospheric stripper 66 ensures the product quality and fractionation accuracy of atmospheric column 2, guarantees product quality and flash point, reduces the partial pressure of light components, and improves the crude oil extraction rate. Atmospheric stripper 66 is connected to atmospheric column 2 via an atmospheric column reflux side line. Steam is introduced into atmospheric stripper 66, providing power to it. One side of atmospheric stripper 66 is connected to an atmospheric pressure steam generator. The atmospheric stripping tower's outflow pipeline and the atmospheric stripping tower's outflow pipeline produce the corresponding products. In this embodiment, the atmospheric tower is connected to the atmospheric stripping tower 66 via atmospheric tower side line 1 67, atmospheric tower side line 2 68, and atmospheric tower side line 3 69. The atmospheric stripping tower 66 is connected to the atmospheric tower 2 via atmospheric tower reflux side line 1 70, atmospheric tower reflux side line 2 71, and atmospheric tower reflux side line 3 72. One side of the atmospheric stripping tower 66 is connected to an atmospheric stripping tower. Production pipeline 1 (73), atmospheric stripping tower production pipeline 2 (74), and atmospheric stripping tower production pipeline 3 (75) are all equipped with production pumps (76). Atmospheric stripping tower production pipeline 1 (73), atmospheric stripping tower production pipeline 2 (74), and atmospheric stripping tower production pipeline 3 (75) are all connected to production pumps (76). Atmospheric stripping tower production pipeline 1 (73) is connected to kerosene production pipeline 32 for kerosene production. Atmospheric stripping tower production pipeline 2 (74) produces light diesel oil. The third section 75 is used to extract heavy diesel oil; the middle section of one side of the atmospheric tower 2 is equipped with a first-stage circulating heat extraction 77 and a second-stage circulating heat extraction 96 to fully utilize the heat of the liquid phase in the middle section of the atmospheric tower 2; in this embodiment, the atmospheric tower 2 is equipped with three side-stream products and two middle-stage refluxes to evenly distribute the gas-liquid load of the entire tower and to optimize the heat exchange network of the entire device, recover the excess heat of the entire tower, and use it to heat crude oil and generate steam.

[0038] A condensate extraction device is installed at the top of the pressure reducing tower 3. The condensate extraction device includes a condensate buffer tank 78, which is connected to the top of the pressure reducing tower 3 via a top pipeline 79. A steam injection device 80 and a condenser 81 are installed on the top pipeline 79. The steam injection device 80 is used to create a vacuum, extract the gas at the top of the pressure reducing tower 3, and ensure the vacuum level at the top of the tower. A condensate extraction pipeline 82 is connected to the bottom of the condensate buffer tank 78. The gas phase at the top of the pressure reducing tower 4 is cooled by the condenser 81 and then enters the condensate buffer tank 78. Condensate oil and water are extracted from the bottom of the condensate buffer tank 78 through the condensate extraction pipeline 82.

[0039] One side of the vacuum distillation tower 3 is connected to the vacuum stripping tower 83 via a vacuum distillation tower side line 84. The vacuum stripping tower 83 is connected to the vacuum distillation tower 3 via a vacuum distillation tower reflux side line 85. Steam is introduced into the vacuum stripping tower 83. One side of the vacuum stripping tower 83 is connected to vacuum distillation tower side lines 86, 87, 88, and 89. The upper part of vacuum distillation tower side line 86 is connected to vacuum distillation tower side line 90 on the vacuum distillation tower 3, and the lower part of vacuum distillation tower side line 89 is connected to vacuum distillation tower side line 91 on the vacuum distillation tower 3. The bottom of the vacuum distillation tower 3 is connected to the vacuum residue oil extraction pipeline 92. The reducing side line 90, reducing side line 2 86, reducing side line 3 87, reducing side line 4 88, reducing side line 5 89, and reducing side line 6 91 are configured according to the different substances extracted from different crude oils. For example, for lubricating oil, different grades of lubricating oil mixtures are extracted, while for fuel oil, different grades of wax oil are used. One side of the vacuum distillation tower 3 is equipped with a first-stage circulating heat extraction system 93, a second-stage circulating heat extraction system 97, and a third-stage circulating heat extraction system 98 in the middle section of the vacuum distillation tower. The above-mentioned circulating heat extraction is used to utilize the heat of the liquid phase in the middle section of the vacuum distillation tower and reduce the amount of condensation at the top of the vacuum distillation tower.

[0040] Example 5:

[0041] This embodiment describes the intermediate section circulating heating device 4 of the primary distillation column, the reboiling device 5 of the primary distillation column, the bottom heating system 25 of the first negative pressure column, the crude oil heating system 57, and the bottom heating system 95 of the second negative pressure column. Specifically:

[0042] The intermediate section circulating heating unit 4 of the primary distillation column includes a main outlet pipeline 134 in the middle of the primary distillation column, which is connected to three branch pipelines in the middle of the primary distillation column: 135 (first branch pipeline), 136 (second branch pipeline), 137 (third branch pipeline), 138 (fourth branch pipeline), 139 (fifth branch pipeline), 140 (sixth branch pipeline), and 141 (seventh branch pipeline). 1. Connect the middle-section outflow branch line 8 (142) and the middle-section outflow branch line 9 (143) of the primary distillation column. Connect the middle-section outflow branch lines 1 (135), 2 (136), 3 (137), 4 (138), 5 (139), 6 (140), and 7 (141) of the primary distillation column. Line 8 (142) and the middle-section outflow branch line 9 (143) of the primary distillation column are respectively connected to the middle-section reflux main line 144 of the primary distillation column. The middle-section outflow branch lines 1 (135), 2 (136), 3 (137), 4 (138), 5 (139), 6 (140), and 7 (141) of the primary distillation column are also connected. The following heaters are installed on the primary distillation column middle section production line 8 (142) and the primary distillation column middle section production line 9 (143): primary distillation column middle section heater 1 (145), primary distillation column middle section heater 2 (146), primary distillation column middle section heater 3 (147), primary distillation column middle section heater 4 (148), primary distillation column middle section heater 5 (149), primary distillation column middle section heater 6 (150), primary distillation column middle section heater 7 (151), primary distillation column middle section heater 8 (152), and primary distillation column middle section heater 9 (153).

[0043] The primary distillation column reboiler unit 5 includes a main feed pipe 154 for the primary distillation column reboiler. This main feed pipe 154 is connected to several feed branch pipes 1-155, 156, 157, 158, 159, and 160 for the primary distillation column reboiler. The primary distillation column reboiler feed branch pipes 1-155, 156, 157, 158, 159, and 159 are connected to the primary distillation column reboiler feed branch pipes 1-155, 156, 157, 158, 159, and 159 of the primary distillation column reboiler. The reboiler feed branch pipe 160 is connected to the primary distillation column reboiler discharge main pipe 161. The primary distillation column reboiler discharge main pipe 161 is connected to the primary distillation column 1. Primary distillation column reboiler feed branch pipes 155, 2156, 3157, 4158, 5159, and 6167 are respectively installed on the primary distillation column reboiler feed branch pipes 160, 162, 163, 164, 165, 166, and 167.

[0044] The heating system 25 for the bottom of the negative pressure tower includes three heating pipelines: a first heating pipeline 115, a second heating pipeline 116, a third heating pipeline 117, and a fourth heating pipeline 118. These pipelines are connected to the second negative pressure tower 24. The first heating pipeline 115 is equipped with three heaters: a first heater 119, a second heater 120, and a third heater 121. The following are installed on the second 116: negative pressure tower heater 4 122, negative pressure tower heater 5 123, negative pressure tower heater 6 124, and negative pressure tower heater 7 125; the following are installed on the negative pressure tower heater pipeline 3 117: negative pressure tower heater 8 126, negative pressure tower heater 9 127, negative pressure tower heater 10 128, and negative pressure tower heater 11 129; the following are installed on the negative pressure tower heater pipeline 4 118: negative pressure tower heater 12 130, negative pressure tower heater 13 131, negative pressure tower heater 14 132, and negative pressure tower heater 15 133.

