Energy-saving low-pressure PSA (Pressure Swing Adsorption) center oxygen enrichment system and oxygen supply method thereof

Abstract

The invention discloses an energy-saving low-pressure PSA (Pressure Swing Adsorption) center oxygen enrichment system and an oxygen supply method thereof, and relates to the technical field of oxygen supply devices.The energy-saving low-pressure PSA center oxygen enrichment system comprises an oxygen generator set for preparing an oxygen source, the oxygen generator set is composed of one or more oxygen generators, and each oxygen generator is composed of one or more independent oxygen generation units; the buffer tank is connected with the oxygen making unit, the air outlet end of the buffer tank is connected with a main oxygen supply pipeline, and the main oxygen supply pipeline is connected with a first one-way valve, a flow meter and a pressure sensor in series; according to the invention, the control system detects the pressure of the buffer tank, the pressure of the oxygen storage tank, the oxygen flow and pressure on the main pipeline and other information, calculates the time of each oxygen generation unit and the booster pump, automatically adjusts the number of started oxygen generation units and whether to pressurize and store oxygen, and ensures that the working time of each oxygen generator (or oxygen generation unit) is close to each other. The system is long in service life, low in energy consumption, good in oxygen enrichment effect and long in oxygen supply distance.

Description

Technical Field

[0001] This invention specifically relates to the field of oxygen supply device technology, and more specifically to an energy-saving low-pressure PSA central oxygen enrichment system and its oxygen supply method. Background Technology

[0002] After about 15 years of large-scale development, diffuse oxygen enrichment in high-altitude areas has gradually evolved into central oxygen enrichment systems with higher adsorption and output pressures, and diffuse oxygen generators with lower adsorption and output pressures. A central oxygen enrichment system consists of one or more oxygen generators forming a central oxygen source, with oxygen delivered from the machine room to various oxygen-enriched spaces via pipelines.

[0003] Central oxygen sources typically use screw compressors to supply compressed air, with an outlet air pressure of approximately 7.5 bar. Therefore, the energy consumption per unit of oxygen production is relatively high, generally around [amount missing] per cubic meter of oxygen.

[0004] Between 1.5 kWh and 2.0 kWh. Central oxygen enrichment systems, due to their higher pressure, can directly deliver oxygen into the oxygen-enriched space. Diffuse oxygen generators generally use reciprocating compressors to provide compressed air, with a compressor discharge pressure of approximately 1.5 bar. Using an AC reciprocating compressor, the energy consumption is approximately 1.2 kWh per cubic meter of oxygen, while using a DC reciprocating compressor, the energy consumption is approximately 0.8 kWh per cubic meter of oxygen.

[0005] However, because the outlet pressure of a diffusion-type oxygen concentrator is generally only 0.3 to 0.7 bar, a principle of proximity installation is adopted, meaning that one or more diffusion-type oxygen concentrators are distributed to supply oxygen to one or more spaces, resulting in decentralized equipment and on-demand supply. When a diffusion-type oxygen concentrator is enriching oxygen, it turns on whenever oxygen is needed downstream. When the designed output of the oxygen concentrator exceeds the oxygen consumption, the oxygen outlet pressure increases, and some oxygen is trapped in the adsorption tower and consumed through the backflush pipeline, greatly increasing energy consumption. Furthermore, because the compressor outlet pressure is forced to increase, the compressor's lifespan is reduced. Summary of the Invention

[0006] The purpose of this invention is to provide an energy-saving low-pressure PSA central oxygen enrichment system and its oxygen supply method. The control system detects information such as buffer tank pressure, oxygen storage tank pressure, and oxygen flow and pressure on the main pipeline, and calculates the operating time of each oxygen generating unit and booster pump. It automatically adjusts the number of oxygen generating units activated, whether the micro-boost mechanism intervenes, and whether pressurization and oxygen storage are performed, ensuring that the operating time of each oxygen generator (or oxygen generating unit) is approximately the same. This ensures a long system lifespan, reduced energy consumption, good oxygen enrichment effect, and long oxygen delivery distance, thereby solving the technical problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An energy-saving low-pressure PSA central oxygen enrichment system includes an oxygen generator unit for preparing oxygen sources. The oxygen generator unit consists of one or more oxygen generators, and each oxygen generator consists of one or more independent oxygen generating units.

