CN111928768B - Device and method for detecting icing of crankcase ventilation pipeline - Google Patents
Device and method for detecting icing of crankcase ventilation pipeline Download PDFInfo
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- CN111928768B CN111928768B CN202010758540.1A CN202010758540A CN111928768B CN 111928768 B CN111928768 B CN 111928768B CN 202010758540 A CN202010758540 A CN 202010758540A CN 111928768 B CN111928768 B CN 111928768B
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- G01B7/06—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
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Abstract
The invention discloses a device and a method for detecting icing of a crankcase ventilation pipeline, wherein the device comprises: the device comprises a detection capacitor, a power supply component, a current measuring component and a voltage measuring component. The detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected. The first capacitive electrode is electrically connected to a first terminal of the power supply assembly and the second capacitive electrode is electrically connected to a second terminal of the power supply assembly. The current measuring component is used for measuring the current flowing through the detection capacitor. The voltage measurement component is used for measuring the voltage between the first capacitance electrode and the second capacitance electrode. Can detect out the frozen thickness of crankcase ventilation pipeline, need not to judge indirectly through measuring crankcase ventilation system pressure, need not the dismouting pipeline and confirm frozen state, simplify the detection process, reduce the detection degree of difficulty, and then reduced the detection cost.
Description
Technical Field
The invention relates to the field of engine crankcase ventilation systems, in particular to a crankcase ventilation pipeline icing detection device and method.
Background
Crankcase ventilation systems are one of the important components of engines, and are mainly used for preventing the pressure in the crankcase from being too high and prolonging the service life of engine oil.
The crankcase ventilation system generally comprises an internal structure and an external structure, wherein the external structure mainly comprises various ventilation pipelines, mixed gas containing water vapor can flow in the pipelines in the running process of an engine, and the problem of icing of the crankcase ventilation pipelines occurs in winter in the north, so that the internal pressure of the crankcase is too high, and the sealing failure is caused; or crushed ice entering the supercharger turbine, causing supercharger damage.
In the existing measuring device, the pressure of a crankcase ventilation system is generally measured for indirect judgment, a pipeline needs to be assembled and disassembled to confirm the icing state, the process is complicated, and the operation is difficult.
Disclosure of Invention
The embodiment of the invention provides a device and a method for detecting icing of a crankcase ventilation pipeline, which can detect the icing thickness of the crankcase ventilation pipeline, do not need indirect judgment through measuring the pressure of a crankcase ventilation system, do not need to disassemble and assemble the pipeline to confirm the icing state, simplify the detection process, reduce the detection difficulty and further reduce the detection cost.
In a first aspect, an embodiment of the present invention provides a crankcase ventilation pipeline icing detection apparatus, including: the detection capacitor, the power supply component, the current measurement component and the voltage measurement component;
the detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected;
the first capacitive electrode is electrically connected with a first end of the power supply assembly, and the second capacitive electrode is electrically connected with a second end of the power supply assembly;
the current measuring component is used for measuring the current flowing through the detection capacitor;
the voltage measurement component is used for measuring the voltage between the first capacitance electrode and the second capacitance electrode.
Optionally, the crankcase ventilation line icing detection apparatus further comprises a support;
the support comprises a surrounding part, a first support part and a second support part, and is used for supporting the first capacitance electrode and the second capacitance electrode;
the surrounding part wraps the to-be-detected ventilation pipeline;
the first supporting part and the second supporting part are respectively connected to the surrounding part;
the first capacitor electrode is disposed on the first supporting portion, and the second capacitor electrode is disposed on the second supporting portion.
Optionally, the first capacitor electrode and the second capacitor electrode are arc-shaped electrode plates bending towards the ventilation pipeline to be detected, and arc centers of the electrode plates are located on an axis of the ventilation pipeline to be detected.
Optionally, the power supply assembly includes a dc power supply and an inverter;
a first end of the inverter is electrically connected with a first end of the direct current power supply, and a second end of the inverter is electrically connected with the first capacitor electrode;
the inverter is used for converting the direct current output by the direct current power supply into alternating current and outputting the alternating current to the detection capacitor.
Optionally, the voltage measuring component includes a first voltmeter, a first end of the first voltmeter is electrically connected to the first capacitor electrode, and a second end of the first voltmeter is electrically connected to the second capacitor electrode.
Optionally, the current measuring component comprises a measuring resistor and a second voltmeter;
the measuring resistor and the detecting capacitor are connected in series in a circuit, the first end of the second voltmeter is electrically connected with the first end of the measuring resistor, and the second end of the second voltmeter is electrically connected with the second end of the measuring resistor.
Optionally, the crankcase ventilation pipeline icing detection device further comprises a voltage amplification circuit, and the voltage amplification circuit is used for amplifying the voltage at two ends of the detection capacitor;
the input end of the voltage amplifying circuit is electrically connected with the second capacitor electrode, and the output end of the voltage amplifying circuit is electrically connected with the second end of the power supply assembly;
the first end of the voltage measuring component is electrically connected with the first capacitor electrode, and the second end of the voltage measuring component is electrically connected with the output end of the voltage amplifying circuit.
