Oxygen concentration measuring device and method for inerting system

Abstract

The invention discloses an oxygen concentration measuring device and method for an inerting system, and the device comprises an oxygen partial pressure sensor, a pressure sensor, a signal processing module, a pressure reduction assembly (1) which is disposed at the gas inlet end of the oxygen concentration measuring device and is used for reducing the gas pressure to a preset pressure value, and a sizing hole (2) which is disposed at the gas outlet end of the oxygen concentration measuring device. And a filter screen (3) is arranged in front of the sizing hole. The pressure reduction assembly is arranged at the gas inlet end, the sizing hole is formed in the gas outlet end, the oxygen concentration measurement precision of nitrogen-rich gas in an inerting system can be improved, the filter screen is arranged in front of the sizing hole, and dust in a cabin can be prevented from entering the device from the gas outlet end and being attached to an oxygen partial pressure sensor when the oxygen concentration measurement device stands. And the service life of the oxygen partial pressure sensor in the oxygen concentration measuring device can be prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation airborne inerting, and in particular relates to an oxygen concentration measuring device and method for an inerting system. Background Art

[0002] At present, the airborne inerting system is used for fuel tank inerting, and nitrogen-rich gas is generated by an air separation device to protect the fuel tank. The oxygen concentration in the nitrogen-rich gas needs to be measured in the system. The current oxygen concentration measuring device measures the oxygen pressure in the nitrogen-rich gas through an oxygen partial pressure sensor, and then measures the total gas pressure of the nitrogen-rich gas through a pressure sensor. The signal processing module calculates the ratio of the oxygen pressure and the total gas pressure to obtain the oxygen concentration of the current gas. However, the current oxygen concentration measuring device has the following two problems: First, the measurement accuracy of the oxygen partial pressure sensor is low, and it is currently impossible to directly improve the measurement accuracy of the oxygen partial pressure sensor to meet the oxygen concentration measurement accuracy of nitrogen-rich gas; second, the oxygen partial pressure sensor has a short service life, and the oxygen partial pressure sensor in the oxygen concentration measuring device needs to be replaced regularly. Due to the technical limitations of the oxygen partial pressure sensor, how to improve the oxygen concentration measurement accuracy of nitrogen-rich gas and the service life of the oxygen partial pressure sensor in the oxygen concentration measuring device are technical problems that have not been solved by the oxygen concentration measuring device of the airborne inerting system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an oxygen concentration measuring device and method for an inerting system, so as to improve the oxygen concentration measuring accuracy of the oxygen concentration measuring device of the airborne inerting system and to increase the service life of the oxygen partial pressure sensor in the oxygen concentration measuring device.

[0004] The technical problem to be solved by the present invention can be achieved by the following technical solution. The present invention provides an oxygen concentration measuring device for an inerting system, comprising: a rectangular shell; the rectangular shell is provided with:

[0005] Oxygen partial pressure sensor, used to measure the oxygen pressure in nitrogen-rich gas;

[0006] A pressure sensor for measuring the total gas pressure of the nitrogen-rich gas;

[0007] The signal processing module is used to calculate the ratio of oxygen pressure to total gas pressure to obtain the oxygen concentration of the current gas;

[0008] The rectangular shell surface is provided with:

[0009] A decompression component 1, arranged at the air inlet end of the oxygen concentration measuring device, for reducing the gas pressure to a predetermined pressure value;

[0010] The sizing hole 2 is arranged at the gas outlet end of the oxygen concentration measuring device, and a filter screen 3 is arranged in front of the sizing hole.

[0011] Optionally, the predetermined pressure value is 230 kPa to 300 kPa.

[0012] Optionally, the calibrating hole 2 limits the gas flow rate to 0.2-0.5 L / min.

[0013] Optionally, the calibrating hole 2 limits the gas flow rate to 0.5 L / min.

[0014] Optionally, the pore size of the filter 3 is not greater than 0.5 microns.

[0015] Optionally, the rear end of the sizing hole 2 is elliptical.

[0016] Optionally, the calibrating hole 2 is elliptical.

[0017] The present invention also provides a method for measuring oxygen concentration in an inerting system, using the device described in any one of the above, the method comprising:

[0018] An oxygen partial pressure sensor is used to measure the oxygen pressure in nitrogen-rich gas;

[0019] A pressure sensor is used to measure the total pressure of the nitrogen-rich gas;

[0020] Obtain the oxygen concentration of the current gas based on the ratio of oxygen pressure to total gas pressure.

[0021] The present invention provides an oxygen concentration measuring device and method for an inerting system. By arranging a decompression component at the air inlet end and arranging a sizing hole at the air outlet end, the oxygen concentration measurement accuracy of nitrogen-rich gas in the inerting system can be improved. By arranging a filter in front of the sizing hole, dust in the cabin can be prevented from entering the device from the air outlet end and adhering to the oxygen partial pressure sensor when the oxygen concentration measuring device is stationary, thereby increasing the service life of the oxygen partial pressure sensor in the oxygen concentration measuring device. In addition, by adjusting the decompression interval of the decompression component, the oxygen concentration measuring device of the airborne inerting system can be applied to more working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 is an outline diagram of an oxygen concentration measuring device;

[0024] Description of reference numerals:

[0025] 1- Pressure relief assembly;

[0026] 2-Sizing hole;

[0027] 3-Filter. DETAILED DESCRIPTION

[0028] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with the embodiments. The following text is only used to describe one or several specific implementations of the present invention, and does not strictly limit the protection scope of the specific claims of the present invention.

