Feed gas supply for a cryogenic rectification system
Patent Information
- Application Number
- CN202522316738.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-10-31
AI Technical Summary
然而，空分设备的高能耗问题一直是化工行业关注的焦点
[0011]本实用新型有益效果是：首先，本实用新型将经空压机组进行第一次压缩并经第一机后换热器冷却后的压缩空气输送给主换热器的第一热源通道和持续输送给主换热器冷源换热，从而获取温度更低的压缩空气，进而降低了透平膨胀机的增压端进口侧压缩空气的温度，进而降低了透平膨胀机的增压端的负荷。并且本产品在空分系统开车阶段能够利用回流冷却气输送管输送经透平膨胀机的膨胀端降温后的一部分低温气体形成主换热器，相比正常的空分供气系统利用成品气作为主换热器的冷源，在开车阶段主换热器获取冷源等待的时间更短，从而使得主换热器的温度分布更容易达到开车状态。
Smart Images
Figure CN224815255U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of feed gas supply equipment for cryogenic distillation systems, and specifically to a feed gas supply device for cryogenic distillation systems. Background Technology
[0002] Air separation units, as indispensable key equipment in the chemical industry, play a crucial role in separating gases such as oxygen and nitrogen from the air, providing essential raw materials for chemical production processes. However, the high energy consumption of air separation units has always been a focus of attention in the chemical industry. This enormous energy consumption not only increases operating costs for enterprises but also has a significant negative impact on the environment. Developing reasonable energy-saving and consumption-reducing strategies for air separation units is of profound significance for improving production efficiency, reducing energy consumption, and protecting the ecological environment. By adopting effective energy-saving measures, enterprises can not only reduce operating costs but also actively respond to environmental protection calls and promote sustainable development.
[0003] Air separation equipment, also known as air separation unit, is primarily used to separate oxygen, nitrogen, and other gases from the air. The energy consumption of air separation equipment mainly consists of the electricity consumed by the motor-driven compressor unit and auxiliary equipment. Specifically, compressor unit energy consumption includes the energy consumption of air compressors, booster compressors, product booster pumps, and external compression oxygen and nitrogen compressors. These devices are the core of the air separation unit, and their energy consumption accounts for a large proportion of the overall energy consumption. Auxiliary equipment energy consumption includes the energy consumption of water pumps, cryogenic liquid pumps, electric heaters, various compressor oil pumps, oil tank heaters, and control systems. Although these devices have relatively lower energy consumption, they still affect the overall energy consumption of the air separation unit. For air separation units with variable loads for liquid products, multiple compressions are used to obtain higher-pressure compressed air. After heat exchange with other cold source gases through the main heat exchanger, the air expands and cools, allowing a unit volume of gas to carry more cold energy to participate in air separation distillation to obtain a predetermined amount of liquid product. Obtaining high-pressure compressed air requires multiple compressions; otherwise, excessive compression in a single operation can easily damage the compressor. In existing technology, after the compressor unit compresses the air, a heat exchanger at the compressor unit's outlet cools the compressed air before it is sent to the next stage compressor unit for further pressurization. However, as the compressed air pressure gradually increases, the pressure of the compressed air received at the compressor unit's inlet also gradually increases, leading to increased energy consumption. This is especially true for the final stage compressor unit; when the compressed air pressure increases, further pressurizing the already high-pressure compressed air will undoubtedly keep the final stage compressor unit under constant high load. This constant high load significantly increases the likelihood of equipment damage. Therefore, there is room for improvement in existing technology to reduce the load on the final stage compressor unit and lower the probability of damage. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a feed gas supply device for a cryogenic distillation system that can reduce the temperature of compressed air at the inlet side of the final stage compressor unit, thereby reducing the power of the final stage compressor unit, thus overcoming the deficiencies in existing technologies.
