CN111233793A - System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device - Google Patents
System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device Download PDFInfo
- Publication number
- CN111233793A CN111233793A CN202010175413.9A CN202010175413A CN111233793A CN 111233793 A CN111233793 A CN 111233793A CN 202010175413 A CN202010175413 A CN 202010175413A CN 111233793 A CN111233793 A CN 111233793A
- Authority
- CN
- China
- Prior art keywords
- lean
- ethylene oxide
- liquid
- rich
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 118
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 title claims abstract description 112
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 107
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000003795 desorption Methods 0.000 claims abstract description 41
- 238000011084 recovery Methods 0.000 claims abstract description 39
- 239000002918 waste heat Substances 0.000 claims abstract description 39
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 37
- 239000000498 cooling water Substances 0.000 claims abstract description 10
- 238000010992 reflux Methods 0.000 claims description 18
- 238000005086 pumping Methods 0.000 claims description 14
- 238000004891 communication Methods 0.000 claims description 6
- 239000006096 absorbing agent Substances 0.000 claims description 5
- 239000007789 gas Substances 0.000 claims description 3
- 238000005057 refrigeration Methods 0.000 description 16
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 150000002924 oxiranes Chemical class 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D301/00—Preparation of oxiranes
- C07D301/32—Separation; Purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
- C07D303/02—Compounds containing oxirane rings
- C07D303/04—Compounds containing oxirane rings containing only hydrogen and carbon atoms in addition to the ring oxygen atoms
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B27/00—Machines, plants or systems, using particular sources of energy
- F25B27/02—Machines, plants or systems, using particular sources of energy using waste heat, e.g. from internal-combustion engines
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D21/0001—Recuperative heat exchangers
- F28D21/0012—Recuperative heat exchangers the heat being recuperated from waste water or from condensates
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/27—Relating to heating, ventilation or air conditioning [HVAC] technologies
- Y02A30/274—Relating to heating, ventilation or air conditioning [HVAC] technologies using waste energy, e.g. from internal combustion engine
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
Abstract
The invention discloses a system and a method for reducing the temperature of ethylene oxide absorption liquid in an EO/EG device, and the EO/EG device, wherein a waste heat recovery device is arranged at the downstream of a lean/rich liquid heat exchanger and used for recovering the heat of lean liquid flowing out of the lean/rich liquid heat exchanger so as to reduce the temperature of the lean liquid to the temperature required by an ethylene oxide absorption tower; after flowing out of the ethylene oxide desorption tower, the barren solution exchanges heat with the rich solution in the barren/rich solution heat exchanger, so that the temperature of the barren solution subjected to heat exchange is higher and is usually about 118 ℃, so that the barren solution is more in heat quantity transmitted to the rich solution, the rich solution is raised to a higher temperature, the temperature of the rich solution entering the ethylene oxide desorption tower is raised, and the heat quantity of a high-grade heat source of a reboiler of the desorption tower, which is correspondingly consumed, is greatly reduced; and the heat quantity of the lean solution conveyed to the rich solution in the lean/rich solution heat exchanger is large, and the heat quantity which needs to be taken away by cooling water in a subsequent waste heat recovery device is correspondingly small, so that the water consumption and the power consumption of the cooling water are saved.
Description
Technical Field
The invention relates to the technical field of ethylene oxide preparation, in particular to a system and a method for reducing the temperature of ethylene oxide absorption liquid in an EO/EG device and the EO/EG device.
Background
Ethylene oxide (EO for short) is the simplest cyclic ether, is an important organic chemical product in ethylene industrial derivatives, which is second to polyethylene and polyvinyl chloride, and is the simplest and most important epoxide. Ethylene glycol (EG for short in English) is the simplest dihydric alcohol and is a very important organic chemical product in ethylene industrial derivatives, 95 percent of ethylene glycol is consumed on polyester, and both EO and EG have great significance and function in national economic development.
Referring to FIG. 1, FIG. 1 is a schematic diagram of a prior art EO/EG device.
