High-purity oxygen preparation equipment and air separation system applying same

Abstract

The invention relates to high-purity oxygen preparation equipment and an air separation system applying the high-purity oxygen preparation equipment. The high-purity oxygen preparation equipment comprises a high-purity oxygen tower and a high-purity oxygen tower evaporator, a high-purity nitrogen outlet in the top of the lower rectification tower is connected with a first gas inlet in the condensation side of the high-purity oxygen tower evaporator, and a first liquid outlet in the condensation side of the high-purity oxygen tower evaporator is connected with a reflux inlet in the top of the upper rectification tower; an oxygen-enriched gas outlet in the lower part of the lower rectifying tower is connected with a second gas inlet of a high-purity oxygen tower evaporator, and a second liquid outlet of the high-purity oxygen tower evaporator is connected with a reflux liquid inlet in the top of the high-purity oxygen tower or is connected with a reflux liquid inlet in the lower part of the upper rectifying tower; and an oxygen-enriched liquid outlet at the lower part of the upper rectifying tower is connected with a reflux liquid inlet at the top of the high-purity oxygen tower. The air separation system comprises double-tower nitrogen preparation equipment and the high-purity oxygen preparation equipment. High-purity oxygen or high-purity liquid oxygen products can be prepared on the basis of preparing high-purity nitrogen, the air separation efficiency is improved, and gas waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of air separation nitrogen production and oxygen production, and in particular to a high-purity oxygen production device based on a double-tower nitrogen production device and an air separation system using the same. Background Art

[0002] The common technology for producing nitrogen by air separation is to use double-tower nitrogen production equipment, that is, to set up two distillation towers to perform secondary distillation of air to obtain high-purity nitrogen products. This process does not have a high-purity oxygen production part, there is a certain amount of gas waste, and it is difficult to meet market demand. Conventional large-scale air separation equipment with liquid high-purity oxygen equipment is limited by regional and transportation conditions. Conventional high-purity oxygen production equipment using industrial oxygen or industrial liquid oxygen has large investment and high energy consumption, which is difficult to meet user needs. Summary of the invention

[0003] The purpose of the present invention is to provide a high-purity oxygen production device and an air separation system using the high-purity oxygen production device, which can increase the production of high-purity oxygen on the basis of air separation nitrogen production, thereby reducing gas waste and increasing the variety of primary air separation products.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: A high-purity oxygen production device operates in coordination with a double-tower nitrogen production device, the double-tower nitrogen production device comprises a lower distillation tower and an upper distillation tower, the high-purity oxygen production device comprises a high-purity oxygen tower, a high-purity oxygen tower evaporator arranged at the bottom of the high-purity oxygen tower, the bottom of the high-purity oxygen tower has a bottom liquid oxygen outlet for outputting high-purity liquid oxygen, and the condensation side of the high-purity oxygen tower evaporator has a first gas inlet, a first liquid outlet, a second gas inlet and a second liquid outlet arranged correspondingly; The high-purity nitrogen outlet at the top of the lower distillation tower is connected to the first gas inlet on the condensation side of the high-purity oxygen tower evaporator, the first liquid outlet on the condensation side of the high-purity oxygen tower evaporator is connected to the reflux liquid inlet at the top of the upper distillation tower, the oxygen-rich gas outlet at the bottom of the lower distillation tower is connected to the second gas inlet of the high-purity oxygen tower evaporator, the second liquid outlet of the high-purity oxygen tower evaporator is connected to the reflux liquid inlet at the top of the high-purity oxygen tower or to the reflux liquid inlet at the bottom of the upper distillation tower, and the oxygen-rich liquid outlet at the bottom of the upper distillation tower is connected to the reflux liquid inlet at the top of the high-purity oxygen tower.

[0005] The bottom liquid oxygen outlet is provided with a high-purity oxygen analyzer for detecting components of the output high-purity liquid oxygen and obtaining detection results.

[0006] The oxygen-rich gas outlet of the lower distillation tower is provided with a first flow controller for regulating the flow rate of the oxygen-rich gas based on the detection result of the high-purity oxygen analyzer, and the high-purity nitrogen outlet of the lower distillation tower is provided with a second flow controller for regulating the flow rate of the high-purity nitrogen based on the detection result of the high-purity oxygen analyzer.

