A pressure regulating system and method for micro-pressure oxygen chamber

Abstract

The present invention discloses a pressure regulating system and method for a micro-pressure oxygen chamber, including a gas mass flow meter, a pressure transmitter, a programmable controller, an exhaust electric valve, an intake electric valve, and a human-machine interface. The gas mass flow meter is connected to the RS485 communication interface of the programmable controller, and the pressure transmitter is connected to the analog input interface of the programmable controller; the analog output interface of the programmable controller is respectively connected to the exhaust electric valve and the intake electric valve, and the human-machine interface is connected to another communication interface of the programmable controller. The present invention can calculate the pressure increase, pressure stabilization and pressure reduction curves according to any set value; the programmable controller can ignore the pressure change interference caused by the slight leakage of the micro-pressure oxygen chamber itself by adopting PID control, so that the stability of the pressure increase and decrease and pressure stabilization process is not affected; the present invention has a smaller sampling period, which can make the pressure more stable and less volatile.

Description

Technical Field

[0001] The invention belongs to the technical field of oxygen chambers, and in particular relates to a pressure regulating system and method for a micro-pressure oxygen chamber. Background Art

[0002] The principle of pressure control in the microcompression oxygen chamber is: to inflate and pressurize the microcompression oxygen chamber through an oil-free compressor that meets the pressure bearing capacity of the microcompression oxygen chamber, and to adjust the air intake of the oil-free compressor or the exhaust volume of the microcompression oxygen chamber during the inflation and pressurization process, so that the microcompression oxygen chamber can reach the working pressure within the set time, and to ensure that the pressure of the microcompression oxygen chamber remains constant during the oxygen therapy time, thereby forming a safe and specific oxygen-rich atmosphere in the microcompression oxygen chamber. The pressure environment of the microcompression oxygen chamber is a process of boosting, stabilizing, and reducing pressure. Frequent fluctuations in pressure and the rates of boosting and reducing pressure will greatly affect the comfort of oxygen therapy personnel. Therefore, it is particularly important to provide a microcompression oxygen chamber with a pressure-stable, boosting, and reducing pressure-adjusting pressure-regulating system.

[0003] The boost control method of the existing micro-compression oxygen chamber basically uses an oil-free compressor for boosting. During the boost process, the air intake is controlled by controlling the frequent action of the solenoid valve or the exhaust volume of the micro-compression oxygen chamber is adjusted to control the boost and depressurization time. This control method has low accuracy, and the boost and depressurization rates of this control method are unstable and have large fluctuations. There are also obvious pressure fluctuations during the pressure stabilization process. Frequent pressure fluctuations will affect the comfort of oxygen therapy personnel in the micro-compression oxygen chamber. In addition, slight air leakage caused by the processing or assembly accuracy of the micro-compression oxygen chamber will also affect the stability of the boost and depressurization and pressure stabilization processes, making pressure stabilization control more difficult. Summary of the invention

[0004] The present invention aims at the above-mentioned problems, makes up for the deficiencies of the prior art, and provides a pressure regulating system and method for a micro-pressure oxygen chamber.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A pressure regulating system for a micro-pressure oxygen chamber comprises a gas mass flow meter, a pressure transmitter, a programmable controller, an exhaust electric valve, an intake electric valve, and a human-machine interface. The gas mass flow meter is connected to a communication interface of the programmable controller, and the pressure transmitter is connected to an analog input interface of the programmable controller; the analog output interface of the programmable controller is respectively connected to the exhaust electric valve and the intake electric valve, and the human-machine interface is connected to another communication interface of the programmable controller.

[0007] Furthermore, the programmable controller includes a flow closed-loop PID module, a pressure closed-loop PID module and a filter module. The signal output end of the gas mass flowmeter is connected to the flow closed-loop PID module through the filter module, the signal output end of the pressure transmitter is connected to the pressure closed-loop PID module through the filter module, the flow closed-loop PID module is connected to the intake electric valve, and the pressure closed-loop PID module is connected to the exhaust electric valve.

