Liquid Desiccants Applications in Cooling and Dehumidification – An Overview

2019 ◽  
pp. 1-17
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Fossil Fuel ◽  
Electrical Energy ◽  
Cooling Load ◽  
Vapor Compression ◽  
Vapor Compression System ◽  
Industrial Use ◽  
Optimum Cost ◽  
Effective Use

Potential option to replace the traditionally used vapor compression system with desiccant based dehumidification and cooling to overcome the problems in VCR use like as substantial consumption of high grade electrical energy and to eliminate the use of the CFC based refrigerants which are responsible for the depletion of ozone layer. The desiccant cooling can be proved to be an efficient in highly moist atmosphere to handles the latent cooling load of the conditioned space. The present overview explains about the detailed ideas for making use of various chemicals as the desiccant solution for their optimum cost and characteristics. The desiccant cooling can handle both humidity and temperature separately and effectively to produce necessary thermal comfort within the conditioned space. The desiccant cooling can find optimum use of renewable solar energy in air conditioning by applying them for desiccant regeneration to lower the consumption of electricity which produced mostly by fossil fuel based power plants which leads to problem of pollution subsequently. The present review provides the direction for effective use of the desiccant based cooling for separable control over temperature and humidity in case of both residential and industrial use to ameliorate the dual - energy and cost saving.

scholarly journals Liquid Desiccants Applications in Cooling and Dehumidification – An Overview

2019 ◽  
pp. 1-17
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Fossil Fuel ◽  
Electrical Energy ◽  
Cooling Load ◽  
Vapor Compression ◽  
Vapor Compression System ◽  
Industrial Use ◽  
Optimum Cost ◽  
Effective Use

Potential option to replace the traditionally used vapor compression system with desiccant based dehumidification and cooling to overcome the problems in VCR use like as substantial consumption of high grade electrical energy and to eliminate the use of the CFC based refrigerants which are responsible for the depletion of ozone layer. The desiccant cooling can be proved to be an efficient in highly moist atmosphere to handles the latent cooling load of the conditioned space. The present overview explains about the detailed ideas for making use of various chemicals as the desiccant solution for their optimum cost and characteristics. The desiccant cooling can handle both humidity and temperature separately and effectively to produce necessary thermal comfort within the conditioned space. The desiccant cooling can find optimum use of renewable solar energy in air conditioning by applying them for desiccant regeneration to lower the consumption of electricity which produced mostly by fossil fuel based power plants which leads to problem of pollution subsequently. The present review provides the direction for effective use of the desiccant based cooling for separable control over temperature and humidity in case of both residential and industrial use to ameliorate the dual - energy and cost saving.

scholarly journals Analysis Of The Coefficien Of Performance (COP) Freezer Produced By Solar Cell

2021 ◽  
Vol 2 (6) ◽  
pp. 2230-2238
Author(s):  
Sudirman Lubis ◽  
Rafsanzani Pane
Keyword(s):  
Solar Energy ◽  
Electric Energy ◽  
Electrical Energy ◽  
Energy Sources ◽  
Cooling Load ◽  
Vapor Compression ◽  
The Future ◽  
Vapor Compression System ◽  
The Media ◽  
The University

The use of freezer machines has now become a necessity for the wider community, because it is very helpful for humans in everyday life. The cooling load given greatly affects the performance of the freezer, both in terms of electrical energy consumption and the ability to increase system usage time. The greater the cooling load will increase the use of electrical energy during operation. This is very worrying in the future where the issue of depleting fossil energy sources which is currently a priority for producing electrical energy is increasing and filling the media. In recent years, solar energy has been rumored to be the answer to this problem. Where heat energy from the sun is used to move protons and electrons in a solar panel media to produce electrical energy that can be used for the needs of many people. This has become the attraction of researchers to make an innovation in the use of solar energy in a freezer system. Judging from the research roadmap related to solar energy and the vapor compression system in the freezer that was launched in the last few years, not many innovations have been carried out in the use of energy sources. The cooling load to be used will be adjusted to the capacity of the energy source used, which is 410 WP. With the capacity of the freezer that is used with a power of 1/4 PK which will increase its ability/ efficiency to be used and replace the paid electric energy freezer. This is expected to be useful for the public and contribute knowledge and help realize the university roadmap in the future.

