Heat recycling device in air separation process
By recycling the heat of the air compressor and booster in the air separation process to heat the molecular sieve regeneration contaminated nitrogen, the problem of unused heat in the air separation process is solved, and energy consumption and production costs are reduced.
Patent Information
- Application Number
- CN202422070859.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In existing air separation technologies, the heat generated by air compression is not effectively utilized, resulting in excessive consumption of circulating water cooling and steam, which increases energy consumption and production costs.
The heat generated by the air compressor and booster in the air separation process is recovered through a heat recovery heat exchanger and used to heat the molecular sieve regeneration contaminated nitrogen, reducing the circulating water cooling capacity and steam consumption.
It reduces energy consumption in the air separation process, reduces the consumption of circulating water cooling capacity and steam, and reduces the production cost of the enterprise.
Smart Images
Figure CN223400215U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of air separation, in particular to a heat recovery and utilization device in an air separation process. Background Art
[0002] With the rise of my country's coal chemical, petrochemical, and nonferrous metallurgical industries, new demands have been placed on air separation technology. Safety, reliability, energy conservation, and emission reduction are fundamental requirements and prerequisites for air separation technology, essential for building a resource-saving, environmentally friendly society, and for scientific development. Existing air separation technologies require air compressors or boosters to pressurize air before separating oxygen, nitrogen, and argon from it. Air compression is a multi-stage, constant-temperature compression process that requires a large amount of circulating water to cool the air. This effectively degrades the heat generated by air compression and instead increases circulating water cooling capacity. Furthermore, molecular sieves, used to purify air in the air separation process, require regeneration after purification to remove impurities such as water, carbon dioxide, acetylene, and hydrocarbons adsorbed by the molecular sieve. In existing air separation processes, molecular sieve regeneration is performed by heating the contaminated nitrogen generated during the air separation process to above 170°C, which consumes a large amount of steam. Utility Model Content
[0003] Based on the existing technical problems, the utility model provides a heat recovery and utilization device in the air separation process. The utility model recovers the heat generated by the air compressor or booster in the air separation process to heat the contaminated nitrogen gas for molecular sieve regeneration, thereby reducing the consumption of circulating water cooling capacity for cooling air and the amount of steam used for heating the contaminated nitrogen gas, effectively reducing the energy consumption in the air separation process and reducing the production cost of the enterprise.
[0004] In order to solve the above technical problems, the technical solutions of the present invention are as follows:
[0005] A heat recovery and utilization device in an air separation process comprises an air separation tower, wherein the air separation tower is provided with an upper tower and a lower tower. The contaminated nitrogen outlet of the upper tower is connected to a plate heat exchanger via a pipeline. The contaminated nitrogen outlet of the plate heat exchanger is divided into two paths via a pipeline, one path is connected to a heat recovery heat exchanger a via a pipeline, and the other path is connected to a heat recovery heat exchanger b via a pipeline. The contaminated nitrogen outlets of the heat recovery heat exchanger a and the heat recovery heat exchanger b are both connected to a steam heater via a pipeline, and the contaminated nitrogen outlet of the steam heater is connected to a molecular sieve device via a pipeline; the air inlet of the heat recovery heat exchanger a is connected to an air compressor via a pipeline, and the air outlet of the heat recovery heat exchanger a is connected to an air cooling tower via a pipeline; the air inlet of the heat recovery heat exchanger b is connected to the air outlet of an air booster via a pipeline, and the air outlet of the heat recovery heat exchanger b is connected to the bottom of the lower tower via a pipeline.
[0006] Furthermore, the plate heat exchanger is provided with a high-pressure plate heat exchanger and a low-pressure plate heat exchanger.
[0007] Furthermore, a circulating water cooler is also provided on the pipeline connecting the air outlet of the heat recovery heat exchanger a and the air cooling tower.
[0008] Furthermore, a circulating water cooler is provided on the air outlet pipe of the heat recovery heat exchanger b.
