CN1584514A - Computer gas volume metering method and device for natural gas fuel cylinder of vehicle - Google Patents

Abstract

A device consists of monoithic computer, temperature measuring unit on cylinder wall, pressure measuring unit on tube between pressured release valve and gas cylinder, man-machine component and a display. It is featured as connecting output end of the two units to input end of A/D conventer separately for transmitting digital value to monolithic computer.

Description

The gas-fueled vehicles gas cylinder deposit tolerance computing machine metering method and device

Technical field:

The present invention relates to gas-fueled vehicles, what be specifically related to the gas-fueled vehicles gas cylinder deposits tolerance computing machine metering method and device.

Background technology:

Along with the pay attention to day by day of modern society to environmental protection, the eco-friendly car that uses rock gas to act as a fuel, promptly gas-fueled vehicles are subjected to people's favor day by day.The gas-fueled vehicles fuelled with natural gas does not produce toxic harmful exhaust gas when travelling, rock gas is stored in the gas cylinder with the pressure gas state, and in use, the bottle internal gas pressure changes between 2-20MPa.But, variation of ambient temperature influences highly significant to the gas cylinder internal pressure, existing tensimeter reckons without the influence of temperature variation to the gas cylinder internal pressure, thereby can not show and deposit tolerance and examination bicycle air consumption in the vehicle gas cylinder really, also is difficult in time find the vehicle natural gas leaking.Owing to lack measurement means, do not see the measuring apparatus that is fit to gas-fueled vehicles now both at home and abroad as yet, can't understand vehicle deposits tolerance really and makes gas consumption, bring many inconvenience for the gas-fueled vehicles user, the metering method of depositing tolerance and the device of the suitable gas-fueled vehicles gas cylinder of exploitation are the task of top priority for this reason.

Summary of the invention:

One of purpose of the present invention is will provide to consider the influence of temperature variation to the gas cylinder internal pressure, thereby can measure the computer metering method of depositing tolerance of gas-fueled vehicles gas cylinder comparatively accurately.

Two of purpose of the present invention is computer metering devices of depositing tolerance that the gas-fueled vehicles gas cylinder that can implement metering method described in one of purpose will be provided.

For realizing one of purpose of the present invention, the solution that the present invention adopts is that described metering method may further comprise the steps:

After a, opening power begin, the single-chip microcomputer initialize routine;

B, single-chip microcomputer output sample command are to A/D converter;

C, single-chip microcomputer read measured temperature T from A/D converter _n(℃) and pressure measuring value P _n(kPa);

D, single-chip microcomputer are according to the corresponding P of pressure measuring value _nThe pressure factorial experiment value Z that contracts;

E, single-chip microcomputer read the keyboard options button;

F, read keyboard options button 1, then the single-chip microcomputer working procedure 1, by formula promptly $M=\frac{(P_0+P_n)V{M}_{\mathrm{mol}}}{\mathrm{ZR}(273.15+T_n)}$ Calculate the gas storage quality;

G, read keyboard options button 2, then the single-chip microcomputer working procedure 2, by formula promptly $V_i=\frac{(P_0+P_n)(273.15+T_i)V}{Z{P}_0(273.15+T_n)}$ Calculate gas storage standard state

Volume;

H, single-chip microcomputer output to display with operation result; In the formula:

The quality (kg) of gas in M-gas bomb

P ₀Air pressure under the-standard state is 101.325 (kPa)

P _nThe inside and outside differential pressure measurement value (kPa) of-gas bomb

V-gas bomb volume (m ³)

M _Mol-get the rock gas molecular weight, get 18.4

Z-compressibility factor experiment value, corresponding P _nValue, scope are 0.98～1.25

R-gas law constant is 8.31J/molK

T _nGas thermometry value in the-gas bomb (℃)

V _i-rock gas standard state volume (m ³)

T _i-rock gas standard state temperature (℃).

For realizing two of purpose of the present invention, the solution that the present invention adopts is, described measuring apparatus comprises that a temperature measuring equipment that is arranged on the gas bomb wall and one are arranged on the pressure test device on the pipeline between automobile reduction valve and the gas bomb, also comprise:

A single machine unit, described single machine unit mainly comprise a computing and processing microprocessor, deposit the program internal memory of application program, the IO interface of depositing the data-carrier store of parameter and data and being used to transmit data, described central microprocessor, program internal memory, data-carrier store, and IO interface is connected by data bus, address bus and control bus;

One is used for the display that the result shows, described display is connected with data output interface among the single machine unit;

One is used to select to show that the gas storage quality shows that still the button of gas storage standard state volume is provided with circuit, and described button is provided with circuit and is connected with Data Input Interface among the single machine unit;

The A/D converter and an A/D converter that is used for the input pressure simulating signal that is connected with the pressure tester signal output part that are used for the input temp analog signals that is connected with the temperature measuring equipment signal output part, described A/D converter is connected with the single-chip data input interface.