Optionally, the voltage amplifying circuit includes a first amplifying resistor, a second amplifying resistor, and an operational amplifier;
the first end of the first amplifying resistor is electrically connected with the second capacitor electrode, and the second end of the first amplifying resistor is electrically connected with the inverting input end of the operational amplifier;
a first end of the second amplifying resistor is electrically connected with an inverting input end of the operational amplifier, and a second end of the second amplifying resistor is electrically connected with an output end of the operational amplifier;
the output end of the operational amplifier is electrically connected with the second end of the power supply assembly, and the positive phase input end of the operational amplifier is grounded.
Optionally, the crankcase ventilation pipeline icing detection device further comprises a first oscilloscope and a second oscilloscope;
the first end of the first oscilloscope is electrically connected with the first capacitor electrode, and the second end of the first oscilloscope is electrically connected with the second capacitor electrode;
and the first end of the second oscilloscope is electrically connected with the first end of the measuring resistor, and the second end of the second oscilloscope is electrically connected with the second end of the measuring resistor.
In a second aspect, an embodiment of the present invention provides a method for detecting icing on a crankcase ventilation pipeline, where the method is based on the apparatus provided in the first aspect of the present invention, and includes:
respectively acquiring current flowing through the detection capacitor and voltage at two ends of the detection capacitor through the current measurement component and the voltage measurement component;
calculating a capacitive reactance of the detection capacitance based on the current and voltage;
calculating a capacitance value of the detection capacitor according to the following formula:
wherein C is the capacitance value of the detection capacitor, f is the voltage frequency of the power supply assembly, and Xc is the capacitive reactance of the detection capacitor;
and calculating the thickness of the ice layer in the ventilation pipeline according to the relation between the capacitance value and the thickness of the dielectric medium.
The crankcase ventilation pipeline icing detection device provided by the embodiment of the invention comprises: the device comprises a detection capacitor, a power supply component, a current measuring component and a voltage measuring component. The detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected. The first capacitive electrode is electrically connected to a first terminal of the power supply assembly and the second capacitive electrode is electrically connected to a second terminal of the power supply assembly. The current measuring component is used for measuring the current flowing through the detection capacitor. The voltage measurement component is used for measuring the voltage between the first capacitance electrode and the second capacitance electrode. The current flowing through the detection capacitor is measured by the current measuring component, the voltage between two electrodes (namely the first capacitor electrode and the second capacitor electrode) of the detection capacitor is measured by the voltage measuring component, the capacitive reactance of the detection capacitor is calculated by the current flowing through the detection capacitor and the voltage between the two electrodes of the detection capacitor, the current capacitance value of the detection capacitor is calculated according to the relation between the capacitive reactance and the capacitance value, and the thickness of the ice layer in the ventilation pipeline is calculated according to the relation between the capacitance value and the thickness of the dielectric medium. Can detect out the frozen thickness of crankcase ventilation pipeline, need not to judge indirectly through measuring crankcase ventilation system pressure, need not the dismouting pipeline and confirm frozen state, simplify the detection process, reduce the detection degree of difficulty, and then reduced the detection cost.
Drawings
The invention is explained in more detail below with reference to the figures and examples.
Fig. 1 is a block diagram of a circuit structure of an icing detection device for a crankcase ventilation pipeline according to an embodiment of the invention;
fig. 2 is a schematic structural diagram of an icing detection apparatus for a crankcase ventilation pipeline according to an embodiment of the present invention;
FIG. 3 is a cross-sectional view of the sensing device of FIG. 2 taken along section line A-A;
fig. 4 is a schematic diagram of a voltage amplifying circuit according to an embodiment of the invention;
fig. 5 is a flowchart of a method for detecting icing on a crankcase ventilation pipeline according to a second embodiment of the present invention.
Detailed Description
In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature. Furthermore, the terms "first" and "second" are used merely for descriptive purposes and are not intended to have any special meaning.
Example one
The embodiment of the invention provides a crankcase ventilation pipeline icing detection device which can be used for detecting icing conditions in a crankcase ventilation pipeline. Fig. 1 is a block diagram of a circuit structure of an icing detection apparatus for a crankcase ventilation pipeline according to an embodiment of the present invention, as shown in fig. 1, the apparatus includes: a sensing capacitor 10, a power supply component 20, a current measuring component 30 and a voltage measuring component 40.
The detection capacitor 10 comprises a first capacitor electrode 11 and a second capacitor electrode 12, and the first capacitor electrode 11 and the second capacitor electrode 12 are oppositely arranged on two sides of the ventilation pipeline to be detected. In the embodiment of the present invention, the first capacitor electrode 11 and the second capacitor electrode 12 may be attached to the outer wall of the ventilation pipeline to be detected, or may be spaced from the outer wall of the ventilation pipeline to be detected, which is not limited herein. The first capacitance electrode 11 and the second capacitance electrode 12 may be straight electrode plates, or may also be arc-shaped electrode plates that are adapted to the shape of the outer wall of the ventilation pipeline to be detected, which is not limited herein in the embodiment of the present invention.
