Maisotsenko cycle: technology overview and energy-saving potential in cooling systems (original) (raw)
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ADVANCED COOLING TOWER CONCEPT BASED ON THE MAISOTSENKO‐CYCLE - AN EXERGETIC EVALUATION
International Journal of Energy for a Clean Environment, 2011
The Maisotsenko-Cycle (M-Cycle) is a complex process associated with humid air. Heat transfer and evaporative cooling occur in a unique indirect evaporative cooler, resulting in product temperatures that approach dew point temperature. The different applications of the M-Cycle contribute to effective energy savings. By enhancing cooling towers with the M-cycle it is possible to (a) cool water to temperatures approaching dew point temperature, and (b) reduce the pressure drop and the required fan power. An exergetic analysis identifies the real thermodynamic inefficiencies and the potential of improvement of energy conversion systems. This paper discusses the results obtained from a detailed exergetic analysis of the M-Cycle applied to a cooling tower. In the analysis physical and chemical exergies are considered and the physical exergies of all material streams are split into their thermal and mechanical parts. The paper concludes with a sensitivity analysis.
International Journal of Heat and Mass Transfer, 2015
This paper investigates a mathematical simulation of the heat and mass transfer in the two different Maisotsenko Cycle (M-Cycle) heat and mass exchangers used for the indirect evaporative cooling in different air-conditioning systems. A two-dimensional heat and mass transfer model is developed to perform the thermal calculations of the indirect evaporative cooling process, thus quantifying the overall heat exchangers' performance. The mathematical model was validated against the experimental data. Numerical simulations reveal many unique features of the considered units, enabling an accurate prediction of their performance. Results of the model allow for comparison of the two types of heat exchangers in different applications for air conditioning systems in order to obtain optimal efficiency.
Overview of the Maisotsenko cycle – A way towards dew point evaporative cooling
The Maisotsenko Cycle (M-Cycle) is a thermodynamic conception which captures energy from the air by utilizing the psychrometric renewable energy available from the latent heat of water evaporating into the air. The cycle is well-known in the airconditioning (AC) field due to its potential of dew-point eva-porative cooling. However, its applicability has been recently expanded in several energy recovery applications. Therefore, the present study provides the overview of M-Cycle and its application in various heating, ventilation, and airconditioning (HVAC) systems; cooling systems; and gas turbine power cycles. Principle and features of the M-Cycle are discussed in comparison with conventional evaporative cooling, and consequently the thermodynamic limitation of the cycle is highlighted. It is reported that the standalone M-Cycle AC (MAC) system can achieve the AC load efficiently when the ambient air humidity is not so high regardless of ambient air temperature. Various modifications in MAC system design have been reviewed in order to investigate the M-Cycle applicability in humid regions. It is found that the hybrid, ejector, and desiccant based MAC systems enable a huge energy saving potential to achieve the sensible and latent load of AC in humid regions. Similarly, the overall system performance is significantly improved when the M-Cycle is utilized in cooling towers and evaporative condensers. Furthermore, the M-Cycle conception in gas turbine cycles has been realized recently in which the M-Cycle recuperator provides not only hot and humidified air for combustion but also recovers the heat from the turbine exhaust gases. The M-Cycle nature helps to provide the cooled air for turbine inlet air cooling and to control the pollution by reducing NO x formation during combustion. The study reviews three distinguished Maisotsenko gas turbine power cycles and their comparison with the conventional cycles, which shows the M-Cycle significance in power industry.
Application Potential of the M-Cycle Exchanger to Air Conditioning Systems in Poland
DEStech Transactions on Environment, Energy and Earth Sciences
In the article the performance of the advanced indirect evaporative air cooler has been investigated. The application of the heat and mass exchanger in an air conditioning systems have been analyzed according to the typical climatic conditions in Poland. The considered indirect evaporative air cooler is based on the cross-flow heat and mass exchanger model with the Maisotsenko cycle (M-Cycle). The main conclusion is that an application of heat and mass exchanger with the M-Cycle to the typical air conditioning systems to the typical climatic conditions in Poland is characterized by the high cooling efficiency.
Energy, 2014
In this paper a novel cross-flow HMX (heat and mass exchanger) utilizing the M-cycle (Maisotsenko cycle) for dew point indirect evaporative cooling has been tested for the performance evaluation in terms of thermal effectiveness and specific cooling capacity under various ambient and operational conditions. Additionally, the operational performance of the investigated HMX was examined on the base of developed model. The obtained results from the model prediction have been compared with the experimental data. The positive results of this validation indicated that the proposed model may be successfully used for prediction of operational performance of the investigated HMX. The analysis presented in this paper further demonstrates attractiveness and high efficiency of the novel M-cycle HMX used for indirect evaporative cooling in air conditioning units.