The EO/EG device in the prior art comprises an ethylene oxide absorption tower 1, a desorption tower 2, a desorption tower top cooler 3, a desorption tower reflux tank 4, a reflux pump 5, a desorption tower reboiler 6, an absorption refrigerator 7, a lean/rich liquid heat exchanger 8 and a circulating water cooler 9. The lean solution (the lean solution temperature is about 118 ℃) at the bottom of the desorption tower 2 is used as a heat source to drive the hot water type absorption refrigerator 7, the temperature is reduced (the temperature is about 90 ℃) after the lean solution is taken out of the refrigerator, then the lean solution and the rich solution enter the lean/rich solution heat exchanger 8, the temperature of the lean/rich solution is further reduced (the temperature is reduced to about 60 ℃) at the same time, the temperature of the rich solution is increased (the temperature of the rich solution is increased from 55 ℃ to about 85 ℃ usually), the rich solution enters the desorption tower and releases ethylene oxide after being heated, the heated heat source is from a reboiler 6 of the desorption tower, the reboiler 6 of the desorption tower consumes high-level heat sources such as steam, heat transfer oil and the.
In addition, the concentration of ethylene oxide at the top of an ethylene oxide absorption tower 1 in an EO/EG device is required to be controlled below 70 ppmol, while the temperature of the absorption liquid of the prior art device is high, once the temperature of the absorption liquid is higher than 33 ℃, the concentration at the top of the absorption tower is higher than 100 ppmol, and particularly in summer, the prior art device cannot reduce the temperature at the top of the absorption liquid to below 35 ℃, so that the capacity of the device is seriously influenced.
The goal of those skilled in the art is to reduce the water consumption of EO/EG plants and to reduce the cost of the plant.
Disclosure of Invention
The invention provides a system for reducing the temperature of ethylene oxide absorption liquid in an EO/EG device, which comprises the following components:
the lean/rich liquid heat exchanger is used for exchanging heat between the rich liquid flowing out of the ethylene oxide absorption tower and the lean liquid flowing out of the ethylene oxide desorption tower; a rich liquid outlet of the ethylene oxide absorption tower is communicated with a rich liquid heat exchange channel inlet of the lean/rich liquid heat exchanger, and a rich liquid heat exchange channel outlet of the lean/rich liquid heat exchanger is communicated with a rich liquid inlet of the ethylene oxide desorption tower;
and the waste heat recovery device is arranged at the downstream of the lean/rich liquid heat exchanger and is used for recovering the heat of the lean liquid flowing out of the lean/rich liquid heat exchanger so as to reduce the temperature of the lean liquid to the temperature required by the ethylene oxide absorption tower.
Optionally, the waste heat recovery device at least comprises an absorption refrigeration unit, a driving heat source inlet of the absorption refrigeration unit is communicated with a lean liquid heat exchange channel outlet of the lean/rich liquid heat exchanger, and a lean liquid channel outlet of the absorption refrigeration unit can be communicated with a tower top inlet of the ethylene oxide absorption tower; and the barren liquor heat exchange channel inlet of the barren liquor/rich liquor heat exchanger is communicated with the barren liquor outlet of the ethylene oxide desorption tower.
Optionally, the waste heat recovery device further comprises a circulating water cooler for exchanging heat between the cooling water flowing through the waste heat recovery device and the lean solution flowing through the waste heat recovery device; the outlet of a lean solution heat exchange channel of the lean/rich solution heat exchanger is communicated with a first branch pipeline and a second branch pipeline which are arranged in parallel, the absorption type refrigerating unit is arranged on the first branch pipeline, and the circulating water cooler is arranged on the second branch pipeline; and flow control valves are arranged on the first branch pipeline and the second branch pipeline.
Optionally, the waste heat recovery device further includes an auxiliary heat exchanger, which is disposed in the first branch pipeline and located in an outlet pipeline of a barren solution heat exchange channel of the absorption refrigeration unit, and the auxiliary heat exchanger is configured to exchange heat between barren solution after heat exchange by the absorption refrigeration unit and cold water produced by the absorption refrigeration unit.
Optionally, the system further comprises a tower top pumping component, which is used for pumping the barren solution flowing out after the heat exchange of the auxiliary heat exchanger to a tower top inlet of the ethylene oxide absorption tower, or/and is used for pumping the barren solution after the heat exchange of the circulating water cooler to a tower top inlet of the ethylene oxide absorption tower.
Optionally, the temperature of the rich liquid flowing out of the ethylene oxide absorption tower is usually in the range of 90 ℃ to 125 ℃ after heat exchange by the lean/rich liquid heat exchanger; the temperature of the barren solution flowing out of the ethylene oxide desorption tower is generally 50 ℃ to 80 ℃ after heat exchange of the barren solution and the barren solution in the barren/rich solution heat exchanger; the temperature range of cold water produced by the absorption refrigerating unit taking the lean solution flowing out of the lean/rich solution heat exchanger as a heat source is 18-28 ℃.
