A Totalizer Circuit of Differential Pressure Flowmeter

Abstract

The invention discloses an integrating instrument circuit of a differential pressure flowmeter. The integrating instrument circuit comprises an external power circuit, a 485 driving voltage circuit, a battery power supply circuit, a 4-20mA current flow signal processing circuit, a key circuit, a CPU chip data processing circuit, a 485 communication circuit, a temperature signal acquiring and processing circuit, a pressure signal acquiring and processing signal, a temperature, pressure, standard condition flow rate, working condition flow rate frequency signal output circuit, a concentration sensor signal input circuit, an anti-static circuit and various signal output processing circuits. With the adoption of the integrating instrument circuit of the differential pressure flowmeter, the total volume of gas is measured, and the gas concentration is corrected at the same time.

Description

technical field [0001] The invention relates to an integrator circuit of a differential pressure flowmeter, which belongs to the field of energy measurement and is an indispensable tool in energy management. Background technique [0002] Gas (coalbed methane) is an unconventional natural gas resource that coexists with coal. Coal mine gas is a harmful source of coal and gas outburst and gas explosion accidents in coal mines. In addition, gas pollutes the environment very seriously. The greenhouse effect of its main component CH4 is 26 times that of CO2, and its damage to the ozone layer is 7 times that of CO2. It can be seen that coal mine gas is not only a mineral resource, but also has certain hazards. [0003] The mining and utilization of coal mine gas can realize the safe and efficient development of coal and coal mine gas resources, fundamentally eliminate coal and gas outbursts, gas explosions and other disasters caused by coal seam mining, and can obtain clean energy...

AI Technical Summary

Problems solved by technology

[0004] The extraction and utilization of coal mine gas has become a necessity. However, due to the harsh environment of coal mine gas extraction, with high negative pressure, high humidity, many solid impurities, large flow range, and low flow rate, it is currently used for coal mine gas drainage The current flowmeters mainly include orifice plate flowmeter, precession vortex flowmeter, V-cone flowmeter, and multi-parameter gas drainage meter. None of the above types are fully applicable to the coal mine gas drainage environment, and there are more or less Certain defects: the orifice flowmeter is a traditional flowmeter with small flow range, large pressure loss, and inconvenient installation. The precession vortex flowmeter is mainly used for gas drainage branch pipelines, for drilling holes that are easy to block, and for main pipes Excessive pressure loss, V-cone flowmeter, large pressure loss, has certain hidden dangers, gradually withdraw from the ranks of gas drainage metering instruments, gas drainage multi-parameter measuring instrument, low measurement accuracy, high uncertainty, and has not been calibrated by standard devices , not flow meter

During the use of existing gas drainage metering devices, only the total amount of gas is measured, and the gas concentration is not corrected. The main component of gas gas is methane gas, and different coal mine environments have different methane concentrations. With the prolongation of time, the concentration of methane has decreased, the calculation of gas utilization rate and the judgment of gas drainage, when to stop gas drainage and the allocation of human and material resources for drainage all depend on the evaluation of gas scalar , therefore, the gas flowmeter with density correction is particularly important

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