[0009] It also includes a buffer tank connected to the oxygen generator unit. The outlet of the buffer tank is connected to the main oxygen supply pipeline, and a first check valve, a flow meter and a pressure sensor are connected in series on the main oxygen supply pipeline.

[0010] The micro-increase mechanism, used for bypassing the main oxygen supply pipeline and increasing the oxygen source, is connected in parallel with the first one-way valve;

[0011] The main oxygen supply pipeline is connected to a booster pump unit via a three-way valve and a pipeline. The booster pump unit is connected to the air inlet of the oxygen storage tank. A fourth check valve is connected in series between the booster pump unit and the oxygen storage tank.

[0012] If an oxygen supply pipeline is connected between the main oxygen supply pipeline and the outlet of the oxygen storage tank, then an oxygen supply valve is connected in series on the oxygen supply pipeline.

[0013] As a further technical solution of the present invention, a first pressure sensor is installed on the buffer tank; a second pressure sensor is connected in series on the oxygen storage tank.

[0014] As a further technical solution of the present invention, the micro-boosting mechanism includes a micro-boosting pump, and a second one-way valve and a silencer are connected in series at the outlet end of the micro-boosting pump.

[0015] As a further technical solution of the present invention, the pump set includes one or more booster pumps connected in parallel, and a third check valve is connected in series at the outlet end of each booster pump.

[0016] As a further technical solution of the present invention, a pressure relief valve is added to the outside of the pump unit. One end of the pressure relief valve is connected to the main oxygen supply pipeline through a pipeline, and the other end is connected to the front end of the fourth one-way valve.

[0017] As a further technical solution of the present invention, the pressure range of the buffer tank is 0 to 100 kPa; the detection range of the first pressure sensor covers 0 to 100 kPa.

[0018] As a further technical solution of the present invention, the oxygen supply pressure of the micro-increase mechanism is within 0.1 MPa.

[0019] An oxygen supply method for an energy-saving low-pressure PSA central oxygen-enrichment system includes the following steps:

[0020] A. Oxygen generation and supply: The oxygen generator unit provides compressed air from a DC compressor or an AC compressor; the oxygen generated by the oxygen generator unit is transported to a buffer tank for buffering; and then oxygen is supplied to the equipment through the main oxygen supply pipeline;

[0021] B. Micro-pressurized oxygen supply: The need for micro-pressurization mechanism intervention is determined based on the length of the main oxygen supply pipeline and the pressure feedback from the pressure sensor. When intervention is required, the micro-pressurization pump is turned on to pressurize the oxygen through bypass, and after being silenced by the silencer chamber, it is delivered to the oxygen-using equipment.

[0022] C. Oxygen storage in the oxygen storage tank: When the pressure in the oxygen storage tank is low and the oxygen supply flow rate at the downstream end is small, the control system will start the booster pump to pressurize the oxygen storage tank and store oxygen. The starting method of the booster pump is controlled by the pressure of the oxygen storage tank and the pressure of the buffer tank.

[0023] D. Control of the booster pump's start and stop: oxygenation is started only when the pressure in the oxygen storage tank is lower than the set minimum value, and oxygenation is stopped when it is higher than the set maximum value. Under the condition that the oxygen storage tank is in oxygenation mode, the booster pump is also controlled by the oxygen buffer pressure. The booster pump can only be started when the pressure in the buffer tank is higher than the set high value. When the pressure in the buffer tank is lower than the set low value, the booster pump stops working and waits for the pressure in the buffer tank to recover.

[0024] E. Depressurize before starting: Before each start of the booster pump, use the pressure relief valve to depressurize the booster outlet pressure. The depressurized oxygen enters the main pipeline or the buffer tank.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. In this invention, the oxygen supply source consists of multiple oxygen generating units or multiple oxygen generators. All oxygen generating units, booster pumps, and micro-boost pumps are controlled by a single control system, and all sensor signals are directly or indirectly fed back to the control system. Oxygen generated by all oxygen generating units or generators first enters a low-pressure buffer tank, with a pressure between 0 and 0.1 MPa. After the buffer tank, the oxygen is divided into two paths: one (main line) is directly fed into or via a micro-boost pump into the oxygen-enriched pipeline, and the other (bypass) passes through a booster pump and enters an oxygen storage tank. The maximum pressure of the oxygen storage tank can reach over 1 MPa, and it is used to store oxygen.

