Oil mist detector and detection method

Abstract

An oil mist detector comprises a shell which is of a cavity structure and forms a containing space, the front face of the shell is provided with an air inlet, the back face of the shell is provided with an air outlet, and the air inlet and the air outlet are coaxially arranged to form a linear airflow channel; each detection assembly comprises an infrared emitter which is arranged on one side of the linear airflow channel and emits infrared light beams to the oil mist particles flowing through the linear airflow channel; the first photodiode is perpendicular to the infrared beam emission direction, is arranged close to the air outlet end and is used for receiving scattered light signals generated when the oil mist particles are irradiated by the infrared beams; the second photodiode is arranged on the other side of the linear airflow channel, is coaxially opposite to the infrared transmitter and is used for receiving the light source intensity of the infrared transmitter; and the main control circuit board is arranged in the shell and is isolated from the area where the plurality of detection assemblies are located through a physical isolation structure. The invention further provides an oil mist detection method, the oil mist concentration is inversed by detecting the scattering intensity of the oil mist particles to the light beams, the measurement precision is extremely high, and the advantages are obvious.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil mist detection, and particularly relates to an oil mist detector and a detection method. BACKGROUND

[0002] During the operation of a diesel engine, oil mist may be generated in the crankcase, and when the concentration of the oil mist reaches a certain threshold, there is an explosion risk.

[0003] The existing oil mist detectors generally have the following defects: first, the gas chamber is designed unreasonably, resulting in large airflow resistance, and oil mist particles are easily attached to the sensor wall, causing detection errors and frequent maintenance; second, oil film pollutes the optical window, causing signal attenuation and precision decline, and frequent cleaning or calibration is required; third, the system has low integration, the circuit and software design are complex, the failure rate is high, the maintenance cost is large, and real-time and high-precision monitoring is difficult to achieve.

[0004] Therefore, it is necessary to provide an oil mist detector with compact structure, strong anti-pollution and high reliability to overcome the above problems.

[0005] It can be understood that the above statements only provide background technology related to the present application, and do not necessarily constitute prior art. SUMMARY

[0006] The purpose of the present application is to provide an oil mist detector and a detection method for realizing high-precision and low-maintenance oil mist concentration monitoring.

[0007] In order to achieve the above object, the first aspect of the present application provides an oil mist detector, comprising: a shell, which is internally a cavity structure, forms a containing space, and is provided with an air inlet on the front surface and an air outlet on the back surface, the air inlet and the air outlet are coaxially arranged to form a straight airflow channel; a plurality of detection assemblies arranged in the interior of the shell, comprising: an infrared emitter arranged on one side of the straight airflow channel in the interior of the shell, for emitting an infrared light beam to the oil mist particles flowing through the straight airflow channel; a first photodiode arranged vertically to the direction of the infrared light beam emission and close to one end of the air outlet, for receiving the scattering light signal generated by the oil mist particles irradiated by the infrared light beam; a second photodiode arranged on the other side of the straight airflow channel in the interior of the shell and coaxially opposite to the infrared emitter, for receiving the light source intensity of the infrared emitter; a main control circuit board arranged in the interior of the shell and isolated from the area where the plurality of detection assemblies are located by a physical isolation structure, so that the oil mist particles cannot contact the main control circuit board; wherein the main control circuit board is connected to each of the detection assemblies by wires and is configured to: process the scattering light signal received by the first photodiode, convert it into a first electric signal and calculate the oil mist concentration data; determine whether the oil mist concentration is greater than or equal to a first threshold value, and trigger an oil mist alarm when it is greater than or equal to the first threshold value; receive the light source intensity signal received by the second photodiode, convert it into a second electric signal and determine the light source intensity; determine whether the second electric signal is greater than or equal to a second threshold value, and trigger an infrared emitter abnormal operation alarm when it is less than the second threshold value.

[0008] Preferably, the air inlet and the air outlet are both louver structures.

[0009] Preferably, the wavelength of the infrared light emitted by the infrared emitter matches the diameter of the oil mist particles, which is 1-10 μm.

[0010] Preferably, the infrared emitter, the first photodiode and the second photodiode are all sealed in independent cavities, each cavity is fixed to the inner wall of the shell, and one side of each cavity facing the straight airflow channel is provided with an optical window.

[0011] Preferably, the optical window is an oil-proof window sheet made of quartz material and covered with a coating having an oil mist adhesion prevention property.

