CN103398747A - Gas flowmeter and application method thereof - Google Patents

Abstract

The invention provides a gas flowmeter. The gas flowmeter comprises a flow guide filter element and a laminar flow generator, wherein the flow guide filter element and the laminar flow generator are sequentially arranged inside a tubular shell in the direction of a gas flow, and a differential pressure transducer and a data processing unit are arranged outside the tubular shell; the side wall of the tubular shell is provided with two pressure taking channels in the radial direction, the two pressure taking channels correspond to two sensing ends of the differential pressure transducer, and the two pressure taking channels are located in front of and behind the laminar flow generator; the main body of the laminar flow generator is multi-micropore channels, the section of each multi-micropore channel is in a grid shape, all the multi-micropore channels are parallel to one another and mutually insulated, so that the gas flow to be measured passes through the laminar flow generator in a laminar flow state. The gas flowmeter has the advantages of being small in size, stable in work and high in metering accuracy.

Description

A kind of gas meter and application process thereof

Technical field

The present invention relates to a kind of measurement of gas flow device.

Background technology

In the market for rock gas trade settlement aspect, in, the main flow flowmeter of low discharge metering is diaphragm gas meter.

The defect of diaphragm gas meter: volume is large, and difficulty is installed; Complex structure, failure rate is high; Transmission membrane intensity is limited, can not be high pressure resistant; There is no temperature, pressure compensation, so accuracy is low.

Summary of the invention

The invention provides a kind of gas meter, volume is little, working stability, the accuracy of measuring are high.

The solution of the present invention is as follows:

A kind of gas meter, be included in the water conservancy diversion filtering element and the laminar flow artificial body for generating that in tubular shell, along airflow direction, set gradually, in the outside of tubular shell, differential pressure pickup and data processing unit is installed; Sidewall at tubular shell radially offers two place's pressure passages, corresponds respectively to two induction end of differential pressure pickup, and described two place's pressure passages lay respectively at the place ahead and the rear of laminar flow artificial body for generating; The main body of described laminar flow artificial body for generating is that cross section is latticed many micro channels, and the parallel and mutual isolation of each micro channel, so that air-flow to be measured passes through this laminar flow artificial body for generating with laminar condition.

Based on above-mentioned basic technical scheme, the present invention has also done following optimization and has limited and improve:

Above-mentioned laminar flow artificial body for generating can adopt the stainless steel double-layer plate to roll and form, wherein one deck of described stainless steel double-layer plate is that thickness is less than the 0.1mm corrugated plate, another layer is the smooth plates of thickness less than corrugated plate, between the ripple of corrugated plate and smooth plates, form described many micro channels, the ripple radius of corrugated plate is 1-3mm.

Above-mentioned laminar flow artificial body for generating also can adopt a plurality of stainless steel capillary boundlings to form, and the caliber of stainless steel capillary is 1～3mm, and wall thickness is 0.05～0.15mm.

Above-mentioned laminar flow artificial body for generating is directly fixed in a sleeve pipe, by this sleeve pipe, is installed in described tubular shell.Sleeve pipe inner laminar flow artificial body for generating two ends respectively have several pressure ports of circle, and two circle pressure ports lead to respectively two place's pressure passages of tubular shell.

Outside at tubular shell also is equipped with absolute pressure sensor, and its pressure survey probe and differential pressure pickup are shared the pressure passage.

Outside at tubular shell also is equipped with temperature sensor, the corresponding temp probe that offers passage cut-in temperature sensor of the sidewall of tubular shell.

Application above-mentioned gas flowmeter carries out gas flow measurement, can be with reference to following steps:

(1) install with gas flow measurement scope to be measured adapt the laminar flow artificial body for generating, according to formula Δ P=K ₁μ Q+K ₂ρ Q ²Demarcate this gas meter, draw COEFFICIENT K ₁, K ₂Value; Wherein, Δ P is the pressure differential at laminar flow artificial body for generating two ends, and Q is real-time traffic, and μ is the kinetic viscosity of fluid media (medium);

(2) this gas meter of airflow passes to be measured, gas meter obtain pressure differential deltap P before and after the laminar flow artificial body for generating, calculate according to the following formula real-time traffic Q

$Q=\sqrt{{\left(\frac{K_1\mathrm{\&mu;}}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}\right)}^2+\frac{\mathrm{\&Delta;P}}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}}-\frac{K_1\mathrm{\&mu;}}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}},$ Wherein:

The density of tested gas under ρ-condition of work;

K ₁, K ₂-demarcated the coefficient relevant with the laminar flow flowmeter physical dimension that obtains;

The kinetic viscosity of μ-fluid media (medium).

The present invention has following advantage:

This small product size is little, and level, vertical direction all can conveniently be installed; The overall installation size only is equivalent to the length of the domestic water meter of DN25.

This flowmeter accuracy of measuring is high, compact overall structure, and outside does not connect spool, and inside does not have moving element, failure rate is low; With diaphragm gas meter, comparing can be at high pressure operation more.