Optionally, the temperature of the rich liquid flowing out of the ethylene oxide absorption tower is usually in the range of 90 ℃ to 125 ℃ after heat exchange by the lean/rich liquid heat exchanger; the temperature of the barren solution flowing out of the ethylene oxide desorption tower is generally 50 ℃ to 80 ℃ after heat exchange of the barren solution and the barren solution in the barren/rich solution heat exchanger; and after the lean solution flowing out of the lean/rich solution heat exchanger exchanges heat with the absorption refrigerating unit, the temperature is reduced to 25-33 ℃.
The invention also provides an EO/EG device, which comprises an ethylene oxide absorption tower, an ethylene oxide analysis tower, an analysis tower top cooler and an analysis tower reflux tank, wherein the inlet of the analysis tower top cooler is communicated with a gas overflow outlet at the top of the ethylene oxide analysis tower, the outlet of the analysis tower reflux tank is communicated with a tower top liquid reflux port of the ethylene oxide analysis tower, and the system for reducing the temperature of the ethylene oxide absorption liquid in the EO/EG device also comprises any one of the systems.
In addition, the present invention provides a method for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG unit, the method comprising:
exchanging heat between the lean solution flowing out of the ethylene oxide desorption tower and the rich solution flowing out of the ethylene oxide absorption tower through a lean/rich solution heat exchanger, and introducing the rich solution after heat exchange into the ethylene oxide desorption tower;
the lean solution subjected to heat exchange by the lean/rich solution heat exchanger is used as a heat source of the absorption refrigerating unit, and the temperature after heat exchange by the waste heat recovery device is approximately reduced to the temperature required by the ethylene oxide absorption tower;
and conveying the barren solution subjected to heat exchange by the waste heat recovery device to the top of the ethylene oxide absorption tower.
Optionally, at least part of the barren solution after heat exchange by the barren/rich solution heat exchanger is used as a heat source of the waste heat recovery device to prepare 18-28 ℃ cold water, the prepared 18-28 ℃ cold water is used for cooling the barren solution flowing out of the waste heat recovery device again to obtain barren solution with required temperature, and finally the barren solution is pumped to the top of the ethylene oxide absorption tower.
The EO/EG device of the present invention including any one of the systems and methods described above is implemented on the basis of the above-described system, and therefore, the EO/EG device and the method also have the technical effects of the above-described method.
Drawings
FIG. 1 is a schematic diagram of a prior art EO/EG plant;
FIG. 2 is a schematic diagram of an EO/EG plant in accordance with an embodiment of the invention;
FIG. 3 is a schematic diagram of an EO/EG plant in another embodiment of the invention.
Wherein, the one-to-one correspondence between reference numbers and components in fig. 1 is as follows:
a 1-ethylene oxide absorber; 2-a resolution tower; 3-resolving tower top cooler; 4-a reflux tank of the desorption tower; 5-a reflux pump; 6-a reboiler of the stripper column; 7-absorption refrigerator; 8-lean/rich liquor heat exchanger; 9-circulating water cooler;
wherein the one-to-one correspondence between reference numbers and components in fig. 2-3 is as follows:
an 11-ethylene oxide absorber; a 12-ethylene oxide stripper; 13-lean/rich liquor heat exchanger; 14-a waste heat recovery device; 141-absorption chiller units; 142-an auxiliary heat exchanger; 15-a circulating water cooler; 16-overhead pumping means; 17-overhead pumping means; 18-resolution overhead cooler; 19-a reflux tank of the desorption tower; 21-a stripper reflux pump; 20-stripper reboiler.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.
Referring to FIGS. 2 and 3, FIG. 2 is a schematic diagram of an EO/EG device in accordance with one embodiment of the present invention; FIG. 3 is a schematic diagram of an EO/EG plant in another embodiment of the invention. The flow paths of the rich liquid and the lean liquid through the lean/rich heat exchanger 13 are shown in fig. 2 and 3.
The invention provides an EO/EG device, which comprises an ethylene oxide absorption tower 11, an ethylene oxide analysis tower 12, an analysis tower top cooler 18, an analysis tower reflux tank 19 and an analysis tower reflux pump 21, wherein the inlet of the analysis tower top cooler 18 is communicated with a gas overflow outlet at the tower top of the ethylene oxide analysis tower 12, and the outlet of the analysis tower reflux pump 21 is communicated with a tower top liquid reflux port of the ethylene oxide analysis tower 12.