[0005] The technical solution adopted by this utility model is as follows: a raw material gas supply device for a low-temperature distillation system, comprising a main heat exchanger and a distillation column. The distillation column, from top to bottom, includes an upper column, a main condenser-evaporator, and a lower column. A first raw material gas supply pipe is provided on the main heat exchanger. Along the direction from the inlet end near the inlet end of the first raw material gas supply pipe to the inlet end away from the inlet end of the first raw material gas supply pipe, a second raw material gas delivery pipe inlet end, a first regulating valve, an air compressor unit, and a first downstream heat exchanger are sequentially arranged. The feed gas supply pipe is connected to the first heat source channel of the main heat exchanger. The outlet end of the first feed gas supply pipe is equipped with the booster inlet of the turbine expander. The booster outlet of the turbine expander, the main heat exchanger, and the lower tower are equipped with liquefied feed conveying pipes. The liquefied feed conveying pipe is connected to the second heat source channel of the main heat exchanger. The second heat source channel of the main heat exchanger is equipped with the inlet end of the feed gas conveying branch pipe. The outlet end of the feed gas conveying branch pipe is connected to the expansion inlet of the turbine expander. The expansion outlet of the turbine expander is connected to the upper tower.
[0006] Preferably, the liquefied feedstock delivery pipe between the pressurization end of the turboexpander and the main heat exchanger is sequentially equipped with a first flow sensor, a first pressure sensor, and a cryogenic cooler along the direction from the main heat exchanger to the main heat exchanger.
[0007] Preferably, a third feed gas delivery pipe is provided between the expansion end outlet of the turbine expander and the upper tower. The third feed gas delivery pipe is provided with a second regulating valve, the inlet end of a reflux cooling gas delivery pipe, and a second flow sensor in sequence along the direction from near to far from the upper tower. The reflux cooling gas delivery pipe is connected to the first cold source channel of the main heat exchanger. The first feed gas supply pipe between the second feed gas delivery pipe and the first regulating valve is connected to the outlet end of the reflux cooling gas delivery pipe. A third regulating valve is provided on the liquefied feed gas delivery pipe between the main heat exchanger and the lower tower. A finished oxygen delivery pipe is provided on the upper tower and the main heat exchanger. The finished oxygen delivery pipe is connected to the second cold source channel of the main heat exchanger.
[0008] Preferably, the reflux cooling gas delivery pipe between the main heat exchanger and the first raw material gas supply pipe is provided with a third flow sensor, a second pressure sensor, a second downstream heat exchanger, a circulating compressor, and a fourth regulating valve in sequence along the direction from near the first raw material gas supply pipe to far away from the first raw material gas supply pipe.
[0009] Preferably, the second raw material gas conveying pipe is equipped with a fifth regulating valve and a fourth flow sensor.
[0010] Preferably, a liquid level sensor is provided at the bottom of the lower tower.
[0011] The beneficial effects of this invention are as follows: First, this invention delivers compressed air, after its initial compression by the air compressor unit and subsequent cooling by the first heat exchanger, to the first heat source channel of the main heat exchanger and continuously supplies it to the main heat exchanger for cold source heat exchange, thereby obtaining compressed air at a lower temperature. This reduces the temperature of the compressed air at the inlet side of the turboexpander's booster end, thus reducing the load on the turboexpander's booster end. Furthermore, during the start-up phase of the air separation system, this product can utilize the return cooling gas delivery pipe to transport a portion of the low-temperature gas cooled at the expansion end of the turboexpander to form the main heat exchanger. Compared to a normal air separation gas supply system that uses finished gas as the cold source for the main heat exchanger, the waiting time for the main heat exchanger to obtain a cold source is shorter during the start-up phase, making it easier for the temperature distribution of the main heat exchanger to reach the start-up state.
[0012] Secondly, the liquefied raw material conveying pipe between the pressurization end and the main heat exchanger of the turboexpander described in this utility model is sequentially equipped with a first flow sensor, a first pressure sensor and a cryogenic cooler along the direction from near the main heat exchanger to the main heat exchanger; the installation of the first flow sensor facilitates the feedback of flow parameters, and the installation of the first pressure sensor facilitates the feedback of pressure parameters.
[0013] Furthermore, a liquid level sensor is provided at the bottom of the lower tower described in this invention, and the installation of the liquid level sensor facilitates the feedback of liquid level parameters.
