A Review of Desiccant Cooling Systems

1993 ◽  
Vol 115 (1) ◽  
pp. 1-8 ◽  
Author(s):  
D. G. Waugaman ◽  
A. Kini ◽  
C. F. Kettleborough

This paper describes recent published design advances that have been made in desiccant cooling systems. In desiccant cooling cycles, the desiccant reduces the humidity of the air by removing moisture from the air. Then the temperature is reduced by other components such as heat exchangers, evaporative coolers, or conventional cooling coils. The main advantage that desiccant cooling systems offer is the capability of using low-grade thermal energy. Desiccant cooling systems for residential and commercial applications are now being used to reduce energy-operating costs. However, the initial costs are comparatively high. The focus of research for the past decade has been to develop desiccant systems with a high coefficient of performance. Recent studies have emphasized computer modeling and hybrid systems that combine desiccant dehumidifiers with conventional systems.

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Rofan Aziz ◽  
Muh Tanwirul Afkar ◽  
Sunanto Sunanto ◽  
Karsid Karsid

Conventional cooling systems based on vapor compression have a high coefficient of performance (COP). However shortage of vapor compression cooling systems still using refrigerants that have detrimental effects on the environment. For that purpose, the research of fruit and vegetable storage machine using thermoelectric system TEC1-12706 with temperature control system using arduino. In this study the temperature in the cabin can be stable at 15° C and still feasible for use as a storage of fruits and vegetables.


2020 ◽  
Vol 38 (6) ◽  
pp. 2521-2540
Author(s):  
Juliana Isabel Saucedo Velázquez ◽  
Wilfrido Rivera Gómez Franco ◽  
Efraín Gómez-Arias ◽  
Geydy Gutiérrez Urueta

Conventional cooling systems consume a high percentage of the world’s total electricity generation. Because absorption cooling systems can be mainly operated with thermal energy, they can be used to reduce such percentage. In the present paper, an analysis is carried out to determine the cooling potential that can be obtained from a geothermal well in a location of Mexico by using a single-stage absorption cooling system. The analysis has been carried out taking into account the desired cooling temperature, the ambient temperature, and the temperatures at different depths of the wells for a typical day of every season of the year. The results showed that, for a fixed generation temperature, a maximum cooling potential as big as 71,594 GW, 70,649 GW, 71,164 GW, 70,859 GW could be obtained in Winter, Spring, Summer, and Autumn, respectively. Using the temperatures obtained from the well, for a fixed depth, the results show that higher values are obtained in spring and summer. From the analysis, it is clear that absorption systems operating with geothermal energy could be an excellent alternative to reduce the electricity consumed by conventional systems.


Author(s):  
Anurag Maheswari ◽  
◽  
Manoj Kumar Singh ◽  
Yogesh K. Prajapati ◽  
Niraj Kumar ◽  
...  

Vapor compression refrigeration system (VCRS) based conventional cooling systems run on the high amount of electricity and refrigerants responsible for greenhouse emissions. To save the environment and high-grade energy, traditional cooling systems should be replaced with some environment-friendly alternative. This paper proposed alternative eco-friendly air-conditioning systems based on an amalgam of two different technologies, i.e., desiccant dehumidification and thermoelectric (TE) cooling. The proposed air-conditioning system has the following subprocess: dehumidification of moist air by the solid desiccant wheel, cooling of processed air by TE modules, and regeneration of desiccant wheel by an electric heater and waste heat from TE modules. The air conditioning system has been experimentally studied for cooling performance, cooling effect, and energy input. The maximum coefficient of performance of 0.865 can be achieved with the proposed system, and it can be used for cooling effects up to 1442.24 W to maintain the human comfort condition in the chamber i.e. approximately 22 ℃ and RH 50% defined by ASHRAE.


1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.


Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.


Author(s):  
John Hunsley ◽  
Eric J. Mash

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.


2021 ◽  
pp. 088506662199232
Author(s):  
Xiaojuan Zhang ◽  
Xin Li

Septic shock with multiple organ failure is a devastating situation in clinical settings. Through the past decades, much progress has been made in the management of sepsis and its underlying pathogenesis, but a highly effective therapeutic has not been developed. Recently, macromolecules such as histones have been targeted in the treatment of sepsis. Histones primarily function as chromosomal organizers to pack DNA and regulate its transcription through epigenetic mechanisms. However, a growing body of research has shown that histone family members can also exert cellular toxicity once they relocate from the nucleus into the extracellular space. Heparin, a commonly used anti-coagulant, has been shown to possess life-saving capabilities for septic patients, but the potential interplay between heparin and extracellular histones has not been investigated. In this review, we summarize the pathogenic roles of extracellular histones and the therapeutic roles of heparin in the development and management of sepsis and septic shock.


Author(s):  
Rhys-Sheffer Birthwright ◽  
Achille Messac ◽  
Timothy Harren-Lewis ◽  
Sirisha Rangavajhala

In this paper, we explore the design of thermoelectric (TE) windows for applications in building structures. Thermoelectric windows are equipped with TE units in the window frame to provide a heat absorption power, given a direct current input. We explore the design performance of the TE window to compensate for its own heat gains. While existing energy efficient windows have made advances towards reducing the heat transfer through them, they still depend on the building’s heating, ventilation and air-conditioning (HVAC) system to compensate for their heat gains. Our research explores the design of a window that can actively compensate for the passive heat flow through the window panes, and to do so with a better coefficient of performance (COP) than conventional HVAC systems. We also optimize the TE window design, and present results of the potential performance for practical applications in the building structure. For the geographic locations considered (Hawaii and Miami), the results are promising. Interestingly, the proposed TE window design actively compensates for the conduction heat gains with a COP greater than three, while that of conventional systems is typically less than three.


1939 ◽  
Vol 17 (2) ◽  
pp. 69-82 ◽  
Author(s):  
D. W. Fenwick

Numerous attempts have been made in the past to induce the eggs of Ascaris suum to hatch outside the body of the host. Extra-corporeal hatching has been observed under a variety of conditions by different workers. Kondo (1920, 1922), Asada (1921) and others record hatching in water, charcoal and sand cultures. Wharton (1915) states that hatching will occur in alkaline digestive juices, while Martin (1913) records a similar phenomenon in pancreatic fluid. Many different explanations have been offered to explain this hatching. Wharton suggested that the interaction of algae and sand might have some effect. Ohba (1923), who found that hatching would occur in 0·2% hydrochloric acid and 0·2% sodium carbonate believed that extra-corporeal hatching was limited to very old cultures of eggs. Many workers are of the opinion that some stimulus normally present in the digestive tract is necessary for hatching.


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