Owing to adopt technique scheme, gas-fueled vehicles gas cylinder provided by the invention deposit tolerance computing machine metering method and device has such beneficial effect, promptly, used the gas equation principle, and one-chip computer introduced measurement instrument, fully take into account the influence of temperature variation, thereby can show and deposit tolerance in the vehicle gas cylinder really the gas cylinder internal pressure.

Description of drawings:

Fig. 1: be program flow chart of the present invention

Fig. 2: be basic device schematic block diagram of the present invention

Embodiment:

The invention will be further described below in conjunction with accompanying drawing:

The present invention---gas-fueled vehicles gas cylinder deposit tolerance computing machine metering method and device, its ultimate principle is to utilize the state equation of ideal gas.

That is, when quality is M, molal weight is M _MolIdeal gas when being in equilibrium state, its P, V, the relational expression between the T is:

$\mathrm{PV}=\frac{M}{M_{\mathrm{mol}}}\mathrm{RT}---\left(1\right)$

R-molar gas constant, R=8.31J/molK in International System of Units

P-gas pressure intensity (Pa)

M-gaseous mass (Kg)

V-gas volume (m ³)

But, real gas,, pressure not too high in density not too big (with atmospheric pressure relatively) and the scope of temperature not too low (with the room temperature comparison) in, could observe the state equation of ideal gas, therefore, when using The Ideal-Gas Equation, must consider the feature of real gas and give necessary correction.

In the present invention, Z is revised by compressibility factor, and Z is an experiment value, and its scope is 0.98～1.25.

That is, by revised gas equation:

$\mathrm{PV}=Z\frac{M}{M_{\mathrm{mol}}}\mathrm{RT}---\left(2\right)$

Can derive: $M=\frac{(P_0+P_n)V{M}_{\mathrm{mol}}}{\mathrm{ZR}(273.15+T_n)}$

The standard state of considering rock gas (is made as P ₁, V ₁, T ₁) and a bottle inner equilibrium state (be made as P ₂, V ₂, T ₂), by formula (1) and formula (2), as can be known:

$\frac{P_1{V}_1}{{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="A20041002483200111.png"\; state="\{\{state\}\}">T</figure-callout>}}_1}=\frac{P_2{V}_2}{\mathrm{<figure-callout\; id="2"\; label="Z\; T"\; filenames="A20041002483200111.png"\; state="\{\{state\}\}">Z</figure-callout>}{T}_{}{}_2}=\frac{M}{M_{\mathrm{mol}}}R$

Can derive:

$V_i=\frac{(P_0+P_n)(273.15+T_i)V}{Z{P}_0(273.15+T_n)}$

The quality (kg) of gas in M-gas bomb

P ₀Air pressure under the-standard state is 101.325 (kPa)

P _nThe inside and outside differential pressure measurement value (kPa) of-gas bomb

V-gas bomb volume (m ³)

M _Mol-get the rock gas molecular weight, get 18.4

Z-compressibility factor experiment value, corresponding P _nValue, scope are 0.98～1.25

R-gas law constant is 8.31J/molK

T _n-gas thermometry value (℃)

V _i-rock gas standard state volume (m ³)

T _i-rock gas standard state temperature (℃)

Fig. 1 is a program flow chart of the present invention.

Concrete implementation step is:

Earlier single-chip microcomputer is programmed, with application program and default initial parameter: gas-fueled vehicles gas bomb volume V (m ³), rock gas molecular weight, rock gas standard state temperature T _i, the experiment value of compressibility factor Z deposits in the program internal memory of single-chip microcomputer;

Opening power, the single-chip microcomputer initialize routine, the output sample command is to A/D converter, and A/D converter is from the temperature measuring equipment that is arranged on the gas bomb wall and be arranged on the measured temperature T that the pressure tester up-sampling on the pipeline is obtained between automobile reduction valve and the gas bomb _n(℃) and pressure measuring value P _n(kPa) analog quantity is converted to the data-carrier store of digital quantity input single-chip microcomputer;

Single-chip microcomputer reads measured value, according to the corresponding P of pressure measuring value _nThe pressure factor Z value that contracts;

Single-chip microcomputer reads the keyboard options button, reads keyboard options button 1, and then the single-chip microcomputer working procedure 1, by formula promptly $M=\frac{(P_0+P_n)V{M}_{\mathrm{mol}}}{\mathrm{ZR}(273.15+T_n)}$ Calculate the gas storage quality, read keyboard options button 2, then the single-chip microcomputer working procedure 2, by formula promptly $V_i=\frac{(P_0+P_n)(273.15+T_i)V}{Z{P}_0(273.15+T_n)}$ Calculate gas storage standard state volume;

Single-chip microcomputer outputs to display with operation result, the display display result.

