A device and method for extracting krypton-poor xenon or oxygen-rich by main condenser evaporator

Abstract

The invention relates to a device and method for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator. The device comprises a main distillation tower, which comprises an upper tower, a main condenser evaporator and a lower tower. The lower tower is respectively connected to the first tube pass of a low-pressure plate heat exchanger, the first tube pass of a high-pressure plate heat exchanger and an air pipeline of an expansion unit. The oxygen-rich liquid air outlet pipeline at the bottom of the lower tower is connected to the middle of the upper tower through the first tube pass of a supercooler and a gas-liquid separator. The main condenser evaporator is a parallel double-main-cooled four-layer fully immersed main condenser evaporator. The nitrogen side outlet of the parallel double-main-cooled four-layer fully immersed main condenser evaporator is respectively connected to the lower tower distillation liquid inlet of the lower tower and a liquid nitrogen storage tank. The device has the characteristics of simple structure, reasonable design, liquid oxygen liquid collection spaces are respectively arranged at the bottom of the upper tower and the bottom of the main condenser evaporator, liquid oxygen is centrally extracted from the lower part of the upper tower, and the main condenser evaporator is used for liquid oxygen dry evaporation and concentration to concentrate the krypton-depleted xenon to extract high-concentration krypton and xenon liquid oxygen.

Description

Technical Field

[0001] The invention belongs to the technical field of extracting krypton and xenon in an air separation system, and relates to a device and an extraction method for extracting krypton-poor xenon or oxygen-rich by a main condenser evaporator. Background Art

[0002] Krypton and xenon, as rare gases, are widely used in lighting, space satellites and the medical industry. The content of krypton in the air is 1.14ppm, and the content of xenon is 0.086ppm. Krypton and xenon are mainly extracted from the by-products of air separation equipment. The current krypton-depleted xenon extraction device has the defects of large-scale, complex, difficult to operate, unstable products and low purity of extracted krypton and xenon. Summary of the invention

[0003] The object of the present invention is to overcome the defects in the prior art and to provide a device and method for extracting krypton-poor xenon or oxygen-rich liquid oxygen from the main condenser evaporator with a simple structure and reasonable design, which is characterized by the full-immersion double-layer main condenser evaporator in parallel in air separation equipment, and liquid oxygen collecting spaces are respectively arranged at the bottom of the upper tower and the bottom of the main condenser evaporator. By adjusting the process operation and the different product output positions, liquid oxygen is concentrated from the lower part of the upper tower, and the main condenser evaporator is used for dry evaporation and concentration of liquid oxygen to concentrate and extract high-concentration krypton- and xenon-containing liquid oxygen.

[0004] The object of the present invention is achieved as follows: a device for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower, a main condenser evaporator and a lower tower, the lower tower being respectively connected to the air ducts passing through the first tube pass of a low-pressure plate heat exchanger, the first tube pass of a high-pressure plate heat exchanger and an expansion unit; the oxygen-rich liquid air outlet pipeline at the bottom of the lower tower is connected to the middle of the upper tower through the first tube pass of a supercooler and a gas-liquid separator; the main condenser evaporator is a parallel double main cooling four-layer fully immersed main condenser evaporator, the nitrogen outlet at the upper part of the lower tower is connected to the nitrogen side inlet of the parallel double main cooling four-layer fully immersed main condenser evaporator; the bottom of the upper tower is connected to the parallel double main cooling four-layer fully immersed main condenser evaporator The oxygen side of the main cooling four-layer fully immersed main condenser evaporator is connected; the nitrogen side outlet of the parallel double main cooling four-layer fully immersed main condenser evaporator is respectively connected to the lower tower distillation liquid inlet of the lower tower and the liquid nitrogen storage tank; the bottom liquid oxygen outlet of the upper tower and the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator are connected to the high-pressure liquid oxygen pump and the second pipe pass of the high-pressure plate heat exchanger and the downstream user device in sequence through the first tee; the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator is sequentially provided with a second tee and a first regulating valve between the first tee, and the outlet of the third end of the second tee is respectively connected to the liquid oxygen storage tank and the krypton-depleted xenon extraction device through the second pipe pass of the supercooler.

[0005] Preferably, the dirty nitrogen outlet in the upper part of the lower tower is connected to the second distillation liquid inlet of the upper tower through the third tube pass of the subcooler, and the top of the upper tower is provided with a dirty nitrogen outlet, and the dirty nitrogen outlet is connected to the water cooling system through the fourth tube pass of the subcooler and the third tube pass of the high-pressure plate heat exchanger.

[0006] Preferably, the lower tower nitrogen outlet at the upper middle part of the lower tower is connected to the pure argon evaporation system through a pipeline, and a third tee is provided on the pipeline between the lower tower nitrogen outlet and the pure argon evaporation system, and the third end of the third tee is connected to the low-pressure product nitrogen pipeline network through the second pipe pass of the low-pressure plate heat exchanger.

[0007] Preferably, an annular liquid oxygen collecting tank is provided on the tower wall at the lower part of the upper tower, a bottom liquid oxygen outlet of the upper tower is provided at the bottom of the annular liquid oxygen collecting tank, the middle part of the annular liquid oxygen collecting tank is an oxygen rising channel of the main condenser evaporator, and overflow pipes are respectively provided on the parallel dual main cooling four-layer fully immersed main condenser evaporator.

[0008] Preferably, a second regulating valve is provided between the bottom liquid oxygen outlet of the upper tower and the first three-way connection.

[0009] Preferably, a fourth tee is provided at the outlet of the second tube pass of the subcooler, a second end of the fourth tee is connected to the liquid oxygen storage tank through a third regulating valve, and a third end of the fourth tee is connected to the krypton-depleted xenon extraction device through a fourth regulating valve.

[0010] Preferably, the gas phase outlet of the gas-liquid separator is connected to the gas phase inlet of the upper tower, the liquid phase outlet of the gas-liquid separator is connected to the first distillation liquid inlet of the upper tower in the middle of the upper tower, and the setting position of the first distillation liquid inlet of the upper tower is lower than the setting position of the gas phase inlet of the upper tower.

[0011] Preferably, a fifth three-way connection is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condensing evaporator and the lower tower distillation liquid inlet of the lower tower, the second end of the fifth three-way connection is connected to the lower tower distillation liquid inlet through a fifth regulating valve, and the third end of the fifth three-way connection is connected to the liquid nitrogen storage tank through the fifth pipe pass of the subcooler and the sixth regulating valve.

[0012] A method for extracting krypton-poor xenon or oxygen-rich gas from a main condenser evaporator, the method comprising the following steps:

[0013] Step 1: The first air enters the lower tower through the low-pressure plate heat exchanger, the second air enters the lower tower through the high-pressure plate heat exchanger, and the third air enters the lower tower through the expansion unit; the pressure of the first air is: 0.4~0.5Mpa, the temperature is: 15~20℃; the pressure after passing through the low-pressure plate heat exchanger is: 0.4~0.5Mpa, the temperature is: -170~-175℃; the pressure of the second air is: 7~8Mpa, the temperature is: 25~35℃; the pressure after passing through the high-pressure plate heat exchanger is: 7~8Mpa, the temperature is: -170~-175℃; the pressure after the third air is: 4.3~4.4Mpa, the temperature is: -105~-110℃; the pressure after passing through the expansion unit is: 0.45~0.5Mpa, the temperature is: -165~-170℃;

[0014] The three air streams are rectified in the lower tower with liquid nitrogen from the rectifying liquid inlet of the lower tower. After the rectification, the bottom of the lower tower is oxygen-enriched liquid air, the middle and upper parts of the lower tower are liquid air and dirty liquid nitrogen, and the top of the lower tower is pure nitrogen and liquid nitrogen; the temperature of the liquid nitrogen is -175 to -180°C; the oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C;

[0015] Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower and the first tube pass of the subcooler and enters the gas-liquid separator for gas-liquid separation. The gas phase after gas-liquid separation enters the upper tower through the gas phase inlet of the upper tower, and the liquid phase after gas-liquid separation enters the upper tower through the first distillation liquid inlet of the upper tower as the distillation liquid of the upper tower; the temperature of the gas phase after the gas-liquid separation is: -180~-185℃;