[0014] This utility model has a simple structure, is easy to operate, and has a clever design, which greatly improves work efficiency and has good social and economic benefits. It is a product that is easy to promote and use. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation
[0016] like Figure 1As shown, a feed gas supply device for a low-temperature distillation system includes a main heat exchanger 1 and a distillation column. The distillation column, from top to bottom, includes an upper column 2, a main condenser-evaporator 3, and a lower column 4. A first feed gas supply pipe 5 is provided on the main heat exchanger 1. Along the direction from the inlet end near the inlet end of the first feed gas supply pipe 5 to the inlet end away from the inlet end of the first feed gas supply pipe 5, a second feed gas delivery pipe 6, a first regulating valve 7, an air compressor unit 8, and a first downstream heat exchanger 9 are sequentially arranged. The second feed gas delivery pipe 6 is connected to a third heat source channel of the main heat exchanger 1. A raw material gas supply pipe 5 is connected to the first heat source channel of the main heat exchanger 1. The outlet end of the first raw material gas supply pipe 5 is provided with the inlet of the booster end of the turbine expander 10. The outlet of the booster end of the turbine expander 10, the main heat exchanger 1, and the lower tower 4 are provided with liquefied raw material conveying pipes 11. The liquefied raw material conveying pipes 11 are connected to the second heat source channel of the main heat exchanger 1. The second heat source channel of the main heat exchanger 1 is provided with the inlet end of the raw material gas conveying branch pipe 12. The outlet end of the raw material gas conveying branch pipe 12 is connected to the expansion end inlet of the turbine expander 10. The expansion end outlet of the turbine expander 10 is connected to the upper tower 2.
[0017] The liquefied raw material conveying pipe 11 between the pressurization end of the turboexpander 10 and the main heat exchanger 1 is provided with a first flow sensor 13, a first pressure sensor 14 and a cryogenic cooler 15 in sequence along the direction from near the main heat exchanger 1 to the main heat exchanger 1; the installation of the first flow sensor 13 facilitates the feedback of flow parameters, and the installation of the first pressure sensor 14 facilitates the feedback of pressure parameters.
[0018] In order to obtain more cooling capacity from the high-pressure compressed air that has been compressed multiple times and transported through the liquefied raw material conveying pipe 11, so that the compressed air is discharged from the low-temperature end of the main heat exchanger 1 to form liquefied air, which is then transported to the lower column 4 as a distillation feedstock, a third raw material gas conveying pipe 16 is provided between the expansion end outlet of the turbine expander 10 and the upper column 2. The third raw material gas conveying pipe 16 is provided with a second regulating valve 17, the inlet end of the reflux cooling gas conveying pipe 18 and a second flow sensor 19 in sequence along the direction from near to far from the upper column 2. The reflux cooling gas conveying pipe 18 is connected to the first cold source channel of the main heat exchanger 1. The first raw material gas supply pipe 5 between the second raw material gas conveying pipe 6 and the first regulating valve 7 is connected to the outlet end of the reflux cooling gas conveying pipe 18. A third regulating valve 20 is provided on the liquefied raw material conveying pipe 11 between the main heat exchanger 1 and the lower column 4. A finished product oxygen conveying pipe 21 is provided on the upper column 2 and the main heat exchanger 1. The finished product oxygen conveying pipe 21 is connected to the second cold source channel of the main heat exchanger 1. The reflux cooling gas delivery pipe 18 between the main heat exchanger 1 and the first raw material gas supply pipe 5 is sequentially equipped with a third flow sensor 22, a second pressure sensor 23, a second downstream heat exchanger 24, a circulating compressor 25, and a fourth regulating valve 26 along the direction from near to far from the first raw material gas supply pipe 5. This causes the low-temperature compressed air discharged from the expansion end outlet of the turbine expander 10 to be divided into two parts. The first part of the low-temperature compressed air is delivered to the upper column 2 as the distillation feedstock for the upper column 2. The second part of the low-temperature compressed air is delivered through the low-temperature end of the main heat exchanger 1 to the first cold source channel of the main heat exchanger 1 and the continuously supplied heat source for countercurrent heat exchange. When the second part of the low-temperature compressed air is discharged from the high-temperature end of the main heat exchanger 1, it is pressurized by the circulating compressor 25 and then delivered to the first raw material gas supply pipe 5 between the second raw material gas delivery pipe 6 and the first regulating valve 7 to form a refrigeration cycle. Furthermore, the second raw material gas delivery pipe 6 is equipped with a fifth regulating valve 27 and a fourth flow sensor 28. The flow rate of the gas used in the refrigeration cycle is fed back by the flow rate fed back by the first flow sensor 13 through the liquefied raw material conveying pipe 11, the flow rate fed back by the second flow sensor 19 through the third raw material gas conveying pipe 16, and the flow rate fed back by the third flow sensor 22 through the return cooling gas conveying pipe 18.
