Energy-saving system and process for recycling oxygen from high-temperature oxygen-rich flue gas

Abstract

The application discloses an energy-saving system for recycling oxygen from high-temperature oxygen-rich flue gas, which comprises a water washing mechanism connected with the high-temperature oxygen-rich flue gas, a compressor unit connected with the water washing system pipeline, a compressor outlet heat exchanger connected with the compressor unit pipeline, a gas-liquid separation tank connected with the compressor outlet heat exchanger pipeline, a temperature swing adsorption isobaric drying mechanism and a pressure swing adsorption purification mechanism connected with the gas-liquid separation tank pipeline, a dust removal and filtration mechanism connected with the temperature swing adsorption isobaric drying mechanism and the pressure swing adsorption purification mechanism for processing the gas, and a cooling mechanism for cooling the water washing mechanism and the compressor outlet heat exchanger. The application has low recycling cost. The oxygen-rich flue gas is divided into two parts, one part is subjected to temperature swing adsorption drying, and the other part is subjected to pressure swing adsorption purification. The two product gases are mixed to obtain high-purity oxygen, thereby effectively reducing the recycling cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas separation technology and purification, in particular to an energy-saving process system for high-temperature oxygen-rich flue gas purification oxygen recycling and a process thereof. BACKGROUND

[0002] Lithium ion batteries are widely used in production and life due to their high voltage, high energy density, low self-discharge efficiency, long cycle life, no memory effect and environmental protection. At present, the ternary positive electrode material (lithium nickel cobalt manganese oxide) of lithium battery is a new type of positive electrode material, which is prepared by using nickel salt, cobalt salt and manganese salt as raw materials. Compared with other positive electrode materials, the comprehensive performance of the ternary material has the most advantages, and the ternary material has become the mainstream of positive electrode materials. The production process of the ternary positive electrode material is to mix the compounds of nickel, cobalt and manganese, and to prepare a ternary precursor at high temperature. The precursor is mixed uniformly with a lithium compound (lithium hydroxide or lithium carbonate) and is sintered in an oxygen atmosphere. During the sintering process, carbon dioxide and water vapor are generated due to the synthesis reaction, so the generated high-temperature oxygen-rich flue gas contains components such as carbon dioxide and water vapor. In addition, the roller kiln for sintering contains a large number of mechanical gaps, and the oxygen-rich flue gas will absorb air during the extraction process by the Roots blower, resulting in the presence of nitrogen components in the oxygen-rich flue gas.

[0003] At present, most of the remaining oxygen-rich flue gas generated during the sintering process of the ternary positive electrode material of the lithium battery is directly discharged into the atmosphere after environmental dust removal treatment, without considering the purification and reuse of the high-concentration oxygen in the oxygen-rich flue gas. This results in a large amount of oxygen used in the production process, high energy consumption, and increased production cost of mixed sintering, thereby increasing the production cost of the positive electrode material of the lithium battery. Only a few enterprises have installed oxygen-rich flue gas recycling devices, which have reduced the production cost of the positive electrode material of the lithium battery. However, a small amount of air is absorbed before the high-temperature oxygen-rich flue gas is recovered, resulting in a low oxygen recovery rate and high recovery cost of the nitrogen removal device. For example, in the prior art, document No. CN108786371A discloses a high-temperature oxygen-rich flue gas oxygen recovery system and a recovery method thereof, which can purify and reuse the oxygen in the high-temperature oxygen-rich flue gas. However, the nitrogen in the oxygen-rich flue gas is not treated, and the device needs to rely on a nitrogen removal device, which has a high recovery cost. The oxygen recovery rate is low, and efficient oxygen recovery cannot be achieved. SUMMARY

[0004] To overcome the problems in the prior art, the present application provides an energy-saving process system for high-temperature oxygen-rich flue gas purification oxygen recycling, which has low recovery cost, low recovery cost and high oxygen recovery rate.

[0005] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0006] An energy-saving system for high-temperature oxygen-rich flue gas purification and oxygen recycling, comprising a water washing mechanism connected to high-temperature oxygen-rich flue gas, a compressor unit connected to the water washing mechanism, a compressor outlet heat exchanger connected to the compressor unit, a gas-liquid separation tank connected to the compressor outlet heat exchanger, an adsorption isotherm drying mechanism and a pressure swing adsorption purification mechanism connected to the gas-liquid separation tank, a dust removal and filtration mechanism connected to the adsorption isotherm drying mechanism and the pressure swing adsorption purification mechanism, and a cooling mechanism for cooling the water washing mechanism and the compressor outlet heat exchanger, wherein the output end of the adsorption isotherm drying mechanism is connected to the output end of the pressure swing adsorption purification mechanism by a pipeline, and the pipeline is connected to the dust removal and filtration mechanism, and the pressure swing adsorption purification mechanism is connected to the water washing mechanism.

[0007] Further, the water washing mechanism comprises a flue gas inlet pipe for connecting to high-temperature oxygen-rich flue gas and a normal-temperature water pipe for filling normal-temperature water, a first water washing tower connected to the flue gas inlet pipe and the normal-temperature water pipe respectively, a drain pipe and a second water washing tower connected to the first water washing tower, and an outlet pipe connected to the second water washing tower and the compressor unit respectively, wherein the cooling mechanism is connected to the second water washing tower by a pipeline, and the pressure swing adsorption purification mechanism is connected to the first water washing tower.

[0008] Specifically, the temperature swing adsorption constant pressure drying mechanism comprises a drying inlet gas pipe connected with a gas-liquid separation tank, a first gas conveying pipe, a second gas conveying pipe and a third gas conveying pipe connected with the drying inlet gas pipe, a fourth gas conveying pipe connected with the third gas conveying pipe, a first adsorption tower and a second adsorption tower connected with the first gas conveying pipe and the second gas conveying pipe respectively, a first output pipe and a second output pipe connected with the first adsorption tower and the second adsorption tower at the bottom respectively, a dry product gas pipe connected with the first output pipe and the second output pipe respectively and used for outputting product gas, a pre-drying tower connected with the third gas conveying pipe, a heater connected with the pre-drying tower by a pipeline, a fifth gas conveying pipe connected with the heater at one end and connected with the first output pipe and the second output pipe by pipelines at the other end respectively, a condenser connected with the fourth gas conveying pipe, a gas-liquid separator connected with the condenser by a pipeline, a sixth gas conveying pipe connected between the third gas conveying pipe and the fourth gas conveying pipe, a seventh gas conveying pipe connected with the sixth gas conveying pipe at one end and connected with the first output pipe and the second output pipe by pipelines at the other end respectively, a plurality of first on-off valves installed on the first gas conveying pipe, the second gas conveying pipe, the third gas conveying pipe, the fourth gas conveying pipe, the first output pipe, the second output pipe, the connecting pipeline of the fifth gas conveying pipe and the first output pipe, the connecting pipeline of the fifth gas conveying pipe and the second output pipe, the connecting pipeline of the seventh gas conveying pipe and the first gas conveying pipe and the connecting pipeline of the seventh gas conveying pipe and the second gas conveying pipe respectively, and two second on-off valves installed on the sixth gas conveying pipe, wherein the gas-liquid separator is connected with the drying inlet gas pipe by a pipeline, the seventh gas conveying pipe is connected with the sixth gas conveying pipe and located between the two second on-off valves, and the dry product gas pipe is connected with the output pipeline of the pressure swing adsorption purification mechanism.

[0009] Specifically, the pressure swing adsorption purification mechanism comprises a pressure swing adsorption inlet gas pipe connected with a gas-liquid separation tank, a plurality of pressure swing adsorption towers connected with the pressure swing adsorption inlet gas pipe at the bottom, a pressure swing adsorption output gas pipe connected with the top of each pressure swing adsorption tower, a pressure swing adsorption product gas pipe connected with each pressure swing adsorption output gas pipe and connected with a dry product gas pipe, an equalizing mechanism connected with each pressure swing adsorption output gas pipe, a first regulating valve connected with the pressure swing adsorption product gas pipe and the equalizing mechanism at two ends respectively, a pressure swing adsorption exhaust pipe connected with the bottom pipeline of each pressure swing adsorption tower, a pressure swing adsorption recovery pipe connected with the bottom pipeline of each pressure swing adsorption tower at one end and connected with a first water washing tower at the other end, a third on-off valve arranged on the pressure swing adsorption output gas pipe, the connecting pipeline of the pressure swing adsorption inlet gas pipe and the bottom of the pressure swing adsorption tower, the connecting pipeline of the pressure swing adsorption exhaust pipe and the bottom of the pressure swing adsorption tower, and the connecting pipeline of the pressure swing adsorption recovery pipe and the bottom of the pressure swing adsorption tower respectively, a pressure regulating valve and a dust removal and filtration system installed on the pressure swing adsorption product gas pipe, a recovery regulating valve installed on the pressure swing adsorption recovery pipe, and a vacuum pump installed on the pressure swing adsorption exhaust pipe, wherein the pressure swing adsorption product gas pipe is connected with a dust removal and filtration mechanism.

[0010] Specifically, the pressure equalizing mechanism comprises a plurality of pressure equalizing pipes connected with each pressure swing adsorption output gas pipe respectively, and a pressure equalizing switch valve installed on the pressure equalizing pipe and the connecting pipe of each pressure swing adsorption output gas pipe.

[0011] Specifically, the number of the pressure swing adsorption towers is at least three.

[0012] Specifically, the cooling mechanism comprises a water chiller connected with the compressor outlet heat exchanger pipe, and a low-temperature heat exchanger connected with the water chiller and the second water washing tower respectively.

[0013] The application also provides an energy-saving system and process for recycling oxygen gas purified from high-temperature oxygen-rich flue gas.

