Energy recovery system for absorption tower of light hydrocarbon recovery device

Abstract

The utility model relates to the technical field of light hydrocarbon recovery processes, in particular to an absorption tower energy recovery system of a light hydrocarbon recovery device. A feeding pipeline of the absorption tower is connected with the first circulating water cooler, and waste heat exchangers are sequentially arranged on the feeding pipeline of the absorption tower; the absorption tower is connected with an absorption tower feeding pipeline; the tower bottom of the absorption tower is connected with a tower bottom pump; the rich absorption liquid pipeline is connected with a tower bottom pump; the naphtha buffer tank is connected with a rich absorption liquid pipeline; a feeding pipeline of the stabilizing tower is connected with the naphtha buffer tank; the stabilizing tower is connected with a stabilizing tower feeding pipeline; a discharging pipeline at the bottom of the stabilizing tower is contacted with a feeding pipeline of the absorption tower at the upstream of the waste heat exchanger; and the waste heat exchanger is connected to the rich absorption liquid pipeline and is connected to the stabilizing tower feeding pipeline. According to the utility model, the temperature of mixed materials is reduced, the use amount of heating steam of the stabilizing tower can be reduced to a certain extent, the utilization rate of energy is improved, and the energy is further saved.

Description

Technical Field

[0001] The utility model relates to the technical field of light hydrocarbon recovery process, in particular to an energy recovery system of an absorption tower of a light hydrocarbon recovery device. Background Art

[0002] In the original light hydrocarbon recovery process, the first-stage naphtha of the atmospheric vacuum unit with a temperature of about 95°C is mixed with the bottom naphtha of the stabilizer tower with a temperature of about 82°C, and then cooled to 40°C by an air cooler, and then cooled to 10°C by refrigerant water before entering the absorption tower. However, in this process, after the first-stage atmospheric vacuum unit oil and the bottom naphtha of the stabilizer tower are mixed, the temperature of the mixed material is 86°C, and it is directly cooled to 40°C by air cooling, and its heat is not fully recovered and utilized, resulting in energy waste. Utility Model Content

[0003] In view of the defects of the prior art, the utility model provides an energy recovery system for an absorption tower of a light hydrocarbon recovery device, which utilizes a waste heat exchanger to replace an air cooler, thereby solving the problem of low heat utilization rate of atmospheric and vacuum first-stage oil and stable tower bottom naphtha to a certain extent.

[0004] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is an energy recovery system for an absorption tower of a light hydrocarbon recovery device, which includes a normal and low-pressure first-level naphtha pipeline, a first circulating water cooler, an absorption tower feed pipeline, an absorption tower, a rich absorption liquid pipeline, a naphtha buffer tank, a stabilization tower feed pipeline, a stabilization tower, and a stabilization tower bottom discharge pipeline; the first circulating water cooler is connected to the normal and low-pressure first-level naphtha pipeline; the absorption tower feed pipeline is connected to the first circulating water cooler, and a waste heat exchanger, a second circulating water cooler, and a refrigerant water cooler are sequentially arranged on the absorption tower feed pipeline; the absorption tower and the The absorber is connected to the absorber feed pipeline, and the bottom of the absorber is connected to a bottom pump; the rich absorption liquid pipeline is connected to the bottom pump; the naphtha buffer tank is connected to the rich absorption liquid pipeline; the stabilization tower feed pipeline is connected to the naphtha buffer tank; the stabilization tower is connected to the stabilization tower feed pipeline; the stabilization tower bottom discharge pipeline is connected to the bottom of the stabilization tower, and the stabilization tower bottom discharge pipeline meets the absorber feed pipeline upstream of the waste heat exchanger; the waste heat exchanger includes a first inlet and a first outlet, the first inlet is connected to the rich absorption liquid pipeline, and the first outlet is connected to the stabilization tower feed pipeline.

[0005] Furthermore, the absorber feed pipeline is provided with a lean absorption oil air cooler, and the waste heat exchanger includes a second inlet and a second outlet, the second inlet is connected to the absorber feed pipeline between the stabilization tower bottom discharge pipe and the lean absorption oil air cooler, and the second outlet is connected to the absorber feed pipeline between the lean absorption oil air cooler and the second circulating water cooler.

