Gas flow detection sensor circuit for mining pipelines

Abstract

The invention discloses a mining pipeline gas flow detection sensor circuit, including a platinum resistor TR1 and a platinum resistor TR2, wherein the two ends of the platinum resistor TR1 are marked as S1 and S2, respectively, and the two ends of the platinum resistor TR2 are marked as S3 and S4, respectively, and a positive temperature coefficient platinum resistor sensing element is adopted, and its high sensitivity to temperature is utilized. Based on the constant power measurement principle, a 10V voltage is added between S1 and S2 of the platinum resistor TR1 to heat the platinum resistor, and the terminal voltage difference between S2 and S4 is detected and converted by A / D and then entered into a CPU for detection and conversion, so that the flow size can be detected. The invention realizes low flow velocity measurement within the flow velocity range of 0.3-60m / s and low power consumption long-distance transmission of gas flow.

Description

Technical Field

[0001] The invention relates to a mine pipeline gas flow detection sensor circuit, belonging to the technical field of mine monitoring equipment. Background Art

[0002] In order to solve the gas hazards in mines and improve the gas extraction rate, it is necessary to perform high-precision detection of the gas flow extraction volume in the coal mine extraction pipeline. Traditional vortex street measuring instruments are currently widely used. However, since vortex street detection can only generate an oscillation signal after the wind speed exceeds the starting point, the vortex street flow detection equipment of the existing technology can only detect the flow rate range of 4-60m / s, and cannot accurately detect the gas flow in the extraction pipeline at low flow rates, and cannot ensure the safety of coal mine production. Therefore, improving the existing technology to achieve accurate detection of gas flow in the extraction pipeline at low flow rates is of great significance to ensure the safety of coal mine production. Summary of the invention

[0003] The object of the present invention is to provide a mining pipeline gas flow detection sensor circuit, which is based on the constant power measurement principle and adopts two positive temperature coefficient platinum resistance sensor elements to achieve low flow rate measurement of gas flow.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A mining pipeline gas flow detection sensor circuit, including a platinum resistor TR1 and a platinum resistor TR2, wherein the two ends of the platinum resistor TR1 are marked as S1 and S2 respectively, and the two ends of the platinum resistor TR2 are marked as S3 and S4 respectively, the platinum resistor TR1 is a flow detection platinum resistor, and the platinum resistor TR2 is a reference platinum resistor, and also includes a three-terminal reference power supply U4, a three-terminal reference power supply U7, an AD converter U3, a dual operational amplifier U5, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C9, a capacitor C10, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23, a capacitor C24, a capacitor C25, a capacitor C26, a resistor R6, a resistor R7, a resistor R8, a resistor R10, a resistor R11, a resistor R12, a resistor R15, a resistor R51, and a resistor R100;The S2 terminal of the platinum resistor TR1 is connected to a 10V power supply, capacitors C7 and C10 are connected in parallel, one end of the parallel circuit is connected to a 10V power supply, and the other end of the parallel circuit is grounded, the S1 terminal of the platinum resistor TR1 is grounded, pin 1 of the three-terminal reference power supply U7 is the adjustment terminal, pin 2 of the three-terminal reference power supply U7 is the output terminal, pin 3 of the three-terminal reference power supply U7 is the ground terminal, pin 1 of the three-terminal reference power supply U4 is the adjustment terminal, pin 2 of the three-terminal reference power supply U4 is the output terminal, pin 3 of the three-terminal reference power supply U4 is the ground terminal, pins 1 and 3 