[0016] Step 3: the dirty liquid nitrogen enters the upper tower as the upper tower distillate through the dirty liquid nitrogen outlet in the upper part of the lower tower, the third tube pass of the subcooler and the second distillate inlet of the upper tower; the temperature of the upper tower distillate is: -185~-190℃;

[0017] Step 4: The liquid oxygen in the annular liquid oxygen collecting tank at the bottom of the upper tower overflows into the parallel double main cooling four-layer fully immersed main condensing evaporator, and the parallel double main cooling four-layer fully immersed main condensing evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower to produce gaseous oxygen, and the gaseous oxygen enters the upper tower through the oxygen gas ascending channel for rectification, and the liquid phase after rectification enters the annular liquid oxygen collecting tank and the main condensing evaporator, and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator through the corresponding overflow pipe; the temperature of the gaseous oxygen is: -175~-180℃;

[0018] Step 5: The pressure at the top of the lower tower is: 0.44Mpa pure nitrogen enters through the nitrogen outlet and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower through the second end of the fifth three-way, the fifth regulating valve and the lower tower distillate inlet as the distillate of the lower tower; the temperature of the liquid nitrogen is: -175~-180℃;

[0019] Step 6: When the downstream user device needs liquid oxygen, close the second regulating valve and open the first regulating valve, so that the liquid oxygen of the parallel dual main cooling four-layer fully immersed main condenser evaporator is sent to the downstream user device through the first regulating valve, the high-pressure liquid oxygen pump and the second pipe pass of the high-pressure plate heat exchanger; the gas oxygen pressure entering the downstream user device is 7.6Mpa and the temperature is: 30℃;

[0020] Step 7: When both the downstream user device and the liquid oxygen storage tank need liquid oxygen, open the first regulating valve and the third regulating valve, close the second regulating valve and the fourth regulating valve, so that the liquid oxygen at the bottom of the upper tower is sent to the downstream user device through the first tee, the high-pressure liquid oxygen pump and the second pipe pass of the high-pressure plate heat exchanger; the liquid oxygen of the parallel dual-main cooling four-layer full-immersion main condenser evaporator enters the liquid oxygen storage tank through the outlet of the third end of the second tee, the second pipe pass of the subcooler and the third regulating valve; the gas oxygen pressure entering the downstream user device is 7.6Mpa, and the temperature is: 30°C; the temperature of the liquid oxygen entering the liquid oxygen storage tank is: -186°C;

[0021] Step 8: When the downstream user device and the krypton-depleted xenon extraction device are connected, the first regulating valve and the third regulating valve are closed, and the fourth regulating valve and the second regulating valve are opened, so that the liquid oxygen at the bottom of the upper tower is sent to the downstream user device through the first tee, the high-pressure liquid oxygen pump and the second pipe pass of the high-pressure plate heat exchanger; the liquid oxygen of the parallel dual-main cooling four-layer full-immersion main condenser evaporator enters the krypton-depleted xenon extraction device through the outlet of the third end of the second tee, the second pipe pass of the supercooler and the fourth regulating valve; the gas oxygen pressure entering the downstream user device is 7.6Mpa and the temperature is: 30°C; the krypton content in the liquid oxygen entering the krypton-depleted xenon extraction device is not less than 180ppm, and the xenon content is not less than 20ppm;

[0022] Step nine: the liquid nitrogen at the top of the lower tower in the step one can be selectively fed into the low-pressure product nitrogen pipeline network or the pure argon evaporation system as required. When it is necessary to feed the pure argon evaporation system, the liquid nitrogen directly feeds the pure argon evaporation system through the lower tower liquid nitrogen outlet at the upper middle part of the lower tower and the corresponding pipeline.

[0023] When it is necessary to enter the low-pressure product nitrogen pipeline network, liquid nitrogen enters the low-pressure product nitrogen pipeline network through the lower tower liquid nitrogen outlet at the upper middle part of the lower tower, the third end of the third tee and the second pipe pass of the low-pressure plate heat exchanger; the nitrogen pressure entering the low-pressure product nitrogen pipeline network is 0.42MPa and the temperature is: 30°C.

[0024] Preferably, another part of the liquid nitrogen in step five enters the liquid nitrogen storage tank through the third end of the fifth three-way connection, the fifth pipe pass of the subcooler and the sixth regulating valve.

[0025] According to the above scheme, a device and extraction method for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator are prepared. The present invention can separate air, extract liquid oxygen and liquid oxygen containing krypton-depleted xenon in one tower by arranging a main distillation tower and arranging an upper tower, a main condenser evaporator and a lower tower inside the main distillation tower. Furthermore, a main condenser evaporator is arranged on the basis of the upper tower and the lower tower, and a parallel double-main cooling four-layer fully immersed main condenser evaporator is used to adjust the process operation and the different product output positions. Liquid oxygen is concentrated from the lower part of the upper tower, and the main condenser evaporator liquid oxygen is concentrated by dry evaporation to concentrate the krypton-depleted xenon, thereby extracting high-concentration krypton- and xenon-containing liquid oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0027] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation of the present invention is now described with reference to the accompanying drawings, in which the same reference numerals represent the same components. In order to make the drawings concise, each figure only schematically shows the parts related to the invention, and they do not represent the actual structure of the product.

[0028] like Figure 1As shown, the present invention is a device and method for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower 1, a main condenser evaporator 2 and a lower tower 3, the lower tower 3 is respectively connected to the air ducts through the first tube pass of a low-pressure plate heat exchanger 4, the first tube pass of a high-pressure plate heat exchanger 5 and an expansion unit 6; the oxygen-rich liquid air outlet pipeline at the bottom of the lower tower 3 is connected to the middle part of the upper tower 1 through the first tube pass of a subcooler 7 and a gas-liquid separator 8; the main condenser evaporator 2 is a parallel double main cooling four-layer fully immersed main condenser evaporator, the nitrogen outlet 9 at the upper part of the lower tower 3 is connected to the nitrogen side inlet of the parallel double main cooling four-layer fully immersed main condenser evaporator; the bottom of the upper tower 1 is connected to the parallel double main cooling four-layer fully immersed The oxygen side of the parallel double-main-cooling four-layer fully immersed main condenser evaporator is connected; the nitrogen side outlet of the parallel double-main-cooling four-layer fully immersed main condenser evaporator is respectively connected to the lower tower distillation liquid inlet 10 of the lower tower 3 and the liquid nitrogen storage tank 11; the bottom liquid oxygen outlet of the upper tower 1 and the liquid oxygen outlet side of the parallel double-main-cooling four-layer fully immersed main condenser evaporator are connected to the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5 and the downstream user device 14 through the first tee 12 in sequence; the liquid oxygen outlet side of the parallel double-main-cooling four-layer fully immersed main condenser evaporator is provided with a second tee 15 and a first regulating valve 16 in sequence between the first tee 12, and the outlet of the third end of the second tee 15 is respectively connected to the liquid oxygen storage tank 17 and the krypton-depleted xenon extraction device 18 through the second pipe pass of the supercooler 7. The present invention has the characteristics of simple structure, reasonable process design and easy control. Specifically, the present invention uses a main distillation tower to perform air separation treatment on air, and separates oxygen-rich liquid air, liquid air, dirty liquid nitrogen, pure nitrogen and liquid nitrogen through the lower tower 3; further, the oxygen-rich liquid air and dirty liquid nitrogen are used as distillation liquids in the upper tower 1 for distillation to obtain liquid oxygen. At the same time, the present invention uses liquid nitrogen as a heat source in a parallel double-main cooling four-layer fully immersed main condenser evaporator to heat liquid oxygen to produce gaseous oxygen. In the above process, the main condenser evaporator 2 can achieve dry evaporation and concentration of liquid oxygen to achieve krypton-poor xenon concentration and aggregation, thereby obtaining high-concentration krypton- and xenon-containing liquid oxygen. On the basis of the above, the present invention can provide liquid oxygen to users through process flow and valve control.