[0027] 2. This invention's control system detects information such as buffer tank pressure, oxygen storage tank pressure, and oxygen flow and pressure on the main pipeline, and calculates the operating time of each oxygen generating unit and booster pump. It automatically adjusts the number of oxygen generating units activated and whether to pressurize and store oxygen, ensuring that the operating time of each oxygen generator (or oxygen generating unit) is approximately the same. This ensures a long system lifespan, reduced energy consumption, good oxygen enrichment effect, and long oxygen delivery distance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] In the diagram: 1-Oxygen generator unit, 2-Buffer tank, 3-First pressure sensor, 4-First check valve, 5-Flow meter, 6-Pressure sensor, 7-Micro booster pump, 8-Second check valve, 9-Silencer chamber, 10-Booster pump, 11-Third check valve, 12-Fourth check valve, 13-Oxygen storage tank, 14-Second pressure sensor, 15-Pressure relief valve, 16-Oxygen replenishment valve. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1 In this embodiment of the invention, an energy-saving low-pressure PSA central oxygen enrichment system includes an oxygen generator unit 1 for preparing an oxygen source. The oxygen generator unit 1 consists of one or more oxygen generators, and each oxygen generator consists of one or more independent oxygen generating units.

[0032] It also includes a buffer tank 2 connected to the oxygen generator 1. The outlet of the buffer tank 2 is connected to the main oxygen supply pipeline, and the main oxygen supply pipeline is connected in series with a first one-way valve 4, a flow meter 5 and a pressure sensor 6.

[0033] The micro-increase mechanism, used for bypassing the main oxygen supply pipeline and increasing the oxygen source, is connected in parallel with the first one-way valve 4;

[0034] The main oxygen supply pipeline is connected to a booster pump unit via a three-way valve and a pipeline. The booster pump unit is connected to the air inlet of the oxygen storage tank 13. A fourth one-way valve 12 is connected in series between the booster pump unit and the oxygen storage tank 13.

[0035] If an oxygen supply pipe is connected between the main oxygen supply pipe and the outlet of the oxygen storage tank 13, then an oxygen supply valve 16 is connected in series on the oxygen supply pipe.

[0036] Each oxygen generation unit is supplied with compressed air by a DC compressor (controlled by an AC-to-DC drive board) or an AC compressor. Each unit comprises a gas separation unit consisting of a combination valve and two adsorption towers. Each unit is controlled by a main switch and can also be operated independently through a control system.

[0037] The oxygen buffer tank has a pressure range of 0 to 100 kPa (relative pressure, the same below), and the pressure sensor on it has a detection range of 0 to 100 kPa, with high detection accuracy within this range.

[0038] In this embodiment, a first pressure sensor 3 is installed on the buffer tank 2; a second pressure sensor 14 is connected in series on the oxygen storage tank 13.

[0039] In this embodiment, the micro-boosting mechanism includes a micro-boost pump 7, and a second one-way valve 8 and a silencer 9 are connected in series at the outlet end of the micro-boost pump 7.

[0040] In this embodiment, the pump set includes at least two booster pumps 10 connected in parallel, and a third check valve 11 is connected in series at the outlet of each booster pump 10.

[0041] In this embodiment, a pressure relief valve 15 is added to the outside of the pump unit. One end of the pressure relief valve 15 is connected to the main oxygen supply pipeline through a pipe, and the other end is connected to the front end of the fourth one-way valve 12.

[0042] In this embodiment, the pressure range of the buffer tank 2 is 0 to 100 kPa; the detection range of the first pressure sensor 3 covers 0 to 100 kPa.

[0043] In this embodiment, the oxygen supply pressure of the micro-increase mechanism is within 0.1 MPa; in special cases, it may exceed 0.1 MPa.

[0044] The control system can detect ambient pressure or manually input ambient pressure. Oxygen flow rate is calculated from the ambient pressure to standardize calculations within the control system and simplify decision-making criteria.

[0045] Each oxygen generation unit can automatically adjust its oxygen generation parameters based on ambient pressure to achieve optimal oxygen generation performance.