[0014] S1, water washing: the water washing mechanism is used to wash the high-temperature oxygen-rich flue gas, so as to obtain low-temperature oxygen-rich mixed gas, and the low-temperature oxygen-rich mixed gas is input into the compressor set;

[0015] S2, compression and condensation: the low-temperature oxygen-rich mixed gas is compressed and heated in the compressor set, and then input into the compressor outlet heat exchanger for heat exchange and cooling; the cooled gas is input into the gas-liquid separation tank for gas-liquid separation, so as to obtain high-pressure low-temperature oxygen-rich mixed gas;

[0016] S3, temperature swing adsorption isobaric drying and pressure swing adsorption purification: the high-pressure low-temperature oxygen-rich mixed gas is equally divided into two streams, one of which is input into the temperature swing adsorption isobaric drying mechanism for drying, so as to remove excess water and obtain low-dew-point oxygen-rich flue gas; the other of which is input into the pressure swing adsorption purification mechanism for removing excess water, carbon dioxide and nitrogen, so as to obtain low-dew-point high-purity oxygen gas; the low-dew-point oxygen-rich flue gas and the low-dew-point high-purity oxygen gas are mixed and input into the dust removal and filtration mechanism;

[0017] S4, the mixed gas of the low-dew-point oxygen-rich flue gas and the low-dew-point high-purity oxygen gas is output as product gas after dust removal and filtration by the dust removal and filtration mechanism.

[0018] Further, the temperature swing adsorption isobaric drying of the step S3 comprises the following steps:

[0019] A1, hot blowing: a part of the high-pressure low-temperature oxygen-rich mixed gas is sequentially treated by the pre-drying tower and the heater from the drying gas inlet pipe, so as to heat the gas temperature to 150-170 DEG C; the heated gas is input into the second adsorption tower for hot blowing; after the hot blowing, the gas is sequentially cooled and separated from liquid water by the condenser and the gas-liquid separator; finally, the gas is input into the drying gas inlet pipe and transported to the first adsorption tower for adsorption; the gas is output from the drying product gas main pipe after the adsorption by the first adsorption tower;

[0020] A2, cold blowing: a part of the high-pressure low-temperature oxygen-enriched gas mixture from the drying inlet pipe is sequentially subjected to cold blowing through the second adsorption tower, then is delivered to the heater to be heated to 150-170°C, and then is input into the pre-drying tower for heating and regeneration treatment, after the treatment, is sequentially cooled and separated from liquid water through the condenser and the gas-liquid separator, and finally is input into the drying product gas main pipe to be delivered to the first adsorption tower for adsorption, and the gas after being adsorbed through the first adsorption tower is output from the drying product gas main pipe;

[0021] A3, exchange the working of the first adsorption tower and the second adsorption tower, so that the first adsorption tower is sequentially subjected to hot blowing and cold blowing, and the second adsorption tower is subjected to adsorption, and the other after adsorption is output from the drying product gas main pipe;

[0022] A4, repeat steps A1-A3 to realize continuous drying of the high-pressure low-temperature oxygen-enriched gas mixture.

[0023] Further, the pressure swing adsorption purification of step S3 comprises the following steps:

[0024] B1, adsorption: the high-pressure low-temperature oxygen-enriched gas mixture is input from the bottom to the top of the pressure swing adsorption tower from the pressure swing adsorption inlet pipe, after being adsorbed through the pressure swing adsorption tower, the product gas is input into the pressure swing adsorption product gas pipe from the top of the pressure swing adsorption tower through the pressure swing adsorption output pipe, and finally is input into the dust removal and filtration mechanism;

[0025] B2, pressure equalization and pressure reduction: the high-pressure gas in the pressure swing adsorption tower after adsorption is input into another pressure swing adsorption tower through the pressure equalization mechanism to balance the gas pressure of the two towers;

[0026] B3, reverse discharge: the gas in the pressure swing adsorption tower after pressure equalization and pressure reduction is input into the first water washing tower through the pressure swing adsorption recovery pipe against the adsorption direction to recover, and the gas pressure in the pressure swing adsorption tower is reduced to normal pressure;

[0027] B4, vacuum pumping: the gas in the pressure swing adsorption tower after reverse discharge is pumped out through the vacuum pump against the adsorption direction and is discharged from the pressure swing adsorption exhaust pipe;

[0028] B5, pressure equalization and pressure increase: after the vacuum pumping is completed, the pressure swing adsorption tower receives the high-pressure gas output from the pressure swing adsorption tower of step B2 through the pressure equalization mechanism to balance the gas pressure of the two towers;

[0029] B6, final increase: the product gas is input into the pressure swing adsorption tower after pressure equalization and pressure increase through the pressure swing adsorption product gas pipe, the first regulating valve, the pressure equalization mechanism and the pressure swing adsorption output pipe in sequence, so that the gas pressure in the pressure swing adsorption tower (31) is uniformly increased to the adsorption pressure;

[0030] B7, repeat steps B1-B6 to realize continuous removal of water, carbon dioxide and nitrogen from the high-pressure low-temperature oxygen-enriched gas mixture in the pressure swing adsorption purification mechanism.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] (1) The present application has low oxygen recovery cost. 50% of the oxygen-enriched flue gas enters the temperature swing adsorption isobaric drying mechanism, and the remaining 50% of the oxygen-enriched flue gas enters the pressure swing adsorption purification mechanism. The product gas after processing of the two systems is mixed and sent to the dust removal and filtration system. This operation can use the pressure swing adsorption denitrification process to treat 50% of the oxygen-enriched flue gas, can remove nitrogen and water in the raw gas (oxygen-enriched flue gas), and does not rely on external nitrogen removal devices (which have low oxygen recovery rate). Therefore, if the pressure swing adsorption denitrification process is used for all the oxygen-enriched flue gas, the overall oxygen recovery rate of the system will be reduced. However, the pressure swing adsorption denitrification process is used for 50% of the oxygen-enriched flue gas, and the temperature swing adsorption isobaric drying process is used for the other 50% of the oxygen-enriched flue gas, and the gases after processing of the two processes are mixed, which can make the oxygen purity meet the demand (more than 98.5%) and effectively improve the oxygen recovery rate (about 8%).

[0033] (2) The present application can further improve the oxygen recovery rate (about 8%) by using the pressure swing adsorption denitrification process to treat 50% of the oxygen-enriched flue gas. This is because the pressure swing adsorption purification process can obtain oxygen with a purity of more than 99.2%. At the same time, the temperature swing adsorption isobaric drying process is used for the other 50% of the oxygen-enriched flue gas. Since the temperature swing adsorption mainly removes water in the oxygen-enriched flue gas, the process flow adopts isobaric drying, the regeneration gas uses a small part of the oxygen-enriched flue gas, and after regeneration, the high-temperature oxygen-enriched flue gas is cooled to separate liquid water and then returns to the temperature swing adsorption inlet to combine with most of the oxygen-enriched flue gas for drying. The whole process does not have vent gas. The regeneration gas only separates gaseous water in the oxygen-enriched flue gas into liquid water by warming to desorb water and cooling to liquefy water, so the yield is more than 99.9%. Therefore, the oxygen recovery rate is high. Finally, the product gases after the temperature swing adsorption isobaric drying process and the pressure swing adsorption purification process are mixed to obtain oxygen with a purity of more than 98.5%. At the same time, the temperature swing adsorption drying or pressure swing adsorption purification can be freely selected according to the components of the oxygen-enriched flue gas, which increases the flexibility of the device, improves the oxygen recovery rate, and significantly improves the economic benefits of enterprises.

[0034] (3) The present application has low recovery cost, advanced temperature swing adsorption drying process technology, and simple operation. Compared with the pressure swing adsorption purification, it has the characteristics of low construction investment, small occupied area, and high yield. By dividing the oxygen-enriched flue gas into two streams, one stream is subjected to temperature swing adsorption drying, and the other stream is subjected to pressure swing adsorption purification. The mixed product gas can obtain high-purity oxygen, which can make up for the high cost and low recovery rate of the pressure swing adsorption purification, and effectively reduce the cost of recovery.

[0035] (3) The application separates the moisture in the oxygen-enriched flue gas by the cooperation of the first adsorption tower, the second adsorption tower and the pre-drying tower, and relies on the condenser and the gas-liquid separator in the temperature swing adsorption drying process. The adsorbent bed is subjected to hot blowing, cold blowing and adsorption. The principle is that the moisture is adsorbed by the adsorbent in the first adsorption tower or the second adsorption tower at low temperature, and the adsorbed moisture is desorbed at high temperature. Therefore, when the adsorbent is saturated, the adsorbent bed is heated by hot blowing to desorb the adsorbed moisture, and the adsorbent is completely regenerated. After hot blowing, the temperature of the adsorbent bed is high, so the adsorption performance of the adsorbent is poor. Therefore, the temperature of the adsorbent bed is reduced to normal temperature by cold blowing, and then the adsorption state is converted. The whole process has no oxygen loss, and the water vapor generated by regeneration is separated from the gas after cooling.

[0036] (4) In the pressure swing adsorption purification process, the oxygen with a purity greater than 99.2% is obtained by the cooperation of the pressure equalizing pipeline and the pressure swing adsorption tower. In the reverse discharge process, the adsorbed impurities are desorbed from the adsorbent, and the reverse discharge gas containing part of oxygen is returned to the first water washing tower for further treatment, thereby increasing the oxygen recovery rate of the system, improving the use efficiency of the adsorbent, and reducing the system cost.

[0037] (5) The application adopts a dust removal and filtration mechanism to filter the product mixed gas after the temperature swing adsorption and isobaric drying treatment and the pressure swing adsorption purification treatment, and the final product gas obtained is subjected to dust removal by the dust removal and filtration system, so that the product oxygen gas with a dust content of ≤1 μm is obtained, the quality of the product oxygen gas is effectively improved, and the application range of the product oxygen gas is widened.

[0038] (6) The application removes the dust particles in the mixed gas by the water washing mechanism. The first water washing tower is used for water washing and temperature reduction to remove the dust particles in the mixed gas, so as to avoid the corrosion and wear of the equipment and pipeline caused by the deposition of the low-temperature water particles in the later stage. The second water washing tower is used for low-temperature water washing and temperature reduction to reduce the water vapor content of the oxygen-enriched flue gas, reduce the volume flow of the oxygen-enriched flue gas, and reduce the energy consumption of the compression work in the later stage. No condensate is generated in the compression process, so the wear of the oxygen compressor in the compression process is reduced. After compression, low-temperature condensation is used to reduce the water removal load of the temperature swing and pressure swing adsorption in the later stage, and the total energy consumption of the system is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The system flowchart of the application.