[0029] Furthermore, the upper dirty nitrogen outlet of the lower tower 3 is connected to the upper tower second distillation liquid inlet 19 of the upper tower 1 through the third tube pass of the subcooler 7, and the top of the upper tower 1 is provided with a dirty nitrogen outlet 37, and the dirty nitrogen outlet 37 is connected to the water cooling system 20 through the fourth tube pass of the subcooler 7 and the third tube pass of the high-pressure plate heat exchanger 5. In the present invention, the dirty liquid nitrogen in the lower tower 3 enters the upper tower 1 and is used as a distillation liquid, and then is discharged through the dirty nitrogen outlet 37 at the top of the upper tower 1.

[0030] Furthermore, the lower tower nitrogen outlet 21 at the upper middle part of the lower tower 3 is connected to the pure argon evaporation system 22 through a pipeline, and a third tee 23 is provided on the pipeline between the lower tower nitrogen outlet 21 and the pure argon evaporation system 22, and the third end of the third tee 23 is connected to the low-pressure product nitrogen pipe network 24 through the second pipe pass of the low-pressure plate heat exchanger 4. The liquid nitrogen generated in the process of air separation of the present invention can be sold as a product or enter the pure argon evaporation system 22 as a raw material for extracting argon.

[0031] Furthermore, an annular liquid oxygen collecting tank 26 is provided on the tower wall at the lower part of the upper tower 1, and the bottom of the annular liquid oxygen collecting tank 26 is provided with a bottom liquid oxygen outlet of the upper tower 1. The middle part of the annular liquid oxygen collecting tank 26 is an oxygen rising channel of the main condenser evaporator 2, and overflow pipes 27 are respectively provided on the parallel dual main cooling four-layer fully immersed main condenser evaporator. The liquid oxygen obtained by rectification in the upper tower 1 is collected through an annular liquid oxygen collecting tank 26, and the middle part of the annular liquid oxygen collecting tank 26 is an oxygen rising channel. When the liquid oxygen in the annular liquid oxygen collecting tank 26 is excessive, it overflows through the oxygen rising channel to the main condenser evaporator 2. Liquid nitrogen is used as a heat source in the parallel dual-main-cooling four-layer fully immersed main condenser evaporator to heat the liquid oxygen to produce gaseous oxygen, and the gaseous oxygen enters the upper tower 1 through the oxygen rising channel for rectification; when the liquid oxygen in the upper layer of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator is excessive, it can enter the lower layer through the overflow pipe 27, and when the liquid oxygen in the lower layer is excessive, it can enter the bottom of the main condenser evaporator 2 through the corresponding overflow pipe 27; at the same time, the overflow pipe 27 can also be used as a channel for the rise of gaseous oxygen.

[0032] Furthermore, a second regulating valve 28 is provided between the bottom liquid oxygen outlet of the upper tower 1 and the first three-way valve 12 .

[0033] Furthermore, a fourth tee 29 is provided at the outlet of the second pipe pass of the subcooler 7 , a second end of the fourth tee 29 is connected to the liquid oxygen storage tank 17 through a third regulating valve 30 , and a third end of the fourth tee 29 is connected to the krypton-depleted xenon extraction device 18 through a fourth regulating valve 31 .

[0034] Furthermore, the gas phase outlet of the gas-liquid separator 8 is connected to the upper tower gas phase inlet 32, and the liquid phase outlet of the gas-liquid separator 8 is connected to the upper tower first distillation liquid inlet 33 in the middle of the upper tower 1, and the setting position of the upper tower first distillation liquid inlet 33 is lower than the setting position of the upper tower gas phase inlet 32.

[0035] Furthermore, a fifth tee 34 is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator and the lower tower distillation liquid inlet 10 of the lower tower 3, the second end of the fifth tee 34 is connected to the lower tower distillation liquid inlet 10 through a fifth regulating valve 35, and the third end of the fifth tee 34 is connected to the liquid nitrogen storage tank 11 through the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36.

[0036] A method for extracting krypton-poor xenon or oxygen-rich gas from a main condenser evaporator, the method comprising the following steps:

[0037] Step 1: The first air enters the lower tower 3 through the low-pressure plate heat exchanger 4, the second air enters the lower tower 3 through the high-pressure plate heat exchanger 5, and the third air enters the lower tower 3 through the expansion unit 6; the pressure of the first air is: 0.4~0.5Mpa, the temperature is: 15~20℃; the pressure after passing through the low-pressure plate heat exchanger 4 is: 0.4~0.5Mpa, the temperature is: -170~-175℃; the pressure of the second air is: 7~8Mpa, the temperature is: 25~35℃; the pressure after passing through the high-pressure plate heat exchanger 5 is: 7~8Mpa, the temperature is: -170~-175℃; the pressure after the third air is: 4.3~4.4Mpa, the temperature is: -105~-110℃; the pressure after passing through the expansion unit 6 is: 0.45~0.5Mpa, the temperature is: -165~-170℃;

[0038] The three air streams are rectified in the lower tower 3 with liquid nitrogen from the lower tower rectifying liquid inlet 10. After the rectification, the bottom of the lower tower 3 is oxygen-enriched liquid air, the middle and upper parts of the lower tower 3 are liquid air and dirty liquid nitrogen, and the top of the lower tower 3 is pure nitrogen and liquid nitrogen. The temperature of the liquid nitrogen is -175 to -180°C; the oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C.

[0039] Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower 3 and the first tube pass of the subcooler 7 and enters the gas-liquid separator 8 for gas-liquid separation. The gas phase after gas-liquid separation enters the upper tower 1 through the upper tower gas phase inlet 32, and the liquid phase after gas-liquid separation enters the upper tower 1 through the upper tower first distillation liquid inlet 33 as the upper tower distillation liquid; the gas phase temperature after the gas-liquid separation is: -180 to -185°C;

[0040] Step 3: The dirty liquid nitrogen enters the upper tower 1 through the dirty liquid nitrogen outlet in the upper part of the lower tower 3, the third tube pass of the subcooler 7 and the second distillation liquid inlet 19 of the upper tower as the upper tower distillation liquid; the temperature of the upper tower distillation liquid is: -185~-190℃;

[0041] Step 4: The liquid oxygen in the annular liquid oxygen collecting tank 26 at the bottom of the upper tower 1 overflows into the parallel double main cooling four-layer fully immersed main condenser evaporator, and the parallel double main cooling four-layer fully immersed main condenser evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower 3 to produce gaseous oxygen, and the gaseous oxygen and oxygen gas ascending channel enter the upper tower 1 for distillation, and the liquid phase after distillation enters the annular liquid oxygen collecting tank 26 and the main condenser evaporator 2, and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator through the corresponding overflow pipe 27; the temperature of the gaseous oxygen is: -175~-180℃;

[0042] Step 5: The pressure at the top of the lower tower 3 is: 0.44Mpa pure nitrogen enters through the nitrogen outlet (9 and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower 3 as the distillate of the lower tower through the second end of the fifth three-way 34, the fifth regulating valve 35 and the lower tower distillate inlet 10; the temperature of the liquid nitrogen is: -175~-180℃;

[0043] Step 6: When the downstream user device 14 needs liquid oxygen, close the second regulating valve 28, open the first regulating valve 16, and send the liquid oxygen from the parallel dual main cooling four-layer fully immersed main condenser evaporator into the downstream user device 14 through the first regulating valve 16, the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa and the temperature is: 30°C;

[0044] Step 7: When both the downstream user device 14 and the liquid oxygen storage tank 17 need liquid oxygen, open the first regulating valve 16 and the third regulating valve 30, close the second regulating valve 28 and the fourth regulating valve 31, so that the liquid oxygen at the bottom of the upper tower 1 is sent to the downstream user device 14 through the first tee 12, the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5; the liquid oxygen of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator enters the liquid oxygen storage tank 17 through the outlet of the third end of the second tee 15, the second pipe pass of the subcooler 7 and the third regulating valve 30; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa, and the temperature is: 30°C; the liquid oxygen temperature entering the liquid oxygen storage tank 17 is: -186°C;

[0045] Step 8: When the downstream user device 14 and the krypton-depleted xenon extraction device 18 are connected, the first regulating valve 16 and the third regulating valve 30 are closed, and the fourth regulating valve 31 and the second regulating valve 28 are opened, so that the liquid oxygen at the bottom of the upper tower 1 is sent to the downstream user device 14 through the first tee 12, the high-pressure liquid oxygen pump 13 and the second pipe side of the high-pressure plate heat exchanger 5; the liquid oxygen of the parallel dual-main cooling four-layer full-immersion main condenser evaporator enters the krypton-depleted xenon extraction device 18 through the outlet of the third end of the second tee 15, the second pipe side of the subcooler 7 and the fourth regulating valve 31; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa, and the temperature is: 30°C; the krypton content in the liquid oxygen entering the krypton-depleted xenon extraction device 18 is not less than 180ppm, and the xenon content is not less than 20ppm;

[0046] Step nine: the liquid nitrogen at the top of the lower tower 3 in the step one can be selectively fed into the low-pressure product nitrogen pipe network 24 or the pure argon evaporation system 22 as required. When it is necessary to feed the pure argon evaporation system 22, the liquid nitrogen directly feeds the pure argon evaporation system 22 through the lower tower liquid nitrogen outlet 21 at the upper middle portion of the lower tower 3 and the corresponding pipeline.

