JPH0151776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas analyzer, and more particularly to a gas analyzer that instantaneously measures the concentration (%) (same below weight %) of various component gases of a ternary gas mixture consisting of carbon dioxide, oxygen, and saturated steam. The present invention relates to a gas analysis device for testing water, and more specifically, the device is used for supplying fuel to engines for diving operations.

Determining the concentration (%) of each of the two required component gases in a ternary gas mixture saturated with steam is particularly important when pressure and temperature can vary within a significantly wide range. This is especially necessary if the (%) values have to be measured in as short a time as possible compared to the changes occurring in their concentration (%). One particular application is testing the concentration (%) of carbon dioxide and oxygen in the intake gas mixture of internal combustion engines with exhaust gas recirculation used in diving operations. In order to be able to adjust the oxygen flow to be fed into the circulation path of the internal combustion engine in such a way that the concentration (%) of oxygen in the gas mixture takes its optimum value, it is necessary to recognize these concentrations (%). is essential.

This is not possible with the conventional gas analyzers currently available, and the reasons for this are as follows. That is, the concentration (%) value to be tested cannot be measured instantaneously, and several tens of seconds are required for measurement, and this measurement time cannot be further shortened.

Information about the concentration (%) value of one of the constituent gases of the gas mixture is closely related to the value of the instantaneous pressure, and therefore the latter value must be known with sufficient precision, otherwise the 2, that is, the concentration (%) value of the second gas must be obtained separately,
This would require a separate gas analyzer to measure the concentration (%) of this second gas, making a total of two gas analyzers, which would obviously require additional equipment. This increases complexity and also reduces reliability.

The hassle-free operation of conventional gas analyzers depends on the temperature level of the gas mixture, but above a certain limit the information obtained in practice contains considerable errors.

And a sufficiently pure gas must be present. This is due to the above reasons.

The aim of the invention is to overcome the above-mentioned difficulties by an approach to the above-mentioned problems based on completely different principles.

The present invention provides a gas analyzer for achieving the above object.

That is, the present invention is useful for controlling the fuel supply to an engine operating underwater that is equipped with a fuel supply pipe through which gas containing oxygen gas, carbon dioxide gas, and saturated water vapor as components flows, A gas analyzer that immediately provides a signal indicating the concentration (%) of a gas, comprising temperature testing means having a sensor in the supply pipe that provides a signal T indicating the temperature of the gas; and acoustic propagation velocity in the gas. sound velocity testing means having a sensor in the supply pipe that provides a signal V ^indicative of a calculation means for calculating the value of the product γR of the ratio γ of the constant pressure specific heat to the constant volume specific heat of the gas and the gas constant R at a series of discrete oxygen gas concentrations (%) at a series of discrete temperature values; A storage device that stores in advance the value of the product γR of the ratio γ between constant pressure specific heat and constant volume specific heat of gas and the gas constant R at a series of discrete carbon dioxide concentrations (%) at temperature values; The value of the product of γ and R at each temperature and each gas concentration (%) and the measured signal V,
Compare the value of V ² /T calculated based on T,
The present invention provides a gas analyzer characterized in that it includes means for immediately generating a signal indicating gas concentration (%) based on the relationship V ² /T=γR.

Fundamental to the solution of the technical problem achieved by the invention is the fact that the velocity of sound propagation in a continuous gaseous medium is a function of the gas constant of the gas, as well as of the temperature, according to the following well-known relationship: This is the principle.

V=√ where V=acoustic propagation velocity in the gas mixture [m・
sec ^-1 ] γ = ratio of specific heat at constant pressure to specific heat at constant volume in the gas mixture
c _P /c _V R = Characteristic constant of the gas mixture [m ² sec ^-2 〓 ^-1 ] T = Absolute temperature of the gas mixture [〓] From the temperature of the gas mixture and the acoustic propagation velocity, γR = V ² /T. A quantity value can be derived, which quantity is a function of the parameters of the gas mixture, ie the concentration (in %) of each component exhibiting known physical and thermodynamic properties. Therefore, these concentrations (%)
The values of can be determined immediately and simultaneously.

In the case of a gas mixture having two components (carbon dioxide and oxygen), the relationship γR = γ ₁ R ₁ p ₁ + γ ₂ R ₂ p ₂ applies. However, indexes 1 and 2 in the formula are the relationships between the first and second gases, respectively, and
Let p ₁ and p ₂ represent the weight percent of the first and second gases, respectively.

