Turbine pressure swing adsorption oxygen production device and use method thereof

Abstract

The invention relates to the technical field of industrial oxygen production, and particularly discloses a turbine pressure swing adsorption oxygen production device and a use method thereof.The device comprises an air pressurization module, an adsorption separation module, an energy recovery module, a product pressure stabilization and pressurization module and a control module; air separation oxygen generation is achieved through periodic adsorption and desorption of an adsorption tower in the adsorption separation module, and meanwhile the energy recovery module is used for converting pressure potential energy of impurity gas in the desorption process into mechanical energy so as to supply energy to the air pressurization module or generate electricity outwards. According to the use method, continuous oxygen production and energy recovery are realized through a circulation process of multi-tower alternate adsorption, desorption, pressure equalizing and flushing. The energy recovery module is communicated with the desorbed gas outlet of the adsorption separation module and is used for converting the pressure potential energy of the impurity gas discharged in the desorption process of the adsorption tower into mechanical energy, so that energy is recovered from the waste gas, and the energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial oxygen production, in particular to a turbo pressure swing adsorption oxygen production device and a use method thereof. BACKGROUND

[0002] Oxygen is widely used in metallurgy, chemical industry, environmental protection, energy, medical treatment and aquaculture as a basic industrial gas. At present, industrial oxygen production mainly adopts three technical paths: cryogenic rectification method, pressure swing adsorption method and membrane separation method. The cryogenic rectification method is mature in technology, and can produce high-purity oxygen, nitrogen, argon and other products, but has defects of complex equipment, large investment, wide occupation area and long start-up time (about 40 hours), and is not suitable for frequent start-stop or rapid gas supply scenes; The membrane separation method has simple equipment, but the product purity is low and the separation efficiency is limited, and the application range is narrow; The pressure swing adsorption method (PSA) realizes air separation at room temperature by using the selective adsorption characteristics of molecular sieve, has the advantages of simple device, compact structure, less investment, fast start-up (0.5-1 hour) and relatively low energy consumption, and although the upper limit of the product oxygen purity is 90%-93%, it has become the mainstream technology for low-cost oxygen production in most industrial fields.

[0003] In the pressure swing adsorption method, the vacuum pressure swing adsorption (VPSA) oxygen production technology is a commonly used type, and its principle is: by using the strong adsorption of zeolite molecular sieve to nitrogen and carbon dioxide and the weak adsorption to oxygen, impurities are adsorbed and desorbed through periodic pressure change, so as to enrich oxygen. The traditional VPSA oxygen production system mainly consists of a blower, multiple adsorption towers, a vacuum pump, program-controlled switching valves and an oxygen buffer tank. When working, the blower is driven by a motor to pressurize the raw air, and the vacuum pump is driven to provide a negative pressure environment for the adsorption tower. Double motor driving leads to high energy consumption of the system, which restricts the energy saving potential of the VPSA oxygen production technology. SUMMARY

[0004] The present application aims to provide a turbo pressure swing adsorption oxygen production device and a use method thereof, which can solve the above technical problems.

[0005] The present application provides a turbo pressure swing adsorption oxygen production device, which comprises an air pressurization module, an adsorption separation module, an energy recovery module and a product pressure stabilization and pressurization module, and further comprises a control module. The air pressurization module is used for pressurizing raw air to a preset adsorption pressure, and comprises at least one air compression device. The adsorption separation module is in communication with the air outlet of the air pressurization module, and is used for adsorbing and separating the pressurized raw air to obtain oxygen, and comprises at least two adsorption towers filled with molecular sieve inside, and multiple groups of program-controlled switching valves for controlling gas path switching. The energy recovery module is in communication with the desorption gas outlet of the adsorption separation module, and is used for converting the pressure potential energy of the impurity gas discharged in the desorption process of the adsorption tower into mechanical energy, and comprises at least one rotary machine capable of converting fluid energy into mechanical energy; The product pressure stabilizing and pressurizing module is in communication with the product gas outlet of the adsorption separation module, and is used for stabilizing the oxygen pressure and pressurizing the oxygen. The control module is electrically connected with the air pressurizing module, the adsorption separation module, the energy recovery module and the product pressure stabilizing and pressurizing module, and is used for controlling the modules to operate according to the preset program.

[0006] Preferably, the air compression device is a centrifugal blower or a Roots blower.

[0007] Preferably, the rotary machine is one of a radial turbine, a radial flow turbine, an axial flow turbine, an expander and a turbine machine.

[0008] Preferably, the energy recovery module further comprises an energy utilization assembly.