[0006] Furthermore, a first valve and a second valve are provided on the absorption tower feed pipeline, and the first valve and the second valve are respectively arranged upstream and downstream of the lean absorption oil air cooler to isolate the lean absorption oil air cooler.

[0007] Furthermore, a third valve and a fourth valve are respectively arranged near the second inlet and the second outlet to isolate the waste heat exchanger.

[0008] Furthermore, the first inlet of the waste heat exchanger is connected to the downstream of the tower bottom pump through a pipeline.

[0009] Furthermore, a feed pump and a feed heat exchanger are sequentially arranged on the feed pipeline of the stabilization tower.

[0010] Furthermore, the first outlet of the waste heat exchanger is connected to a stabilizing tower feed pipeline between the feed pump and the feed heat exchanger through a pipeline.

[0011] Furthermore, the bottom discharge pipe of the stabilization tower is connected to the low-temperature hot water heat exchanger through the feed heat exchanger.

[0012] Furthermore, a bottom reboiler is connected to the bottom of the stabilization tower.

[0013] The beneficial effects of the utility model are as follows: the temperature of the first-stage atmospheric and vacuum naphtha pipeline is 95°C, the temperature of the naphtha at the bottom of the stabilizing tower in the discharge pipeline at the bottom of the stabilizing tower is 82°C, the mixed temperature of the two streams of materials is 86°C, and then it is cooled to 40°C by air cooling through the waste heat exchanger, and then cooled to 10°C through the second circulating water cooler and the refrigerant water cooler, and then enters the absorption tower; the temperature of the absorber-rich absorption oil at the bottom of the absorption tower is 38°C, and after heat exchange through the waste heat exchanger, it is increased to 74°C, and enters the stabilizing tower for product separation, and the heating steam consumption of the stabilizing tower is reduced by 5t / h. The utility model further utilizes the heat of the mixed material with an oil temperature of 86°C to heat exchange and heat the material entering the stabilizing tower by adding a waste heat exchanger, which not only reduces the temperature of the mixed material, but also reduces the heating steam consumption of the stabilizing tower to a certain extent, improves the energy utilization rate, and thus saves energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a process flow chart of an energy recovery system of an absorption tower of a light hydrocarbon recovery device in one embodiment of the utility model;

[0015] Figure 2 It is a process flow chart of an energy recovery system of an absorption tower of a light hydrocarbon recovery device in another embodiment of the utility model;

[0016] In the figure:

[0017] 100. Atmospheric and vacuum first-level naphtha pipeline,

[0018] 200. The first circulating water cooler,

[0019] 300, absorption tower feed pipeline, 310, waste heat exchanger, 311, first inlet, 312, first outlet, 313, second inlet, 314, second outlet, 315, third valve, 316, fourth valve, 320, second circulating water cooler, 330, refrigerant water cooler, 340, lean absorption oil air cooler, 350, first valve, 360, second valve,

[0020] 400, absorption tower, 410, bottom pump,

[0021] 500, Rich absorption liquid pipeline,

[0022] 600, naphtha buffer tank,

[0023] 700, stabilization tower feed pipeline, 710, feed pump, 720, feed heat exchanger,

[0024] 800, stabilization tower, 810, bottom reboiler,

[0025] 900. Discharge pipe at the bottom of the stabilizing tower. 910. Low-temperature hot water heat exchanger. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0027] See attached Figure 1, shows an energy recovery system for an absorption tower of a light hydrocarbon recovery device in one embodiment of the utility model, which includes a normal and low pressure primary naphtha pipeline 100, a first circulating water cooler 200, an absorption tower feed pipeline 300, an absorption tower 400, a rich absorption liquid pipeline 500, a naphtha buffer tank 600, a stabilization tower feed pipeline 700, a stabilization tower 800 and a stabilization tower bottom discharge pipeline 900. The first circulating water cooler 200 is connected to the atmospheric and vacuum primary naphtha pipeline 100; the absorption tower feed pipeline 300 is connected to the first circulating water cooler 200, and the absorption tower feed pipeline 300 is sequentially provided with a waste heat exchanger 310, a second circulating water cooler 320 and a refrigerant water cooler 330; the absorption tower 400 is connected to the absorption tower feed pipeline 300, and the bottom of the absorption tower 400 is connected to a bottom pump 410; the rich absorption liquid pipeline 500 is connected to the bottom pump 410; the naphtha buffer tank 600 is connected to the rich absorption liquid pipeline 500 is connected; a stabilization tower feed pipeline 700 is connected to a naphtha buffer tank 600; a stabilization tower 800 is connected to a stabilization tower feed pipeline 700; a stabilization tower bottom discharge pipeline 900 is connected to the bottom of the stabilization tower 800, and the stabilization tower bottom discharge pipeline 900 meets the absorption tower feed pipeline 300 upstream of the waste heat exchanger 310; the waste heat exchanger 310 includes a first inlet 311 and a first outlet 312, the first inlet 311 is connected to the rich absorption liquid pipeline, and the first outlet 312 is connected to the stabilization tower feed pipeline 700.