For ternary gas mixtures that additionally contain saturated steam in weight percent P ₃ , the relationship γR = γ ₁ R ₁ p ₁ + γ ₂ R ₂ p ₂ + γ ₃ R ₃ p ₃ holds true, and in a simple way can be reduced to the previous case. This is because the temperature value allows the determination of the amount of water present in the gas mixture, and thus on the other hand the concentration (%) values of the two other component gases can be determined from the temperature and the acoustic propagation velocity.

The accuracy of the data that can be provided by a gas analyzer according to the invention is closely and exclusively related to the accuracy of the measured temperature and the accuracy of the measured acoustic propagation velocity. These two test quantities can be measured in a reliable and unambiguous manner and, more importantly, without appreciable loss of time, with the aid of the equipment available in the state of the art.

In order to highlight the most important achievements of the gas analyzer according to the invention, special mention will be made of its advantages which will be described below. That is, the gas analyzer according to the invention operates at any desired pressure, and the test result is also independent of the actual pressure, and the device operates at any desired temperature, provided that the temperature value itself is known. In operation, the device gives a very fast and accurate readout of the concentration (%) to be measured, and if there is information about the concentration (%) of oxygen, the device also provides a second information (concentration (%) of carbon dioxide). %) can be obtained at the same time, and the device operates without any hassle even in the case of gases of insufficient purity, as is the case with the exhaust gas of internal combustion engines.

In the gas analyzer according to the present invention, the temperature testing device for checking the temperature is preferably a digital temperature detector.

In a preferred embodiment of the invention, the sound speed testing device for determining the speed of sound propagation in a gas mixture consists of an ultrasound transmitter and an ultrasound receiver. More preferably, the ultrasonic transmitter is comprised of a generator that generates an alternating voltage (current) at an ultrasonic frequency and an electro-acoustic transducer, and the ultrasonic receiver is comprised of an acoustic-electric transducer. consists of an acoustic-to-electrical transducer with a trailing amplifier, and the acoustic-to-electrical and electro-acoustic transducers are spaced apart or the phase comparator is connected to the generator. It is desirable to compare the phase of the signal emitted to generate an alternating current voltage (current) at ultrasonic frequencies with the phase of the signal received by the acousto-electrical transducer.

Advantageously, the calculation means for calculating the ratio V ² /T value or a value proportional thereto are constituted by a microprocessor, which microprocessor is provided with the output signal T of the temperature checking means and the output signal of the phase comparator. is input.

Next, a description will be given based on the attached figure, which is a block circuit diagram of one embodiment of the present invention.

A digital temperature probe 1 with a sensor 1a serves to check the temperature T of a gas mixture consisting of carbon dioxide and oxygen which is essentially saturated with water vapor. Such a gas mixture is used as the main gas for fueling a diesel engine with an exhaust gas recirculator dedicated to underwater operations through the supply line SC. However, details of this engine are not shown. The direction in which the gas mixture to be analyzed flows through the supply tube is indicated by an arrow. A generator 2, which generates a very high frequency alternating current voltage, for example at 40 kHz, is connected on the one hand to an electro-acoustic converter 3 and on the other hand to the input terminal of a phase comparator 4. The ultrasonic waves emitted by the electro-acoustic converter 3 are received by the acoustic-electric converter 5 and converted back into an alternating current voltage. This alternating voltage is supplied to the input terminal of an amplifier 6, the output of which is connected to the second input terminal of the phase comparator 4. The phase comparator 4 thus compares the phase of the signal emitted by the generator 2 with the phase of the signal received by the acousto-electrical converter 5. Transducers 3 and 5
Since it is separated from the phase comparator 4 by a certain distance,
The signal at the output of is directly proportional to the velocity V of the ultrasound waves passing across the gas mixture to be analyzed.

The output signal of the digital temperature probe 1 and the output signal of the phase comparator 4 constitute the main input data to the microprocessor 7. In this exemplary embodiment, the value of the quantity γR is the concentration of oxygen (%)
and temperature values. These pre-calculated values γRs are stored in the storage device 8. The microprocessor 7 calculates each ratio V ² /T, compares the value with γR of each concentration contained in the storage device 8, and calculates the oxygen concentration based on the relationship V ² /T=γR described above. A digital output signal is generated that directly indicates the concentration (%) (eg, γRc/γRs = %O ₂ ). The digital output signal of the microprocessor 7 constitutes input information to a supplemental oxygen regulator (not shown), which functions to determine the amount of oxygen gas to be added to the gas mixture in the fuel supply line. have The same digital output signal of the microprocessor 7 allows a direct reading of the oxygen concentration (%) and can be converted into a corresponding analog signal with the aid of a digital-to-analog converter 10 if necessary.

