Flow measuring device and mass flow controller

Abstract

The utility model belongs to the technical field of flow measurement, and discloses a flow measurement device and a mass flow controller. The flow measuring device comprises a main pipeline used for conveying fluid; the flow sensor is used for measuring the flow of the fluid and comprises an inlet pipe section and an outlet pipe section which are connected with the main pipeline, and the inlet pipe section and the outlet pipe section are sequentially arranged on the main pipeline in the flowing direction of the fluid; the laminar flow element is arranged in the main pipeline, and the laminar flow element is arranged between the inlet pipe section and the outlet pipe section; the flow resistance adjusting mechanism is arranged in the main pipeline and located between the inlet pipe section and the laminar flow element; the control module is used for controlling the flow resistance adjusting mechanism to adjust the flow resistance of the main pipeline between the inlet pipe section and the laminar flow element; the technical problems that in the prior art, due to the fact that a fixed split ratio is adopted, the measuring precision and the response speed of a flow sensor are affected, and the measuring range of a mass flow controller is fixed can be solved.

Claims

1. A flow measurement device, characterized in that: include: Main pipeline, used to transport fluid; A flow sensor, used to measure the flow rate of the fluid, the flow sensor comprising an inlet pipe section and an outlet pipe section connected to the main pipe, the inlet pipe section and the outlet pipe section are sequentially arranged on the main pipe along the flow direction of the fluid; A laminar flow element is disposed in the main pipeline, wherein the laminar flow element is disposed between the inlet pipe section and the outlet pipe section; A flow resistance adjustment mechanism is disposed in the main pipeline and between the inlet pipe section and the laminar flow element; The control module is used to control the flow resistance adjustment mechanism to adjust the flow resistance of the main pipeline between the inlet pipe section and the laminar flow element.

2. The flow measurement device according to claim 1, characterized in that: The flow sensor is used to transmit measured flow information to the control module; A lower flow limit and an upper flow limit are preset in the control module. The control module is used to control the flow resistance regulating mechanism to increase the flow resistance of the main pipeline when the fluid flow rate is lower than the lower flow limit, and to control the flow resistance regulating mechanism to reduce the flow resistance of the main pipeline when the fluid flow rate is higher than the upper flow limit.

3. The flow measurement device according to claim 1, characterized in that: The flow resistance adjustment mechanism includes a piezoelectric ceramic component, which includes at least two stacked piezoelectric ceramic sheets. The stacking direction of the piezoelectric ceramic sheets is arranged at an angle to the fluid flow direction in the main pipeline. The control module is used to control the volume of the piezoelectric ceramic sheets to increase or decrease, so as to control the flow resistance of the main pipeline to increase or decrease.

4. The flow measurement device according to claim 3, characterized in that: The flow resistance adjustment mechanism also includes a support member, which is connected to the main pipeline. A through hole is provided in the support member, and the piezoelectric ceramic component is provided in the through hole. One end of the piezoelectric ceramic component along the stacking direction is connected to the hole wall of the through hole.

5. The flow measurement device according to claim 4, characterized in that: The through hole is a rectangular hole extending along the flow direction of the fluid in the main pipeline, and the piezoelectric ceramic component is connected to any inner surface of the through hole.

6. The flow measurement device according to claim 4, characterized in that: The laminar flow element is spaced apart from the support member.

7. The flow measurement device according to claim 6, characterized in that: The flow measurement device further comprises a first sleeve disposed in the main pipe, the first sleeve extending along a fluid flow direction in the main pipe, and the first sleeve being disposed between the support member and the laminar flow element to separate the support member from the laminar flow element.

8. The flow measurement device according to claim 7, characterized in that: The flow measurement device further comprises a second sleeve arranged in the main pipe, wherein the second sleeve is arranged on a side of the support member away from the laminar flow element to limit the position of the support member along the fluid flow direction in the main pipe.

9. The flow measurement device according to claim 4, characterized in that: The flow resistance adjustment mechanism also includes a telescopic tube, the piezoelectric ceramic component is arranged in the telescopic tube, the telescopic tube extends along the stacking direction of the piezoelectric ceramic component, one end of the telescopic tube along the length direction is sealed and connected to the hole wall of the through hole, and the other end of the telescopic tube is sealed and connected to one end of the piezoelectric ceramic component away from the hole wall of the through hole.

10. A mass flow controller, characterized in that: comprising a flow measurement device as claimed in any one of claims 1 to 9; The mass flow controller also includes a valve and a control device, wherein the valve is connected to the main pipeline, and the control device is used to adjust the opening of the valve according to the flow information measured by the flow sensor to adjust the flow of the fluid in the main pipeline.

Images