[0045] The crude oil heating system 57 includes crude oil pipeline 1 99, crude oil pipeline 2 100, crude oil pipeline 3 101, and crude oil pipeline 4 102. Crude oil pipelines 1 99, 2 100, 3 101, and 4 102 are connected to the desalting tank 52. Crude oil pipeline 1 99 is equipped with crude oil heaters 1 103 and 2 104; crude oil pipeline 2 100 is equipped with crude oil heaters 3 105, 4 106, 5 107, and 6 108; crude oil pipeline 3 101 is equipped with crude oil heaters 7 109, 8 110, and 9 111; and crude oil pipeline 4 102 is equipped with crude oil heaters 10 112, 11 113, and 114.

[0046] The heating system 95 for the second negative pressure tower includes a first negative pressure tower heating pipeline 168 and a second negative pressure tower heating pipeline 169. The first negative pressure tower heating pipeline 168 and the second negative pressure tower heating pipeline 169 are respectively connected to the atmospheric pressure heating furnace 36. The first negative pressure tower heating pipeline 168 is equipped with a first negative pressure tower heater 170, a second negative pressure tower heater 171, a third negative pressure tower heater 172, a fourth negative pressure tower heater 173, and a fifth negative pressure tower heater 174. The second negative pressure tower heating pipeline 169 is equipped with a sixth negative pressure tower heater 175, a seventh negative pressure tower heater 176, a eighth negative pressure tower heater 177, a ninth negative pressure tower heater 178, and a tenth negative pressure tower heater 179.

[0047] Example 6:

[0048] To further enhance energy efficiency, this embodiment describes the utilization of heat at the top of the primary distillation column 1, the top of the atmospheric distillation column 2, the top of the negative pressure column 16, the top of the negative pressure column 24, the middle section of the negative pressure column 24, and the middle section of the vacuum distillation column. This embodiment does not require the use of a heat pump for heat utilization, further enhancing energy efficiency. Specifically:

[0049] The crude oil heating system 57 is connected to the top of the primary distillation tower 1, the top of the atmospheric distillation tower 2, the top of the negative pressure tower 16, and the top of the negative pressure tower 24, respectively. The gas phase at the top of the primary distillation tower 1, the atmospheric distillation tower 2, the negative pressure tower 16, and the negative pressure tower 24 exchange heat with the crude oil in the crude oil heating system 57, providing heat for the crude oil heating system 57. The liquid phase from the middle section of the negative pressure tower 2 (circulating heat extraction 94) and the liquid phase from the first section of the depressurization tower (circulating heat extraction 93) exchange heat with the crude oil in the crude oil heating system 57, providing heat for the crude oil heating system 57.

[0050] The top of the primary distillation column 1 is connected to the crude oil heating system 57, which is connected to the primary distillation column top condenser 8. The vapor phase at the top of the primary distillation column 1 exchanges heat with the crude oil in the crude oil heating system 57, and then enters the primary distillation column top condenser 8 for further condensation. More specifically, the top of the primary distillation column 1 is connected to the crude oil heater 103, where the vapor phase at the top of the primary distillation column 1 exchanges heat with the crude oil in the crude oil heater 103, providing heat to the crude oil heater 103, and then enters the primary distillation column top condenser 8 for further condensation.

[0051] The top of atmospheric pressure tower 2 is connected to crude oil heating system 57, which in turn is connected to atmospheric pressure tower condenser 13. The gas phase at the top of atmospheric pressure tower 2 exchanges heat with the crude oil in crude oil heating system 57, and then enters atmospheric pressure tower condenser 13 for further condensation. Specifically, the top of atmospheric pressure tower 2 is connected to crude oil heater 112, where the gas phase exchanges heat with the crude oil in crude oil heater 112 to heat the crude oil heater 112. After the heat exchange, the gas phase enters atmospheric pressure tower condenser 13 for further condensation.

[0052] The top of the negative pressure tower 16 is connected to the crude oil heating system 57, which is connected to the negative pressure tower condenser 19. The gas phase at the top of the negative pressure tower 16 exchanges heat with the crude oil in the crude oil heating system 57, and then enters the negative pressure tower condenser 19 for further condensation. The top of the negative pressure tower 16 is also connected to the crude oil heater 107, where the gas phase exchanges heat with the crude oil in the crude oil heater 107, providing heat to the heater. After the heat exchange, the gas phase enters the negative pressure tower condenser 19 for further condensation.

[0053] The top of the second negative pressure tower 24 is connected to the crude oil heating system 57, which is connected to the condenser 28 of the second negative pressure tower. The gas phase at the top of the second negative pressure tower 24 exchanges heat with the crude oil in the crude oil heating system 57, and then enters the condenser 28 of the second negative pressure tower for further condensation. The top of the second negative pressure tower 24 is also connected to the third crude oil heater 105 and the seventh crude oil heater 109. The gas phase at the top of the second negative pressure tower 24 exchanges heat with the crude oil in the third crude oil heater 105 and the seventh crude oil heater 109, providing heat to the third crude oil heater 105 and the seventh crude oil heater 109, and then enters the condenser 28 of the second negative pressure tower for further condensation.

[0054] The intermediate section heat exchanger 94 of the second negative pressure tower is used to exchange heat between the liquid phase extracted from the intermediate section of the second negative pressure tower and the crude oil in the crude oil heating system 57. The liquid phase after heat exchange and cooling is returned to the second negative pressure tower 24. Specifically, the intermediate section heat exchanger 94 of the second negative pressure tower is used to exchange heat between the liquid phase extracted from the intermediate section of the second negative pressure tower and the crude oil heater 9 111 and the crude oil heater 6 108 in sequence. The liquid phase extracted from the intermediate section of the second negative pressure tower performs a first-stage heat exchange with the crude oil in the crude oil heater 9 111 and a second-stage heat exchange with the crude oil in the crude oil heater 6 108 to provide heat for the crude oil and make full use of the heat of the liquid phase in the intermediate section of the second negative pressure tower. The liquid phase after the second-stage heat exchange and cooling is returned to the second negative pressure tower 24.

[0055] The circulating heat extraction unit 93 in the middle section of the depressurization tower is used to exchange heat between the liquid phase extracted from the middle section of the depressurization tower and the crude oil in the crude oil heating system 57, providing heat to the crude oil. The liquid phase after heat exchange and cooling is returned to the depressurization tower 3. Specifically, the circulating heat extraction unit 93 in the middle section of the depressurization tower is used to exchange heat between the liquid phase extracted from the middle section of the depressurization tower and the crude oil heaters 104, 113, 110, and 106 in sequence. The liquid phase extracted from the middle section of the depressurization tower undergoes primary heat exchange with the crude oil in the crude oil heater 104, secondary heat exchange with the crude oil in the crude oil heater 113, tertiary heat exchange with the crude oil in the crude oil heater 110, and quaternary heat exchange with the crude oil in the crude oil heater 4, providing heat to the crude oil. The liquid phase after quaternary heat exchange and cooling is returned to the depressurization tower 3.

[0056] This embodiment makes full use of the gas phase at the top of the primary distillation column 1, the gas phase at the top of the atmospheric pressure column 2, the gas phase at the top of the negative pressure column 16, and the gas phase at the top of the negative pressure column 24; it also utilizes the heat from the liquid phase collected by the circulating heat extraction 94 in the middle section of the negative pressure column 2 and the heat from the liquid phase collected by the circulating heat extraction 93 in the first section of the middle section of the depressurization column, thus saving energy and further achieving the effect of energy saving.

[0057] Example 7:

[0058] This embodiment describes the heat utilization of the atmospheric stripping tower outflow pipeline 1 (73), atmospheric stripping tower outflow pipeline 2 (74), atmospheric stripping tower outflow pipeline 3 (75), atmospheric stripping tower middle section first-stage circulating heat extraction (77), and atmospheric stripping tower middle section second-stage circulating heat extraction (96). This embodiment does not require the use of a heat pump, further achieving energy-saving effects. Specifically:

[0059] The atmospheric stripping tower outlet pipeline 73 is sequentially connected to the negative pressure tower bottom heating system 25 and the primary distillation tower mid-section circulating heating device 4. The material collected from the atmospheric stripping tower outlet pipeline 73 enters the negative pressure tower bottom heating system 25, serving as a heat source for primary heat exchange with the material in the negative pressure tower bottom. After primary heat exchange, it enters the primary distillation tower mid-section circulating heating device 4, serving as a heat source for secondary heat exchange with the circulating material in the primary distillation tower mid-section. After secondary heat exchange, kerosene is collected through the atmospheric stripping tower outlet pipeline 73, thus fully utilizing the atmospheric stripping tower outlet pipeline 73. The heat of the extracted material; more specifically, the atmospheric stripping tower extraction pipeline 73 is sequentially connected to the negative pressure tower heater 12 130 and the primary distillation tower middle heater 145. The material extracted from the atmospheric stripping tower extraction pipeline 73 undergoes primary heat exchange with the negative pressure tower heater 12 130 to provide heat to the negative pressure tower heater 12 130. After the primary heat exchange, it undergoes secondary heat exchange with the primary distillation tower middle heater 145 to provide heat to the primary distillation tower middle heater 145. After the secondary heat exchange, kerosene is extracted through the atmospheric stripping tower extraction pipeline 73.