[0046] The number of oxygen generating units to be activated is determined by detecting the pressure in the oxygen buffer tank and the oxygen flow rate. During periods of low oxygen consumption, one or more oxygen generating units are shut down and in a resting state.

[0047] When oxygen demand is low or no oxygen is needed, turn on the pressurization system to fill the oxygen storage tank. During peak oxygen demand periods, open the oxygen replenishment valve behind the storage tank to achieve rapid oxygen enrichment.

[0048] An oxygen supply method for an energy-saving low-pressure PSA central oxygen-enrichment system includes the following steps:

[0049] A. Oxygen generation and supply: Oxygen generator 1 is supplied with compressed air by a DC compressor or an AC compressor; the oxygen generated by oxygen generator 1 is transported to buffer tank 2 for buffering; and then oxygen is supplied to the equipment through the main oxygen supply pipeline;

[0050] B. Micro-pressurized oxygen supply: The system determines whether the micro-pressurization mechanism needs to be intervened based on the length of the main oxygen supply pipeline and the pressure feedback from the pressure sensor 6. When intervention is required, the micro-pressurization pump 7 is turned on to pressurize the oxygen through a bypass. After being silenced by the silencer 9, the oxygen is delivered to the oxygen-using equipment.

[0051] C. Oxygen storage in oxygen storage tank 13: When the pressure of oxygen storage tank 13 is low and the downstream oxygen supply flow is small, the control system will start the booster pump 10 to pressurize oxygen storage tank 13; the starting method of booster pump 10 is controlled by the pressure of oxygen storage tank 13 and the pressure of buffer tank 2.

[0052] D. Control of the booster pump's start and stop: oxygenation is started only when the pressure of the oxygen storage tank 13 is lower than the set minimum value, and oxygenation is stopped when it is higher than the set maximum value; under the condition that oxygenation of the oxygen storage tank 13 is met, the booster pump 10 is also controlled by the oxygen buffer pressure. The booster pump can only be started when the pressure of the buffer tank 2 is higher than a certain value, and the booster pump 10 stops working when the pressure of the buffer tank is lower than a certain value, waiting for the pressure in the buffer tank 2 to recover;

[0053] E. Depressurize before starting: Before each start of the booster pump 10, use the pressure relief valve 15 to depressurize the booster outlet pressure. The depressurized oxygen enters the main pipeline or the buffer tank 12.

[0054] As a further explanation of the above embodiments, the pressure relief valve is opened 1 to 3 seconds before the booster is started, and the pressure relief valve is closed 0 to 5 seconds after the booster is started.

[0055] The system has settings for the initial number of oxygen generating units to be activated and the initial activation detection time after a power outage or during the first startup.

[0056] During the initial detection period, the control system detects oxygen flow and various pressures in real time to determine the number of oxygen generating units to be activated and whether to start pressurized oxygen storage.

[0057] This invention's control system detects information such as buffer tank pressure, oxygen storage tank pressure, and oxygen flow and pressure on the main pipeline, and calculates the operating time of each oxygen generating unit and booster pump. It automatically adjusts the number of oxygen generating units activated and whether to pressurize and store oxygen, ensuring that the operating time of each oxygen generator (or oxygen generating unit) is approximately the same. This ensures a long system lifespan, reduced energy consumption, good oxygen enrichment effect, and long oxygen delivery distance.

[0058] The important differences between this invention and traditional equipment, in addition to the contents already presented, are as follows: (1) This invention can ensure that the working time of each oxygen generator in the oxygen source is close, thereby avoiding some oxygen generators from running for a long time and being damaged, while other units are shut down for a long time and the parts fail; (2) Because of the presence of the micro-pressurization mechanism, each oxygen generator in the oxygen source can work in a low adsorption pressure state, reducing the outlet pressure of the compressor and thus reducing the working temperature of the compressor, extending the life of the compressor; (3) Automatically adjust the number of oxygen generators to be turned on, so that the oxygen generators will not start and stop frequently when the downstream oxygen consumption is relatively small; (4) When the pipeline pressure is detected to be large and the flow meter flow is very small, the entire system will stop after the oxygen storage tank reaches the pressure limit; (5) When the downstream oxygen consumption is small and the oxygen storage tank has sufficient pressure, only the oxygen storage tank supplies oxygen, avoiding the oxygen generators from running dry.