[0047] When it is necessary to enter the low-pressure product nitrogen pipeline network 24, the liquid nitrogen enters the low-pressure product nitrogen pipeline network 24 through the lower tower liquid nitrogen outlet 21 in the upper part of the lower tower 3, the third end of the third tee 23 and the second pipe pass of the low-pressure plate heat exchanger 4; the nitrogen pressure entering the low-pressure product nitrogen pipeline network 24 is 0.42MPa and the temperature is: 30°C.

[0048] Furthermore, another part of the liquid nitrogen in step 5 enters the liquid nitrogen storage tank 11 through the third end of the fifth three-way valve 34 , the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36 .

[0049] In order to explain the present invention in more detail, the present invention is further described in conjunction with embodiments. Specific embodiments are as follows:

[0050] Example 1

[0051] A device for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower 1, a main condenser evaporator 2 and a lower tower 3, the lower tower 3 being respectively connected to air ducts passing through a first tube pass of a low-pressure plate heat exchanger 4, a first tube pass of a high-pressure plate heat exchanger 5 and an expansion unit 6; an oxygen-rich liquid air outlet pipeline at the bottom of the lower tower 3 is connected to the middle of the upper tower 1 through a first tube pass of a subcooler 7 and a gas-liquid separator 8; the main condenser evaporator 2 is a parallel double main cooling four-layer fully immersed main condenser evaporator, a nitrogen outlet 9 at the upper part of the lower tower 3 is connected to a nitrogen side inlet of the parallel double main cooling four-layer fully immersed main condenser evaporator; the bottom of the upper tower 1 is connected to a parallel double main cooling four-layer fully immersed main condenser evaporator The oxygen side of the reactor is connected; the nitrogen side outlet of the parallel double main cooling four-layer fully immersed main condensing evaporator is respectively connected to the lower tower distillation liquid inlet 10 of the lower tower 3 and the liquid nitrogen storage tank 11; the bottom liquid oxygen outlet of the upper tower 1 and the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator are connected to the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5 and the downstream user device 14 through the first tee 12 in sequence; the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator is provided with a second tee 15 and a first regulating valve 16 in sequence between the first tee 12, and the outlet of the third end of the second tee 15 is respectively connected to the liquid oxygen storage tank 17 and the krypton-depleted xenon extraction device 18 through the second pipe pass of the supercooler 7. The middle and upper dirty nitrogen outlet of the lower tower 3 is connected to the second distillate inlet 19 of the upper tower 1 through the third tube pass of the subcooler 7. The top of the upper tower 1 is provided with a dirty nitrogen outlet 37. The dirty nitrogen outlet 37 is connected to the water cooling system 20 through the fourth tube pass of the subcooler 7 and the third tube pass of the high-pressure plate heat exchanger 5. The lower tower nitrogen outlet 21 of the middle and upper part of the lower tower 3 is connected to the pure argon evaporation system 22 through a pipeline. The pipeline between the lower tower nitrogen outlet 21 and the pure argon evaporation system 22 is provided with a third tee 23. The third end of the third tee 23 is connected to the low-pressure product nitrogen pipeline 24 through the second tube pass of the low-pressure plate heat exchanger 4. An annular liquid oxygen collecting tank 26 is provided on the tower wall of the lower part of the upper tower 1. The bottom of the annular liquid oxygen collecting tank 26 is provided with the tower bottom liquid oxygen outlet of the upper tower 1. The middle part of the annular liquid oxygen collecting tank 26 is the oxygen rising channel of the main condenser evaporator 2. The parallel double main cooling four-layer full immersion main condenser evaporator is respectively provided with an overflow pipeline 27. A second regulating valve 28 is provided between the bottom liquid oxygen outlet of the upper tower 1 and the first three-way valve 12. A fourth three-way valve 29 is provided at the outlet of the second pipe pass of the subcooler 7, the second end of the fourth three-way valve 29 is connected to the liquid oxygen storage tank 17 through a third regulating valve 30, and the third end of the fourth three-way valve 29 is connected to the depleted krypton xenon extraction device 18 through a fourth regulating valve 31. The gas phase outlet of the gas-liquid separator 8 is connected to the gas phase inlet 32 ​​of the upper tower, and the liquid phase outlet of the gas-liquid separator 8 is connected to the first distillation liquid inlet 33 of the upper tower in the middle of the upper tower 1, and the setting position of the first distillation liquid inlet 33 of the upper tower is lower than the setting position of the gas phase inlet 32 ​​of the upper tower.A fifth three-way valve 34 is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator and the lower tower distillation liquid inlet 10 of the lower tower 3. The second end of the fifth three-way valve 34 is connected to the lower tower distillation liquid inlet 10 through a fifth regulating valve 35, and the third end of the fifth three-way valve 34 is connected to the liquid nitrogen storage tank 11 through the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36.

[0052] A method for extracting krypton-poor xenon or oxygen-rich gas from a main condenser evaporator, the method comprising the following steps:

[0053] Step 1: The first air enters the lower tower 3 through the low-pressure plate heat exchanger 4, the second air enters the lower tower 3 through the high-pressure plate heat exchanger 5, and the third air enters the lower tower 3 through the expansion unit 6; the pressure of the first air is: 0.4~0.5Mpa, the temperature is: 15~20℃; the pressure after passing through the low-pressure plate heat exchanger 4 is: 0.4~0.5Mpa, the temperature is: -170~-175℃; the pressure of the second air is: 7~8Mpa, the temperature is: 25~35℃; the pressure after passing through the high-pressure plate heat exchanger 5 is: 7~8Mpa, the temperature is: -170~-175℃; the pressure after the third air is: 4.3~4.4Mpa, the temperature is: -105~-110℃; the pressure after passing through the expansion unit 6 is: 0.45~0.5Mpa, the temperature is: -165~-170℃;

[0054] The three air streams are rectified in the lower tower 3 with liquid nitrogen from the lower tower rectifying liquid inlet 10. After the rectification, the bottom of the lower tower 3 is oxygen-enriched liquid air, the middle and upper parts of the lower tower 3 are liquid air and dirty liquid nitrogen, and the top of the lower tower 3 is pure nitrogen and liquid nitrogen. The temperature of the liquid nitrogen is -175 to -180°C; the oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C.