The first capacitive electrode 11 is electrically connected to a first terminal of the power module 20, and the second capacitive electrode 12 is electrically connected to a second terminal of the power module 20. Wherein the power supply assembly 20 is adapted to generate a steady alternating current. The specific form of the power supply assembly 20 may be a direct ac power supply, or a combination of a dc power supply and an inverter, and the embodiment of the present invention is not limited herein.
The current measuring assembly 30 is used to measure the current flowing through the sensing capacitor 10. It should be noted that, in the embodiment of the present invention, the current flowing through the detection capacitor 10 is an alternating current, and the current measured by the current measuring component 30 may be an effective value of the alternating current. Illustratively, taking the AC current as a sinusoidal AC current, the maximum value of the sinusoidal AC current is ImThe effective value measured by the current measuring assembly 30 is
The current measuring component 30 in the embodiment of the present invention may be an ammeter for directly measuring current, or may be a device for indirectly measuring current, such as a voltmeter and a resistor, and the embodiment of the present invention is not limited herein.
The voltage measurement component 40 is used to measure the voltage between the first capacitive electrode 11 and the second capacitive electrode 12. In the embodiment of the present invention, the voltage between the first capacitive electrode 11 and the second capacitive electrode 12 is an ac voltage, and the voltage measured by the voltage measuring component 40 may be an effective value of the ac voltage. Illustratively, taking the ac voltage as a sinusoidal ac voltage, the maximum value of the sinusoidal ac voltage is VmThen the effective value measured by the voltage measuring component 40 is
The voltage measuring component 40 in the embodiment of the present invention may be a voltmeter directly used for measuring voltage, or may be a device used for indirectly measuring voltage, such as a current meter and a resistor, which is not limited herein.
Specifically, the detection principle of the crankcase ventilation pipeline icing detection device in the embodiment of the invention is as follows:
the power supply assembly 20 powers on the detection capacitor, the current measurement assembly 30 and the voltage measurement assembly 40, the current flowing through the detection capacitor 10 is measured by the current measurement assembly 30, the voltage between two electrodes (namely the first capacitor electrode 11 and the second capacitor electrode 12) of the detection capacitor 10 is measured by the voltage measurement assembly 40, the capacitive reactance of the detection capacitor 10 is calculated by the current flowing through the detection capacitor 10 and the voltage between the two electrodes of the detection capacitor 10, the current capacitance value of the detection capacitor 10 is calculated according to the relation between the capacitive reactance and the capacitance value, and the thickness of an ice layer in the ventilation pipeline is calculated according to the relation between the capacitance value and the thickness of a dielectric medium. In a specific embodiment, a corresponding relationship between the voltage between the two electrodes of the detection capacitor 10 and the thickness of the ice layer may be established, and after the voltage between the two electrodes of the detection capacitor 10 is measured, the corresponding thickness of the ice layer may be found directly according to the corresponding relationship.
The crankcase ventilation pipeline icing detection device provided by the embodiment of the invention comprises: the device comprises a detection capacitor, a power supply component, a current measuring component and a voltage measuring component. The detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected. The first capacitive electrode is electrically connected to a first terminal of the power supply assembly and the second capacitive electrode is electrically connected to a second terminal of the power supply assembly. The current measuring component is used for measuring the current flowing through the detection capacitor. The voltage measurement component is used for measuring the voltage between the first capacitance electrode and the second capacitance electrode. The current flowing through the detection capacitor is measured by the current measuring component, the voltage between two electrodes (namely the first capacitor electrode and the second capacitor electrode) of the detection capacitor is measured by the voltage measuring component, the capacitive reactance of the detection capacitor is calculated by the current flowing through the detection capacitor and the voltage between the two electrodes of the detection capacitor, the current capacitance value of the detection capacitor is calculated according to the relation between the capacitive reactance and the capacitance value, and the thickness of the ice layer in the ventilation pipeline is calculated according to the relation between the capacitance value and the thickness of the dielectric medium. Can detect out the frozen thickness of crankcase ventilation pipeline, need not to judge indirectly through measuring crankcase ventilation system pressure, need not the dismouting pipeline and confirm frozen state, simplify the detection process, reduce the detection degree of difficulty, and then reduced the detection cost.
Fig. 2 is a schematic structural view of a crankcase ventilation pipeline icing detection device according to an embodiment of the invention, fig. 3 is a cross-sectional view of the detection device in fig. 2 along a sectional line a-a, and in some embodiments of the invention, as shown in fig. 2 and 3, the device may further include a support 50. The support 50 includes a surrounding portion 51, a first support portion 52, and a second support portion 53, and the support 50 is used to support the first capacitive electrode 11 and the second capacitive electrode 12.
