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CN-122006411-A - Gas suspension oil-free VPSA oxygen production system capable of actively recovering residual gas

CN122006411ACN 122006411 ACN122006411 ACN 122006411ACN-122006411-A

Abstract

The invention relates to the technical field of pressure swing adsorption gas separation, and discloses a gas suspension oil-free VPSA oxygen production system for actively recovering residual gas. The gas circuit switching module is integrated with a tower top pressure equalizing regulating valve with opening continuous regulating capability, a tower bottom pressure equalizing control valve and a tower bottom air supplementing component which independently and pneumatically passes through. The central control module performs cooperative control based on real-time differential pressure data, and in the pressure equalizing process, the opening of the pressure equalizing regulating valve at the top of the tower is controlled to be dynamically regulated in an opposite phase to the real-time differential pressure, the flow rate is limited to prevent pulverization of a bed layer, the pressure equalizing control valve at the bottom of the tower is synchronously opened to recover bottom dead space gas potential energy, and in the initial stage of pressure rising and falling, the natural differential pressure between the adsorption tower and the atmosphere is utilized to control the air supplementing assembly to realize unpowered auxiliary air intake and exhaust. The invention can effectively reduce the energy consumption of the system operation, prevent the pulverization of the molecular sieve and improve the oxygen production efficiency.

