US-12618753-B2 - Measurement apparatus for measuring air flowing inside pipeline

US12618753B2US 12618753 B2US12618753 B2US 12618753B2US-12618753-B2

Abstract

Various embodiments include a testing apparatus capable of testing gas flowing in a duct. The apparatus may include: a housing; a sampling tube extending from the housing to be inserted into the duct, the sampling tube including a gas entry channel and a gas exit channel isolated from each other, with a gas inlet of the gas entry channel and a gas outlet of the gas exit channel disposed in a part of the sampling tube leading into the duct and disposed at the same side of the sampling tube, wherein the gas inlet and the gas outlet have matching gas through-flow areas; and a sensor module disposed in the housing and in gas communication with the gas entry channel to test gas sampled from the gas entry channel.

Inventors

Fang Zhao
Ning Liu
Shi Ding Xue
Long Song
Dian Dong
Ming Xue Xu
Meng Hui Liu

Assignees

SIEMENS SCHWEIZ AG

Dates

Publication Date: 20260505
Application Date: 20200109

Claims (12)

1 . A testing apparatus capable of testing gas flowing in a duct with a primary flow direction, the apparatus comprising: a housing; a sampling tube extending from the housing to be inserted into the duct, the sampling tube including a gas entry channel and a gas exit channel isolated from each other, with a gas inlet of the gas entry channel and a gas outlet of the gas exit channel both disposed in a sidewall of the sampling tube facing into the primary flow of the gas, wherein the gas inlet and the gas outlet have matching gas through-flow areas; and a sensor module disposed in the housing and in gas communication with the gas entry channel to test gas sampled from the gas entry channel.
2 . The testing apparatus as claimed in claim 1 , wherein a gas pressure due to gas flow in the duct at the gas inlet is substantially equal to a gas pressure due to gas flow in the duct at the gas outlet.
3 . The testing apparatus as claimed in claim 1 , wherein the gas inlet and the gas outlet are adjacent to each other.
4 . The testing apparatus as claimed in claim 1 , wherein the sensor module includes: an inlet and an outlet; and a fan leading a gas flow in through the inlet and out through the outlet.
5 . The testing apparatus as claimed in claim 1 , wherein the gas inlet and the gas outlet are both at a windward side of the sampling tube with respect to a gas flow direction in the duct.
6 . The testing apparatus as claimed in claim 1 , wherein the gas inlet and the gas outlet are both at a leeward side of the sampling tube with respect to a gas flow direction in the duct.
7 . The testing apparatus as claimed in claim 1 , wherein the gas inlet and the gas outlet are both on an end face of an end of the sampling tube that extends into the duct.
8 . The testing apparatus as claimed in claim 1 , wherein the sampling tube is integrally formed and has a dividing part dividing the sampling tube into the gas entry channel and the gas exit channel.
9 . The testing apparatus as claimed in claim 8 , wherein the gas inlet and the gas outlet are aligned in the longitudinal direction of the sampling tube.
10 . The testing apparatus as claimed in claim 1 , wherein at least one of the gas inlet and the gas outlet has multiple gas holes.
11 . The testing apparatus as claimed in claim 1 , wherein: the sensor module has an inlet and an outlet; the gas entry channel is connected in a sealed manner to the inlet of the sensor module; the outlet of the sensor is in gas communication with an interior space of the housing; and the gas exit channel is connected into the housing in a sealed manner.
12 . The testing apparatus as claimed in claim 1 , wherein the sensor module comprises a PM2.5 sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Stage Application of International Application No. PCT/CN2020/071079 filed Jan. 9, 2020, which designates the United States of America, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present disclosure relates to ventilation systems. Various embodiments of the teachings herein include testing apparatuses and/or methods for testing gas flowing in a duct, e.g. a testing apparatus for testing air quality in a ventilation duct in a ventilation system. BACKGROUND Ventilation ducts are generally arranged in commercial buildings and civil residential buildings, for example to ventilate indoor areas with fresh air, i.e. as common fresh air systems. In general, it is necessary to monitor the cleanliness of gas in such ventilation ducts, for example the dust concentration, and especially the PM2.5 concentration, etc. At present, there are a variety of apparatuses and methods on the market for measuring the dust concentration in ducts through which gases flow, in particular in ducts in air conditioning systems (HVAC). In this regard, two aspects which have received a lot of attention are dust sensors and gas sampling methods. A currently known apparatus for measuring the concentration of dust in gas flowing in a duct comprises a housing, a sensor module disposed in the housing, and a sampling tube projecting from the housing. The sensor module is for example a common dust sensor module. The sampling tube comprises a gas entry channel and a gas exit channel, wherein the gas entry channel and gas exit channel each have one end inserted into the duct in such a way as to be sealed with respect to the surrounding environment, and another end connected to the housing in a sealed manner. The gas entry channel has a gas inlet on a sidewall thereof at a part where it leads into the duct, and correspondingly, the gas exit channel has a gas outlet on a sidewall thereof at a part where it leads into the duct, wherein the gas inlet faces windward with respect to the flow direction of gas in the duct, and the gas outlet faces leeward with respect to the flow direction of gas in the duct. The sensor module comprises an inlet and an outlet, and the gas to be tested flows in through the sensor inlet via the gas entry channel and out through the outlet, and is discharged into the duct via the gas exit channel, so that dust in the through-flowing gas is measured by means of the sensor module. In such a configuration, the sensor module will be affected by high flow speeds, low flow speeds and unstable gas flow in the duct during measurement. PM2.5 sensors are especially susceptible due to their high sensitivity. Thus, in such a conventional wind passage air sampling method, the sensor module will directly cause inaccuracy in the measurements performed. Furthermore, in such a conventional wind passage air sampling method, a separate gas pump is generally used in combination with two rubber or plastic tubes to draw air from the duct into the sensor module. In such a situation, where a gas pump is used to provide a gas pressure difference between the gas entry channel and the gas exit channel, air in the duct will thereby be sucked into the housing in which the sensor module is installed. Providing a gas pump increases the number of additional components, so more space is taken up and the cost is higher. The gas pump generally has a shorter service life than the sensor module and the sampling tube, so the use of a gas pump will shorten the service life of the entire apparatus for measuring dust in the duct. The gas pump will also produce considerable noise. Moreover, gas pumps generally need to be used in combination with soft tubes such as rubber tubes or plastic tubes, and this will affect the stability of the entire apparatus. SUMMARY Teachings of the present disclosure provide a testing apparatus capable of testing gas flowing in a duct, wherein the gas flowing in the duct can be sampled more accurately by means of the apparatus, making it possible to provide more precise measurement results. The systems and/or methods described herein include testing apparatuses to lead in air without the need for an independent gas pump, and/or to increase the flexibility in terms of installation direction of the testing apparatus compared to a conventional sampling apparatus, thus increasing the convenience of use. For example, some embodiments include a testing apparatus capable of testing gas flowing in a duct (1), comprising: a housing (4); a sampling tube (3), extending out from the housing (4) and adapted to be inserted into the duct (1), wherein the sampling tube (3) has a gas entry channel (5) and a gas exit channel (6) isolated from each other, with a gas inlet (51) of the gas entry channel (5) and a gas outlet (61) of the gas exit channel (6) being disposed in a part of the sampling tube (3) that leads into the duct