Specifically, the surrounding portion 51 wraps the ventilation pipe 70 to be tested. The surrounding portion 51 may be a sleeve made of plastic material, and is sleeved on the to-be-detected ventilation pipeline 70. In the embodiment of the present invention, in order to reduce the heat insulation effect of the surrounding portion 51 on the ventilation pipeline 70 to be detected, the thickness of the surrounding portion 51 is as thin as possible.
The first support portion 52 and the second support portion 53 are respectively coupled to the surrounding portion 51 and protrude from the surrounding portion 51. The first capacitor electrode 11 is disposed on the first support portion 52, and the second capacitor electrode 12 is disposed on the second support portion 53.
Specifically, in some embodiments of the present invention, the first supporting portion 52 may include a first supporting body protruding from the surrounding portion 51 and a first electrode pad on the first supporting body, on which the first capacitor electrode 11 is disposed. The first supporting portion 52 enables a gap to be formed between the first capacitor electrode 11 and the ventilation pipeline 70 to be detected, so that the first capacitor electrode 11 is prevented from being attached to the outer wall of the ventilation pipeline 70 to be detected, and the heat preservation effect of the ventilation pipeline 70 to be detected is avoided. Similarly, the second supporting portion 53 may include a first supporting body protruding from the surrounding portion 51 and a second electrode pad on the first supporting body, and the second capacitive electrode 12 is disposed on the second electrode pad. The second supporting portion 53 enables a gap to be formed between the second capacitive electrode 12 and the ventilation pipeline 70 to be detected, so that the second capacitive electrode 12 is prevented from being attached to the outer wall of the ventilation pipeline 70 to be detected, and the heat preservation effect of the ventilation pipeline 70 to be detected is avoided.
In the above embodiment, the surrounding portion 51, the first support portion 52, and the second support portion 53 are integrally molded, for example, by injection molding of epoxy resin. And after the test is finished, the supporting piece 50 and the ventilation pipeline 70 to be detected can be detached at any time, so that the influence of the heat insulation performance of the crankcase ventilation pipeline of the supporting piece 50 is reduced.
In some embodiments of the present invention, as shown in fig. 2, the first capacitive electrode 11 and the second capacitive electrode 12 are arc-shaped electrode plates that are bent toward the ventilation pipeline 70 to be detected, and arc centers of the electrode plates are located on an axis of the ventilation pipeline 70 to be detected, so as to ensure that the first capacitive electrode 11 and the second capacitive electrode 12 are respectively parallel to a pipe wall of the ventilation pipeline 70 to be detected, thereby ensuring accuracy of the calculated capacitance value.
In some embodiments of the present invention, the power supply assembly 20 includes a dc power supply 21 and an inverter 22.
Specifically, a first terminal of the inverter 22 is electrically connected to a first terminal of the dc power supply 21, and a second terminal of the inverter 22 is electrically connected to the first capacitor electrode 11.
Illustratively, the dc power source 21 may be a battery pack including a plurality of secondary batteries.
The inverter 22 is a converter for converting the dc power output from the dc power supply 21 into constant-frequency constant-voltage or frequency-modulated voltage-regulated ac power (e.g., 220V, 50Hz sine wave). It is composed of inverter bridge, control logic and filter circuit. Specifically, the operation principle of the inverter 22 is a general principle in the art, and the embodiment of the present invention is not described herein again.
Illustratively, as shown in fig. 2, in the embodiment of the present invention, the voltage measuring component 40 may be a voltmeter, which is referred to as a first voltmeter V1. A first terminal of a first voltmeter V1 is electrically connected with first capacitor electrode 11, and a second terminal of a first voltmeter V1 is electrically connected with second capacitor electrode 12. The first voltmeter V1 is an ac voltmeter for measuring the effective voltage across the detection capacitor 10.
Illustratively, current measuring assembly 30 includes a measuring resistor R1 and a second voltmeter V2.
Specifically, the measuring resistor R1 and the detection capacitor 10 are connected in series in the circuit, the first end of the second voltmeter V2 is electrically connected with the first end of the measuring resistor R1, and the second end of the second voltmeter V2 is electrically connected with the second end of the measuring resistor R1. The second voltmeter V2 is an ac voltmeter for measuring the effective voltage across the measuring resistor R1. By measuring the effective voltage of the resistor R1 and measuring the resistance of the resistor R1, the effective current in the circuit, i.e. the effective current flowing through the sensing capacitor 10, can be calculated.
Since the capacitance value sensed by the detection capacitor 10 and the capacitance value variation are small, the voltage variation measured by the voltage measurement component 40 is also small, which is inconvenient to observe. Therefore, the voltage signal across the detection capacitor 10 can be amplified by a common amplifier circuit, so as to observe the variation. Specifically, in some embodiments of the present invention, as shown in fig. 2, the detection apparatus may further include a voltage amplifying circuit 60, and the voltage amplifying circuit 60 is configured to amplify the voltage across the detection capacitor 10.