[0060] The atmospheric stripping tower outlet pipeline 2.74 is sequentially connected to the bottom heating system 25 of the negative pressure tower and the feedstock heater 43 of the naphtha fractionation tower. The material collected from the atmospheric stripping tower outlet pipeline 2.74 enters the bottom heating system 25 of the negative pressure tower, serving as a heat source for primary heat exchange with the material in the bottom of the negative pressure tower. After primary heat exchange, it enters the feedstock heater 43 of the naphtha fractionation tower, serving as a heat source for secondary heat exchange with the naphtha. After secondary heat exchange, light diesel oil is collected through the atmospheric stripping tower outlet pipeline 2.74, fully utilizing the heat generated by the atmospheric stripping tower outlet pipeline 2.74. The material's heat; specifically, the atmospheric stripping tower outlet pipeline 2 74 is sequentially connected to the negative pressure tower heater 14 132 and the naphtha fractionation tower feedstock heater 43. The material extracted from the atmospheric stripping tower outlet pipeline 2 74 undergoes a primary heat exchange with the negative pressure tower heater 14 132 to provide heat to the negative pressure tower heater 14 132. After the primary heat exchange, it undergoes a secondary heat exchange with the naphtha fractionation tower feedstock heater 43 to provide heat to the naphtha fractionation tower feedstock heater 43. After the secondary heat exchange, light diesel oil is extracted through the atmospheric stripping tower outlet pipeline 2 74.

[0061] The atmospheric stripping tower outlet pipeline 3.75 is connected to the bottom heating system 25 of the negative pressure tower, the reboiler unit 5 of the primary distillation tower, and the circulating heating device 4 of the middle section of the primary distillation tower in sequence. The material collected from the atmospheric stripping tower outlet pipeline 3.75 enters the bottom heating system 25 of the negative pressure tower as a heat source for primary heat exchange with the material in the bottom of the negative pressure tower. After primary heat exchange, it enters the reboiler unit 5 of the primary distillation tower as a heat source for secondary heat exchange with the material in the bottom of the primary distillation tower. After secondary heat exchange, it enters the circulating heating device 4 of the middle section of the primary distillation tower as a heat source for tertiary heat exchange with the circulating material in the middle section of the primary distillation tower. After tertiary heat exchange, heavy diesel oil is collected through the atmospheric stripping tower outlet pipeline 3.75, making full use of the atmospheric stripping tower outlet pipeline 3.75. 5. Heat of the extracted material; Specifically, the atmospheric stripping tower extraction pipeline 3.75 is sequentially connected to the negative pressure tower heater 7.125, the primary distillation tower reboiler 3.164, and the primary distillation tower intermediate heater 8.152. The material extracted from the atmospheric stripping tower extraction pipeline 3.75 undergoes primary heat exchange with the negative pressure tower heater 7.125 to provide heat to the negative pressure tower heater 7.125. After the primary heat exchange, it undergoes secondary heat exchange with the primary distillation tower reboiler 3.164 to provide heat to the primary distillation tower reboiler 3.164. After the secondary heat exchange, it undergoes tertiary heat exchange with the primary distillation tower intermediate heater 8.152 to provide heat to the primary distillation tower intermediate heater 8.152. After the tertiary heat exchange, heavy diesel oil is extracted through the atmospheric stripping tower extraction pipeline 3.75.

[0062] The circulating heat extraction unit 77 in the middle section of the atmospheric distillation column is used to exchange heat sequentially with the reboiler unit 5 of the primary distillation column, the reboiler system 25 of the negative pressure column, and the reboiler 51 of the separation column. The liquid phase from the middle section of the atmospheric distillation column enters the reboiler unit 5 of the primary distillation column as a heat source for primary distillation column reboiler material for primary distillation column reboiler material. After primary heat exchange, it enters the reboiler system 25 of the negative pressure column as a heat source for secondary heat exchange with the reboiler material of the negative pressure column. After secondary heat exchange, it enters the reboiler 51 of the separation column as a heat source for tertiary heat exchange with the reboiler material of the separation column. After cooling following tertiary heat exchange, it returns to the atmospheric distillation column 2. This fully utilizes the heat from the middle section of the atmospheric distillation column, saving energy and reducing the condensation at the top of the atmospheric distillation column 2. Specifically, the circulating heat extraction unit 77 in the middle section of the atmospheric distillation column is used to exchange heat sequentially with the reboiler unit 5 of the primary distillation column, the reboiler system 25 of the negative pressure column, and the reboiler 51 of the separation column. The liquid phase collected from the first stage of the atmospheric distillation column exchanges heat sequentially with the reboiler 162 of the primary distillation column, the heater 126 of the negative pressure column, the heater 119 of the negative pressure column, and the reboiler 51 of the separation column. The liquid phase collected from the first stage of the atmospheric distillation column exchanges heat with the reboiler 162 of the primary distillation column in a primary heat exchange, providing heat to the reboiler 162. After the primary heat exchange, it exchanges heat with the heater 126 of the negative pressure column in a secondary heat exchange, providing heat to the heater 126. After the secondary heat exchange, it exchanges heat with the heater 119 of the negative pressure column in a secondary heat exchange, providing heat to the heater 119. After the secondary heat exchange, it exchanges heat with the reboiler 51 of the separation column in a tertiary heat exchange, providing heat to the reboiler 51 of the separation column. After cooling by the tertiary heat exchange, it returns to the atmospheric distillation column 2. This fully utilizes the heat from the first stage of the atmospheric distillation column, saving energy and reducing the amount of condensate at the top of the atmospheric distillation column 2.

[0063] The second-stage circulating heat extraction unit 96 in the middle section of the atmospheric distillation column is used to exchange heat between the liquid phase collected from the second stage of the atmospheric distillation column and the heating system 95 of the bottom of the negative pressure column and the circulating heating device 4 in the middle section of the primary distillation column. The liquid phase collected from the second stage of the atmospheric distillation column enters the heating system 95 of the bottom of the negative pressure column, serving as both material and heat source for the bottom of the negative pressure column, undergoing primary heat exchange. After primary heat exchange, it enters the circulating heating device 4 in the middle section of the primary distillation column, serving as a heat source for secondary heat exchange with the circulating material in the middle section of the primary distillation column. The liquid phase cooled after secondary heat exchange returns to the atmospheric distillation column 2, fully utilizing the heat from the second-stage circulating heat extraction unit 96 in the middle section of the atmospheric distillation column, further saving energy while reducing the amount of condensate at the top of the atmospheric distillation column 2. Specifically, the atmospheric distillation column... The intermediate section two-stage circulating heat extraction 96 is used to sequentially exchange heat between the liquid phase collected from the intermediate section two of the atmospheric pressure tower and the heaters nine 178 and two 171 of the negative pressure tower, as well as the intermediate heater six 150 of the primary distillation tower. The liquid phase collected from the intermediate section two of the atmospheric pressure tower undergoes a primary heat exchange with the heater nine 178 of the negative pressure tower to provide heat to the heater nine 178. After the primary heat exchange, it undergoes a secondary heat exchange with the heater two 171 of the negative pressure tower to provide heat to the heater two 171. After the secondary heat exchange, it undergoes a secondary heat exchange with the intermediate heater six 150 of the primary distillation tower to provide heat to the heater six 150. The liquid phase cooled by the secondary heat exchange is returned to the atmospheric pressure tower 2.

