JPS63212852A - Optical interference type gas calorific value measuring apparatus - Google Patents

Abstract

PURPOSE:To reduce the consumption of standard gas by keeping the concn. of the standard gas in a standard cell constant over a long time, by a method wherein the gas discharge port of a standard gas cell is allowed to communicate with the fuel gas discharge pipeline of a measuring gas cell to discharge fuel gas. CONSTITUTION:When gas having a known calorific value as near as possible to the calorific value of the fuel gas flowing through a gas supply line L is selected to operate an apparatus, the fuel gas flowing through the gas supply line L flows in the first cell 1 while the flow rate is adjusted to a definite value by a flow control mechanism 2. The standard gas received in a cylinder 8 flows in the second cell 4 while the flow rate thereof is controlled to a definite value by a flow rate control mechanism 5 and issues to a discharge port 20 after a definite time while discharges the gas remaining in the cell 4. When the supply of the standard gas from the cylinder 8 is stopped in this state, the standard gas received in the second cell 4 communicates with the discharge port 20 through the fuel gas and, therefore, the initial concn. can be kept in the cell 4 over a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a standard gas supply mechanism in a gas calorific value meter using optical interference.

(Prior art) Fuel gas production process (in this case, two optical cells A whose exhaust ports a and b are open to the atmosphere as shown in FIG.
While flowing the gas to be measured and the standard gas into B,
Light from the same light source C is transmitted through both cells to cause interference, and the heat generation of the fuel gas is measured based on the degree of interference. Note that the symbol F in the figure indicates a detector that measures the degree of interference.

By the way, standard gas is normally supplied by a pump D, so in order to save on consumption as much as possible, it is released through a resistance tube G, but the cylinder still needs to be replaced several times a year. This has the disadvantage that maintenance is time-consuming.

(Objectives) The present invention was made in view of these problems, and its objects are to provide an interferometric gas heat measuring device M that can dramatically reduce the consumption of 1ml of standard gas. It is to be.

(Summary of the Invention) In other words, the present invention is characterized in that dissipation due to diffusion of the standard gas is suppressed by communicating the outlet of the gas cell to be measured and the outlet of the standard gas cell to a common outlet. It is in.

(Example) The details of the present invention will be described below based on illustrated examples.

FIG. 1 shows an embodiment of the present invention, and reference numeral 1 in the figure indicates a first cell into which the gas whose calorific value is to be measured flows, and the gas inlet port formed on the side thereof is a is connected to a gas supply line L via a gas flow rate adjustment mechanism 2, and the other end is connected to a discharge port 20 via a vibrator 3.

Reference numeral 4 denotes a second cell into which standard gas flows, and a gas inlet 4a formed on the side is connected to a standard gas cylinder 8 via a gas flow rate adjustment mechanism 5 and a solenoid valve 6 that is intermittently opened and closed by a timer 15. The gas discharge port 4b is connected to the discharge port 20, which is connected to the gas discharge vibrator 3 of the first cell 1 via a resistance tube 9 formed by winding or bending a carrier and a rary tube into a coil shape. are commonly connected. The light from the light source 11 is divided into two optical paths and enters the cells 1.4 using a parallel plane glass plate, and the light emitted from the first and second cells 1.4 is transmitted through a parallel plane glass plate 12. An interference measurement meter is constructed by guiding the light beams along the same optical path to cause interference and then inputting the light beams into the photoelectric detector 13. The signal from this detector] 3 is input to a calorific value conversion circuit 14 and is converted into a calorific value based on the refractive index.

In this embodiment, the gas supply lamp LV has a heat generation value as close as possible to the calorific value of the flowing fuel gas, has a known calorific value, that is, as close as possible to the fuel gas, and has a refractive index. When a known standard gas is selected and the device is operated, the fuel gas flowing through the gas supply will be
The flow rate is adjusted to a constant level by the flow rate adjustment mechanism 2 and flows into the first cell 1 .

