The increase of occupant comfort demands are leading to rising requirement for air conditioning, but deteriorating global energy and environment crisis are starving for energy saving and environmental protection. The need to come up with the new energy saving as well as environmental friendly air conditioning systems has been more urgent than ever before. In hot and humid areas, the liquid desiccant air-conditioning systems based on evaporative cooling was proposed as a promising invention.
This system overcomes the difficulty of evaporative cooler increased humidity with cooling, which makes it unsuitable for hot and humid climates, by dehumidifying the air first and then cooling it inside an evaporative cooler with water. The heating effect of dehumidification process is compensated by cooling water circulation. The use of dehumidifier in conjunction with an evaporative cooler increases the efficiency of the system. Some of the advantages of using this system are: it can remove the air latent load, environmental friendly, removes the pollutants from the process air and reduces the amount of the electrical energy consumed.
The primary objective of this project is to design a solar based liquid desiccant evaporative system to purify and supply cool air. Liquid desiccant dehumidification has been proven to be an effective method to extract the moisture of air with relatively less energy consumption, especially compared with conventional vapor compression system. Inside the dehumidifier we used calcium chloride solution which after some period of time gets diluted with water and loses its moisture absorbing capacity and therefore, needs to be heated in the solar collector to ensure that the liquid desiccant does not lose its absorption capacity.
In this project, several different aspects in solar assisted liquid desiccant based evaporative cooler have been considered. Some of these aspects include the availability of the materials, manufacturability of the product, sustainability of the product, health and safety regulations and the environmental effects of the product.
Table of Contents
CHAPTER 1 - INTRODUCTION
1.1. Detailed definition of the project
1.1.1 Conventional Evaporative Cooling Systems
1.1.2 Desiccant Material
1.1.3 Different Type of Desiccants
1.1.4 Desiccant Cooling System
1.1.5 Desiccant Dehumidification
1.1.6 Desiccant Based Evaporative Cooling
1.2. Significance of the project
1.3. Detailed project objectives
1.4. Detailed project constraints
1.5. Report Organization
CHAPTER 2 - LITERATURE REVIEW
2.1. Background information
2.1.1 Liquid Desiccant Dehumidification for Solar Cooling
2.1.2 Hybrid Solar Liquid desiccant and Evaporative Cooling Systems
2.2. Concurrent solutions
2.3. Comparisons of the concurrent solutions
2.4. Engineering standards of the concurrent solutions
CHAPTER 3 -DESIGN and ANALYSIS
3.1. Proposed/Selected design
3.2. Engineering standards
3.3. Design calculations
3.3.1 Solar Collector
3.3.2 Desiccant Dehumidifier
3.3.3 Pump Calculations
3.3.4 Evaporative Cooler
3.4. Cost analysis
CHAPTER 4 – MANUFACTURING PLAN
4.1. Manufacturing process selection
4.1.1 Material Selection
4.1.2 Cost of the Manufacturing Process
4.1.3 Properties and characteristics of product
4.2. Detailed manufacturing process
CHAPTER 5 - PRODUCT TESTING PLAN
5.1. Verification plan of the objectives of the project
Project Objectives and Focus Areas
The primary objective of this project is to design and develop a solar-based liquid desiccant evaporative cooling system. The work aims to address the limitations of conventional evaporative cooling in hot and humid climates by implementing a dehumidification stage using a calcium chloride salt solution, which is regenerated using solar thermal energy to ensure efficiency and sustainability.
- Design and development of a desiccant-enhanced evaporative cooling unit.
- Moisture removal from ambient air using liquid calcium chloride desiccant.
- Implementation of solar thermal energy for desiccant regeneration.
- Analysis of system performance, energy consumption, and environmental impact.
- Verification of design through engineering standards and manufacturing plans.