[0064] Example 8:

[0065] This embodiment describes the heat utilization of the second-stage circulating heat extraction in the middle section of the pressure reducing tower (97), the third-stage circulating heat extraction in the middle section of the pressure reducing tower (98), and the heat utilization of the pressure reducing tower bottom, the third side line, the fourth side line, the fifth side line, and the sixth side line. The heat utilization in this embodiment does not require the use of a heat pump, further achieving energy-saving effects. Specifically:

[0066] The second-stage circulating heat extraction unit 97 in the middle section of the vacuum distillation tower is used to sequentially exchange heat with the reboiler heating system 25 of the first-stage negative pressure tower, the reboiler heating system 95 of the second-stage negative pressure tower, the reboiler unit 5 of the primary distillation tower, and the circulating heating device 4 in the middle section of the primary distillation tower. The liquid phase collected in the second-stage middle section of the vacuum distillation tower enters the reboiler heating system 25 of the first-stage negative pressure tower as a heat source for primary heat exchange with the material in the reboiler of the first-stage negative pressure tower. After primary heat exchange, it enters the reboiler heating system 95 of the second-stage negative pressure tower as both material and heat source for the reboiler of the second-stage negative pressure tower. The liquid undergoes two-stage heat exchange, then enters the reboiler 5 of the primary distillation column as a heat source for the material in the bottom of the primary distillation column. It then undergoes a third-stage heat exchange, followed by a fourth-stage heat exchange with the circulating heating unit 4 in the middle section of the primary distillation column. After cooling following the fourth-stage heat exchange, the liquid returns to the vacuum distillation column 3. More specifically, the second-stage circulating heat extractor 97 in the middle section of the vacuum distillation column is used to combine the liquid phase extracted from the second stage of the middle section with heaters 124, 3121, and 6 of the first and second vacuum distillation columns. Heaters 175, 170, 163, and 151 in the middle section of the primary distillation column sequentially exchange heat. The liquid phase collected in the second section of the middle section of the vacuum distillation column undergoes a first-stage heat exchange with heater 6 124 in the first-stage vacuum distillation column, providing heat to heater 6 124. After the first-stage heat exchange, it undergoes a second-stage heat exchange with heater 3 121 in the first-stage vacuum distillation column, providing heat to heater 3 121. After the second-stage heat exchange, it undergoes a second-stage heat exchange with heater 6 175 in the second-stage vacuum distillation column. The heat exchange provides heat to heater 6175 of the second negative pressure tower. After the first heat exchange, it undergoes a second heat exchange with heater 1170 of the second negative pressure tower to provide heat to heater 1170 of the second negative pressure tower. After the second heat exchange, it undergoes a third heat exchange with reboiler 2163 of the primary distillation tower to provide heat to reboiler 2163 of the primary distillation tower. After the third heat exchange, it undergoes a fourth heat exchange with heater 7151 in the middle of the primary distillation tower to provide heat to heater 7151 in the middle of the primary distillation tower. The liquid phase cooled by the fourth heat exchange is returned to the vacuum tower 3.

[0067] The three-stage circulating heat extraction system 98 in the middle section of the pressure reducing tower is used to sequentially exchange heat between the liquid phase collected from the third stage of the middle section of the pressure reducing tower and the heating system 95 of the bottom of the second negative pressure tower. The liquid phase collected from the third stage of the middle section of the pressure reducing tower enters the heating system 95 of the bottom of the second negative pressure tower as material and heat source for the bottom of the second negative pressure tower 24, and undergoes primary heat exchange. The liquid phase after heat exchange and cooling returns to the pressure reducing tower 3. Specifically, the three-stage circulating heat extraction system 98 in the middle section of the pressure reducing tower is used to sequentially exchange heat between the liquid phase collected from the third stage of the middle section of the pressure reducing tower and the heaters 173 and 176 of the second negative pressure tower. The liquid phase collected from the third stage of the middle section of the pressure reducing tower undergoes primary heat exchange with the heater 173 of the second negative pressure tower, providing heat to the heater 173. After primary heat exchange, it undergoes primary secondary heat exchange with the heater 176 of the second negative pressure tower. The liquid phase after primary secondary heat exchange and cooling returns to the pressure reducing tower 3.

[0068] The vacuum residue oil extraction pipeline 92 of the vacuum distillation tower bottom is sequentially connected to the bottom heating system 95 of the second vacuum distillation tower, the reboiler unit 5 of the primary distillation tower, the bottom heating system 25 of the first vacuum distillation tower, the intermediate circulation heating device 4 of the primary distillation tower, and the crude oil heating system 57. The material extracted from the vacuum residue oil extraction pipeline 92 enters the bottom heating system 95 of the second vacuum distillation tower, serving as the bottom material and heat source for the second vacuum distillation tower 24, undergoing primary heat exchange. After primary heat exchange, it enters the reboiler unit 5 of the primary distillation tower, serving as the heat source and bottom material for the primary distillation tower, undergoing secondary heat exchange. After secondary heat exchange, it enters the bottom heating system 25 of the first vacuum distillation tower, serving as the heat source and bottom material for the first vacuum distillation tower, undergoing tertiary heat exchange. After tertiary heat exchange, it enters the intermediate circulation heating device 4 of the primary distillation tower, serving as... The material circulating in the middle section of the primary distillation tower undergoes four stages of heat exchange as a heat source. After the fourth stage of heat exchange, it enters the crude oil heating system 57, where it undergoes a fifth stage of heat exchange with the crude oil. After the fifth stage of heat exchange, vacuum residue is extracted through the vacuum residue extraction pipeline 92. More specifically, the vacuum residue extraction pipeline 92 is sequentially connected to the following heaters: vacuum tower 2 heater 5 (174), vacuum tower 2 heater 10 (179), primary distillation tower reboiler 5 (166), vacuum tower 1st heater 15 (133), vacuum tower 1st heater 11 (129), vacuum tower 1st heater 5 (123), vacuum tower 1st heater 2 (120), primary distillation tower middle section heater 4 (148), and crude oil heater 12 (114). The material extracted from the vacuum residue extraction pipeline 92 is then exchanged with the material from the vacuum tower 2 heater... Heater 5174 performs a primary heat exchange to provide heat to heater 5174 of the second negative pressure tower. After the primary heat exchange, it performs a primary secondary heat exchange with heater 10179 of the second negative pressure tower to provide heat to heater 10179. After the primary secondary heat exchange, it performs a secondary heat exchange with reboiler 5166 of the primary distillation tower to provide heat to reboiler 5166. After the secondary heat exchange, it performs a tertiary primary heat exchange with heater 15133 of the first negative pressure tower to provide heat to heater 15133. After the tertiary primary heat exchange, it performs a tertiary secondary heat exchange with heater 11129 of the first negative pressure tower to provide heat to heater 11129. After the tertiary secondary heat exchange, heater 5123 of the first negative pressure tower... The system undergoes a three-stage, three-stage heat exchange to provide heat to heater 5123 in the first negative pressure tower. After the three-stage, three-stage heat exchange, it undergoes a three-stage, four-stage heat exchange with heater 2120 in the first negative pressure tower to provide heat to heater 2120. After the three-stage, four-stage heat exchange, it undergoes a four-stage heat exchange with heater 4148 in the middle of the primary distillation tower to provide heat to heater 4148. After the four-stage heat exchange, it enters crude oil heater 12114 and undergoes a five-stage heat exchange with the crude oil in crude oil heater 12114 to provide heat to crude oil heater 12114. After the five-stage heat exchange, the vacuum residue is extracted through vacuum residue extraction pipeline 92. The bottom heating system 95 of the second negative pressure tower undergoes two heat exchanges, and the bottom heating system 25 of the first negative pressure tower undergoes four heat exchanges.

[0069] The reduced pressure column side line 87 is sequentially connected to the bottom heating system 25 of the negative pressure tower and the circulating heating device 4 in the middle section of the primary distillation tower. The material collected from the reduced pressure column side line 87 enters the bottom heating system 25 of the negative pressure tower as a heat source and undergoes primary heat exchange with the material in the bottom of the negative pressure tower 16. After the primary heat exchange, it enters the circulating heating device 4 in the middle section of the primary distillation tower as a heat source and undergoes secondary heat exchange with the circulating material in the middle section of the primary distillation tower. After the secondary heat exchange, the reduced pressure column oil is collected through the reduced pressure column side line 87. Specifically, the reduced pressure column side line 87 is sequentially connected to the heater 127 of the negative pressure tower and the heater 149 in the middle section of the primary distillation tower. The material collected from the reduced pressure column side line 87 undergoes primary heat exchange with the heater 127 of the negative pressure tower to provide heat for the heater 127. After the primary heat exchange, it undergoes secondary heat exchange with the heater 149 in the middle section of the primary distillation tower to provide heat for the heater 149. After the secondary heat exchange, the reduced pressure column oil is collected through the reduced pressure column side line 87.