[0009] Furthermore, one or more air compressors are provided and connected in parallel, and multiple air boosters are provided and connected in series, and the air outlet of each air booster is provided with a heat recovery heat exchanger b and a circulating water cooler in sequence. Beneficial effects
[0010] The utility model reheats the polluted nitrogen gas at the top of the air separation tower to 10°C~35°C through a plate heat exchanger and then enters a heat recovery heat exchanger a and a heat recovery heat exchanger b, and respectively exchanges heat with the air of 70°C~100°C compressed by an air compressor and an air booster. The polluted nitrogen gas exchanged with heat by the heat recovery heat exchanger a and the heat recovery heat exchanger b then enters a steam heater to be heated by steam. The polluted nitrogen gas heated by the steam heater enters a molecular sieve device. The utility model recovers part of the heat generated by the air booster and the air compressor, thereby reducing the consumption of circulating water cooling capacity by the air compressor device and the air booster device, and also reduces the consumption of steam by the steam heater. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a structural diagram of the utility model;
[0012] In the figure: 1-upper tower; 2-lower tower; 3-high-pressure plate heat exchanger; 4-low-pressure plate heat exchanger; 5-heat recovery heat exchanger a; 6-heat recovery heat exchanger b; 7-steam heater; 8-molecular sieve device; 9-air compressor; 10-air booster; 11-air cooling tower. DETAILED DESCRIPTION Example 1
[0013] Reference Figure 1 In order to recover the heat of the air separation device and reduce the energy consumption of the air separation device, thereby reducing the production cost of the enterprise, the utility model provides a heat recovery and utilization device in the air separation process, including an air separation tower, the air separation tower is provided with an upper tower 1 and a lower tower 2, the dirty nitrogen outlet of the upper tower 1 is connected to a plate heat exchanger through a pipeline, the plate heat exchanger is provided with a high-pressure plate heat exchanger 3 and a low-pressure plate heat exchanger 4, the high-pressure plate heat exchanger 3 is used for heat exchange with a medium with a higher pressure in the air separation device, and the low-pressure plate heat exchanger 4 is used for heat exchange with a medium with a lower pressure in the air separation device; the dirty nitrogen outlet of the plate heat exchanger is divided into two paths through a pipeline, one path is connected to a heat recovery heat exchanger a5 through a pipeline, and the other path is connected to a heat recovery heat exchanger b6 through a pipeline, and the heat recovery The dirty nitrogen outlet of the heat recovery heat exchanger a5 and the dirty nitrogen outlet of the heat recovery heat exchanger b6 are both connected to the steam heater 7 through a pipe, and the dirty nitrogen outlet of the steam heater 7 is connected to the molecular sieve device 8 through a pipe; a circulating water cooler is also provided on the pipe connecting the air outlet of the heat recovery heat exchanger a5 and the air cooling tower 11; a circulating water cooler is also provided on the air outlet pipe of the heat recovery heat exchanger b6; the air inlet of the heat recovery heat exchanger a5 is connected to the air compressor 9 through a pipe, and the air outlet of the heat recovery heat exchanger a5 is connected to the air cooling tower 11 through a pipe; the air inlet of the heat recovery heat exchanger b6 is connected to the air outlet of the air booster 10 through a pipe, and the air outlet of the heat recovery heat exchanger b6 is connected to the bottom of the lower tower 2 through a pipe.
[0014] One air compressor 9 is provided, and two air boosters 10 are provided and connected in series. A heat recovery heat exchanger b6 is provided at the air outlet of each air booster 10 .
[0015] Another embodiment differs from embodiment 1 in that: three air compressors 9 are provided, the three air compressors 9 are connected in parallel, and a heat recovery heat exchanger a5 and a circulating water cooler connected in sequence are respectively provided on the pipeline connecting the air outlet of each air compressor 9 and the air cooling tower 11; three air boosters 10 are provided and connected in series, and the air outlet of each air booster 10 is provided with a heat recovery heat exchanger b6 and a circulating water cooler connected in sequence.