of the three-terminal reference power supply U7 are connected to -V(D), one end of the resistor R15 is connected to +V(D), and the other end of the resistor R15 is connected to the 2nd pin, one end of capacitor C26 is connected to 2nd pin of three-terminal reference power supply U7, and the other end is connected to -V(D), the S1 end of platinum resistor TR1 is connected to 1IN- end of dual operational amplifier U5, the S2 end of platinum resistor TR1 is connected to 1OUT end of dual operational amplifier U5, the 1IN+ end of dual operational amplifier U5 is connected to 2nd pin of three-terminal reference power supply U7, one end of capacitor C24 is connected to -V(D), the other end of capacitor C24 is connected to 1IN- end of dual operational amplifier U5, one end of resistor R10 is connected to 1OUT end of dual operational amplifier U5, the other end of resistor R10 is connected to 1IN- end of dual operational amplifier U5, and the GND end of dual operational amplifier U5 is connected to -V (D), capacitor C16, capacitor C19, and capacitor C22 are connected in parallel, one end of the parallel circuit is connected to the GND terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded, one end of the resistor R51 is connected to +V(D), and the other end of the resistor R51 is connected to the VCC terminal of the dual operational amplifier U5, capacitor C15, capacitor C18, and capacitor C21 are connected in parallel, one end of the parallel circuit is connected to the VCC terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded, the S3 terminal of the platinum resistor TR2 is connected to the 2IN- terminal of the dual operational amplifier U5, the S4 terminal of the platinum resistor TR2 is connected to the 2OUT terminal of the dual operational amplifier U5, and the two ends of the resistor R11 are respectively connected to the 2 IN-terminal, 2OUT terminal, two ends of capacitor C25 are connected to -V(D) and 2IN-terminal of dual operational amplifier U5 respectively, 2IN+terminal of dual operational amplifier U5 is connected to pin 2 of three-terminal reference power supply U7, pins 1 and 3 of three-terminal reference power supply U4 are connected to -V(A), one end of resistor R12 is connected to +V(A), the other end of resistor R12 is connected to pin 2 of three-terminal reference power supply U4, capacitor C6 and capacitor C23 are connected in parallel, one end of the parallel circuit is connected to pin 2 of three-terminal reference power supply U4, the other end of the parallel circuit is connected to -V(A), one end of resistor R100 is connected to +V(A), the other end of resistor R100 is connected to VDD terminal of AD converter U3; The end is connected to the VDD end of the AD converter U3, capacitors C14, C17, and C20 are connected in parallel, one end of the parallel circuit is connected to the VDD end of the AD converter U3, and the other end of the parallel circuit is connected to -V (A), the GND end of the AD converter U3, The end is connected to -V(A), the REF IN(+) end of the AD converter U3 is connected to pin 2 of the three-terminal reference power supply U4, the REF IN(-) end of the AD converter U3 is connected to -V(A), one end of the capacitor C3 is connected in series with resistor R7 and then connected to the AIN1(+) end of the AD converter U3, one end of the capacitor C4 is connected to -V(A), the other end of the capacitor C4 is connected in series with resistor R8 and then connected to the AIN1(-) end of the AD converter U3, one end of the capacitor C5 is connected between the capacitor C3 and the resistor R7, the other end of the capacitor C5 is connected between the capacitor C4 and the resistor R8, the 1OUT end and the 2OUT end of the dual operational amplifier U5 are respectively connected to the two ends of the capacitor C5, the AIN1(-) end of the AD converter U3 is connected to the AIN2(+) end, the resistor R6 is connected in series with the capacitor C2, one end of the series circuit is connected to -V(A), and the other end of the series circuit is connected to the AIN2(-) end of the AD converter U3, and the DOUT end of the AD converter U3 outputs a digital signal.

