CN204594514U - Laser micrometeor gauge - Google Patents

Abstract

The utility model is a laser micro-flow measuring instrument, which includes a pressure system, a measurement system and a data acquisition system. The pressure system includes a pressure pump, and the pressure pump is connected in parallel with a first intermediate container and a second intermediate container through a first pressure control pipeline; An intermediate container is connected to the measuring tube inside the pressure cabin through the first pipeline and the measured fluid pipeline, and the second intermediate container is connected to the bottom of the pressure cabin through the second pipeline; the measurement system includes the aforementioned measuring tube, one end of which is closed and the other end is open, The closed end is provided with a connection hole and is sealed and connected to the outlet of the measured fluid pipeline through the connection hole. An optical fiber collimator is provided on one side of the open end, and the first optical fiber and the second optical fiber are connected to the other side of the optical fiber collimator. The other ends of the optical fiber and the second optical fiber are connected to the laser ranging sensor; both the pressure pump and the laser ranging sensor are connected to the data acquisition system. The meter can solve the problem of low measurement accuracy of micro-flow fluid under high-pressure conditions, and realize measurement automation.

Description

Laser micro flow meter

technical field

The utility model relates to the measurement technology of fluid micro-flow, in particular to a laser micro-flow meter.

Background technique

In the simulation experiments related to the exploitation of tight oil and gas reservoirs, the experimental pressure is very high, generally tens or even nearly hundreds of MPa; in addition, because the pores are very small, the flow rate of the experimental fluid is ultra-low, generally nanoliters per minute (nL /min) level. For these experiments, especially the measurement of micro-flow in unsteady (such as pulse, vibration) seepage and oil displacement experiments, it is a technical difficulty that needs to be overcome urgently in tight oil and gas reservoir development experiments.

In this type of experiment, the commonly used flowmeters such as electromagnetic flowmeters, turbine flowmeters, mass flowmeters, etc. cannot be applied due to their large measuring range and low measurement accuracy. For fluid micro-flow measurement, the commonly used methods of flow measurement under high pressure in the laboratory are: metering pump method, capillary pressure measurement method and visual micro-flow method. Among them, the metering pump method has a large measurement error due to the influence of the compressibility of the liquid under high pressure and the leakage of the pump itself under high pressure; the capillary pressure measurement method has high requirements for the accuracy of the pressure sensor, which cannot be met by the existing pressure sensor. Measurement of high-pressure micro-flow; the visual micro-flow method provides a micro-flow measurement method with a pressure ≤ 30 MPa, which is suitable for microliter/minute (μL/min) level flow testing, and cannot accurately measure nanoliter/minute (nL/ min) level flow, and cannot meet the continuous metering of ultra-low flow (especially unsteady flow) under high-pressure experimental conditions.

Therefore, the inventor proposes a laser micro-flow meter to overcome the defects of the prior art by virtue of years of experience and practice in related industries.

Utility model content

The purpose of this utility model is to provide a laser micro-flow meter, which can solve the problem of low measurement accuracy of micro-flow fluid under high-pressure conditions in the prior art. Continuous real-time measurement of high-pressure micro-flow fluid under high-pressure conditions realizes the automation of micro-flow fluid measurement under high-pressure conditions.

The purpose of this utility model is achieved in this way, a laser micro-flow meter, including a pressure system, a measurement system and a data acquisition system, the pressure system includes a pressure pump, and one end of the pressure pump is connected to a first pressure control pipeline , the first intermediate container and the second intermediate container vertically arranged in parallel are connected on the first pressure control pipeline; a first valve is arranged between the first pressure control pipeline and the bottom inlet of the first intermediate container, so The outlet at the top of the first intermediate container is connected to a horizontally arranged fluid pipeline through a first pipeline, and a second valve is arranged on the first pipeline; There is a third valve, the outlet of the measured fluid pipeline seals through one side of a pressure chamber and is connected to the measurement system; a fourth valve is arranged between the first pressure control pipeline and the bottom inlet of the second intermediate container , the top outlet of the second intermediate container is connected through a second pipeline to the bottom of the pressure chamber, and a fifth valve is arranged on the second pipeline;

The measurement system includes a measurement tube horizontally arranged inside the pressure chamber, one end of the measurement tube is closed and the other end is open, the closed end of the measurement tube is provided with a connecting hole, and the outlet of the measured fluid pipeline is connected to the The holes are sealed and connected; one side of the opening end of the measuring tube is provided with a fiber collimator, and the other side of the fiber collimator is connected with a horizontally arranged first optical fiber and a second optical fiber at intervals, the first optical fiber and the second optical fiber The other end of the second optical fiber is respectively sealed through the other side of the pressure chamber and connected to a laser ranging sensor;

Both the pressure pump and the laser ranging sensor are connected to the data acquisition system.

