Methanol preheating device for MTO device
By designing a parallel heat exchanger and improving heat exchange, the problems of poor methanol preheating effect and insufficient waste heat utilization in the MTO unit were solved, thereby improving the methanol preheating effect, reducing energy consumption, and lowering raw material costs.
Patent Information
- Application Number
- CN202423094874.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-16
AI Technical Summary
In existing MTO units, the methanol preheating effect is poor and the waste heat utilization rate is insufficient, which leads to limited methanol feed load and high energy consumption. Furthermore, the water content increases when using MTO-grade methanol, which in turn affects the feed load and energy consumption.
The system employs a parallel heat exchanger design, including a condensate tank, heat exchangers, and pumps. It exchanges heat between low-pressure steam condensate and purified water to increase the methanol preheating temperature, recover waste heat within the system, reduce purified water consumption, avoid water hammer, and improve the methanol preheating effect.
It improved the methanol preheating effect, enhanced the system waste heat utilization rate, reduced the vaporizer load and energy consumption, reduced raw material costs, and realized the effective use of methanol with high water content.
Smart Images
Figure CN223570660U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the methanol preheating field, specifically to a methanol preheating device for MTO device. BACKGROUND
[0002] MTO device uses liquid phase methanol as raw material, vaporizes through heat exchange device and methanol-stripping gas heat exchanger, and after vaporization, methanol enters the reactor, in the prior art, in order to consider economic benefits, methanol feeding load in the industry is generally controlled at above 120%, and considering energy consumption and raw material cost saving of upstream and downstream devices, MTO grade methanol is adopted, and water content in MTO grade methanol is increased by about 5% than that in refined methanol, thereby causing the situation that methanol-steam vaporizer heat exchanger appears feeding load limitation under high load, high water content and low temperature weather; in addition, in the prior art, the waste heat utilization rate of MTO device is insufficient, if the waste heat in the system can be recovered through effective means and the methanol preheating temperature is increased, the situation of MTO grade methanol load limitation can be alleviated, methanol use cost can be reduced, device energy consumption can be saved, and marginal benefit of device production can be improved. SUMMARY
[0003] In view of the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a methanol preheating device for MTO device, which can improve methanol preheating effect, improve system waste heat utilization rate, and reduce vaporizer load and energy consumption.
[0004] In order to solve the above problems, the utility model provides the following technical scheme:
[0005] A methanol preheating device for MTO device, the preheating device comprises at least one condensate tank one in a sewage stripping system, the water outlet end of the condensate tank one is communicated with the water inlet end of a condensate tank two through parallel pipelines one and two, a heat exchanger one is communicated with the pipeline two, the water outlet end of the condensate tank two is communicated with the water inlet end of a heat exchanger two through a pump, and the water outlet end of the heat exchanger two is communicated with a condensate outlet device; the preheating device further comprises heat exchangers three and four arranged in parallel, the water inlet end of the heat exchangers three and four is communicated with a purified water inlet device, and the water outlet end of the heat exchangers three and four is communicated with a purified water outlet device; a methanol feeding device comprises a raw material methanol preheating pipeline, the preheating pipeline is provided with parallel pipelines three and four, the pipeline three is communicated with the methanol feeding end of the heat exchanger three, the pipeline four is communicated with the methanol feeding end of the heat exchanger four, the methanol outlet ends of the pipelines three and four are communicated with the methanol feeding end of the heat exchanger two after being merged, and the preheating pipeline of the methanol outlet end of the heat exchanger two is communicated with the feeding end of a vaporizer; the pipelines one, two, three and four are all provided with valves.
[0006] It should be noted that the sewage stripping device is an important device for treating wastewater in an MTO (methanol to olefins) device and produces low-pressure steam condensate.
[0007] The heat exchanger three and the heat exchanger four are designed in parallel, can be used in parallel or individually, and together with the heat exchanger two using waste heat recovery for heat exchange, the preheating temperature of the raw material methanol is improved, and the amount of purified water is reduced.
[0008] The technical scheme of the utility model further includes that a wall attachment valve is arranged on the pipeline of the water inlet end of the condensate tank two, and the wall attachment valve can stabilize the condensate temperature in the condensate tank two
[0009] As preferred, the technical scheme of the utility model further includes that the wall attachment valve is one of a ball valve, a butterfly valve, a gate valve and a pendulum valve.