[0055] Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower 3 and the first tube pass of the subcooler 7 and enters the gas-liquid separator 8 for gas-liquid separation. The gas phase after gas-liquid separation enters the upper tower 1 through the upper tower gas phase inlet 32, and the liquid phase after gas-liquid separation enters the upper tower 1 through the upper tower first distillation liquid inlet 33 as the upper tower distillation liquid; the gas phase temperature after the gas-liquid separation is: -180 to -185°C;

[0056] Step 3: The dirty liquid nitrogen enters the upper tower 1 through the dirty liquid nitrogen outlet in the upper part of the lower tower 3, the third tube pass of the subcooler 7 and the second distillation liquid inlet 19 of the upper tower as the upper tower distillation liquid; the temperature of the upper tower distillation liquid is: -185~-190℃;

[0057] Step 4: The liquid oxygen in the annular liquid oxygen collecting tank 26 at the bottom of the upper tower 1 overflows into the parallel double main cooling four-layer fully immersed main condenser evaporator, and the parallel double main cooling four-layer fully immersed main condenser evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower 3 to produce gaseous oxygen, and the gaseous oxygen and oxygen gas ascending channel enter the upper tower 1 for distillation, and the liquid phase after distillation enters the annular liquid oxygen collecting tank 26 and the main condenser evaporator 2, and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator through the corresponding overflow pipe 27; the temperature of the gaseous oxygen is: -175~-180℃;

[0058] Step 5: The pressure at the top of the lower tower 3 is: 0.44Mpa pure nitrogen enters through the nitrogen outlet (9 and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower 3 as the distillate of the lower tower through the second end of the fifth three-way 34, the fifth regulating valve 35 and the lower tower distillate inlet 10; the temperature of the liquid nitrogen is: -175~-180℃;

[0059] Step 6: When the downstream user device 14 needs liquid oxygen, close the second regulating valve 28, open the first regulating valve 16, and send the liquid oxygen from the parallel dual main cooling four-layer fully immersed main condenser evaporator into the downstream user device 14 through the first regulating valve 16, the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa and the temperature is: 30°C;

[0060] Step 7: The liquid nitrogen at the top of the lower tower 3 in the step 1 can be selectively fed into the low-pressure product nitrogen pipe network 24 or the pure argon evaporation system 22 as required. When it is necessary to enter the pure argon evaporation system 22, the liquid nitrogen directly enters the pure argon evaporation system 22 through the lower tower liquid nitrogen outlet 21 at the upper middle part of the lower tower 3 and the corresponding pipeline;

[0061] When it is necessary to enter the low-pressure product nitrogen pipeline network 24, the liquid nitrogen enters the low-pressure product nitrogen pipeline network 24 through the lower tower liquid nitrogen outlet 21 in the upper part of the lower tower 3, the third end of the third tee 23 and the second pipe pass of the low-pressure plate heat exchanger 4; the nitrogen pressure entering the low-pressure product nitrogen pipeline network 24 is 0.42MPa and the temperature is: 30°C.

[0062] Another part of the liquid nitrogen in step five enters the liquid nitrogen storage tank 11 through the third end of the fifth three-way valve 34 , the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36 .

[0063] Example 2

[0064] A device for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower 1, a main condenser evaporator 2 and a lower tower 3, the lower tower 3 being respectively connected to air ducts passing through a first tube pass of a low-pressure plate heat exchanger 4, a first tube pass of a high-pressure plate heat exchanger 5 and an expansion unit 6; an oxygen-rich liquid air outlet pipeline at the bottom of the lower tower 3 is connected to the middle of the upper tower 1 through a first tube pass of a subcooler 7 and a gas-liquid separator 8; the main condenser evaporator 2 is a parallel double main cooling four-layer fully immersed main condenser evaporator, a nitrogen outlet 9 at the upper part of the lower tower 3 is connected to a nitrogen side inlet of the parallel double main cooling four-layer fully immersed main condenser evaporator; the bottom of the upper tower 1 is connected to a parallel double main cooling four-layer fully immersed main condenser evaporator The oxygen side of the reactor is connected; the nitrogen side outlet of the parallel double main cooling four-layer fully immersed main condensing evaporator is respectively connected to the lower tower distillation liquid inlet 10 of the lower tower 3 and the liquid nitrogen storage tank 11; the bottom liquid oxygen outlet of the upper tower 1 and the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator are connected to the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5 and the downstream user device 14 through the first tee 12 in sequence; the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator is provided with a second tee 15 and a first regulating valve 16 in sequence between the first tee 12, and the outlet of the third end of the second tee 15 is respectively connected to the liquid oxygen storage tank 17 and the krypton-depleted xenon extraction device 18 through the second pipe pass of the supercooler 7. The middle and upper dirty nitrogen outlet of the lower tower 3 is connected to the second distillate inlet 19 of the upper tower 1 through the third tube pass of the subcooler 7. The top of the upper tower 1 is provided with a dirty nitrogen outlet 37. The dirty nitrogen outlet 37 is connected to the water cooling system 20 through the fourth tube pass of the subcooler 7 and the third tube pass of the high-pressure plate heat exchanger 5. The lower tower nitrogen outlet 21 of the middle and upper part of the lower tower 3 is connected to the pure argon evaporation system 22 through a pipeline. The pipeline between the lower tower nitrogen outlet 21 and the pure argon evaporation system 22 is provided with a third tee 23. The third end of the third tee 23 is connected to the low-pressure product nitrogen pipeline 24 through the second tube pass of the low-pressure plate heat exchanger 4. An annular liquid oxygen collecting tank 26 is provided on the tower wall of the lower part of the upper tower 1. The bottom of the annular liquid oxygen collecting tank 26 is provided with the tower bottom liquid oxygen outlet of the upper tower 1. The middle part of the annular liquid oxygen collecting tank 26 is the oxygen rising channel of the main condenser evaporator 2. The parallel double main cooling four-layer full immersion main condenser evaporator is respectively provided with an overflow pipeline 27. A second regulating valve 28 is provided between the bottom liquid oxygen outlet of the upper tower 1 and the first three-way valve 12. A fourth three-way valve 29 is provided at the outlet of the second pipe pass of the subcooler 7, the second end of the fourth three-way valve 29 is connected to the liquid oxygen storage tank 17 through a third regulating valve 30, and the third end of the fourth three-way valve 29 is connected to the depleted krypton xenon extraction device 18 through a fourth regulating valve 31. The gas phase outlet of the gas-liquid separator 8 is connected to the gas phase inlet 32 ​​of the upper tower, and the liquid phase outlet of the gas-liquid separator 8 is connected to the first distillation liquid inlet 33 of the upper tower in the middle of the upper tower 1, and the setting position of the first distillation liquid inlet 33 of the upper tower is lower than the setting position of the gas phase inlet 32 ​​of the upper tower.A fifth three-way valve 34 is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator and the lower tower distillation liquid inlet 10 of the lower tower 3. The second end of the fifth three-way valve 34 is connected to the lower tower distillation liquid inlet 10 through a fifth regulating valve 35, and the third end of the fifth three-way valve 34 is connected to the liquid nitrogen storage tank 11 through the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36.

[0065] A method for extracting krypton-poor xenon or oxygen-rich gas from a main condenser evaporator, the method comprising the following steps:

[0066] Step 1: The first air enters the lower tower 3 through the low-pressure plate heat exchanger 4, the second air enters the lower tower 3 through the high-pressure plate heat exchanger 5, and the third air enters the lower tower 3 through the expansion unit 6; the pressure of the first air is: 0.4~0.5Mpa, the temperature is: 15~20℃; the pressure after passing through the low-pressure plate heat exchanger 4 is: 0.4~0.5Mpa, the temperature is: -170~-175℃; the pressure of the second air is: 7~8Mpa, the temperature is: 25~35℃; the pressure after passing through the high-pressure plate heat exchanger 5 is: 7~8Mpa, the temperature is: -170~-175℃; the pressure after the third air is: 4.3~4.4Mpa, the temperature is: -105~-110℃; the pressure after passing through the expansion unit 6 is: 0.45~0.5Mpa, the temperature is: -165~-170℃;

[0067] The three air streams are rectified in the lower tower 3 with liquid nitrogen from the lower tower rectifying liquid inlet 10. After the rectification, the bottom of the lower tower 3 is oxygen-enriched liquid air, the middle and upper parts of the lower tower 3 are liquid air and dirty liquid nitrogen, and the top of the lower tower 3 is pure nitrogen and liquid nitrogen. The temperature of the liquid nitrogen is -175 to -180°C; the oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C.