Specifically, the input terminal of the voltage amplifying circuit 60 is electrically connected to the second capacitor electrode 12, the output terminal of the voltage amplifying circuit 60 is electrically connected to the second terminal of the power supply module 20, and in this embodiment, the output terminal of the voltage amplifying circuit 60 is electrically connected to the first terminal of the measuring resistor R1.
A first terminal of the voltage measuring unit 40 is electrically connected to the first capacitor electrode 11, and a second terminal of the voltage measuring unit 40 is electrically connected to an output terminal of the voltage amplifying circuit 60. In this embodiment, a first terminal of the first voltmeter V1 is electrically connected to the first capacitor electrode 11, and a second terminal of the first voltmeter V1 is electrically connected to the output terminal of the voltage amplifying circuit 60.
Fig. 4 is a schematic diagram of a voltage amplifying circuit according to a first embodiment of the present invention, and exemplarily, as shown in fig. 4, the voltage amplifying circuit 60 includes a first amplifying resistor R2, a second amplifying resistor R3, and an operational amplifier UA.
Specifically, a first end of the first amplifying resistor R2 is electrically connected to the second capacitor electrode 12, and a second end of the first amplifying resistor R2 is electrically connected to the inverting input terminal of the operational amplifier UA. A first end of the second amplifying resistor R3 is electrically connected to the inverting input terminal of the operational amplifier UA, and a second end of the second amplifying resistor R3 is electrically connected to the output terminal of the operational amplifier UA. The output terminal of the operational amplifier UA is electrically connected to the second terminal of the power supply module 20 (in this embodiment, the output terminal of the operational amplifier UA is electrically connected to the first terminal of the measuring resistor R1), and the non-inverting input terminal of the operational amplifier UA is grounded through the grounding resistor R4.
In the above embodiments, the circuit structure of the voltage amplifying circuit is an exemplary illustration of the embodiments of the present invention, and is not a specific limitation of the present invention. In other embodiments of the present invention, the voltage amplifying circuit may have other circuit structures.
In some embodiments of the present invention, as shown in FIG. 2, the crankcase ventilation line icing detection apparatus may further comprise a first oscilloscope T1 and a second oscilloscope T2.
A first terminal of a first oscilloscope T1 is electrically connected to first capacitor electrode 11, and a second terminal of first oscilloscope T1 is electrically connected to second capacitor electrode 12. The first oscilloscope T1 is used to display the waveform of the voltage of the detection capacitor 10.
The first end of the second oscilloscope T2 is electrically connected to the first end of the measuring resistor R1, and the second end of the second oscilloscope T is electrically connected to the second end of the measuring resistor R1. The second oscilloscope T2 is used to display the waveform of the voltage of the measuring resistor R1.
Due to the hysteresis of the detection capacitor 10, the voltage across the measuring resistor R1 is 90 ° out of phase with the voltage across the measuring resistor R1. The first oscilloscope T1 and the second oscilloscope T2 respectively display the waveform of the voltage of the detection capacitor 10 and the waveform of the voltage of the measurement resistor R1, the phase difference of 90 degrees between the voltage of the measurement resistor R1 and the voltage of the measurement resistor R1 is verified, the phase change caused by faults does not exist in the circuit, and the accuracy of the detection result is guaranteed.
Example two
An embodiment of the invention provides a crankcase ventilation pipeline icing detection method, which is based on the crankcase ventilation pipeline icing detection device provided by the embodiment of the invention, and the device comprises: the device comprises a detection capacitor, a power supply component, a current measuring component and a voltage measuring component.
The power supply assembly is used for generating stable alternating current.
The detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected.
The first capacitive electrode is electrically connected to a first terminal of the power supply assembly and the second capacitive electrode is electrically connected to a second terminal of the power supply assembly.
The current measuring component is used for measuring the current flowing through the detection capacitor, and it should be noted that, in the embodiment of the present invention, the current flowing through the detection capacitor is an alternating current, and the current measured by the current measuring component may be an effective value of the alternating current.
The voltage measuring component is used for measuring a voltage between the first capacitive electrode and the second capacitive electrode, it should be noted that, in the embodiment of the present invention, the voltage between the first capacitive electrode and the second capacitive electrode is an alternating voltage, and what the voltage measuring component measures may be an effective value of the alternating voltage.
Fig. 5 is a flowchart of a method for detecting icing on a crankcase ventilation pipeline according to a second embodiment of the present invention, and specifically, as shown in fig. 5, the method includes the following steps:
s101, respectively acquiring current flowing through the detection capacitor and voltage at two ends of the detection capacitor through the current measurement component and the voltage measurement component.
Specifically, the power supply module powers on the detection capacitor, the current measurement module and the voltage measurement module, the current flowing through the detection capacitor is measured by the current measurement module, and the voltage between two electrodes (i.e., the first capacitor electrode and the second capacitor electrode) of the detection capacitor is measured by the voltage measurement module.