[0007] An air separation system, comprising a double-tower nitrogen production device, and also comprising the aforementioned high-purity oxygen production device; The double-tower nitrogen production equipment comprises a compression cooling system, a precooling and purification system, a lower distillation tower, an upper distillation tower, a lower tower condenser arranged at the top of the lower distillation tower, an upper tower condenser arranged at the top of the upper distillation tower, a main heat exchanger, a first subcooler, and a second subcooler; an air source is connected to the inlet of the compression cooling system, an outlet of the compression cooling system is connected to the inlet of the precooling and purification system, an outlet of the precooling and purification system is connected to the inlet of the first heat exchange pipeline in the main heat exchanger, and the main heat exchanger is connected to the first heat exchange pipeline in the main heat exchanger. The outlet of the first heat exchange pipeline in the main heat exchanger is connected to the raw material inlet of the lower distillation tower, the high-purity nitrogen outlet at the top of the lower distillation tower is respectively connected to the gas inlet of the lower tower condenser and the inlet of the second heat exchange pipeline in the main heat exchanger, the outlet of the second heat exchange pipeline in the main heat exchanger is connected to the high-purity nitrogen product output end, the liquid outlet of the lower tower condenser is connected to a reflux liquid inlet of the lower distillation tower, and the oxygen-enriched liquid air outlet at the bottom of the lower distillation tower is connected to the outlet of the second subcooler. The inlet of the first heat exchange pipeline is connected to the lower tower condenser, the outlet of the first heat exchange pipeline in the second subcooler is connected to the liquid inlet of the lower tower condenser, the gas outlet of the lower tower condenser is connected to the raw material inlet of the upper distillation tower, the pure nitrogen outlet at the top of the upper distillation tower is connected to the gas inlet of the upper tower condenser, the liquid outlet of the upper tower condenser is respectively connected to another reflux liquid inlet at the top of the upper distillation tower and another reflux liquid inlet of the lower distillation tower, the oxygen-rich liquid outlet at the bottom of the upper distillation tower is connected to the inlet of the first heat exchange pipeline in the first subcooler, the outlet of the first heat exchange pipeline in the first subcooler is connected to the liquid inlet of the upper tower condenser, the gas outlet of the upper tower condenser is connected to the inlet of the second heat exchange pipeline in the first subcooler, the outlet of the second heat exchange pipeline in the first subcooler is connected to the inlet of the second heat exchange pipeline in the second subcooler, and the outlet of the second heat exchange pipeline in the second subcooler is connected to the oxygen-rich gas discharge end.

[0008] The outlet of the first heat exchange pipeline in the first subcooler is also connected to the inlet of the third heat exchange pipeline in the first subcooler, and the outlet of the third heat exchange pipeline in the first subcooler is connected to another liquid inlet of the lower tower condenser.

[0009] The lower liquid oxygen outlet at the lower part of the high-purity oxygen tower is connected to the inlet of the liquid oxygen pump, the outlet of the liquid oxygen pump is connected to the inlet of the third heat exchange pipeline in the main heat exchanger, and the outlet of the third heat exchange pipeline in the main heat exchanger is connected to the high-purity oxygen product output end.

[0010] The air separation system also includes a booster turbine expander, the outlet of the second heat exchange pipeline in the second subcooler is connected to the inlet of the fourth heat exchange pipeline in the main heat exchanger, the outlet of the fourth heat exchange pipeline in the main heat exchanger is connected to the inlet of the expansion end of the booster turbine expander, the outlet of the expansion end of the booster turbine expander is connected to the inlet of the fifth heat exchange pipeline in the main heat exchanger, and the outlet of the fifth heat exchange pipeline in the main heat exchanger is connected to the oxygen-rich gas discharge end.

[0011] The fifth heat exchange pipeline in the main heat exchanger branches out into a branch pipeline, and the branch pipeline is connected to the inlet of the expansion end of the booster turbine expander.