[0040] Figure 2 The connection structure diagram of the temperature swing adsorption and isobaric drying mechanism of the application.

[0041] Figure 3 The connection structure diagram of the pressure swing adsorption purification mechanism of the application.

[0042] Figure 4 This is a connection structure diagram of the pressure swing adsorption purification mechanism in Embodiment 3 of the present invention.

[0043] The names corresponding to the reference numerals in the attached figures are as follows:

[0044] 1-Compressor unit, 2-Compressor outlet heat exchanger, 3-Gas-liquid separator, 4-Dust removal and filtration mechanism, 5-Flue gas inlet pipe, 6-Ambient temperature water pipe, 7-First water washing tower, 8-Drain pipe, 9-Second water washing tower, 10-Outlet pipe, 11-Drying inlet pipe, 12-First gas delivery pipe, 13-Second gas delivery pipe, 14-Third gas delivery pipe, 15-Fourth gas delivery pipe, 16-First adsorption tower, 17-Second adsorption tower, 18-First output pipe, 19-Second output pipe, 20-Dried product gas pipe, 21-Pre-drying tower, 22-Heater, 23-Fifth gas delivery pipe, 24-Condenser, 25-Gas-liquid separator, 2 6-Sixth gas supply pipe, 27-Seventh gas supply pipe, 28-First on / off valve, 29-Second on / off valve, 30-Pressure swing adsorption (PSA) inlet pipe, 31-Pressure swing adsorption (PSA) tower, 32-Pressure swing adsorption (PSA) outlet gas pipe, 33-Pressure swing adsorption (PSA) product gas pipe, 34-First regulating valve, 35-Pressure swing adsorption (PSA) exhaust pipe, 36-Pressure swing adsorption (PSA) recovery pipe, 37-Third on / off valve, 38-Pressure regulating valve, 39-Recovery regulating valve, 40-Vacuum pump, 41-Equalizing pipe, 42-Equalizing switching valve, 43-Chiller unit, 44-Low temperature heat exchanger, 45-Switch adsorption isobaric drying mechanism, 46-Pressure swing adsorption (PSA) purification mechanism, 47-Dust removal and filtration system. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0046] Example 1

[0047] like Figures 1-3 As shown, the energy-saving system for purifying and recycling oxygen from high-temperature oxygen-enriched flue gas includes a water washing mechanism, a compressor unit 1, a compressor outlet heat exchanger 2, a gas-liquid separator 3, a temperature swing adsorption isobaric drying mechanism 45, a pressure swing adsorption purification mechanism 46, a dust removal and filtration mechanism 4, and a cooling mechanism, etc.

[0048] The water washing mechanism is used for removing dust particles in mixed gas, which comprises a flue gas inlet pipe 5, a normal temperature water pipe 6, a first water washing tower 7, a drain pipe 8, a second water washing tower 9 and an outlet pipe 10. The flue gas inlet pipe 5 is used for connecting the external high-temperature oxygen-enriched flue gas, which is connected with the first water washing tower 7. The normal temperature water pipe 6 is connected with the water inlet of the first water washing tower 7, and is used for filling the normal temperature water into the first water washing tower 7, so that there is enough normal temperature water in the first water washing tower 7 to reduce the temperature of the high-temperature oxygen-enriched flue gas. The first water washing tower 7 is filled with structured packing, which is used for removing the dust particles in the mixed gas, avoiding the corrosion and wear of the equipment and pipeline caused by the deposition of the low-temperature water particles in the later stage, and reducing the temperature of the high-temperature oxygen-enriched flue gas by the normal temperature water. The inlet of the first water washing tower 7 is connected with the pressure swing adsorption recovery pipe 36, which is used for reprocessing the flue gas recovered by the pressure swing adsorption purification. The drain pipe 8 is connected with the bottom water outlet, and is used for draining the used normal temperature water. The inlet of the second water washing tower 9 is connected with the outlet of the first water washing tower 7, which is used for reducing the water vapor content of the low-temperature oxygen-enriched flue gas treated by the first water washing tower 7, reducing the oxygen-enriched flue gas volume flow, and reducing the energy consumption of the compression work in the later stage. The water inlet and the water outlet of the second water washing tower 9 are connected with the hot side water outlet and the hot side water inlet of the low-temperature heat exchanger 44 through pipes, respectively, which are used for connecting and outputting the heat exchange water in the low-temperature heat exchanger 44, and inputting the oxygen-enriched flue gas treated by the secondary water washing into the outlet pipe 10. One end of the outlet pipe 10 is connected with the outlet of the second water washing tower 9, and the other end is connected with the inlet of the compressor set 1, which is used for outputting the oxygen-enriched flue gas to the compressor set 1 for processing.

[0049] The compressor set 1 is used for compressing the oxygen-enriched flue gas and delivering it to the compressor outlet heat exchanger 2.

[0050] The compressor outlet heat exchanger 2 is used for heat exchange of the oxygen-enriched flue gas. The hot side outlet of the compressor outlet heat exchanger 2 is connected with the inlet of the gas-liquid separation tank 3 through a pipe. The water outlet and the water inlet of the compressor outlet heat exchanger 2 are connected with the water inlet and the water outlet of the cold water unit 43 through pipes, respectively.

[0051] The gas-liquid separation tank 3 is connected with the heat-exchanged oxygen-enriched flue gas, separates the water in the oxygen-enriched flue gas, and improves the purity of the oxygen-enriched flue gas. The exhaust port of the gas-liquid separation tank 3 is connected with the drying inlet pipe 11 and the pressure swing adsorption inlet pipe 30 through pipes, which are used for inputting the separated oxygen-enriched flue gas into the variable temperature adsorption constant pressure drying mechanism 45 and the pressure swing adsorption purification mechanism 46 for processing.

[0052] The temperature swing adsorption isobaric drying mechanism 45 includes a drying inlet gas pipe 11, a first gas conveying pipe 12, a second gas conveying pipe 13, a third gas conveying pipe 14, a fourth gas conveying pipe 15, a first adsorption tower 16, a second adsorption tower 17, a first output pipe 18, a second output pipe 19, a dried product gas pipe 20, a pre-drying tower 21, a heater 22, a fifth gas conveying pipe 23, a condenser 24, a gas-liquid separator 25, a sixth gas conveying pipe 26, a seventh gas conveying pipe 27, a first on-off valve 28 and a second on-off valve 29.The drying inlet pipe 11 is connected with the exhaust port of the gas-liquid separation tank 3, and is used for connecting the oxygen-enriched flue gas to be treated. The first gas conveying pipe 12 is connected with the drying inlet pipe 11 at one end and is connected with the first adsorption tower 16 at the other end, and is used for conveying the gas. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the first gas conveying pipe 12. The second gas conveying pipe 13 is connected with the drying inlet pipe 11 at one end and is connected with the second adsorption tower 17 at the other end, and is used for conveying the gas. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the second gas conveying pipe 13. The third gas conveying pipe 14 is connected with the drying inlet pipe 11 at one end and is connected with the pre-drying tower 21 at the other end, and is used for conveying the gas. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the third gas conveying pipe 14. The fourth gas conveying pipe 15 is connected with the third gas conveying pipe 14 and is connected with the condenser 24. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the fourth gas conveying pipe 15. The first adsorption tower 16 and the second adsorption tower 17 are used for adsorbing the gas. The first output pipe 18 is connected with the bottom of the first adsorption tower 16, and is used for outputting the adsorbed gas to the drying product gas main pipe 20. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the first output pipe 18. The second output pipe 19 is connected with the bottom of the second adsorption tower 17, and is used for outputting the adsorbed gas to the drying product gas main pipe 20. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the second output pipe 19. The drying product gas pipe 20 is connected with the pressure swing adsorption output gas pipe 32, so that the gas dried by the pressure swing adsorption and the gas purified by the pressure swing adsorption are mixed and then input into the dust removal and filtration mechanism 4 for dust removal and filtration. The pre-drying tower 21 is used for drying the gas again to remove the water in the gas. The pre-drying tower 21 is connected with the heater 22. The heater 22 is used for heating the gas to 150-170 DEG C. The heater 22 is connected with the fifth gas conveying pipe 23 and the pre-drying tower 21 at two ends, and is used for outputting the gas. The fifth gas conveying pipe 23 is connected with the first output pipe 18 and the second output pipe 19 through pipelines, and is used for conveying the gas. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the connecting pipeline of the fifth gas conveying pipe 23 and the first output pipe 18. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the connecting pipeline of the fifth gas conveying pipe 23 and the second output pipe 19. The condenser 24 is connected with the fourth gas conveying pipe 15 at one end and is connected with the gas-liquid separator 25 at the other end. The condenser 24 is used for condensing the gas and sending the gas to the gas-liquid separator 25 to separate the water again, so as to ensure the purity of the gas. The gas-liquid separator 25 is used for separating the water in the gas, and conveying the separated gas back to the drying inlet pipe 11 for reprocessing. The separated condensed water is discharged from the system. The sixth gas conveying pipe 26 is connected between the third gas conveying pipe 14 and the fourth gas conveying pipe 15. The seventh gas conveying pipe 27 is connected with the sixth gas conveying pipe 26 at one end and is connected with the first gas conveying pipe 12 and the second gas conveying pipe 13 through pipelines at the other end. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the connecting pipeline of the seventh gas conveying pipe 27 and the first gas conveying pipe 12. The first on-off valve 28 for controlling the opening and closing of the pipeline is installed on the connecting pipeline of the seventh gas conveying pipe 27 and the second gas conveying pipe 13. The first on-off valve 28 is used for controlling the opening and closing of the pipeline, and the number of the first on-off valve 28 is multiple. The second on-off valve 29 is used for controlling the opening and closing of the pipeline, and the number of the second on-off valve 29 is two. The second on-off valve 29 is installed on both sides of the seventh gas conveying pipe 27.

