A method for recovering waste heat from a pressurized column

Abstract

The application discloses a kind of waste heat recovery and utilization methods of pressurized tower, belong to energy-saving and environmental protection technical field.The method includes: (1) with recovery tower overhead gas phase as heat source into pressurized tower reboiler and carries out heat exchange treatment;(2) with pressurized tower overhead gas phase as heat source into atmospheric tower reboiler and carries out heat exchange treatment.The application discloses a kind of waste heat recovery and utilization methods of pressurized tower, by the waste heat of recovery tower overhead gas phase, replace part 1.0MPa steam heating, reduce energy consumption, improve heat efficiency;The method is convenient and fast to the modification of existing pressurized tower, easy to implement, with wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of energy conservation and environmental protection, and in particular to a method for recovering and utilizing waste heat from a pressurization tower. Background Technology

[0002] A pressurization tower is a type of chemical equipment primarily used in industrial production for mass and heat transfer between gas and liquid or liquid and liquid phases. It achieves separation and purification of substances by ensuring sufficient contact between different phases through its internal components. Pressurization towers are widely used in the chemical, petroleum, biological, and pharmaceutical industries.

[0003] The pressurized column has a bottom temperature of 138℃ and a pressure of 0.81 MPa, and a top temperature of 136.2℃ and a top pressure of 0.80 MPa. The top and bottom of the pressurized column are connected to a pressurized column reboiler and an atmospheric column reboiler, respectively. The pressurized column reboiler receives 1.0 MPa steam to heat the liquid in the bottom. The steam condenses into condensate and enters a pre-reboiler, where it undergoes further heat exchange. The condensate is then returned to the condensate network. The vapor phase from the top of the pressurized column enters the atmospheric column reboiler, where it exchanges heat with the liquid in the atmospheric column. After heat exchange, the vapor phase is cooled into a liquid phase by a circulating water cooler. The cooled liquid phase then enters a reflux tank and returns to the pressurized column, completing the cycle.

[0004] Currently, the heat source for the pressurized tower bottom is only 1.0 MPa steam, resulting in high energy consumption. To further reduce energy consumption and improve thermal efficiency, the pressurized tower can be further modified. Summary of the Invention

[0005] The purpose of this invention is to provide a method for recovering and utilizing waste heat from a pressurized tower. By recovering the waste heat from the gas phase at the top of the tower, a portion of the 1.0 MPa steam heating can be replaced, thereby reducing energy consumption and improving heat utilization efficiency.

[0006] To achieve the above objectives, the present invention provides a method for waste heat recovery and utilization from a pressurization tower, comprising:

[0007] (1) The gas phase at the top of the recovery tower is used as a heat source to enter the reboiler of the pressurized tower for heat exchange treatment;

[0008] (2) The gas phase at the top of the pressurized tower is used as a heat source to enter the reboiler of the atmospheric tower for heat exchange treatment.

[0009] Preferably, the pressurized tower reboiler is configured with two units, each of which is connected to a return gas inlet pipe of a pressurized tower reboiler. The return gas inlets of the pressurized tower reboilers are symmetrically arranged on one side of the pressurized tower bottom collection tank.

[0010] Preferably, the condensate from the top gas phase of the recovery tower is obtained after heat exchange in the reboiler of the pressurized tower. The condensate is sent to the cooler to exchange heat with the bottom liquid from the bottom collection tank of the pressurized tower. After heat exchange, the condensate enters the reflux tank of the recovery tower, and the bottom liquid returns to the reboiler of the pressurized tower and then to the bottom of the pressurized tower.

[0011] Preferably, a nitrogen inlet for the reboiler of the pressurized tower is provided on the side of the return gas inlet.

[0012] Preferably, a gas outlet baffle is welded at the gas outlet at the top of the pressurized tower. The gas flow rate is controlled by the gas outlet baffle, and the gas is made to form a vortex in the pipeline, thereby improving the heat exchange efficiency of the gas phase at the top of the pressurized tower after entering the reboiler of the atmospheric tower.