[0012] The oxygen-rich gas outlet at the top of the high-purity oxygen tower is connected to the liquid inlet of the upper tower condenser or to the inlet of the sixth heat exchange pipeline in the main heat exchanger, and the outlet of the sixth heat exchange pipeline in the main heat exchanger is connected to the oxygen-rich gas discharge end.

[0013] Due to the application of the above technical scheme, the present invention has the following advantages compared with the prior art: the present invention can produce high-purity oxygen or high-purity liquid oxygen products on the basis of producing high-purity nitrogen, thereby improving air separation efficiency, reducing gas waste, and increasing the types of air separation products. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 This is a schematic diagram of an air separation system according to Embodiment 1 of the present invention.

[0015] Attached Figure 2 This is a schematic diagram of an air separation system according to Embodiment 2 of the present invention.

[0016] Attached Figure 3 This is a schematic diagram of an air separation system according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0018] Embodiment 1: As shown in the attached Figure 1 As shown, an air separation system includes a double-tower nitrogen production equipment and a high-purity oxygen production equipment that operate in coordination.

[0019] The double-tower nitrogen production equipment includes a compression cooling system, a precooling purification system, a distillation lower tower C1, a distillation upper tower C2, a lower tower condenser K1 arranged at the top of the distillation lower tower C1, an upper tower condenser K2 arranged at the top of the distillation upper tower C2, a main heat exchanger E1, a first subcooler E2, and a second subcooler E3.

[0020] The lower distillation tower C1 has the following ports: raw material inlet, two reflux liquid inlets at the top, high-purity nitrogen outlet at the top, oxygen liquid air outlet at the bottom, and oxygen-enriched gas outlet at the bottom. The upper distillation tower C2 has the following ports: raw material inlet, two reflux liquid inlets at the top, pure nitrogen outlet at the top, and oxygen-enriched liquid outlet at the bottom. The lower tower condenser K1 has the following ports: gas inlet and liquid outlet on the condensation side, liquid inlet and gas outlet on the evaporation side. The upper tower condenser K2 has the following ports: gas inlet and liquid outlet on the condensation side, liquid inlet and gas outlet on the evaporation side. The main heat exchanger E1, the first subcooler E2, and the second subcooler E3 each have multiple heat exchange pipelines, which are numbered to distinguish these heat exchange pipelines, and the numbering order does not represent their arrangement order.

[0021] An air source for providing air is connected to the inlet of the compression and cooling system, the outlet of the compression and cooling system is connected to the inlet of the precooling and purification system, the outlet of the precooling and purification system is connected to the inlet of the first heat exchange pipeline in the main heat exchanger E1, the outlet of the first heat exchange pipeline in the main heat exchanger E1 is connected to the raw material inlet of the lower distillation tower C1, the high-purity nitrogen outlet at the top of the lower distillation tower C1 is divided into three routes, two of which are respectively connected to the gas inlet of the lower tower condenser K1 and the inlet of the second heat exchange pipeline in the main heat exchanger E1, the outlet of the second heat exchange pipeline in the main heat exchanger E1 is connected to the high-purity nitrogen product output end, the liquid outlet of the lower tower condenser K1 is connected to a reflux liquid inlet of the lower distillation tower C1, the oxygen-rich liquid air outlet at the bottom of the lower distillation tower C1 is connected to the inlet of the first heat exchange pipeline in the second subcooler E3, and the outlet of the first heat exchange pipeline in the second subcooler E3 is connected to the lower tower condenser K1 through a throttle valve LV1. The liquid inlet of the lower tower condenser K1 is connected, the gas outlet of the lower tower condenser K1 is connected to the raw material inlet of the upper distillation tower C2, the pure nitrogen outlet at the top of the upper distillation tower C2 is connected to the gas inlet of the upper tower condenser K2, the liquid outlet of the upper tower condenser K2 is respectively connected to another reflux liquid inlet at the top of the upper distillation tower C2 and to another reflux liquid inlet of the lower distillation tower C1 through the liquid nitrogen pump NP601, the oxygen-rich liquid outlet at the bottom of the upper distillation tower C2 is connected to the inlet of the first heat exchange pipeline in the first supercooler E2, the outlet of the first heat exchange pipeline in the first supercooler E2 is connected to the liquid inlet of the upper tower condenser K2, the gas outlet of the upper tower condenser K2 is connected to the inlet of the second heat exchange pipeline in the first supercooler E2, the outlet of the second heat exchange pipeline in the first supercooler E2 is connected to the inlet of the second heat exchange pipeline in the second supercooler E3, and the outlet of the second heat exchange pipeline in the second supercooler E3 is connected to the oxygen-rich oxygen discharge end. The outlet of the first heat exchange pipeline in the first subcooler E2 also branches out into another route and is connected to the inlet of the third heat exchange pipeline in the first subcooler E2 through the throttle valve LV2. The outlet of the third heat exchange pipeline in the first subcooler E2 is connected to another liquid inlet of the lower tower condenser K1.