In a preferred embodiment of the present utility model, the internal pressure value of the pressure chamber is greater than or equal to 0.1 MPa and less than or equal to 160 MPa.

In a preferred embodiment of the present utility model, the inner diameter of the measuring tube is greater than or equal to 1.5 millimeters and less than or equal to 3 millimeters.

In a preferred embodiment of the present utility model, a first piston is arranged inside the first intermediate container, and a second piston is arranged in the second intermediate container.

In a preferred embodiment of the present invention, mercury is filled in the first intermediate container above the first piston, and nitrogen is filled in the second intermediate container above the second piston.

In a preferred embodiment of the present utility model, the first pressure control pipeline, the first valve, the first intermediate container, the first pipeline, the second valve, the measured fluid pipeline, the third valve, the fourth valve, The second intermediate container, the second pipeline, the fifth valve and the pressure chamber are arranged inside a constant temperature box, and the first optical fiber and the second optical fiber pass through one side of the constant temperature box to connect with the laser distance measuring sensor.

In a preferred embodiment of the present utility model, the measurement accuracy of the thermostat is 0.1°C.

In a preferred embodiment of the present utility model, the length of the measuring tube is smaller than the distance between the third valve and the outlet of the first pipeline.

From the above, the laser micro-flow meter of the utility model has a simple structure and is easy to operate. Through the cooperation of the pressure chamber, the second intermediate container and the pressure pump, the pressure of the high-pressure fluid to be measured is balanced, and the pressure of the measurement environment is stable. Meet the requirements of stable and unsteady fluid measurement; make full use of the laser ranging sensor and optical fiber, reduce the measurement process error and improve the measurement accuracy; realize automatic control through the data acquisition system, reduce the influence of manual operation, and realize real-time measurement , to provide accurate data for the quantitative research of microscale flow experiments.

Description of drawings

The following drawings are only intended to illustrate and explain the utility model schematically, and do not limit the scope of the utility model. in:

Fig. 1 is a structural schematic diagram of the laser micro-flow meter of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation of the utility model is now described with reference to the accompanying drawings.

As shown in Figure 1, the laser micro-flow meter 100 provided by the utility model includes a pressure system 1, a measurement system 2 and a data acquisition system 3, and the pressure system 1 includes a pressure pump 11. In this embodiment, the pressure pump 11 For the high-precision pressure pump, RUSKA 7615 high-pressure pump (prior art) can be used, and its pressurization range is 0.1 MPa to 160 MPa (including the first and last values), and the pressure accuracy is 0.02% of the range; one end of the pressure pump 11 is connected with the first A pressure control pipeline 12, the first intermediate container 13 and the second intermediate container 14 arranged vertically are connected in parallel on the first pressure control pipeline 12, in this embodiment, the first intermediate container 13 is provided with a first piston 130 inside, The second intermediate container 14 is provided with a second piston 140, and the first intermediate container 13 is filled with mercury above the first piston 130, and the second intermediate container 14 is filled with nitrogen above the second piston 140; the first pressure control line 12 and the bottom inlet of the first intermediate container 13 is provided with a first valve 131, the top outlet of the first intermediate container 13 is connected to the measured fluid pipeline 4 arranged horizontally through a first pipeline 132, and a second valve 131 is arranged on the first pipeline 132. Valve 133; the inlet of the measured fluid pipeline 4 is connected to the detected high-pressure micro-flow experimental device (not included in the structure of the utility model, not shown in the figure), between the inlet of the measured fluid pipeline 4 and the outlet of the first pipeline 132 A third valve 41 is provided, and the outlet of the measured fluid pipeline 4 is sealed to pass through a pressure chamber 15 and connected to the measurement system 2; a fourth valve 141 is provided between the first pressure control pipeline 12 and the bottom inlet of the second intermediate container 14 , the top outlet of the second intermediate container 14 is connected through the second pipeline 142 to the bottom of the pressure chamber 15, and the second pipeline is provided with a fifth valve 143. In this embodiment, in order to meet the requirements of measuring high pressure conditions, the pressure inside the pressure chamber 15 The value is greater than or equal to 0.1 MPa and less than or equal to 160 MPa.

