CN201804022U - Penetrating Ultrasonic Flue Velocity Meter - Google Patents

Abstract

The through ultrasonic fume flow rate meter consists of two ultrasonic transceivers and a control circuit, and features that the two ultrasonic transceivers are set separately in the upstream side and the downstream side of the fume pipeline to be measured to form an ultrasonic propagation path in the fume passage, the probe of the ultrasonic transceiver is connected via wire to the control circuit inside the control box, and the axial length direction of the ultrasonic transceiver forms a fixed angle theta with the fume flow rate direction. The control circuit excites the ultrasonic transceivers to generate ultrasonic waves by generating electric signals of 40kHz, and the two ultrasonic transceivers receive and transmit time difference of the ultrasonic waves to calculate the speed of the flue gas fluid; the instantaneous flow rate is determined from the cross-sectional area of the passage. The advantages are that the speed measurement has the advantages of fast response and wide measurement range. The ultrasonic flue gas flow velocity meter is suitable for forming an ultrasonic wave propagation path in a flue gas flow path to measure the flow velocity of flue gas fluid.

Description

Penetrating Ultrasonic Flue Velocity Meter

technical field

The utility model belongs to the measurement of gas flow velocity, in particular to an ultrasonic flue gas velocity measuring instrument which adopts ultrasonic wave to measure flue gas flow, and is applied in the environmental protection monitoring industry. the

Background technique

At present, most of them are used in CEMS systems of thermal power plants and power plants. The detection methods of flue gas flow rate mainly include: Pitot tube for measuring the pressure difference in the fluid, and thermal gas flowmeter for measuring the thermal variable of the fluid. the

The principle of the Pitot tube gas flowmeter is: to measure the flow rate by measuring the pressure. During operation, place the velocity measuring tube at the center of the flue, make the nozzle perpendicular to the flow direction of the flue gas, and measure the relationship between the dynamic pressure and the static pressure at this position. difference, so as to calculate the flow velocity at this point. Existing problems: In order to realize the measurement of flow rate, the instrument needs to be equipped with a differential pressure transmitter, especially in the measurement of small flow rate (10m/s), because the pressure generated by the pitot tube is very small, so for the measurement of low flow rate, the pitot tube gas The flow meter has its own disadvantages: poor accuracy, unable to measure low-speed flue gas, and often blocked. the

The principle of the thermal gas flowmeter is to use the principle of heat conduction to detect the flow rate, that is, to measure the flow rate through the heat exchange relationship between the flowing fluid and the heat source. The mass flow Q can be derived from the ratio of the heating power to the temperature difference of the heat source. Problem: The response speed of the thermal gas flowmeter is relatively long. the

Contents of the invention

The purpose of this utility model is to propose a method for measuring the time required to cross a certain distance in view of the shortcomings of the above-mentioned flowmeter, which involves setting two ultrasonic transceivers on the upwind side and the downwind side of the flue gas pipeline to be measured respectively, through a Ultrasonic transceivers send ultrasonic waves to another ultrasonic transceiver for reception, and then another ultrasonic transceiver sends ultrasonic waves to the former ultrasonic transceiver to receive the time difference required to measure the ultrasonic flow meter of flue gas flow, so as to achieve speed measurement with fast response and wide measurement range. wide advantages. the

The technical scheme of the utility model is that a piercing type ultrasonic flue gas velocity measuring instrument is composed of two ultrasonic transceivers and a control circuit, and the two ultrasonic transceivers are respectively arranged on the upwind side and the downwind side of the measured flue gas pipeline , forming an ultrasonic propagation path in the flue gas passage, the probe of the ultrasonic transceiver is connected to the control circuit in the control box through a wire, and the ultrasonic transceiver is fixed on the flue by its own flange and the flange on the flue gas pipe. Keep the axial directions of the two ultrasonic transceivers at a fixed angle θ with the smoke flow direction. the

The control circuit excites the ultrasonic transceiver to generate ultrasonic waves by generating 40kHz electrical signals. the

The utility model has the advantages that the ultrasonic flue gas velocity measuring instrument is used for measuring the flue gas flow in the flue, and has the advantages of fast response and wide measurement range. It is an ultrasonic flue gas flow meter suitable for forming an ultrasonic propagation path in the flue gas flow path to measure the flow rate of the flue gas fluid. the

Description of drawings

Below in conjunction with accompanying drawing and embodiment, the utility model is further described. the

Fig. 1 is a schematic diagram of the structure of the penetrating ultrasonic flue gas flow meter of the present invention

In the figure, 1-flue, 2-flange on the flue gas pipe, 3-upwind ultrasonic transceiver, 4-upwind ultrasonic probe, 5-downwind ultrasonic probe, 6-flange of ultrasonic transceiver, 7-control Box, 8-downwind ultrasonic transceiver

Detailed ways

It can be seen from Fig. 1 that a penetrating ultrasonic flue gas velocity measuring instrument is composed of two ultrasonic transceivers and a control circuit. On the downwind side of the measured flue gas pipeline, an ultrasonic propagation path is formed in the passage of the flue gas, and the upwind ultrasonic probe 4 and the downwind ultrasonic probe 5 of the ultrasonic transceiver are connected to the control circuits in the respective control boxes 7 by wires, and the ultrasonic transceiver Use its own flange 6 and the flange 2 on the flue gas pipe to fix it on the flue, and keep the axis direction of the two ultrasonic transceivers at a fixed angle θ with the direction of the flue gas flow. The control circuit excites the ultrasonic transceiver to generate ultrasonic waves by generating 40kHz electrical signals. the

The usage method of the utility model is that two ultrasonic transceivers function as a transmitter and a receiver respectively, and when one ultrasonic transceiver is used as a transmitter, the other is used as a receiver. The ultrasonic propagation path formed between the two ultrasonic transceivers forms an angle θ with the flow direction of the fluid. When the ultrasonic wave advances along the direction of fluid flow, its speed becomes faster, and when the ultrasonic wave advances against the direction of fluid flow, its speed becomes slower. Therefore, the control circuit generates a 40kHz electrical signal to excite the ultrasonic transceiver to generate ultrasonic waves, and the control circuit records the time difference between the two ultrasonic transceivers to send and receive ultrasonic transmission through software, and the fluid velocity can be obtained. Calculate the instantaneous flow rate from the cross-sectional area of the flow path. the

Claims (1)

1. one kind to wearing the formula ultrasonic flue gas flow rate meter, constitute by two ultrasonic transmitter-receivers and control circuit, it is characterized in that, two ultrasonic transmitter-receivers are separately positioned on the weather side and the downwind side of tested flue, in the path of flue gas, form ultrasonic wave propagation path, the probe of ultrasonic transmitter-receiver is connected to control circuit in the control enclosure by lead, ultrasonic transmitter-receiver utilizes flange of self and the ring flange on the flue to be fixed on the flue, and the axial length direction of ultrasonic transmitter-receiver becomes fixed angle θ with the flue gas flow rate direction.

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