Atmospheric tower waste heat recycling system and using method

Abstract

The invention relates to the technical field of atmospheric tower waste heat recovery, in particular to a waste heat recycling system of an atmospheric tower and a using method of the waste heat recycling system of the atmospheric tower. The circulating water heat exchanger I, the circulating water heat exchanger II and an atmospheric tower tail cooler of the atmospheric tower are all communicated with an atmospheric tower reflux tank, the atmospheric tower reflux tank is communicated with an atmospheric tower reflux pump, and a discharge port of the atmospheric tower is sequentially communicated with an atmospheric tower kettle liquid pump I and an atmospheric tower kettle liquid pump II. According to the waste heat recycling system of the atmospheric tower and the use method, through reasonable structural design and flow arrangement, effective recycling of waste heat of the atmospheric tower is achieved, energy consumption in the methanol rectification process is reduced, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery of atmospheric columns, and particularly to a waste heat recovery and utilization system for an atmospheric column and a usage method thereof. Background Art

[0002] In the methanol distillation project, a large amount of energy is consumed during the distillation process, and the rational utilization of the heat of the atmospheric column has always been the focus of attention in the industry. During the operation of the traditional atmospheric column, the waste heat of the gas phase at the top of the column and the heat of the liquid at the bottom of the column are often not fully and effectively recovered and utilized, resulting in waste of energy. On the one hand, if the large amount of heat carried by the gas phase at the top of the column is directly discharged, it will not only increase the load of the subsequent cooling equipment, but also cause this part of the available energy to be wasted; on the other hand, the liquid discharged from the bottom of the column also has a relatively high temperature. Direct discharge or unreasonable utilization of its heat is not conducive to the energy conservation and consumption reduction of the entire methanol distillation system. Therefore, developing a system that can effectively recover and utilize the waste heat of the atmospheric column is of great significance for reducing the energy consumption of the methanol distillation project and improving the energy utilization efficiency. Summary of the Invention

[0003] The purpose of the present invention is to provide a waste heat recovery and utilization system for an atmospheric column and a usage method thereof. Through reasonable structural design and process arrangement, the effective recovery and utilization of the waste heat of the atmospheric column are realized, the energy consumption during methanol distillation is reduced, and the energy utilization efficiency is improved.

[0004] To achieve the above purpose, the present invention provides a waste heat recovery and utilization system for an atmospheric column, including an atmospheric column. The gas-phase outlet at the top of the atmospheric column is respectively connected to a first circulating water heat exchanger and a second circulating water heat exchanger. The first circulating water heat exchanger, the second circulating water heat exchanger, and the tail cooler of the atmospheric column of the atmospheric column are all connected to the reflux tank of the atmospheric column. The reflux tank of the atmospheric column is connected to the reflux pump of the atmospheric column. The discharge port of the atmospheric column is successively connected to a first bottom liquid pump of the atmospheric column and a second bottom liquid pump of the atmospheric column.

[0005] Preferably, both the first bottom liquid pump of the atmospheric column and the second bottom liquid pump of the atmospheric column are connected to a first preheater of the pressurized column and a second preheater of the pressurized column. The first preheater of the pressurized column and the second preheater of the pressurized column are both connected to the bottom of the pressurized column.

[0006] Preferably, the reflux pump of the atmospheric column is respectively connected to the feed preheater and the top of the atmospheric column.

[0007] Preferably, the tail gas outlet of the tail cooler of the atmospheric column is connected to the main tail gas pipe.

[0008] Preferably, the lower part of the atmospheric column is provided with a first feed port and a second feed port, and the bottom of the atmospheric column is provided with a discharge port.

[0009] Preferably, the first preheater of the pressurized column exchanges heat with a 0.5 MPa steam condensate pipeline, and the second preheater of the pressurized column exchanges heat with a 1.0 MPa steam condensate pipeline.

[0010] The usage method of the waste heat recovery and utilization system of an atmospheric column as described above includes the following steps:

[0011] S1. The gas-phase outlet at the top of the atmospheric column enters the first circulating water heat exchanger and the second circulating water heat exchanger, and the condensate generated by the first circulating water heat exchanger and the second circulating water heat exchanger enters the reflux tank of the atmospheric column;

[0012] S2. The trapped liquid generated by the tail cooler of the atmospheric column enters the reflux tank of the atmospheric column, and the tail gas generated by the tail cooler of the atmospheric column enters the main tail gas pipe;

[0013] S3. The material of the atmospheric column enters the first atmospheric column bottom liquid pump and the second atmospheric column bottom liquid pump through the discharge port for pressurization. After pressurization, the materials enter the first preheater of the pressurized column and the second preheater of the pressurized column respectively, and finally converge and enter the bottom of the pressurized column.