Specifically, in this embodiment, the voltage measuring component is a first voltmeter directly measuring the effective voltage U at the two ends of the detection capacitor1. The current measuring component comprises a measuring resistor and a second voltmeter, the measuring resistor and the detecting capacitor are connected in series in the circuit, and the second voltmeter is used for measuring effective voltage at two ends of the measuring resistor. By measuring the effective voltage of the resistor and measuring the resistance of the resistor, the effective current in the circuit, i.e. the effective current I flowing through the detection capacitor, can be calculated1。
And S102, calculating the capacitive reactance of the detection capacitor based on the current and the voltage.
Specifically, let the capacitive reactance of the detection capacitor be XcThen capacitive reactance Xc＝U1/I1。
And S103, calculating the capacitance value of the detection capacitor according to the relation between the capacitive reactance and the capacitance value.
In particular, capacitive reactance XcCan be calculated by the following formula:
where C is the capacitance of the detection capacitor, f is the voltage frequency of the power supply assembly, XcTo detect the capacitive reactance of the capacitor.
Then, the capacitance value C of the detection capacitor can be calculated by the following formula:
and S104, calculating the thickness of the ice layer in the ventilation pipeline according to the thickness relation between the capacitance value and the dielectric medium.
Specifically, according to the characteristics of the medium-variable capacitor, the capacitance of the capacitor is related to the properties of the medium, and when no ice is generated in the crankcase ventilation pipeline, the total capacitance Ca between the two electrodes of the detection capacitor is determined by the plastic capacitance C1, the air capacitance C3 and the rubber capacitance C4, which are equivalent to the three capacitors connected in series, so that the capacitance Ca of the detection capacitor when no ice is generated in the crankcase ventilation pipeline is obtained by the relationship among the capacitance Ca of the detection capacitor, the capacitance C1, the capacitance C3 and the capacitance C4:
from the above, the capacitance Ca of the detection capacitor when ice is present in the crankcase ventilation duct can be determined.
When ice is generated in the crankcase ventilation pipeline, the total capacitance Cb between the two electrodes of the detection capacitor is determined by the plastic capacitance C1, the ice capacitance C2, the air capacitance C3 and the rubber capacitance C4, which is equivalent to that four capacitors are connected in series, so that the relation between the capacitance Cb of the detection capacitor when ice is generated in the crankcase ventilation pipeline and the capacitance C1, C3 and C4 is as follows:
from the above, the capacitance Cb of the detection capacitor when ice is present in the crankcase ventilation line, that is, the capacitance C of the detection capacitor obtained in step S103 can be obtained.
Since the plastic capacitance C1 and the rubber capacitance C4 are fixed, the ice capacitance C2 and the air capacitance C3 can be determined.
Hypothesis detectionThe medium between two electrodes of the capacitor is plastic (i.e. the material of the support), ice and air respectively, and the dielectric constant of the plastic is epsilon1The dielectric constant of ice is epsilon2Dielectric constant of air is epsilon3Dielectric constant of rubber (material of the vent pipe to be detected) is epsilon4。
According to the capacitance value and dielectric constant, the dielectric thickness and the area formula:
wherein C is a capacitance value, epsilon is a dielectric constant of the medium, S is an area of the medium, namely an area of an electrode of the detection capacitor, and h is a thickness of ice in the ventilation pipeline to be detected.
The thickness h of the ice in the ventilation pipeline to be detected can be calculated according to the formula.
According to the method for detecting the icing of the ventilation pipeline of the crankcase, provided by the embodiment of the invention, the current flowing through the detection capacitor and the voltage at two ends of the detection capacitor are respectively obtained through the current measuring component and the voltage measuring component, the capacitive reactance of the detection capacitor is calculated based on the current and the voltage, the capacitance value of the detection capacitor is calculated according to the relation between the capacitive reactance and the capacitance value, and the thickness of an ice layer in the ventilation pipeline is calculated according to the relation between the capacitance value and the thickness of a dielectric medium. Can detect out the frozen thickness of crankcase ventilation pipeline, need not to judge indirectly through measuring crankcase ventilation system pressure, need not the dismouting pipeline and confirm frozen state, simplify the detection process, reduce the detection degree of difficulty, and then reduced the detection cost.
In the description herein, it is to be understood that the terms "upper", "lower", "left", "right", and the like are used in a descriptive sense or positional relationship based on the orientation or positional relationship shown in the drawings for convenience in description and simplicity of operation, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present invention.
In the description herein, references to the description of "an embodiment," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be appropriately combined to form other embodiments as will be appreciated by those skilled in the art.
The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.