[0009] Preferably, the energy utilization assembly is a generator, an input end of the generator is connected with an output end of the rotary machine through gear transmission or belt transmission, mechanical energy generated by the rotary machine is converted into electric energy, and the generator is further electrically connected with an energy storage unit.

[0010] Preferably, the energy utilization assembly is a transmission structure coaxially connected with the air pressurizing module, and the rotary machine transmits mechanical energy to the air pressurizing module through the transmission structure to assist the air pressurizing module to operate.

[0011] Preferably, the product pressure stabilizing and pressurizing module comprises an oxygen buffer tank, an outlet of the oxygen buffer tank is connected with an oxygen compressor, and the oxygen compressor is used for pressurizing the oxygen to a target pressure.

[0012] Preferably, the program-controlled switch valve is an electromagnetic valve or a pneumatic valve, and the number of the program-controlled switch valves is matched with the number of the adsorption towers and the number of the gas path channels, and the program-controlled switch valves are used for controlling the inlet of the raw material air, the outlet of the product gas and the discharge of the desorption gas.

[0013] Preferably, the control module is a PLC programmable controller, the PLC programmable controller is pre-set with control programs of adsorption, desorption, pressure equalization, flushing and switching, and the PLC programmable controller is electrically connected with the motor of the air pressurizing module, the program-controlled switch valve, the pressure sensor of the energy recovery module and the product pressure stabilizing and pressurizing module, and is used for monitoring the operating parameters of the modules in real time and adjusting the operating states.

[0014] The application further provides a use method of the turbine variable pressure adsorption oxygen generating device. S1. Adsorption oxygen production: the control module opens the air pressurization module and the gas path valve of the first adsorption tower in the adsorption separation module, raw air enters the first adsorption tower after being pressurized by the air pressurization module, the molecular sieve selectively adsorbs nitrogen, carbon dioxide and water vapor in the air, and the separated oxygen enters the product pressure stabilizing and pressurizing module through the product gas outlet; S2. Desorption regeneration: while the first adsorption tower is adsorbing, the control module opens the gas path valve of the second adsorption tower in the adsorption separation module and the energy recovery module, the pressure in the second adsorption tower is reduced to normal pressure, the impurity gas adsorbed by the molecular sieve is desorbed and discharged to the energy recovery module, the impurity gas drives the energy recovery module to operate, and energy recovery is realized; S3. Pressure equalization flushing: when the adsorption of the first adsorption tower approaches saturation and the desorption of the second adsorption tower is completed, the control module opens the communication valve of the first adsorption tower and the second adsorption tower, part of the high-pressure gas in the first adsorption tower enters the second adsorption tower to realize pressure equalization; at the same time, the control module opens the gas path valve of the product pressure stabilizing and pressurizing module and the second adsorption tower, and controls a small amount of product oxygen from the pressure stabilizing and pressurizing module to reversely purge the second adsorption tower to remove residual impurity gas; S4. Switching cycle: the control module switches the opening and closing states of each program-controlled switching valve, so that the second adsorption tower enters the adsorption oxygen production state, the first adsorption tower enters the desorption regeneration state, and steps S1-S3 are repeated to realize continuous oxygen production.

[0015] Beneficial effects: The energy recovery module of the present application is in communication with the desorption gas outlet of the adsorption separation module, which is used to convert the pressure potential energy of the impurity gas discharged in the desorption process of the adsorption tower into mechanical energy, realizes energy recovery from waste gas, and reduces energy consumption. BRIEF DESCRIPTION OF DRAWINGS In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating any inventive labor.

[0016] Figure 1 It is a schematic diagram of the overall structure of embodiment 1 of the present application; Figure 2 It is a schematic diagram of the overall structure of embodiment 2 of the present application.

[0017] Legend: 1-generator, 2-blower, 3-first adsorption tower, 4-oxygen buffer tank, 5-oxygen compressor, 6-second adsorption tower, 7-electric motor, 8-turbine. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0019] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0020] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited. In addition, the terms "mounting", "connecting", "connection" should be broadly understood, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] The present application is applied to TPSA technology. The TPSA oxygen production technology is similar to the VPSA oxygen production technology. The core of both is to use the selective adsorption of molecular sieve (such as zeolite) and the periodic change of pressure in the system to adsorb and reduce impurity gases (carbon dioxide, water vapor, etc.) other than oxygen to retain oxygen in air to realize air separation oxygen production. The difference between TPSA and VPSA is that TPSA does not need negative pressure to desorb oxygen, and cancels the vacuum pump at the outlet of the system to create a negative pressure environment. The present application uses a turbine instead. The turbine can be coaxial with the inlet blower, or connected to a generator. When the reduced impurity gas passes through the turbine, the gas flow drives the turbine to rotate, so that the pressure potential energy of the gas is converted into the mechanical energy of the impeller rotation, and is transmitted to the inlet blower or the generator through the shaft to generate electricity, realizing part of the energy recovery while producing oxygen.