[0070] The reduced pressure distillation column side line 88 is sequentially connected to the bottom heating system 25 of the negative pressure tower, the reboiler unit 5 of the primary distillation column, and the circulating heating unit 4 of the middle section of the primary distillation column. The material collected from the reduced pressure distillation column side line 88 enters the bottom heating system 25 of the negative pressure tower, serving as a heat source and undergoing primary heat exchange with the material in the bottom of the negative pressure tower 16. After primary heat exchange, it enters the reboiler unit 5 of the primary distillation column, serving as both the material in the bottom of the primary distillation column and a heat source, undergoing secondary heat exchange. After secondary heat exchange, it enters the circulating heating unit 4 of the middle section of the primary distillation column, serving as a heat source and undergoing tertiary heat exchange with the circulating material in the middle section of the primary distillation column. After tertiary heat exchange, the reduced pressure distillation column oil is collected through the reduced pressure distillation column side line 88. Specifically... The reduced pressure tower side line 88 is sequentially connected to the negative pressure tower heater 4 122, the primary distillation tower reboiler 6 167, and the primary distillation tower middle heater 9 153. The material collected from the reduced pressure tower side line 88 undergoes primary heat exchange with the negative pressure tower heater 4 122 to provide heat to the negative pressure tower heater 4 122. After the primary heat exchange, it undergoes secondary heat exchange with the primary distillation tower reboiler 6 167 to provide heat to the primary distillation tower reboiler 6 167. After the secondary heat exchange, it undergoes tertiary heat exchange with the primary distillation tower middle heater 9 163 to provide heat to the primary distillation tower middle heater 9 163. After the tertiary heat exchange, the reduced pressure tower oil is collected through the reduced pressure tower side line 88.

[0071] The fifth-stage heat exchanger (89) is sequentially connected to the heating system 95 of the second negative pressure tower, the heating system 25 of the first negative pressure tower, and the circulating heating device 4 in the middle section of the primary distillation tower. The material collected from the fifth-stage heat exchanger (89) enters the heating system 95 of the second negative pressure tower, serving as a heat source for primary heat exchange with the material in the bottom of the second negative pressure tower (24). After primary heat exchange, it enters the heating system 25 of the first negative pressure tower, serving as a heat source for secondary heat exchange with the material in the bottom of the first negative pressure tower (16). After secondary heat exchange, it enters the circulating heating device 4 in the middle section of the primary distillation tower, serving as a heat source for tertiary heat exchange with the circulating material in the middle section of the primary distillation tower. After tertiary heat exchange, the fifth-stage heat exchanger oil is collected through the fifth-stage heat exchanger (89). The material is connected in sequence to the third heater 172 of the second negative pressure tower, the thirteenth heater 131 of the first negative pressure tower, and the second heater 146 of the middle section of the primary distillation tower. The material collected from the fifth-pressure side line 89 undergoes a first-stage heat exchange with the third heater 172 of the second negative pressure tower to provide heat for the second negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the thirteenth heater 131 of the first negative pressure tower to provide heat for the first negative pressure tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the second heater 146 of the middle section of the primary distillation tower to provide heat for the middle section of the primary distillation tower. After the third-stage heat exchange, the fifth-pressure oil is collected through the fifth-pressure side line 89.

[0072] The reduced-pressure VI side stream 91 is sequentially connected to the heating system 95 of the second tower of the negative pressure tower, the reboiler 5 of the primary distillation tower, the heating system 25 of the first tower of the negative pressure tower, and the circulating heating device 4 of the middle section of the primary distillation tower. The material collected from the reduced-pressure VI side stream 91 enters the heating system 95 of the second tower of the negative pressure tower, serving as a heat source for primary heat exchange with the material in the reboiler of the second tower of the negative pressure tower (24). After primary heat exchange, it enters the reboiler 5 of the primary distillation tower, serving as a heat source for secondary heat exchange with the material in the reboiler of the primary distillation tower. After secondary heat exchange, it enters the heating system 25 of the first tower of the negative pressure tower, serving as a heat source for tertiary heat exchange with the material in the reboiler of the first tower of the negative pressure tower (16). After tertiary heat exchange, it enters the circulating heating device 4 of the middle section of the primary distillation tower, serving as a heat source for quaternary heat exchange with the circulating material in the middle section of the primary distillation tower. After quaternary heat exchange, the reduced-pressure VI oil is collected through the reduced-pressure VI side stream 91. The structure consists of: the reduced pressure column side line 91 connected in sequence to the second heater 8 177 of the negative pressure tower, the reboiler 4 165 of the primary distillation tower, the first heater 10 128 of the negative pressure tower, and the middle heater 3 147 of the primary distillation tower. The material collected from the reduced pressure column side line 91 undergoes a first-stage heat exchange with the second heater 8 177 of the negative pressure tower to provide heat for the second heater 8 177. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the fourth heater 4 165 of the primary distillation tower to provide heat for the fourth heater 4 165. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the first heater 10 128 of the negative pressure tower to provide heat for the first heater 10 128. After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the middle heater 3 147 of the primary distillation tower to provide heat for the middle heater 3 147 of the primary distillation tower. After the fourth-stage heat exchange, the reduced pressure column oil is collected through the reduced pressure column side line 91.

[0073] Example 9:

[0074] This embodiment provides a distillation method for an energy-saving atmospheric and vacuum distillation apparatus with five columns, comprising the following steps:

[0075] S1: After desalting and dehydrating, the crude oil is heated, and the heated material enters the primary distillation tower; preferably, in S1, after desalting, dehydrating, and heating, the crude oil undergoes flash evaporation in flash tank 54 before entering primary distillation tower 1. The liquid phase after flash evaporation enters primary distillation tower 1, and the gas phase after flash evaporation is condensed by a condenser and then enters secondary flash tank 61 for secondary flash evaporation. The gas phase after secondary flash evaporation is collected through non-condensable gas pipeline 64, and the liquid phase after secondary flash evaporation enters the naphtha separation unit for naphtha extraction; S2: The top reflux device at the top of the primary distillation tower extracts the top gas and light gasoline from the primary distillation tower, and the light gasoline enters the naphtha separation unit. The separation unit extracts naphtha; S3: The bottom oil from the primary distillation column 1 enters the negative pressure column 16. The vapor phase at the top of the negative pressure column 16 is partially refluxed back to the negative pressure column 16 after condensation, and partially undergoes naphtha separation; more specifically, a portion enters the naphtha separation unit for naphtha separation; S4: The material at the bottom of the negative pressure column 16 is heated and enters the negative pressure column 24. The vapor phase at the top of the negative pressure column 24 is partially refluxed back to the negative pressure column 24 after condensation, and partially undergoes naphtha separation; more specifically, a portion enters the naphtha separation unit for naphtha separation; more preferably, in S4, the negative pressure column 24... 4. Kerosene is extracted from the negative pressure stripping tower 31 on one side after steam stripping; S5: The bottom oil from the bottom of the negative pressure tower 24 is heated and enters the atmospheric pressure tower 2. The vapor phase at the top of the atmospheric pressure tower 2 is condensed and refluxed back to the atmospheric pressure tower 2. The atmospheric pressure tower 2 is connected to the atmospheric pressure stripping tower 66. Different components of finished oil are extracted from the side stream of the atmospheric pressure stripping tower 66; More specifically, in S5, the atmospheric pressure stripping tower 66 is provided with three side streams, namely atmospheric pressure stripping tower extraction pipeline 1 73, atmospheric pressure stripping tower extraction pipeline 2 74, and atmospheric pressure stripping tower extraction pipeline 3 75. After stripping with stripping steam, the atmospheric pressure stripping tower 66 extracts kerosene, light diesel oil, and heavy diesel oil respectively. Diesel fuel; S6: The bottom oil from atmospheric pressure tower 2 is heated and then enters vacuum tower 3. The steam injection device 80 at the top of vacuum tower 3 extracts the top gas of vacuum tower 3 and maintains the vacuum at the top of the tower. Condensed oil and water are collected from the top of vacuum tower 3; S7: Sludge oil is collected from the bottom of vacuum tower 3. Vacuum tower 3 is connected to vacuum stripping tower 83. The side streams of vacuum tower 3 and vacuum stripping tower 83 collect the corresponding oil products from each line of vacuum tower; More specifically, the side stream of vacuum tower 3 is used to collect vacuum line 1 oil and vacuum line 6 oil, and the side stream of vacuum stripping tower 83 is stripped by stripping steam to collect vacuum line 2 oil, vacuum line 3 oil, vacuum line 4 oil and vacuum line 5 oil respectively.