[0010] The technical scheme of the utility model further includes that the heat exchanger one is connected with a cooling circulation device, and the heat exchanger one is used for cooling the high-temperature low-pressure steam condensate to avoid water hammer in the condensate tank two.
[0011] Further, the technical scheme of the utility model further includes that the heat exchanger one is one of a shell-and-tube condenser and a plate-type condenser.
[0012] The technical scheme of the utility model further includes that the heat exchanger two, the heat exchanger three and the heat exchanger four are one of a tube-and-shell heat exchanger, a plate-type heat exchanger and a double-pipe heat exchanger.
[0013] The methanol preheating method using the above device is as follows: the low-pressure steam condensate of the sewage stripping system is stored in the condensate tank one and then enters the pipeline one and / or the pipeline two, and then enters the condensate tank two; the low-pressure steam condensate in the pipeline two is cooled by the heat exchanger one and then enters the condensate tank two; the high-temperature condensate in the condensate tank two is pumped to the heat exchanger two by a pump; the raw material methanol first exchanges heat with the high-temperature purified water in the heat exchanger three and / or the heat exchanger four through the preheating pipeline, and then exchanges heat with the high-temperature condensate in the heat exchanger two, and finally, the raw material methanol enters the vaporizer and is treated to obtain gas-phase methanol.
[0014] The utility model has the advantages of:
[0015] The utility model discloses a MTO device methanol preheating device that improves methanol preheating effect, improves system waste heat utilization rate and reduces vaporizer load and energy consumption compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, for the ordinary skilled person in the art, without the premise of creating the labor, can also obtain other drawings according to these drawings.
[0017] Figure 1 It is the schematic diagram of MTO device methanol preheating device in specific implementation.
[0018] Wherein, 1 is condensate tank one, 2 is pipeline one, 3 is pipeline two, 4 is condensate tank two, 5 is wall valve, 6 is heat exchanger one, 7 is pump machine, 8 is heat exchanger two, 9 is heat exchanger three, 10 is heat exchanger four, 11 is preheating pipeline, 12 is pipeline three, 13 is pipeline four, 14 is vaporizer, 15 is valve. DETAILED DESCRIPTION
[0019] In order to make the person in the art better understand the technical scheme in the utility model, the following will combine the drawings in the embodiment of the utility model, and the technical scheme in the embodiment of the utility model is clearly and completely described, obviously, the described embodiment only is a part of the embodiment of the utility model, and is not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skilled person in the art without the premise of creating the labor should belong to the scope of the protection of the utility model.
[0020] In the description of the utility model, it is understood that the terms "center", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of simplifying the description of the utility model, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.
[0021] As can be seen from the drawings, a methanol preheating device for MTO device, the preheating device includes two condensate tanks 1 in the sewage stripping system, the water outlet end of the condensate tank 1 is communicated with the water inlet end of the condensate tank 2 4 through the parallel pipeline 2 and the pipeline 3, and the pipeline of the water inlet end of the condensate tank 2 4 is provided with a wall valve 5.
[0022] The pipeline 3 is communicated with a heat exchanger 6, the heat exchanger 6 is a shell and tube condenser, the heat exchanger 6 is communicated with a cooling circulating device, the water outlet end of the condensate tank 2 4 is communicated with the water inlet end of the heat exchanger 2 8 through a pump 7, and the water outlet end of the heat exchanger 2 8 is communicated with a condensate outlet device.
[0023] The preheating device further includes a heat exchanger 3 9 and a heat exchanger 4 10 arranged in parallel, the water inlet end of the heat exchanger 3 9 and the heat exchanger 4 10 is communicated with a purified water inlet device, and the water outlet end of the heat exchanger 3 9 and the heat exchanger 4 10 is communicated with a purified water outlet device.