[0022] Example 1 like Figure 1 As shown, the device of the present invention includes a blower 2: responsible for pressurizing the raw material air to a higher adsorption pressure; Two adsorption towers: The first adsorption tower 3 and the second adsorption tower 6 are filled with molecular sieves for alternating adsorption and regeneration (reduction). A series of programmable switching valves: Figure 1 The eight valves shown are used to automatically control the airflow direction and circulation steps; Centripetal turbine / radial flow turbine / axial flow turbine / expander / turbine / turbine machinery / any rotating machinery that can convert the energy of a fluid into mechanical energy (collectively referred to as turbine 8): used to convert the pressure potential energy of reducing gas (impurity gas) into mechanical energy to supply a coaxial blower; Oxygen buffer tank 4: Used to stabilize the pressure and flow rate of product gas; Oxygen compressor 5: Used to pressurize the produced oxygen.

[0023] The mechanical energy generated by the rotation of the aforementioned rotating machinery through fluid can be directly transmitted to the blower through the same shaft, and the auxiliary motor 7 drives the blower 2. This eliminates the conversion step of "mechanical energy to electrical energy and back to mechanical energy", reduces energy conversion losses, and significantly improves the overall energy utilization efficiency of the system.

[0024] Traditional blowers are typically driven solely by electric motor 7. However, with coaxial connection, blower 2 can simultaneously receive mechanical work from turbine 8 and power from electric motor 7. The blower is primarily driven by the electric motor, with the turbine serving as auxiliary power, thus reducing power consumption. Furthermore, to avoid "mutual interference" between the turbine and the blower, some systems are equipped with a clutch or hydraulic coupling: when the turbine speed is too low or malfunctions, the mechanical connection with the blower can be severed, ensuring that the blower can still operate stably independently by the electric motor.

[0025] Example 2 The basic structure is the same as in Example 1, except that the energy utilization component is a generator 1. The input end of the generator 1 is connected to the output end of the rotating machinery (turbine 8) through gear transmission or belt transmission, so as to convert the mechanical energy generated by the rotating machinery into electrical energy.

[0026] Workflow description: 1) Oxygen production by adsorption: The raw air is pressurized by a centrifugal blower and enters the first adsorption tower. Under an environment higher than atmospheric pressure, the molecular sieve's adsorption capacity for nitrogen and other impurity gases is greatly enhanced, thus "capturing" and fixing a large amount of impurity gases in the air within the sieve pores. Oxygen, which is not easily adsorbed, passes smoothly through the molecular sieve and flows out from the top of the tower as the product gas.

[0027] 2) Desorption Regeneration: While the first adsorption column is undergoing high pressure adsorption, the second adsorption column, which has been saturated, is connected to the atmosphere, and the pressure in the column is rapidly reduced from high pressure to normal pressure. With the significant reduction in pressure, the adsorption capacity of the molecular sieve for impurity gas is sharply weakened, and the previously adsorbed nitrogen is naturally desorbed and released from the column. This process is the normal pressure desorption, which restores the activity of the molecular sieve in the second adsorption column and completes the regeneration.

[0028] During the desorption process, the desorbed impurity gas is discharged from the adsorption column to the outlet at a certain flow rate under the pressure gradient. The impurity gas carries a certain amount of energy into the centrifugal turbine at the outlet, which drives the turbine to rotate and do work. The enthalpy (energy) of the gas is converted into mechanical energy of the turbine rotation, and is transmitted to the coaxial blower or external generator through the shaft to realize energy recovery.

[0029] 3) Equalization and Purging: To improve efficiency and completeness of regeneration, the system includes an equalization and purging step. Before switching, the first adsorption column (high pressure) is briefly connected to the second adsorption column (normal pressure) to recover part of the gas. At the same time, a small part of the product oxygen can also be used to backflush the second adsorption column to help remove residual nitrogen.