[0022] The high-purity oxygen production equipment is connected to the double-tower nitrogen production equipment, and includes a high-purity oxygen tower C3 and a high-purity oxygen tower evaporator K3 arranged at the bottom of the high-purity oxygen tower C3. The high-purity oxygen tower C3 has the following ports: two reflux liquid inlets at the top, a bottom liquid oxygen outlet at the bottom for outputting high-purity liquid oxygen, a lower liquid oxygen outlet at the bottom for outputting liquid oxygen, and an oxygen-enriched gas outlet at the top. The high-purity oxygen tower evaporator K3 has the following ports: a first gas inlet and a first liquid outlet corresponding to the condensation side, and a second gas inlet and a second liquid outlet corresponding to the condensation side.

[0023] The third path branched off from the high-purity nitrogen outlet at the top of the lower distillation tower C1 is connected to the first gas inlet on the condensation side of the high-purity oxygen tower evaporator K3, the first liquid outlet on the condensation side of the high-purity oxygen tower evaporator K3 is connected to the reflux liquid inlet at the top of the upper distillation tower C2 via the throttle valve HV3, the oxygen-rich gas outlet at the lower part of the lower distillation tower C1 is connected to the second gas inlet of the high-purity oxygen tower evaporator K3, the second liquid outlet of the high-purity oxygen tower evaporator K3 is connected to the reflux liquid inlet at the top of the high-purity oxygen tower C3 via the throttle valve HV1, the oxygen-rich liquid outlet at the lower part of the upper distillation tower C2 is connected to the inlet of the fourth heat exchange pipeline in the first subcooler E2, and the outlet of the fourth heat exchange pipeline in the first subcooler E2 is connected to the reflux liquid inlet at the top of the high-purity oxygen tower C3 via the throttle valve HV2. The lower liquid oxygen outlet at the bottom of the high-purity oxygen tower C3 is connected to the inlet of the liquid oxygen pump OP701, and the outlet of the liquid oxygen pump OP701 is connected to the inlet of the third heat exchange pipeline in the main heat exchanger E1, and the outlet of the third heat exchange pipeline in the main heat exchanger E1 is connected to the high-purity oxygen product output end. The liquid oxygen pump OP701 is used to increase the pressure of the high-purity liquid oxygen so that it can effectively exchange heat with other media in the main heat exchanger E1, thereby achieving the conversion of high-purity liquid oxygen to high-purity oxygen products. The oxygen-enriched gas outlet at the top of the high-purity oxygen tower C3 is connected to the liquid inlet of the upper tower condenser K2. The oxygen-enriched gas outlet at the top of the high-purity oxygen tower C3 is connected to the liquid inlet of the upper tower condenser K2.