[0012] Preferably, the oil mist detector further comprises a fan arranged at the end of the air outlet, connected to the main control circuit board and controlled to be turned on or off by the main control circuit board; wherein the fan is used to suck the oil mist particles from the air inlet into the interior of the shell and make the oil mist particles accelerate and flow straight along the direction from the air inlet to the air outlet.

[0013] Preferably, the oil mist detector further comprises a three-color indicator lamp arranged on the surface of the shell and connected with the main control circuit board; wherein the first indicator lamp color is used to indicate the normal working state, the second indicator lamp color is used to indicate the abnormality when the light source intensity is less than the second threshold value, and the third indicator lamp color is used to indicate the alarm when the oil mist concentration exceeds the first threshold value.

[0014] Preferably, the oil mist detector further comprises an audible and visual alarm arranged on the surface of the shell and connected with the main control circuit board; wherein the audible and visual alarm is triggered to alarm when the main control circuit board judges that the oil mist concentration is greater than or equal to the first threshold value.

[0015] Preferably, the oil mist detector further comprises an externally arranged oil mist detection panel connected with the main control circuit board and used to receive the oil mist data transmitted by the main control circuit board or to control the main control circuit board; wherein the oil mist detection panel comprises a human-computer interaction interface configured to allow the user to input control instructions, to display the graphical oil mist concentration data in real time, to query the historical concentration records, and to provide a data storage function.

[0016] The second aspect of the present application provides an oil mist detection method, which is realized by using the oil mist detector and comprises the following steps: S1, the oil mist detector is started, the main control circuit board drives the fan to work, air containing oil mist particles is sucked into the inside of the shell from the air inlet, and the oil mist particles flow straight from the air inlet to the air outlet; S2, the main control circuit board drives the infrared emitter to emit an infrared light beam; S3, the second photodiode receives the infrared light beam and converts it into a second electric signal reflecting the light source intensity and transmits it to the main control circuit board; the main control circuit board uses the second electric signal transmitted by the second photodiode to judge whether the second electric signal is greater than or equal to the second threshold value; wherein if the second electric signal is less than the second threshold value, the second indicator lamp is triggered to light up, and the infrared emitter is triggered to work abnormally to alarm; S4, the first photodiode receives the scattered light signal and converts it into a first electric signal and transmits it to the main control circuit board; the main control circuit board uses the first electric signal transmitted by the first photodiode to calculate the real-time oil mist concentration and judges whether the oil mist concentration is greater than or equal to the first threshold value; wherein if the oil mist concentration is greater than or equal to the first threshold value, the third indicator lamp is triggered to light up, and the alarm is triggered to alarm.

[0017] Compared with the prior art, the oil mist detector and detection method provided by the present application have at least the following beneficial effects: (1) The present application is based on the light scattering principle, and the oil mist concentration is inversely calculated by detecting the scattering intensity of the light beam by the oil mist particles, so that the measurement accuracy is extremely high; (2) The application detects the light source intensity emitted by the infrared emitter through the design of the first photodiode, effectively solves the problems of infrared emitter failure or aging, and has great practical value; (3) The materials used in the application are oil mist adhesion resistant materials, have strong anti-pollution ability, greatly improve the service life of the oil mist detector, and significantly reduce the equipment maintenance frequency and cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is an internal structure diagram of the oil mist detector in the application; Figure 2 is a principle diagram of the detection assembly of the oil mist detector in the application.

[0019] In the drawings: 1 - shell, 11 - air inlet, 12 - air outlet, 2 - detection assembly, 21 - infrared emitter, 22 - first photodiode, 23 - second photodiode, 3 - main control circuit board, 4 - fan. DETAILED DESCRIPTION

[0020] The application will be further described below in conjunction with the accompanying drawings. Figure 1 to the accompanying drawings, Figure 2 A preferred specific embodiment is described in detail, and the application is further described.

[0021] It should be noted that the drawings are greatly simplified and all use non-precise proportions, only to facilitate and clarify the purpose of assisting in the description of the embodiments of the application, and are not used to limit the conditions of the implementation of the application, so they do not have technical substantive significance, any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the application, should still fall within the scope of the technical content disclosed by the application.