The tower bottom of the ethylene oxide desorption tower 12 is also provided with a desorption tower reboiler 20, and the specific structure and the function are the same as those of the prior art.
The structures of the desorption tower top cooler 18, the desorption tower reflux tank 19 and the desorption tower reflux pump 21 in the invention are the same as the prior art, and are not described herein.
The EO/EG plant also includes a system for reducing the temperature of the ethylene oxide absorption liquid in the EO/EG plant, which includes a lean/rich heat exchanger 13 and a waste heat recovery unit.
The EO and EG in the invention have the following specific meanings: ethylene oxide (EO for short), ethylene glycol (EG for short). The connection relationship among the above components in the present invention is as follows:
the lean/rich liquid heat exchanger 13 is used for exchanging heat between the rich liquid flowing out of the ethylene oxide absorption tower 11 and the lean liquid flowing out of the ethylene oxide desorption tower 12; that is, the rich liquid outlet of the ethylene oxide absorption tower 11 is communicated with the rich liquid heat exchange channel inlet of the lean/rich liquid heat exchanger 13, and the rich liquid heat exchange channel outlet of the lean/rich liquid heat exchanger 13 is communicated with the rich liquid inlet of the ethylene oxide desorption tower 12. The outlet temperature of the rich liquid from the ethylene oxide absorption tower 11 is usually about fifty degrees celsius, and the temperature of the lean liquid from the ethylene oxide desorption tower 12 is usually about one hundred degrees celsius. A waste heat recovery device for recovering heat of the lean liquid flowing out of the lean/rich liquid heat exchanger 13 to lower the temperature of the lean liquid to the temperature required by the ethylene oxide absorption tower 11 is provided downstream of the lean/rich liquid heat exchanger 13.
The temperature of ethylene oxide required for the ethylene oxide absorber 11 is generally relatively low.
As can be seen from the above description, after the lean solution flows out of the ethylene oxide stripping tower 12, the lean solution in the present invention exchanges heat with the rich solution in the lean/rich solution heat exchanger 13, so the temperature of the lean solution during heat exchange is relatively high, usually about 118 ℃, so that the amount of heat transferred to the rich solution by the lean solution is large, the rich solution is raised to a higher temperature, the temperature of the rich solution entering the ethylene oxide stripping tower 12 is raised, and accordingly, the amount of heat of the high-grade heat source of the stripping tower reboiler 20 to be consumed is greatly reduced; and the heat quantity of the lean solution conveyed to the rich solution in the lean/rich solution heat exchanger 13 is large, and the heat quantity which needs to be taken away by cooling water in a subsequent waste heat recovery device is correspondingly small, so that the water consumption and the power consumption of the cooling water are saved.
In addition, the system provided by the invention can change the connecting pipelines among all the parts on the basis of the original parts of the system in the prior art, realize that rich liquor and lean liquor firstly carry out heat exchange in the lean/rich liquor heat exchanger 13, has small damage to the original system and reduces the reconstruction cost.
The waste heat recovery device utilizes cooling water to cool the barren solution. The cooling water in this context is a broad concept, not an absolute water, and may be any liquid capable of performing a cooling function.
In a specific embodiment, the waste heat recovery device at least comprises an absorption refrigeration unit 141, a lean liquid outlet of the ethylene oxide desorption tower 12 is communicated with a lean liquid heat exchange channel inlet of the lean/rich liquid heat exchanger 13, a driving heat source inlet of the absorption refrigeration unit 141 is communicated with a lean liquid heat exchange channel outlet of the lean/rich liquid heat exchanger 13, and a lean liquid channel outlet of the absorption refrigeration unit 141 is connected with a tower top inlet of the ethylene oxide absorption tower 11. It should be noted that the communication here is a broad concept, and may be a direct communication between the absorption refrigerator group 141 and the ethylene oxide absorption column 11, or may be an indirect communication between the absorption refrigerator group 141 and the ethylene oxide absorption column 11.
Further, the waste heat recovery device may further include a circulating water cooler 15 for exchanging heat between the cold water flowing through the interior thereof and the lean solution flowing through the interior thereof; the lean solution heat exchange channel outlet of the lean/rich solution heat exchanger 13 is communicated with a first branch pipeline and a second branch pipeline which are arranged in parallel, the absorption type refrigerating unit 141 is arranged on the first branch pipeline, and the circulating water cooler 15 is arranged on the second branch pipeline.