The compact overall structure of this product design, rationally distributed.According to application demand, can be in little space integrated pressure, temperature and flow measuring element, realize temperature, press compensate function and the various functions such as demonstration, storage and output.

Designed the laminar flow element sleeve pipe, be convenient for changing the laminar flow artificial body for generating, to adapt to the different flow measurement range.

Further at sleeve pipe inner laminar flow artificial body for generating two ends, respectively have several pressure ports of circle, two circle pressure ports lead to respectively two place's pressure passages of tubular shell accordingly, have formed the ring casing pressure, evenly pressure, and be difficult for stopping up.

The accompanying drawing explanation

Fig. 1 is gas meter principle of work schematic diagram of the present invention.

Wherein, 1-flow integrator; 2-water conservancy diversion filtering element; 3-laminar flow artificial body for generating; 4-flowmeter tubulose housing; The 5-temp probe.

Fig. 2 is laminar flow artificial body for generating diagrammatic cross-section.

Embodiment

Gas meter principle of work of the present invention is as shown in Figure 1: measured gas flow, when flowmeter, at first passes through the water conservancy diversion filtering element, filters out the impurity in gas, and air-flow is carried out to rectification, making flow stable.Air-flow is during through the laminar flow artificial body for generating, and owing to there being frictional resistance, therefore produce the pressure loss at its two ends, less than 2300 the time, this pressure loss is directly proportional to gas flow rate when the Reynolds number of Fluid Flow in A.Namely

Velocity formula: $\stackrel{-}{v}=\frac{c}{\mathrm{\&mu;}}\&CenterDot;\mathrm{\&Delta;P}$

In formula:

The mean flow rate of-fluid;

The pressure differential at Δ P-laminar flow artificial body for generating two ends;

The kinetic viscosity of μ-fluid media (medium)

The constant that c-is relevant with physical dimension.

Flow formula: $\stackrel{-}{Q}=A\&CenterDot;\frac{c}{\mathrm{\&mu;}}\&CenterDot;\mathrm{\&Delta;P}$

In formula:

Average discharge in-pipeline

The A-cross-section of pipeline is long-pending.

In fact, gas produces two parts resistance when flowing through the laminar flow artificial body for generating: a part is the friction force that causes due to gas viscosity, this friction force relevant with the kinetic viscosity of fluid and under low flow conditions (Reynolds number is less than 2300) to flow velocity, be directly proportional; Another part is the inertial force that causes due to throttling, the generation of throttling is that the grain direction that causes due to laminar flow artificial body for generating material wall thickness changes and the stagnation of fluid particle, relevant with the density of fluid according to this inertial force of Bernoulli equation, and to square being directly proportional of flow velocity.It is poor in the static pressure of laminar flow artificial body for generating two ends generation that this two parts resistance sum is gas, and its mathematic(al) representation is as shown in (2) formula.

ΔP=K ₁μQ+K ₂ρQ ²?（3）

In formula: the density of tested gas under ρ-condition of work;

K ₁, K ₂-the coefficient relevant with the laminar flow flowmeter physical dimension.

(3) formula is solved, obtain the expression formula of the volume flow Q under working condition.

$Q=\sqrt{{\left(\frac{K_1\mathrm{\&mu;}}{{2\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}\right)}^2+\frac{\mathrm{\&Delta;P}}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}}-\frac{K_1\mathrm{\&mu;}}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}---\left(4\right)$

An embodiment as shown in Figure 1, 2, this gas meter, be included in the water conservancy diversion filtering element and the laminar flow artificial body for generating that in tubular shell, along airflow direction, set gradually, the laminar flow artificial body for generating is directly fixed in a sleeve pipe, by this sleeve pipe, is installed in described tubular shell.In the outside of tubular shell, differential pressure pickup and data processing unit are installed; Sidewall at tubular shell radially offers two place's pressure passages, corresponds respectively to two induction end of differential pressure pickup, and this two places pressure passage lays respectively at the place ahead and the rear of laminar flow artificial body for generating; The main body of laminar flow artificial body for generating is that cross section is latticed many micro channels, and the parallel and mutual isolation of each micro channel, so that air-flow to be measured passes through this laminar flow artificial body for generating with laminar condition.

Outside at tubular shell also is equipped with absolute pressure sensor and temperature sensor, and the pressure survey probe of absolute pressure sensor and differential pressure pickup are shared the pressure passage, the corresponding temp probe that offers passage cut-in temperature sensor of the sidewall of tubular shell.

Laminar flow artificial body for generating of the present invention can have following two kinds of production methods at least:

Method for making 1: laminar flow element is by two-layer shape difference, and thickness rolls and forms less than the stainless sheet steel of 0.1mm.Wherein one deck is that another layer is the smooth plates that thickness is less through the corrugated plate of special thermal treatment and rolling mill practice making.Requirement is: when air-flow process laminar flow element, the Reynolds number that its each aperture inner fluid flows is less than 2300, and making to flow is in laminar condition.Reynolds number (Re relevant to fluid viscosity, flow velocity and micro-pore diameter _d=vd/ μ).Measuring media can be according to flow measurement range after determining, the calculative determination micro-pore diameter so that Reynolds number in 2300.

