JPS6024421A - Flow-rate measuring device with temperature correction - Google Patents

Abstract

PURPOSE:To obtain accurate flow rates without errors in the flow rates due to the kinds of oils and temperatures, by the constitution, wherein signals from a flow-rate pulse generator and a temperature sensor are inputted in a control device, temperature correction is performed by the specific gravity, which is inputted previously, and the value of the flow rate is obtained. CONSTITUTION:Signals from a flowmeter 2 and a flow-rate pulse generator 4 and a signal from a temperature sensor 3 are inputted to a control device 5. A volume-conversion-factor table is stored in the control device 5 in advance. The specific gravity of oil, which is measured by a setting dial 6, is inputted to the control device. The converted volume is selected based on the signal from the sensor 3 and the specific gravity, which is inputted before. The signal from the flow-rate generator 4 and the flow rate, which undergoes temperature correction, are computed by the control device 5 and the integrated flow rate is displayed on a display device 9. Since the temperature correction is performed based on the specific gravity and the corrected value of the flow rate is obtained, errors are not yielded due the kind of oils and temperatures, and the accurate flow rates can be always obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature-compensated flow rate measuring device used, for example, in oil depots, oil refineries, and the like.

If the flow rate measuring device is of a volumetric type, errors occur because the volume of the fluid to be measured changes due to the epidemic. Conventional temperature-compensated flow rate measuring devices connect the output shaft of the flowmeter to an integrated flow rate display meter via a micro-variator, and adjust the speed of the micro-variator using a bellows that converts temperature changes in the fluid into mechanical displacement. By doing so, the temperature-corrected flow rate is integrated into the display set. By the way, changes in volume due to changes in concentration of crude oil and petroleum products are determined by JISK 22.
As specified in 49, not only temperature 1a changes, but also
Since it changes depending on the specific gravity of the fluid, it is not possible to accurately correct the fa degree with a conventional mechanical type, and as a result, it is not sufficient to accurately measure the flow rate.

Therefore, an object of the present invention is to provide a temperature-compensated flow rate measuring device that can accurately measure the flow according to the specific gravity and temperature of the fluid to be measured.

According to the present invention, a flow rate signal transmitter provided in a flow meter, a temperature measuring device for measuring the temperature of the fluid, a specific gravity setting device for setting the specific gravity of the fluid, and a volume conversion coefficient data of the fluid are stored, Then, a temperature correction coefficient is calculated using the 1113 measured by the temperature measuring device, the specific gravity set by the specific gravity setting device, and the volume conversion coefficient data, and the drought is corrected by the flow signal from the flow signal transmitter and the temperature correction coefficient. and a control device that calculates the flow rate value.

Therefore, according to the present invention, the temperature correction coefficient is calculated by the control device from the volume yA rod coefficient data stored in advance, the set specific gravity, and the measured drying point, and an accurate temperature-corrected flow rate is calculated using the control device. You can

The volumetric sieving coefficient table of JIS is extremely extensive, and the specific gravity and thirst mark are specified quite narrowly. Therefore, storing all of these numerical values requires a storage unit (ROM) of considerable capacity, and as a result, the control device inevitably becomes larger. Therefore, when implementing the present invention, it is preferable that the volume yA arithmetic table is not stored in its entirety, but is stored at certain numerical intervals, and intermediate values are calculated by proportional distribution. In other words, it is assumed that the value between two certain numerical values changes linearly. By doing so, the storage capacity of the control device can be reduced and substantially accurate values can be obtained.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of a flow rate measuring device implementing the present invention,
An oil storage tank, not shown, and Il!, also not shown. Oil supply pipes IA and I installed in the small 1-nozzle nozzle
A connecting pipe 1C equipped with a flow rate measuring device (to be described later) is flange-connected between B and 1C, and the connecting pipe 1C has a flow rate measuring device 12 for measuring the flow rate of oil flowing inside the pipe and measuring the temperature of the oil. A temperature sensor 3, which is a temperature measuring device, is provided. A flow rate pulse transmitter 4 which is a flow rate signal transmitter driven by the flow meter 2 is provided.
A flow rate signal from the controller 5 is input to the control device 5 as a pulse signal. Further, a temperature signal from the temperature sensor 3 is similarly input to the control device 5.

