JPH041526A - Temperature detecting mechanism of orifice flowmeter - Google Patents

Abstract

PURPOSE:To facilitate installation construction by installing a temperature sensor for fluid temperature detection in the connection path of a ring which supports an orifice plate. CONSTITUTION:In the connection path 4 of the ring 3 which supports the orifice plate 1, the temperature sensors 6 for fluid temperature detection are installed. Consequently, the ring 3 is clamped by a flange part 11 and installed in a fluid transporting pipe 12, and conductors 8 from connecting pipes 5 and temperature sensors 6 corresponding to the upstream side and downstream side of the orifice 2 are connected to a flow rate deriving means 7 to complete the installation, thereby facilitating the installation construction. Further, the temperature sensors 6 are installed corresponding to the upstream side and downstream side of the orifice 2 and the means value of their measured values is calculated to accurately measure the temperature of fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a temperature detection mechanism in a throttle flow meter.

(Prior Art) A restrictor flowmeter is a flowmeter that measures the flow rate of fluid flowing in a fluid transfer pipe, but such a flowmeter can measure the true flow rate even when the temperature of the fluid changes. In order to do this, a temperature sensor is provided in the fluid transfer pipe to measure the temperature of the fluid.

Conventionally, as shown in Fig. 3, the temperature sensor a is installed at a 40 mm diameter point on the upstream side from the installation location of the orifice C in the fluid transfer pipe in order to avoid disturbance to the flow rate measurement.
It is inserted and installed more than twice as far away.

(Problem to be Solved by the Invention) In this way, conventionally, the temperature sensor a is installed at a location away from the installation location of the orifice C, so the piping design is such that a straight pipe section d is installed at a sufficient distance between them. In addition, installation of the temperature sensor a and instrumentation-related work and instruments are required to combine the differential pressure detection part by the orifice C and the temperature detection part to configure a temperature correction mechanism,
There is a problem with high costs. In the figure, the symbol e is a differential pressure transmitting section, f is a temperature transmitting section, g is a correction calculation section, and h is a flow rate indicator.

The present invention aims to solve the above problems.

(Means for Solving Section 1) In order to solve the above problems, the temperature detection mechanism in the throttle flowmeter of the present invention supports an orifice plate and connects a pressure channel for measuring the differential pressure of the orifice. The provided ring is installed in a fluid transfer pipe, and a temperature sensor for detecting fluid temperature is installed in the pressure guiding path of the ring.

In the above configuration, the temperature sensors can be installed at multiple locations in the pressure guide path of the ring. In addition, the ring
The structure may be such that the orifice plate is held and supported, or the structure may be formed integrally with the orifice plate and supported.

(Function) In the above configuration, when the ring is installed in the fluid transfer pipe, the differential pressure of the orifice can be detected by the differential pressure detection means via the pressure guide path, and the temperature of the fluid can be detected by the pressure difference detecting means through the pressure guide path. It can be detected by an installed temperature sensor, and the true flow rate can be measured by performing temperature correction from the thus measured differential pressure and fluid temperature.

Since the temperature sensor is installed in the pressure path, it does not cause any disturbance to the flow rate measurement. Further, since the temperature sensor can be installed at the same time as the orifice is installed using the ring, the construction is easy, and the fluid transfer pipe does not require a straight pipe section of sufficient length as in the conventional case.

(Example) Next, an example of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, the reference numeral 1 is an orifice plate forming the orifice 2 of the throttle flowmeter, and the reference numeral 3 is an orifice plate that supports the orifice plate 1 and is provided with a pressure guide path 4 for measuring the differential pressure of the orifice 2. It is a ring. The pressure guide path 4 for differential pressure measurement has an annular configuration along the ring 3, and the ring 3 is provided with a pressure guide pipe 5 communicating with the pressure guide path 4. Although the ring 3 shown in this figure is constructed to sandwich and support the orifice plate 1, it may also be constructed integrally with the orifice plate 1 and supported (not shown). In this configuration, a temperature sensor 6 such as a semiconductor thermistor is installed in the pressure guide path 4 of the ring 3. The temperature sensors 6 are installed at a plurality of locations in the annular pressure guide path 4, for example, at three locations at each position rotated by 120'. Incidentally, the conductive wire 8 connecting these temperature sensors 6 and the flow rate deriving means 7 described later is airtightly connected by an appropriate mechanism.
The pressure is led out from the pressure path 4 to the outside of the ring 3.