[0022] It should be noted that in the application, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes the explicitly listed elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0023] As shown in Figure 1 and Figure 2 , the first aspect of the application provides an oil mist detector, comprising: A shell 1, which is internally a cavity structure, forms a containing space, and its front surface is provided with an air inlet 11, and its back surface is provided with an air outlet 12, the air inlet 11 and the air outlet 12 are coaxially arranged to form a straight airflow channel; A plurality of detection components 2 are arranged in the shell 1 for detecting oil mist particles, comprising: An infrared emitter 21 is arranged on one side of the straight airflow channel in the shell 1 for emitting an infrared light beam to the oil mist particles flowing through the straight airflow channel; A first photodiode 22 is arranged vertically to the direction of the infrared light beam and close to one end of the air outlet 12 for receiving the scattering light signal generated by the oil mist particles irradiated by the infrared light beam; A second photodiode 23 is arranged on the other side of the straight airflow channel in the shell 1 and coaxially opposite to the infrared emitter 21 for receiving the light source intensity signal of the infrared emitter 21; A main control circuit board 3 is arranged in the shell 1 and is isolated from the area where the plurality of detection components 2 are located by a physical partition structure, so that the oil mist particles cannot contact the main control circuit board 3.

[0024] The main control circuit board 3 is connected to each of the detection components 2 by wires and is configured to: Receive the scattering light signal received by the first photodiode 22, convert it into a first electric signal and calculate the oil mist concentration; Determine whether the oil mist concentration is greater than or equal to a first threshold value, and trigger an oil mist alarm when it is greater than or equal to the first threshold value; Receive the light source intensity signal received by the second photodiode 23, convert it into a second electric signal and determine the light source intensity; Determine whether the second electric signal is greater than or equal to a second threshold value, and trigger an infrared emitter 21 abnormal operation alarm when it is less than the second threshold value.

[0025] It should be noted that the physical partition structure preferably adopts a sealing partition plate, which can divide the cavity structure inside the shell 1 into two independent chambers, i.e. the plurality of detection components 2 are located in the same chamber, and the main control circuit board 3 is located in the other chamber. It can be understood that at this time, the sealing partition plate and the inner wall of the shell 1 are connected in airtightness by a rubber sealing ring; at the same time, the main control circuit board 3 is connected to each of the detection components 2 by wires, therefore, when the wires pass through the sealing partition plate, the contact surfaces between the two are also provided with a rubber sealing ring to realize airtight connection, so as to prevent the oil mist from polluting the main control circuit board 3.

[0026] In the preferred embodiment of the present application, the air inlet 11 and the air outlet 12 are both in louver structure, which is used to prevent the outside light from interfering with the oil mist detection scattered light; the inner wall of the shell 1 is made of flame-retardant material, and is coated with a coating with oil mist adhesion prevention property, so as to reduce the oil mist particle deposition and improve the safety. Preferably, the flame-retardant material is glass fiber reinforced polyamide, and the coating is fluorosilicon nano composite coating.

[0027] Further, the wavelength of the infrared light emitted by the infrared emitter 21 matches the diameter of the oil mist particles, which is preferably 1-10 μm.

[0028] It should be noted that the infrared emitter 21, the first photodiode 22 and the second photodiode 23 are respectively sealed and fixed in an independent cavity, and the cavity is fixedly installed on the inner wall of the shell 1. Wherein, one side of each cavity facing the detection area (i.e. the airflow channel containing the oil mist to be detected) is provided with an optical window, so as to ensure that each optical element is physically isolated from the oil mist particles and prevent the oil stain from directly adhering. Specifically, the optical window of the infrared emitter 21 cavity functions to ensure that the infrared light beam emitted by the infrared emitter 21 can pass through the optical window unhindered and project onto the oil mist particles; the optical window of the first photodiode cavity functions to ensure that the scattered light signal generated by the oil mist particles can pass through the optical window, enter the cavity and be effectively received by the first photodiode; the optical window of the second photodiode cavity functions to ensure that the infrared light beam emitted by the infrared emitter 21 can pass through the optical window, enter the cavity and be effectively received by the second photodiode 23, so as to detect the light source intensity.

[0029] In the preferred embodiment of the present application, the optical window is made of an oil stain-proof window sheet made of quartz material and covered with a coating with oil mist adhesion prevention property.

[0030] Further, the main control circuit board 3 is also connected with an external power supply to supply power to the entire oil mist detector.

[0031] Further, the oil mist detector further comprises a fan 4 arranged at the air outlet 12 and connected with the main control circuit board 3, and the fan 4 is controlled to be opened and closed by the main control circuit board 3. It can be understood that the fan 4 is used to suck the oil mist particles from the air inlet 11 into the shell 1, and accelerate the oil mist particles to flow linearly from the air inlet 11 to the air outlet 12 (the direction of the arrow in the figure). This ensures that the airflow near the air outlet 12 reaches a high flow rate. According to the principle of fluid mechanics, such a fast linear flow channel helps to force the oil mist particles to pass through the linear airflow channel quickly, and reduces the opportunity of the oil mist particles to deposit and adhere to the shell wall surface and the optical window surface.