As described above, the control device 5 stores in advance the brightness v4 conversion coefficient table defined in JIS K 2249. Further, as will be described later, the specific gravity of the oil measured by the setting dial 6 is input into the control device M5. When the oil flows, a converted volume is selected from a volume conversion coefficient table based on the temperature signal from the temperature sensor 3 and the specific gravity input earlier, and a temperature correction coefficient is determined by the control device 5. Further, the flow rate temperature-corrected from the flow rate signal from the flow rate pulse transmitter 4 and the temperature correction coefficient is calculated by the control device 5, and the v4 calculated flow rate is displayed on the display meter 9, and is also transmitted to the batch counter 7, etc. (not shown).
: Sea urchins are turning. and flow rate pulse transmitter 4, control v
The i-station 5 and the display meter 9 are housed in an explosion-proof box 11.

FIG. 2 shows a preferred example of the series control device 5 implemented in the present invention, and in the figure, signals from the ratio 1 JiQ constant dial 6, the warm temperature heater 3, and the flow rate pulse transmitter 4 are sent to the input/output device @51. This input/output B position 51 is centrally controlled
Sends and receives signals to l tA 52.

This central control unit 52 receives signals from a timer 53, and also sends and receives signals to and from a storage device (ROM>54 and a temporary storage device (RAM) 55.This storage device 54 has a volume conversion coefficient It includes a data storage section 54a, a calculation formula storage section 54b for performing calculations in a manner described later, and a predetermined program 54C.
55 is a temporary storage section 55a that stores temperature correction coefficients, for example.
and a remaining amount storage section 55b that stores a fraction of the unit in a manner to be described later.

The JIS volume conversion coefficient table is 0°005o for specific gravity.
/cc, and thirst marks are determined in 0.5°C increments. However, as mentioned above, this requires a huge amount of storage, so when implementing the present invention, for example, as shown in the table below, the data storage section 54a has a specific gravity of 0.03.
It is sufficient to memorize the data every g/cc, and about the temperature every 5°C.

Volume conversion coefficient table Specification Weight 0/cc Measurement temperature °C... 0,78 0.81 0.84...
-251,03871,03531,03295484
441 10494441 15484441 20 49 44 41 25 48 44 41 75 , - - - In this table, the volume conversion coefficient is based on the temperature of -25°C, and the difference in the coefficient for every 5°C difference is stored, for example, specific gravity 0 This shows that the difference in volume conversion coefficient between the oil temperature of 5°C and the temperature of 10°C of .78 is 0.0049.

Next, embodiments of the present invention will be described mainly with reference to FIG.

FIG. 33(a) is a diagram showing a flowchart for calculating the temperature correction coefficient. First, the central control section 52 reads the specific gravity set on the specific gravity setting dial 6 (step S1). Assume that the set value is now 0.825. Next, the temperature of the temperature sensor 3 is read (step 82). Assume that the temperature is now 22°C. Next, the central control unit 52
A humidity correction coefficient, that is, a volume conversion coefficient is calculated based on the calculation formula stored in b (step 83).

The calculation is as follows.

(1) Specific gravity: 0.81.1 degrees 20'C17) Calculate the volume conversion coefficient (it iff with -25°C as the reference).

1.0353-Σ20/10000=0', 995 where Σ20 is the total value of the differences up to 20'C in the table.

(2) Calculate the volume conversion system with a specific gravity of 0.81 and a temperature of 25°C.

1.0353-Σ25/10000=0.9912 Here, Σ25 is the sum h1 of the differences up to 25°C in the table.

(3) Specific gravity 0.84, if 1 degree 20℃ (7) Calculate the volume conversion factor.

1.0329-Σ20/10000=0.9959 (4) Calculate the volume conversion coefficient for specific gravity 0.84 and temperature 25°C.

1.0329-Σ25/10000=0.9918 (5) Calculate the volume conversion coefficient of specific gravity 0.81.1 degrees and 22 degrees Celsius by proportional allocation.

0.9956- (0,9956-0,9912)X
(215)-0,9938 (6) Calculate the volume Fl coefficient for a specific gravity of 0.84.1 degrees and 22 degrees Celsius by proportional distribution.

0.9959- (0,9951-0,9918)X
(215)=0.9943 <7) From the values in (5) and (6) above, calculate the volume conversion coefficient for a specific gravity of 0.825 and a temperature of 22°C by proportional allocation.

0.9938+ ((0,9943-0,9938)x
(0,825-0,81))/ (0,84-0,8
1)=0.9941 Since this value 0.9941 is the temperature correction coefficient (volume conversion coefficient), it is stored in the temporary storage section 55a of the temporary storage device 55.
(step 84).