[0019] A liquid level sensor 29 is installed at the bottom of the lower tower 4 to facilitate the feedback of liquid level parameters.
[0020] The usage instructions for this product are as follows: Figure 1 As shown, it includes the following steps: S1. The compressed air purified by the upstream purification system is continuously supplied to the first raw material gas supply pipe 5, which is divided into two parts, namely the first part of compressed air and the second part of compressed air. The first part of compressed air is supplied to the second raw material gas supply pipe 6, and after heat exchange with the third heat source channel of the main heat exchanger 1 from the high temperature end of the main heat exchanger 1 and the cold source continuously supplied to the main heat exchanger 1, it is discharged from the low temperature end of the main heat exchanger 1 and continues to be transported along the second raw material gas supply pipe 6, and finally delivered to the lower column 4 as the gaseous distillation raw material of the lower column 4.
[0021] The second portion of compressed air continues along the first raw material gas supply pipe 5, first undergoing a first pressurization by the air compressor unit 8. After this first pressurization, the second portion of compressed air is delivered to the heat source channel of the first heat exchanger 9 and the circulating water continuously supplied to the cold source channel of the first heat exchanger 9 for counter-current heat exchange. Then, it is delivered to the first heat source channel of the main heat exchanger 1, which is supplied from the high-temperature end of the main heat exchanger 1, and to the cold source channel of the main heat exchanger 1 for further heat exchange. Finally, it is discharged from the medium-temperature zone of the main heat exchanger 1. Then, the second portion of compressed air is delivered to the turbine expander 1. The pressurization end of 0 is pressurized a second time. The second part of the compressed air after the second pressurization is sent to the liquefied raw material conveying pipe 11 and cooled by the low temperature cooler 15. The cooled second part of the compressed air is sent from the high temperature end of the main heat exchanger 1 to the second heat source channel of the main heat exchanger 1 and then divided into two parts, namely the third part of compressed air and the fourth part of compressed air. The third part of compressed air is discharged from the low temperature end of the main heat exchanger 1 and is liquefied to form liquid air. Then it continues to move along the liquefied raw material conveying pipe 11 and is sent to the lower column 4 as the liquid distillation raw material of the lower column 4.
[0022] The fourth part of compressed air is discharged from the medium temperature zone of the main heat exchanger 1 and then sent to the expansion end of the turbine expander 10 for expansion and cooling to form cooling air. The cooling air is sent to the third raw material gas delivery pipe 16 and then divided into two parts, namely the first part of cooling air and the second part of cooling air. The first part of cooling air is sent to the upper column 2 as the gaseous distillation raw material of the upper column 2.
[0023] The second part of the cooling air is supplied to the return cooling air supply pipe 18. After heat exchange with the first cold source channel of the main heat exchanger 1 and the continuously supplied heat source, the air is discharged from the high-temperature end of the main heat exchanger 1 and continues along the return cooling air supply pipe 18. It is then supplied through the outlet end of the return cooling air supply pipe 18 to the first raw material gas supply pipe 5 between the second raw material gas supply pipe 6 and the first regulating valve 7, merging into the second part of the compressed air to form a refrigeration cycle. The finished oxygen supplied by the finished oxygen supply pipe 21 is supplied from the low-temperature end of the main heat exchanger 1 to the second cold source channel of the main heat exchanger 1 and the continuously supplied heat source. After heat exchange, it is discharged from the high-temperature end of the main heat exchanger 1 and then supplied to the user through the outlet end of the finished oxygen supply pipe 21.
