Device for ascertaining a measure of a caloric value of a gas

Patent metadata

Field	Value
Publication number	US-9851317-B2
Application number	US-201414768728-A
Country	US
Kind code	B2
Filing date	Feb 17, 2014
Priority date	Feb 19, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A device for ascertaining a measure of a calorific value of a gas, having a membrane arranged between a first and a second electrode a controllable voltage/current source for generating a control voltage/current between the first and second electrode, and an analyzing device for ascertaining the measure of the calorific value of the gas. By applying the control voltage/current to the first and second electrode, oxygen is transported from an oxygen-containing reference gas into the gas through the membrane and is combusted with combustible components of the gas. The analyzing device ascertains the measure of the calorific value of the gas dependent on the generated control voltage/current a temperature of the membrane, or dependent on an impedance of the membrane.

First claim

The invention claimed is:

1. A device that ascertains a measure of a calorific value of a gas that has combustible components, comprising:
a diaphragm having a first side and a second side that is different than the first side and configured to transport oxygen above a threshold value of a temperature;
a heating apparatus configured to heat the diaphragm;
a first electrode arranged on the first side of the diaphragm in a first environment that contains the gas;
a second electrode arranged on the second side of the diaphragm in a second environment that contains a reference gas, which is different than the gas, with oxygen;
one of a controllable voltage and a controllable current source for generating a respective control voltage or a control current between the first electrode and second electrode for controlling the transporting of the oxygen through the diaphragm; and
an evaluation apparatus configured to ascertain the measure of the calorific value of the gas;
wherein the one of the controllable voltage and the controllable current source generates the respective control voltage or control current such that such a quantity of oxygen is transported through the diaphragm as a function of a level of the control voltage or the control current that the combustible components of the gas burn,
wherein the evaluation apparatus ascertains the measure of the calorific value of the gas as a function of one of a level of a temperature of the diaphragm and an impedance of the diaphragm.

2. The device as claimed in claim 1 , further comprising:
a control apparatus configured to control the one of the controllable voltage source and the controllable current source,
wherein the control apparatus controls the one of the controllable voltage source and the controllable current source in successive time cycles such that during a first duration of each of the time cycles the respective control voltage or control current is not generated, and during a second duration of each of the time cycles, which follows the first duration, the respective control voltage or control current is generated with the level.

3. The device as claimed in claim 2 , comprising:
a voltage measuring apparatus configured to ascertain a voltage level between the first electrode and the second electrode during the first duration of each of the time cycles,
wherein the control apparatus actuates the one of the controllable voltage source and the controllable current source such that the one of the controllable voltage source and the controllable current source generates the level of the respective control voltage or control current during the second duration of each of the time cycles as a function of the voltage level ascertained during the first duration.

4. The device as claimed in claim 2 , wherein:
the control apparatus controls the heating apparatus,
the control apparatus actuates the heating apparatus in successive heating periods such that the heating apparatus is deactivated during a first duration of each heating period and activated during a second duration of each heating period that follows the first duration to heat the diaphragm.

5. The device as claimed in claim 4 , further comprising:
a temperature measuring apparatus for ascertaining a temperature of the diaphragm,
wherein the control apparatus is designed to set a ratio of the first duration and the second duration of each heating period as a function of the temperature of the diaphragm ascertained by the temperature measuring apparatus.

6. The device as claimed in claim 5 ,
wherein the evaluation apparatus evaluates the ratio of the first duration and second duration of each heating period and ascertains the measure of the calorific value of the gas as a function of the ratio.

7. The device as claimed in claim 2 , further comprising:
a measuring apparatus configured to measure the impedance of the diaphragm,
wherein the evaluation apparatus evaluates, during the first duration of each of the time cycles, the impedance measured by the measuring apparatus and ascertains the measure of the calorific value of the gas as a function of the evaluation.

8. The device as claimed in claim 1 , comprising:
a lambda probe that contains the diaphragm, the heating apparatus, and the first electrode and second electrode.

9. The device as claimed in claim 8 ,
wherein the lambda probe is one of a bistable probe and a broadband probe.

10. The device as claimed in claim 8 ,
wherein the lambda probe is a broadband probe that comprises a Nernst cell and a pump cell having a third electrode and a fourth electrode,
wherein the Nernst cell comprises the diaphragm, the first electrode, and the second electrode,
wherein a measuring apparatus for measuring the impedance of the diaphragm is arranged between the third electrode and the fourth electrode.

11. The device as claimed in claim 8 ,
wherein the lambda probe comprises a channel with an inlet opening that feeds the reference gas into the channel,
wherein the second electrode is arranged in the channel, and
wherein a diffusion barrier that inputs the reference gas into the channel is arranged at the inlet opening (ERK) of the channel.

12. A method for ascertaining a measure of a calorific value of a gas that has combustible portions, comprising:
providing a device for ascertaining a calorific value of a gas having a diaphragm having a diaphragm having a first side and a second side that is different than the first side and configured to transport oxygen above a threshold value of a temperature, a heating apparatus configured to heat the diaphragm, a first electrode arranged on the first side of the diaphragm in a first environment that contains the gas; a second electrode arranged on the second side of the diaphragm in a second environment that contains a reference gas, which is different than the gas, with oxygen, one of a controllable voltage and a controllable current source for generating a respective control voltage or a control current between the first electrode and second electrode for controlling the transporting of the oxygen through the diaphragm, and an evaluation apparatus;
arranging the device such that the first electrode is arranged in the first environment and the second electrode is arranged in the second environment;
applying the respective control voltage or the control current between the first electrode and the second electrode with a level such that a quantity of oxygen is transported from the second environment through the diaphragm to the first environment such that the combustible portions of the gas burn;
burning the oxygen in the first environment of the first electrode;
acquiring the measure of the calorific value of the gas by evaluating one of a level of the temperature of the diaphragm or an impedance of the diaphragm during combustion.

13. The method as claimed in claim 12 , further comprising:
measuring a level of the voltage between the first electrode and the second electrode;
regulating the level of the respective control voltage or the control current as a function of the measured voltage level,
wherein the measurement of the voltage level between the first electrode and the second electrode and the regulating of the control voltage or the control current in successive time cycles occurs such that during a first duration of each of the time cycles no respective control voltage or respective control current is applied between the first electrode and the second electrode and the voltage level between the first electrode and the second electrode is measured, and during a second time period of each of the time cycles, which fo

Assignees

• Continental Automotive Gmbh

Inventors

• Grass Phillippe

Classifications

• G01N25/22 Primary

  on combustion or catalytic oxidation, e.g. of components of gas mixtures · CPC title

• G01N27/4065

  Circuit arrangements specially adapted therefor · CPC title

• G01N33/225 Primary

  Gaseous fuels, e.g. natural gas · CPC title