Reference numeral 7 denotes a flow rate deriving means, and this flow rate deriving means 7 includes a differential pressure measuring section 9 that connects the impulse pipes 5 corresponding to the upstream and downstream sides of the orifice 2 to measure the differential pressure, and It is composed of a calculation section 10 which connects temperature sensors 6 corresponding to the upstream and downstream sides of the orifice 2, respectively, and derives the flow rate based on the temperature measured by the temperature sensors 6 and the differential pressure. The flow rate deriving means 7 may be configured to output only a flow rate signal, or may be configured to output a temperature or differential pressure signal as required. Furthermore, the calculation unit 10 can accurately measure the temperature of the fluid by averaging the temperatures detected by the plurality of temperature sensors 6.

In the above-described mechanism of the present invention, the ring 3 supporting the orifice plate 1 is sandwiched between the flange portions 11 and installed in the fluid transfer pipe 12, and the guides corresponding to the upstream and downstream sides of the orifice 2 are installed. The installation is completed by connecting the pressure pipe 5 and the conductor 8 from the temperature sensor 6 to the flow rate deriving means 7.

Note that the flow rate deriving means 7, the pressure guiding pipe 5, and the conducting wire 8 may be connected in advance. In this way, in the present invention, the orifice 2 and the temperature sensor 6 can be installed in an integrated manner, so the installation work is simple and the cost is low.

In the above configuration, the differential pressure between the upstream side and the downstream side of the orifice 2 can be detected by the differential pressure detection unit 9 from the pressure guiding path 4 via the guiding pressure f5, and the temperature of the fluid can be detected by the pressure guiding path 4. The true flow rate can be derived by detecting the temperature with a temperature sensor 6 installed inside and performing temperature correction in the calculating section 10 of the flow rate deriving means 7 from this temperature and the differential pressure. As mentioned above.

Since the temperature sensor 6 is installed in the pressure guiding path 4, it does not cause any disturbance to the flow rate measurement. A plurality of temperature sensors 6 are installed corresponding to the upstream and downstream sides of the orifice 2, and by averaging these measured values, the temperature of the fluid can be accurately measured. accuracy can be improved.

(Effects of the Invention) As described above, the present invention provides a temperature sensor for measuring the temperature of a fluid, which has conventionally been installed at a long distance upstream from the orifice installation point, through the pressure guide path of the ring that supports the orifice plate. Since it is installed inside, it does not cause any disturbance to the flow rate measurement as in the past, and the temperature sensor and orifice can be installed at the same time, which simplifies construction and reduces costs. The pipe does not require a sufficiently long straight pipe section as in the conventional case, and therefore has the advantage of having a high degree of freedom in piping design.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view showing the overall configuration of an embodiment of the present invention, FIG. 2 is an explanatory sectional view taken along the line X--X of FIG. 1, and FIG. 3 is an explanatory view of a conventional example. Symbol 1... Orifice plate, 2... Orifice, 3... Ring, 4... Pressure path for differential pressure measurement, 5...
- Impulse pipe, 6... Temperature sensor, 7... Flow rate deriving means, 8 river conductor, 9... Differential pressure measuring section, 10... Calculating section,
11...Flange portion, 12...Fluid transfer pipe. Figure 1 Figure 2 Figure ¥3

Claims (4)

[Claims] (1) A ring supporting the orifice plate and provided with a pressure path for measuring the differential pressure of the orifice was installed in the fluid transfer pipe, and a temperature sensor for detecting fluid temperature was installed in the pressure path of the ring. Temperature detection mechanism in a throttle flowmeter characterized by (2) The temperature sensor according to claim 1 is a temperature detection mechanism in a throttle flowmeter, characterized in that the temperature sensor is installed at multiple locations in a pressure guide path of a ring. (3) A temperature detection mechanism in a throttle flowmeter, characterized in that the ring of claim 1 is configured to clamp an orifice plate. (4) A temperature detection mechanism in a throttle flowmeter, characterized in that the ring of claim 1 is constructed integrally with an orifice plate.