[0024] The air separation system also includes a booster turbine expander ET1, the outlet of the second heat exchange pipeline in the second subcooler E3 is connected to the inlet of the fourth heat exchange pipeline in the main heat exchanger E1, the outlet of the fourth heat exchange pipeline in the main heat exchanger E1 is connected to the inlet of the expansion end of the booster turbine expander ET1, the outlet of the expansion end of the booster turbine expander ET1 is connected to the inlet of the fifth heat exchange pipeline in the main heat exchanger E1, and the outlet of the fifth heat exchange pipeline in the main heat exchanger E1 is connected to the oxygen-rich gas discharge end. The booster turbine expander ET1 is used to generate cold through expansion work, provide an additional cold source for the entire air separation system, and improve the refrigeration efficiency of the system. The fifth heat exchange pipeline in the main heat exchanger E1 branches out a branch pipeline, and the branch pipeline is connected to the inlet of the expansion end of the booster turbine expander ET1. The branch pipeline is used to adjust the gas flow and pressure entering the expansion end of the booster turbine expander ET1, optimize the working performance of the booster turbine expander ET1, and further improve the refrigeration effect of the system.

[0025] The process flow of the above air separation system is as follows: the air is compressed, cooled, purified by cooling, and then sent to the main heat exchanger E1. In the main heat exchanger E1, the air exchanges heat with the refluxed oxygen-rich gas, product nitrogen, and product high-purity oxygen. The air is cooled to about the saturation temperature and enters the bottom of the lower distillation tower C1. High-purity nitrogen is obtained at the top of the lower distillation tower C1. Part of the high-purity nitrogen is extracted and reheated in the main heat exchanger E1 and sent out as product nitrogen. Oxygen-rich liquid air is obtained at the bottom of the lower distillation tower C1. After being supercooled by the second supercooler E3, it enters the lower tower condenser K1 through the throttle valve LV1. The evaporated oxygen-rich gas enters the upper distillation tower C2 for distillation. Pure nitrogen is obtained at the top of the upper distillation tower C2. The pure nitrogen out of the upper distillation tower C2 enters the upper tower condenser K2 and is condensed into liquid nitrogen. Part of it returns to the upper distillation tower C2 as reflux liquid to participate in distillation, and part of it is pressurized by the liquid nitrogen pump NP601 and sent to the top of the lower distillation tower C1 as reflux liquid to participate in distillation. A stream of nitrogen is extracted from the top of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, where it is condensed into liquid nitrogen. The liquid nitrogen is sent to the upper distillation tower C2 as reflux liquid to participate in distillation after passing through the throttle valve HV3. At the same time, it also provides another part of the heat source to the high-purity oxygen tower evaporator K3, so that the liquid oxygen on the evaporation side is vaporized to form the rising gas of the high-purity oxygen tower C3. A stream of oxygen-rich gas is extracted from the lower part of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, where it is condensed into liquid oxygen-rich gas. At the same time, it also provides a part of the heat source to the high-purity oxygen tower evaporator K3, so that the liquid oxygen on the evaporation side is vaporized to form the rising gas of the high-purity oxygen tower C3. The liquid oxygen-rich gas is sent to the top of the high-purity oxygen tower C3 after passing through the throttle valve HV1. Another stream of oxygen-rich liquid is extracted from the lower part of the upper distillation tower C2, and after being supercooled by the first subcooler E2 and passing through the throttle valve HV2, it is also sent to the top of the high-purity oxygen tower C3. In the high-purity oxygen tower C3, the reflux liquid exchanges heat and mass with the rising gas, and a high-purity liquid oxygen product is obtained at the bottom of the high-purity oxygen tower C3. High-purity liquid oxygen is extracted from the lower part of the high-purity oxygen tower C3, pressurized by the liquid oxygen pump OP701, and then reheated to room temperature in the main heat exchanger E1 and sent out as a high-purity oxygen product. The oxygen-rich gas obtained at the top of the high-purity oxygen tower C3 is sent to the upper tower condenser K2 to provide a cold source for the upper tower condenser K2, and after evaporation in the upper tower condenser K2, it is expanded in the booster turbine expander ET1 to provide more cooling capacity for the equipment.