The inside of the circulating water cooler is provided with a cooling water channel and a barren liquor channel, and the cooling water and the barren liquor realize heat exchange in the flowing process inside the circulating water cooler 15, so that the temperature of the barren liquor is further reduced. The structure of the circulating water cooler is not described in detail herein, and please refer to the prior art as long as the above heat exchange effect can be achieved.
In the above embodiment, set up first branch pipeline and second branch pipeline, can all set up flow control valve on first branch pipeline and second branch pipeline, adjust the barren liquor flow who flows through first branch pipeline and second branch pipeline, and then improve system and use the flexibility to satisfy the demand of different operating modes.
For example, the above embodiment may only communicate with the first branch pipeline and only start the waste heat recovery device to cool the lean solution, or may only communicate with the second branch pipeline and only start the circulating water cooler 15 to cool the lean solution; of course, the second branch pipeline and the first branch pipeline may be communicated at the same time, and the two lean liquids may be cooled by the waste heat recovery device and the circulating water cooler 15 at the same time.
On the basis of the above embodiment, the system provided by the present invention further includes an overhead pumping unit 16, configured to pump the lean solution after the absorption refrigeration unit 141 exchanges heat with the circulating water cooler 15 to the overhead inlet of the ethylene oxide absorption tower 11.
The embodiment is provided with the tower top pumping part 16 to provide liquid flowing power, so that the fluid movement fluency is ensured, and the heat exchange efficiency is ensured.
In one embodiment, the temperature of the rich liquid flowing out of the ethylene oxide absorption tower is generally in the range of 90 ℃ to 125 ℃ after heat exchange in the lean/rich liquid heat exchanger 13; the lean solution flowing out of the ethylene oxide desorption tower 12 is subjected to heat exchange by a lean/rich solution heat exchanger 13, and the temperature range is usually 50 ℃ to 80 ℃; the lean solution flowing out of the lean/rich solution heat exchanger 13 is subjected to heat exchange by the absorption refrigeration unit, and then the temperature is reduced to 25-33 ℃.
Experiments prove that the system meeting the heat exchange conditions consumes lower energy.
In another specific embodiment, the waste heat recovery device further includes an auxiliary heat exchanger 142 disposed in the first branch pipeline and located at the lean solution heat exchange channel outlet pipeline of the waste heat recovery device, for exchanging heat between the lean solution after heat exchange by the waste heat recovery device and the cold water produced by the waste heat recovery device.
In this embodiment, the lean solution after heat exchange in the lean/rich solution heat exchanger 13 is cooled by the absorption refrigeration unit 141, and then the lean solution is cooled again by using the cold water produced by the absorption refrigeration unit 141, so as to obtain ethylene oxide at the temperature required by the ethylene oxide absorption tower 11.
In one embodiment, the temperature of the rich liquid flowing out of the ethylene oxide absorption tower is generally in the range of 90 ℃ to 125 ℃ after heat exchange in the lean/rich liquid heat exchanger 13; the lean solution flowing out of the ethylene oxide desorption tower 12 is subjected to heat exchange by the lean/rich solution heat exchanger 13, and the temperature range is usually 50 ℃ to 80 ℃; the temperature range of cold water produced by the absorption refrigerating unit taking the lean solution flowing out of the lean/rich solution heat exchanger 13 as a heat source is 18 ℃ to 28 ℃.
Experiments prove that the system meeting the temperature conditions has low energy consumption.
On the basis of the above embodiment, it is also possible to include an overhead pumping part 16 for pumping the lean liquid flowing out after the heat exchange by the auxiliary heat exchanger 142 and the lean liquid flowing out after the heat exchange by the circulating water cooler 15 to the overhead inlet of the ethylene oxide absorption tower 11.
The function of the overhead pumping section 16 is the same as described above and will not be described in detail here.
In one embodiment, a tower bottom pumping part 17 is further arranged between the lean liquid outlet of the ethylene oxide desorption tower 12 and the lean liquid heat exchange channel inlet of the lean/rich liquid heat exchanger 13, and is used for providing liquid flow power.
The waste heat recovery device herein is not limited to the structure described herein as long as the above-described function can be achieved.
