Comparative study of the performance of the M-cycle counter-flow and cross-flow heat exchangers for indirect evaporative cooling – Paving the path toward sustainable cooling of buildings

Zhan, Changhong; Duan, Zhiyin; Zhao, Xudong; Smith, Stefán Thor; Jiang, Hong; Riffat, Saffa

doi:10.1016/j.energy.2011.10.019

Cited by 211 publications

(76 citation statements)

References 15 publications

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“…The lowest value of humidity ratio was 0.027 kg kg -1 at the ambient temperature 25°C with 1.5 m s -1 inlet air velocity and the highest value of humidity ratio was 0.038 kg kg -1 at the ambient temperature 40°C with 6.0 m s -1 inlet air velocity. These results agreed with those obtained by Zhan et al [15] whose found the humidity ratio increased with increasing the inlet air temperature.…”

Section: Model Experimentationsupporting

confidence: 83%

“…There are several researchers have been studied cooling energy, Scientists studied that the cooling energy is a significant part of the energy needed in buildings [7][8][9][10][11][12][13][14][15][16]. The need for cooling in buildings is increasing due to higher levels of targeted indoor environment in addition to the impacts of the global warming.…”

Section: Introductionmentioning

confidence: 99%

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Performance of Direct Evaporative Cooling System under Egyptian Conditions

Khater¹

2014

J Climatol Weather Forecasting

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The main objective of this research is to optimize the parameters affecting the performance of the direct evaporative cooling system, to achieve that, a mathematical model of heat and mass balance of the evaporative cooling pads was developed to predict most important factors affecting the performance of the system. The model was able to predict the temperature, humidity ratio, wet bulb effectiveness, dew point effectiveness and temperaturehumidity index of outlet air at different ambient air temperatures (25, 30, 35 and 40°C), different inlet air velocities (1.5, 3, 4.5 and 6 m s -1 ), ambient air humidities (0.01, 0.02, 0.03 and 0.04 kg kg -1 ) and different lengths of pad (0.5, 1.0, 1.5 and 2.0 m). The results showed that the outlet temperature increases with increasing ambient temperature, inlet air velocity, ambient air humidities and lengths of pad. The results also showed that the wet bulb effectiveness ranged from 0.927 to 1.086. The dew point effectiveness ranged from 0.561 to 0.747. The humidity ratio ranged from 0.027 to 0.035 kg kg -1 . The temperature-humidity index ranged from 21.15 to 33.56°C on study treatments. The predicted outlet temperatures were in a reasonable agreement with those measured, where, it ranged 17.027 to 29.978°C theoretically while it was from 19.605 to 30.748°C experimentally. The prediction of temperature determines the optimum condition of plant growth in greenhouse, so that the model helps this optimization.

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Section: Model Experimentationsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Performance of Direct Evaporative Cooling System under Egyptian Conditions

Khater¹

2014

J Climatol Weather Forecasting

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“…So, if we aim to minimize water consumption, the lowering of the working stream mass flow is the best solution (the cooler consumes less than 1.5 kg w /kWh c ). 8 There is no doubt about the effect of the reduction of the product stream flow on the improvement of the cooler efficiency. For λ = 1:2, the cooler reaches a 115% efficiency (while for λ = 1:1 would lead to 107%), "gaining" 2°C of additional cooling.…”

Section: Resultsmentioning

confidence: 99%

Maisotsenko cycle: technology overview and energy-saving potential in cooling systems

Rogdakis¹,

Tertipis²

2015

EECT

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The present paper deals with an overview of Maisotsenko cycle (M-cycle). This cycle is an indirect evaporative cooling-based cycle, which utilizes a smart geometrical configuration for the air distribution. The achievement of this geometry is the high efficiency of the cycle, as it produces cold air of temperature lower than the wet-bulb ambient air temperature. As the energy source of this cooler is water rather than electricity, the usage of M-cycle-based coolers leads to significant energy saving, more than 80% in terms of electricity. The heat and mass exchanger is analyzed and described in detail, so the specifications of M-cycle will be clear and understandable. The operation of the standard configuration of M-cycle is studied thereafter and useful conclusions are carried out, about the efficiency and the energy consumption (electricity and water). Finally, the energy-saving potential is estimated in conventional cooling systems, in terms of electricity and capital cost, in order to evaluate the financial benefit of M-cycle application: the pay-back period is calculated equal to about 2.5 years (as the result of the replacement of conventional systems with M-cycle-based ones). The study is to be a useful tool to anyone interested in energy saving in buildings and in industrial plants, as the operating cost, which is strongly affected by the cooling demand, is significantly reduced by the application of M-cycle.

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“…Zhan [111] found that for optimum performance, the optimum flow rate ratio of working-to-product air was about 50%, and the dimensionless channel length (ratio of channel length to height) should be between 100 to 300. And it has also been shown to exhibit greater (over 15%) cooling effectiveness, when operated in counter flow configuration compared to cross flow [109].…”

Section: Indirect Evaporative Coolersmentioning

confidence: 99%

“…Generally, the dew point saturation efficiency can be between 55 -85%, however, the wet-bulb efficiency (based on the wet-bulb temperature) can be as 20 The DPEC has been studied by several researchers [98,109,110]. Zhan [111] found that for optimum performance, the optimum flow rate ratio of working-to-product air was about 50%, and the dimensionless channel length (ratio of channel length to height) should be between 100 to 300.…”

Section: Indirect Evaporative Coolersmentioning

confidence: 99%

Solar pond powered liquid desiccant evaporative cooling

Elsarrag

Igobo

Alhorr

et al. 2016

Renewable and Sustainable Energy Reviews

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Liquid desiccant cooling systems (LDCS) are energy efficient means of providing cooling, especially when powered by low-grade thermal sources. In this paper, the underlying principles of operation of desiccant cooling systems are examined, and the main components (dehumidifier, evaporative cooler and regenerator) of the LDCS are reviewed. The evaporative cooler can take the form of direct, indirect or semi-indirect. Relative to the direct type, the indirect type is generally less effective. Nonetheless, a certain variant of the indirect type -namely dew-point evaporative cooler -is found to be the most effective amongst all. The dehumidifier and the regenerator can be of the same type of equipment: packed tower and falling film are popular choices, especially when fitted with an internal heat exchanger. The energy requirement of the regenerator can be supplied from solar thermal collectors, of which a solar pond is an interesting option especially when a large scale or storage capability is desired.

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Comparative study of the performance of the M-cycle counter-flow and cross-flow heat exchangers for indirect evaporative cooling – Paving the path toward sustainable cooling of buildings

Cited by 211 publications

References 15 publications

Performance of Direct Evaporative Cooling System under Egyptian Conditions

Performance of Direct Evaporative Cooling System under Egyptian Conditions

Maisotsenko cycle: technology overview and energy-saving potential in cooling systems

Solar pond powered liquid desiccant evaporative cooling

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