[0013] The gas outlet baffle includes a spliced ​​circular base with several through holes evenly distributed on it. The base is welded to the top of the pressurization tower by angle steel. The angle steel is set at an angle of 3 to 5 degrees with the vertical direction.

[0014] Preferably, the column bottom liquid collection tank includes a first liquid collection tank and a second liquid collection tank for collecting column bottom liquid, liquid outlet pipes are symmetrically arranged on both sides of the second liquid collection tank, and supporting ribs are provided below the liquid outlet pipes.

[0015] Therefore, the waste heat recovery and utilization method of the pressurization tower of the present invention has the following beneficial effects:

[0016] (1) Weld a gas outlet baffle at the gas outlet at the top of the recovery tower. By adjusting the angle of the baffle, the gas can form a vortex in the pipe, thereby optimizing the gas flow and improving the heat exchange efficiency.

[0017] (2) The return gas inlet of the pressurized tower reboiler is located below the bottom liquid collection tank of the tower and is connected to the pressurized tower reboiler. An additional return gas inlet is added on its symmetrical side to improve the utilization rate of the gas phase.

[0018] (3) The top gas phase of the recovery tower is used as a heat source to enter the reboiler of the pressurized tower for heat exchange. The amount of 1.0MPa steam used before and after the modification was reduced by 20t / h.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1This is a schematic diagram of the top structure of the pressurization tower;

[0022] Figure 2 This is a top view of the gas outlet baffle.

[0023] Figure 3 This is a schematic diagram of the liquid collection tank in the column bottom and its surrounding structure.

[0024] Figure label:

[0025] 1. Gas outlet baffle; 101. Chassis; 102. Angle steel; 2. Tower bottom liquid collection tank; 201. First liquid collection tank; 202. Second liquid collection tank; 203. Liquid outlet pipe; 204. Support rib; 3. Pressurized tower reboiler return gas inlet; 4. Tower bottom nitrogen inlet. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of this application clearer, more thorough, and more complete, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The following detailed descriptions are all illustrations of embodiments, intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] Example 1

[0029] A method for waste heat recovery and utilization from a pressurization tower, comprising:

[0030] (1) The gas phase at the top of the pressurized tower is used as a heat source to enter the reboiler of the atmospheric tower for heat exchange treatment. A gas outlet baffle 1 is welded at the gas outlet at the top of the pressurized tower, such as... Figure 1 As shown; a top view of the gas outlet baffle 1 is shown below. Figure 2 As shown.

[0031] The gas outlet baffle 1 includes a spliced ​​circular base 101 with several through holes evenly distributed on it (not shown in the figure). The base 101 is welded to the top of the pressurization tower via angle steel 102. The angle steel 102 is welded at an angle of 3-5° to the vertical direction.

[0032] The gas outlet baffle 1 controls the gas flow rate, ensuring it remains within a suitable range to meet production needs while guaranteeing the safe and stable operation of the pipeline and its surrounding environment. Simultaneously, adjusting the angle of the angle steel 102 during welding creates vortices in the gas flow within the pipeline, optimizing gas flow and improving the heat exchange efficiency of subsequent processes.

[0033] (2) The top gas phase of the recovery tower is used as a heat source to replace the original 1.0 MPa steam entering the reboiler of the pressurized tower for heat exchange treatment.

[0034] like Figure 3 The image shows the liquid collection tank at the bottom of the tower and its surrounding structure.

[0035] The column bottom liquid collection tank 2 includes a first liquid collection tank 201 and a second liquid collection tank 202 for collecting the liquid from the column bottom. The second liquid collection tank 202 is formed by welding after removing the original liquid seal plate below the first liquid collection tank 201. Liquid outlet pipes 203 are symmetrically arranged on both sides of the second liquid collection tank 202, and support ribs 204 are provided below the liquid outlet pipes 203.

[0036] The return gas inlet 3 of the pressurized tower reboiler is located below the bottom collection tank 2 and is connected to the pressurized tower reboiler. The location of the return gas inlet 3 is the original location of the pressurized tower, except that another return gas inlet 3 is added symmetrically on its side. Each of the two return gas inlets 3 is connected to one pressurized tower reboiler. The pressurized tower reboiler is existing technology. Figure 3 Not shown in the image.