As shown in Figure 1, the measuring system 2 includes a measuring tube 21 horizontally arranged inside the pressure chamber 15. In this embodiment, the measuring tube 21 is a high-pressure tube, which can be a glass tube, a steel tube or other material tubes, In order to accurately measure the small flow of liquid, the inner diameter of the measuring tube 21 is generally set very small, but in order to meet the requirements of laser measurement, the inner diameter of the measuring tube 21 is greater than or equal to 1.5 mm and less than or equal to 3 mm. Backflow to the first pipeline 132, the length of the measuring tube 21 is less than the distance between the third valve 41 and the outlet of the first pipeline 132, so as to ensure that the measured fluid is always located at the third valve 41 and the outlet of the first pipeline 132 during the measurement process between, and will not enter the first pipeline 132 due to backflow; one end of the measuring tube 21 is closed and the other end is open, and the closed end of the measuring tube 21 is provided with a connecting hole 211, and the outlet of the measured fluid pipeline 4 is sealed and connected with the connecting hole 211; One side of the open end of the tube 21 is provided with a fiber collimator 22, and the other side of the fiber collimator 22 is connected with a first optical fiber 23 and a second optical fiber 24 arranged horizontally at intervals up and down, and the first optical fiber 23 and the second optical fiber 24 The other ends are respectively sealed and connected to a laser ranging sensor 25 through the other side of the pressure chamber 15 .

The pressure pump 11 and the laser distance measuring sensor 25 are all connected to the data acquisition system 3, the data acquisition system 3 is generally a computer, the pressure value of the pressure pump 11 and the measurement value of the laser distance measuring sensor 25 are all displayed in real time and recorded in the data acquisition system 3 Among them, the pressure value of the pressure pump 11 and the emission and reception of the laser ranging sensor 25 can be controlled in real time through the data acquisition system 3, realizing the automation of the measurement process.

Further, as shown in Figure 1, in order to ensure the stability of the experimental temperature under high pressure conditions, the first pressure control pipeline 12, the first valve 131, the first intermediate container 13, the first pipeline 132, the second valve 133, the tested The fluid pipeline 4, the third valve 41, the fourth valve 141, the second intermediate container 14, the second pipeline 142, the fifth valve 143 and the pressure chamber 15 are arranged inside an incubator 5, and the first optical fiber 23 and the second optical fiber 24 Pass through the incubator 5 side and be connected with the laser ranging sensor 25. In this embodiment, the precision of the thermostat 5 is 0.1°C, which ensures the precision of temperature measurement.

Before measurement by the laser micro-flow meter 100 provided by the utility model, the inlet of the measured fluid pipeline 4 is connected to the detected high-pressure micro-flow experimental device, and the pressure value of the pressure pump 11 is preset in the data acquisition system according to the experimental requirements. During measurement, at first close the second valve 133, the third valve 41, open the first valve 131, the fourth valve 141 and the fifth valve 143, open the pressure pump 11, through the pressure pump 11 to the first intermediate container 13 and the second intermediate container Fill or absorb water at the bottom of the container 14 to keep the pressure in the pressure chamber 15 reaching the preset pressure value. After the pressure stabilizes, close the fourth valve 141, open the second valve 133, and raise the pressure pump 11 a little (generally about 10 kPa). After a few seconds, the second valve 133 is closed to restore the pressure value before the pressure pump 11. At this time, a small amount of mercury enters the measured fluid pipeline 4. Then, turn on the laser ranging sensor 25, open the third valve 41, the measured fluid enters the measured fluid pipeline 4 and pushes mercury into the measuring tube 21, the measured fluid pushes the mercury to move in the measuring tube 21, and the laser ranging sensor 25 The emitted laser light passes through the first optical fiber 23 and the optical fiber collimator 22 to the mercury liquid surface, and the reflected light passes through the optical fiber collimator 22 and the second optical fiber 24 back to the laser ranging sensor 25, and records the measurement by the principle of laser ranging The displacement of the mercury in the tube 21 is transmitted back to the data acquisition system 3, and the distance and time relationship between the laser ranging sensor 25 and the mercury interface in the measuring tube 21 is measured, and the instantaneous flow rate can be calculated. After the analysis result is obtained, close the first valve 131 and the third valve 41, open the fourth valve 141, raise the pressure of the pressure pump 11 a little (generally about 10 kPa), and the internal pressure of the pressure chamber 15 is raised to push the mercury out of the measuring tube 21 And flow back into the first intermediate container 13, then the above operation can be repeated for the next measurement.

