Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
2,291
result(s) for
"Evaporative cooling."
Sort by:
The architecture of natural cooling
\"Overheating in buildings is commonplace. This book describes how we can keep cool without conventional air-conditioning: improving comfort and productivity while reducing energy costs and carbon emissions. It provides architects, engineers and policy makers with a 'how-to' guide to the application of natural cooling in new and existing buildings. It demonstrates, through reference to numerous examples, that natural cooling is viable in most climates around the world. The book includes: Guidance on the principles & strategies that can be adopted. Discussion of how designers integrate natural cooling in their buildings. Explanation of simplified tools for performance assessment. A review of components and controls. A detailed evaluation of building case studies from the USA, Europe, India and China. This book is not just for the technical specialist, as it also provides a general grounding in environmental design. Importantly, it demonstrates that understanding our environment, rather than fighting it, will help us to live sustainably in our rapidly warming world.\" -- Provided by publisher.
Book
Artificial Intelligence for the Prediction of the Thermal Performance of Evaporative Cooling Systems
The present study reports the development of a deep learning artificial intelligence (AI) model for predicting the thermal performance of evaporative cooling systems, which are widely used for thermal comfort in different applications. The existing, conventional methods for the analysis of evaporation-assisted cooling systems rely on experimental, mathematical, and empirical approaches in order to determine their thermal performance, which limits their applications in diverse and ambient spatiotemporal conditions. The objective of this research was to predict the thermal performance of three evaporation-assisted air-conditioning systems—direct, indirect, and Maisotsenko evaporative cooling systems—by using an AI approach. For this purpose, a deep learning algorithm was developed and lumped hyperparameters were initially chosen. A correlation analysis was performed prior to the development of the AI model in order to identify the input features that could be the most influential for the prediction efficiency. The deep learning algorithm was then optimized to increase the learning rate and predictive accuracy with respect to experimental data by tuning the hyperparameters, such as by manipulating the activation functions, the number of hidden layers, and the neurons in each layer by incorporating optimizers, including Adam and RMsprop. The results confirmed the applicability of the method with an overall value of R2 = 0.987 between the input data and ground-truth data, showing that the most competent model could predict the designated output features (Toutdb, wout, and Eoutair). The suggested method is straightforward and was found to be practical in the evaluation of the thermal performance of deployed air conditioning systems under different conditions. The results supported the hypothesis that the proposed deep learning AI algorithm has the potential to explore the feasibility of the three evaporative cooling systems in dynamic ambient conditions for various agricultural and livestock applications.
Journal Article
Evaporative Cooling Integrated with Solid Desiccant Systems: A Review
Evaporative cooling technology (ECT) has been deemed as an alternative to the conventional vapor-compression air conditioning system for dry climates in recent years due to its simple structure and low operating cost. Generally speaking, the ECT includes two types of different technologies, direct evaporative cooling (DEC) and indirect evaporative cooling (IEC). Both technologies can theoretically reduce the air temperature to the wet-bulb temperature of outdoor air. The major difference between these two technologies is that DEC will introduce extra moisture to the supply air while IEC will not. The enhanced IEC, Maisotsenko-cycle (M-cyle) IEC, can even bring down the air temperature to the dew point temperature. The ECT integrated with solid desiccant systems, i.e., solid desiccant-assisted evaporative cooling technologies (SDECT), could make the technology applicable to a wider range of weather conditions, e.g., weather with high humidity. In this paper, the recent development of various evaporative cooling technologies (ECT), solid desiccant material and the integration of these two technologies, the SDECT, were thoroughly reviewed with respect to their configuration, optimization and desiccant unit improvement. Furthermore, modeling techniques for simulating SDECT with their pros and cons were also reviewed. Potential opportunities and research recommendations were indicated, which include improving the structure and material of M-cycle IEC, developing novel desiccant material and optimizing configuration, water consumption rate and operation strategy of SDECT system. This review paper indicated that the SDECT system could be a potential replacement for the conventional vapor-compressed cooling system and could be applied in hot and humid environments with proper arrangements.