[0006] The purpose of the present invention can also be further achieved by the following technical measures:

[0007] In the aforementioned mining pipeline gas flow detection sensor circuit, the model of the dual operational amplifier U5 is LM358.

[0008] Compared with the prior art, the beneficial effects of the present invention are: based on the constant power measurement principle, a positive temperature coefficient platinum resistance sensor element is adopted, and its high sensitivity to temperature is utilized to achieve low flow rate measurement and low power consumption long-distance transmission of gas flow in the range of 0.3-60m / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a circuit diagram of connecting platinum resistors TR1, TR2 and terminal block J5 of the present invention;

[0010] Figure 2 is a signal amplification circuit diagram of the present invention;

[0011] Figure 3 It is the ADC power supply circuit diagram of the present invention;

[0012] Figure 4 It is the AD conversion circuit diagram of the present invention. DETAILED DESCRIPTION

[0013] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. The mining pipeline gas flow detection sensor circuit of the present invention includes a platinum resistor TR1 and a platinum resistor TR2, wherein the two ends of the platinum resistor TR1 are marked as S1 and S2 respectively, and the two ends of the platinum resistor TR2 are marked as S3 and S4 respectively, the platinum resistor TR1 is a flow detection platinum resistor, and the platinum resistor TR2 is a reference platinum resistor. Since the traditional vortex street measuring instrument is currently widely used, but the vortex street detection can only generate an oscillation signal after the wind speed exceeds the starting point, the vortex street flow detection equipment of the prior art can only detect the flow rate range of 4-60m / s, and cannot realize the accurate detection of the gas flow in the extraction pipeline at a low flow rate. The present invention utilizes the sensitivity of the platinum resistor to temperature, based on the constant power measurement principle, and adds a 10V voltage between S1 and S2 of the platinum resistor TR1 to heat the platinum resistor, that is, a heating power P is applied to raise its temperature to T1; the other platinum resistor TR2 is not heated, and is used to monitor the medium temperature, and its temperature is set to T2, so that a temperature difference △T=T1-T2 is generated between the two sensing elements. Place the detection end in the fluid. When the flow rate is zero, △T is the largest. As the flow rate Q increases, the platinum resistor TR1 between S1 and S2 is cooled by the wind, T1 decreases, and △T decreases. Since we use a positive temperature coefficient platinum resistor, the resistance between S1 and S2 decreases as the temperature drops, and the voltage at the S2 end decreases. The voltage difference between the two ends of S2 and S4 can reflect the size of the flow rate Q. Since there will be a certain relationship between the heating power P, the temperature difference △T and the flow rate Q, specifically: P / △T and Q 3 The voltage difference between S2 and S4 is detected and converted by A / D and then sent to CPU for detection and conversion to detect the flow rate.

[0014] When the mining pipeline gas flow detection sensor circuit is implemented specifically, a three-terminal reference power supply U4, a three-terminal reference power supply U7, an AD converter U3, a dual operational amplifier U5, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C9, a capacitor C10, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23, a capacitor C24, a capacitor C25, a capacitor C26, a resistor R6, a resistor R7, a resistor R8, a resistor R10, a resistor R11, a resistor R12, a resistor R15, a resistor R51, and a resistor R100 are used.

[0015] like Figure 1As shown, the S2 terminal of the platinum resistor TR1 is connected to a 10V power supply, capacitors C7 and C10 are connected in parallel, one end of the parallel circuit is connected to a 10V power supply, the other end of the parallel circuit is grounded, and the S1 terminal of the platinum resistor TR1 is grounded. According to the requirements of the Coal Mine Safety Supervision Letter

[2016] No. 5 of the State Coal Mine Safety Supervision Bureau, in order to achieve long-distance communication for sensors, the power consumption of the sensors must be reduced to achieve long-distance communication. The use of a 10V power supply in the present invention helps to achieve low-power long-distance transmission.

[0016] like Figure 2The diagram shows a circuit diagram of a voltage difference signal amplifier. Pin 1 of the three-terminal reference power supply U7 is the adjustment terminal, pin 2 of the three-terminal reference power supply U7 is the output terminal, and pin 3 of the three-terminal reference power supply U7 is the ground terminal. +V(D) is the positive power supply of the signal amplifier circuit, and -V(D) is the negative power supply of the signal amplifier circuit. The dual operational amplifier U5 of the embodiment of the present invention adopts a dual operational amplifier of model LM358. The 1IN+ terminal is the in-phase input terminal of channel 1 of the dual operational amplifier, the 1IN- terminal is the inverting input terminal of channel 1 of the dual operational amplifier, the 1OUT terminal is the output terminal of channel 1 of the dual operational amplifier, the 2IN+ terminal is the in-phase input terminal of channel 2 of the dual operational amplifier, the 2IN- terminal is the inverting input terminal of channel 2 of the dual operational amplifier, and the 2OUT terminal is the output terminal of channel 2 of the dual operational amplifier. Pin 1 and Pin 3 of the three-terminal reference power supply U7 are connected to -V(D), one end of the resistor R15 is connected to +V(D), the other end of the resistor R15 is connected to Pin 2 of the three-terminal reference power supply U7, one end of the capacitor C26 is connected to Pin 2 of the three-terminal reference power supply U7, and the other end is connected to -V(D), the S1 end of the platinum resistor TR1 is connected to the 1IN- end of the dual operational amplifier U5, the S2 end of the platinum resistor TR1 is connected to the 1OUT end of the dual operational amplifier U5, the 1IN+ end of the dual operational amplifier U5 is connected to Pin 2 of the three-terminal reference power supply U7, one end of the capacitor C24 is connected to -V(D), the other end of the capacitor C24 is connected to the 1IN- end of the dual operational amplifier U5, one end of the resistor R10 is connected to the 1OUT end of the dual operational amplifier U5, the other end of the resistor R10 is connected to the 1IN- end of the dual operational amplifier U5, the GND end of the dual operational amplifier U5 is connected to -V(D), and the capacitor C1 6. Capacitor C19 and capacitor C22 are connected in parallel, one end of the parallel circuit is connected to the GND terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded. One end of the resistor R51 is connected to +V(D), and the other end of the resistor R51 is connected to the VCC terminal of the dual operational amplifier U5. Capacitors C15, C18, and C21 are connected in parallel, one end of the parallel circuit is connected to the VCC terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded. The S3 terminal of the platinum resistor TR2 is connected to the 2IN- terminal of the dual operational amplifier U5, and the S4 terminal of the platinum resistor TR2 is connected to the 2OUT terminal of the dual operational amplifier U5. The two ends of the resistor R11 are respectively connected to the 2IN- terminal and the 2OUT terminal of the dual operational amplifier U5. The two ends of the capacitor C25 are respectively connected to -V(D) and the 2IN- terminal of the dual operational amplifier U5. The 2IN+ terminal of the dual operational amplifier U5 is connected to the 2 pin of the three-terminal reference power supply U7.