Claims (7)
1. The utility model provides a crankcase ventilation pipeline detection device that freezes which characterized in that includes: the detection capacitor, the power supply component, the current measurement component and the voltage measurement component;
the detection capacitor comprises a first capacitor electrode and a second capacitor electrode, and the first capacitor electrode and the second capacitor electrode are oppositely arranged on two sides of the ventilation pipeline to be detected;
the first capacitive electrode is electrically connected with a first end of the power supply assembly, and the second capacitive electrode is electrically connected with a second end of the power supply assembly;
the current measuring component is used for measuring the current flowing through the detection capacitor;
the voltage measuring component is used for measuring the voltage between the first capacitance electrode and the second capacitance electrode;
the crankcase ventilation pipeline icing detection device further comprises a support piece;
the support comprises a surrounding part, a first support part and a second support part, and is used for supporting the first capacitance electrode and the second capacitance electrode;
the surrounding part wraps the to-be-detected ventilation pipeline;
the first supporting part and the second supporting part are respectively connected to the surrounding part;
the first capacitor electrode is arranged on the first supporting part, and the second capacitor electrode is arranged on the second supporting part;
the current measuring component comprises a measuring resistor and a second voltmeter;
the measuring resistor and the detecting capacitor are connected in series in a circuit, a first end of the second voltmeter is electrically connected with a first end of the measuring resistor, and a second end of the second voltmeter is electrically connected with a second end of the measuring resistor;
the crankcase ventilation pipeline icing detection device further comprises a first oscilloscope and a second oscilloscope;
the first end of the first oscilloscope is electrically connected with the first capacitor electrode, and the second end of the first oscilloscope is electrically connected with the second capacitor electrode;
and the first end of the second oscilloscope is electrically connected with the first end of the measuring resistor, and the second end of the second oscilloscope is electrically connected with the second end of the measuring resistor.
2. The crankcase ventilation pipeline icing detection device according to claim 1, wherein the first capacitive electrode and the second capacitive electrode are arc-shaped electrode plates which are bent towards the ventilation pipeline to be detected, and arc centers of the electrode plates are located on an axis of the ventilation pipeline to be detected.
3. The crankcase ventilation circuit icing detection apparatus according to any one of claims 1-2, wherein the power supply assembly includes a dc power supply and an inverter;
a first end of the inverter is electrically connected with a first end of the direct current power supply, and a second end of the inverter is electrically connected with the first capacitor electrode;
the inverter is used for converting the direct current output by the direct current power supply into alternating current and outputting the alternating current to the detection capacitor.
4. The crankcase ventilation circuit icing detection apparatus of any one of claims 1-2, wherein the voltage measurement assembly comprises a first voltmeter having a first end electrically connected to the first capacitive electrode and a second end electrically connected to the second capacitive electrode.
5. The crankcase ventilation circuit icing detection device according to any one of claims 1-2, further comprising a voltage amplification circuit for amplifying a voltage across the detection capacitor;
the input end of the voltage amplifying circuit is electrically connected with the second capacitor electrode, and the output end of the voltage amplifying circuit is electrically connected with the second end of the power supply assembly;
the first end of the voltage measuring component is electrically connected with the first capacitor electrode, and the second end of the voltage measuring component is electrically connected with the output end of the voltage amplifying circuit.
6. The crankcase ventilation line icing detection apparatus of claim 5, wherein the voltage amplification circuit comprises a first amplification resistor, a second amplification resistor, and an operational amplifier;
the first end of the first amplifying resistor is electrically connected with the second capacitor electrode, and the second end of the first amplifying resistor is electrically connected with the inverting input end of the operational amplifier;
a first end of the second amplifying resistor is electrically connected with an inverting input end of the operational amplifier, and a second end of the second amplifying resistor is electrically connected with an output end of the operational amplifier;
the output end of the operational amplifier is electrically connected with the second end of the power supply assembly, and the positive phase input end of the operational amplifier is grounded.
7. A crankcase ventilation line icing detection method, characterized in that the device according to any one of claims 1-6 comprises:
respectively acquiring current flowing through the detection capacitor and voltage at two ends of the detection capacitor through the current measurement component and the voltage measurement component;
calculating a capacitive reactance of the detection capacitance based on the current and voltage;
calculating a capacitance value of the detection capacitor according to the following formula:
wherein C is the capacitance value of the detection capacitor, f is the voltage frequency of the power supply assembly, and Xc is the capacitive reactance of the detection capacitor;
and calculating the thickness of the ice layer in the ventilation pipeline according to the relation between the capacitance value and the thickness of the dielectric medium.
