A retractable air volume hood for measuring the air delivery volume of a spherical nozzle

Abstract

Provided in the invention is a telescopic air volume cover for measuring the blast amount of a spherical nozzle. telescopic air volume cover comprises a measuring base, a measuring frame base, a coverbody connecting base, a telescopic cover body, a hoop, a micromanometer and a temperature and humidity sensor. The measuring frame base includes a cylindrical measuring frame mounting seat and a cross-shaped measuring bracket. The measuring bracket includes a pressure leading seat, a measuring rod, a connecting rod and a rubber sleeve. The telescopic cover body is a corrugated pipe with a memoryfunction. The measuring base, the measuring frame base and the cover body connecting base are sequentially connected through a flange plate. The telescopic cover body is connected with the cover bodyconnecting base and a to-be-measured spherical nozzle; the micromanometer is connected with a pressure guide needle; and the temperature and humidity sensor is electrically connected with the micromanometer. The telescopic air volume cover having a simple structure is operated conveniently. The size of the cover body is adjusted and whether the sealing hole in the measuring rod is opened or not isjudged according to the measured size of the spherical nozzle; a corresponding measuring mode is selected at the micromanometer; and the blast amount of the spherical nozzle is measured multiple times by rotation to change the position of a measuring point at the concentric ring, so that the measuring precision of the blast amount of the spherical nozzle is greatly improved.

Description

technical field [0001] The invention relates to the field of air volume measurement, in particular to a retractable air volume cover for measuring the air volume of a spherical nozzle. Background technique [0002] With the rapid development of society, there are more and more tall spaces such as high-speed rail stations, airports, and tall industrial plants. In order to adjust the temperature and humidity of tall spaces and improve the indoor air quality, it is often necessary to supply air to the room through spherical nozzles. In order to meet the design requirements of the ventilation and air conditioning system in tall spaces, it is necessary to accurately measure the air supply volume of the spherical tuyere during the commissioning process to achieve efficient and energy-saving operation of the system, and at the same time achieve the purpose of accurately controlling indoor air parameters. [0003] In the design process of the existing air volume hood, the louver tuy...

AI Technical Summary

Problems solved by technology

However, the airflow characteristics of the outlet of the spherical nozzle are jet-like, which is very different from the airflow characteristics of the louver tuyere and the diffuser tuyere. Through experiments and numerical simulations, the air supply volume of various types of spherical nozzles is tested using the existing air volume hood. Measurement, the study found that the air volume value measured by the existing air volume hood to measure the small spherical nozzle is 2-3 times the actual air volume value. The error of this measurement result is very large, and it is difficult to meet the needs of actual engineering measurement.

At present, the improvement of the air volume hood is mostly focused on the adjustment of the air outlet, auxiliary brackets, and back pressure compensation to enhance the applicability of the air volume hood device, but the internal structure of the air volume hood has not been optimized, and the airflow at the outlet of the spherical nozzle cannot be measured on the measurement bracket. The velocity distribution tends to be evenly distributed, thereby improving the measurement accuracy of the air volume of the spherical nozzle

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