[0017] like Figure 3As shown, pin 1 of the three-terminal reference power supply U4 is the adjustment terminal, pin 2 of the three-terminal reference power supply U4 is the output terminal, and pin 3 of the three-terminal reference power supply U4 is the ground terminal. +V(A) is the positive power supply of the AD conversion circuit, -V(A) is the negative power supply of the AD conversion circuit, pins 1 and 3 of the three-terminal reference power supply U4 are connected to -V(A), one end of the resistor R12 is connected to +V(A), and the other end of the resistor R12 is connected to pin 2 of the three-terminal reference power supply U4. Capacitors C6 and C23 are connected in parallel, one end of the parallel circuit is connected to pin 2 of the three-terminal reference power supply U4, and the other end of the parallel circuit is connected to -V(A). As shown Figure 4 As shown in FIG. 1 , a circuit diagram of a voltage difference signal AD conversion is shown. One end of the resistor R100 is connected to +V(A), and the other end of the resistor R100 is connected to the VDD end of the AD converter U3. The end is connected to the VDD end of the AD converter U3, capacitors C14, C17, and C20 are connected in parallel, one end of the parallel circuit is connected to the VDD end of the AD converter U3, and the other end of the parallel circuit is connected to -V (A), the GND end of the AD converter U3, The REF IN (+) terminal of AD converter U3 is connected to the 2nd pin of the three-terminal reference power supply U4. The IN(-) terminal is connected to -V(A), one end of capacitor C3 is connected to -V(A), the other end of capacitor C3 is connected in series with resistor R7 and then connected to the AIN1(+) terminal of AD converter U3, one end of capacitor C4 is connected to -V(A), the other end of capacitor C4 is connected in series with resistor R8 and then connected to the AIN1(-) terminal of AD converter U3, one end of capacitor C5 is connected between capacitor C3 and resistor R7, the other end of capacitor C5 is connected between capacitor C4 and resistor R8, 1OUT terminal and 2OUT terminal of dual operational amplifier U5 are respectively connected to the two ends of capacitor C5, AIN1(-) terminal of AD converter U3 is connected to AIN2(+) terminal, resistor R6 is connected in series with capacitor C2, one end of the series circuit is connected to -V(A), and the other end of the series circuit is connected to AIN2(-) terminal of AD converter U3, and DOUT terminal of AD converter U3 outputs digital signal to CPU unit for detection and conversion, so as to detect the flow rate.