Method for making 2: laminar flow element is to be formed by a plurality of stainless steel capillary boundlings.The caliber scope of stainless steel capillary: (1-3) mm, wall thickness range: (0.05-0.15) mm.Requirement is: when air-flow process laminar flow element, the Reynolds number that its each aperture inner fluid flows is less than 2300, and making to flow is in laminar condition.

Based on aforementioned principles, use first this gas meter, can first to this gas meter, demarcate, namely install with gas flow measurement scope to be measured adapt the laminar flow artificial body for generating, according to formula Δ P=K ₁μ Q+K ₂ρ Q ²Demarcate this gas meter, wherein, Δ P is the pressure differential at the laminar flow artificial body for generating two ends that record, and Q is known real-time traffic, and μ is the kinetic viscosity of known fluid media (medium); Draw COEFFICIENT K ₁, K ₂Value;

Then can carry out gas flow measurement: this gas meter of airflow passes to be measured, gas meter obtain pressure differential deltap P before and after the laminar flow artificial body for generating, calculate according to the following formula real-time traffic Q

$Q=\sqrt{{\left(\frac{K_1\mathrm{\&mu;}}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}\right)}^2+\frac{\mathrm{\&Delta;P}}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}}}-\frac{K_1\mathrm{\&mu;}}{2{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00003633425800011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{\&rho;}},$ Wherein:

The density of tested gas under ρ-condition of work;

K ₁, K ₂-demarcated the coefficient relevant with the laminar flow flowmeter physical dimension that obtains;

The kinetic viscosity of μ-fluid media (medium).

Claims (7)

1. a gas meter, is characterized in that: be included in the water conservancy diversion filtering element and the laminar flow artificial body for generating that in tubular shell, along airflow direction, set gradually, in the outside of tubular shell, differential pressure pickup and data processing unit be installed; Sidewall at tubular shell radially offers two place's pressure passages, corresponds respectively to two induction end of differential pressure pickup, and described two place's pressure passages lay respectively at the place ahead and the rear of laminar flow artificial body for generating; The main body of described laminar flow artificial body for generating is that cross section is latticed many micro channels, and the parallel and mutual isolation of each micro channel, so that air-flow to be measured passes through this laminar flow artificial body for generating with laminar condition.

2. gas meter according to claim 1, it is characterized in that: described laminar flow artificial body for generating adopts the stainless steel double-layer plate to roll and forms, wherein one deck of described stainless steel double-layer plate is that thickness is less than the 0.1mm corrugated plate, another layer is the smooth plates of thickness less than corrugated plate, between the ripple of corrugated plate and smooth plates, form described many micro channels, the ripple radius of corrugated plate is 1-3mm.

3. gas meter according to claim 1 is characterized in that: described laminar flow artificial body for generating adopts a plurality of stainless steel capillary boundlings to form, and the caliber of stainless steel capillary is 1～3mm, and wall thickness is 0.05～0.15mm.

According to claim 1 to 3 arbitrary described gas meter, it is characterized in that: described laminar flow artificial body for generating is directly fixed in a sleeve pipe, and this sleeve pipe is installed in described tubular shell; Sleeve pipe inner laminar flow artificial body for generating two ends respectively have several pressure ports of circle, and two circle pressure ports lead to respectively two place's pressure passages of tubular shell.

According to claim 1 to 3 arbitrary described gas meter, it is characterized in that: the outside at tubular shell also is equipped with absolute pressure sensor, its pressure survey probe and differential pressure pickup are shared the pressure passage.

According to claim 1 to 3 arbitrary described gas meter, it is characterized in that: the outside at tubular shell also is equipped with temperature sensor, the corresponding temp probe that offers passage cut-in temperature sensor of the sidewall of tubular shell.

7. apply the method that gas meter as claimed in claim 1 carries out gas flow measurement for one kind, comprise the following steps:

(1) install with gas flow measurement scope to be measured adapt the laminar flow artificial body for generating, according to formula Δ P=K ₁μ Q+K ₂ρ Q ²Demarcate this gas meter, draw COEFFICIENT K ₁, K ₂Value; Wherein, Δ P is the pressure differential at laminar flow artificial body for generating two ends, and Q is real-time traffic, and μ is the kinetic viscosity of fluid media (medium);

(2) this gas meter of airflow passes to be measured, gas meter obtain pressure differential deltap P before and after the laminar flow artificial body for generating, calculate according to the following formula real-time traffic Q

$Q=\sqrt{{\left(\frac{K_1\mathrm{\&mu;}}{{2K}_2\mathrm{\&rho;}}\right)}^2+\frac{\mathrm{\&Delta;P}}{K_2\mathrm{\&rho;}}}-\frac{K_1\mathrm{\&mu;}}{2K_2\mathrm{\&rho;}},$ Wherein:

The density of tested gas under ρ-condition of work;

K ₁, K ₂-demarcated the coefficient relevant with the laminar flow flowmeter physical dimension that obtains;

The kinetic viscosity of μ-fluid media (medium).

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