[0016] Another embodiment differs from embodiment 1 in that: five air compressors 9 are provided, the five air compressors 9 are connected in parallel, and a heat recovery heat exchanger a5 and a circulating water cooler connected in sequence are respectively provided on the pipeline connecting the air outlet of each air compressor 9 and the air cooling tower 11; five air boosters 10 are provided and connected in series, and the air outlet of each air booster 10 is provided with a heat recovery heat exchanger b6 and a circulating water cooler connected in sequence.
[0017] Another embodiment differs from embodiment 1 in that: three air compressors 9 are provided, the three air compressors 9 are connected in parallel, the air outlets of the three air compressors 9 are merged into one through a pipeline and then connected in sequence to the heat recovery heat exchanger a5 and the circulating water cooler; three air boosters 10 are provided and connected in series, and the air outlet of each air booster 10 is provided with a heat recovery heat exchanger b6 and a circulating water cooler connected in sequence.
[0018] The working principle of the utility model is as follows: the utility model reheats the dirty nitrogen gas at the top of the upper tower 1 of the air separation tower to 10℃~35℃ through a plate heat exchanger, and then enters the heat recovery heat exchanger a5 and the heat recovery heat exchanger b6, and exchanges heat with the 70℃~100℃ air compressed by the air compressor 9 and the air booster 10 respectively. The dirty nitrogen gas exchanged with heat by the heat recovery heat exchanger a5 and the heat recovery heat exchanger b6 then enters the steam heater 7 to be heated by steam. The dirty nitrogen gas heated by the steam heater 7 enters the molecular sieve device 8 to regenerate the molecular sieve device 8; the utility model recovers part of the heat generated by the air booster 10 and the air compressor 9, thereby reducing the consumption of circulating water cooling capacity by the air compressor 9 device and the air booster 10 device, and also reduces the consumption of steam by the steam heater 7.
[0019] Modifications and changes to the invention made by those familiar with the present invention are all within the patent scope of the present invention, and are not limited to those described in the embodiments.
Claims
1. A heat recovery and utilization device in an air separation process, comprising an air separation tower, wherein the air separation tower is provided with an upper tower and a lower tower, and is characterized in that: The dirty nitrogen gas outlet of the upper tower is connected to a plate heat exchanger through a pipeline, and the dirty nitrogen gas outlet of the plate heat exchanger is divided into two routes through a pipeline, one route is connected to the heat recovery heat exchanger a through a pipeline, and the other route is connected to the heat recovery heat exchanger b through a pipeline, the dirty nitrogen gas outlet of the heat recovery heat exchanger a and the dirty nitrogen gas outlet of the heat recovery heat exchanger b are both connected to the steam heater through a pipeline, and the dirty nitrogen gas outlet of the steam heater is connected to the molecular sieve device through a pipeline; the air inlet of the heat recovery heat exchanger a is connected to the air compressor through a pipeline, and the air outlet of the heat recovery heat exchanger a is connected to the air cooling tower through a pipeline; the air inlet of the heat recovery heat exchanger b is connected to the air outlet of the air booster through a pipeline, and the air outlet of the heat recovery heat exchanger b is connected to the bottom of the lower tower through a pipeline.
2. The heat recovery and utilization device in an air separation process according to claim 1, characterized in that: The plate heat exchanger is provided with a high-pressure plate heat exchanger and a low-pressure plate heat exchanger.
3. The heat recovery and utilization device in an air separation process according to claim 1, characterized in that: A circulating water cooler is also provided on the pipeline connecting the air outlet of the heat recovery heat exchanger a and the air cooling tower.
4. The heat recovery and utilization device in an air separation process according to claim 1, characterized in that: A circulating water cooler is also provided on the air outlet pipe of the heat recovery heat exchanger b.
5. The heat recovery and utilization device in an air separation process according to any one of claims 1 to 4, characterized in that: The air compressors are arranged in one or more units and connected in parallel, the air boosters are arranged in multiple units and connected in series, and the air outlet of each air booster is sequentially provided with a heat recovery heat exchanger b and a circulating water cooler.