[0008] Furthermore, the programmable controller also includes a slope calculation module, and the slope calculation module is connected to the human-machine interface and the filter module respectively.

[0009] Furthermore, the exhaust electric valve and the intake electric valve are both miniature electric proportional ball valves.

[0010] Furthermore, the communication interface through which the gas mass flow meter is connected to the programmable controller is an RS485 communication interface.

[0011] A pressure regulating method for a micro-pressure oxygen chamber is implemented using the pressure regulating system for a micro-pressure oxygen chamber, and specifically comprises the following steps:

[0012] The user sets parameters in the human-machine interface, sets the pressure increase and decrease time T1 and T2 of the micro-compression oxygen chamber, the oxygen therapy time T and the oxygen therapy pressure P, and transmits the information to the programmable controller through the human-machine interface. The slope calculation module in the programmable controller calculates the standard pressure change curve according to the formula P=VT and the set value; in the formula P=VT, P is the pressure value of the micro-compression oxygen chamber, V is the pressure increase and decrease slope, and T is the time; at the same time, the average air intake can be calculated according to the actual volume of the micro-compression oxygen chamber;

[0013] The pressure transmitter reads the current pressure of the micro-pressure oxygen chamber in real time and feeds it back to the filter module of the programmable controller to filter the pressure value;

[0014] The gas mass flow meter reads the current air intake flow of the micro-pressure oxygen chamber in real time and feeds it back to the filter module of the programmable controller to filter the flow value.

[0015] Furthermore, the pressure closed-loop PID module in the programmable controller compares the pressure value read by the pressure transmitter with the pressure at different times of the calculated pressure change curve, and can perform PID closed-loop adjustment for a period of time, so that the actual pressure of the micro-compression oxygen chamber is adjusted according to the calculated standard pressure change curve, and the calculated adjustment value is sent to the exhaust electric valve, and the exhaust electric valve is controlled to change the opening size according to the received control instruction, so as to change the exhaust volume of the micro-compression oxygen chamber, thereby achieving the purpose of controlling the actual pressure of the micro-compression oxygen chamber; wherein, since the pressure of the micro-compression oxygen chamber is inversely proportional to the exhaust volume of the micro-compression oxygen chamber, the gain parameter in the pressure closed-loop PID module is a negative number.

[0016] Furthermore, the flow closed-loop PID module in the programmable controller compares the flow value read by the gas mass flowmeter with the average air intake volume calculated in the slope calculation module, and can perform PID closed-loop adjustment, so that the actual air intake volume of the micro-compression oxygen chamber is adjusted according to the calculated average air intake volume, and the adjustment value is sent to the air intake electric valve, and the air intake electric valve controls the change of the opening size according to the received control instruction, changes the air intake volume of the micro-compression oxygen chamber, and thus achieves the purpose of controlling the actual air intake flow rate of the micro-compression oxygen chamber; wherein, since the pressure of the micro-compression oxygen chamber is proportional to the air intake volume of the micro-compression oxygen chamber, the gain parameter in the flow closed-loop PID module is a positive number.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The pressure regulating system for the micro-pressure oxygen chamber provided by the present invention has a simple composition and connection method of the entire pressure regulating system.

[0019] 2. The present invention can calculate the voltage boost, voltage stabilization and voltage reduction curves according to any set value.

[0020] 3. The programmable controller of the present invention can ignore the pressure change interference caused by slight air leakage of the micro-pressure oxygen chamber itself by adopting PID control, so that the stability of the pressure increase and decrease and pressure stabilization process is not affected.

[0021] 4. The present invention has a shorter sampling period, which can make the pressure more stable and less volatile. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a structural schematic block diagram of a pressure regulating system for a micro-pressure oxygen chamber.

[0023] Figure 2 The present invention is a control flow chart of a pressure regulating system for a micro-pressure oxygen chamber.