From the above, the laser micro-flow meter of the utility model has a simple structure and is easy to operate. Through the cooperation of the pressure chamber, the second intermediate container and the pressure pump, the pressure of the high-pressure fluid to be measured is balanced, and the pressure of the measurement environment is stable. Meet the requirements of stable and unsteady fluid measurement; make full use of the laser ranging sensor and optical fiber, reduce the measurement process error and improve the measurement accuracy; realize automatic control through the data acquisition system, reduce the influence of manual operation, and realize real-time measurement , to provide accurate data for the quantitative research of microscale flow experiments.

The above descriptions are only illustrative specific implementations of the present utility model, and are not intended to limit the scope of the present utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the protection scope of the present invention.

Claims (8)

1. a laser micrometeor gauge, it is characterized in that: described laser micrometeor gauge comprises pressure system, measuring system and data acquisition system (DAS), described pressure system comprises a forcing pump, described forcing pump one end is connected with the first control pressure line, described first control pressure line is parallel with the first intermediate receptacle and the second intermediate receptacle that vertically arrange; Be provided with the first valve between described first control pressure line and described first intermediate receptacle bottom inlet, described first intermediate receptacle top exit is connected to horizontally disposed detected fluid pipeline by the first pipeline, and described first pipeline is provided with the second valve; Be provided with the 3rd valve between described detected fluid line inlet and described first pipeline outlet, described detected fluid pipeline outlet hermetically passing one pressure chamber side is connected with described measuring system; Be provided with the 4th valve between described first control pressure line and described second intermediate receptacle bottom inlet, described second intermediate receptacle top exit is connected with through bottom described pressure chamber by the second pipeline, described second pipeline is provided with the 5th valve;

Described measuring system comprises the measuring tube that is horizontally placed on described pressure chamber inside, and one end open is closed in described measuring tube one end, and the blind end of described measuring tube is provided with connecting hole, and described detected fluid pipeline outlet and described connecting hole are tightly connected; The openend side of described measuring tube is provided with optical fiber collimator, described optical fiber collimator opposite side is between the upper and lower every being connected with horizontally disposed first optical fiber and the second optical fiber, and the other end of described first optical fiber and described second optical fiber respectively pressure chamber opposite side described in hermetically passing is connected to a laser range sensor;

Described forcing pump and described laser range sensor are all connected to described data acquisition system (DAS).

2. laser micrometeor gauge as claimed in claim 1, is characterized in that: described pressure chamber internal pressure value is more than or equal to 0.1 MPa and is less than or equal to 160 MPas.

3. laser micrometeor gauge as claimed in claim 1, is characterized in that: described measuring tube internal diameter is more than or equal to 1.5 millimeters and is less than or equal to 3 millimeters.

4. laser micrometeor gauge as claimed in claim 1, is characterized in that: described first intermediate receptacle inside is provided with first piston, is provided with the second piston in described second intermediate receptacle.

5. laser micrometeor gauge as claimed in claim 4, it is characterized in that: described first intermediate receptacle inside is positioned at above described first piston is equipped with mercury, described second intermediate receptacle inside is positioned at above described second piston and is filled with nitrogen.

6. laser micrometeor gauge as claimed in claim 1, it is characterized in that: it is inner that described first control pressure line, the first valve, the first intermediate receptacle, the first pipeline, the second valve, detected fluid pipeline, the 3rd valve, the 4th valve, the second intermediate receptacle, the second pipeline, the 5th valve and pressure chamber are arranged at a constant temperature oven, described first optical fiber is connected with described laser range sensor through described constant temperature oven side with described second optical fiber.

7. laser micrometeor gauge as claimed in claim 6, is characterized in that: the measuring accuracy of described constant temperature oven is 0.1 DEG C.

8. laser micrometeor gauge as claimed in claim 1, is characterized in that: the length of described measuring tube is less than the distance between described 3rd valve and described first pipeline outlet.