RU2785879C2 - Membrane gas meter - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to the field of accounting of consumption of hydrocarbon gaseous fuel. A membrane gas meter with a rotational gas distribution valve includes interconnected measuring node, reading device, two membranes kinematically connected to the rotational gas distribution valve, while calculation of a volume of gas passing through the membrane meter is performed by calculation of pulses received from a pair of infrared LEDs installed on an electronic circuit board of the reading device, obtained during the rotation of a helix installed on a gear transmission of a counter of the reading device with functional possibility of determination of a position of the helix in space and determination of a direction of its movement: “clockwise” or “counterclockwise”.

EFFECT: expansion of the arsenal of membrane gas meters, as well as implementation by the invention of its purpose.

1 cl, 6 dwg

Description

The invention relates to the field of accounting for the consumption of hydrocarbon gaseous fuels.

Various membrane gas meters are known from the prior art (see patent RU 2696362 C1, published 08/01/2019, patent RU 189110 U1, published 05/13/2019, patent RU 2416757 C2, published 04/20/2011). However, in order to receive pulses to calculate the volume passing through the gas meter, they use a magnet rotating on the transmitting gear and a reed switch that determines the presentation of the magnet and the transmission of a signal to the EOU.

The task is to eliminate the shortcomings of the prior art. The set technical result consists in expanding the arsenal of membrane gas meters, as well as in the implementation of the appointment.

The problem is solved, and the technical result is achieved by a membrane gas meter with a rotary gas distribution valve, including an interconnected measuring unit, a reading device, two membranes kinematically connected with a rotary gas distribution valve, while the calculation of the volume of gas passing through the membrane meter occurs by calculating pulses received from a pair of infrared LEDs installed on the electronic board of the reading device (hereinafter referred to as EOD, see Fig. 1), received during the rotation of the snail (see Fig. 2, 4) installed on the gear transmission of the reading device counter (see Fig. 3 ), with the functionality of determining the position of the cochlea in space and determining the direction of its movement: “clockwise” or “counterclockwise”.

The drawings show the following:

Fig. 1 - EOU

Fig. 2 - Snail

Fig. 3 - The snail, which is mounted on the transmission gear.

Fig. 4 - A snail that rotates in the hole of the EOU.

Fig.5 - During the rotation of the snail, the determination of the position of the measuring wheel uses a pair of infrared LED / infrared phototransistor.

LEDs with a wavelength of 850 nm are used.

Fig. 6 - Appearance of combination of elements.

pos.1 - EOU

pos.2 - Snail

pos.3 - The upper part of the metal case

pos.4 - The lower part of the metal housing

pos.5 - Transmission gear

pos.6 - EOU body

pos.7 - Steel tape

pos.8 - Diaphragm

pos.9 - Inlet pipe

pos.10 - Outlet pipe

pos.11 - Hole in the EOU for the cochlea

pos.12 - Infrared LEDs

The claimed gas meters with an electronic reading device with the function of correcting the volume of gas by temperature are designed to account for the consumption of hydrocarbon gaseous fuel by displaying on the LCD of the electronic reading device (EDM) of the meter reduced to standard conditions (standard) volume of consumed gas. The EOU of the meter performs temperature correction of the working volume of gas measured by the meter in the operating temperature range from minus -40°C to plus 60°C with a normalized accuracy.

Infrared LED/IR phototransistor pairs are used to determine the position of the measuring wheel. LEDs with a wavelength of 850 nm are used. The phototransistor has a built-in light filter that eliminates the influence of daylight and improves the stable operation of the device. The LEDs operate in a pulsed mode with a period of 126 ms with a pulse duration of about 18 µs. The signal on the LEDs is modulated depending on the supply voltage, which ensures the constancy of the radiated power. Half of the controller supply voltage is used as the threshold voltage at the output of the phototransistors. It is guaranteed that the metrological characteristics of the EDU are maintained at a wheel rotation speed of not more than one revolution per second. Up to a speed of 1.8 revolutions per second, the position of the wheel is determined correctly, but the accuracy of measuring the gas volume decreases. Also, protection is provided against the reverse motion of the wheel and from interference with the operation of the EOU - if the measuring wheel starts to jerk or spin in the opposite direction, then the EOU goes into error mode.

The calculation of the volume of gas Vc, reduced to standard conditions, is carried out according to the formula: Vc=V⋅C, where: V is the volume of gas under operating conditions, m 3; C - correction factor. С=Ра⋅Тс / (Pc⋅T⋅Z), where: Рс, Тс - standard values of absolute pressure and temperature, MPa and K; Pa=Pu+Pb - absolute pressure under operating conditions, MPa (Pi - overpressure, MPa; Pb - barometric pressure, MPa); T=t+273.15 - absolute temperature, K (t - gas temperature under operating conditions, °C); Z is the gas compressibility factor.

The values Pi=0.002 MPa, Ps=Pb=0.101325 MPa, Tc=293.15 K, Z=1 are entered into the electronic counting mechanism upon release from production, unless other values of these values are specified by the customer. Depending on the actual gas pressure in the network and the location of the area, the values of Pu and Pb may change when the meter is put into operation.

EOU captures the input pulses from the measuring mechanism of the gas meter. The value of the gas volume under operating conditions is defined as the product of the number of pulses and the cyclic volume. Signals from temperature sensors are subjected to analog-to-digital conversion. The received codes are used to calculate the current temperature values. The temperature is measured no more than once every 4 seconds during normal operation and once per second in service mode (including during calibration).

EOU of the meter consists of a housing, in the grooves of which the board of the electronic module of the EOU with a liquid crystal nine-digit (99999.9999) display, the cover of the electronic module and the casing is installed. The EOU body is attached to the meter body with two M4 screws. Dust and moisture protective gaskets are installed between the meter case and the EOU case, as well as between the EOU case and the casing. During normal operation of the meter, the indicator displays the current readings of the meter of the standard volume of gas with the dimension "cubic meters" (m3).

The communication board is installed in the board slot of the electronic module of the EOU and is located under the casing. A hole for connecting a communication interface can be located in the bottom surface of the casing.

EOU has two levels of access to the settings, which are implemented by setting the appropriate jumpers:

a jumper located directly on the EOU board under the cover of the electronic module (under the seal of the verifier) switches the meter to a special service mode that allows you to change the factory settings of the device.

jumper (“unlock jumper”) located on the communication board under the casing (under the seals of the organization that installed and commissioned the meter), which allows changing the settings available for change by the user.

On the EOU board, outside the protective cover, there is also a power battery, a connector for connecting the battery to the EOU, and a battery replacement jumper.

EOU can be in the following main modes:

Normal mode of operation;

Service mode of operation;

Error mode;

Indicator test mode;

Low voltage supply mode.

Claims (1)

Membrane gas meter with a rotary gas distribution valve, including an interconnected measuring unit, a reading device, two membranes kinematically connected to a rotary gas distribution valve, characterized in that the calculation of the volume of gas passing through the membrane meter occurs by calculating the pulses received from a pair of infrared LEDs, installed on the electronic board of the reading device, obtained by rotating the snail installed on the gear transmission of the reading device counter with the functionality of determining the position of the snail in space and determining the direction of its movement: “clockwise” or “counterclockwise”.

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