[0024] Figure 3 The present invention is a pressure change curve diagram of a micro-pressure oxygen chamber after pressure regulation using a pressure regulation system for the micro-pressure oxygen chamber of the present invention.

[0025] In the figure: 1 is a pressure transmitter; 2 is a programmable controller; 3 is an exhaust electric valve; 4 is a human-machine interface; 5 is a gas mass flow meter; and 6 is an intake electric valve. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figures 1 to 3 As shown, an embodiment of the present invention provides a pressure regulating system for a micro-pressure oxygen chamber, including a gas mass flow meter 5, a pressure transmitter 1, a programmable controller 2, an exhaust electric valve 3, an intake electric valve 6, and a human-machine interface 4, wherein the gas mass flow meter 5 is connected to the RS485 communication interface of the programmable controller 2, and the pressure transmitter 1 is connected to the analog input interface of the programmable controller 2; the analog output interface of the programmable controller 2 is respectively connected to the exhaust electric valve 3 and the intake electric valve 6, and the human-machine interface 4 is connected to another communication interface of the programmable controller 2; wherein the exhaust electric valve 3 and the intake electric valve 6 are used to be connected to the micro-pressure oxygen chamber.

[0028] The programmable controller 2 is composed of a flow closed-loop PID module, a pressure closed-loop PID module, a filtering module and a slope calculation module. The signal output end of the gas mass flowmeter 5 is connected to the flow closed-loop PID module through the filtering module, the signal output end of the pressure transmitter 1 is connected to the pressure closed-loop PID module through the filtering module, the flow closed-loop PID module is connected to the intake electric valve 6, the pressure closed-loop PID module is connected to the exhaust electric valve 3, and the slope calculation module is respectively connected to the human-machine interface 4 and the filtering module.

[0029] The exhaust electric valve 3 and the intake electric valve 6 are both miniature electric proportional ball valves.

[0030] Specifically, the pressure transmitter 1 is a high-precision pressure transmitter with an accuracy level of 0.2 and a response time of ≤50ms. The range of the pressure transmitter 1 is selected according to the pressure bearing capacity of the micro-compression oxygen chamber. The pressure transmitter 1 is used to accurately detect the real-time pressure of the micro-compression oxygen chamber and feed it back to the filter module of the programmable controller 2. The filter module filters the real-time pressure value data detected by the pressure transmitter 1 to make the detected data true and reliable; the programmable controller 2 is responsible for calculating the slope of the micro-compression oxygen chamber pressure increase and decrease and the centralized control of PID regulation output; the exhaust electric valve 3 is a micro-electric proportional ball valve using analog control, which is used to receive control instructions from the programmable controller 2. The exhaust volume of the micro-compression oxygen chamber is controlled; the human-machine interface 4 is used to set the oxygen therapy pressure and the boost and decompression time of the micro-compression oxygen chamber, and display the pressure change curve of the micro-compression oxygen chamber; the air intake electric valve 6 is a micro-electric proportional ball valve using analog control, which is used to receive the control instruction of the programmable controller 2 to control the air intake volume of the micro-compression oxygen chamber; the gas mass flowmeter 5 is a high-precision instrument equipment for detecting gas flow and component composition. In this embodiment, it is used to detect the gas flow and oxygen content entering the micro-compression oxygen chamber. The gas mass flowmeter 5 reads the current air intake flow of the micro-compression oxygen chamber in real time and feeds it back to the filtering module of the programmable controller 2, and filters the flow value to make the read data true and reliable.