Excerpt from the Book
Desiccant Based Evaporative Cooling
In general, evaporative cooling systems are used when the wet blub temperature does not rise beyond 25 ˚C usually. In dry climatic conditions the high coefficient of performance (COP) and evaporative cooling units can operate and because of the air saturation of the surrounding air in moisture climates the effectiveness of these cooling units decreases. On the basis of this we can say that the partnership of evaporative cooler with desiccant dehumidifier is best and by this the elimination of moisture is possible from the air steam and so the function of these cooling units can be proven very effective. The dehumidifier contains desiccant material, the purpose of that material is to absorb or remove moisture from the moist air. These materials have the ability to absorb or adsorb so these materials absorb or adsorb and hold water vapor from the humid air. The evaporative desiccant system is the combination of the following units:
• desiccant dehumidifier unit
• regenerator unit
• cooling unit
The basic operation of a desiccant evaporative system with a solar collector or thermal collector is shown in Fig 13.
Summary of Chapters
CHAPTER 1 - INTRODUCTION: This chapter provides the general information about the project, including the importance of the desiccant-enhanced evaporative system, its working principle, and the use of solar energy for regeneration.
CHAPTER 2 - LITERATURE REVIEW: This chapter covers the background information and literature review, mentioning various concurrent solutions and comparisons between them along with relevant engineering standards.
CHAPTER 3 -DESIGN and ANALYSIS: This chapter describes the proposed design using Solidworks and includes assumption-based calculations for the desiccant, pump, solar collector, and cost analysis.
CHAPTER 4 – MANUFACTURING PLAN: This chapter lists the components used in detail and provides the selection process for materials and manufacturing methods.
CHAPTER 5 - PRODUCT TESTING PLAN: This chapter discusses the verification plan of the project objectives and the application of engineering standards.
Keywords
Evaporative Cooling, Liquid Desiccant, Calcium Chloride, Solar Thermal Collector, Dehumidification, Air Conditioning, Energy Efficiency, Sustainable Cooling, Humidity Control, Thermal Energy, HVAC, Desiccant Regeneration, Mass Transfer, COP, Mechanical Engineering.
Frequently Asked Questions
What is the core focus of this research?
The work focuses on designing a sustainable and energy-efficient air conditioning system that combines liquid desiccant dehumidification with evaporative cooling, powered by solar energy to overcome the limitations of standard cooling systems in humid environments.
What are the primary thematic fields covered in this study?
The study covers thermodynamics, psychrometrics, solar energy application, mechanical design, material selection, and manufacturing processes within the context of HVAC systems.
What is the ultimate goal of the project?
The primary goal is to successfully design and model an evaporative cooling system that reduces air temperature and humidity effectively, using solar energy for the regeneration of the desiccant solution to provide a viable alternative to conventional vapor compression systems.
Which scientific methods were applied in this work?
The project employs mathematical modeling, psychrometric analysis for determining moisture removal rates, and theoretical performance calculations for the solar collector and pump systems, validated through engineering standards.
What topics are discussed in the main body of the report?
The main body covers the detailed design of the system, literature reviews of current solutions, step-by-step design calculations for components like the solar collector and dehumidifier, and a comprehensive manufacturing and testing plan.
What are the characterizing keywords of this project?
The work is best characterized by terms such as Liquid Desiccant, Solar Thermal Energy, Evaporative Cooling, Calcium Chloride, HVAC, and Sustainable Engineering.
How does the calcium chloride solution contribute to the cooling process?
The calcium chloride solution acts as a liquid desiccant that extracts moisture from the incoming air stream, which allows the subsequent evaporative cooling stage to operate more effectively without increasing the humidity of the output air.
Why is the solar collector integral to this design?
The solar collector provides the heat energy required to evaporate excess moisture from the diluted desiccant solution, thereby regenerating it so it can continue to absorb moisture from the air, maintaining a constant system efficiency.
- Arbeit zitieren
- Zaeem Ahmer (Autor:in), Muhammad Hassan Saeed (Autor:in), Saad Elahi (Autor:in), Hassan Elghazali (Autor:in), Munther Mouzaneh (Autor:in), 2017, Design of a Solar assisted Liquid Desiccant based evaporative Cooler, München, GRIN Verlag, https://www.hausarbeiten.de/document/385089
