Further study on the heat exchanger circuitry arrangement for an active chilled beam terminal unit

Chen, Can; Cai, Wenjian; Wang, Youyi; Chen, Lin

doi:10.1016/j.enbuild.2015.07.001

Cited by 17 publications

(4 citation statements)

References 25 publications

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“…When the primary air flow rate is too low, part of the primary air will flow out from the return air inlet directly because of the gravity and little return air will be inducted which will degrade the performance of the RIDU. Compared to the chilled beam [23][24][25][26][27][28], because the mixed air will exchange heat with the radiant panel, the induction ratio cannot be too high to prevent a reduction in the temperature difference between the mixed air and the pore radiant panel. However, a sufficient mixed air flow rate needs to be ensured to maintain a sufficient heat exchange efficiency.…”

Section: Resultsmentioning

confidence: 99%

Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

Zhang

2016

Energies

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Abstract:In this paper we proposed the novel air-conditioning system which combined induction ventilation and radiant air-conditioning. The indoor terminal device is the radiant induction-unit (RIDU). The RIDU is the induction unit combined with the pore radiant panel on which the copper pipes with rigid aluminum diffusion fins are installed. The two-stage evaporator chiller with the non-azeotropic mixture refrigerant is utilized in the system to reduce the initial investment in equipment. With the performance test and the steady state heat transfer model based on the theory of radiative heat transfer, the relationship between the induction ratio of the RIDU and the characteristic of the air supply was studied. Based on this, it is verified that the RIDU has a lower dew-point temperature and better anti-condensation performance than a traditional plate-type radiant panel. The characteristics of the radiation and convection heat transfer of the RIDU were studied. The total heat exchange of the RIDU can be 16.5% greater than that of the traditional plate-type radiant terminal.

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Section: Resultsmentioning

confidence: 99%

Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

Zhang

2016

Energies

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“…Generally, a 1-way system is used in customized applications, such as in hospital patient rooms, where maintaining local indoor air quality and thermal comfort is highly important [26]. A majority of the existing experimental and simulation studies have aimed to provide design guidelines by evaluating the ventilation and comfort performance of 2-way active chilled beams as terminal units [14,[27][28][29][30][31]. Providing efficient mixing with the room air by creating multi-directional or circular air distribution patterns, has proven to be a dominant advantage of the 4-way active chilled beam system [25].…”

Section: Introductionmentioning

confidence: 99%

“…The airflow pattern in the occupied zone is driven by a variety of factors, such as the level of internal heat gain [32], the location of heat gain [33], and the type [27] and symmetry [34] of the terminal units. It is worth mentioning that local thermal discomfort issues and energy consumption risks may still arise in 4-way active chilled beam systems because of improper installation.…”

Section: Introductionmentioning

confidence: 99%

Effect of active chilled beam layouts on ventilation performance and thermal comfort under variable heat gain conditions

Ming

Mustakallio

Kosonen

et al. 2023

Building and Environment

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“…It was found out that 2-circuits arrangement had the best performance instead of the 1-circuit heat exchanger that is widely used in ACB products. The heat exchanger of ACB terminal was further studied with respect to tube connecting sequences by Can et al [29]. An optimized scheme for the heat transfer capacity was proposed with a particle swarm optimization program.…”

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confidence: 99%

Air distribution and thermal comfort for active chilled beam systems

Wu¹

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During the past few decades, the active chilled beam (ACB) system has become increasingly prevalent worldwide as a promising air conditioning and mechanical ventilation (ACMV) system. It is acknowledged that ACB systems have the advantages of providing high energy efficiency, good thermal comfort, and satisfied noise control with a lower space requirement. In modern society, the thermal discomfort and excessive energy consumption are the two major concerns for ACMV systems. People, especially in developed countries, spend substantial of their time in air-conditioned rooms. The poor air quality and inferior thermal condition incur plenty of uncomfortable sensations and even give rise to sicknesses such as sick building syndrome. One of the most common and serious problems is sensation of draught, which is mainly caused by the unpleasant cooling of air movement. Therefore, it is significantly important to evaluate the air distribution and thermal comfort for ACB systems. However, the previous studies mainly focused on cooling capacity, energy-saving effect and mechanical optimization of ACB systems. The studies on air distribution and thermal comfort are still inadequate to provide a comprehensive perspective on ACB systems. In order to fulfil the gaps, the airflow pattern is experimentally and numerically studied for ACB systems. Through experiments, an un-uniform air distribution is found near the nozzles in ACB terminals and this found distribution has a great chance to cause uncomfortable feeling such as draught in the occupied zone. A three-dimensional computational fluid dynamics (CFD) model for ACB terminal is built and validated by particular experiments. A proper strategy to balance the air distribution is proposed and validated by CFD simulation. Besides, the velocity contours near the ceilings are captured and the characteristics of Coandă effect, self-similarity, and turbulence intensity for air jet are discussed under various air supply temperatures and pressures. In addition, the effects of the heat sources' configuration and strength on thermal comfort are experimentally investigated in a mock-up room with ACB systems. The full-scale

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Further study on the heat exchanger circuitry arrangement for an active chilled beam terminal unit

Cited by 17 publications

References 25 publications

Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

Effect of active chilled beam layouts on ventilation performance and thermal comfort under variable heat gain conditions

Air distribution and thermal comfort for active chilled beam systems

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