[0053] The pressure swing adsorption purification mechanism 46 includes a pressure swing adsorption gas inlet pipe 30, a pressure swing adsorption tower 31, a pressure swing adsorption gas outlet pipe 32, a pressure swing adsorption product gas pipe 33, a pressure equalization mechanism, a pressure swing adsorption exhaust pipe 35, a pressure swing adsorption recovery pipe 36, a third on-off valve 37, a pressure regulating valve 38, a dust removal and filtration system 47, a recovery regulating valve 39, and a vacuum pump 40. The pressure swing adsorption gas inlet pipe 30 is connected to the exhaust port of the gas-liquid separation tank 3, and is connected to the bottom of each pressure swing adsorption tower 31 through a pipeline. The third on-off valve 37 is installed on the pipeline connecting each pressure swing adsorption tower 31. There are multiple pressure swing adsorption towers 31, and at least three pressure swing adsorption towers 31. One end of each pressure swing adsorption tower 31 is connected to the pressure swing adsorption gas inlet pipe 30 through a pipeline, and the other end is connected to the pressure swing adsorption gas outlet pipe 32 through a pipeline. The pressure swing adsorption gas outlet pipe 32 is used to output the adsorbed gas to the pressure swing adsorption product gas pipe 33. The pressure swing adsorption product gas pipe 33 is connected to the dust removal and filtration mechanism 4. The pressure equalization mechanism is used to equalize the pressure of each pressure swing adsorption tower 31, and includes at least two pressure equalization pipes 41. Each pressure equalization pipe 41 is not connected to each other, and is connected to each pressure swing adsorption tower 31 through a pipeline. The pressure equalization switch valve 42 is installed on the pipeline connecting the pressure equalization pipe 41 and each pressure swing adsorption tower 31. The pressure swing adsorption exhaust pipe 35 is connected to the pipeline of each pressure swing adsorption tower 31 through a pipeline. The third on-off valve 37 is installed on the pipeline connecting each pressure swing adsorption tower 31, and controls the opening and closing of the pipeline. The vacuum pump 35 is installed on the pressure swing adsorption exhaust pipe 35, and is used to output the exhaust gas. The pressure swing adsorption recovery pipe 36 is connected to the pipeline of each pressure swing adsorption tower 31 through a pipeline. The third on-off valve 37 is installed on the pipeline connecting each pressure swing adsorption tower 31, and controls the opening and closing of the pipeline. The recovery regulating valve 39 is installed on the pressure swing adsorption recovery pipe 36, and is used to control the opening and closing of the pipeline. The other end of the pressure swing adsorption recovery pipe 36 is connected to the gas inlet port of the first water washing tower 7. The pressure regulating valve 38 is installed on the pressure swing adsorption product gas pipe 33, and is used to stabilize the gas pressure. The dust removal and filtration system 47 is installed on the pressure swing adsorption product gas pipe 33, and is used to filter the product gas, and further ensure the purity of the output gas.

[0054] The dust removal and filtration mechanism 4 is connected to the pressure swing adsorption product gas pipe 33, and is used to make the product oxygen gas enter the dust removal and filtration system 47, so that the dust content of the product oxygen gas is ≤1 μm. The final product oxygen gas is output through a pipeline for recycling.

[0055] Example 2

[0056] As shown in Figures 1-3 , the process of the energy-saving system for purifying oxygen from high-temperature oxygen-rich flue gas and recycling the oxygen includes the following steps:

[0057] S1, water washing: The high-temperature oxygen-rich flue gas (80℃, oxygen concentration 95-96%, water content 1-2%, carbon dioxide content 100ppm, nitrogen+argon content 2%) gas volume is 16000Nm3 / h and 30 m 3 / h and 30 m 3 / h and 30 m

[0058] The washing water of the first water washing tower 7 is subjected to first closed loop circulation, and the first closed loop circulation is specifically as follows: 32°C normal temperature water from outside the region enters the first water washing tower 7 through the normal temperature water pipe 6, in the first water washing tower 7, the washing water is subjected to normal temperature contact washing heat exchange with 80°C oxygen-enriched flue gas by the action of the structured packing, and the washing water after the washing heat exchange is returned to the water by the drain pipe 8.

[0059] The 7°C washing water of the second water washing tower 9 is subjected to second closed loop circulation, and the second closed loop circulation is specifically as follows: the washing water of the second water washing tower 9 is returned to the water through the pipeline and enters the low-temperature heat exchanger 44 on the hot side, low-temperature water obtained by heat exchange is returned to the second water washing tower 9 through the pipeline, in the second water washing tower 9, the 7°C washing water is subjected to low-temperature contact heat exchange with the oxygen-enriched mixed gas discharged from the first water washing tower 7 by the action of the structured packing, and the washing water after the low-temperature heat exchange is transported to the low-temperature heat exchanger 44 on the hot side through the pipeline.

[0060] In this step, the cold side of the low-temperature heat exchanger G2 is subjected to first cold side closed loop circulation, and the first cold side closed loop circulation is specifically as follows: low-temperature water prepared by the water chilling unit 43 enters the low-temperature heat exchanger 44 on the cold side through the pipeline, and medium-temperature water obtained by heat exchange is returned to the inlet of the water chilling unit 43 through the pipeline.

[0061] S2, compression and condensation: the oxygen-enriched mixed gas with a temperature lower than 12°C obtained after washing and cooling enters the compressor set 1 through the gas outlet pipeline 10 to obtain 0.4 MPa·G oxygen-enriched mixed gas, the 0.4 MPa·G oxygen-enriched mixed gas enters the compressor outlet heat exchanger 2 on the hot side and is subjected to wall heat exchange with 5°C low-temperature water on the cold side to obtain oxygen-enriched mixed gas with a temperature lower than 15°C and condensate water, the 0.4 MPa·G, 15°C oxygen-enriched mixed gas and the condensate water enter the gas-liquid separation tank 3 through the pipeline to be subjected to gas-liquid separation, the condensate water is discharged from the bottom water outlet of the gas-liquid separation tank 3 through the pipeline, and the 0.4 MP·G, 15°C oxygen-enriched mixed gas is output from the top of the gas-liquid separation tank 3 to the dry gas inlet pipeline 11 and the pressure swing adsorption gas inlet pipeline 30.

[0062] The cold side water of the compressor outlet heat exchanger 2 carries out a second cold side closed loop circulation, and the second cold side closed loop circulation is specifically that the low-temperature water prepared by the water chiller 43 enters the cold side of the compressor outlet heat exchanger 2 through a pipeline, and the medium-temperature water obtained through heat exchange is returned to the inlet of the water chiller 43 through a pipeline.

[0063] S3, temperature swing adsorption and isobaric drying and pressure swing adsorption purification: in this step, a parallel process of temperature swing adsorption and isobaric drying and pressure swing adsorption purification is adopted, the high-pressure low-temperature oxygen-rich mixed gas is equally divided into two gas sources, one of which enters the temperature swing adsorption and isobaric drying mechanism 45 to remove excess water to obtain low-dew-point oxygen-rich flue gas, and the low-dew-point oxygen-rich flue gas is output through the dry product gas main pipe 20; the other enters the pressure swing adsorption purification mechanism 46 to remove excess water, carbon dioxide and nitrogen to obtain low-dew-point high-purity oxygen, and the low-dew-point high-purity oxygen is output through the pressure swing adsorption product gas pipe 33, the low-dew-point oxygen-rich flue gas output through the dry product gas main pipe 20 is input into the pressure swing adsorption product gas pipe 33, and after being mixed with the low-dew-point high-purity oxygen output through the pressure swing adsorption product gas pipe 33, the purity of the final product oxygen is greater than 98.5%, and the mixed gas is input into the dust removal and filtration mechanism 4.

[0064] S4, dust removal and filtration, product oxygen with a purity greater than 98.5% enters the dust removal and filtration mechanism 4, so that the dust content of the product oxygen is ≤1 μm, and the final product oxygen is output through the pipeline P9 for recycling.

[0065] The cycle timing of the temperature swing adsorption and isobaric drying mechanism 45 is shown in Table 1, and the specific working steps are as follows:

[0066] Step A1, adsorption in the first adsorption tower 16 and hot blowing in the second adsorption tower 17: part of the oxygen-rich mixed gas is transported from the dry gas inlet pipe 11 to the first adsorption tower 16 through the first on-off valve 28, and the water in the oxygen-rich mixed gas is adsorbed and dehydrated in the first adsorption tower 16, and the dried gas is sequentially output to the pressure swing adsorption product gas pipe 33 through the first output pipe 18 and the dry product gas main pipe 20; another part of the oxygen-rich mixed gas is transported to the pre-drying tower 21 through the third gas inlet pipe 14 for pre-drying, and then heated to 150-170℃ through the heater 22, and then enters the second adsorption tower 17 from the fifth gas inlet pipe 23 to perform hot blowing on the second adsorption tower 17, and the hot blowing lasts for 4h, and the mixed gas after hot blowing enters the condenser 24 through the seventh gas inlet pipe 27, the sixth gas inlet pipe 26 and the fourth gas inlet pipe 15, and the water in the mixed gas is condensed in the condenser 24, and the water is discharged out of the system through the gas-liquid separator 25, and the remaining mixed gas returns to the dry gas inlet pipe 11 from the top of the gas-liquid separator 25;

[0067] Step A2, adsorption of the first adsorption tower 16, the second adsorption tower 17 cold blow: a part of the oxygen-enriched gas from the dry gas inlet pipe 11 through the first on-off valve 28 to the first adsorption tower 16, the water in the oxygen-enriched gas is adsorbed and dried in the first adsorption tower 16, and the dried gas is output to the pressure swing adsorption product gas pipe 33 through the first output pipe 18 and the dry product gas main pipe 20 in turn; another part of the oxygen-enriched gas is input into the second gas inlet pipe 13 through the third gas inlet pipe 14, the sixth gas inlet pipe 26 and the seventh gas inlet pipe 27 in turn, and finally enters the second adsorption tower 17 to perform cold blowing on the second adsorption tower 17, and the cold blowing lasts for 1-4h; the mixed gas after cold blowing enters the heater 22 through the second output pipe 19 and the fifth gas inlet pipe 23 in turn, and the mixed gas after heating enters the pre-drying tower 21, and then the pre-drying tower 21 is heated and blown; the mixed gas after hot blowing enters the condenser 24 through the third gas inlet pipe 14 and the fourth gas inlet pipe 15, and the mixed gas is condensed in the condenser 24 to remove water, and the remaining mixed gas returns to the dry gas inlet pipe 11 from the top of the gas-liquid separator 25;