Influence of Façade Area on Thermal Performance of Building for Cooling Purposes

2018 ◽  
Author(s):  
Hamad H. Almutairi ◽  
Abdulrahman Almutairi ◽  
Jaber H. Almutairi
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Electrical Power ◽  
Electrical Energy ◽  
Building Design ◽  
Renewable Energy Resources ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Simulation Engine ◽  
Hot Climate

Buildings account for significant energy consumption worldwide particularly in regions where energy patterns influenced primarily by weather. Air conditioning system became an essential evaluation factor during building design and construction. The level of curiosity about air conditioning system efficiency in terms of energy usage is increasing quickly. In Kuwait; which is a hot climate country; air conditioners account for 70% of total electrical power. Electricity in Kuwait is produced entirely by the non-renewable energy resources. This work aims to assess the potential electrical savings that could be acquired by reducing building’s façade area towards East-West directional orientation in Kuwait. For this purpose, a detached building model with uniform geometry; was simulated by Energy Plus Thermal Simulation Engine through its interface with DesignBuilder software. Two cases were developed for the analysis; both have the same simulation inputs. The only difference was the orientation of the facades. The results show a reduction of about 900 kWh cooling annually if the largest facades were positioned towards north and south. The obtained saving in annual basis is attributed to about 420 kWh electrical power. Equivalent CO2 emissions associated with the saved electrical energy from power plants in Kuwait were estimated. The resulted savings are promising for early decision making for prospective buildings to be built in future.

scholarly journals Progressive Development and Challenges Faced by Solar Rotary Desiccant-Based Air-Conditioning Systems: A Review

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1785
Author(s):  
Ranjan Pratap Singh ◽  
Ranadip K. Das
Keyword(s):  
Solar Energy ◽  
Air Conditioning ◽  
Energy Use ◽  
Operating Cost ◽  
Electrical Energy ◽  
Low Grade ◽  
Vapor Compression ◽  
Cooling Systems ◽  
Ongoing Research ◽  
Air Conditioning Systems

A rotary desiccant-based air-conditioning system is a heat-driven hybrid system which combines different technologies such as desiccant dehumidification, evaporative cooling, refrigeration, and regeneration. This system has an opportunity to utilize low-grade thermal energy obtained from the sun or other sources. In this paper, the basic principles and recent research developments related to rotary desiccant-based cooling systems are recalled and their applications and importance are summarized. It is shown that with novel system configurations and new desiccant materials, there is great potential for improving the performance and consistency of rotary desiccant systems; at the same time, the use of solar energy for regeneration purposes can minimize the operating cost to a great extent. Some examples are presented to demonstrate how rotary desiccant air conditioning can be a promising solution for replacing traditional vapor-compression air-conditioning systems. Recent advances and ongoing research related to solar-powered hybrid rotary desiccant cooling systems are also summarized. The hybrid systems make use of a vapor-compression system in order to have better operational flexibility. These systems, although they consume electrical energy, use solar energy as the principal source of energy, and hence, significant savings of premium energy can be obtained compared to conventional vapor-compression systems. However, further research and development are required in order to realize the sustainable operation of solar rotary desiccant air-conditioning systems, as solar energy is not steady. Reductions in capital cost and size, along with improvements in efficiency and reliability of the system is still needed for it to become a player in the market of air conditioning.

An Analytical Comparison of Adsorption and Vapor Compression Air Conditioners for Electric Vehicle Applications

1996 ◽  
Vol 118 (1) ◽  
pp. 16-21 ◽  
Author(s):  
S. M. Aceves
Keyword(s):  
Electric Vehicle ◽  
Air Conditioning ◽  
Cooling System ◽  
Cooling Load ◽  
Air Conditioner ◽  
Vapor Compression ◽  
Adsorption System ◽  
Air Conditioners ◽  
Driving Cycles ◽  
Adsorption Systems

This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the overall system weight, which includes the cooling system weight and the weight of the battery necessary to provide energy for air conditioner operation. The system with the minimum overall weight is considered to be the best. The results show the optimum values of all the variables, as well as temperatures and amounts adsorbed, for the adsorption and desorption processes. The results indicate that, for the conditions analyzed in this paper, vapor compression air conditioners are superior to adsorption systems, not only because they are lighter, but also because they have a higher COP and are more compact.