Although the temperature correction coefficient is calculated in this way, the temperature change of the fluid is not very drastic, and considering the time constant of the temperature sensor, it is sufficient if this flow is repeated every 2 to 3 seconds.

In addition, for the 4 points (5), (6), and (7) in Section 2, we first calculated II (22℃) using proportional distribution and then calculated the ratio ■, but after calculating the specific gravity, we calculated the temperature by 4 points. It's okay.

Next, referring to FIG. 3 (b), when a pulse signal is input from the flow rate pulse transmitter 4, the temperature-corrected flow rate is calculated using the above-mentioned temperature correction coefficient, and the integrated flow rate is displayed on the display meter 9. A specific example will be described below. That is, although the display it 9 is displayed by integer pulses, a fractional number occurs due to the above calculation. FIG. 3(b) is a preferable example of the rounding process.

A pulse (for example 0.
16) is input, step S! l).

This flow rate input is processed by a so-called interrupt signal, and the central processing unit 52 generates a temperature-corrected flow rate value (0,9941X0. 1=0.09941Q) (step Be), and the temporary storage device 55
Decorate the remaining fit value in the storage unit 55b (for example, if the remaining amount is 0.05432ff, 0.05432+0
．． 09941=0°15373ffl (step 87
．． ). Compare this decoration value with a unit amount (for example, O, IR) (step S8), and if the addition value is larger than the unit amount, output 1 pulse (0.1 g in flow rate) in step Ss.
), table filter 9 and batch counter 7 are accumulated for one pulse (0°1Q). Next, subtract the unit amount from the added value to get (0,15373-0,1=0.053
73N), store the remaining amount in the remaining amount storage section 55b (step S c ) a If the decoration value is less than the unit amount in step S8, the process returns without outputting a pulse to the display meter. Repeat this process below.

Therefore, in the control device, the needle is adjusted by a unit amount or less, and when the unit amount is exceeded, one pulse is output for the first time, thereby moving the display meter 9, etc.

Next, another embodiment will be explained with reference to FIG.

In the embodiment shown in Fig. 3, the set specific gravity is read every time, but in this embodiment, the set specific gravity is read only when the flow rate measurement starts O1I. When the power of the flow measuring device is turned on prior to starting the flow rate measurement in step B), the set specific gravity is read (step Sw>. Next, the central processing unit 52 calculates the specific gravity according to the same calculation as in the previous book). Each end f of the set specific gravity
Calculate the temperature correction coefficient for α Step S13
> , the mouth data is temporarily stored in the storage device 55. (step 514). In this way, the temperature correction coefficient for each temperature of the set specific gravity is previously calculated and stored. Next, as shown in FIG. 4(b), the temperature of the sea urchin temperature sensor 3 is read (step S+s>, and the temperature correction coefficient corresponding to the temperature stored in the temporary storage section 55a is calculated (step S16)). The temperature correction coefficient is stored in the temporary storage section 55a (step 517).When a flow rate pulse is input from the flow rate pulse transmitter 4 with a flow rate of 12, the flow rate calculation process is performed according to the flow shown in Fig. 3 (b). will be held.

As described above, according to the present invention, the dryness correction is performed based on the specific gravity and the corrected flow rate value is calculated.
No errors in flow rate due to oil type and temperature.
You can always set the correct flow rate.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the flow u1 measuring device implemented in the present invention,
FIG. 2 is a diagram showing a control circuit implemented in the present invention, FIGS. ) is a diagram showing a flowchart of an example of Haku. 2...Flow fttit, 4...Flow rate pulse transmitter 5
...Control device 6...Specific gravity setting dial 9...
Flow rate display resistance 52...Central control unit 54...Storage device 55...Temporary storage device 2nd TI! J Figure 3 Figure 3 Figure 4゜(A) Figure

Claims (1)

[Claims] A flow rate signal transmitter installed in the flow Mlil, a temperature measuring device that measures the temperature of the fluid, a specific gravity setting device that sets the specific gravity of the fluid, and a temperature measuring device that stores the fluid volume conversion coefficient data and measures it with the temperature measuring device. Calculate the temperature correction coefficient using the temperature set, the specific gravity set with the specific gravity setting device, and the volume conversion coefficient data,
A flow rate measuring device with temperature correction, further comprising: a control device that calculates a temperature-corrected flow rate value using a flow rate signal from a flow rate signal transmitter and a temperature correction coefficient.