[0068] Step A3, adsorption of the second adsorption tower 17, hot blowing of the first adsorption tower 16: a part of the oxygen-enriched gas from the dry gas inlet pipe 11 is transported to the second adsorption tower 17 through the second gas inlet pipe 13, and the water in the oxygen-enriched gas is adsorbed and dried in the second adsorption tower 17, and the dried gas is output to the pressure swing adsorption product gas pipe 33 through the second output pipe 19 and the dry product gas main pipe 20; another part of the oxygen-enriched gas is transported to the pre-drying tower 21 through the third gas inlet pipe 14 for pre-drying, and then heated to 150-170℃ through the heater 22, and then enters the first adsorption tower 16 through the fifth gas inlet pipe 23 and the first output pipe 18 in turn to perform hot blowing on the first adsorption tower 16, and the hot blowing lasts for 4h; the mixed gas after hot blowing enters the condenser 24 through the seventh gas inlet pipe 27, the sixth gas inlet pipe 26 and the fourth gas inlet pipe 15 in turn, and the mixed gas is condensed in the condenser 24 to remove water, and the remaining mixed gas returns to the dry gas inlet pipe 11 from the top of the gas-liquid separator 25;

[0069] Step A4, the second adsorption tower 17 adsorption, the first adsorption tower 16 cold blow: a part of the oxygen-rich mixture from the dry gas inlet pipe 11 through the second gas pipe 13 to the second adsorption tower 17, the water in the oxygen-rich mixture is adsorbed and dried in the second adsorption tower 17, and the dried gas is output to the pressure swing adsorption product gas pipe 33 through the second output pipe 19, the dry product gas main pipe 20; another part of the oxygen-rich mixture is input into the first adsorption tower 16 through the third gas pipe 14, the sixth gas pipe 26, the sixth gas pipe 26, and the seventh gas pipe 27 in sequence, and the first adsorption tower 16 is cold blown, and the cold blowing lasts for 1-4 hours; the mixed gas after cold blowing enters the heater 22 through the first output pipe 18 and the fifth output pipe 23 in sequence, and the mixed gas after heating enters the pre-drying tower 21, and the pre-drying tower 21 is then hot blown; the mixed gas after hot blowing enters the condenser 24 through the third gas pipe 14 and the fourth gas pipe 15 in sequence, and the mixed gas is condensed in the condenser 24 to output water, and the remaining mixed gas returns to the dry gas inlet pipe 11 from the top of the gas-liquid separator 25.

[0070] Step A5, repeating steps A1-A4 to realize continuous drying of the high-pressure low-temperature oxygen-rich mixture to obtain a mixed gas with a dew point lower than-47℃ and a water content lower than 50ppm.

[0071] Table 1

[0072]

[0073] The cycle timing of the pressure swing adsorption purification mechanism 46 is shown in Table 2, and the specific working steps are as follows:

[0074] The pressure swing adsorption tower 31 has six (FT1, FT2, FT3, FT4, FT5, FT6), and the whole process step sequence process of the main flow is described by taking one pressure swing adsorption tower 31 (FT1) as an example, and the process of the remaining pressure swing adsorption towers 31 is completely the same.

[0075] Step B1, adsorption: the high pressure and low temperature oxygen-rich gas delivered from the pressure swing adsorption inlet pipe 30 enters the pressure swing adsorption tower 31 (FT1) through the pipeline, in which the water, carbon dioxide and nitrogen impurities are sequentially and selectively adsorbed by the multiple adsorbents filled in the pressure swing adsorption tower 31, and the product oxygen with carbon dioxide content lower than 50 ppm, water content lower than 50 ppm and oxygen content higher than 99% is discharged through the pressure swing adsorption outlet pipe 32. Most of the product oxygen is sent to the dust removal filtering mechanism 4 through the pressure swing adsorption product gas pipe 33 after being stabilized by the pressure regulating valve 38 to filter the dust of the adsorbent and control the dust content in the product oxygen to be lower than 1 μm. A small amount of product oxygen is used for the final pressure increase of the remaining pressure swing adsorption towers 31 through the first regulating valve 34. With the adsorption, when the front of the impurities (i.e. the adsorption front) rises to a certain height close to the outlet of the adsorption bed, the third on-off valve 37 installed on the pipeline connecting the pressure swing adsorption inlet pipe 30 and the third on-off valve 37 installed on the pressure swing adsorption outlet pipe 32 are closed to stop the adsorption. At this time, there is still a section of saturated adsorbent between the adsorption front and the outlet of the adsorption bed, which is called the reserved section.

[0076] Step B2, one equalization pressure reduction: after the adsorption process is completed, the equalization switch valve 42 installed on the pipeline connecting one equalization pipe 41 and the pressure swing adsorption outlet pipe 32 and the equalization switch valve 42 installed on the pipeline connecting the other equalization pipe 41 and the pressure swing adsorption outlet pipe 32 are opened, and the product oxygen with higher pressure in the pressure swing adsorption tower 31 (FT1) is discharged into the pressure swing adsorption tower 31 (FT4) through the equalization pipe 41 until the pressures of the two pressure swing adsorption towers 31 are basically equal. This process is not only a pressure reduction process, but also recovers the oxygen in the dead space of the adsorption completed pressure swing adsorption tower 31. In this process, the adsorption front of the pressure swing adsorption tower 31 (FT1) will continue to move forward, but still not reach the outlet.

[0077] Step B3, two equalization pressure reduction: after the one equalization pressure reduction process is completed, the equalization switch valve 42 installed on the pipeline connecting the other equalization pipe 41 and the pressure swing adsorption outlet pipe 32 and the equalization switch valve 42 installed on the pipeline connecting the other equalization pipe 41 and the pressure swing adsorption outlet pipe 32 are opened, and the product oxygen with higher pressure in the pressure swing adsorption tower 31 (FT1) is discharged into the pressure swing adsorption tower 31 (FT5) through the equalization pipe 41 for the two equalization pressure increase of the pressure swing adsorption tower 31. This process continues to recover the oxygen in the dead space of the pressure swing adsorption tower 31 (FT1), and at the same time, the adsorption front of the adsorption completed pressure swing adsorption tower 31 will also continue to move forward, but still not reach the outlet.

[0078] Step B4, reverse: after the continuous forward pressure reduction process is completed, the adsorption front of the pressure swing adsorption column 31 (FT1) has reached the bed outlet basically; at this time, the three-way stop valve 37 installed on the connecting pipeline between the pressure swing adsorption recovery pipe 36 and the pressure swing adsorption column 31 (FT1) is opened, and the pressure in the pressure swing adsorption column 31 (FT1) is reduced to near atmospheric pressure in the reverse adsorption direction, at which time the adsorbed water, carbon dioxide and nitrogen and other impurities begin to desorb from the adsorbent; the reverse desorption gas returns to the inlet of the first water washing tower 7 through the recovery regulating valve 39;

[0079] Step B5, vacuum: after the reverse process is completed, the third-way stop valve 37 connecting the pressure swing adsorption column 31 (FT1) and the pressure swing adsorption exhaust pipe 35 is opened, and the pressure swing adsorption column 31 (FT1) is vacuumed, at which time a large amount of adsorbed impurities are desorbed and discharged to the local high point through the vacuum pump 40 in the reverse adsorption direction;

[0080] Step B6, two equalization pressure rising: after the vacuuming process is completed, the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) is opened, and the equalization switch valve 42 is opened, and the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT4) is opened, and the equalization switch valve 42 is opened, and the higher pressure oxygen in the pressure swing adsorption column 31 (FT4) is used to rise the pressure of the pressure swing adsorption column 31 (FT1) by two equalization pressure rising;

[0081] Step B7, one equalization pressure rising: after the two equalization pressure rising process is completed, the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) is opened, and the equalization switch valve 42 is opened, and the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT5) is opened, and the equalization switch valve 42 is opened, and the higher pressure oxygen in the pressure swing adsorption column 31 (FT5) is recovered into the pressure swing adsorption column 31 (FT1) which has just completed the two equalization pressure rising;

[0082] Step B8, final rising: after the two equalization pressure rising processes, the pressure in the pressure swing adsorption column 31 (FT1) still does not reach the adsorption pressure, at which time the equalization switch valve 42 connecting the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) and the first regulating valve 34 is opened, and the product oxygen is slowly raised to the pressure in the pressure swing adsorption column 31 (FT1) through the first regulating valve 34, until the pressure in the pressure swing adsorption column 31 (FT1) rises to the adsorption pressure.

[0083] After the above series of pressure reduction and pressure rising processes, the pressure swing adsorption column 31 (FT1) has completed the entire regeneration process, and is ready for the next adsorption and enters the next adsorption cycle.

[0084] The process step sequence of the adsorption columns FT2-6 is completely same as FT1. There is always one column in adsorption state, and five columns are in different regeneration states respectively, which ensures the continuous separation and purification of high-pressure and low-temperature oxygen-rich mixed gas.