[0032] Further, the surface of the shell 1 is also provided with a three-color indicator light (not shown in the figure), which is connected with and driven by the main control circuit board 3, wherein the first indicator light color is used to indicate the normal working state (for example, green), the second indicator light color is used to indicate the abnormality when the light source intensity is less than the second threshold value (for example, yellow), and the third indicator light color is used to indicate the oil mist concentration exceeding the standard alarm (for example, red).

[0033] Further, the second indicator light is also used to indicate system failure, and the system failure includes that the infrared emitter 21 is damaged and cannot emit infrared light source, or the main control circuit board 3 cannot receive the scattered light signal from the first photodiode 22.

[0034] Further, the surface of the shell 1 is also provided with an audible and visual alarm (not shown in the figure), which is connected with and driven by the main control circuit board 3, and it needs to be noted that when the red indicator light is on, the audible and visual alarm will be triggered synchronously to alarm.

[0035] Further, the oil mist detector also comprises an externally connected oil mist detection panel (not shown in the figure), which is connected with the main control circuit board 3 and is used to receive the oil mist data transmitted by the main control circuit board 3 or to instruct control the main control circuit board 3; wherein the panel has a man-machine interface, allowing the user to input control instructions, view real-time graphical oil mist concentration data, query historical concentration records, and contains data storage function for subsequent analysis and management.

[0036] The second aspect of the present application provides an oil mist detection method, which is realized by using the oil mist detector, and specifically comprises the following steps: S1, when the oil mist detector is started, the main control circuit board 3 drives the fan 4 to start working, and the air containing oil mist particles is sucked into the shell 1 from the air inlet 11, and the oil mist particles flow straight from the air inlet 11 to the air outlet 12; S2, the main control circuit board 3 drives the infrared emitter 21 to emit an infrared light beam; S3, the second photodiode 23 receives the infrared light beam and converts it into a second electric signal reflecting the light source intensity and transmits it to the main control circuit board 3, and the main control circuit board 3 uses the second electric signal transmitted by the second photodiode 23 to determine whether the second electric signal is greater than or equal to the second threshold value, and triggers the infrared emitter 21 to work abnormally when the second electric signal is less than the second threshold value; S4, the first photodiode 22 receives the scattered light signal and converts it into a first electric signal and transmits it to the main control circuit board 3, and the main control circuit board 3 uses the first electric signal transmitted by the first photodiode 22 to calculate the real-time oil mist concentration; S5, if the main control circuit board 3 detects that the infrared emitter 21 is abnormal (such as the light source intensity is too low), the yellow fault indicator light is turned on, and the user is reminded to take corresponding measures to maintain the infrared emitter 21; if the main control circuit board 3 detects that the infrared emitter 21 is normal, and the oil mist concentration is less than the first threshold value, the green indicator light is turned on; if the main control circuit board 3 detects that the infrared emitter 21 is normal, but the oil mist concentration is greater than or equal to the first threshold value, the red indicator light is turned on, and the alarm is triggered to issue an alarm, reminding the user to take corresponding measures to reduce the oil mist concentration.

[0037] In summary, the oil mist detector and the detection method provided by the application are based on the light scattering principle, the oil mist concentration is inversely calculated by detecting the scattering intensity of the light beam of the oil mist particles, and the measurement accuracy is extremely high; the light source intensity emitted by the infrared emitter is detected by the designed first photodiode, the problems of the infrared emitter failure or aging are effectively solved, and the application has great practical value. At the same time, the application significantly reduces the equipment maintenance frequency and cost, provides an intelligent solution for equipment health management and environmental safety monitoring, and is especially suitable for scenes such as ships, power and petrochemicals which have strict requirements on oil mist concentration monitoring.

[0038] Although the content of the application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the application. After reading the above content, various modifications and alternatives of the application will be obvious to those skilled in the art. Therefore, the protection scope of the application should be defined by the appended claims.