[0028] The temperature of the normal vacuum first-stage naphtha pipeline 100 of the energy recovery system of the light hydrocarbon recovery device absorption tower is 95°C, the temperature of the stabilized tower bottom naphtha in the stabilizer bottom discharge pipeline 900 is 82°C, and the mixed temperature of the two streams of materials is 86°C. It is then air-cooled to 40°C through the waste heat exchanger 310, and then cooled to 10°C through the second circulating water cooler 320 and the refrigerant water cooler 330, and enters the absorption tower; the temperature of the absorber rich absorption oil at the bottom of the absorption tower 400 is 38°C, and after heat exchange in the waste heat exchanger 310, it is increased to 74°C and enters the stabilizer 800 for product separation. The heating steam consumption of the stabilizer 800 is reduced by 5t / h. The above-mentioned light hydrocarbon recovery device absorption tower energy recovery system adds a waste heat exchanger 310 to further utilize the heat of the mixed material with an oil temperature of 86°C, specifically the heat of the stabilized tower bottom naphtha at 82°C and the normal vacuum first-grade oil at 95°C, to heat exchange and heat up the materials entering the stabilizer tower 800, which not only reduces the temperature of the mixed material, but also reduces the heating steam consumption of the stabilizer tower 800 to a certain extent, thereby improving the energy utilization rate and saving energy.

[0029] In order to save costs, the original pipeline of the lean absorption oil air cooler 340 can be directly modified, see Figure 2In one embodiment, the absorption tower feed pipeline 300 is provided with a lean absorption oil air cooler 340, and the waste heat exchanger 310 includes a second inlet 313 and a second outlet 314. The second inlet 313 is connected to the absorption tower feed pipeline 300 between the stabilization tower bottom discharge pipeline 900 and the lean absorption oil air cooler 340, and the second outlet 314 is connected to the absorption tower feed pipeline 300 between the lean absorption oil air cooler 340 and the second circulating water cooler 320. In this way, the waste heat exchanger 310 is directly arranged in a parallel connection manner to the bypass of the lean absorption oil air cooler 340 by using the newly added pipeline, so as to facilitate switching between the original process and the new process, thereby improving the flexibility of the system and facilitating offline maintenance of the waste heat exchanger 310.

[0030] To further facilitate switching between the original process and the new process, continue to refer to Figure 2 In one embodiment, a first valve 350 and a second valve 360 ​​are provided on the absorption tower feed pipeline 300, and the first valve 350 and the second valve 360 ​​are respectively provided upstream and downstream of the lean absorption oil air cooler 340 to isolate the lean absorption oil air cooler 340. On the basis of the above embodiment, a third valve 315 and a fourth valve 316 are respectively provided near the second inlet 313 and the second outlet 314 to isolate the waste heat exchanger 310.

[0031] In one embodiment, the first inlet 311 of the waste heat exchanger 310 is connected to the downstream of the tower bottom pump 410 through a pipeline.

[0032] In one embodiment, a feed pump 710 and a feed heat exchanger 720 are sequentially disposed on the stabilization tower feed pipeline 700 .

[0033] In one embodiment, the first outlet 312 of the waste heat exchanger 310 is connected to a stabilizer tower feed line 700 between a feed pump 710 and a feed heat exchanger 720 through a pipeline.