[0085] Table 2

[0086]

[0087]

[0088] Example 3

[0089] As shown in Figure 1 , 2 , 4, the process of the energy-saving system for purifying oxygen from high-temperature oxygen-rich flue gas and recycling the oxygen includes the following steps:

[0090] S1, water washing: 16000 Nm3 / h of high-temperature oxygen-rich flue gas (80℃, oxygen concentration 95-96%, water content 1-2%, carbon dioxide content 100ppm, nitrogen+argon content 2%) and 30m 3 / h of 32℃ normal temperature water are respectively introduced into the first water washing tower 7 through the flue gas inlet pipe 5 and the normal temperature water pipe 6. Under the action of the structured packing, the normal temperature water is used as washing water to wash the high-temperature oxygen-rich flue gas to remove the particulate impurities in the high-temperature oxygen-rich flue gas, and at the same time, the high-temperature oxygen-rich flue gas is contacted with the washing water to exchange heat and obtain 35℃ oxygen-rich mixed gas. The washing water after heat exchange is returned to the water by gravity through the drain pipe 8, and the oxygen-rich mixed gas is introduced into the second water washing tower 9 through the gas path to be contacted with 33m 3 / h of 7℃ low-temperature water from the low-temperature heat exchanger 44 as low-temperature washing water to exchange heat and obtain oxygen-rich mixed gas with a temperature lower than 12℃. The oxygen-rich mixed gas with a temperature lower than 12℃ is output from the top of the second water washing tower 9 through the gas outlet pipe 10;

[0091] The washing water of the first water washing tower 7 is subjected to first closed loop circulation, and the first closed loop circulation is specifically as follows: 32℃ normal temperature water from outside the area is introduced into the first water washing tower 7 through the normal temperature water pipe 6. In the first water washing tower 7, the washing water is contacted with the 80℃ oxygen-rich flue gas to exchange heat at normal temperature under the action of the structured packing. The washing water after washing and heat exchange is returned to the water by gravity through the drain pipe 8;

[0092] The 7℃ washing water of the second water washing tower 9 is subjected to second closed loop circulation, and the second closed loop circulation is specifically as follows: the washing water of the second water washing tower 9 is returned to the water through the pipe and introduced into the hot side of the low-temperature heat exchanger 44 to exchange heat and obtain low-temperature water which is returned to the second water washing tower 9 through the pipe. In the second water washing tower 9, the 7℃ washing water is contacted with the oxygen-rich mixed gas discharged from the first water washing tower 7 to exchange heat at low temperature under the action of the structured packing. The washing water after low-temperature heat exchange is transported to the hot side of the low-temperature heat exchanger 44 through the pipe.

[0093] In this step, the cold side of the low-temperature heat exchanger 44 carries out the first cold side closed loop cycle, and the first cold side closed loop cycle is specifically: the low-temperature water prepared by the water chiller 43 enters the cold side of the low-temperature heat exchanger 44 through the pipeline, and the medium-temperature water obtained by heat exchange returns to the inlet of the water chiller 43 through the pipeline.

[0094] S2, compression and condensation: the oxygen-enriched mixed gas below 12℃ obtained after washing and cooling enters the compressor set 1 through the outlet pipeline 10 to be compressed to obtain 0.4MPa.G oxygen-enriched mixed gas, and the 0.4MPa.G oxygen-enriched mixed gas enters the heat exchanger 2 through the pipeline to carry out wall heat exchange with the 5℃ low-temperature water on the cold side to obtain oxygen-enriched mixed gas below 15℃ and condensate water, and the 0.4MPa.G, 15℃ oxygen-enriched mixed gas and the condensate water enter the gas-liquid separation tank 3 through the pipeline to be separated, the condensate water is discharged from the bottom outlet of the gas-liquid separation tank 3 through the pipeline to be recycled, and the 0.4MP.G, 15℃ oxygen-enriched mixed gas is output from the top of the gas-liquid separation tank 3 to the drying inlet pipeline 11 and the pressure swing adsorption inlet pipeline 30;

[0095] The water on the cold side of the compressor outlet heat exchanger 2 carries out the second cold side closed loop cycle, and the second cold side closed loop cycle is specifically: the low-temperature water prepared by the water chiller 43 enters the cold side of the compressor outlet heat exchanger 2 through the pipeline, and the medium-temperature water obtained by heat exchange returns to the inlet of the water chiller 43 through the pipeline.

[0096] S3, variable temperature adsorption and pressure swing adsorption drying and purification: this step adopts a parallel process of variable temperature adsorption and pressure swing adsorption drying and purification, and divides the high-pressure and low-temperature oxygen-enriched mixed gas into two gas sources, one of which enters the variable temperature adsorption and pressure swing adsorption drying mechanism 45 to remove excess water to obtain low-dew-point oxygen-enriched flue gas, and the other of which enters the variable temperature adsorption and pressure swing adsorption purification mechanism 46 to remove excess water, carbon dioxide and nitrogen to obtain low-dew-point high-purity oxygen, and the low-dew-point high-purity oxygen is output through the variable temperature adsorption product gas pipeline 33, and the low-dew-point oxygen-enriched flue gas output through the drying product gas main pipeline 20 is input into the variable temperature adsorption product gas pipeline 33, mixed with the low-dew-point high-purity oxygen output from the variable temperature adsorption product gas pipeline 33, so that the purity of the final product oxygen is greater than 98.5%, and the mixed gas is input into the dust removal and filtration mechanism 4.

[0097] S4, dust removal and filtration: the product oxygen with a purity greater than 98.5% enters the dust removal and filtration mechanism 4, so that the dust content of the product oxygen is ≤1μm, and the final product oxygen is output through the pipeline P9 for recycling.

[0098] The variable temperature adsorption and pressure swing adsorption drying mechanism 45 cycle timing is shown in Table 1, and the specific working steps are as follows:

[0099] Step A1, adsorption of first adsorption tower 16, hot blow of second adsorption tower 17: part of the oxygen-enriched mixed gas from the drying inlet gas pipe 11 is transported to the first adsorption tower 16 through the first on-off valve 28, and the water in the oxygen-enriched mixed gas is adsorbed and dried in the first adsorption tower 16; the dried gas is output to the pressure swing adsorption product gas pipe 33 through the first output pipe 18 and the drying product gas main pipe 20 in sequence; another part of the oxygen-enriched mixed gas is transported to the pre-drying tower 21 through the third gas pipe 14 for pre-drying, and then heated to 150-170 DEG C through the heater 22, and then enters the second adsorption tower 17 from the fifth gas pipe 23 to perform hot blow on the second adsorption tower 17, and the hot blow lasts for 4h; the mixed gas after the hot blow enters the condenser 24 through the seventh gas pipe 27, the sixth gas pipe 26 and the fourth gas pipe 15 in sequence, and the mixed gas is condensed in the condenser 24 to remove water, and the water is discharged from the system through the gas-liquid separator 25, and the remaining mixed gas returns to the drying inlet gas pipe 11 from the top of the gas-liquid separator 25;

[0100] Step A2, adsorption of first adsorption tower 16, cold blow of second adsorption tower 17: part of the oxygen-enriched mixed gas from the drying inlet gas pipe 11 is transported to the first adsorption tower 16 through the first on-off valve 28, and the water in the oxygen-enriched mixed gas is adsorbed and dried in the first adsorption tower 16; the dried gas is output to the pressure swing adsorption product gas pipe 33 through the first output pipe 18 and the drying product gas main pipe 20 in sequence; another part of the oxygen-enriched mixed gas is transported to the second gas pipe 13 through the third gas pipe 14, the sixth gas pipe 26 and the seventh gas pipe 27 in sequence, and finally enters the second adsorption tower 17 to perform cold blow on the second adsorption tower 17, and the cold blow lasts for 1-4h; the mixed gas after the cold blow enters the heater 22 through the second output pipe 19 and the fifth gas pipe 23 in sequence, and then enters the pre-drying tower 21 after being heated, and then performs hot blow on the pre-drying tower 21; the mixed gas after the hot blow enters the condenser 24 through the third gas pipe 14 and the fourth gas pipe 15 in sequence, and the mixed gas is condensed in the condenser 24 to remove water, and the water is discharged from the system through the gas-liquid separator 25, and the remaining mixed gas returns to the drying inlet gas pipe 11 from the top of the gas-liquid separator 25;

[0101] Step A3, adsorption of the second adsorption tower 17, hot blow of the first adsorption tower 16: part of the oxygen-enriched mixed gas is transported from the drying inlet gas pipe 11 to the second adsorption tower 17 through the second gas pipe 13, and the water in the oxygen-enriched mixed gas is adsorbed and dried in the second adsorption tower 17, and the dried gas is output to the pressure swing adsorption product gas pipe 33 through the second output pipe 19 and the drying product gas main pipe 20; another part of the oxygen-enriched mixed gas is transported to the pre-drying tower 21 for pre-drying, and then heated to 150-170℃ through the heater 22, and then enters the first adsorption tower 16 through the fifth gas pipe 23 and the first output pipe 18 in sequence, so as to perform hot blow on the first adsorption tower 16, and the hot blow lasts for 4h; the mixed gas after the hot blow enters the condenser 24 through the seventh gas pipe 27, the sixth gas pipe 26 and the fourth gas pipe 15 in sequence, and the water in the mixed gas is condensed in the condenser 24, and the water is discharged out of the system through the gas-liquid separator 25, and the remaining mixed gas returns to the drying inlet gas pipe 11 from the top of the gas-liquid separator 25;

[0102] Step A4, adsorption of the second adsorption tower 17, cold blow of the first adsorption tower 16: part of the oxygen-enriched mixed gas is transported from the drying inlet gas pipe 11 to the second adsorption tower 17 through the second gas pipe 13, and the water in the oxygen-enriched mixed gas is adsorbed and dried in the second adsorption tower 17, and the dried gas is output to the pressure swing adsorption product gas pipe 33 through the second output pipe 19 and the drying product gas main pipe 20; another part of the oxygen-enriched mixed gas enters the first adsorption tower 16 through the third gas pipe 14, the sixth gas pipe 26, the sixth gas pipe 26 and the seventh gas pipe 27 in sequence, so as to perform cold blow on the first adsorption tower 16, and the cold blow lasts for 1-4h; the mixed gas after the cold blow enters the heater 22 through the first output pipe 18 and the fifth output pipe 23 in sequence, and then enters the pre-drying tower 21 after being heated, and then performs hot blow on the pre-drying tower 21, and the mixed gas after the hot blow enters the condenser 24 through the third gas pipe 14 and the fourth gas pipe 15 in sequence, and the water in the mixed gas is condensed in the condenser 24, and the water is discharged out of the system through the gas-liquid separator 25, and the remaining mixed gas returns to the drying inlet gas pipe 11 from the top of the gas-liquid separator 25;

[0103] Step A5, repeating steps A1-A4 to realize continuous drying of the high-pressure low-temperature oxygen-enriched mixed gas, so that the dew point of the mixed gas is lower than-47℃, and the water content is lower than 50ppm.