[0031] The working principle of the pressure regulating system for the micro-compression oxygen chamber of the present invention is described as follows: the ideal pressure increase, pressure stabilization and pressure reduction curves are calculated according to the set values ​​of the user in the human-machine interface 4, so as to infer the pressure regulation target at the next moment, and the opening size of the exhaust electric valve 3 is controlled by the pressure closed-loop PID module of the programmable controller 2, so as to control the exhaust volume of the micro-compression oxygen chamber; the opening size of the intake electric valve 6 is controlled by the flow closed-loop PID module of the programmable controller 2, so as to control the intake volume of the micro-compression oxygen chamber; the actual pressure value change process of the micro-compression oxygen chamber is achieved to be consistent with the calculated pressure increase, pressure stabilization and pressure reduction curves.

[0032] The pressure regulating method for a micro-pressure oxygen chamber of the present invention comprises the following steps: Figure 2 As shown in the control flow chart, the user sets parameters in the human-machine interface 4, sets the pressure rise and pressure fall time T1, T2, oxygen therapy time T and oxygen therapy pressure P of the micro-compression oxygen chamber, and transmits the information to the programmable controller 2 by the human-machine interface 4. The slope calculation module in the programmable controller 2 calculates the standard pressure change curve according to the formula P=VT (P is the pressure value of the micro-compression oxygen chamber, V is the pressure rise and pressure fall slope, and T is time), and calculates the standard pressure change curve according to the set value, as shown in FIG. Figure 3As shown; at the same time, the average air intake volume can be calculated according to the actual volume of the micro-compression oxygen chamber. The pressure transmitter 1 reads the current pressure of the micro-compression oxygen chamber in real time and feeds it back to the filter module of the programmable controller 2, and filters the pressure value to make the read data true and reliable. The gas mass flowmeter 5 reads the current air intake flow of the micro-compression oxygen chamber in real time and feeds it back to the filter module of the programmable controller 2, and filters the flow value to make the read data true and reliable.

[0033] The pressure closed-loop PID module in the programmable controller 2 compares the pressure value read by the pressure transmitter 1 with the pressure at different times of the calculated pressure change curve, and can perform PID closed-loop adjustment for a period of time, so that the actual pressure of the micro-compression oxygen chamber is adjusted according to the calculated standard pressure change curve, and the calculated adjustment value is sent to the exhaust electric valve 3. The exhaust electric valve 3 controls the change of the opening size according to the received control instruction, changes the exhaust volume of the micro-compression oxygen chamber, and thus achieves the purpose of controlling the actual pressure of the micro-compression oxygen chamber. Since the pressure of the micro-compression oxygen chamber is inversely proportional to the exhaust volume of the micro-compression oxygen chamber, the gain parameter in the pressure closed-loop PID module is a negative number.

[0034] The flow closed-loop PID module in the programmable controller 2 compares the flow value read by the gas mass flow meter 5 with the average air intake calculated in the slope calculation module, and can perform PID closed-loop adjustment, so that the actual air intake of the micro-compression oxygen chamber is adjusted according to the calculated average air intake, and the adjustment value is sent to the air intake electric valve 6. The air intake electric valve 6 controls the change of the opening size according to the received control instruction, changes the air intake of the micro-compression oxygen chamber, and thus achieves the purpose of controlling the actual air intake flow of the micro-compression oxygen chamber. Since the pressure of the micro-compression oxygen chamber is proportional to the air intake of the micro-compression oxygen chamber, the gain parameter in the flow closed-loop PID module is a positive number.

[0035] Through the two-way PID closed-loop control in the programmable controller 2, the dual adjustment of the intake and exhaust of the micro-compression oxygen chamber can accurately correct the pressure fluctuation of the micro-compression oxygen chamber to achieve the purpose of pressure stabilization. In addition, the gas mass flowmeter 5 also has the function of detecting the intake gas composition of the micro-compression oxygen chamber, detecting the intake air flow rate and the intake oxygen content at the same time, which has a positive effect on calculating the oxygen concentration in the micro-compression oxygen chamber.