[0024] In this embodiment, compressed air, after being compressed for the first time by the air compressor unit 8 and cooled by the first post-compression heat exchanger 9, is delivered to the first heat source channel of the main heat exchanger 1 and continuously supplied to the main heat exchanger 1 for cold source heat exchange, thereby obtaining compressed air at a lower temperature. This reduces the temperature of the compressed air at the inlet side of the booster end of the turbine expander 10, and thus reduces the load on the booster end of the turbine expander 10. Furthermore, during the start-up phase of the air separation system, this product can utilize the return cooling gas delivery pipe 18 to deliver a portion of the low-temperature gas cooled at the expansion end of the turbine expander 10 to form the main heat exchanger 1. Compared to the normal air separation gas supply system that uses finished gas as the cold source for the main heat exchanger 1, the waiting time for the main heat exchanger 1 to obtain a cold source is shorter during the start-up phase, making it easier for the temperature distribution of the main heat exchanger 1 to reach the start-up state.
[0025] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.
Claims
1. A feed gas supply device for a low-temperature distillation system, comprising a main heat exchanger (1) and a distillation column, wherein the distillation column comprises, from top to bottom, an upper column (2), a main condenser-evaporator (3), and a lower column (4), characterized in that: The main heat exchanger (1) is provided with a first raw material gas supply pipe (5). The first raw material gas supply pipe (5) is provided with the inlet end of a second raw material gas delivery pipe (6), a first regulating valve (7), an air compressor unit (8), and a first downstream heat exchanger (9) in sequence from the inlet end near the inlet end of the first raw material gas supply pipe (5) to the inlet end away from the inlet end of the first raw material gas supply pipe (5). The first raw material gas supply pipe (5) is connected to the first heat source channel of the main heat exchanger (1). A turbine expansion valve is provided at the outlet end of the first raw material gas supply pipe (5). The turboexpander (10) is equipped with a liquefied raw material conveying pipe (11) at the inlet of the booster end, the outlet of the turboexpander (10), the main heat exchanger (1), and the lower tower (4). The liquefied raw material conveying pipe (11) is connected to the second heat source channel of the main heat exchanger (1). The second heat source channel of the main heat exchanger (1) is equipped with the inlet of the raw material gas conveying branch pipe (12). The outlet of the raw material gas conveying branch pipe (12) is connected to the expansion end inlet of the turboexpander (10). The expansion end outlet of the turboexpander (10) is connected to the upper tower (2).
2. The feed gas supply device for the cryogenic distillation system according to claim 1, characterized in that: The liquefied raw material conveying pipe (11) between the pressurization end of the turboexpander (10) and the main heat exchanger (1) is provided with a first flow sensor (13), a first pressure sensor (14) and a cryogenic cooler (15) in sequence along the direction from the main heat exchanger (1) to the main heat exchanger (1).
3. The feed gas supply device for the cryogenic distillation system according to claim 1, characterized in that: A third raw material gas delivery pipe (16) is provided between the expansion end outlet of the turbo expander (10) and the upper tower (2). The third raw material gas delivery pipe (16) is provided with a second regulating valve (17), the inlet end of the reflux cooling gas delivery pipe (18) and a second flow sensor (19) in sequence along the direction from near the upper tower (2) to far away from the upper tower (2). The reflux cooling gas delivery pipe (18) is connected to the first cold source channel of the main heat exchanger (1). The first raw material gas supply pipe (5) between the second raw material gas delivery pipe (6) and the first regulating valve (7) is connected to the outlet end of the reflux cooling gas delivery pipe (18). A third regulating valve (20) is provided on the liquefied raw material delivery pipe (11) between the main heat exchanger (1) and the lower tower (4). A finished oxygen delivery pipe (21) is provided on the upper tower (2) and the main heat exchanger (1). The finished oxygen delivery pipe (21) is connected to the second cold source channel of the main heat exchanger (1).
4. The feed gas supply device for the cryogenic distillation system according to claim 3, characterized in that: The reflux cooling gas delivery pipe (18) between the main heat exchanger (1) and the first raw material gas supply pipe (5) is provided with a third flow sensor (22), a second pressure sensor (23), a second downstream heat exchanger (24), a circulating compressor (25) and a fourth regulating valve (26) in sequence along the direction from near the first raw material gas supply pipe (5) to far away from the first raw material gas supply pipe (5).
5. The feed gas supply device for the cryogenic distillation system according to claim 1, characterized in that: The second raw material gas conveying pipe (6) is equipped with a fifth regulating valve (27) and a fourth flow sensor (28).
6. The feed gas supply device for the cryogenic distillation system according to claim 1, characterized in that: A liquid level sensor (29) is installed at the bottom of the lower tower (4).