On the basis of the system, the invention also provides a method for reducing the temperature of ethylene oxide absorption liquid in an EO/EG device, which comprises the following steps:
exchanging heat between the lean solution flowing out of the ethylene oxide desorption tower 12 and the rich solution flowing out of the ethylene oxide absorption tower 11 through a lean/rich solution heat exchanger 13, and introducing the rich solution after heat exchange into the ethylene oxide desorption tower 12;
wherein, the temperature of the rich liquid flowing out from the ethylene oxide absorption tower 11 can be approximately 90 ℃ to 125 ℃ after the heat exchange of the lean/rich liquid heat exchanger 13;
the barren solution after heat exchange of the barren/rich solution heat exchanger 13 enters a waste heat recovery device 14, and the temperature after heat exchange of the waste heat recovery device 14 is approximately reduced to 25-33 ℃;
the lean liquid after heat exchange by the absorption refrigerator group 141 is pumped to the top of the ethylene oxide absorption tower 11.
In a specific embodiment, the lean solution after heat exchange in the lean/rich solution heat exchanger 13 is divided into two parts, wherein one part is used as a heat source of the waste heat recovery device 14, for example, when the waste heat recovery device 14 comprises an absorption refrigeration unit 141, the lean solution can be used as a heat source of the absorption refrigeration unit 141 to prepare cold water at 18 ℃ to 28 ℃, and the lean solution flowing out of the absorption refrigeration unit 141 is cooled again by using the prepared cold water at 18 ℃ to 28 ℃ to obtain the lean solution at a desired temperature, and finally the lean solution is conveyed to the top of the ethylene oxide absorption tower 11.
The method for reducing the temperature of the ethylene oxide absorption liquid in the EO/EG device provided by the invention is implemented on the basis of the system for reducing the temperature of the ethylene oxide absorption liquid in the EO/EG device, and the EO/EG device comprises the system, so the method and the EO/EG device also have the technical effects of the system, and the details are not repeated herein.
It should be noted that "connect" and "communicate" as used herein are all broad concepts, and may be a direct connection or communication between two components, and two components may be connected or connected through an intermediate component.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.
Claims (10)
1. A system for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG unit, comprising:
a lean/rich liquid heat exchanger (13) for exchanging heat between the rich liquid flowing out of the ethylene oxide absorption tower (11) and the lean liquid flowing out of the ethylene oxide desorption tower (12); a rich liquid outlet of the ethylene oxide absorption tower (11) is communicated with a rich liquid heat exchange channel inlet of the lean/rich liquid heat exchanger (13), and a rich liquid heat exchange channel outlet of the lean/rich liquid heat exchanger (13) is communicated with a rich liquid inlet of the ethylene oxide desorption tower (12);
a waste heat recovery device (14) is arranged at the downstream of the lean/rich liquid heat exchanger (13), and the waste heat recovery device (14) is used for recovering the heat of the lean liquid flowing out of the lean/rich liquid heat exchanger (13) so as to reduce the temperature of the lean liquid to the temperature required by the ethylene oxide absorption tower (11).
2. The system for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG plant as claimed in claim 1, wherein the waste heat recovery device (14) comprises at least an absorption chiller unit, a driving heat source inlet of the absorption chiller unit is communicated with a lean liquid heat exchange passage outlet of the lean/rich liquid heat exchanger (13), and a lean liquid passage outlet of the absorption chiller unit is communicated with a tower top inlet of the ethylene oxide absorption tower (11); and the lean solution heat exchange channel inlet of the lean/rich solution heat exchanger (13) is communicated with the lean solution outlet of the ethylene oxide desorption tower (12).
3. The system for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG plant as set forth in claim 2, wherein the waste heat recovery unit (14) further comprises a circulating water cooler (15) for heat exchanging cooling water flowing therethrough with the lean liquid flowing therethrough; the outlet of a lean solution heat exchange channel of the lean/rich solution heat exchanger (13) is communicated with a first branch pipeline and a second branch pipeline which are arranged in parallel, the absorption type refrigerating unit is arranged on the first branch pipeline, and the circulating water cooler (15) is arranged on the second branch pipeline; and flow control valves are arranged on the first branch pipeline and the second branch pipeline.
4. The system for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG plant as set forth in claim 3, wherein the waste heat recovery unit (14) further comprises an auxiliary heat exchanger (142) disposed in the first branch line and located at the lean liquid heat exchange passage outlet line of the absorption chiller unit, the auxiliary heat exchanger (142) being configured to exchange heat between the lean liquid after heat exchange by the absorption chiller unit and the cold water produced by the absorption chiller unit.