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| CN202010758540.1A CN111928768B (en) | 2020-07-31 | 2020-07-31 | Device and method for detecting icing of crankcase ventilation pipeline |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1737490A (en) * | 2005-09-01 | 2006-02-22 | 太原理工大学 | Condenser type ice layer thickness sensor and detecting method thereof |
| CN101285673A (en) * | 2008-06-06 | 2008-10-15 | 太原理工大学 | Capacitance ratio type ice-covering thickness sensor and its detection method |
| CN103016099A (en) * | 2012-12-25 | 2013-04-03 | 中国第一汽车股份有限公司 | Ventilating and heating system of crankcase |
| CN103292683A (en) * | 2013-05-31 | 2013-09-11 | 太原理工大学 | Capacitive sensing type detection device and detection method for ice cover thickness of overhead power transmission lines |
| CN104197205A (en) * | 2014-09-17 | 2014-12-10 | 太原理工大学 | Pipe network blocking detecting device |
| CN204989497U (en) * | 2015-09-22 | 2016-01-20 | 江西飞尚科技有限公司 | Contact ice sheet detects sensor |
| CN106500582A (en) * | 2016-11-23 | 2017-03-15 | 合肥市芯海电子科技有限公司 | A kind of solidifying frost detection means of refrigerator condenser type and detection method |
| CN109764913A (en) * | 2019-02-22 | 2019-05-17 | 昆明大蚯蚓科技有限公司 | Pavement conditions detection device and method |
| CN109974571A (en) * | 2018-12-24 | 2019-07-05 | 天津天商酷凌科技有限公司 | A kind of condenser type multiple-effect frost sensor that evaporator has |
| CN209764004U (en) * | 2019-05-24 | 2019-12-10 | 西安工程大学 | Icing thickness measuring device based on variable-medium capacitive sensor |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2636234Y (en) * | 2003-07-11 | 2004-08-25 | 清华同方股份有限公司 | RC type ice-containing rate sensor |
| CN101221036A (en) * | 2008-01-25 | 2008-07-16 | 太原理工大学 | Capacitance chromatography imaging type ice thickness detecting device and its detecting method |
| CN102183791A (en) * | 2011-02-24 | 2011-09-14 | 浙江大学 | Method for detecting ice coating of power line based on capacity effect |
| GB201404462D0 (en) * | 2014-03-13 | 2014-04-30 | Rolls Royce Plc | Ice thickness measurement sensor |
| US10660327B2 (en) * | 2015-07-02 | 2020-05-26 | Xiaojun Xing | Multilayer insulation of biological samples and cooling by immersing in a cryogenic liquid for cryopreservation |
| CN205300491U (en) * | 2015-10-27 | 2016-06-08 | 艾礼富电子(深圳)有限公司 | Ice sheet thickness sensor and refrigeration equipment |
| CN105548285B (en) * | 2015-12-28 | 2018-06-12 | 中国电子科技集团公司第四十九研究所 | A kind of method using slotting finger micro-structure condenser type thin ice sensor measurement thin ice |
| CN106289038B (en) * | 2016-09-19 | 2019-08-09 | 柳玉翠 | Ice maker ice thickness detection circuit and detection method |
| CN106979563A (en) * | 2017-05-10 | 2017-07-25 | 广东美的制冷设备有限公司 | Air conditioner and its chassis icing detection means and method |
| WO2018205388A1 (en) * | 2017-05-10 | 2018-11-15 | 广东美的制冷设备有限公司 | Air conditioner, and control device and method for air conditioner |
| CN107607439B (en) * | 2017-08-22 | 2020-03-27 | 西安工程大学 | Automatic identification device and identification method for icing type of power transmission conductor |
| CN110082632A (en) * | 2019-02-21 | 2019-08-02 | 国网山东省电力公司临沂供电公司 | A kind of transmission line malfunction monitoring device and method |
| CN109752282A (en) * | 2019-02-28 | 2019-05-14 | 西安工程大学 | Icing sensor and its transmission line icing monitoring system and monitoring method of application |
| CN110146008B (en) * | 2019-05-16 | 2021-02-12 | 西安工程大学 | Method for monitoring icing parameters and states based on interdigital capacitive sensor |
-
2020
- 2020-07-31 CN CN202010758540.1A patent/CN111928768B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1737490A (en) * | 2005-09-01 | 2006-02-22 | 太原理工大学 | Condenser type ice layer thickness sensor and detecting method thereof |
| CN101285673A (en) * | 2008-06-06 | 2008-10-15 | 太原理工大学 | Capacitance ratio type ice-covering thickness sensor and its detection method |
| CN103016099A (en) * | 2012-12-25 | 2013-04-03 | 中国第一汽车股份有限公司 | Ventilating and heating system of crankcase |
| CN103292683A (en) * | 2013-05-31 | 2013-09-11 | 太原理工大学 | Capacitive sensing type detection device and detection method for ice cover thickness of overhead power transmission lines |
| CN104197205A (en) * | 2014-09-17 | 2014-12-10 | 太原理工大学 | Pipe network blocking detecting device |
| CN204989497U (en) * | 2015-09-22 | 2016-01-20 | 江西飞尚科技有限公司 | Contact ice sheet detects sensor |
| CN106500582A (en) * | 2016-11-23 | 2017-03-15 | 合肥市芯海电子科技有限公司 | A kind of solidifying frost detection means of refrigerator condenser type and detection method |
| CN109974571A (en) * | 2018-12-24 | 2019-07-05 | 天津天商酷凌科技有限公司 | A kind of condenser type multiple-effect frost sensor that evaporator has |
| CN109764913A (en) * | 2019-02-22 | 2019-05-17 | 昆明大蚯蚓科技有限公司 | Pavement conditions detection device and method |
| CN209764004U (en) * | 2019-05-24 | 2019-12-10 | 西安工程大学 | Icing thickness measuring device based on variable-medium capacitive sensor |
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|---|---|
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