Analysis of variable air volume unit pressure sensor factors with specific reference to measurement of low air velocity

The knowledge of the air velocity distribution in the supply jets is essential when designing ventilation and air conditioning systems. In this study, we tested and analyzed the velocity distributions in the radial wall jets—these jets are commonly used in ventilated rooms. Tests included jets from two ceiling diffusers of different constructions, at three airflow rates. The mean air speed distributions were measured with a 16-channel hot-sphere anemometer both in the self-similarity zone and in the terminal zone. A specially developed method of converting the mean speed to mean velocity was used. The measurement results show that the spread coefficients of the jets from both diffusers were the same, but the positions of the virtual origin were different. Due to the friction of the jet with the ceiling and the transfer of momentum to the recirculating flows, the momentum flux in the self-similarity zone decreased by up to 50%. An improved method for calculating velocity distributions in radial wall jets was developed and validated. This method takes into account the decrease of momentum, non-zero position of the jet origin, and faster velocity decrease in the terminal zone. A reliable method of predicting air velocity distribution in radial wall jets (RWJs) from ceiling diffusers may allow to properly select the diffuser size, its location, and the range of flow rate changes. The design process for variable air volume systems can be facilitated.

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35. Recommended Methods to Evaluate Performance of Variable Air Volume Fume Hood Systems

10.3320/1.2759035 ◽

2006 ◽

Author(s):

T. Smith

Keyword(s):

Fume Hood ◽

Variable Air Volume ◽

Air Volume

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The Analysis for Energy Consumption of Marine Air Conditioning System Based on VAV and VWV

E3S Web of Conferences ◽

10.1051/e3sconf/20183804012 ◽

2018 ◽

Vol 38 ◽

pp. 04012

Author(s):

Sai Feng Xu ◽

Xing Lin Yang ◽

Zou Ying Le

Keyword(s):

Energy Consumption ◽

Energy Saving ◽

Air Conditioning ◽

Water Volume ◽

Pump System ◽

Air Conditioning System ◽

Variable Air Volume ◽

Air Volume ◽

Marine Air ◽

Variable Water

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins’ dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.

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