Variable-area critical flow flowmeter

Abstract

The invention discloses a variable-area critical flow flowmeter. The variable-area critical flow flowmeter comprises a gas input shell, a sealed nozzle and a gas output shell which are connected from front to back. A connecting shaft is installed in the gas input shell, a throttling body is installed in the sealed nozzle and the gas output shell, and the rear end of the connecting shaft and the throttling body are coaxially connected. A high-accuracy displacement sensor is coaxially installed at the front end of the connecting shaft, a specially-shaped center hole is formed in the sealed nozzle, the front portion of the throttling body is a cone, and a cylindrical shaft of the rear portion of the throttling body is connected with a motion mechanism used for driving the throttling body to axially move forwards and backwards. Standard flanges are installed on the two gas shells and an input gas pressure intensity sensor and an output gas pressure intensity sensor are installed on the side walls of the gas input shell and the gas output shell respectively. By the adoption of the variable-area critical flow flowmeter, based on the variable-area nozzle, the position of a throttling device is controlled so as to accurately control the throat area and acquire the determined flow, portability is high, the flowmeter is easily connected with a pipeline, and labor cost and the workload are reduced.

Description

technical field [0001] The invention designs a gas flowmeter, and more specifically relates to a variable-area critical flowmeter that can be directly used to measure pipeline gas flow. Background technique [0002] Flow is an important parameter in modern life and production. Most of industrial production processes, scientific experiments and various economic calculations need to involve flow. Since the 20th century, due to the demand for flow measurement in energy measurement, environmental protection, transportation and other application fields, flow measurement technology has developed rapidly. With the introduction of the national "energy saving and emission reduction" strategy, the measurement of energy, waste water and waste gas has become an important topic in the field of flow measurement. The critical flow Venturi nozzle has good flow metering stability, simple and reliable principle, so it is widely used as a flow control instrument or a standard meter in a stand...

AI Technical Summary

Problems solved by technology

[0003] At present, the main problem with critical flow nozzles is that the flow measurement range is "1", that is, one nozzle is only one flow, but the flow measurement often has a large range, so the nozzles need to be designed in different sizes

In addition, changing the flow rate can only change the upstream pressure, increase the number of nozzles in parallel or change the nozzles, which is often impossible to achieve in industrial applications, so its popularization and application are greatly limited

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