[0018] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A mining pipeline gas flow detection sensor circuit, characterized in that , including platinum resistor TR1 and platinum resistor TR2, wherein the two ends of platinum resistor TR1 are marked as S1 and S2 respectively, and the two ends of platinum resistor TR2 are marked as S3 and S4 respectively, platinum resistor TR1 is a flow detection platinum resistor, and platinum resistor TR2 is a reference platinum resistor, and also includes three-terminal reference power supply U4, three-terminal reference power supply U7, AD converter U3, dual operational amplifier U5, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, capacitor C7, capacitor C9, capacitor C10, capacitor C14, capacitor C15, capacitor C16, capacitor C17, capacitor C18, capacitor C19, capacitor C20, capacitor C21, capacitor C22, capacitor C23, capacitor C24, capacitor C25, capacitor C26, resistor R6, resistor R7, resistor R8, resistor R10, resistor R11, resistor R12, resistor R15, resistor R51, resistor R100;The S2 terminal of the platinum resistor TR1 is connected to a 10V power supply, capacitors C7 and C10 are connected in parallel, one end of the parallel circuit is connected to a 10V power supply, and the other end of the parallel circuit is grounded, the S1 terminal of the platinum resistor TR1 is grounded, pin 1 of the three-terminal reference power supply U7 is the adjustment terminal, pin 2 of the three-terminal reference power supply U7 is the output terminal, pin 3 of the three-terminal reference power supply U7 is the ground terminal, pin 1 of the three-terminal reference power supply U4 is the adjustment terminal, pin 2 of the three-terminal reference power supply U4 is the output terminal, pin 3 of the three-terminal reference power supply U4 is the ground terminal, pins 1 and 3 of the three-terminal reference power supply U7 are connected to -V(D), one end of the resistor R15 is connected to +V(D), and the other end of the resistor R15 is connected to the 2nd pin, one end of capacitor C26 is connected to 2nd pin of three-terminal reference power supply U7, and the other end is connected to -V(D), the S1 end of platinum resistor TR1 is connected to 1IN- end of dual operational amplifier U5, the S2 end of platinum resistor TR1 is connected to 1OUT end of dual operational amplifier U5, the 1IN+ end of dual operational amplifier U5 is connected to 2nd pin of three-terminal reference power supply U7, one end of capacitor C24 is connected to -V(D), the other end of capacitor C24 is connected to 1IN- end of dual operational amplifier U5, one end of resistor R10 is connected to 1OUT end of dual operational amplifier U5, the other end of resistor R10 is connected to 1IN- end of dual operational amplifier U5, and the GND end of dual operational amplifier U5 is connected to -V (D), capacitor C16, capacitor C19, and capacitor C22 are connected in parallel, one end of the parallel circuit is connected to the GND terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded, one end of the resistor R51 is connected to +V(D), and the other end of the resistor R51 is connected to the VCC terminal of the dual operational amplifier U5, capacitor C15, capacitor C18, and capacitor C21 are connected in parallel, one end of the parallel circuit is connected to the VCC terminal of the dual operational amplifier U5, and the other end of the parallel circuit is grounded, the S3 terminal of the platinum resistor TR2 is connected to the 2IN- terminal of the dual operational amplifier U5, the S4 terminal of the platinum resistor TR2 is connected to the 2OUT terminal of the dual operational amplifier U5, and the two ends of the resistor R11 are respectively connected to the 2 IN-terminal, 2OUT terminal, two ends of capacitor C25 are connected to -V(D) and 2IN-terminal of dual operational amplifier U5 respectively, 2IN+terminal of dual operational amplifier U5 is connected to pin 2 of three-terminal reference power supply U7, pins 1 and 3 of three-terminal reference power supply U4 are connected to -V(A), one end of resistor R12 is connected to +V(A), the other end of resistor R12 is connected to pin 2 of three-terminal reference power supply U4, capacitor C6 and capacitor C23 are connected in parallel, one end of the parallel circuit is connected to pin 2 of three-terminal reference power supply U4, the other end of the parallel circuit is connected to -V(A), one end of resistor R100 is connected to +V(A), the other end of resistor R100 is connected to VDD terminal of AD converter U3; The end is connected to the VDD end of the AD converter U3, capacitors C14, C17, and C20 are connected in parallel, one end of the parallel circuit is connected to the VDD end of the AD converter U3, and the other end of the parallel circuit is connected to -V (A), the GND end of the AD converter U3, The REF IN (+) terminal of AD converter U3 is connected to the 2nd pin of the three-terminal reference power supply U4. The IN(-) terminal is connected to -V(A), one end of the capacitor C3 is connected to -V(A), the other end of the capacitor C3 is connected in series with resistor R7 and then connected to the AIN1(+) terminal of the AD converter U3, one end of the capacitor C4 is connected to -V(A), the other end of the capacitor C4 is connected in series with resistor R8 and then connected to the AIN1(-) terminal of the AD converter U3, one end of the capacitor C5 is connected between the capacitor C3 and the resistor R7, the other end of the capacitor C5 is connected between the capacitor C4 and the resistor R8, the 1OUT terminal and the 2OUT terminal of the dual operational amplifier U5 are respectively connected to the two ends of the capacitor C5, the AIN1(-) terminal of the AD converter U3 is connected to the AIN2(+) terminal, the resistor R6 is connected in series with the capacitor C2, one end of the series circuit is connected to -V(A), and the other end of the series circuit is connected to the AIN2(-) terminal of the AD converter U3, the DOUT terminal of the AD converter U3 outputs a digital signal, and the DOUT terminal of the AD converter U3 outputs a digital signal to the CPU unit for detection and conversion to detect the flow rate.

2. The mining pipeline gas flow detection sensor circuit according to claim 1, characterized in that: The model of the dual operational amplifier U5 is LM358.

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