[0034] In one embodiment, the stabilization tower bottom discharge pipeline 900 is connected to the low-temperature hot water heat exchanger 910 via the feed heat exchanger 720 .

[0035] It should be noted that the flow rate of the atmospheric and vacuum primary naphtha pipeline 100 is adjusted between 0t / h and 90t / h; the temperature is 40°C-95°C, and the temperature is 40°C-50°C after heat exchange with the rich absorption liquid at the bottom of the absorption tower 400 through the waste heat exchanger 310, and the temperature of the rich absorption liquid is 40°C-75°C. The rich absorption liquid enters the stabilization tower, and the feed temperature of the stabilization tower 800 is 40°C-60°C, and the temperature is 106°C-110°C after heat exchange with the material at the bottom of the stabilization tower through the feed heat exchanger 720.

[0036] In one embodiment, a bottom reboiler 810 is connected to the bottom of the stabilization tower 800 .

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present utility model, unless otherwise clearly specified and limited, the first feature "above" or "below" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

Claims

1. An energy recovery system for an absorption tower of a light hydrocarbon recovery device, characterized in that: include Atmospheric and vacuum primary naphtha pipeline; A first circulating water cooler connected to the atmospheric and vacuum primary naphtha pipeline; An absorption tower feed pipeline is connected to the first circulating water cooler, and a waste heat exchanger, a second circulating water cooler and a refrigerant water cooler are sequentially arranged on the absorption tower feed pipeline; An absorption tower, connected to the absorption tower feed pipeline, and a bottom pump is connected to the bottom of the absorption tower; A rich absorption liquid pipeline connected to the tower bottom pump; a naphtha buffer tank connected to the rich absorption liquid pipeline; A stabilization tower feed pipeline connected to the naphtha buffer tank; a stabilization tower connected to the stabilization tower feed pipeline; A stabilization tower bottom discharge pipeline is connected to the bottom of the stabilization tower, and the stabilization tower bottom discharge pipeline meets the absorption tower feed pipeline upstream of the waste heat exchanger; The waste heat exchanger comprises a first inlet and a first outlet, wherein the first inlet is connected to the rich absorption liquid pipeline, and the first outlet is connected to the stabilization tower feed pipeline.

2. The light hydrocarbon recovery device absorption tower energy recovery system according to claim 1, characterized in that: The absorber feed pipeline is provided with a lean absorption oil air cooler, and the waste heat exchanger includes a second inlet and a second outlet, the second inlet is connected to the absorber feed pipeline between the stabilization tower bottom discharge pipeline and the lean absorption oil air cooler, and the second outlet is connected to the absorber feed pipeline between the lean absorption oil air cooler and the second circulating water cooler.

3. The light hydrocarbon recovery device absorption tower energy recovery system according to claim 2, characterized in that: The absorption tower feed pipeline is provided with a first valve and a second valve, and the first valve and the second valve are respectively arranged upstream and downstream of the lean absorption oil air cooler to isolate the lean absorption oil air cooler.

4. The light hydrocarbon recovery device absorption tower energy recovery system according to claim 2, characterized in that: A third valve and a fourth valve are respectively arranged near the second inlet and the second outlet to isolate the waste heat exchanger.

5. A light hydrocarbon recovery device absorption tower energy recovery system according to any one of claims 1 to 3, characterized in that: The first inlet of the waste heat exchanger is connected to the downstream of the tower bottom pump through a pipeline.

6. A light hydrocarbon recovery device absorption tower energy recovery system according to any one of claims 1 to 3, characterized in that: A feed pump and a feed heat exchanger are sequentially arranged on the feed pipeline of the stabilization tower.

7. The light hydrocarbon recovery device absorption tower energy recovery system according to claim 6, characterized in that: The first outlet of the waste heat exchanger is connected to a stabilizing tower feed pipeline between the feed pump and the feed heat exchanger through a pipeline.

8. The light hydrocarbon recovery device absorption tower energy recovery system according to claim 6, characterized in that: The bottom discharge pipeline of the stabilization tower is connected to the low-temperature hot water heat exchanger through the feed heat exchanger.

9. An energy recovery system for an absorption tower of a light hydrocarbon recovery device according to any one of claims 1 to 3, characterized in that: The bottom of the stabilization tower is connected with a bottom reboiler.

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