Throat pressure tapping nozzle and device using same

Abstract

The invention provides a throat pressure tapping nozzle and a device using the same. The throat pressure tapping nozzle is characterized in that a nozzle body, the throat and a rear expanding sectionare of an overall structure; and the throat is provided with a pressure tapping hole, and the pressure tapping hole of the throat is perpendicular to the axis of the nozzle body and conducts straighthole pressure tapping. The throat pressure tapping nozzle is applied to the measuring device for measuring the water flow of a steam turbine, machining can be facilitated, the structure and the technology are simplified, using reliability and safety are improved, the verifying pass percent is increased, and the measuring precision is improved.

Description

technical field [0001] The invention relates to the field of measuring instruments, in particular to a throat pressure-taking nozzle and a device using the nozzle. Background technique [0002] In modern large-scale thermal power generation systems, it is necessary to calculate the heat consumption rate and steam consumption rate of the steam turbine. To calculate the heat consumption rate and steam consumption rate of the steam turbine, it is necessary to accurately know the flow rate entering the steam turbine. Low β value throat pressure ASME PTC6 The .0 nozzle is a standard flow meter for measuring the water flow entering the steam turbine. The ASME PTC6.0 nozzle with low β value throat pressure can be used as the benchmark for flow value transmission and is an important equipment for steam turbine verification. [0003] According to the installation position, the flowmeter of the power plant to measure the water entering the steam turbine is divided into: the downstream...

AI Technical Summary

Problems solved by technology

Disadvantages of this structure: 1. The front and rear straight pipe sections are an integral structure, which cannot be realized in technology; 2. If the front and rear straight pipe sections have a two-section structure, it will inevitably cause the pressure-taking pipe to pass through the weld seam. For high-pressure and high-temperature media 3. The throttling part adopts the integrated structure of the nozzle and the throat, and the rear expansion section and the throat adopt a welded structure. Defects such as bosses, depressions, and dislocations are prone to occur at the connection parts. It has an impact on the flow field and reduces the uncertainty of flow measurement; 5. The pass rate of factory inspection is low

Disadvantages of this structure: 1. It is difficult to ensure the coaxiality of the nozzle axis and the front straight pipe section; 2. The nozzle throat pressure hole adopts a 4-section broken line design, which is complex in process, difficult in processing, high in cost, and prone to burrs and misalignment and other defects, which are not easy to detect and seriously affect the flow measurement; 3. The nozzle adopts a three-stage structure, and the accuracy is not easy to improve

Disadvantages of this structure: 1. It is difficult to ensure the coaxiality of the nozzle axis and the front straight pipe section; 2. The nozzle throat pressure hole adopts a 4-section broken line design, which is complex in process, difficult in processing, high in cost, and prone to burrs and misalignment and other defects, and it is not easy to check and find, which seriously affects the flow measurement; 3. The inspection pass rate is low; currently there are also methods such as Image 6 The nozzle structure shown, but also has the above disadvantages, but the processing is slightly easier

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