[0076] Example 10:

[0077] This embodiment utilizes heat, specifically:

[0078] The vapor phase from the top of the primary distillation tower 1, the vapor phase from the top of the atmospheric distillation tower 2, the vapor phase from the top of the negative pressure tower 16, the vapor phase from the top of the negative pressure tower 24, the liquid phase refluxed from the middle section of the negative pressure tower 2, and the liquid phase refluxed from the middle section of the vacuum distillation tower 1 are used to exchange heat with the crude oil in the crude oil heating system 57, providing heat for the crude oil heating system 57.

[0079] The material collected from the atmospheric stripping tower outlet pipeline 73 undergoes primary heat exchange with the reboiler heating system 25 of the negative pressure tower, providing heat for the reboiler heating system 25. After the primary heat exchange, it undergoes secondary heat exchange with the intermediate circulation heating device 4 of the primary distillation tower, providing heat for the intermediate circulation heating device 4. After the secondary heat exchange, kerosene is collected through the atmospheric stripping tower outlet pipeline 73. The material collected from the atmospheric stripping tower outlet pipeline 74 undergoes primary heat exchange with the reboiler heating system 25 of the negative pressure tower, providing heat for the reboiler of the negative pressure tower. System 25 provides heat, and after the first-stage heat exchange, it undergoes a second-stage heat exchange with the naphtha fractionation tower feedstock heater 43 to provide heat for the naphtha fractionation tower feedstock heater 43. After the second-stage heat exchange, light diesel oil is extracted through the atmospheric stripping tower outlet pipeline 24. The material extracted through the atmospheric stripping tower outlet pipeline 35 undergoes a first-stage heat exchange with the negative pressure tower reboiler heating system 25 to provide heat for the negative pressure tower reboiler heating system 25. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the primary distillation tower reboiler unit 5 to provide heat for the primary distillation tower reboiler unit 5. After the secondary heat exchange, a tertiary heat exchange is performed with the intermediate section circulating heating device 4 of the primary distillation column to provide heat for the intermediate section circulating heating device 4. After the tertiary heat exchange, heavy diesel oil is extracted through the atmospheric stripping tower outlet pipeline 75. The liquid phase of the intermediate section of the atmospheric distillation column is extracted through the circulating heat extraction 77 and performs a primary heat exchange with the reboiler device 5 of the primary distillation column to provide heat for the reboiler device 5. After the primary heat exchange, a secondary heat exchange is performed with the bottom heating system 25 of the negative pressure tower to provide heat for the negative pressure tower. After heat exchange, the liquid phase from the second stage of the atmospheric distillation tower undergoes a three-stage heat exchange with the reboiler 51 of the separation tower to provide heat to the reboiler 51. After cooling through the three-stage heat exchange, it returns to the atmospheric distillation tower 2. The liquid phase from the second stage of the atmospheric distillation tower, collected by the second stage circulating heat extraction 96, undergoes a first-stage heat exchange with the reboiler heating system 95 of the second stage of the negative pressure tower to provide heat to the reboiler heating system 95. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the circulating heating device 4 of the middle stage of the primary distillation tower to provide heat to the circulating heating device 4 of the middle stage of the primary distillation tower. After cooling through the second-stage heat exchange, it returns to the atmospheric distillation tower 2.

[0080] The liquid phase from the first stage of the middle section of the vacuum distillation tower (93) undergoes a primary heat exchange with the heating system 25 of the first reboiler of the negative pressure tower, providing heat to the system. After the primary heat exchange, it undergoes a secondary heat exchange with the heating system 95 of the second reboiler of the negative pressure tower, providing heat to the system. After the secondary heat exchange, it undergoes a tertiary heat exchange with the reboiler 5 of the primary distillation tower, providing heat to the reboiler 5. After the tertiary heat exchange, it undergoes a quaternary heat exchange with the circulating heating device 4 in the middle section of the primary distillation tower, providing heat to the circulating heating device 4 in the middle section of the primary distillation tower. After cooling following the quaternary heat exchange, the liquid phase returns to the vacuum distillation tower 3. The liquid phase from the third stage of the middle section of the vacuum distillation tower (98) undergoes a primary heat exchange with the heating system 25 of the first reboiler of the negative pressure tower. The material from the vacuum residue oil production pipeline 92 undergoes a first-stage heat exchange with the second-stage vacuum tower reboiler heating system 95, providing heat to the system. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the primary distillation tower reboiler 5, providing heat to the reboiler. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the first-stage vacuum tower reboiler heating system 25, providing heat to the primary distillation tower reboiler. After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the primary distillation tower mid-section circulating heating device 4, providing heat to the primary distillation tower mid-section circulating heating device 4. After the fourth-stage heat exchange, it enters the crude oil heating system 57 to heat the crude oil. The crude oil in system 57 undergoes five-stage heat exchange. After the five-stage heat exchange, vacuum residue oil is extracted through vacuum residue extraction pipeline 92. The material extracted from the third vacuum residue side line 87 undergoes a first-stage heat exchange with the bottom heating system 25 of the first vacuum distillation tower, providing heat to the system. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the intermediate circulation heating device 4 of the primary distillation tower, providing heat to the device. After the second-stage heat exchange, the third vacuum residue oil is extracted through the third vacuum residue side line 87. The material extracted from the fourth vacuum residue side line 88 undergoes a first-stage heat exchange with the bottom heating system 25 of the first vacuum distillation tower, providing heat to the system. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiler device 5 of the primary distillation tower, providing heat to the reboiler device 5 of the primary distillation tower. Unit 5 provides heat, and after secondary heat exchange, it undergoes tertiary heat exchange with the circulating heating unit 4 in the middle section of the primary distillation tower to provide heat for the circulating heating unit 4 in the middle section of the primary distillation tower. After tertiary heat exchange, the reduced-pressure oil is collected through the reduced-pressure oil side line 88. The material collected from the reduced-pressure oil side line 89 undergoes primary heat exchange with the heating system 95 of the second tower of the negative pressure tower to provide heat for the second tower of the negative pressure tower. After primary heat exchange, it undergoes secondary heat exchange with the heating system 25 of the first tower of the negative pressure tower to provide heat for the first tower of the negative pressure tower. After secondary heat exchange, it undergoes tertiary heat exchange with the circulating heating unit 4 in the middle section of the primary distillation tower to provide heat for the circulating heating unit 4 in the middle section of the primary distillation tower. After tertiary heat exchange, the reduced-pressure oil is collected through the reduced-pressure oil side line 89.The material collected from the reduced-pressure distillation column side stream 91 undergoes a primary heat exchange with the heating system 95 of the second reboiler of the negative pressure tower, providing heat to the system. After the primary heat exchange, it undergoes a secondary heat exchange with the reboiler unit 5 of the primary distillation column, providing heat to the circulating heating unit 4 in the middle section of the primary distillation column. After the secondary heat exchange, it undergoes a tertiary heat exchange with the heating system 25 of the first reboiler of the negative pressure tower, providing heat to the system. After the tertiary heat exchange, it undergoes a quaternary heat exchange with the circulating heating unit 4 in the middle section of the primary distillation column, providing heat to the circulating heating unit 4 in the middle section of the primary distillation column. After the quaternary heat exchange, the reduced-pressure distillation column oil is collected through the reduced-pressure distillation column side stream 91.

[0081] Taking an 8 million tons / year atmospheric and vacuum distillation unit in an oil refinery as an example, under the same throughput and total extraction rate, the heat load of the atmospheric furnace in the traditional process is 69.9 MW, and the heat load of the vacuum furnace is 28.5 MW. After adopting the present invention, the heat load of the atmospheric furnace is 59.2 MW, the heat load of the vacuum furnace is 30.0 MW, and the total heat load of the heating furnace is reduced by about 9%, which plays a role in energy saving.