[0037] The overhead vapor phase (161°C) from the recovery tower enters the reboilers of two pressurized towers for heat exchange. After heat exchange, the resulting condensate from the recovery tower is sent to the same cooler, where it exchanges heat with the bottom liquid (101.3°C) from the bottom collection tank 2 of the pressurized tower. After heat exchange, the condensate from the recovery tower (118°C) enters the reflux tank of the recovery tower, and the bottom liquid returns to the reboiler of the pressurized tower and then back to the bottom of the pressurized tower. Simultaneously, the cooler cools the unliquefied overhead vapor phase carried by the condensate from the recovery tower.

[0038] A nitrogen inlet 4 is provided on one side of the reboiler return gas inlet 3 of the pressurized tower. The nitrogen serves as a replacement and protection function. The position of the nitrogen inlet 4 in the tower bottom only needs to meet the material inlet and outlet requirements, and can be set according to actual needs.

[0039] The original process of the pressurization tower used 75t / h of 1.0MPa steam. After the modification, the top gas phase of the recovery tower was used as the heat source of the pressurization tower bottom, which completely replaced the 1.0MPa steam. The 1.0MPa steam was directly used as the heat source of the recovery tower, with a consumption of 55t / h. The consumption of 1.0MPa steam was reduced by 20t / h before and after the modification.

[0040] Therefore, the present invention provides a waste heat recovery and utilization method for a pressurization tower, which reduces energy consumption and improves thermal efficiency by recovering the waste heat of the gas phase at the top of the tower to replace part of the 1.0MPa steam heating. This method is convenient, quick and easy to implement for the modification of existing pressurization towers and has broad application prospects.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for waste heat recovery and utilization from a pressurization tower, characterized in that, include: (1) The gas phase at the top of the recovery tower is used as a heat source to enter the reboiler of the pressurized tower for heat exchange treatment; (2) The gas phase at the top of the pressurized tower is used as a heat source to enter the reboiler of the atmospheric tower for heat exchange treatment; A gas outlet baffle is welded at the gas outlet at the top of the pressurized tower. The gas flow rate is controlled by the gas outlet baffle and the gas is made to form a vortex in the pipeline, thereby improving the heat exchange efficiency of the gas phase at the top of the pressurized tower after entering the reboiler of the atmospheric tower. The gas outlet baffle includes a spliced ​​circular base with several through holes evenly distributed on it. The base is welded to the top of the pressurization tower by angle steel. The angle steel is set at an angle of 3 to 5 degrees with the vertical direction.

2. The method for waste heat recovery and utilization from a pressurization tower according to claim 1, characterized in that: Two reboilers are configured for the pressurized tower. Each of the two pressurized tower reboilers is connected to a return gas inlet pipe of one pressurized tower reboiler. The return gas inlets of the pressurized tower reboilers are symmetrically located on one side of the liquid collection tank at the bottom of the pressurized tower.

3. The method for waste heat recovery and utilization from a pressurization tower according to claim 2, characterized in that: After the vapor phase at the top of the recovery tower undergoes heat exchange in the reboiler of the pressurized tower, the condensate from the recovery tower is obtained. The condensate from the recovery tower is sent to the cooler to exchange heat with the liquid from the bottom collection tank of the pressurized tower. After heat exchange, the condensate from the recovery tower enters the reflux tank of the recovery tower, and the liquid from the bottom of the tower returns to the reboiler of the pressurized tower and then returns to the bottom of the pressurized tower.

4. The method for waste heat recovery and utilization from a pressurization tower according to claim 2, characterized in that: A nitrogen inlet for the reboiler of the pressurized tower is provided on the side of the return gas inlet.

5. The method for waste heat recovery and utilization from a pressurization tower according to claim 2, characterized in that: The column bottom liquid collection tank includes a first liquid collection tank and a second liquid collection tank for collecting the column bottom liquid. Liquid outlet pipes are symmetrically arranged on both sides of the second liquid collection tank, and support ribs are provided below the liquid outlet pipes.

Images