[0026] In the above scheme, a high-purity oxygen analyzer is also set at the bottom liquid oxygen outlet of the high-purity oxygen tower C3 for detecting the components of the output high-purity liquid oxygen and obtaining the detection results. At the same time, a first flow controller for adjusting the flow of oxygen-rich gas based on the detection results of the high-purity oxygen analyzer is set at the oxygen-rich gas outlet of the lower distillation tower C1, and a second flow controller for adjusting the flow of high-purity nitrogen based on the detection results of the high-purity oxygen analyzer is set on a branch line connecting the high-purity nitrogen outlet of the lower distillation tower C1 to the condenser of the high-purity oxygen tower C3. The high-purity oxygen analyzer is used to detect at the analysis point AE. When any component of argon and methane in the product exceeds the standard, the nitrogen flow FL2 extracted from the top of the lower distillation tower C1 and sent to the high-purity oxygen tower C3 is adjusted by the second flow controller, and the oxygen-rich gas flow FL1 extracted from the lower part of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3 is adjusted by the second flow controller, so as to adjust the impurities of the product to meet the product requirements.

[0027] Embodiment 2: As shown in the attached Figure 2 As shown, the difference between the air separation system in this embodiment and that in the first embodiment is that the oxygen-rich gas outlet at the top of the high-purity oxygen tower C3 is not connected to the liquid inlet of the upper tower condenser K2, but the oxygen-rich gas outlet at the top of the high-purity oxygen tower C3 is connected to the inlet of the sixth heat exchange pipeline in the main heat exchanger E1, and the outlet of the sixth heat exchange pipeline in the main heat exchanger E1 is connected to the oxygen-rich gas discharge end.

[0028] The process flow of the double-tower nitrogen production equipment of the air separation system of this embodiment is the same as that of the first embodiment, and the process flow of the high-purity oxygen production equipment is as follows: a stream of nitrogen is extracted from the top of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, condensed into liquid nitrogen in the high-purity oxygen tower evaporator K3, and the liquid nitrogen is sent to the upper distillation tower C2 as reflux liquid to participate in distillation after passing through the throttle valve HV3, and at the same time, another part of the heat source is provided to the high-purity oxygen tower evaporator K3 to vaporize the liquid oxygen on the evaporation side to form the rising gas of the high-purity oxygen tower C3. A stream of oxygen-rich gas is extracted from the lower part of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, condensed into liquid oxygen-rich gas in the high-purity oxygen tower evaporator K3, and at the same time, a part of the heat source is provided to the high-purity oxygen tower evaporator K3 to vaporize the liquid oxygen on the evaporation side to form the rising gas of the high-purity oxygen tower C3. The liquid oxygen-rich gas is sent to the top of the high-purity oxygen tower C3 after passing through the throttle valve HV1. Another stream of oxygen-rich liquid is extracted from the lower part of the upper distillation tower C2, and is also sent to the top of the high-purity oxygen tower C3 after being supercooled by the first supercooler E2 and passing through the throttle valve HV2. In the high-purity oxygen tower C3, the reflux liquid exchanges heat and mass with the rising gas, and a high-purity liquid oxygen product is obtained at the bottom of the high-purity oxygen tower C3. High-purity liquid oxygen is extracted from the lower part of the high-purity oxygen tower C3, pressurized by the liquid oxygen pump OP701, and then reheated to room temperature in the main heat exchanger E1 and sent out as a high-purity oxygen product. The oxygen-rich gas obtained at the top of the high-purity oxygen tower C3 is sent to the main heat exchanger E1 for reheating and then exits the cold box.

[0029] Embodiment 3: As shown in the attached Figure 3 As shown, the difference between the air separation system in this embodiment and that in the first embodiment is that the second liquid outlet of the high purity oxygen tower evaporator K3 is not connected to the reflux liquid inlet at the top of the high purity oxygen tower C3, but the second liquid outlet of the high purity oxygen tower evaporator K3 is connected to the reflux liquid inlet at the bottom of the distillation upper tower C2 through the throttle valve HV1.