On the other hand, the standard gas contained in the cylinder 8 flows into the second cell 4 at a constant flow rate by the flow rate adjustment mechanism 5 through the solenoid valve 6 which is opened by the drive signal from the timer 15, and flows into the second cell 4. After a certain period of time, the gas remaining in the gas is discharged from the discharge port 20 through the resistance pipe 9 from the discharge port 4b.
Go out. At this stage, when the solenoid valve 6 is closed by a signal from the timer 15 and the supply of standard gas from the cylinder 8 is cut off, the standard gas contained in the second cell 4 has approximately the same composition as this. Because it communicates with the outlet 20 through the fuel gas that it has, the diffusion rate is extremely low compared to when it comes into contact with the atmosphere, and the initial concentration can be maintained within the cell 4 for a long time. Become. In this state, the light source 11
Since the light incident from the standard gas and the fuel gas interfere in proportion to the difference in Φ, the degree of this interference indicates the calorific value of the fuel gas. When the fuel gas supply pressure changes during this measurement process, the pressure of the standard gas in the second cell 4, which is connected to the first cell 1 through the resistance tube 9, changes accordingly. The accompanying errors will be kept as small as possible.

In this way, when the concentration of the standard gas in the second cell 4 has decreased, the solenoid valve 6 is opened and the standard gas is supplied from the cylinder 8, and the gas in the second cell 4 has been replaced. Close the solenoid valve 6.

Thereafter, when the standard gas concentration in the second cell has decreased in this manner, the electromagnetic valve 6 is opened and measurements are continuously performed while supplying the standard gas.

Note that in this embodiment, the gas discharged from the cell 1.4 is discharged into the atmosphere, but the same effect cannot be achieved even if the gas is returned to the fuel gas supply line. it is obvious.

[Example] A gear and a rally with a diameter of 2 mm and a length of 2 m are used as the resistance tube 9.
Using a tube, the gas outlet 4b of the M2 cell 4 is connected to the gas outlet 1b of the first cell 1, and the standard gas has a calorific value of 7000 kcal/m3, and the fuel gas has a calorific value of 8000 kcal/m3. When measurements were carried out with a constant m3 gas and a standard gas injected once, constant measured values could be obtained for about 40 minutes, as shown by solid line A in FIG.

For comparison, measurements were performed using the same gas as above with the gas outlet of the second cell opened directly to the atmosphere (Figure 3), and as shown by dotted line B, from the start of the measurement The measured value fluctuated in about 4 minutes.

From this, by commonly connecting the gas discharge ports of each cell, the concentration of the standard gas in the cell can be maintained constant for about 10 times longer, and the consumption 11 can be dramatically reduced to 1/]0. found.

(Effects) As described above, according to the present invention, the gas discharge port of the standard gas cell is communicated with the fuel gas discharge pipe of the measurement gas cell, and then the standard gas is discharged. is discharged to the outlet via similar fuel gas, the diffusion rate becomes small, and the concentration of the standard gas in the standard cell can be maintained constant over a long period of time. Gas consumption can be dramatically reduced.

In addition, since the standard gas cell and the fuel gas cell are in communication, fluctuations in fuel gas pressure within the cell can be offset by acting on the standard gas pressure, making it possible to measure calorific value with high accuracy. can.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an apparatus showing an embodiment of the present invention, Fig. 2 is a diagram showing measurement results showing the operation of the snow making machine, and Fig.
The figure is a configuration diagram showing an example of a conventional optical interference type gas calorimetry device. ]...Measurement cell 1a...Fuel gas inlet 1b...Fuel gas outlet 3...Fuel gas exhaust vibrator 4...Standard cell 4a...Standard gas inlet 4b...Standard gas discharge port 8...Standard gas cylinder 9...Resistance tube 2o...Discharge port

Claims (1)

[Claims] The first cell and the second cell, to which the fuel gas and the standard gas are respectively supplied, are irradiated with light from the same light source to measure the calorific value of the fuel gas by optical interference. An optical interference type gas calorific value measuring device in which a gas discharge port of one cell and a gas discharge port of a second cell are communicated with each other and connected to the discharge port.