[0104] The cycle timing of the pressure swing adsorption purification mechanism 46 is shown in Table 3, and the specific working steps are as follows:

[0105] The pressure swing adsorption tower 31 has a total of 8 (FT1, FT2, FT3, FT4, FT5, FT6, FT7, FT8), and the whole process step sequence process of the main flow is described by taking one pressure swing adsorption tower 31 (FT1) as an example, and the process of the remaining pressure swing adsorption towers 31 is completely the same; the equalizing mechanism includes three equalizing pipes 41.

[0106] Step B1, adsorption: the high pressure and low temperature oxygen-rich mixed gas delivered from the pressure swing adsorption inlet pipe 30 enters the pressure swing adsorption tower 31 (FT1) through the pipeline, wherein the water, carbon dioxide and nitrogen impurity components are sequentially and selectively adsorbed by the multiple adsorbents filled in the pressure swing adsorption tower 31, and the product oxygen with carbon dioxide content lower than 50 ppm, water content lower than 50 ppm and oxygen content higher than 99% is discharged through the pressure swing adsorption outlet pipe 32. Most of the product oxygen is sent into the dust removal filtering mechanism 4 through the pressure swing adsorption product gas pipe 33 after being stabilized by the pressure regulating valve 38 to filter the dust of the adsorbent, so that the dust content in the product oxygen is controlled to be lower than 1 μm, and a small amount of product oxygen is used for the final pressure increase of the remaining pressure swing adsorption towers 31 through the first regulating valve 34. With the adsorption, when the front of the impurities (i.e. the adsorption front) rises to a certain height close to the outlet of the adsorption bed, the third on-off valve 37 installed on the pipeline connected with the pressure swing adsorption inlet pipe 30 and the third on-off valve 37 installed on the pressure swing adsorption outlet pipe 32 are closed to stop the adsorption. At this time, there is still a section of saturated adsorbent which is not adsorbed between the adsorption front and the outlet of the adsorption bed, which is called the reserved section;

[0107] Step B2, one equalization pressure reduction: after the adsorption process is completed, the equalization switch valve 42 installed on the pipeline connected with the first equalization pipe 41 and the pressure swing adsorption outlet pipe 32 and the equalization switch valve 42 installed on the pipeline connected with the other equalization pipe 41 and the pressure swing adsorption outlet pipe 32 are opened, and the product oxygen with higher pressure in the pressure swing adsorption tower 31 (FT1) is discharged into the pressure swing adsorption tower 31 (FT4) through the equalization pipe 41 until the pressures of the two pressure swing adsorption towers 31 are basically equal. This process not only reduces the pressure, but also recovers the oxygen in the dead space of the adsorption bed of the pressure swing adsorption tower 31 after the adsorption is completed. In this process, the adsorption front of the pressure swing adsorption tower 31 (FT1) will continue to move forward, but still does not reach the outlet;

[0108] Step B3, two equalization pressure reduction: after the one equalization pressure reduction process is completed, the equalization switch valve 42 installed on the pipeline connected with the second equalization pipe 41 and the pressure swing adsorption outlet pipe 32 and the equalization switch valve 42 installed on the pipeline connected with the other equalization pipe 41 and the pressure swing adsorption outlet pipe 32 are opened, and the product oxygen with higher pressure in the pressure swing adsorption tower 31 (FT1) is discharged into the pressure swing adsorption tower 31 (FT5) through the equalization pipe 41 for the two equalization pressure increase of the pressure swing adsorption tower 31. This process continues to recover the oxygen in the dead space of the adsorption bed of the pressure swing adsorption tower 31 (FT1), and at the same time, the adsorption front of the pressure swing adsorption tower 31 after the adsorption is completed will also continue to move forward, but still does not reach the outlet;

[0109] Step B4, reverse: after the continuous forward pressure reduction process is completed, the adsorption front of the pressure swing adsorption column 31 (FT1) has reached the bed outlet basically; at this time, the three-way stop valve 37 installed on the connecting pipeline between the pressure swing adsorption recovery pipe 36 and the pressure swing adsorption column 31 (FT1) is opened, and the pressure in the pressure swing adsorption column 31 (FT1) is reduced to near atmospheric pressure in the reverse adsorption direction, at which time the adsorbed water, carbon dioxide and nitrogen and other impurities begin to desorb from the adsorbent; the reverse desorption gas returns to the inlet of the first water washing tower 7 through the recovery regulating valve 39;

[0110] Step B5, vacuum: after the reverse process is completed, the third-way stop valve 37 connecting the pressure swing adsorption column 31 (FT1) and the pressure swing adsorption exhaust pipe 35 is opened, and the pressure swing adsorption column 31 (FT1) is vacuumed, at which time a large amount of adsorbed impurities are desorbed and discharged to the local high point through the vacuum pump 40 in the reverse adsorption direction;

[0111] Step B6, two equalization pressure rising: after the vacuuming process is completed, the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) is opened, and the equalization switch valve 42 is opened, and the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT4) is opened, and the equalization switch valve 42 is opened, and the higher pressure oxygen in the pressure swing adsorption column 31 (FT4) is used to rise the pressure of the pressure swing adsorption column 31 (FT1) by two equalization pressure rising;

[0112] Step B7, one equalization pressure rising: after the two equalization pressure rising processes are completed, the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) is opened, and the equalization switch valve 42 is opened, and the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT5) is opened, and the equalization switch valve 42 is opened, and the higher pressure oxygen in the pressure swing adsorption column 31 (FT5) is recovered into the pressure swing adsorption column 31 (FT1) which has just completed the two equalization pressure rising;

[0113] Step B8, final rising: after the two equalization pressure rising processes are completed, the pressure in the pressure swing adsorption column 31 (FT1) still does not reach the adsorption pressure, at which time the equalization switch valve 42 connecting the equalization pressure pipe 41 connecting the pressure swing adsorption output gas pipe 32 of the pressure swing adsorption column 31 (FT1) and the first regulating valve 34 is opened, and the product oxygen is slowly raised to the pressure in the pressure swing adsorption column 31 (FT1) through the first regulating valve 34, until the pressure in the pressure swing adsorption column 31 (FT1) rises to the adsorption pressure.

[0114] After the above series of pressure reduction and pressure rising processes, the pressure swing adsorption column 31 (FT1) has completed the entire regeneration process, and is ready for the next adsorption and enters the next adsorption cycle.

[0115] The process step sequence of the adsorption towers FT2-FT6 is completely same as that of FT1. There is always one tower in adsorption state, and five towers are in different regeneration states respectively, which ensures the continuous separation and purification of the high-pressure low-temperature oxygen-rich mixed gas.

[0116] Table 3

[0117]

[0118] The above embodiment is only one of the preferred embodiments of the present application, and should not be used to limit the protection scope of the present application, but any modification or polishing without substantial meaning made within the main design idea and spirit of the present application, and which still solves the technical problems consistent with the present application, should be included in the protection scope of the present application.

Claims

1. An energy-saving system for recycling oxygen from high-temperature oxygen-rich flue gas, comprising a water washing mechanism connected to the high-temperature oxygen-rich flue gas, a compressor unit (1) connected to the water washing mechanism by a pipeline, a compressor outlet heat exchanger (2) connected to the compressor unit (1) by a pipeline, and a gas-liquid separation tank (3) connected to the compressor outlet heat exchanger (2) by a pipeline, characterized in that, The device comprises a temperature swing adsorption and isobaric drying mechanism (45) and a pressure swing adsorption and purifying mechanism (46) connected with the gas-liquid separation tank (3), a dust removal and filtering mechanism (4) for processing the gas after the temperature swing adsorption and isobaric drying mechanism (45) and the pressure swing adsorption and purifying mechanism (46), and a cooling mechanism for cooling the water washing mechanism and the compressor outlet heat exchanger (2), wherein the output end of the temperature swing adsorption and isobaric drying mechanism (45) is connected with the output end of the pressure swing adsorption and purifying mechanism (46) through a pipeline, and the temperature swing adsorption and isobaric drying mechanism (45) is connected with the dust removal and filtering mechanism (4) through a pipeline, and the pressure swing adsorption and purifying mechanism (46) is connected with the water washing mechanism. The temperature swing adsorption and isobaric drying mechanism (45) is used for removing water, and the pressure swing adsorption and purifying mechanism (46) is used for removing nitrogen, carbon dioxide and residual water.

2. The energy-saving system for recycling oxygen from high-temperature oxygen-rich flue gas according to claim 1, characterized in that, The water washing mechanism comprises a flue gas inlet pipe (5) for connecting the high-temperature oxygen-enriched flue gas and a normal-temperature water pipe (6) for connecting the normal-temperature water, a first water washing tower (7) connected with the flue gas inlet pipe (5) and the normal-temperature water pipe (6), respectively, a drain pipe (8) and a second water washing tower (9) connected with the first water washing tower (7), and an outlet pipeline (10) connected with the second water washing tower (9) and the compressor set (1), respectively, wherein the cooling mechanism is connected with the second water washing tower (9) through a pipeline, and the pressure swing adsorption and purifying mechanism (46) is connected with the first water washing tower (7).