[0068] Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower 3 and the first tube pass of the subcooler 7 and enters the gas-liquid separator 8 for gas-liquid separation. The gas phase after gas-liquid separation enters the upper tower 1 through the upper tower gas phase inlet 32, and the liquid phase after gas-liquid separation enters the upper tower 1 through the upper tower first distillation liquid inlet 33 as the upper tower distillation liquid; the gas phase temperature after the gas-liquid separation is: -180 to -185°C;

[0069] Step 3: The dirty liquid nitrogen enters the upper tower 1 through the dirty liquid nitrogen outlet in the upper part of the lower tower 3, the third tube pass of the subcooler 7 and the second distillation liquid inlet 19 of the upper tower as the upper tower distillation liquid; the temperature of the upper tower distillation liquid is: -185~-190℃;

[0070] Step 4: The liquid oxygen in the annular liquid oxygen collecting tank 26 at the bottom of the upper tower 1 overflows into the parallel double main cooling four-layer fully immersed main condenser evaporator, and the parallel double main cooling four-layer fully immersed main condenser evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower 3 to produce gaseous oxygen, and the gaseous oxygen and oxygen gas ascending channel enter the upper tower 1 for distillation, and the liquid phase after distillation enters the annular liquid oxygen collecting tank 26 and the main condenser evaporator 2, and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator through the corresponding overflow pipe 27; the temperature of the gaseous oxygen is: -175~-180℃;

[0071] Step 5: The pressure at the top of the lower tower 3 is: 0.44Mpa pure nitrogen enters through the nitrogen outlet (9 and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower 3 as the distillate of the lower tower through the second end of the fifth three-way 34, the fifth regulating valve 35 and the lower tower distillate inlet 10; the temperature of the liquid nitrogen is: -175~-180℃;

[0072] Step 6: When both the downstream user device 14 and the liquid oxygen storage tank 17 need liquid oxygen, open the first regulating valve 16 and the third regulating valve 30, close the second regulating valve 28 and the fourth regulating valve 31, so that the liquid oxygen at the bottom of the upper tower 1 is sent to the downstream user device 14 through the first tee 12, the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5; the liquid oxygen of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator enters the liquid oxygen storage tank 17 through the outlet of the third end of the second tee 15, the second pipe pass of the subcooler 7 and the third regulating valve 30; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa, and the temperature is: 30°C; the liquid oxygen temperature entering the liquid oxygen storage tank 17 is: -186°C;

[0073] Step 7: The liquid nitrogen at the top of the lower tower 3 in the step 1 can be selectively fed into the low-pressure product nitrogen pipe network 24 or the pure argon evaporation system 22 as required. When it is necessary to enter the pure argon evaporation system 22, the liquid nitrogen directly enters the pure argon evaporation system 22 through the lower tower liquid nitrogen outlet 21 at the upper middle part of the lower tower 3 and the corresponding pipeline;

[0074] When it is necessary to enter the low-pressure product nitrogen pipeline network 24, the liquid nitrogen enters the low-pressure product nitrogen pipeline network 24 through the lower tower liquid nitrogen outlet 21 in the upper part of the lower tower 3, the third end of the third tee 23 and the second pipe pass of the low-pressure plate heat exchanger 4; the nitrogen pressure entering the low-pressure product nitrogen pipeline network 24 is 0.42MPa and the temperature is: 30°C.

[0075] Furthermore, another part of the liquid nitrogen in step five enters the liquid nitrogen storage tank 11 through the third end of the fifth three-way valve 34 , the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36 .

[0076] Example 3

[0077] A device for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower 1, a main condenser evaporator 2 and a lower tower 3, the lower tower 3 being respectively connected to air ducts passing through a first tube pass of a low-pressure plate heat exchanger 4, a first tube pass of a high-pressure plate heat exchanger 5 and an expansion unit 6; an oxygen-rich liquid air outlet pipeline at the bottom of the lower tower 3 is connected to the middle of the upper tower 1 through a first tube pass of a subcooler 7 and a gas-liquid separator 8; the main condenser evaporator 2 is a parallel double main cooling four-layer fully immersed main condenser evaporator, a nitrogen outlet 9 at the upper part of the lower tower 3 is connected to a nitrogen side inlet of the parallel double main cooling four-layer fully immersed main condenser evaporator; the bottom of the upper tower 1 is connected to a parallel double main cooling four-layer fully immersed main condenser evaporator The oxygen side of the reactor is connected; the nitrogen side outlet of the parallel double main cooling four-layer fully immersed main condensing evaporator is respectively connected to the lower tower distillation liquid inlet 10 of the lower tower 3 and the liquid nitrogen storage tank 11; the bottom liquid oxygen outlet of the upper tower 1 and the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator are connected to the high-pressure liquid oxygen pump 13 and the second pipe pass of the high-pressure plate heat exchanger 5 and the downstream user device 14 through the first tee 12 in sequence; the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator is provided with a second tee 15 and a first regulating valve 16 in sequence between the first tee 12, and the outlet of the third end of the second tee 15 is respectively connected to the liquid oxygen storage tank 17 and the krypton-depleted xenon extraction device 18 through the second pipe pass of the supercooler 7. The middle and upper dirty nitrogen outlet of the lower tower 3 is connected to the second distillate inlet 19 of the upper tower 1 through the third tube pass of the subcooler 7. The top of the upper tower 1 is provided with a dirty nitrogen outlet 37. The dirty nitrogen outlet 37 is connected to the water cooling system 20 through the fourth tube pass of the subcooler 7 and the third tube pass of the high-pressure plate heat exchanger 5. The lower tower nitrogen outlet 21 of the middle and upper part of the lower tower 3 is connected to the pure argon evaporation system 22 through a pipeline. The pipeline between the lower tower nitrogen outlet 21 and the pure argon evaporation system 22 is provided with a third tee 23. The third end of the third tee 23 is connected to the low-pressure product nitrogen pipeline 24 through the second tube pass of the low-pressure plate heat exchanger 4. An annular liquid oxygen collecting tank 26 is provided on the tower wall of the lower part of the upper tower 1. The bottom of the annular liquid oxygen collecting tank 26 is provided with the tower bottom liquid oxygen outlet of the upper tower 1. The middle part of the annular liquid oxygen collecting tank 26 is the oxygen rising channel of the main condenser evaporator 2. The parallel double main cooling four-layer full immersion main condenser evaporator is respectively provided with an overflow pipeline 27. A second regulating valve 28 is provided between the bottom liquid oxygen outlet of the upper tower 1 and the first three-way valve 12. A fourth three-way valve 29 is provided at the outlet of the second pipe pass of the subcooler 7, the second end of the fourth three-way valve 29 is connected to the liquid oxygen storage tank 17 through a third regulating valve 30, and the third end of the fourth three-way valve 29 is connected to the depleted krypton xenon extraction device 18 through a fourth regulating valve 31. The gas phase outlet of the gas-liquid separator 8 is connected to the gas phase inlet 32 ​​of the upper tower, and the liquid phase outlet of the gas-liquid separator 8 is connected to the first distillation liquid inlet 33 of the upper tower in the middle of the upper tower 1, and the setting position of the first distillation liquid inlet 33 of the upper tower is lower than the setting position of the gas phase inlet 32 ​​of the upper tower.A fifth three-way valve 34 is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator and the lower tower distillation liquid inlet 10 of the lower tower 3. The second end of the fifth three-way valve 34 is connected to the lower tower distillation liquid inlet 10 through a fifth regulating valve 35, and the third end of the fifth three-way valve 34 is connected to the liquid nitrogen storage tank 11 through the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36.

[0078] A method for extracting krypton-poor xenon or oxygen-rich gas from a main condenser evaporator, the method comprising the following steps:

[0079] Step 1: The first air enters the lower tower 3 through the low-pressure plate heat exchanger 4, the second air enters the lower tower 3 through the high-pressure plate heat exchanger 5, and the third air enters the lower tower 3 through the expansion unit 6; the pressure of the first air is: 0.4~0.5Mpa, the temperature is: 15~20℃; the pressure after passing through the low-pressure plate heat exchanger 4 is: 0.4~0.5Mpa, the temperature is: -170~-175℃; the pressure of the second air is: 7~8Mpa, the temperature is: 25~35℃; the pressure after passing through the high-pressure plate heat exchanger 5 is: 7~8Mpa, the temperature is: -170~-175℃; the pressure after the third air is: 4.3~4.4Mpa, the temperature is: -105~-110℃; the pressure after passing through the expansion unit 6 is: 0.45~0.5Mpa, the temperature is: -165~-170℃;

[0080] The three air streams are rectified in the lower tower 3 with liquid nitrogen from the lower tower rectifying liquid inlet 10. After the rectification, the bottom of the lower tower 3 is oxygen-enriched liquid air, the middle and upper parts of the lower tower 3 are liquid air and dirty liquid nitrogen, and the top of the lower tower 3 is pure nitrogen and liquid nitrogen. The temperature of the liquid nitrogen is -175 to -180°C; the oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C.