[0082] In summary, due to the adoption of the above technical solution, this application has the following advantages: 1. All gasoline components and part of the kerosene components of crude oil are extracted before entering the atmospheric distillation tower, reducing energy consumption, improving heat utilization, and improving crude oil separation accuracy; 2. Adding two negative pressure towers between the primary distillation tower and the atmospheric distillation tower can promptly separate the vaporized gasoline and kerosene components, reducing the irreversibility of heating and cooling, and achieving energy saving; moreover, the two negative pressure towers operate under negative pressure, reducing the operating temperature inside the negative pressure towers, which is beneficial to the utilization of low-grade heat in the system; 3. The two negative pressure towers will... 4. The extraction of all gasoline components and part of the kerosene components reduces the amount of material entering the atmospheric pressure heater, lowers the load on the atmospheric pressure heater, directly reduces the fuel oil consumption of the unit, and further achieves the goal of energy saving; 5. The operating pressure of the primary distillation tower is reduced to between slightly positive and slightly negative pressure, increasing the circulating heating in the middle section of the primary distillation tower, reducing the heat grade required by the primary distillation tower, and increasing energy utilization efficiency; 6. A flash tank is added before the primary distillation tower after the crude oil is heated by the heat exchange network. The flash tank can be divided into two or more stages. The operating pressure of the flash tank is higher than that of the primary distillation tower, which can reduce the amount of non-condensable gas and reduce gas loss in the primary distillation tower.

[0083] The devices and connections not specifically described above are all prior art, and will not be described in detail here.

[0084] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0085] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the various possible combinations in this application will not be described separately.

[0086] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, and such combinations should also be regarded as the content disclosed in this application.

Claims

1. An energy-saving atmospheric and vacuum five-tower distillation apparatus, comprising a primary distillation tower (1), an atmospheric distillation tower (2), and a vacuum distillation tower (3), wherein a primary distillation tower reboiler (5) is provided at the bottom of the primary distillation tower (1), a primary distillation tower reflux device is connected to the top of the primary distillation tower (1), an atmospheric distillation tower reflux device is connected to the top of the atmospheric distillation tower (2), a feed device is provided at the front of the primary distillation tower (1), and a negative pressure tower is provided between the primary distillation tower (1) and the atmospheric distillation tower (2), characterized in that, The negative pressure tower includes a negative pressure tower one (16) connected to the primary distillation tower (1), a negative pressure tower one reflux device connected to the top of the negative pressure tower one (16), a negative pressure tower reboiler (22) provided in the middle and lower part of the negative pressure tower one (16), the negative pressure tower one (16) is connected to a negative pressure tower two (24) through a pipeline (23), a negative pressure tower one reboiler heating system (25) is provided on the pipeline (23), a negative pressure tower two reflux device is connected to the top of the negative pressure tower two (24), the pressure of the negative pressure tower one (16) is higher than the pressure of the negative pressure tower two (24), the bottom of the negative pressure tower two (24) is connected to the middle and lower part of the atmospheric pressure tower (2), and a negative pressure tower two reboiler heating system (95) is provided between the negative pressure tower two (24) and the atmospheric pressure tower (2). The atmospheric pressure tower (2) is connected to the atmospheric pressure stripping tower (66). One side of the atmospheric pressure stripping tower (66) is connected to the atmospheric pressure stripping tower extraction pipeline 1 (73), atmospheric pressure stripping tower extraction pipeline 2 (74), and atmospheric pressure stripping tower extraction pipeline 3 (75). One side of the pressure reducing tower (3) is connected to the pressure reducing stripping tower (83). One side of the pressure reducing stripping tower (83) is connected to the pressure reducing side line 2 (86), pressure reducing side line 3 (87), pressure reducing side line 4 (88), and pressure reducing side line 5 (89). The upper part of the pressure reducing side line 2 (86) is connected to the pressure reducing side line 1 (90) on the pressure reducing tower (3). The lower part of the pressure reducing side line 5 (89) is connected to the pressure reducing side line 6 (91) on the pressure reducing tower (3). The bottom of the pressure reducing tower (3) is connected to the pressure reducing residue oil extraction pipeline (92).

2. The five-tower atmospheric and vacuum distillation apparatus with energy-saving effect according to claim 1, characterized in that, At least one of the primary distillation tower reflux device, negative pressure tower one reflux device, and negative pressure tower two reflux device is connected to the naphtha separation device; the naphtha separation device includes a naphtha separation tower feed buffer tank (39), the naphtha separation tower feed buffer tank (39) is connected to the naphtha separation tower (41), the naphtha separation tower (41) is provided with a naphtha separation tower reflux device at the top, the naphtha separation tower reflux device is connected to the light naphtha production pipeline (44), and the naphtha separation tower (41) is provided with a heavy naphtha production pipeline (45) at the bottom.

3. The five-tower atmospheric and vacuum distillation apparatus with energy-saving effect according to claim 2, characterized in that, The feeding device includes a crude oil feed line one (50), which is connected to a desalting tank (52). A crude oil feed pump one (56) and a crude oil heating system (57) are installed on the crude oil feed line one (50). The desalting tank (52) is connected to a flash tank (54) through a crude oil feed line two (53). The flash tank (54) is connected to the primary distillation tower (1) through a crude oil feed line three (55). The top of the flash tank (54) is connected to a secondary flash tank (61). The bottom of the secondary flash tank (61) is connected to the naphtha separator feed buffer tank (39) through a secondary flash tank pipeline (62). A non-condensable gas pipeline (64) is connected to the top of the secondary flash tank (61).

4. The five-tower atmospheric and vacuum distillation apparatus with energy-saving effect according to claim 3, characterized in that, The crude oil heating system (57) is connected to the top of the primary distillation tower (1), the top of the atmospheric tower (2), the top of the negative pressure tower one (16), and the top of the negative pressure tower two (24), respectively. The gas phase at the top of the primary distillation tower (1), the gas phase at the top of the atmospheric tower (2), the gas phase at the top of the negative pressure tower one (16), and the gas phase at the top of the negative pressure tower two (24) exchange heat with the crude oil in the crude oil heating system (57) to provide heat for the crude oil heating system (57).

5. The five-tower atmospheric and vacuum distillation apparatus with energy-saving effect according to claim 4, characterized in that, The middle section of the primary distillation column (1) is equipped with a primary distillation column middle section circulating heating device (4).