Iterative Modeling and Identification of a CO2 Air Conditioning System

2004 ◽  
Author(s):  
Bryan P. Rasmussen ◽  
Andrew Alleyne ◽  
Andrew Musser
Keyword(s):  
System Identification ◽  
First Principles ◽  
Air Conditioning ◽  
Linear Models ◽  
Mimo System ◽  
Vapor Compression ◽  
Minimal Representation ◽  
Air Conditioning System ◽  
Vapor Compression System ◽  
Identification Techniques

This paper uses an air conditioning system to illustrate the benefits of iteratively combining first principles and system identification techniques to develop control-oriented models of complex systems. A transcritical vapor compression system is initially modeled with first principles and then verified with experimental data. Both SISO and MIMO system identification techniques are then used to construct locally linear models. Motivated by the ability to capture the salient dynamic characteristics with low order identified models, the physical model is evaluated for essentially nonminimal dynamics. A singular perturbation model reduction approach is then applied to obtain a minimal representation of the dynamics more suitable for control design, and yielding insight to the underlying system dynamics previously unavailable in the literature. The results demonstrate that iteratively modeling a complex system with first principles and system identification techniques gives greater confidence in the first principles model, and better understanding of the underlying physical dynamics. Although this iterative process requires more time and effort, significant insight and model improvements can be realized.

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.

Performance Prediction of Electroosmotic Dehumidification

2009 ◽  
Author(s):  
David W. Gerlach
Keyword(s):  
Air Conditioning ◽  
Airflow Rate ◽  
Air Conditioner ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
Vapor Compression Cycle ◽  
Compression Cycle ◽  
In Series ◽  
Vapor Compression System ◽  
Air Conditioning Systems

In electroosmotic dehumidification (EOD), a membrane composed of a desiccant material removes moisture from air to be conditioned. Then the water is pumped through pores in the membrane by the application of a voltage and rejected on the other side. This allows the sensible and latent loads in air conditioning to be handled separately and may lead to improvements in energy efficiency and comfort control. The performance of an air conditioning system using an electroosmotic dehumidification system in series with a conventional vapor compression cycle was modeled. The electroosmotic system handles the entire latent load and the vapor compression system handles the entire sensible cooling load. Performance of the system was compared to a conventional vapor compression air conditioner that handles both the latent and sensible loads with a single evaporator coil. Literature data for Nafion membranes was used in a simple electroosmotic drag model. Modeling indicates the feasibility of electroosmotic dehumidification for separating the control of latent and sensible load in air conditioning systems. The total COP of the system, neglecting fan power, can be 1–2 times higher (depending on airflow rate) than a system using an evaporator for latent and sensible load.

Retrofitting R-22 Split Type Air Conditioning with Hydrocarbon (HCR-22) Refrigerant

2013 ◽  
Vol 388 ◽  
pp. 91-95 ◽  
Author(s):  
Henry Nasution ◽  
Abdul Latiff Zulkarnain ◽  
Azhar Abdul Aziz ◽  
Mohd Rozi Mohd Perang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Room Temperature ◽  
Internal Heat ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Refrigeration System ◽  
Electrical Energy Consumption ◽  
The One

An experimental study to evaluate the energy consumption of a split type air conditioning is presented. The compressor works with the fluids R-22 and HCR-22 and has been tested varying the internal heat load 0, 500, 700 and 1000 W. The measurements taken during the one hour experimental periods at 10-minutes interval times for temperature setpoint of 20oC. The performance data considered where the evaporator cooling load, the condenser heat rejection, the electrical energy consumption, the refrigeration system temperatures, and the room temperature. And hence the Coefficient of Performance (COP) could be determined. The final results of this study show an overall better energy consumption of the HFC-22 compared with the R-22.

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