[0029] The inerting system oxygen concentration measuring device and method provided by the present invention are explained below in conjunction with the accompanying drawings.

[0030] The original airborne inerting system oxygen concentration measuring device is equipped with a calibrating hole at the air inlet end, through which the gas flow is limited to 0.5L / min, and the high-pressure nitrogen-rich gas at the air inlet end is reduced to the same pressure as the cabin pressure to ensure that the gas pressure in the oxygen concentration measuring device does not exceed the upper limit of the oxygen partial pressure sensor. The original device has an oxygen concentration measurement accuracy of only ±1% (absolute value) because the measured gas pressure is consistent with the cabin pressure, and the cabin pressure is low.

[0031] To solve this problem, the present invention provides an oxygen concentration measuring device for an inerting system. Figure 1 The figure is the appearance diagram of the oxygen concentration measuring device of the present invention. The oxygen concentration measuring device of the present invention comprises: an oxygen partial pressure sensor for measuring the oxygen pressure in the nitrogen-rich gas; a pressure sensor for measuring the total gas pressure of the nitrogen-rich gas; a signal processing module for calculating the ratio of the oxygen pressure to the total gas pressure to obtain the oxygen concentration of the current gas, and also comprises: a decompression component 1 arranged at the air inlet end of the oxygen concentration measuring device to reduce the gas pressure to a predetermined pressure value, a sizing hole 2 arranged at the air outlet end of the oxygen concentration measuring device, and a filter 3 arranged in front of the sizing hole 2.

[0032] The predetermined pressure value is generally 230 kPa to 300 kPa. The calibrated hole limits the gas flow rate to 0.2 to 0.5 L / min. The pore size of the filter is not greater than 0.5 microns.

[0033] In this embodiment, by removing the calibrating hole currently set at the air inlet end of the oxygen concentration measuring device, and adding a calibrating hole 2 with a flow rate of 0.5L / min at the air outlet end of the oxygen concentration measuring device, in this case, the gas pressure value in the oxygen concentration measuring device can be kept consistent with the air inlet end. However, at this time, the internal air pressure of the oxygen concentration measuring device is too high, which will cause the oxygen partial pressure sensor to fail. For this reason, a decompression component 1 is added to the air inlet end, and the air inlet pressure of generally 300kPa~700kPa is reduced to 230kPa~300kPa through the decompression component. Keeping the internal air pressure of the oxygen concentration measuring device at 230kPa~300kPa can improve the measurement accuracy of oxygen concentration to ±0.25% (absolute value), and the measurement accuracy is not affected by the cabin air pressure. The decompression component 1 can use a commonly used decompression device, and there are no special requirements.

[0034] In addition, adding a filter 3 at the air outlet can prevent dust in the cabin from entering the device and adhering to the oxygen partial pressure sensor when the oxygen concentration measuring device is stationary, thereby increasing the service life of the oxygen partial pressure sensor.

[0035] Optionally, the sizing hole 2 is an elliptical hole.

[0036] Optionally, the rear end of the sizing hole 2 is elliptical.

[0037] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. An oxygen concentration measuring device for an inerting system, characterized in that: include: Rectangular shell; the rectangular shell is provided with: Oxygen partial pressure sensor, used to measure the oxygen pressure in nitrogen-rich gas; A pressure sensor for measuring the total gas pressure of the nitrogen-rich gas; The signal processing module is used to calculate the ratio of oxygen pressure to total gas pressure to obtain the oxygen concentration of the current gas; The rectangular shell surface is provided with: A decompression component (1), arranged at the air inlet end of the oxygen concentration measuring device, for reducing the gas pressure to a predetermined pressure value; A sizing hole (2) is arranged at the gas outlet end of the oxygen concentration measuring device, and a filter screen (3) is arranged in front of the sizing hole.

2. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The predetermined pressure value is 230 kPa to 300 kPa.

3. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The calibrating hole (2) limits the gas flow rate to 0.2-0.5 L / min.

4. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The calibrated hole (2) limits the gas flow rate to 0.5 L / min.

5. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The pore size of the filter (3) is no greater than 0.5 micrometers.

6. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The calibrating hole (2) is elliptical.

7. The oxygen concentration measuring device for an inerting system according to claim 1, characterized in that: The rear end of the calibrating hole (2) is elliptical.

8. A method for measuring oxygen concentration in an inerting system, characterized in that: Using the device according to any one of claims 1 to 7, the method comprises: An oxygen partial pressure sensor is used to measure the oxygen pressure in nitrogen-rich gas; A pressure sensor is used to measure the total pressure of the nitrogen-rich gas; Obtain the oxygen concentration of the current gas based on the ratio of oxygen pressure to total gas pressure.

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