6. The five-tower atmospheric and vacuum distillation apparatus with energy-saving effect according to claim 5, characterized in that, The atmospheric stripping tower outlet pipeline 1 (73) is connected to the bottom heating system (25) of the negative pressure tower 1. The bottom heating system (25) of the negative pressure tower 1 is connected to the circulating heating device (4) of the middle section of the primary distillation tower. The material extracted from the atmospheric stripping tower outlet pipeline 1 (73) undergoes primary heat exchange with the bottom heating system (25) of the negative pressure tower 1. After the primary heat exchange, it undergoes secondary heat exchange with the circulating heating device (4) of the middle section of the primary distillation tower. The atmospheric stripping tower outlet pipeline 2 (74) is connected to the bottom heating system (25) of the negative pressure tower 1. The bottom heating system (25) of the negative pressure tower 1 is connected to the naphtha fractionation tower feed heater (43). The material extracted from the atmospheric stripping tower outlet pipeline 2 (74) undergoes primary heat exchange with the bottom heating system (25) of the negative pressure tower 1. After the primary heat exchange, it undergoes secondary heat exchange with the naphtha fractionation tower feed heater (43). The atmospheric stripping tower outlet pipeline three (75) is connected to the bottom heating system (25) of the negative pressure tower one, the bottom heating system (25) of the negative pressure tower one is connected to the reboiler of the primary distillation tower (5), and the reboiler of the primary distillation tower (5) is connected to the circulating heating device (4) of the middle section of the primary distillation tower. The material extracted from the atmospheric stripping tower outlet pipeline three (75) undergoes a first-stage heat exchange with the bottom heating system (25) of the negative pressure tower one, a second-stage heat exchange with the reboiler of the primary distillation tower (5) after the first-stage heat exchange, and a third-stage heat exchange with the circulating heating device (4) of the middle section of the primary distillation tower after the second-stage heat exchange. The third-stage heat exchanger (87) is connected to the bottom heating system (25) of the first-stage heat exchanger of the negative pressure tower. The bottom heating system (25) of the first-stage heat exchanger is connected to the circulating heating device (4) of the middle section of the primary distillation tower. The material collected from the third-stage heat exchanger (87) undergoes a first-stage heat exchange with the bottom heating system (25) of the first-stage heat exchanger. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the circulating heating device (4) of the middle section of the primary distillation tower. After the second-stage heat exchange, the third-stage heat exchanger oil is collected through the third-stage heat exchanger (87). The fourth reducing line (88) is connected to the bottom heating system (25) of the first tower of the negative pressure tower. The bottom heating system (25) of the first tower of the negative pressure tower is connected to the reboiler of the primary distillation tower (5). The reboiler of the primary distillation tower (5) is connected to the circulating heating device (4) in the middle section of the primary distillation tower. The material collected from the fourth reducing line (88) undergoes a first-stage heat exchange with the bottom heating system (25) of the first tower of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiler of the primary distillation tower (5). After the second-stage heat exchange, it undergoes a third-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the third-stage heat exchange, the fourth reducing line oil is collected through the fourth reducing line (88). The fifth-stage heat exchanger (89) is connected to the heating system (95) of the second tower of the negative pressure tower. The heating system (95) of the second tower of the negative pressure tower is connected to the heating system (25) of the first tower of the negative pressure tower. The heating system (25) of the first tower of the negative pressure tower is connected to the circulating heating device (4) in the middle section of the primary distillation tower. The material collected from the fifth-stage heat exchanger (89) undergoes a first-stage heat exchange with the heating system (95) of the second tower of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the heating system (25) of the first tower of the negative pressure tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the third-stage heat exchange, the fifth-stage heat exchanger oil is collected through the fifth-stage heat exchanger (89). The reduced pressure side line (91) is sequentially connected to the heating system of the second tower of the negative pressure tower (95), the reboiler of the primary distillation tower (5), the heating system of the first tower of the negative pressure tower (25), and the circulating heating device of the middle section of the primary distillation tower (4). The material collected from the reduced pressure side line (91) undergoes a first-stage heat exchange with the heating system of the second tower of the negative pressure tower (95). After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiler of the primary distillation tower (5). After the second-stage heat exchange, it undergoes a third-stage heat exchange with the heating system of the first tower of the negative pressure tower (25). After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the circulating heating device of the middle section of the primary distillation tower (4). After the fourth-stage heat exchange, the reduced pressure oil is collected through the reduced pressure side line (91). The vacuum residue extraction pipeline (92) is sequentially connected to the vacuum tower reboiler heating system (95), the primary distillation tower reboiler (5), the vacuum tower reboiler heating system (25), the primary distillation tower mid-section circulating heating device (4), and the crude oil heating system (57). The material extracted from the vacuum residue extraction pipeline (92) undergoes a first-stage heat exchange with the vacuum tower reboiler heating system (95). After the first-stage heat exchange, it undergoes a second-stage heat exchange with the primary distillation tower reboiler (5). After the second-stage heat exchange, it undergoes a third-stage heat exchange with the vacuum tower reboiler heating system (25). After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the primary distillation tower mid-section circulating heating device (4). After the fourth-stage heat exchange, it enters the crude oil heating system (57) and undergoes a fifth-stage heat exchange with the crude oil in the crude oil heating system (57). After the fifth-stage heat exchange, the vacuum residue is extracted through the vacuum residue extraction pipeline (92).

7. A distillation method using a five-tower atmospheric and vacuum distillation apparatus with energy-saving effect as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Crude oil enters the desalting tank (52) through the crude oil heating system (57) for desalting and dehydration, and then is heated. The heated material enters the primary distillation tower (1). S2: The top reflux device at the top of the primary distillation column (1) extracts the top gas of the primary distillation column (1) and the light gasoline of the primary distillation column (1); S3: The bottom oil of the primary distillation tower (1) enters the negative pressure tower (16). The gas phase at the top of the negative pressure tower (16) is partially refluxed back to the negative pressure tower (16) after condensation, and part of it is separated into naphtha. S4: The material at the bottom of the first negative pressure tower (16) is heated and then enters the second negative pressure tower (24). The gas phase at the top of the second negative pressure tower (24) is condensed and then partially returned to the second negative pressure tower (24), and part of it is separated into naphtha. S5: The bottom oil of the negative pressure tower (24) is heated and then enters the atmospheric pressure tower (2). The gas phase at the top of the atmospheric pressure tower (2) is condensed and then refluxed back to the atmospheric pressure tower (2). The atmospheric pressure tower (2) is connected to the atmospheric pressure stripping tower (66). The atmospheric pressure stripping tower (66) has three outlet pipelines (73, 74, and 75) that produce finished oils with different compositions. S6: The bottom oil of the atmospheric pressure tower (2) is heated and then enters the pressure reducing tower (3). The steam injection device (80) at the top of the pressure reducing tower (3) extracts the gas at the top of the pressure reducing tower (3) and maintains the vacuum at the top of the tower. Condensed oil and water are collected from the top of the pressure reducing tower (3). S7: The bottom of the vacuum tower (3) extracts vacuum residue oil through the vacuum residue oil extraction pipeline (92). The vacuum tower (3) is connected to the vacuum stripping tower (83). The vacuum stripping tower (3) extracts the corresponding vacuum tower oil products from the vacuum stripping tower's side line (90) and side line (91), and the vacuum stripping tower (83) extracts the corresponding vacuum tower oil products from the side lines (86), side line (87), side line (88), and side line (89).

8. The five-tower atmospheric and vacuum distillation method with energy-saving effect according to claim 7, characterized in that, The gas phase at the top of the primary distillation tower (1), the gas phase at the top of the atmospheric tower (2), the gas phase at the top of the negative pressure tower one (16), the gas phase at the top of the negative pressure tower two (24), and the liquid phase collected from the circulating heat extraction (94) in the middle section of the negative pressure tower two respectively enter the crude oil heating system (57) to exchange heat with the crude oil in the crude oil heating system (57) and provide heat for the crude oil heating system (57).

9. The five-tower atmospheric and vacuum distillation method with energy-saving effect according to claim 7, characterized in that, The material extracted from the atmospheric stripping tower outlet pipeline (73) undergoes a first-stage heat exchange with the bottom heating system (25) of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the second-stage heat exchange, kerosene is extracted through the atmospheric stripping tower outlet pipeline (73). The material extracted from the atmospheric stripping tower outlet pipeline 2 (74) undergoes a first-stage heat exchange with the bottom heating system (25) of the negative pressure tower 1. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the naphtha fractionation tower feedstock heater (43). After the second-stage heat exchange, light diesel oil is extracted through the atmospheric stripping tower outlet pipeline 2 (74). The material extracted from the atmospheric stripping tower outlet pipeline three (75) undergoes a first-stage heat exchange with the bottom heating system (25) of the negative pressure tower one. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiling device (5) of the primary distillation tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the third-stage heat exchange, heavy diesel oil is extracted through the atmospheric stripping tower outlet pipeline three (75). The material extracted from the vacuum residue production pipeline (92) undergoes a first-stage heat exchange with the heating system (95) of the second tower of the vacuum tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiling device (5) of the primary distillation tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the heating system (25) of the first tower of the vacuum tower. After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the fourth-stage heat exchange, it undergoes a fifth-stage heat exchange with the crude oil heating system (57). After the fifth-stage heat exchange, the vacuum residue is extracted through the vacuum residue production pipeline (92). The material collected from the third side line (87) undergoes a first-stage heat exchange with the heating system (25) of the bottom of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the second-stage heat exchange, the third-stage oil is collected through the third side line (87). The material collected from the fourth side line (88) undergoes a first-stage heat exchange with the heating system (25) of the bottom of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiling device (5) of the primary distillation tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the third-stage heat exchange, the fourth-stage oil is collected through the fourth side line (88). The material collected from the fifth reducing side stream (89) undergoes a first-stage heat exchange with the heating system (95) of the second tower of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the heating system (25) of the first tower of the negative pressure tower to provide heat for the heating system (25) of the first tower of the negative pressure tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the third-stage heat exchange, the fifth reducing oil is collected through the fifth reducing side stream (89). The material collected from the reduced pressure tower side line (91) undergoes a first-stage heat exchange with the heating system (95) of the second tower of the negative pressure tower. After the first-stage heat exchange, it undergoes a second-stage heat exchange with the reboiling device (5) of the primary distillation tower. After the second-stage heat exchange, it undergoes a third-stage heat exchange with the heating system (25) of the first tower of the negative pressure tower. After the third-stage heat exchange, it undergoes a fourth-stage heat exchange with the circulating heating device (4) in the middle section of the primary distillation tower. After the fourth-stage heat exchange, the reduced pressure tower oil is collected through the reduced pressure tower side line (91).

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