Journal Article
Wettability Gradient-Induced Diode: MXene-Engineered Membrane for Passive-Evaporative Cooling
HighlightsEngineering MXene into electrospun nanofibers can effectively enhance its thermal emissivity and conductance, and the unidirectional water transport of the wettability-gradient-induced-diode (WGID) membrane displayed diode-like properties with wettability gradient by tailoring the water contact angle of each single layer.The WGID membrane could achieve a cooling temperature of 1.5 °C in the “dry” state, and 7.1 °C in the “wet” state, with high emissivity of 96.40% in the MIR range, superior thermal conductivity of 0.3349 W m−1 K−1.Zero-energy-consumption for personal cooling management via multiple heat dissipation pathways, including thermal radiation, conduction, and evaporation.Thermoregulatory textiles, leveraging high-emissivity structural materials, have arisen as a promising candidate for personal cooling management; however, their advancement has been hindered by the underperformed water moisture transportation capacity, which impacts on their thermophysiological comfort. Herein, we designed a wettability-gradient-induced-diode (WGID) membrane achieving by MXene-engineered electrospun technology, which could facilitate heat dissipation and moisture-wicking transportation. As a result, the obtained WGID membrane could obtain a cooling temperature of 1.5 °C in the “dry” state, and 7.1 °C in the “wet” state, which was ascribed to its high emissivity of 96.40% in the MIR range, superior thermal conductivity of 0.3349 W m−1 K−1 (based on radiation- and conduction-controlled mechanisms), and unidirectional moisture transportation property. The proposed design offers an approach for meticulously engineering electrospun membranes with enhanced heat dissipation and moisture transportation, thereby paving the way for developing more efficient and comfortable thermoregulatory textiles in a high-humidity microenvironment.
Journal Article
Experimental Verification of a Method for Improving the Efficiency of an Evaporative Tower Using IEC
This paper analyses the impact of inlet air precooling on the efficiency and electricity consumption of an open-type evaporative cooling tower. An Indirect Evaporative Cooler (IEC) was used to reduce the inlet air temperature, and its influence on system efficiency was experimentally evaluated. Although IEC units and the Maisotsenko cycle are increasingly discussed in the literature, no research to date has considered their effect on evaporative tower efficiency under actual operating conditions. For this purpose, a test stand was constructed comprising an open cooling tower and an IEC unit. The system operated automatically for 2952 h, corresponding to a full cooling season in Poland. Two sets of data collected during cooling tower operation were analysed: without precooling (Stage I) and with precooling using IEC (Stage II). Measurements were recorded every 10 s. Additionally, tests were conducted at elevated thermal loads and peak ambient temperatures. The comparative analysis concluded that air precooling using IEC reduced the cooling tower’s electricity consumption by approximately 15% and increased the SCOP of the cooling tower by 30%. This demonstrates the significant potential of the proposed solution.
Journal Article
Modeling of Indirect Evaporative Cooling Systems: A Review
Air-to-air indirect evaporative cooling (IEC) systems are particular heat exchangers that use the latent heat of evaporation of water to cool down an air stream, without increasing its specific humidity, thus guaranteeing adequate thermohygrometric conditions in the refrigerated environment with low energy consumption. Dew-point indirect evaporative cooling (DIEC) systems are based on the IEC technology, but they recirculate a part of the air taken from the room to be refrigerated, in order to possibly achieve a lower air temperature. IEC and DIEC systems are becoming increasingly common these years, as they can ensure a good efficiency, minimizing the environmental impact of the air-conditioning system. Consequently, it has been necessary to develop models, both analytical and numerical, to quickly and accurately design this type of system and to predict their performance. This paper presents a review of the analytical and numerical models developed specifically for IEC and DIEC systems, highlighting their method, main innovations and advantages, and possible limitations. From this analysis, it emerged that analytical models have been developed since the late 1990s and only few of them are suitable for DIEC heat exchangers, while numerical models for both IEC and DIEC systems are gaining popularity in recent years. Almost all the analyzed models have been validated by comparison with numerical and/or experimental data, showing a maximum discrepancy within 10% in the majority of the cases. However, the validations were performed for a few specific cases, so in real applications it might be difficult to associate the model boundary conditions and the heat exchangers operating conditions, such as nozzles orientations, plates materials, water flow rates, and configurations. Another common limitation concerns the modeling of some properties, as wettability factor and air density, which might affect the accuracy of the results.