Fig. 2 is a principle of work schematic block diagram of the present invention.

Core component of the present invention is a single machine unit.

Measure assembly and comprise that a temperature measuring equipment that is arranged on the gas bomb wall and one are arranged on the pressure test device on the pipeline between automobile reduction valve and the gas bomb, described temperature measuring equipment can use common temperature measuring equipment such as thermopair etc., described pressure tester can be used pressure tester commonly used such as differential pressure gauge etc., each is connected the signal output part of temperature measuring equipment and pressure tester with the signal input part of an A/D converter respectively, and A/D converter will be measured the analogue value that assembly records and be converted to digital value and import single-chip microcomputer.

The man-machine interface parts comprise that one is used to select show that the gas storage quality shows that still the button of gas storage standard state volume is provided with circuit and one and is used for the display that the result shows, described button is provided with circuit and is connected with Data Input Interface among the single machine unit; Described display is connected with data output interface among the single machine unit, and described display can use common display such as LCD or digital luminotron etc.

The present invention removes the tolerance of depositing that can be used to measure the gas-fueled vehicles gas cylinder, and the temperature that also can be used for other is measured for the tolerance of depositing of the bigger accumulator unit of metering precision influence.

Claims (2)

1, the computer metering method of depositing tolerance of gas-fueled vehicles gas cylinder is characterized in that comprising following steps:

After a, opening power begin, the single-chip microcomputer initialize routine;

B, single-chip microcomputer output sample command are to A/D converter;

C, single-chip microcomputer read measured temperature T from A/D converter _n(℃) and pressure measuring value P _n(kPa);

D, single-chip microcomputer are according to the corresponding P of pressure measuring value _nThe pressure factorial experiment value Z that contracts;

E, single-chip microcomputer read the keyboard options button;

F, read keyboard options button 1, then the single-chip microcomputer working procedure 1, by formula promptly $M=\frac{(P_0+P_n)V{M}_{\mathrm{mol}}}{\mathrm{ZR}(273.15+T_n)}$ Calculate the gas storage quality;

G, read keyboard options button 2, then the single-chip microcomputer working procedure 2, by formula promptly $V_i=\frac{(P_0+P_n)(273.15+T_i)V}{Z{P}_0(273.15+T_n)}$ Calculate gas storage standard state volume;

H, single-chip microcomputer output to display with operation result;

In the formula:

The quality (kg) of gas in the M-gas bomb

P ₀Air pressure under the-standard state is 101.325 (kPa)

P _nThe inside and outside differential pressure measurement value (kPa) of-gas bomb

V-gas bomb volume (m ³)

M _Mol-get the rock gas molecular weight, get 18.4

Z-compressibility factor experiment value, corresponding P _nValue, scope are 0.98～1.25

The R-gas law constant is 8.31J/molK

T _nGas thermometry value in the-gas bomb (℃)

V _i-rock gas standard state volume (m ³)

T _i-rock gas standard state temperature (℃).

2, the computer metering device of depositing tolerance of gas-fueled vehicles gas cylinder comprises that a temperature measuring equipment that is arranged on the gas bomb wall and one are arranged on the pressure test device on the pipeline between automobile reduction valve and the gas bomb, is characterized in that also comprising:

A single machine unit, described single machine unit mainly comprise a computing and processing microprocessor, deposit the program internal memory of application program, the IO interface of depositing the data-carrier store of parameter and data and being used to transmit data, described central microprocessor, program internal memory, data-carrier store, and IO interface is connected by data bus, address bus and control bus;

One is used for the display that the result shows, described display is connected with data output interface among the single machine unit;

One is used to select to show that the gas storage quality shows that still the button of gas storage standard state volume is provided with circuit, and described button is provided with circuit and is connected with Data Input Interface among the single machine unit;

The A/D converter and an A/D converter that is used for the input pressure simulating signal that is connected with the pressure tester signal output part that are used for the input temp analog signals that is connected with the temperature measuring equipment signal output part, described A/D converter is connected with the single-chip data input interface.

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