5. The system for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG plant as set forth in claim 4, further comprising an overhead pumping part (17) for pumping the lean liquid discharged after heat exchange by the auxiliary heat exchanger (142) to an overhead inlet of the ethylene oxide absorption column (11), or/and for pumping the lean liquid after heat exchange by the circulating water cooler (15) to an overhead inlet of the ethylene oxide absorption column (11).
6. The system for reducing the temperature of the ethylene oxide absorption liquid in an EO/EG plant as set forth in claim 4, wherein the temperature of the rich liquid flowing out of the ethylene oxide absorption tower (11) is generally in the range of 90 ℃ to 125 ℃ after heat exchange in the lean/rich heat exchanger (13); the temperature of the lean solution flowing out of the ethylene oxide desorption tower (12) is generally in the range of 50 ℃ to 80 ℃ after heat exchange by the lean/rich solution heat exchanger (13); the temperature range of cold water produced by the absorption refrigerating unit taking the lean solution flowing out of the lean/rich solution heat exchanger (13) as a heat source is 18-28 ℃.
7. The system for reducing the temperature of the ethylene oxide absorption liquid in an EO/EG plant as set forth in claim 1, wherein the temperature of the rich liquid flowing out of the ethylene oxide absorption tower (11) is generally in the range of 90 ℃ to 125 ℃ after heat exchange in the lean/rich heat exchanger (13); the temperature of the lean solution flowing out of the ethylene oxide desorption tower (12) is generally in the range of 50 ℃ to 80 ℃ after heat exchange by the lean/rich solution heat exchanger (13); the temperature of the barren solution flowing out of the barren/rich solution heat exchanger (13) is reduced to 25-33 ℃ after heat exchange of the absorption refrigerating unit.
8. An EO/EG plant comprising an ethylene oxide absorber (11), an ethylene oxide stripper column (12), a stripper overhead cooler (18) and a stripper reflux drum (19), the inlet of the stripper overhead cooler (18) being in communication with a gas overflow outlet at the top of the ethylene oxide stripper column (12), and the outlet of the stripper reflux drum (19) being in communication with a liquid reflux outlet at the top of the ethylene oxide stripper column (12), characterised in that it further comprises a system for reducing the temperature of an ethylene oxide absorber liquid in an EO/EG plant as claimed in any one of claims 1 to 7.
9. A method for reducing the temperature of an ethylene oxide absorption liquid in an EO/EG unit, the method comprising:
exchanging heat between a lean solution flowing out of an ethylene oxide desorption tower (12) and a rich solution flowing out of an ethylene oxide absorption tower (11) through a lean/rich solution heat exchanger (13), and introducing the rich solution after heat exchange into the ethylene oxide desorption tower (12);
the temperature of the barren solution after heat exchange of the barren solution/rich solution heat exchanger (13) is approximately reduced to the temperature required by the ethylene oxide absorption tower (11) after heat exchange of the waste heat recovery device (14);
and the barren solution after heat exchange by the waste heat recovery device (14) is conveyed to the top of the ethylene oxide absorption tower (11).
