Effects of Variable Diffuser Vanes on Performance of a Centrifugal Compressor with Pressure Ratio of 8.0

Ebrahimi, Mohsen; Huang, Qiangqiang; He, Xiao; Zheng, Xinqian

doi:10.3390/en10050682

Cited by 16 publications

(2 citation statements)

References 22 publications

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“…The plate's position changes in response to a signal from the controller or the thermostat in the area it serves [55]. A VA diffuser's nominal airflow is about 150 cfm at 0.05 pressure drop, or twice the flow rate of a swirl diffuser [56].…”

Section: Ufad System Componentsmentioning

confidence: 99%

A Revisit to Recent Developments in the Underfloor Air Distribution Systems

Ahmad,

Saxena,

Yadav

et al. 2023

E3S Web Conf.

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Underfloor air distribution, also known as UFAD, is a technique of providing the space conditioning in offices as well as other public spaces. Because of the substantial benefits which it can provide, it is progressively being regarded as a major alternative to the conventional ceiling-based air distribution systems. This is due to the fact that the UFAD is a technique of providing the space conditioning in the public spaces. This method delivers cooled air directly into the inhabited zone of the building by making advantage of the open space that is created (the underfloor plenum) that exists between the structural concrete slab as well as the underside of a raised access floor system. Air may be supplied through a multiplicity of the supply outlets positioned at the floor level (this is the most typical configuration), or it can be integrated into the structure of the furniture and walls. This paper provides a recent development in the field of HVACs that have employed UFAD systems for improving their effectiveness as well as thermal comfort of humans. UFAD has the potential to assist in the enhancement of a building’s energy efficiency, indoor air quality, occupant comfort, and sustainable practises. The future scope of UFAD is significant, and it has the potential to become a mainstream technology in the building industry.

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Section: Ufad System Componentsmentioning

confidence: 99%

A Revisit to Recent Developments in the Underfloor Air Distribution Systems

Ahmad,

Saxena,

Yadav

et al. 2023

E3S Web Conf.

View full text Add to dashboard Cite

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“…They showed that a reduction in the leading edge angle results in a shift of the compressor operating range towards lower mass flow rates. By implementing an actuation mechanism, which allows the flexible pivoting of the diffuser vanes, the operating range of the compressor can be adjusted depending on the operating conditions [13,14]. However, gaps between end walls and diffuser vanes, which are necessary for a flexible pivoting concept, cause aerodynamic losses and thus reduce efficiency.…”

Section: Introductionmentioning

confidence: 99%

Experimentally Validated Extension of the Operating Range of an Electrically Driven Turbocharger for Fuel Cell Applications

2021

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From an aerodynamic point of view, the electric turbocharger for the air supply of an automotive fuel cell faces difficult requirements: it must not only control the pressure level of the fuel cell, but it also has to operate with very high efficiency over a wide range. This paper explores features for the compressor and the turbine of an existing electric turbocharger, which are intended to meet the specific requirements of a fuel cell in an experimentally validated numerical study. Adjustable diffuser or nozzle vanes in the compressor and turbine achieve wider operating ranges but compromise efficiency, especially because of the necessary gaps between vanes and end walls. For the turbine, there are additional efficiency losses since the pivoting of the nozzle vanes leads to incidence and thus to flow separation at the leading edge of the nozzle vanes and the rotor blades. An increase in the mass flow and a slight efficiency improvement of the turbine with the low solidity nozzle vanes counteracts these losses. For the compressor, a reduction in the diffuser height and its influence over the operating range and power consumption yields an increase in surge margin as well as in maximum efficiency.

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