[0059] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0060] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An energy-saving low-pressure PSA central oxygen enrichment system, comprising an oxygen generator unit (1) for preparing an oxygen source, wherein the oxygen generator unit (1) consists of one or more oxygen generators, and each oxygen generator consists of one or more independent oxygen generating units, characterized in that: It also includes a buffer tank (2) connected to the oxygen generator (1), the outlet of which is connected to the main oxygen supply pipeline, and the main oxygen supply pipeline is connected in series with a first check valve (4), a flow meter (5) and a pressure sensor (6). The micro-increase mechanism, used for bypassing the main oxygen supply pipeline and increasing the oxygen source, is connected in parallel with the first one-way valve (4); The main oxygen supply pipeline is connected to a booster pump or multiple booster pumps in parallel through a three-way valve and a pipeline. The booster pump is connected to the air inlet of the oxygen storage tank (13). A fourth one-way valve (12) is connected in series between the booster pump and the oxygen storage tank (13). If an oxygen supply pipeline is connected between the main oxygen supply pipeline and the outlet of the oxygen storage tank (13), then an oxygen supply valve (16) is connected in series on the oxygen supply pipeline.

2. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: A first pressure sensor (3) is installed on the buffer tank (2); a second pressure sensor (14) is connected in series on the oxygen storage tank (13).

3. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: The micro booster mechanism includes a micro booster pump (7), with a second one-way valve (8) and a silencer chamber (9) connected in series at the outlet of the micro booster pump (7).

4. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: The pump set includes one or more booster pumps (10) connected in parallel, and each booster pump (10) has a third check valve (11) connected in series at its outlet.

5. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: If a pressure relief valve (15) is added to the outside of the pump unit, one end of the pressure relief valve (15) is connected to the main oxygen supply pipeline through a pipeline, and the other end is connected to the front end of the fourth check valve (12).

6. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: The pressure range of the buffer tank (2) is 0 to 100 kPa; the detection range of the first pressure sensor (3) is 0 to 100 kPa.

7. The energy-saving low-pressure PSA central oxygen enrichment system according to claim 1, characterized in that: The oxygen supply pressure of the micro-increase mechanism is within 0.1 MPa.

8. An oxygen supply method for an energy-saving low-pressure PSA central oxygen-enrichment system according to claim 1, characterized in that: Includes the following steps: A. Oxygen generation and supply: The oxygen generator (1) is supplied with compressed air by a DC compressor or an AC compressor. The oxygen generated by the oxygen generator (1) is transported to the buffer tank (2) for buffering; then oxygen is supplied to the equipment through the main oxygen supply pipeline; B. Micro-pressurized oxygen supply: The length of the main oxygen supply pipeline and the pressure feedback from the pressure sensor (6) determine whether the micro-pressurization mechanism needs to be intervened. When intervention is required, the micro-pressurization pump (7) is turned on to pressurize the oxygen through the bypass and deliver it to the oxygen-using equipment after being silenced by the silencer (9). C. Oxygen storage in oxygen storage tank (13): When the pressure of oxygen storage tank (13) is low and the oxygen supply flow rate at the downstream end is small, the control system will start the booster pump (10) to boost the oxygen storage tank (13) for oxygen storage; The starting method of booster pump (10) is controlled by the pressure of oxygen storage tank (13) and the pressure of buffer tank (2); D. Control of the start and stop of the booster pump: oxygenation is started when the pressure of the oxygen storage tank (13) is lower than the set low value, and oxygenation is stopped when it is higher than the set high value. Under the condition that oxygenation of the oxygen storage tank (13) is met, the booster pump (10) is also controlled by the oxygen buffer pressure. The booster pump can only be started when the pressure of the buffer tank (2) is higher than the set high value. When the pressure of the buffer tank is lower than the set low value, the booster pump (10) stops working and waits for the pressure in the buffer tank (2) to recover. E. Depressurize before starting: Before each start of the booster pump (10), use the pressure relief valve (15) to depressurize the booster outlet pressure. The depressurized oxygen enters the main pipeline or the buffer tank (12).

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