AN ALTERNATIVE HYBRID DESICCANT-COMPRESSION SYSTEM FOR AIR CONDITIONING APPLICCATIONS WITH FULL AIR RENOVATION

2020 ◽  
Author(s):  
Carlos Eduardo Leme Nobrega
Keyword(s):  
Air Conditioning ◽  
Compression System

scholarly journals Hybrid Adsorption-Compression Systems for Air Conditioning in Efficient Buildings: Design through Validated Dynamic Models

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1161 ◽  
Author(s):  
Valeria Palomba ◽  
Efstratios Varvagiannis ◽  
Sotirios Karellas ◽  
Andrea Frazzica
Keyword(s):  
Air Conditioning ◽  
Dynamic Models ◽  
Integrated Model ◽  
Commercial Software ◽  
Renewable Sources ◽  
Compression System ◽  
Intrinsic Complexity ◽  
Main Components ◽  
Vapour Compression

Hybrid sorption-compression systems are gaining interest for heating/cooling/ refrigeration purposes in different applications, since they allow exploiting the benefits of both technologies and a better utilization of renewable sources. However, design of such components is still difficult, due to the intrinsic complexity of the systems and the lack of reliable models. In particular, the combination of adsorption-compression cascade unit has not been widely explored yet and there are no simulations or sizing tools reported in the literature. In this context, the present paper describes a model of a hybrid adsorption-compression system, realised in Modelica language using the commercial software Dymola. The models of the main components of the sorption and vapour compression unit are described in details and their validation presented. In addition, the integrated model is used for proving the feasibility of the system under dynamic realistic conditions and an example of the technical sizing that the model is able to accomplish is given.

scholarly journals Analysis of supplemental dehumidification for increased energy efficiency of shoulder seasons based on climate change predictions in Austin Texas

2021 ◽  
Vol 2042 (1) ◽  
pp. 012182
Author(s):  
B Marshall ◽  
J Felkner ◽  
Z Nagy
Keyword(s):  
Climate Change ◽  
Energy Efficiency ◽  
Potential Energy ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Energy Savings ◽  
Vapor Compression ◽  
Compression System ◽  
Vapor Compression System ◽  
American Society

Abstract This research project compared a standard vapor compression system and a standard desiccant dehumidification system with heat wheel to determine if there was some potential energy savings for “shoulder season” hours in Austin Texas. “Shoulder season” hours as defined in the paper are hours during which the dry bulb temperature falls within the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) comfort bound but the humidity is above the comfortable humidity point. These hours are normally addressed with vapor compression systems which dehumidify by cooling the air under the comfort setpoint to dehumidify, which is wasteful of energy. The study found that for these shoulder season hours a desiccant dehumidification system was around 4.5 times more energy efficient at reaching comfort setpoints if free heating was used for drying the desiccant.

scholarly journals TEST CHARACTERISTICS OF CENTRIFUGAL PUMPS ON COOLING HYDRONIC SYSTEM USING ENVIRONMENTAL FRIENDLY REFRIGERATION

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Yudhy Kurniawan ◽  
Kusnandar Kusnandar
Keyword(s):  
Air Conditioning ◽  
Large Scale ◽  
Cold Water ◽  
Cooling Capacity ◽  
Water Tank ◽  
Centrifugal Pumps ◽  
Practice Test ◽  
Compression System ◽  
In Series ◽  
Vapour Compression

In generally cooling hydronic system applied to large-scale commercial or industrial use, where water cooling is processed through heat transfer mechanism in the evaporator pipe using a vapour compression system such as a chiller with refrigerant. The research idea is based on not available practice test of cooling hydronic system at the Department of Refrigeration and Air Conditioning Engineering at State Polytechnic of Indramayu which is the main competency in the course of Air Conditioning Applied. As teh utilization practice made cooling hydronic system by utilizing a vapour compression system that is split AC using refrijeran R32 is environmentally friendly. The split AC system modifies its evaporator coil into a heat exchange medium to cool water in the water tank. The cold water is then distributed in the piping installation system with the two pumps that are varied in series and parallel. From this process, it is necessary to know the working capability of the pumps in terms of its characteristics (head and capacity) or its performance, including energy losses and cooling capacity system. The results obtained are analyzed and the calculation is in accordance with theoretically known study.

scholarly journals Thermodynamic Analysis of Hybrid Absorption Compression System

2018 ◽  
Vol 7 (3.34) ◽  
pp. 445
Author(s):  
A Ramesh kumar ◽  
. .
Keyword(s):  
Virtual Reality ◽  
Thermodynamic Analysis ◽  
Air Conditioning ◽  
Thermal Conditions ◽  
Working Fluid ◽  
Exergy Destruction ◽  
Exergetic Efficiency ◽  
Compression System ◽  
Realistic Image ◽  
Hybrid Cycle