Inventors

  • XIE BANGQING
  • XIAO FENG
  • XIONG JIANBING
  • ZHANG WENHUA

Assignees

  • 成都联帮医疗科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The utility model provides a gas suspension oil-free VPSA oxygen system that residual gas initiatively retrieves which characterized in that includes: The oxygen generation host module is provided with a first adsorption tower (11) and a second adsorption tower (12) which are arranged in parallel, molecular sieves are filled in the first adsorption tower (11) and the second adsorption tower (12), and the gas power input end of the oxygen generation host module is connected with external gas power equipment to introduce compressed air and provide vacuum suction power; the gas circuit switching module is arranged in a gas pipeline network of the oxygen-making host module and comprises a tower top pressure equalizing component (21), a tower bottom pressure equalizing component (22) and a tower bottom air supplementing component (23) which are used for controlling the gas flow direction, pressure balance and interaction with external atmosphere in the system; the buffer output module is connected with the output end of the gas circuit switching module, and is used for collecting the oxygen-enriched air produced by the first adsorption tower (11) or the second adsorption tower (12) through an oxygen buffer tank (3001) and stabilizing the output pressure; The central control module is connected with the oxygen generation host module, the gas circuit switching module and the sensing device and the actuating mechanism in the buffer output module, and is used for cooperatively controlling the valve opening change rate of the tower top pressure equalizing component (21), the on-off time sequence of the tower bottom pressure equalizing component (22) and the communication state of the tower bottom air supplementing component (23) and the atmosphere based on the acquired real-time pressure parameters and current parameters so as to realize smooth transition of the internal pressure of the adsorption tower and recovery of residual potential energy.
  2. 2. The gas suspension oil-free VPSA oxygen production system for actively recovering residual gas according to claim 1, wherein the tower top pressure equalizing component (21) comprises a tower top pressure equalizing pipeline (2101), a tower top pressure equalizing regulating valve (2102) and an oxygen outlet pipeline (2103), two ends of the tower top pressure equalizing pipeline (2101) are respectively and hermetically connected to top outlets of the first adsorption tower (11) and the second adsorption tower (12) to form a bidirectional gas channel, the tower top pressure equalizing regulating valve (2102) is serially arranged at the middle section of the tower top pressure equalizing pipeline (2101), the tower top pressure equalizing regulating valve (2102) is configured to be provided with an electric regulating valve capable of receiving analog quantity control signals to continuously regulate the opening degree of a valve core, and the buffer output module is connected with the top of the first adsorption tower (11) and the top of the second adsorption tower (12) in parallel connection with the tower top pressure equalizing pipeline (2101) through the oxygen outlet pipeline (2103).
  3. 3. The gas suspension oil-free VPSA oxygen generation system for actively recovering residual gas according to claim 1, wherein the tower bottom pressure equalizing component (22) comprises a tower bottom gas inlet and outlet pipeline (2201), a tower bottom pressure equalizing control valve (2202) and a tower bottom pressure equalizing pipeline (2203), two ends of the tower bottom gas inlet and outlet pipeline (2201) are respectively and fixedly connected with a bottom gas inlet end of the first adsorption tower (11) and a bottom gas inlet end of the second adsorption tower (12) to form a communication structure, two ends of the tower bottom pressure equalizing pipeline (2203) are respectively communicated with a side wall of the tower bottom gas inlet and outlet pipeline (2201), and the tower bottom pressure equalizing control valve (2202) is installed on a pipeline path of the tower bottom pressure equalizing pipeline (2203) to control direct communication and interception between two adsorption tower bottoms; The tower bottom air supplementing assembly (23) comprises an air supplementing branch pipeline (2301), an air supplementing valve (2302) and a silencing and filtering assembly (2303), one ends of the two air supplementing branch pipelines (2301) are respectively connected to the bottoms of the first adsorption tower (11) and the second adsorption tower (12), the other end of the air supplementing branch pipeline (2301) is fixedly connected with the air supplementing valve (2302), and one end of the air supplementing valve (2302) is fixedly connected with the silencing and filtering assembly (2303).
  4. 4. The gas suspension oilless VPSA oxygen production system for actively recovering residual gas according to claim 3, wherein the silencing and filtering component (2303) in the tower bottom air supplementing component (23) comprises a resistive silencer structure and an air filter screen covered on an air inlet end surface, the effective flow cross section area of the silencing and filtering component (2303) is larger than the pipeline cross section area of the air supplementing branch pipeline (2301), when the air supplementing valve (2302) is opened and the pressure in the adsorption tower is higher than the atmospheric pressure, the gas in the tower is discharged to the atmosphere, and when the air supplementing valve (2302) is opened and the pressure in the adsorption tower is lower than the atmospheric pressure, the air is filtered and then sucked into the adsorption tower.
  5. 5. The gas suspension oilless VPSA oxygen generation system of claim 4, wherein the sensing device connected to the central control module comprises: the first pressure transmitter is arranged at the top of the first adsorption tower (11) and is used for acquiring an instantaneous absolute pressure value in the first adsorption tower (11); the second pressure transmitter is arranged at the top of the second adsorption tower (12) and is used for acquiring an instantaneous absolute pressure value in the second adsorption tower (12); The environment pressure monitoring unit is used for collecting real-time atmospheric pressure of the environment where the equipment is located; and the current detection element is connected in series in the power supply loop of the external aerodynamic device and is used for detecting a load current signal.
  6. 6. The gas suspension oil free VPSA oxygen generation system of claim 5, wherein the central control module is configured to execute active equalization control logic of overhead residual gas: when the adsorption period is over, the central control module calculates a real-time pressure difference between the first adsorption tower (11) and the second adsorption tower (12); When the real-time pressure difference is larger than a preset starting pressure difference threshold value, the central control module sends an opening instruction to a tower top pressure equalizing regulating valve (2102); In the pressure equalizing process, the opening of the tower top pressure equalizing regulating valve (2102) is dynamically regulated according to the real-time pressure difference data calculated in real time, so that the opening of the tower top pressure equalizing regulating valve (2102) and the real-time pressure difference data are in an inverse correlation change relation, and the gas flow rate in the initial large pressure difference stage is limited in a preset range to prevent pulverization of a molecular sieve bed.
  7. 7. The gas suspension oil free VPSA oxygen generation system of active residual gas recovery of claim 6, wherein the central control module is configured to perform a function model based valve opening adjustment, the target opening of the overhead pressure equalizing adjustment valve (2102) being set to a sum of a preset minimum starting opening and a dynamic opening adjustment amount; The dynamic opening adjustment is configured to be in direct proportion to the current attenuation proportion of the real-time pressure difference data relative to the starting pressure difference threshold value, and the tower top pressure equalizing adjustment valve (2102) is controlled to be closed until the real-time pressure difference data falls to a cut-off threshold value.
  8. 8. The gas suspension oil free VPSA oxygen system of claim 6, wherein the central control module is configured to perform bypass balance control logic for bottom potential energy exchange: Synchronously controlling the tower bottom pressure equalizing control valve (2202) to be in a full-open state during the execution of the active pressure equalizing control logic, so that the gas at the bottom of the high-pressure side adsorption tower bypasses the external aerodynamic device and directly flows to the bottom of the low-pressure side adsorption tower; And monitoring the change rate of the real-time pressure difference in real time, and closing the tower bottom pressure equalizing control valve (2202) when the change rate is smaller than a preset slowing threshold value or when the pressure of the high-pressure side adsorption tower is reduced to a preset middle pressure value.
  9. 9. The gas suspension oil free VPSA oxygen generation system of claim 6, wherein the central control module is configured to execute natural gas intake and exhaust control logic based on differential atmospheric pressure: Judging whether the internal pressure of the adsorption tower at the initial stage of depressurization is higher than the sum of the real-time atmospheric pressure and the positive pressure difference set by the exhaust gas, if so, controlling a main process valve group connected with the external gas power equipment to be closed or kept closed, opening a corresponding air supplementing valve (2302), exhausting the gas in the tower to the atmosphere by utilizing the pressure difference until the pressure is close to the real-time atmospheric pressure, closing the air supplementing valve (2302) and switching to a vacuum pumping process; And if so, controlling a main process valve group connected with the external gas power equipment to be closed or kept closed, opening a corresponding air supplementing valve (2302), sucking external air into the tower by utilizing the pressure difference, closing the air supplementing valve (2302) until the pressure is close to the real-time atmospheric pressure, and switching to an active pressurizing process.
  10. 10. The gas suspension oil-free VPSA oxygen generation system for active recovery of residual gas of claim 9, wherein a logic interlock program is provided in the central control module, the logic interlock program comprising: During the opening period of the tower bottom equalizing control valve (2202), the corresponding air compensating valves (2302) of the first adsorption tower (11) and the second adsorption tower (12) are forcedly locked to be in a closed state; during the opening of any one of the air compensating valves (2302), the main process valve group between the corresponding adsorption tower and the external aerodynamic device is forcibly locked to be in a closed state, or the external aerodynamic device is controlled to be in an unloading state.