Engineering Applications of Computational Fluid Mechanics , 2020
In this work, a numerical and experimental study is performed to evaluate the affecting variables on energy efficiency of a novel regenerative evaporative cooler utilizing dew-point indirect evaporative cooling. For first time, an investigation is experimentally and numerically carried out to study the effects of the channel number on important parameters such as product temperature and humidity ratio. Investigations are carried out for five configurations with various channel numbers. The comparison of the numerical and experimental results is obtained and well accuracy observed. For the five studied configurations, the results show that with an increase in the number of channels, the outlet temperature decreases. For an inlet air flow rate of 100–600m3/h, the cooled outlet flow temperature changes to the range of 23.4–30.7°C, 19.7–28.3°C, 18–26.4°C, 17.2–25°C and 16.6–23.8°C. For the configurations with finned channels, the percentage of increase in produced air temperature reaches 11.5% for HMX B, 18.6% for HMX C, 23.4% for HMX D and 26.9% for HMX E, as compared with HMX A.
Energy, 2011
This paper provides a comparative study of the performance of cross-flow and counter-flow M-cycle heat exchangers for dew point cooling. It is recognised that evaporative cooling systems offer a low energy alternative to conventional air conditioning units. Recently emerged dew point cooling, as the renovated evaporative cooling configuration, is claimed to have much higher cooling output over the conventional evaporative modes owing to use of the M-cycle heat exchangers. Cross-flow and counter-flow heat exchangers, as the available structures for M-cycle dew point cooling processing, were theoretically and experimentally investigated to identify the difference in cooling effectiveness of both under the parallel structural/operational conditions, optimise the geometrical sizes of the exchangers and suggest their favourite operational conditions. Through development of a dedicated computer model and case-by-case experimental testing and validation, a parametric study of the cooling performance of the counter-flow and cross-flow heat exchangers was carried out. The results showed the counter-flow exchanger offered greater (around 20% higher) cooling capacity, as well as greater (15%e23% higher) dew-point and wet-bulb effectiveness when equal in physical size and under the same operating conditions. The crossflow system, however, had a greater (10% higher) Energy Efficiency (COP). As the increased cooling effectiveness will lead to reduced air volume flow rate, smaller system size and lower cost, whilst the size and cost are the inherent barriers for use of dew point cooling as the alternation of the conventional cooling systems, the counter-flow system is considered to offer practical advantages over the cross-flow system that would aid the uptake of this low energy cooling alternative. In line with increased global demand for energy in cooling of building, largely by economic booming of emerging developing nations and recognised global warming, the research results will be of significant importance in terms of promoting deployment of the low energy dew point cooling system, helping reduction of energy use in cooling of buildings and cut of the associated carbon emission.
Energy Saving Potential by Using Maisotsenko-Cycle in Different Applications
International Journal of Earth & Environmental Sciences, 2018
The Maisotsenko cycle (M-cycle) is a proven thermodynamic process which captures energy from the air, utilizing the psychometric renewable energy, available from latent heat of water evaporating into the air. In air conditioning, the M-cycle uniquely combines thermodynamic processes of heat transfer and evaporative cooling, in order to enable temperature of the product to approach ambient dew point temperature. The capturing energy from the latent heat of evaporation may be usedin electric energy generation, engine technology, water distillation with absolutely no carbon emissions. The principles of M-cycle can be used in any application which requires energy. Most popular application of the Maisotsenko cycle are the air conditioning systems; it is proven that M-Cycle can reduce the energy consumption up to 90% in comparison to traditional solutions. Besides the air conditioning systems, M-Cycle can also be used for effective water desalination, increasing the effectiveness of gas turbines and photovoltaic panels. The following paper discusses different applications of the Maisotsenko cycle and describes energy savings which can be obtained.
International Journal of Energy for a Clean Environment, 2011
porative cooling process, thus quantifying overall heat exchanger performance. This mathematical model accounts for many unique features of the cross-flow heat exchanger, enabling an accurate prediction of performance. Results of the model show high efficiency gains that are sensitive to various inlet conditions and allow for estimation of optimum operating conditions, including suitable climatic zones for the proposed unit.