Claims

1. An oil mist detector, characterized in that The oil mist detector comprises a shell, a plurality of detection assemblies, a main control circuit board, a fan, a three-color indicator lamp and an audible and visual alarm. The shell has an internal cavity structure, forms a containing space, and has an air inlet on the front surface and an air outlet on the back surface. The air inlet and the air outlet are coaxially arranged to form a straight airflow channel. The plurality of detection assemblies are arranged in the shell and comprise an infrared emitter, a first photodiode and a second photodiode. The infrared emitter is arranged on one side of the straight airflow channel in the shell and used for emitting an infrared light beam to oil mist particles flowing through the straight airflow channel. The first photodiode is arranged perpendicular to the direction of the infrared light beam and close to one end of the air outlet and used for receiving a scattered light signal generated by the oil mist particles under the irradiation of the infrared light beam. The second photodiode is arranged on the other side of the straight airflow channel in the shell and coaxially opposite to the infrared emitter and used for receiving the light source intensity of the infrared emitter. The main control circuit board is arranged in the shell and isolated from the area where the plurality of detection assemblies are arranged by a physical partition structure so that the oil mist particles cannot contact the main control circuit board. The main control circuit board is connected to each of the detection assemblies by wires and configured to: convert the scattered light signal received by the first photodiode into a first electric signal and calculate oil mist concentration data; determine whether the oil mist concentration is greater than or equal to a first threshold value and trigger an oil mist alarm when the oil mist concentration is greater than or equal to the first threshold value; convert the light source intensity signal received by the second photodiode into a second electric signal and determine the light source intensity; 2. The oil mist detector of claim 1, wherein determine whether the second electric signal is greater than or equal to a second threshold value and trigger an infrared emitter abnormality alarm when the second electric signal is less than the second threshold value.

3. The oil mist detector of claim 1, wherein The air inlet and the air outlet are both louver structures.

4. The oil mist detector of claim 1, wherein The wavelength of the infrared light emitted by the infrared emitter matches the diameter of the oil mist particles, which is 1-10 μm.

5. The oil mist detector of claim 4, wherein The infrared emitter, the first photodiode and the second photodiode are all sealed in independent cavities, each cavity is fixed to the inner wall of the shell, and one side of each cavity facing the straight airflow channel is provided with an optical window.

6. The oil mist detector of claim 1, wherein The optical window is an oil-proof window sheet made of quartz and covered with a coating having an oil mist adhesion prevention property. The oil mist detector further comprises a fan arranged at the air outlet end, connected to the main control circuit board and controlled to be turned on or off by the main control circuit board.

7. The oil mist detector of claim 1, wherein The fan is used to suck the oil mist particles from the air inlet into the shell and make the oil mist particles accelerate and flow straight along the air inlet to the air outlet. The three-color indicator lamp is arranged on the surface of the shell and connected to the main control circuit board.

8. The oil mist detector of claim 1, wherein The first indicator lamp color is used to indicate a normal working state, the second indicator lamp color is used to indicate an abnormality when the light source intensity is less than the second threshold value, and the third indicator lamp color is used to indicate an alarm when the oil mist concentration exceeds the first threshold value. The audible and visual alarm is arranged on the surface of the shell and connected to the main control circuit board.

9. The oil mist detector of claim 1, wherein The audible and visual alarm is triggered to alarm when the main control circuit board determines that the oil mist concentration is greater than or equal to the first threshold value. The oil mist detection panel is arranged outside and connected to the main control circuit board and used to receive the oil mist data transmitted by the main control circuit board or to instruct and control the main control circuit board. The oil mist detection panel comprises a man-machine interface configured to allow a user to input control instructions, display graphical oil mist concentration data in real time, query historical concentration records, and provide data storage functions.

10. An oil mist detection method, implemented using the oil mist detector according to any one of claims 1-9, characterized by, The method comprises the following steps: S1, the oil mist detector is started, the main control circuit board drives the fan to work, air containing oil mist particles is sucked into the shell from the air inlet, and the oil mist particles flow straight from the air inlet to the air outlet; S2, the main control circuit board drives the infrared emitter to emit an infrared light beam; S3, the second photodiode receives the infrared light beam and converts it into a second electric signal reflecting the light source intensity and transmits it to the main control circuit board, the main control circuit board uses the second electric signal transmitted by the second photodiode to determine whether the second electric signal is greater than or equal to a second threshold value; wherein if the second electric signal is less than the second threshold value, the second indicator light is triggered to light up, and the infrared emitter is triggered to work abnormally to alarm; S4, the first photodiode receives the scattered light signal and converts it into a first electric signal and transmits it to the main control circuit board, the main control circuit board uses the first electric signal transmitted by the first photodiode to calculate the real-time oil mist concentration and determine whether the oil mist concentration is greater than or equal to a first threshold value; wherein if the oil mist concentration is greater than or equal to the first threshold value, the third indicator light is triggered to light up, and the alarm is triggered to alarm.

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