JPH0458114A - Intermittently driven integration type flowmeter - Google Patents

Abstract

PURPOSE:To decide the safety while monitoring a flow rate in time unit by driving a flow sensor intermittently, operating the flow rate according to the signal outputted by the sensor, and generating a unit flow rate signal which is integrated by a counter. CONSTITUTION:The flow sensor 1 is driven once in every five seconds by an intermittent driving controller 2 through a driving circuit 3. The output of the sensor 1 is counted by the counter 4 and the quantity of a flow in five minutes is calculated by an integral amount arithmetic circuit 5. An integral quantity (v) in every intermittent operation which is operated by the integral quantity arithmetic circuit 5 is divided by a preset division number (n), an integral quantity v/n divided at time intervals T/n obtained by dividing an intermediate operation time interval T by (n) is outputted from an integral quantity converting circuit 6 to the counter 7 and further outputted to a unit flow rate signal generating circuit 8, so that its signal is outputted to a monitor circuit side like an abnormality decision circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an intermittent drive integrating flow meter that measures and integrates the flow rate while intermittently driving a flow rate measurement sensor.

[Conventional technology] Thermal flow rate sensor (
In the case of a flow sensor (hereinafter referred to as a "flow sensor"), the flow rate is measured by driving it at fixed time intervals, taking into consideration the economic efficiency of electric power, etc. (Japanese Patent Application Laid-Open No. 1-308921
).

[Problems with the Prior Art] However, in this known example, the drive is performed at predetermined time intervals, that is, every 5 seconds, and the value accumulated over the 5 seconds is calculated from the flow velocity measurement values every 5 seconds.

Therefore, for example, when there is a flow rate of 10011/h, 5
The volume flowing per second is 0.1389! Since l, 5
The value 0.138911 is accumulated every second. Therefore, if a signal is output every time ill adjustment is made from this integrated value, the first signal will be 4 times after the start of measurement.
The signal is output after 0 seconds, the second signal is output after 75 seconds, and the third signal is output after 110 seconds. For this reason, even if a constant flow rate is flowing, signals for each Ill are not output at equal time intervals. Therefore, this signal is used to determine the flow rate (
If you attempt to carry out monitoring, etc., it will be determined that there has been a change in flow rate even if the flow rate is constant.

[Means for Solving the Problems] The present invention is proposed in view of the above points, and its configuration is as follows.

A flow rate measurement sensor that measures the flow rate of the fluid to be measured.

an intermittent drive control circuit that drives the sensor intermittently; an integrated amount calculation circuit that calculates and integrates the flow rate based on a signal output from the sensor; and an intermittent operation 1 calculated by the integrated amount calculation circuit. Divide the accumulated amount for each operation into a preset number of divisions (V8), intermittent operation time interval T
an integration amount conversion circuit that outputs the divided integration amount (v/n) at every time interval (Tb) obtained by dividing the integration amount into n; an integration counter that measures the aX amount output from the integration amount conversion circuit; An intermittent drive integrating flowmeter that has a unit flow rate signal generation circuit that generates a unit flow rate signal integrated by a counter.

[Operation] The intermittent drive control circuit sends an intermittent drive signal to the sensor. As a result, the sensor is driven intermittently and outputs intermittent flow signals.

The signal output in this way is input into the integrated amount calculation circuit, where the flow rate is integrated, and this integrated value is outputted to the integrated amount conversion circuit.

The integrated amount conversion circuit divides the integrated amount for each intermittent operation into a predetermined number of divisions (V8), and divides the intermittent operation time interval T into n divisions (T/n). The cumulative amount (v/'n) thus obtained is output to the cumulative counter.

The integration counter counts the integrated amount, outputs the counted value to a unit flow rate signal generation circuit, and outputs it from the unit flow rate signal generation circuit to a monitoring circuit such as an abnormality determination circuit.

[Example] Fig. 1 shows the configuration of an integrating flow meter that drives a flow sensor l intermittently. Here, the flow sensor 1 is driven by the intermittent drive control circuit 2 via the drive circuit 3 once every 5 seconds. The output from the flow sensor 1 is counted by a counter 4, and the volume flowing in 5 seconds is calculated by an integrated amount calculation circuit 5. For example, at a flow rate of 100 m/h, 0.1 per 5 seconds
389 Deaf volume flows. The integrated amount conversion circuit 6 is this 0
．． 1389! For example, divide the value of l by 100, and divide it into 0.00138 for every 0.05 seconds of "/+oo" with an intermittent drive interval of 5 seconds.
Sends the cumulative amount of 9Q to the cumulative quantity. The integration counter 7 adds the received value to the previous integration value. The unit flow rate signal generation circuit 8 generates a unit flow rate signal when the integrated value reaches a unit flow rate (for example, IQ). 9 in the diagram
is a timer, and lO is an LCD display section.

FIG. 2 shows a timing chart. As is clear from this figure, in the conventional example, the unit flow rate signal is output at a different time from when it actually reaches 1+1, or according to the present invention, it is output at the time when it reaches l(.

[Effects of the present invention] As described above, the present invention outputs a unit flow rate signal at the correct time even in an intermittent drive type integrating flowmeter, so its safety can be determined while monitoring the flow rate on an hourly basis. The present invention can be used effectively in gas accident prevention devices (Japanese Patent Publication No. 61-59423).

[Brief explanation of drawings]

FIG. 1 is an embodiment of the present invention, and FIG. 2 is a time chart showing the output status of flow rate signals according to the present invention and the conventional intermittent drive method. l...Sensor 2...Intermittent drive control circuit 3...Drive circuit 4...Counter integration amount calculation circuit Integration amount conversion circuit Integration counter unit flow rate signal generation circuit Timer LCD display section

Claims (1)

[Scope of Claims] A flow rate measurement sensor that measures the flow rate of a fluid to be measured; an intermittent drive control circuit that drives the sensor intermittently; and a flow rate measurement sensor that calculates and integrates the flow rate based on a signal output from the sensor. The integrated amount calculating circuit calculates the integrated amount, and the integrated amount v for each intermittent operation calculated by the integrated amount calculating circuit is divided into a preset number of divisions n (v/n), and the intermittent operation time interval T is divided into n. an integration amount conversion circuit that outputs the divided integration amount (v/n) at each time interval (T/n); an integration counter that measures the integration amount output from the integration amount conversion circuit; An intermittent drive integrating flowmeter that has a unit flow rate signal generation circuit that generates an integrated unit flow rate signal;