[0030] The process flow of the double-tower nitrogen production equipment of the air separation system of this embodiment is the same as that of the first embodiment, and the process flow of the high-purity oxygen production equipment is as follows: a stream of nitrogen is extracted from the top of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, condensed into liquid nitrogen in the high-purity oxygen tower evaporator K3, and the liquid nitrogen is sent to the upper distillation tower C2 as reflux liquid to participate in distillation after passing through the throttle valve HV3, and at the same time, another part of the heat source is provided to the high-purity oxygen tower evaporator K3 to vaporize the liquid oxygen on the evaporation side to form the rising gas of the high-purity oxygen tower C3. A stream of oxygen-rich gas is extracted from the lower part of the lower distillation tower C1 and sent to the condensation side of the high-purity oxygen tower evaporator K3, condensed into liquid oxygen-rich gas in the high-purity oxygen tower evaporator K3, and at the same time, a part of the heat source is provided to the high-purity oxygen tower evaporator K3 to vaporize the liquid oxygen on the evaporation side to form the rising gas of the high-purity oxygen tower C3. The liquid oxygen-rich gas is sent to the lower part of the upper tower as reflux liquid after passing through the throttle valve HV1. Another stream of oxygen-rich liquid is extracted from the lower part of the upper distillation tower C2, and after being supercooled by the first subcooler E2 and passing through the throttle valve HV2, it is also sent to the top of the high-purity oxygen tower C3. In the high-purity oxygen tower C3, the reflux liquid exchanges heat and mass with the rising gas, and a high-purity liquid oxygen product is obtained at the bottom of the high-purity oxygen tower C3. High-purity liquid oxygen is extracted from the lower part of the high-purity oxygen tower C3, pressurized by the liquid oxygen pump OP701, and then reheated to room temperature in the main heat exchanger E1 and sent out as a high-purity oxygen product. The oxygen-rich gas obtained at the top of the high-purity oxygen tower C3 is sent to the upper tower condenser K2 to provide a cold source for the upper tower condenser K2, and after evaporation in the upper tower condenser K2, it is expanded in the booster turbine expander ET1 to provide more cooling capacity for the equipment.

[0031] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-purity oxygen production equipment, which operates in conjunction with a double-tower nitrogen production equipment, wherein the double-tower nitrogen production equipment comprises a lower distillation tower and an upper distillation tower, and is characterized in that: The high-purity oxygen production equipment comprises a high-purity oxygen tower, and a high-purity oxygen tower evaporator arranged at the bottom of the high-purity oxygen tower, wherein the bottom of the high-purity oxygen tower has a bottom liquid oxygen outlet for outputting high-purity liquid oxygen, and the condensation side of the high-purity oxygen tower evaporator has a first gas inlet, a first liquid outlet, a second gas inlet, and a second liquid outlet arranged correspondingly; The high-purity nitrogen outlet at the top of the lower distillation tower is connected to the first gas inlet on the condensation side of the high-purity oxygen tower evaporator, the first liquid outlet on the condensation side of the high-purity oxygen tower evaporator is connected to the reflux liquid inlet at the top of the upper distillation tower, the oxygen-rich gas outlet at the bottom of the lower distillation tower is connected to the second gas inlet of the high-purity oxygen tower evaporator, the second liquid outlet of the high-purity oxygen tower evaporator is connected to the reflux liquid inlet at the top of the high-purity oxygen tower or to the reflux liquid inlet at the bottom of the upper distillation tower, and the oxygen-rich liquid outlet at the bottom of the upper distillation tower is connected to the reflux liquid inlet at the top of the high-purity oxygen tower.

2. The high purity oxygen production equipment according to claim 1, characterized in that: The bottom liquid oxygen outlet is provided with a high-purity oxygen analyzer for detecting components of the output high-purity liquid oxygen and obtaining detection results.

3. The high purity oxygen production equipment according to claim 2, characterized in that: The oxygen-rich gas outlet of the lower distillation tower is provided with a first flow controller for regulating the flow rate of the oxygen-rich gas based on the detection result of the high-purity oxygen analyzer, and the high-purity nitrogen outlet of the lower distillation tower is provided with a second flow controller for regulating the flow rate of the high-purity nitrogen based on the detection result of the high-purity oxygen analyzer.