[0014] Therefore, by adopting the waste heat recovery and utilization system and usage method of an atmospheric column as described above, the beneficial effects of the present invention are as follows:

[0015] 1. By setting the first circulating water heat exchanger and the second circulating water heat exchanger, the present invention can fully recover the waste heat of the gas phase at the top of the atmospheric column, convert it into utilizable condensate, reduce energy waste. At the same time, after the column bottom liquid is pressurized by the first atmospheric column bottom liquid pump and the second atmospheric column bottom liquid pump, heat exchange is carried out with the steam condensate pipeline by using the first preheater of the pressurized column and the second preheater of the pressurized column, realizing the effective recovery and utilization of the waste heat of the column bottom liquid and improving the energy utilization rate;

[0016] 2. The usage method provided by the present invention effectively recovers and utilizes waste heat, reduces the demand for external energy in the methanol rectification process, reduces energy consumption, reduces production costs, and also meets the requirements of energy conservation and environmental protection.

[0017] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0018] Figure 1 is a schematic diagram of a waste heat recovery and utilization system of an atmospheric column according to the present invention.

[0019] Reference numerals:

[0020] 1. Atmospheric column; 2. First circulating water heat exchanger; 3. Second circulating water heat exchanger; 4. Tail cooler of the atmospheric column; 5. Reflux tank of the atmospheric column; 6. Reflux pump of the atmospheric column; 7. First atmospheric column bottom liquid pump; 8. Second atmospheric column bottom liquid pump; 9. First preheater of the pressurized column; 10. Second preheater of the pressurized column; 11. Discharge port; 12. First feed port; 13. Second feed port. Detailed Embodiments

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the technical field to which the present invention pertains. The above-mentioned features mentioned in the present invention or the features mentioned in the specific examples can be combined arbitrarily. These specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0022] Embodiment 1

[0023] As Figure 1 shown, the present invention provides a waste heat recovery and utilization system for an atmospheric column, which includes an atmospheric column 1. The top gas outlet of the atmospheric column 1 is respectively connected to a first circulating water heat exchanger 2 and a second circulating water heat exchanger 3. The first circulating water heat exchanger 2, the second circulating water heat exchanger 3 and the atmospheric column tail cooler 4 of the atmospheric column 1 are all connected to an atmospheric column reflux tank 5. The atmospheric column reflux tank 5 is connected to an atmospheric column reflux pump 6. The discharge port 11 of the atmospheric column 1 is successively connected to a first atmospheric column bottom liquid pump 7 and a second atmospheric column bottom liquid pump 8.

[0024] During the rectification process, the top gas of the atmospheric column 1 flows out from the top gas outlet, and respectively enters the first circulating water heat exchanger 2 and the second circulating water heat exchanger 3 for heat exchange and cooling. The condensate generated flows into the atmospheric column reflux tank 5. The atmospheric column tail cooler 4 further processes the uncondensed gas, and the collected liquid generated enters the atmospheric column reflux tank 5, while the tail gas is discharged through the main tail gas pipe.

[0025] Both the first atmospheric column bottom liquid pump 7 and the second atmospheric column bottom liquid pump 8 are connected to a first preheater 9 for a pressurized column and a second preheater 10 for the pressurized column. Both the first preheater 9 for the pressurized column and the second preheater 10 for the pressurized column are connected to the bottom of the pressurized column. The material in the atmospheric column 1 flows out through the discharge port, and successively enters the first atmospheric column bottom liquid pump 7 and the second atmospheric column bottom liquid pump 8 for pressurization. The pressurized material respectively enters the first preheater 9 for the pressurized column and the second preheater 10 for the pressurized column, exchanges heat with the 0.5 MPa steam condensate pipeline and the 1.0 MPa steam condensate pipeline, and finally converges and enters the bottom of the pressurized column to continue the subsequent rectification process.

[0026] The atmospheric column reflux pump 6 is respectively connected to the feed preheater and the top of the atmospheric column 1. Part of the condensate and the collected liquid in the atmospheric column reflux tank 5 are transported by the atmospheric column reflux pump 6 to the feed preheater for preheating, and the other part is refluxed to the top of the atmospheric column 1 to maintain the normal operation of the rectification process.

[0027] The tail gas outlet of the atmospheric column tail cooler 4 is connected to the main tail gas pipe.