The Virtual Reality realistic image content is a technology to enable building imaginary space by This paper presents thermodynamic  studies conducted on a GAX hybrid  absorption-compression (HYBRID) cycle using ammonia-water as working fluid for air-conditioning applications. The effect of generator, condenser and absorber temperatures on exergy destruction has been investigated. The effect of absorber pressure on the exergy destruction of the cycle has also been studied. It is found that generator and absorber are the major contributors in the total exergy destruction of the hybrid cycle. Comparison of hybrid cycle with conventional GAX cycle shows hybrid cycle has lower value of exergy destruction than the conventional GAX cycle. It is also found that at same thermal conditions assumed in this work the hybrid cycle gives 18 percent increases in average exergetic efficiency when compared to the conventional GAX cycle.   

Influence of trees on the energy consumption of a social housing in mid-western Brazil

2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Computational Simulation ◽  
Building Energy ◽  
General Idea ◽  
Heat Island ◽  
Study Region ◽  
Ample Evidence

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.

Perancangan Pengkondisian Udara pada Ruangan Steril Rumah Sakit Mitra Medika dengan Standard Cleanroom Menggunakan Instalasi Ducting

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Fremmy Raymond Agustinus
Keyword(s):  
Air Conditioning ◽  
Static Pressure ◽  
Filter Medium ◽  
Positive Pressure ◽  
Design Tools ◽  
Microsoft Excel ◽  
Cooling Unit ◽  
X 24 ◽  
Air Passage ◽  
Booster Fan

Desain penyejuk udara juga dapat diterapkan di bidang kesehatan, dengan standar Cleanroom dapat diperoleh suhu, kelembaban, kenyamanan dan kebersihan yang dibutuhkan untuk ruang steril (ruang bedah). Perancangan pendingin udara dalam hal ini dilakukan dengan menentukan beban pendinginan yang diperlukan untuk ruang steril (ruang bedah), kemudian menentukan ukuran ducting, jalur ducting, dan jumlah penggunaan ducting. Desain ini menggabungkan unit split saluran yang dimodifikasi, kipas booster, filter pra, filter medium, dan filter HEPA dengan menggunakan saluran aluminium preinsulated sebagai saluran udara. Desain dilakukan dengan menggunakan perangkat lunak AutoCAD 2012, Design Tools Duct Sizer, dan Microsoft Excel. Dari hasil perhitungan dan desain didapatkan kebutuhan kapasitas 3 ruang bedah yaitu ducted ducted 100.000 BTUH sebanyak 3 unit, booster fan 3.3 - 4 Di WG sebanyak 3 unit, pre filter 24 "x 24" x 2 "6 set, filter menengah 610 x 610 x 290 mm 6 set, dan filter HEPA 1220 x 610 x 70 mm 12. Untuk ruang steril, tekanan statis yang dihasilkan oleh unit pendingin harus lebih besar daripada tekanan statis yang dihasilkan dari unit yang ada. di ruang semi steril. Dengan kata lain, ruang steril harus memiliki tekanan positif terhadap ruang semi steril. Hal ini dimaksudkan agar udara di ruang semi steril tidak masuk ke ruang steril ketika pintu antar ruangan dibuka. Desain dan perhitungan ruang bedah, suhu nyata yang diperoleh adalah 23 ° C ± 2 ° C dan kelembaban relatif yang diperoleh adalah 60% ± 2%.   Air conditioning design can also be applied in the health field, with cleanroom standard can be obtained temperature, humidity, comfort and hygiene needed for sterile room (surgical room). The design of air conditioning in this case is done by determining the cooling load required for the sterile room (surgical room), then determining the ducting size, ducting path, and the amount of ducting usage. This design combines modified ducted split unit, booster fan, pre filter, medium filter, and HEPA filter by using preinsulated aluminum duct as an air passage. The design is done by using AutoCAD 2012 software, Design Tools Duct Sizer, and Microsoft Excel. From the calculation and design result obtained the capacity requirement of 3 surgical room that is split ducted 100.000 BTUH as many as 3 units, booster fan 3.3 - 4 In WG as many as 3 units, pre filter 24"x 24" x 2" 6 sets, medium filter 610 x 610 x 290 mm 6 sets, and HEPA filter 1220 x 610 x 70 mm 12 sets. For the sterile room, the static pressure generated by the cooling unit shall be larger than the static pressure generated from the unit present in the semi sterile room. In other words, the sterile room must have positive pressure to the semi sterile room. It is intended that the air in the semi sterile room does not enter into the sterile room when the door between room opened. In this surgical room design and calculation, real temperature obtained is 23 °C ± 2 °C and the relative moisture obtained is 60% ± 2%.

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