Journal Article
A numerical and experimental study on the energy efficiency of a regenerative Heat and Mass Exchanger utilizing the counter-flow Maisotsenko cycle
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 100-600 m
3
/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.
Journal Article
A Prototype and Efficiency Analysis of Indirect Regenerative Evaporative Cooling System for Electronics
This paper presents an innovative solution based on the Indirect Regenerative Evaporative Cooling (IREC) concept for high-power density electronics. The technology relies on forced convective cooling by air that is additionally cooled via evaporation. The system comprises dry and wet channels for the cooled and wet air, respectively; water is delivered through porous membranes in the wet channels. The novelty relative to HVAC-type exchangers (based on IREC technology) is a full flow return configuration, in which the entire stream from the dry channels is redirected into the wet channels. The performance benefits become pronounced at high ambient temperatures, where traditional forced convection may be insufficient; inlet air absolute humidity is a key factor governing efficiency. The authors present a developed prototype, a simplified thermal analysis, measurement results, and a discussion of IREC applicability to electronics cooling. The results indicate feasibility and highlight the potential of the proposed design for the energy-efficient thermal management of sensitive electronic equipment.
Journal Article
Comparative Life Cycle Analysis for Duct Air Conditioning Systems Based on Evaporative and Vapor Compression Technologies
The environmental impact of innovative indirect regenerative evaporative cooling (IREC) technology is analyzed using the life cycle assessment. This study compared typical equipment using this technology from Innovative Ideas LLC with available-on-the-market traditional vapor compression ducted air conditioning systems as the closest analogous representatives of the vapor compression technology. For comparison, units with the same cooling capacity (5 kW) were selected. The endpoint indicators demonstrated that the air conditioning systems using IREC technology had lower environmental load compared to the vapor compression system by 29–70%, depending on the scenario and damage category. This advantage resulted from the significantly higher coefficient of performance of the IREC system. The amounts of cooling energy generated and electricity consumption were determined based on temperature and relative humidity data recorded at hourly intervals in the summer seasons of 2023 and 2024. The operation turned out to be a life cycle stage with dominating environmental load. The uncertainty analysis carried out with Monte Carlo simulations indicated significant deviation, particularly for the ecosystem category. The sensitivity analysis showed that the assumed electricity mix did not significantly affect the general conclusions.
Journal Article
Review of Evaporative Cooling Systems for Buildings in Hot and Dry Climates
Evaporative cooling systems have gained increasing attention as an energy-efficient solution for climate control in hot and dry regions. This review aims to assess the effectiveness of the most recent advancements in evaporative cooling technologies for building applications in hot and dry climates. The review focuses on global literature, with an emphasis on building applications. The findings of this review indicate that evaporative cooling systems with hybrid configurations, particularly multi-stage systems, can achieve cooling efficiencies of up to 95%. These systems are highly energy-efficient, with energy consumption ranging from 0.3 to 1.2 kW/t, with hybrid and multi-stage designs showing the best performance. Direct and indirect evaporative cooling systems also perform well, with cooling effectiveness ranging from 60% to 85%. Their reliance on water, rather than harmful refrigerants, results in minimal environmental impact, making them an eco-friendly alternative to traditional cooling methods. The coefficient of performance (COP) for these systems is favorable, with hybrid and multi-stage designs reaching COP values as high as 35, indicating substantial cooling output relative to energy input. In addition, the performance of evaporative cooling systems is highly influenced by their design parameters and operating conditions. Advanced designs that incorporate multi-stage cooling and effective water management tend to provide enhanced cooling capacity and energy efficiency. Therefore, evaporative cooling systems are an excellent option for sustainable building practices, contributing significantly to energy savings and reduced environmental impact.
Journal Article