The calibration device 9 is capable of inputting additional calibration inputs (signals) to the microprocessor 7, which additional signals make it possible for the gas analyzer of the invention to
It is possible to tune the transducers 3 and 5 as a function of the actual constant time interval between them.

[Brief explanation of drawings]

The accompanying drawings schematically depict, in block circuit diagram form, one embodiment of the invention. The contents of the objects indicated by numerical symbols in the figure are as follows. 1... Digital temperature probe, 1a... Sensor, 2... Ultrasonic generator, 3... Electric-acoustic transducer, 4... Phase comparator, 5... Acoustic-electrical converter, 6... Increase Widget, 7...Microprocessor,
8...Storage device, built-in γRs, 9...Calibration device, 10...Digital-to-analog converter, 11
...engine, SC...supply pipe.

[Claims]

1. A tube that repeatedly bends the flow of liquid when it passes through the interior is rotatably supported around a predetermined axis, one end of a downwardly flexible liquid tube is coupled to the tube along the axis of rotation, and the A first intermediate portion of the liquid tube is extended to a second intermediate portion by bypassing a rotatable region of the tube so as not to touch the tube, and the first intermediate portion is extended around the axis of rotation. Rotate at rotation speed w ₁ , and
The intermediate portion is rotatable along the rotation axis on the side opposite to the coupled side and extends to a third intermediate portion, and the third intermediate portion is prevented from touching the first intermediate portion. The rotatable region of the first intermediate portion is detoured and extended to the other end, the third intermediate portion is rotated at a rotation speed w ₂ around the rotation axis, and the other end is rotated along the rotation axis. The tube is connected to a stationary system on the same side as the connected side, and while the tube is rotated at a rotation speed of 2 (w ₁ −w ₂ ), a liquid containing particles having different sedimentation coefficients or levitation coefficients is continuously applied to the tube. A liquid chromatographic separation method characterized in that the liquid is separated in the longitudinal direction of the tube with respect to its particle components within the tube. 2. At least two liquid tubes are used as the liquid tubes, one for supplying liquid from the stationary system to the tube and the other for discharging liquid from the stationary system to the stationary system. A method according to claim 1. 3 The liquid containing particle components is sugars, lipids, and amino acids.

Claims (1)

The value of the product of γ and R in (%) and the measured signal V,
Compare the value of V ² /T calculated based on T,
A gas analyzer comprising means for immediately generating a signal indicating gas concentration (%) based on the relationship V ² /T=γR. 2. The gas is mainly oxygen gas,
The storage device also stores a series of oxygen gas concentrations (%).
The signal generating means includes a storage device that stores in advance a sequence of discrete values of and respective values of γR for these discrete values of oxygen gas concentration (%),
The stored value of γR and the measured signal T,
Comparing the value of V ² /T calculated based on V,
Claim 1, wherein a signal indicating the gas concentration (%) is immediately generated based on V ² /T=γR.
The gas analyzer described in Section. 3. The gas analyzer according to claim 1, wherein the temperature testing means is a digital temperature detector. 4. The gas analyzer according to claim 1 or 2, wherein the sound velocity testing means comprises an ultrasonic transmitter. 5. The ultrasonic transmitter comprises a generator for generating an alternating current at an ultrathermal frequency, and the sensor is connected to an electro-acoustic transducer and an acoustic-electric transducer for generating the signal V. 5. The gas analyzer according to claim 4, wherein the converters are arranged at regular intervals in the supply pipe. 6. The sound velocity testing means includes the generator and the acoustic
a phase comparator connected to the electrical transducer, the phase comparator detecting the signal by comparing the phase of the generator signal with the phase of the signal received by the acousto-electrical transducer; The gas analyzer according to claim 5, which generates V. 7. The calculation means connected to both said testing means are microprocessors and include a calibration device, by means of which said gas analysis device is adjusted as a function of the actual constant time interval between said transducers. Claim 6: The microprocessor is provided with an additional calibration input signal capable of performing the tuning of the microprocessor.
The gas analyzer described in Section.