[0036] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pressure regulating method for a micro-pressure oxygen chamber, characterized in that: It is realized by a pressure regulating system for a micro-pressure oxygen chamber, the pressure regulating system includes a gas mass flow meter, a pressure transmitter, a programmable controller, an exhaust electric valve, an intake electric valve, and a human-machine interface, the gas mass flow meter is connected to a communication interface of the programmable controller, and the pressure transmitter is connected to the analog input interface of the programmable controller; the analog output interface of the programmable controller is respectively connected to the exhaust electric valve and the intake electric valve, and the human-machine interface is connected to another communication interface of the programmable controller; the programmable controller includes a flow closed-loop PID module, a pressure closed-loop PID module and a filter module, the signal output end of the gas mass flow meter is connected to the flow closed-loop PID module through the filter module, the signal output end of the pressure transmitter is connected to the pressure closed-loop PID module through the filter module, the flow closed-loop PID module is connected to the intake electric valve, and the pressure closed-loop PID module is connected to the exhaust electric valve; the programmable controller also includes a slope calculation module, and the slope calculation module is respectively connected to the human-machine interface and the filter module; The pressure regulation method specifically includes the following steps: the user sets parameters in the human-machine interface, sets the pressure increase and pressure decrease time T1 and T2 of the micro-compression oxygen chamber, the oxygen therapy time T and the oxygen therapy pressure P, and the human-machine interface transmits the information to the programmable controller, and the slope calculation module in the programmable controller calculates the standard pressure change curve according to the formula P=VT and the set value; in the formula P=VT, P is the pressure value of the micro-compression oxygen chamber, V is the pressure increase and pressure decrease slope, and T is time; at the same time, the average air intake volume can be calculated according to the actual volume of the micro-compression oxygen chamber; the pressure transmitter reads the current pressure of the micro-compression oxygen chamber in real time and feeds it back to the filter module of the programmable controller, and the pressure value is filtered; the gas mass flowmeter reads the current air intake flow of the micro-compression oxygen chamber in real time and feeds it back to the filter module of the programmable controller, and the flow value is filtered.

2. A pressure regulating method for a micro-pressure oxygen chamber according to claim 1, characterized in that: The exhaust electric valve and the intake electric valve both adopt micro electric proportional ball valves.

3. A pressure regulating method for a micro-pressure oxygen chamber according to claim 1, characterized in that: The communication interface connecting the gas mass flow meter to the programmable controller is an RS485 communication interface.

4. A pressure regulating method for a micro-pressure oxygen chamber according to claim 1, characterized in that: The pressure closed-loop PID module in the programmable controller compares the pressure value read by the pressure transmitter with the pressure at different times of the calculated pressure change curve, and can perform PID closed-loop adjustment for a period of time, so that the actual pressure of the micro-compression oxygen chamber is adjusted according to the calculated standard pressure change curve, and the calculated adjustment value is sent to the exhaust electric valve, and the exhaust electric valve is controlled to change the opening size according to the received control instruction, and the exhaust volume of the micro-compression oxygen chamber is changed, thereby achieving the purpose of controlling the actual pressure of the micro-compression oxygen chamber; Since the pressure of the micro-compression oxygen chamber is inversely proportional to the exhaust volume of the micro-compression oxygen chamber, the gain parameter in the pressure closed-loop PID module is a negative number.

5. A pressure regulating method for a micro-pressure oxygen chamber according to claim 1, characterized in that: The flow closed-loop PID module in the programmable controller compares the flow value read by the gas mass flow meter with the average air intake calculated in the slope calculation module, and can perform PID closed-loop adjustment, so that the actual air intake of the micro-compression oxygen chamber is adjusted according to the calculated average air intake, and the adjustment value is sent to the air intake electric valve, and the air intake electric valve is controlled to change the opening size according to the received control instruction, and the air intake volume of the micro-compression oxygen chamber is changed, thereby achieving the purpose of controlling the actual air intake flow of the micro-compression oxygen chamber; Since the pressure of the micro-compression oxygen chamber is proportional to the air intake of the micro-compression oxygen chamber, the gain parameter in the flow closed-loop PID module is a positive number.

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