[0024] The methanol feeding device includes a preheating pipeline 11 of raw methanol, the preheating pipeline 11 is provided with a parallel pipeline 3 12 and a pipeline 4 13, the pipeline 3 12 is communicated with the methanol feeding end of the heat exchanger 3 9, the pipeline 4 13 is communicated with the methanol feeding end of the heat exchanger 4 10, the methanol outlet end of the pipeline 3 12 and the pipeline 4 13 is merged and communicated with the methanol feeding end of the heat exchanger 2 8, and the preheating pipeline 11 of the methanol outlet end of the heat exchanger 2 8 is communicated with the feeding end of the vaporizer 14. The pipeline 2, the pipeline 3, the pipeline 3 12 and the pipeline 4 13 are all provided with valves 15.
[0025] The methanol preheating method using the above device, the low-pressure steam condensate of the sewage stripping system is stored in the condensate tank 1 and then enters the pipeline 2 and the pipeline 3, and then enters the condensate tank 2 4, the low-pressure steam condensate through the pipeline 3 is cooled by the heat exchanger 6 and then enters the condensate tank 2 4, and the high-temperature condensate in the condensate tank 2 4 is pumped to the heat exchanger 2 8 by the pump 7; the raw methanol first exchanges heat with the high-temperature purified water in the heat exchanger 3 9 and the heat exchanger 4 10 through the preheating pipeline 11, then enters the heat exchanger 2 8 and exchanges heat with the high-temperature condensate in the heat exchanger 2 8, and finally, the raw methanol enters the vaporizer 14 and is treated to obtain gaseous methanol.
[0026] The device can effectively improve the preheating effect of raw material methanol, realize the recycling of condensate heat and purification water system heat in the MTO device system in the liquid phase methanol feeding process, effectively reduce the load of the vaporizer, reduce the steam energy consumption, realize the use of MTO grade high water content methanol, and reduce the raw material cost and energy consumption.
[0027] Although the utility model has been described in detail by referring to the drawings and combining the preferred embodiments, the utility model is not limited to this. The ordinary skilled in the art can make various equivalent modifications or replacements to the embodiments of the utility model without departing from the spirit and essence of the utility model, and these modifications or replacements should be within the scope of the utility model, any skilled in the art can easily think of changes or replacements within the technical range disclosed by the utility model, and these changes or replacements should be within the protection scope of the utility model. Therefore, the protection scope of the utility model should be subject to the protection scope of the claims.
Claims
1. A methanol preheating device for MTO unit, characterized in that: The preheating device comprises at least one condensate tank one in a sewage stripping system, a water outlet end of the condensate tank one is communicated with a water inlet end of a condensate tank two through parallel pipelines one and two, the pipeline two is communicated with a heat exchanger one, a water outlet end of the condensate tank two is communicated with a water inlet end of a heat exchanger two through a pump, a water outlet end of the heat exchanger two is communicated with a condensate outlet device; the preheating device further comprises parallel heat exchangers three and four, a water inlet end of the heat exchangers three and four is communicated with a purified water inlet device, a water outlet end of the heat exchangers three and four is communicated with a purified water outlet device; the methanol feeding device comprises a preheating pipeline of raw methanol, the preheating pipeline is provided with parallel pipelines three and four, the pipeline three is communicated with a methanol feeding end of the heat exchanger three, the pipeline four is communicated with a methanol feeding end of the heat exchanger four, the methanol feeding ends of the pipelines three and four are communicated with a methanol feeding end of the heat exchanger two after being merged, a preheating pipeline of the methanol feeding end of the heat exchanger two is communicated with a feeding end of a vaporizer; the pipelines one, two, three and four are provided with valves.
2. The methanol preheating device for MTO device according to claim 1, characterized in that: A wall-adhering valve is arranged on a pipeline of the water inlet end of the condensate tank two.
3. The methanol preheating device for MTO device according to claim 2, characterized in that: The wall-adhering valve is one of a ball valve, a butterfly valve, a gate valve and a pendulum valve.
4. The methanol preheating device for MTO device according to claim 1, characterized in that: The heat exchanger one is communicated with a cooling circulation device.
5. The methanol preheating device for MTO device according to claim 1, characterized in that: The heat exchanger one is one of a shell-and-tube condenser and a plate condenser.
6. The methanol preheating device for MTO device according to claim 1, characterized in that: The heat exchangers two, three and four are one of a tube-and-shell heat exchanger, a plate heat exchanger and a double-pipe heat exchanger.