Principle and design of Bitobar integrated mass flowmeter

Contents

The invention relates to a Bitopard mass flowmeter for measuring the mass flow of a fluid in a pipeline, and in particular to a Bitopard integrated mass flowmeter for measuring the mass flow of a mixed fluid in a pipeline.

Background of the Invention

The Bitobar mass flowmeter currently used to measure the mass flow of fluid in a pipeline mainly includes a Bitobar flow sensor, a differential pressure transmitter and a flow integrator. The Bitobar flow sensor has a pressure pipe and a pressure head. The pressure pipe includes a total pressure pipe and a static pressure pipe. The upper part of the pressure head has a total pressure hole and a static pressure hole. The lower section of the pressure head is a cylindrical joint. The total pressure hole is connected to the total pressure pipe through a total pressure channel, and the static pressure hole is connected to the static pressure pipe through a static pressure channel. The total pressure pipe and the static pressure pipe are connected to the input end of the differential pressure transmitter, and the signal output end of the differential pressure transmitter is connected to the signal input end of the flow integrator. The Bitobar mass flowmeter of the above structure is only suitable for measuring only one fluid in the pipeline and the fluid is at room temperature The mass flow rate of the fluid in the pipeline under normal pressure. When the Bitobar mass flowmeter of the above structure is in use, the Bitobar flow sensor is inserted vertically into the pipeline from the side wall of the pipeline, and the center point of the total pressure hole and the static pressure hole is connected on the axis of the pipeline. The total pressure hole faces the incoming direction of the fluid, and the static pressure hole faces the outgoing direction of the fluid. When the fluid flows in the pipeline, the total pressure interface and the static pressure interface at the upper end of the pressure pipe respectively output the total pressure and static pressure of the fluid flowing in the pipeline. The total pressure and static pressure of the fluid flowing in the pipeline can be used to calculate the flow rate of the fluid in the pipeline according to the principles of fluid mechanics. Then, based on the density of the fluid in the pipeline at normal temperature and pressure, the mass flow rate of the fluid in the pipeline can be finally calculated in the flow integrator and displayed on the integrator.

However, when a plurality of mixed fluids flow in the pipeline and the fluids are at an abnormal temperature and pressure, the Bitobar mass flowmeter with the above structure cannot accurately measure the mass flow rate of the mixed fluids in the pipeline.

Summary of the invention

The technical problem to be solved by the present invention is to provide a Bitobar integrated mass flowmeter which does not require a measuring installation hole to be opened in a measured pipeline and is thus easy to install and disassemble.

In order to solve the above technical problems, the Bitobar integrated mass flowmeter of the present invention includes a Bitobar sensor, a differential pressure transmitter and a flow integrator, wherein the Bitobar sensor has a pressure head, a pressure pipe and a pipeline mounting seat, wherein the pressure pipe passes through the pipeline mounting seat, and an annular gap is formed between the pressure pipe and the pipeline mounting seat, and also includes a densitometer for measuring the density of a mixed fluid, wherein the input end of the densitometer is connected to the pipeline mounting seat through a sampling tube, and the signal output end of the densitometer is connected to the signal input end of the flow integrator; and also includes a drainage tube that can be extended into the pipeline, wherein the drainage tube passes through the pipeline mounting seat, and a temperature transmitter and a pressure transmitter are connected to the drainage tube, and the signal output ends of the temperature transmitter and the pressure transmitter are connected to the signal input end of the flow integrator.

The Bitobar integrated mass flowmeter using the above structure needs to first open a circular mounting hole on the pipe wall during installation and use. The radial dimension of the mounting hole is slightly larger than the sum of the lateral dimensions of the pressure pipe and the drainage pipe of the Bitobar flow sensor. The Bitobar flow sensor is installed on the pipe through the pipe mounting seat so that the pressure pipe and the drainage pipe are inserted into the pipe. Since an annular gap is formed between the pressure pipe and the pipe mounting seat in the present invention, a densitometer for measuring the density of the mixed fluid is also included. The input end of the densitometer is connected to the pipe mounting seat through a sampling tube, and its signal output end is connected to the signal input end of the flow integrator. According to the above technical features, the mixed fluid in the pipe will enter the sampling tube through the annular gap between the pressure pipe and the pipe mounting seat, and then the densitometer can measure the density of the mixed fluid in the pipe at room temperature and pressure and input the measurement result into the flow integrator. In addition, since it also includes a drainage pipe that can be inserted into the pipe, the drainage pipe passes through the pipe mounting seat, and the drainage pipe is connected to a temperature transmitter and a pressure transmitter. The temperature transmitter

The signal output end of the device and the pressure transmitter is connected to the signal input end of the flow integrator. After adopting the above technical features, the accurate temperature and pressure of the mixed fluid in the pipeline can be measured, and the measurement structure can be input into the flow integrator. Finally, the mass flow rate of the mixed fluid in the pipeline can be calculated in the flow integrator by combining the flow rate of the mixed fluid in the pipeline and the density of the mixed fluid at normal temperature and pressure, and using the actual temperature and pressure in the pipeline as compensation.

In summary, the Bitopa integrated mass flowmeter of the present invention can accurately measure the mass flow of mixed fluids in a pipeline.