4. An air separation system, comprising a double-tower nitrogen production device, characterized in that: The air separation system further comprises a high purity oxygen production device as claimed in any one of claims 1 to 3; The double-tower nitrogen production equipment comprises a compression cooling system, a precooling and purification system, a lower distillation tower, an upper distillation tower, a lower tower condenser arranged at the top of the lower distillation tower, an upper tower condenser arranged at the top of the upper distillation tower, a main heat exchanger, a first subcooler, and a second subcooler; an air source is connected to the inlet of the compression cooling system, an outlet of the compression cooling system is connected to the inlet of the precooling and purification system, an outlet of the precooling and purification system is connected to the inlet of the first heat exchange pipeline in the main heat exchanger, and the main heat exchanger is connected to the first heat exchange pipeline in the main heat exchanger. The outlet of the first heat exchange pipeline in the main heat exchanger is connected to the raw material inlet of the lower distillation tower, the high-purity nitrogen outlet at the top of the lower distillation tower is respectively connected to the gas inlet of the lower tower condenser and the inlet of the second heat exchange pipeline in the main heat exchanger, the outlet of the second heat exchange pipeline in the main heat exchanger is connected to the high-purity nitrogen product output end, the liquid outlet of the lower tower condenser is connected to a reflux liquid inlet of the lower distillation tower, and the oxygen-enriched liquid air outlet at the bottom of the lower distillation tower is connected to the outlet of the second subcooler. The inlet of the first heat exchange pipeline is connected to the lower tower condenser, the outlet of the first heat exchange pipeline in the second subcooler is connected to the liquid inlet of the lower tower condenser, the gas outlet of the lower tower condenser is connected to the raw material inlet of the upper distillation tower, the pure nitrogen outlet at the top of the upper distillation tower is connected to the gas inlet of the upper tower condenser, the liquid outlet of the upper tower condenser is respectively connected to another reflux liquid inlet at the top of the upper distillation tower and another reflux liquid inlet of the lower distillation tower, the oxygen-rich liquid outlet at the bottom of the upper distillation tower is connected to the inlet of the first heat exchange pipeline in the first subcooler, the outlet of the first heat exchange pipeline in the first subcooler is connected to the liquid inlet of the upper tower condenser, the gas outlet of the upper tower condenser is connected to the inlet of the second heat exchange pipeline in the first subcooler, the outlet of the second heat exchange pipeline in the first subcooler is connected to the inlet of the second heat exchange pipeline in the second subcooler, and the outlet of the second heat exchange pipeline in the second subcooler is connected to the oxygen-rich gas discharge end.

5. The air separation system according to claim 4, characterized in that: The outlet of the first heat exchange pipeline in the first subcooler is also connected to the inlet of the third heat exchange pipeline in the first subcooler, and the outlet of the third heat exchange pipeline in the first subcooler is connected to another liquid inlet of the lower tower condenser.

6. The air separation system according to claim 4, characterized in that: The lower liquid oxygen outlet at the lower part of the high-purity oxygen tower is connected to the inlet of the liquid oxygen pump, the outlet of the liquid oxygen pump is connected to the inlet of the third heat exchange pipeline in the main heat exchanger, and the outlet of the third heat exchange pipeline in the main heat exchanger is connected to the high-purity oxygen product output end.

7. The air separation system according to claim 4, characterized in that: The air separation system also includes a booster turbine expander, the outlet of the second heat exchange pipeline in the second subcooler is connected to the inlet of the fourth heat exchange pipeline in the main heat exchanger, the outlet of the fourth heat exchange pipeline in the main heat exchanger is connected to the inlet of the expansion end of the booster turbine expander, the outlet of the expansion end of the booster turbine expander is connected to the inlet of the fifth heat exchange pipeline in the main heat exchanger, and the outlet of the fifth heat exchange pipeline in the main heat exchanger is connected to the oxygen-rich gas discharge end.

8. The air separation system according to claim 7, characterized in that: The fifth heat exchange pipeline in the main heat exchanger branches out into a branch pipeline, and the branch pipeline is connected to the inlet of the expansion end of the booster turbine expander.

9. The air separation system according to claim 4, characterized in that: The oxygen-rich gas outlet at the top of the high-purity oxygen tower is connected to the liquid inlet of the upper tower condenser or to the inlet of the sixth heat exchange pipeline in the main heat exchanger, and the outlet of the sixth heat exchange pipeline in the main heat exchanger is connected to the oxygen-rich gas discharge end.

Images