Description

Gas suspension oil-free VPSA oxygen production system capable of actively recovering residual gas Technical Field The invention relates to the technical field of pressure swing adsorption gas separation, in particular to a gas suspension oil-free VPSA oxygen production system for actively recovering residual gas. Background The Vacuum Pressure Swing Adsorption (VPSA) oxygen production technology utilizes the selective adsorption characteristic of molecular sieves, separates oxygen from air through periodical pressurized adsorption and vacuum desorption circulation, and is widely applied to the industrial and medical oxygen supply fields by virtue of the advantages of quick start, high automation degree and the like. In actual operation, in order to improve oxygen recovery, the system typically performs a pressure equalization operation in the adsorption column pressure switching gap. However, the conventional pressure equalizing control logic mostly adopts a cut-off valve with a switching function, a large pressure gradient exists between a high-pressure tower and a low-pressure tower at the pressure equalizing starting moment, and the instantaneous full opening of the valve can cause the rapid increase of the airflow velocity in the pipeline. The uncontrolled high-speed airflow impact directly acts on the molecular sieve bed, so that the relative displacement and friction of adsorbent particles are very easy to occur, even the bed boiling phenomenon is caused, the molecular sieve pulverization generated by long-term operation can block airflow channels, and the service life and separation performance of the system are seriously affected. In addition, the conventional VPSA technology has limitation on energy consumption management, mainly relies on power equipment such as Roots blowers or vacuum pumps to carry out whole-course forced transportation, and cannot effectively utilize the natural pressure difference between the internal pressure of the adsorption tower and the external atmospheric pressure. In the transition stage of the adsorption tower from positive pressure to vacuum or from vacuum to positive pressure, the existing system often directly starts the intervention of the power equipment, and omits the passive air exhaust pressure relief or natural air suction pressure boost by utilizing the pressure difference communicated with the atmosphere, so that the power equipment has long running time under the low-efficiency working condition. Meanwhile, the pressure potential energy of the gas remained in the dead space at the bottom of the adsorption tower is generally directly emptied or idled, and an effective recovery mechanism is lacked, so that the improvement of the overall operation energy efficiency of the device is limited. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a gas suspension oil-free VPSA oxygen production system for actively recovering residual gas, which solves the problems that molecular sieves are easy to pulverize due to air flow impact in the pressure equalizing switching process of the existing VPSA oxygen production system, and the energy consumption of the system is higher due to insufficient utilization of natural pressure difference and residual gas potential energy at the bottom of a tower. In order to achieve the purpose, the invention is realized by the following technical scheme that the gas suspension oil-free VPSA oxygen production system for actively recovering residual gas comprises: The oxygen generation host module is provided with a first adsorption tower and a second adsorption tower which are arranged in parallel, molecular sieves are filled in the first adsorption tower and the second adsorption tower, and the gas power input end of the oxygen generation host module is connected with external gas power equipment to introduce compressed air and provide vacuum suction power; the gas circuit switching module is arranged in a gas pipeline network of the oxygen-making host module and comprises a tower top pressure equalizing component, a tower bottom pressure equalizing component and a tower bottom air supplementing component, and is used for controlling the gas flow direction, pressure balance and interaction with external atmosphere in the system; The buffer output module is connected with the output end of the gas circuit switching module, and the oxygen-enriched air produced by the first adsorption tower or the second adsorption tower is collected through the oxygen buffer tank and the output pressure is stabilized; The central control module is connected with the oxygen generation host module, the gas circuit switching module and the sensing device and the actuating mechanism in the buffer output module, and is used for cooperatively controlling the valve opening change rate of the tower top pressure equalizing component (21), the on-off time sequence of the tower bottom pressure equalizing component (22) and the com