10. The method for reducing the temperature of the ethylene oxide absorption liquid in the EO/EG plant as claimed in claim 9, characterized in that the barren liquid after heat exchange in the lean/rich liquid heat exchanger (13) is at least partially used as the heat source of the waste heat recovery device (14) to prepare the cold water at 18-28 ℃, and the barren liquid flowing out of the waste heat recovery device (14) is cooled again by using the prepared cold water at 18-28 ℃ to obtain the barren liquid at the required temperature, and finally pumped to the top of the ethylene oxide absorption tower (11).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010175413.9A CN111233793A (en) | 2020-03-13 | 2020-03-13 | System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010175413.9A CN111233793A (en) | 2020-03-13 | 2020-03-13 | System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111233793A true CN111233793A (en) | 2020-06-05 |
Family
ID=70877006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010175413.9A Pending CN111233793A (en) | 2020-03-13 | 2020-03-13 | System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111233793A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114543576A (en) * | 2022-01-25 | 2022-05-27 | 中建石化工程有限公司 | System and method for utilizing waste heat of byproduct steam of coal-to-ethylene glycol device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1513825A (en) * | 2002-12-31 | 2004-07-21 | 北京化工大学 | Dimethyl ether separation technological method |
| CN104974113A (en) * | 2014-04-02 | 2015-10-14 | 中国石油化工股份有限公司 | System and method for cooling ethylene oxide absorption water on EO/EG device |
| CN107983092A (en) * | 2017-12-22 | 2018-05-04 | 上海齐耀热能工程有限公司 | Residual neat recovering system and exhaust heat recovering method |
| CN108744893A (en) * | 2018-07-12 | 2018-11-06 | 华中农业大学 | CO based on heat pipe intensified recuperation of heat2Chemical absorbing System and method for |
| CN211847755U (en) * | 2020-03-13 | 2020-11-03 | 荏原冷热系统（中国）有限公司 | System for be used for reducing ethylene oxide absorbed liquid temperature in EO/EG device and EO/EG device |
-
2020
- 2020-03-13 CN CN202010175413.9A patent/CN111233793A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1513825A (en) * | 2002-12-31 | 2004-07-21 | 北京化工大学 | Dimethyl ether separation technological method |
| CN104974113A (en) * | 2014-04-02 | 2015-10-14 | 中国石油化工股份有限公司 | System and method for cooling ethylene oxide absorption water on EO/EG device |
| CN107983092A (en) * | 2017-12-22 | 2018-05-04 | 上海齐耀热能工程有限公司 | Residual neat recovering system and exhaust heat recovering method |
| CN108744893A (en) * | 2018-07-12 | 2018-11-06 | 华中农业大学 | CO based on heat pipe intensified recuperation of heat2Chemical absorbing System and method for |
| CN211847755U (en) * | 2020-03-13 | 2020-11-03 | 荏原冷热系统（中国）有限公司 | System for be used for reducing ethylene oxide absorbed liquid temperature in EO/EG device and EO/EG device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114543576A (en) * | 2022-01-25 | 2022-05-27 | 中建石化工程有限公司 | System and method for utilizing waste heat of byproduct steam of coal-to-ethylene glycol device |
| CN114543576B (en) * | 2022-01-25 | 2023-08-18 | 中建石化工程有限公司 | Byproduct steam waste heat utilization system and method for coal-to-ethylene glycol device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103307715B (en) | Air-conditioner, the cooling system of air-conditioner and cooling means | |
| CN202521938U (en) | Heat pump system and drying system | |
| CN109032201A (en) | Semiconductor production temperature control device | |
| CN103868265A (en) | Temperature control device with cold accumulation/heat accumulation function | |
| CN211847755U (en) | System for be used for reducing ethylene oxide absorbed liquid temperature in EO/EG device and EO/EG device | |
| CN111233793A (en) | System and method for reducing temperature of ethylene oxide absorption liquid in EO/EG device and EO/EG device | |
| CN102364321B (en) | System for testing cooling and heating capacity of water source heat pump unit | |
| CN107764122B (en) | Large-temperature-difference cold water combined type cascade utilization system based on waste heat utilization | |
| CN201945083U (en) | Water chilling unit | |
| CN108507212B (en) | Jet flow two-phase heat exchange pump auxiliary system | |
| CN105576943B (en) | A kind of high voltage direct current converter valve heat recovery system and its implementation | |
| CN104180555B (en) | A kind of cold dual effect type lithium bromide jet suction type cooling cycle system | |
| CN104390412A (en) | Cooling system for slicing machine process water | |
| CN207247612U (en) | A kind of water route coupling cascade formula low-temperature air-cooling heat pump system | |
| CN203911671U (en) | Hydropower station unit energy conservation and environment protection phase change cooling device | |
| CN103542592A (en) | Direct combustion type lithium bromide absorption cold and hot water unit with heat recycling function | |
| CN210624991U (en) | Energy-saving device for high-temperature water production | |
| CN205808193U (en) | Efficiently plate-fin heat exchanger | |
| CN207006908U (en) | A kind of space division technique circulating cooling system | |
| CN114717576B (en) | Hydrogen production system and alkali liquor circulation method | |
| CN203719222U (en) | Temperature control device with functions of cool storage and heat storage | |
| CN220867467U (en) | Quenching water quick cooling device of solution furnace | |
| CN114838539B (en) | Circulating refrigerating fluid switching and supplying device for severe cold region and using method | |
| CN208161077U (en) | A kind of device for carbon disulfide rectifying | |
| CN212832861U (en) | Ammonia water preparation device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |