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Advanced Research Journals of Science and Technology

ADVANCED RESEARCH JOURNALS OF SCIENCE AND TECHNOLOGY

(ARJST)

MODELING AND THERMAL ANALYSIS OF AIR-CONDITIONER EVAPORATOR

2349-9027

Hornik 1, Wilk2, 1 Research Scholar, Department of Thermal Engineering,Sian University of Technology,Katowice, Poland.

2 Professor , Department of Thermal Engineering, Sian University of Technology,Katowice, Poland.

Abstract In our project we have modeling an air-cooled evaporator for a home 1.5ton air conditioner. Presently the material used for coils is copper and the material used for fins is copper or aluminum. A 3D model of the evaporator is done in parametric software Pro/Engineer.

To validate the temperatures and other thermal quantities like flux and gradient, thermal analysis is done on the evaporator coil by applying properties copper and suitable material like aluminum. And also we are varying inside cooling fluid Hydrocarbon (HC) and Hydrochloroflourocarbon (HCFC).The best material for the evaporator of our design can be checked by comparing the results.

Thermal analysis is done in ANSYS.

*Corresponding Author:

Refrigerants

Hornik, Research Scholar, Department of Thermal Engineering, Sian University of Technology,Katowice, Poland.

"Freon" is a trade name for a family of haloalkane refrigerants manufactured by DuPont and other companies.

These refrigerants were commonly used due to their superior stability and safety properties. However, these chlorine-bearing refrigerants reach the upper atmosphere when they escape.[6] Once the refrigerant reaches the stratosphere, UV radiation from the Sun cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine atoms catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst unless it binds with another chlorine radical, forming a stable molecule and breaking the chain reaction. The use of CFC as a refrigerant was once common, being used in the refrigerants R-11 and R-12. In most countries the manufacture and use of CFCs has been banned or severely restricted due to concerns about ozone depletion. In light of these environmental concerns, beginning on November 14, 1994, the Environmental Protection Agency has restricted the sale, possession and use of refrigerant to only licensed technicians, per Rules 608 and 609 of the EPA rules and regulations; failure to comply may result in criminal and civil sanctions. Newer and more environmentally-safe refrigerants such as HCFCs (R-22, used in most homes today) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs in turn are being phased out under the Montreal Protocol and replaced by hydro fluorocarbons (HFCs) such as R-410A, which lack chlorine. Carbon dioxide (R-744) is being rapidly adopted as a refrigerant in Europe and Japan. R-744 is an effective refrigerant with a global warming potential of 1. It must use higher compression to produce an equivalent cooling effect.

Published: September 09, 2014 Review Type: peer reviewed Volume: I, Issue : I

Citation: G.Ragni,Research Scholar (2014) MODELING AND THERMAL ANALYSIS OF AIR-CONDITIONER EVAPORATOR

INTRODUCTION TO AIR CONDITIONER An air conditioner (often referred to as AC) is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle. In construction, a complete system of heating, ventilation and air conditioning is referred to as "HVAC". Its purpose, in a building or an automobile, is to provide comfort during either hot or cold weather.

Evaporative coolers A typical home air conditioning unit.

In very dry climates, evaporative coolers, sometimes referred to as swamp coolers or desert coolers, are popular for improving comfort during hot weather. This type of cooler is the dominant cooler used in Iran, which has the largest number of these units of any country in the world,

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Advanced Research Journals of Science and Technology

causing some to refer to these units as "Persian coolers."

An evaporative cooler is a device that draws outside air through a wet pad, such as a large sponge soaked with water. The sensible heat of the incoming air, as measured by a dry bulb thermometer, is reduced. The total heat (sensible heat plus latent heat) of the entering air is unchanged. Some of the sensible heat of the entering air is converted to latent heat by the evaporation of water in the wet cooler pads. If the entering air is dry enough, the results can be quite comfortable; evaporative coolers tend to feel as if they are not working during times of high humidity, when there is not much dry air with which the coolers can work to make the air as cool as possible for dwelling occupants. Unlike air conditioners, evaporative coolers rely on the outside air to be channeled through cooler pads that cool the air before it reaches the inside of a house through its air duct system; this cooled outside air must be allowed to push the warmer air within the house out through an exhaust opening such as an open door or window.

These coolers cost less and are mechanically simple to understand and maintain.

An early type of cooler, using ice for a further effect, was patented by John Gorrie of Apalachicola, Florida in 1842.

He used the device to cool the patients in his malaria hospital.

INTRODUCTION TO EVAPORATOR

INTRODUCTION TO CAD Computer-aided design (CAD), also known as computer-aided design and drafting (CADD), is the use of computer technology for the process of design and designdocumentation. Computer Aided Drafting describes the process of drafting with a computer. CADD software, or environments, provides the user with input-tools for the purpose of streamlining design processes; drafting, documentation, and manufacturing processes. CADD output is often in the form of electronic files for print or machining operations. The development of CADD-based software is in direct correlation with the processes it seeks to economize; industry-based software (construction, manufacturing, etc.) typically uses vector-based (linear) environments whereas graphic-based software utilizes rasterbased (pixilated) environments.

INTRODUCTION TO PRO/ENGINEER Pro/ENGINEER Wildfire is the standard in 3D product design, featuring industry-leading productivity tools that promote best practices in design while ensuring compliance with your industry and company standards. Integrated Pro/ENGINEER CAD/CAM/CAE solutions allow you to design faster than ever, while maximizing innovation and quality to ultimately create exceptional products.

MODEL OF EVAPORATOR

It is in the evaporators where the actual cooling effect takes place in the refrigeration and the air conditioning systems. For many people the evaporator is the main part of the refrigeration system and they consider other parts as less useful. The evaporators are heat exchanger surfaces that transfer the heat from the substance to be cooled to the refrigerant, thus removing the heat from the substance. The evaporators are used for wide variety of diverse applications in refrigeration and air conditioning processes and hence they are available in wide variety of shapes, sizes and designs. They are also classified in different manner depending on the method of feeding the refrigerant, construction of the evaporator, direction of air circulation around the evaporator, application and also the refrigerant control.

In the domestic refrigerators the evaporators are commonly known as the freezers since the ice is made in these compartments. In case of the window and split air conditioners and other air conditioning systems where the evaporator is directly used for cooling the room air, it is called as the cooling coil. In case of large refrigeration plants and central air conditioning plants the evaporator is also known as the chiller since these systems are first used to chill the water, which then produces the cooling effect.

In the evaporator the refrigerant enters at very low pressure and temperature after passing through the expansion valve. This refrigerant absorbs the heat from the substance that is to be cooled so the refrigerant gets heated while the substance gets cooled. Even after cooling the substance the temperature of the refrigerant leaving the evaporator is less the than the substance. The refrigerant leaves the evaporator in vapor state, mostly superheated and is absorbed by the compressor.

INTRODUCTION TO ANSYS ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements.

The software implements equations that govern the behaviour of these elements and solves them all; creating a comprehensive explanation of how the system acts as a whole. These results then can be presented in tabulated or graphical forms. This type of analysis is typically used for the design and optimization of a system far too complex to analyze by hand. Systems that may fit into this category are too complex due to their geometry, scale, or governing equations.

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Advanced Research Journals of Science and Technology

Thermal Analysis of Evaporator using Copper for Tube and Plate – Hydrocarbon Fluid Imported Model from Pro/Engineer

CONCLUSION In our project we have done the modeling for an air-cooled evaporator for 1.5ton air conditioner.

Using 3D Modeling tool Pro/Engineer.

We have performed Thermal analysis on the evaporator by applying tube material as copper and varying the plate materials, Copper, Al99, and Al204. We also did analysis by varying refrigerant Hydrocarbon and Hydro fluorocarbon.

In thermal analysis, we analyze the thermal properties like nodal temperature, thermal gradient and thermal flux.

By observing the results, for hydrocarbon or hydro fluorocarbon, by using plate material Al 204 has more thermal conductivity.

When comparing Hydrocarbon and Hydro fluorocarbon, using Hydro fluorocarbon along with Al 204 is more advantageous since its thermal carectrastrics are better than present using materials.

Meshed Model

References [1] S. Winiewski, The heat loads of piston engines, Publishing house of Transport and Communication, Warsaw, 1972 (in Polish) [2] P. Gustof, Calculations of temperature for all cycle of work in the cylinder of turbo diesel engine, Scientific Journal of Silesian University of Technology: Transport 43 (2001) 5-11 (in Polish).

[3] D. Jdrusik, P. Gustof, The modeling of the heat loads in the exhaust valve from and without regard of the carbon deposit, Journal of KONES 17/3 (2010) 173-179.

[4] D. Jdrusik, P. Gustof, Determines distribution of temperatures the exhaust valve of Diesel in an unsteady state, Scientific Journal of Silesian University of Technology: Transport 50 (2003) 7-14 (in Polish).

Thermal Gradient

[5] P. Gustof, A. Hornik, Modelling of the heat loads of the valves in turbo Diesel engine and the accuracy of calculations, Journal of Achievements in Materials and Manufacturing Engineering 23/2 (2007) 59-62.

AUTHOR Hornik, Research Scholar, Department of Thermal Engineering, Sian University of Technology,Katowice, Poland.

RESULTS Nodal Temperature (C)

Thermal Gradient (K/ mm)

Thermal Flux (W/mm2)

Copper Tube Copper Plate

16

0.658e-11

0.415e-11

Copper Tube Al 99 Plate

16

0.186e-11

0.41e-11

Wilk Professor , Department of Thermal Engineering, Sian University of Technology,Katowice, Poland.

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