[0081] Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower 3 and the first tube pass of the subcooler 7 and enters the gas-liquid separator 8 for gas-liquid separation. The gas phase after gas-liquid separation enters the upper tower 1 through the upper tower gas phase inlet 32, and the liquid phase after gas-liquid separation enters the upper tower 1 through the upper tower first distillation liquid inlet 33 as the upper tower distillation liquid; the gas phase temperature after the gas-liquid separation is: -180 to -185°C;

[0082] Step 3: The dirty liquid nitrogen enters the upper tower 1 through the dirty liquid nitrogen outlet in the upper part of the lower tower 3, the third tube pass of the subcooler 7 and the second distillation liquid inlet 19 of the upper tower as the upper tower distillation liquid; the temperature of the upper tower distillation liquid is: -185~-190℃;

[0083] Step 4: The liquid oxygen in the annular liquid oxygen collecting tank 26 at the bottom of the upper tower 1 overflows into the parallel double main cooling four-layer fully immersed main condenser evaporator, and the parallel double main cooling four-layer fully immersed main condenser evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower 3 to produce gaseous oxygen, and the gaseous oxygen and oxygen gas ascending channel enter the upper tower 1 for distillation, and the liquid phase after distillation enters the annular liquid oxygen collecting tank 26 and the main condenser evaporator 2, and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condenser evaporator through the corresponding overflow pipe 27; the temperature of the gaseous oxygen is: -175~-180℃;

[0084] Step 5: The pressure at the top of the lower tower 3 is: 0.44Mpa pure nitrogen enters through the nitrogen outlet (9 and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower 3 as the distillate of the lower tower through the second end of the fifth three-way 34, the fifth regulating valve 35 and the lower tower distillate inlet 10; the temperature of the liquid nitrogen is: -175~-180℃;

[0085] Step 6: When the downstream user device 14 and the krypton-depleted xenon extraction device 18 are connected, the first regulating valve 16 and the third regulating valve 30 are closed, and the fourth regulating valve 31 and the second regulating valve 28 are opened, so that the liquid oxygen at the bottom of the upper tower 1 is sent to the downstream user device 14 through the first tee 12, the high-pressure liquid oxygen pump 13 and the second pipe side of the high-pressure plate heat exchanger 5; the liquid oxygen of the parallel dual-main cooling four-layer full-immersion main condenser evaporator enters the krypton-depleted xenon extraction device 18 through the outlet of the third end of the second tee 15, the second pipe side of the subcooler 7 and the fourth regulating valve 31; the gas oxygen pressure entering the downstream user device 14 is 7.6Mpa, and the temperature is: 30°C; the krypton content in the liquid oxygen entering the krypton-depleted xenon extraction device 18 is not less than 180ppm, and the xenon content is not less than 20ppm;

[0086] Step 7: The liquid nitrogen at the top of the lower tower 3 in the step 1 can be selectively fed into the low-pressure product nitrogen pipe network 24 or the pure argon evaporation system 22 as required. When it is necessary to enter the pure argon evaporation system 22, the liquid nitrogen directly enters the pure argon evaporation system 22 through the lower tower liquid nitrogen outlet 21 at the upper middle part of the lower tower 3 and the corresponding pipeline;

[0087] When it is necessary to enter the low-pressure product nitrogen pipeline network 24, the liquid nitrogen enters the low-pressure product nitrogen pipeline network 24 through the lower tower liquid nitrogen outlet 21 in the upper part of the lower tower 3, the third end of the third tee 23 and the second pipe pass of the low-pressure plate heat exchanger 4; the nitrogen pressure entering the low-pressure product nitrogen pipeline network 24 is 0.42MPa and the temperature is: 30°C.

[0088] Furthermore, another part of the liquid nitrogen in step five enters the liquid nitrogen storage tank 11 through the third end of the fifth three-way valve 34 , the fifth pipe pass of the subcooler 7 and the sixth regulating valve 36 .

[0089] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connection", "connected" and the like should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can also be the internal connection of two elements; it can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The above examples are only specific descriptions of the feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent implementation methods, changes and modifications that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for extracting krypton-depleted xenon or oxygen-rich by a main condenser evaporator, the device comprising a main distillation tower, the main distillation tower comprising an upper tower (1), a main condenser evaporator (2) and a lower tower (3), characterized in that: The lower tower (3) is respectively connected to the first tube pass of the low-pressure plate heat exchanger (4), the first tube pass of the high-pressure plate heat exchanger (5), and the air pipeline of the expansion unit (6); the oxygen-enriched liquid air outlet pipeline at the bottom of the lower tower (3) is connected to the middle part of the upper tower (1) through the first tube pass of the subcooler (7) and the gas-liquid separator (8); The main condenser evaporator (2) is a parallel dual-main cooling four-layer fully immersed main condenser evaporator, and the nitrogen outlet (9) at the upper part of the lower tower (3) is connected to the nitrogen side inlet of the parallel dual-main cooling four-layer fully immersed main condenser evaporator; The bottom of the upper tower (1) is connected to the oxygen side of a parallel dual-main cooling four-layer fully immersed main condenser evaporator; The nitrogen side outlet of the parallel dual main cooling four-layer fully immersed main condensing evaporator is respectively connected to the lower tower distillation liquid inlet (10) of the lower tower (3) and the liquid nitrogen storage tank (11); The bottom liquid oxygen outlet of the upper tower (1) and the liquid oxygen outlet side of the parallel dual main cooling four-layer fully immersed main condenser evaporator are connected to the high-pressure liquid oxygen pump (13) and the second tube pass of the high-pressure plate heat exchanger (5) and the downstream user device (14) in sequence through the first tee (12); The liquid oxygen outlet side of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator is provided with a second tee (15) and a first regulating valve (16) in sequence between the first tee (12), and the outlet of the third end of the second tee (15) is connected to the liquid oxygen storage tank (17) and the krypton-depleted xenon extraction device (18) respectively through the second pipe pass of the subcooler (7); The dirty nitrogen outlet at the upper part of the lower tower (3) is connected to the second distillation liquid inlet (19) of the upper tower (1) through the third tube pass of the subcooler (7); the top of the upper tower (1) is provided with a dirty nitrogen outlet (37); the dirty nitrogen outlet (37) is connected to the water cooling system (20) through the fourth tube pass of the subcooler (7) and the third tube pass of the high-pressure plate heat exchanger (5); A lower tower nitrogen outlet (21) at the upper middle portion of the lower tower (3) is connected to a pure argon evaporation system (22) via a pipeline, a third tee (23) is provided on the pipeline between the lower tower nitrogen outlet (21) and the pure argon evaporation system (22), and a third end of the third tee (23) is connected to a low-pressure product nitrogen pipeline network (24) via a second pipe pass of the low-pressure plate heat exchanger (4).

2. The device for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 1, characterized in that: An annular liquid oxygen collecting tank (26) is provided on the tower wall at the lower part of the upper tower (1); a bottom liquid oxygen outlet of the upper tower (1) is provided at the bottom of the annular liquid oxygen collecting tank (26); the middle part of the annular liquid oxygen collecting tank (26) is an oxygen ascending channel of the main condenser evaporator (2); and overflow pipes (27) are respectively provided on the parallel dual main cooling four-layer fully immersed main condenser evaporators.

3. The device for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 1, characterized in that: A second regulating valve (28) is provided between the liquid oxygen outlet at the bottom of the upper tower (1) and the first three-way valve (12).

4. The device for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 1, characterized in that: A fourth tee (29) is provided at the outlet of the second pipe pass of the subcooler (7); a second end of the fourth tee (29) is connected to the liquid oxygen storage tank (17) via a third regulating valve (30); and a third end of the fourth tee (29) is connected to the krypton-depleted xenon extraction device (18) via a fourth regulating valve (31).