3. The energy-saving system for recycling oxygen from high-temperature oxygen-rich flue gas according to claim 2, characterized in that, The temperature swing adsorption constant pressure drying mechanism (45) includes a drying inlet pipe (11) connected with the gas-liquid separation tank (3), a first gas conveying pipe (12), a second gas conveying pipe (13) and a third gas conveying pipe (14) connected with the drying inlet pipe (11), a fourth gas conveying pipe (15) connected with the third gas conveying pipe (14), a first adsorption tower (16) and a second adsorption tower (17) connected with the first gas conveying pipe (12) and the second gas conveying pipe (13) respectively, a first output pipe (18) and a second output pipe (19) connected with the bottom of the first adsorption tower (16) and the second adsorption tower (17) respectively, a dried product gas pipe (20) connected with the first output pipe (18) and the second output pipe (19) respectively and used for outputting product gas, a pre-drying tower (21) connected with the third gas conveying pipe (14), a heater (22) connected with the pre-drying tower (21) in pipeline, a fifth gas conveying pipe (23) connected with the heater (22) at one end and connected with the first output pipe (18) and the second output pipe (19) through pipelines at the other end, a condenser (24) connected with the fourth gas conveying pipe (15), a gas-liquid separator (25) connected with the condenser (24) in pipeline, a sixth gas conveying pipe (26) connected between the third gas conveying pipe (14) and the fourth gas conveying pipe (15), a seventh gas conveying pipe (27) connected with the sixth gas conveying pipe (26) at one end and connected with the first output pipe (18) and the second output pipe (19) through pipelines at the other end, a plurality of first on-off valves (28) installed on the first gas conveying pipe (12), the second gas conveying pipe (13), the third gas conveying pipe (14), the fourth gas conveying pipe (15), the first output pipe (18), the second output pipe (19), the connecting pipeline of the fifth gas conveying pipe (23) and the first output pipe (18), the connecting pipeline of the fifth gas conveying pipe (23) and the second output pipe (19), the connecting pipeline of the seventh gas conveying pipe (27) and the first gas conveying pipe (12) and the connecting pipeline of the seventh gas conveying pipe (27) and the second gas conveying pipe (13) respectively, two second on-off valves (29) installed on the sixth gas conveying pipe (26), wherein the gas-liquid separator (25) is connected with the drying inlet pipe (11) in pipeline, the seventh gas conveying pipe (27) is connected on the sixth gas conveying pipe (26) and located between the two second on-off valves (29), and the dried product gas pipe (20) is connected with the output pipeline of the pressure swing adsorption purification mechanism (46).

4. The energy-saving system for recycling and purifying oxygen from high-temperature oxygen-rich flue gas according to claim 3, characterized in that, The pressure swing adsorption purification mechanism (46) comprises a pressure swing adsorption gas inlet pipe (30) connected with the gas-liquid separation tank (3), a plurality of pressure swing adsorption towers (31) connected with the bottom of the pressure swing adsorption gas inlet pipe (30) in a pipeline manner, a pressure swing adsorption gas outlet pipe (32) connected with the top of the pressure swing adsorption tower (31), a pressure swing adsorption product gas pipe (33) connected with each pressure swing adsorption gas outlet pipe (32) and connected with the dry product gas pipe (20), a pressure equalization mechanism connected with each pressure swing adsorption gas outlet pipe (32), a first regulating valve (34) connected with the pressure swing adsorption product gas pipe (33) and the pressure equalization mechanism at both ends, a pressure swing adsorption exhaust pipe (35) connected with the bottom of each pressure swing adsorption tower (31) in a pipeline manner, a pressure swing adsorption recovery pipe (36) connected with the bottom of each pressure swing adsorption tower (31) at one end and connected with the first water washing tower (7) at the other end, a third on-off valve (37) arranged on the pressure swing adsorption gas outlet pipe (32), the connecting pipeline between the pressure swing adsorption gas inlet pipe (30) and the bottom of the pressure swing adsorption tower (31), the connecting pipeline between the pressure swing adsorption exhaust pipe (35) and the bottom of the pressure swing adsorption tower (31), and the connecting pipeline between the pressure swing adsorption recovery pipe (36) and the bottom of the pressure swing adsorption tower (31), respectively, a pressure regulating valve (38) and a dust removal and filtration system (47) installed on the pressure swing adsorption product gas pipe (33), a recovery regulating valve (39) installed on the pressure swing adsorption recovery pipe (36), and a vacuum pump (40) installed on the pressure swing adsorption exhaust pipe (35), wherein the pressure swing adsorption product gas pipe (33) is connected with the dust removal and filtration mechanism (4).

5. The energy-saving system for recycling and purifying oxygen from high-temperature oxygen-rich flue gas according to claim 4, characterized in that, The pressure equalization mechanism comprises a plurality of pressure equalization pipes (41) connected with each pressure swing adsorption gas outlet pipe (32) in a pipeline manner, and a pressure equalization switch valve (42) installed on the connecting pipeline between the pressure equalization pipe (41) and each pressure swing adsorption gas outlet pipe (32), wherein the first regulating valve (34) is connected with one pressure equalization pipe (41).

6. The energy-saving system for recycling and purifying oxygen from high-temperature oxygen-rich flue gas according to claim 4, characterized in that, The number of the pressure swing adsorption towers (31) is at least 3.

7. The energy-saving system for recycling and purifying oxygen from high-temperature oxygen-rich flue gas according to claim 2, characterized in that, The cooling mechanism comprises a water chiller (43) connected with the compressor outlet heat exchanger (2) in a pipeline manner, and a low-temperature heat exchanger (44) connected with the water chiller (43) and the second water washing tower (9) in a pipeline manner, respectively.

8. The process of the energy-saving system for recycling and utilizing oxygen from high-temperature oxygen-rich flue gas to purify oxygen according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, water washing: The water washing mechanism is used to wash the high-temperature oxygen-enriched flue gas, to obtain low-temperature oxygen-enriched mixed gas, and the low-temperature oxygen-enriched mixed gas is input into the compressor unit (1); S2, compression and condensation: The low-temperature oxygen-enriched mixed gas is compressed and heated in the compressor unit (1), and then is input into the compressor outlet heat exchanger (2) to be cooled, and the cooled gas is input into the gas-liquid separation tank (3) to be separated, to obtain high-pressure low-temperature oxygen-enriched mixed gas; S3, temperature swing adsorption and isobaric drying and pressure swing adsorption purification: the step adopts a parallel process of temperature swing adsorption and isobaric drying and pressure swing adsorption purification, divides the high-pressure low-temperature oxygen-rich mixed gas into two, one is input into the temperature swing adsorption and isobaric drying mechanism (45) for drying to remove excess water to obtain low dew point oxygen-rich flue gas; the other is input into the pressure swing adsorption purification mechanism (46) to remove excess water, carbon dioxide and nitrogen to obtain low dew point high-purity oxygen; the low dew point oxygen-rich flue gas and the low dew point high-purity oxygen are mixed and input into the dust removal and filtration mechanism (4); S4, after the dust removal and filtration mechanism (4) removes dust from the mixed gas of the low dew point oxygen-rich flue gas and the low dew point high-purity oxygen, the product gas is output.

9. The energy-saving process for recycling oxygen from high-temperature oxygen-rich flue gas according to claim 8, characterized in that, The temperature swing adsorption and isobaric drying of step S3 includes the following steps: A1, hot blowing: a part of the high-pressure low-temperature oxygen-rich mixed gas is input from the drying gas inlet pipe (11) and sequentially treated by the pre-drying tower (21) and the heater (22) to heat the gas temperature to 150-170℃, and then input into the second adsorption tower (17) for hot blowing; after the hot blowing, the gas is sequentially cooled and separated from liquid water by the condenser (24) and the gas-liquid separator (25), and finally input into the drying gas inlet pipe (11) to be transported to the first adsorption tower (16) for adsorption; after the gas is adsorbed by the first adsorption tower (16), it is output from the drying product gas main pipe (20); A2, cold blowing: a part of the high-pressure low-temperature oxygen-rich mixed gas is input from the drying gas inlet pipe (11) and sequentially treated by the second adsorption tower (17) for cold blowing, then heated to 150-170℃ by the heater (22), and then input into the pre-drying tower (21) for heating and regeneration treatment; after the treatment, the gas is sequentially cooled and separated from liquid water by the condenser (24) and the gas-liquid separator (25), and finally input into the drying gas inlet pipe (11) to be transported to the first adsorption tower (16) for adsorption; after the gas is adsorbed by the first adsorption tower (16), it is output from the drying product gas main pipe (20); A3, exchange the work of the first adsorption tower (16) and the second adsorption tower (17) to make the first adsorption tower (16) sequentially perform hot blowing and cold blowing, and the second adsorption tower (17) perform adsorption; after the adsorption, the other is output from the drying product gas main pipe (20); A4, repeat steps A1-A3 to realize continuous drying of the high-pressure low-temperature oxygen-rich mixed gas.

10. The energy saving process for oxygen recovery from high temperature oxygen enriched flue gas according to claim 8, wherein, The pressure swing adsorption purification of step S3 includes the following steps: B1, adsorption: the high-pressure low-temperature oxygen-rich mixed gas is input from the bottom to the top of the pressure swing adsorption tower (31) from the pressure swing adsorption gas inlet pipe (30); after the adsorption by the pressure swing adsorption tower (31), the product gas is input from the top of the pressure swing adsorption tower (31) into the pressure swing adsorption product gas pipe (33) through the pressure swing adsorption output gas pipe (32), and finally input into the dust removal and filtration mechanism (4); B2, pressure equalization and pressure reduction: the high-pressure gas in the pressure swing adsorption tower (31) after adsorption is input into another pressure swing adsorption tower (31) through the pressure equalization mechanism to balance the gas pressure of the two towers; B3, reverse: reverse the adsorption direction, the pressure equalization after the pressure reduction of the pressure swing adsorption tower (31) gas through the pressure swing adsorption recovery pipe (36) into the first water washing tower (7) recovery, the pressure swing adsorption tower (31) in the gas pressure to normal pressure; B4, vacuum: reverse the adsorption direction, the reverse after the pressure swing adsorption tower (31) in the gas through the vacuum pump (40) and from the pressure swing adsorption exhaust pipe (35) exhaust; B5, pressure equalization: after the end of the vacuum, the pressure swing adsorption tower (31) through the pressure equalization mechanism receives the high pressure gas output by the pressure swing adsorption tower (31) in step B2, balance the gas pressure of the two towers; B6, final rise: in turn through the pressure swing adsorption product gas pipe (33), the first regulating valve (34), the pressure equalization mechanism, the pressure swing adsorption output gas pipe (32) to input the product gas into the pressure swing adsorption tower (31) after the pressure equalization, make the pressure swing adsorption tower (31) in the gas pressure uniform rise to the adsorption pressure; B7, repeat steps B1-B6, realize the high pressure low temperature oxygen enriched gas in the pressure swing adsorption purification mechanism (46) continuous removal of water, carbon dioxide and nitrogen.

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