[0030] 4) Switching and Cycling: When the first adsorption column is about to be saturated and the second adsorption column is regenerated, the control system switches the valve to let the compressed air enter the second adsorption column for high pressure adsorption, while the first adsorption column starts normal pressure desorption regeneration. This cycle is repeated to realize continuous production of oxygen.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A turbo-PSA oxygen generating device, characterized by, It includes an air pressurization module, an adsorption separation module, an energy recovery module, and a product pressure stabilization and boosting module, as well as a control module; The air pressurization module is used to pressurize the raw material air to a preset adsorption pressure, and it includes at least one air compression device; The adsorption separation module is connected to the air outlet of the air pressurization module and is used to adsorb and separate the pressurized raw material air to obtain oxygen. It includes at least two adsorption towers filled with molecular sieves and multiple sets of programmable switching valves for controlling the gas path switching. The energy recovery module is connected to the desorption gas outlet of the adsorption separation module and is used to convert the pressure potential energy of the impurity gas discharged during the desorption process of the adsorption tower into mechanical energy. It includes at least one rotating mechanism that can convert fluid energy into mechanical energy. The product pressure stabilization and boosting module is connected to the product gas outlet of the adsorption separation module, and is used to stabilize the oxygen pressure and boost the oxygen. The control module is electrically connected to the air pressurization module, adsorption separation module, energy recovery module, and product pressure stabilization and boosting module, and is used to control each module to operate according to a preset program.

2. The pressure swing adsorption oxygen generation device of claim 1, wherein, The air compression device is a centrifugal blower or a Roots blower.

3. The pressure swing adsorption turbo-oxygen generating device according to claim 1, wherein, The rotating machinery is one of the following: centripetal turbine, radial turbine, axial turbine, expander, and turbine machinery.

4. The pressure swing adsorption turbo-oxygen generating device according to claim 1, wherein, The energy recovery module also includes an energy utilization component.

5. The pressure swing adsorption oxygen generation device of claim 4, wherein, The energy utilization component is a generator. The input end of the generator is connected to the output end of the rotating machinery through gear transmission or belt transmission, converting the mechanical energy generated by the rotating machinery into electrical energy. The generator is also electrically connected to an energy storage unit.

6. The pressure swing adsorption turbo-oxygen generating device according to claim 4, wherein, The energy utilization component is a transmission structure coaxially connected to the air pressurization module. The rotating machinery transmits mechanical energy to the air pressurization module through the transmission structure to assist the air pressurization module in operation.

7. The PSA oxygen generation device of claim 1, wherein, The product pressure stabilization and boosting module includes an oxygen buffer tank, the outlet of which is connected to an oxygen compressor, which is used to boost the oxygen to the target pressure.

8. The PSA oxygen generation device of claim 1, wherein, The programmable switching valve is a solenoid valve or a pneumatic valve, and the number of programmable switching valves is adapted to the number of adsorption towers and the number of gas passages, and is used to control the entry of raw material air, the output of product gas and the discharge of desorbed gas.

9. The PSA oxygen generation device of claim 1, wherein, The control module is a PLC programmable controller. The PLC programmable controller has preset control programs for adsorption, desorption, pressure equalization, rinsing and switching. The PLC programmable controller is electrically connected to the motor of the air pressurization module, the programmable switching valve, the energy recovery module and the pressure sensor of the product pressure stabilization and boosting module, and is used to monitor the operating parameters of each module in real time and adjust the operating status.

10. A method of using a turbo-PSA oxygen generation device, based on the turbo-PSA oxygen generation device of any one of claims 1-9, wherein, Includes the following steps: S1. Oxygen production by adsorption: The control module opens the gas valve of the first adsorption tower in the air pressurization module and the adsorption separation module. The raw air enters the first adsorption tower after being pressurized by the air pressurization module. The molecular sieve selectively adsorbs nitrogen, carbon dioxide and water vapor in the air. The separated oxygen enters the product pressure stabilization and boosting module through the product gas outlet. S2. Desorption regeneration: while the first adsorption tower is adsorbing, the control module opens the gas path valve between the second adsorption tower, which has been adsorbed and saturated, in the adsorption separation module and the energy recovery module, the pressure in the second adsorption tower is reduced to normal pressure, the impurity gas adsorbed by the molecular sieve is desorbed and discharged to the energy recovery module, the impurity gas drives the energy recovery module to operate, and energy recovery is achieved; S3. Pressure equalization flushing: when the adsorption of the first adsorption tower is close to saturation and the desorption of the second adsorption tower is completed, the control module opens the communication valve between the first adsorption tower and the second adsorption tower, part of the high-pressure gas in the first adsorption tower enters the second adsorption tower to achieve pressure equalization; at the same time, the control module opens the gas path valve between the product pressure stabilizing and pressurizing module and the second adsorption tower, and controls a small amount of product oxygen from the pressure stabilizing and pressurizing module to reversely purge the second adsorption tower, so as to remove the residual impurity gas; S4. Switching cycle: the control module switches the on-off state of each program-controlled switching valve, so that the second adsorption tower enters the adsorption oxygen production state, the first adsorption tower enters the desorption regeneration state, and steps S1-S3 are repeated to realize continuous oxygen production.

Images