5. The device for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 1, characterized in that: The gas phase outlet of the gas-liquid separator (8) is connected to the gas phase inlet (32) of the upper tower, and the liquid phase outlet of the gas-liquid separator (8) is connected to the first distillation liquid inlet (33) of the upper tower in the middle of the upper tower (1). The setting position of the first distillation liquid inlet (33) of the upper tower is lower than the setting position of the gas phase inlet (32) of the upper tower.

6. The device for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 1, characterized in that: A fifth tee (34) is provided between the nitrogen side outlet of the parallel dual-main-cooling four-layer fully immersed main condenser evaporator and the lower tower distillate inlet (10) of the lower tower (3); a second end of the fifth tee (34) is connected to the lower tower distillate inlet (10) via a fifth regulating valve (35); and a third end of the fifth tee (34) is connected to the liquid nitrogen storage tank (11) via a fifth pipe pass of the subcooler (7) and a sixth regulating valve (36).

7. A method for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator as claimed in any one of claims 1 to 6, characterized in that: The extraction method comprises the following steps: Step 1: The first stream of air enters the lower tower (3) through the low-pressure plate heat exchanger (4), the second stream of air enters the lower tower (3) through the high-pressure plate heat exchanger (5), and the third stream of air enters the lower tower (3) through the expansion unit (6); the pressure of the first stream of air is 0.4-0.5 MPa and the temperature is 15-20°C; the pressure after passing through the low-pressure plate heat exchanger (4) is 0.4-0.5 MPa and the temperature is -170--175°C; the pressure of the second stream of air is 7-8 MPa and the temperature is 25-35°C; the pressure after passing through the high-pressure plate heat exchanger (5) is 7-8 MPa and the temperature is -170--175°C; the pressure after the third stream of air is 4.3-4.4 MPa, The temperature is -105 to -110°C; the pressure after passing through the expansion unit (6) is 0.45 to 0.5 MPa, and the temperature is -165 to -170°C; The three air streams are rectified in the lower tower (3) with liquid nitrogen from the lower tower rectifier inlet (10). After the rectification, the bottom of the lower tower (3) is oxygen-enriched liquid air, the middle and upper parts of the lower tower (3) are liquid air and dirty liquid nitrogen, and the top of the lower tower (3) is pure nitrogen and liquid nitrogen. The temperature of the liquid nitrogen is -175 to -180°C. The oxygen content of the oxygen-enriched liquid air is 36 to 39%, and the temperature is -184°C. Step 2: The oxygen-rich liquid air passes through the oxygen-rich liquid air outlet pipe at the bottom of the lower tower (3) and the first tube pass of the subcooler (7) and enters the gas-liquid separator (8) for gas-liquid separation. The gas phase after the gas-liquid separation enters the upper tower (1) through the upper tower gas phase inlet (32). The liquid phase after the gas-liquid separation enters the upper tower (1) through the upper tower first distillation liquid inlet (33) as the upper tower distillation liquid. The temperature of the gas phase after the gas-liquid separation is -180 to -185°C. Step 3: the dirty liquid nitrogen enters the upper tower (1) through the dirty liquid nitrogen outlet in the upper part of the lower tower (3), the third tube pass of the subcooler (7) and the second distillate inlet (19) of the upper tower as the upper tower distillate; the temperature of the upper tower distillate is: -185 to -190°C; Step 4: The liquid oxygen in the annular liquid oxygen collecting tank (26) at the bottom of the upper tower (1) overflows into the parallel double main cooling four-layer fully immersed main condensing evaporator, and the parallel double main cooling four-layer fully immersed main condensing evaporator is heated and evaporated by the nitrogen from the bottom of the lower tower (3) to produce gaseous oxygen, and the gaseous oxygen enters the upper tower (1) through the oxygen gas ascending channel for distillation, and the liquid phase after distillation enters the annular liquid oxygen collecting tank (26) and the main condensing evaporator (2), and enters the liquid oxygen outlet side of the parallel double main cooling four-layer fully immersed main condensing evaporator through the corresponding overflow pipe (27); the temperature of the gaseous oxygen is: -175 to -180°C; Step 5: The pressure at the top of the lower tower (3) is: 0.44 MPa pure nitrogen enters through the nitrogen outlet (9) and the nitrogen side inlet of the parallel double-layer fully immersed main condenser evaporator, enters the parallel double-main-cooling four-layer fully immersed main condenser evaporator, exchanges heat with liquid oxygen, and condenses into liquid nitrogen. Part of the liquid nitrogen enters the lower tower (3) through the second end of the fifth three-way (34), the fifth regulating valve (35) and the lower tower distillate inlet (10) as the distillate of the lower tower; the temperature of the liquid nitrogen is: -175 to -180°C; Step 6: When the downstream user device (14) needs liquid oxygen, the second regulating valve (28) is closed and the first regulating valve (16) is opened, so that the liquid oxygen in the parallel dual main cooling four-layer fully immersed main condenser evaporator is sent to the downstream user device (14) through the first regulating valve (16), the high-pressure liquid oxygen pump (13) and the second pipe pass of the high-pressure plate heat exchanger (5); the pressure of the gas oxygen entering the downstream user device (14) is 7.6 MPa and the temperature is: 30°C; Step 7: When both the downstream user device (14) and the liquid oxygen storage tank (17) need liquid oxygen, the first regulating valve (16) and the third regulating valve (30) are opened, and the second regulating valve (28) and the fourth regulating valve (31) are closed, so that the liquid oxygen at the bottom of the upper tower (1) is sent to the downstream user device (14) through the first tee (12), the high-pressure liquid oxygen pump (13) and the second pipe side of the high-pressure plate heat exchanger (5); the liquid oxygen of the parallel dual main cooling four-layer full immersion main condenser evaporator enters the liquid oxygen storage tank (17) through the outlet of the third end of the second tee (15), the second pipe side of the subcooler (7) and the third regulating valve (30); the gas oxygen pressure entering the downstream user device (14) is 7.6 MPa and the temperature is: 30°C; the liquid oxygen temperature entering the liquid oxygen storage tank (17) is: -186°C; Step 8: When the downstream user device (14) and the krypton-depleted xenon extraction device (18) are connected, the first regulating valve (16) and the third regulating valve (30) are closed, and the fourth regulating valve (31) and the second regulating valve (28) are opened, so that the liquid oxygen at the bottom of the upper tower (1) is sent to the downstream user device (14) through the first tee (12), the high-pressure liquid oxygen pump (13) and the second pipe side of the high-pressure plate heat exchanger (5); the liquid oxygen of the parallel dual-main cooling four-layer full-immersion main condenser evaporator enters the krypton-depleted xenon extraction device (18) through the outlet of the third end of the second tee (15), the second pipe side of the subcooler (7) and the fourth regulating valve (31); the gas oxygen pressure entering the downstream user device (14) is 7.6 MPa and the temperature is: 30°C; the krypton content in the liquid oxygen entering the krypton-depleted xenon extraction device (18) is not less than 180 ppm, and the xenon content is not less than 20 ppm; Step nine: the liquid nitrogen at the top of the lower tower (3) in the step one can be selectively fed into the low-pressure product nitrogen pipeline (24) or the pure argon evaporation system (22) as required. When it is required to enter the pure argon evaporation system (22), the liquid nitrogen directly enters the pure argon evaporation system (22) through the lower tower liquid nitrogen outlet (21) at the upper middle part of the lower tower (3) and the corresponding pipeline; When it is necessary to enter the low-pressure product nitrogen pipeline network (24), the liquid nitrogen enters the low-pressure product nitrogen pipeline network (24) through the lower tower liquid nitrogen outlet (21) in the upper middle part of the lower tower (3), the third end of the third tee (23) and the second pipe side of the low-pressure plate heat exchanger (4); the nitrogen pressure entering the low-pressure product nitrogen pipeline network (24) is 0.42 MPa and the temperature is 30°C.

8. The method for extracting krypton-depleted xenon or oxygen-rich gas by a main condenser evaporator according to claim 7, characterized in that: Another portion of the liquid nitrogen in step five enters the liquid nitrogen storage tank (11) through the third end of the fifth three-way valve (34), the fifth pipe pass of the subcooler (7) and the sixth regulating valve (36).

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