[0028] A first feed port 12 and a second feed port 13 are provided at the lower part of the atmospheric column 1, and a discharge port is provided at the bottom of the atmospheric column 1. The raw materials are transported into the atmospheric column 1 through the first feed port 12 and the second feed port 13 of the atmospheric column 1 for rectification operation.

[0029] The preheater 1 of the pressurized column exchanges heat with the 0.5 MPa steam condensate pipeline, and the preheater 2 of the pressurized column exchanges heat with the 1.0 MPa steam condensate pipeline.

[0030] Example 2

[0031] The usage method of a waste heat recovery and utilization system for an atmospheric column in Example 1 includes the following steps:

[0032] S1. The gas-phase outlet at the top of the atmospheric column 1 enters the first circulating water heat exchanger 2 and the second circulating water heat exchanger 3, and the condensate generated by the first circulating water heat exchanger 2 and the second circulating water heat exchanger 3 enters the reflux tank 5 of the atmospheric column.

[0033] S2. The trapped liquid generated by the tail cooler 4 of the atmospheric column enters the reflux tank 5 of the atmospheric column, and the tail gas generated by the tail cooler 4 of the atmospheric column enters the main tail gas pipeline.

[0034] S3. The material of the atmospheric column 1 enters the first atmospheric column bottom liquid pump 7 and the second atmospheric column bottom liquid pump 8 through the discharge port 11 respectively for pressurization. The pressurized materials enter the first preheater 9 of the pressurized column and the second preheater 10 of the pressurized column respectively, and finally converge and enter the bottom of the pressurized column.

[0035] Therefore, by adopting the above waste heat recovery and utilization system and usage method for an atmospheric column, through reasonable structural design and process arrangement, the effective recovery and utilization of the waste heat of the atmospheric column are realized, the energy consumption in the methanol distillation process is reduced, and the energy utilization efficiency is improved.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A waste heat recovery and utilization system for an atmospheric column, characterized in that: It includes an atmospheric column. The top gas outlet of the atmospheric column is respectively connected to a first circulating water heat exchanger and a second circulating water heat exchanger. The first circulating water heat exchanger, the second circulating water heat exchanger and the tail cooler of the atmospheric column are all connected to the reflux tank of the atmospheric column. The reflux tank of the atmospheric column is connected to the reflux pump of the atmospheric column. The discharge port of the atmospheric column is successively connected to a first bottom liquid pump of the atmospheric column and a second bottom liquid pump of the atmospheric column.

2. The waste heat recovery and utilization system of an atmospheric column according to claim 1, characterized in that: Both the first bottom liquid pump of the atmospheric column and the second bottom liquid pump of the atmospheric column are connected to a first preheater of the pressurized column and a second preheater of the pressurized column. Both the first preheater of the pressurized column and the second preheater of the pressurized column are connected to the bottom of the pressurized column.

3. The waste heat recovery and utilization system of an atmospheric column according to claim 1, characterized in that: The reflux pump of the atmospheric column is respectively connected to the feed preheater and the top of the atmospheric column.

4. The waste heat recovery and utilization system of an atmospheric column according to claim 1, wherein: The tail gas outlet of the tail cooler of the atmospheric column is connected to the main tail gas pipe of the atmosphere.

5. The waste heat recovery and utilization system of an atmospheric column according to claim 1, characterized in that: The lower part of the atmospheric column is provided with a first feed port and a second feed port, and the bottom of the atmospheric column is provided with a discharge port.

6. The waste heat recovery and utilization system of an atmospheric column according to claim 2, characterized in that: The first preheater of the pressurized column exchanges heat with the 0.5 MPa steam condensate pipeline, and the second preheater of the pressurized column exchanges heat with the 1.0 MPa steam condensate pipeline.

7. A method for using the waste heat recovery and utilization system of an atmospheric column according to any one of claims 1-6, characterized in that: It includes the following steps: S1. The top gas outlet of the atmospheric column enters the first circulating water heat exchanger and the second circulating water heat exchanger, and the condensate generated by the first circulating water heat exchanger and the second circulating water heat exchanger enters the reflux tank of the atmospheric column. S2. The trapped liquid generated by the tail cooler of the atmospheric column enters the reflux tank of the atmospheric column, and the tail gas generated by the tail cooler of the atmospheric column enters the main tail gas pipe of the atmosphere. S3. The materials in the atmospheric column enter the first bottom liquid pump of the atmospheric column and the second bottom liquid pump of the atmospheric column respectively through the discharge port for pressurization. The pressurized materials enter the first preheater of the pressurized column and the second preheater of the pressurized column respectively, and finally converge and enter the bottom of the pressurized column.

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