Container combination and reversing valve type pvtt method gas flow device

Abstract

The invention discloses a container combination and reversing valve type pVTt-method gas flow device comprising a standard container, a buffer container, an intelligent collection system, a control system, a front header, and a rear header. The standard container is provided with an inlet end valve, a combined selection valve and an outlet end valve. The front header is provided with a test pipeline. A nozzle clamp segment is arranged between the front header and the rear header. A gas outlet of the rear header is connected with one end of a connecting pipe and one end of a bypass pipe; the other end of the connecting pipe is connected with the outlet end valve. The other end of the bypass pipe is communicated with a gas inlet of the buffer container. The intelligent collection system collects pressure and temperature in the standard container, at a mounting port for an instrument to be tested, and in the test pipeline, the front header and the rear header before and after inflating, and collects inflating time. The container combination and reversing valve type pVTt-method gas flow device is applicable to detecting critical flow meters by a static method, detecting various gas flow meters by a dynamic method, and detecting high-accuracy standard meters.

Description

technical field [0001] The invention relates to a gas flow detection device, in particular to a container combination and reversing valve type pVTt method gas flow device. Background technique [0002] The pVTt method gas flow detection device is a widely used primary gas flow standard metering device and equipment. It has a high level of accuracy, and the measurement uncertainty U can reach 0.07% or higher. Venturi is usually used as a secondary standard. Primary standard devices and equipment for traceability of critical flow flowmeters such as nozzles and sonic nozzles. [0003] At present, whether the test pressure is positive pressure or negative pressure, the pVTt method gas flow device requires that the ratio of the pressure in the standard container before and after inflation to the pressure at the instrument under test must not be greater than the critical pressure ratio γ * , the γ * The value is related to the test medium, pressure, the structure of the tested c...

AI Technical Summary

Problems solved by technology

[0003] At present, whether the test pressure is positive pressure or negative pressure, the pVTt method gas flow device requires that the ratio of the pressure in the standard container before and after inflation to the pressure at the instrument under test must not be greater than the critical pressure ratio γ * , the γ * The value is related to the test medium, pressure, the structure of the tested critical flow gas flowmeter, etc., usually γ * Take it between 0.528 and 0.85, which limits the application and promotion of the current pVTt method gas flow detection device

The pVTt method gas flow device still has the following problems: (1) There is only one standard container; (2) The volume of the standard container is small, and the maximum flow value is small; (3) The flow range that can be verified is not wide and is specified as a certain range (4) Each device has only one turndown ratio and flow range, which cannot be combined; (4) It can only be used to detect the measurement characteristics of critical flow meters, and cannot detect other flow meters such as standard meters; (5) Due to the pVTt method When the gas flow device enters the air, the flow rate of the test pipeline changes with the pressure in the standard container, and the detection flow cannot be controlled or set; (6) The pVTt method gas flow device can only use the static method to detect the flow meter, that is, the flow meter at the beginning of the test The flow increases from zero to the set detection flow value, and the flow meter flow decreases from the set detection flow value to zero when it stops. When detecting flow meters other than the critical flow flow meter, the detection error will be large

Images