1552877066709_mani & Kalyan Project.docx

FABRICATION OF SPLIT AIR CONDITIONER TEST RIG AND DETERMINATION OF COP Submitted in Partial Fulfillment of the Requirement for the Award of Degree of

BACHELOR OF TECHNOLOGY IN MECHANICAL ENGINEERING Submitted by B. MANIKANTA

(15MP1A0334)

E. KALYAN

(15MP1A0312)

S. HEMANTH

(15MP1A0339)

G. SANTHA RAO

(15MP1A0325)

Under the esteemed guidance of

Mr. K. PREMA KUMAR (Associate professor)

DEPARTMENT OF MECHANICAL ENGINEERING SRI SIVANI COLLEGE OF ENGINEERING (Approved by AICTE & Permanently Affiliated to JNTU, Kakinada) CHILAKAPALEM, SRIKAKULAM

2015-2019

SRI SIVANI COLLEGE OF ENGINEERING DEPARTMENT OF MECHANICAL ENGINEERING

CERTIFICATE This is to certify that the project work entitled “FABRICATION OF SPLIT AIR CONDITIONER TEST RIG AND DETERMINATION OF COP” is work of B. MANIKANTA

(15MP1A0334), E. KALYAN (15MP1A0312), S. HEMANTH (15MP1A0339), G. SANTA RAO (15MP1A0325) of IV B.Tech in MECHANICAL ENGINEERING, Sri Sivani College Of Engineering, Affiliated to Jawaharlal Technological University Kakinada during the year 2018-2019 in partial fulfillment of the requirement for the Award of the Bachelor of Technology in Mechanical Engineering.

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Signature of the project guide MR. K. PREMA KUMAR

EXTERNAL EXAMINER

HOD

ACKNOWLEDGEMENT We would like to express sincere gratitude to Mr. K. PREMA KUMAR, Assistant professor of Mechanical Engineering for his guidance and encouragement throughout the project. We greatly appreciate his foresight which enabled us in choosing this project. We are deeply initiated to Mr. B. BALA BHASKAR, head of the department of mechanical engineering, who encouraged us a lot and his guidance and suggestion throughout the project. We would like to thank the principal Dr. B.MURALI KRISHNA, for being helpful and providing us with valuable device and timely guidance. We would like to thank the management of “SRI SIVANI COLLEGE OF ENGINEERING” for providing us with requisite facilities to carry out the project work successful. We would like to thank all the members of Teaching and Non-Teaching staff of Mechanical Department for their support in completion of our project. Our deep thanks to our Friends and Family for their help and support in making our project success.

Sincerely B. MANIKANTA

(15MP1A0334)

E. KALYAN

(15MP1A0312)

S. HEMANTH

(15MP1A0339)

G. SANTHA RAO

(15MP1A0325)

SRI SIVANI COLLEGE OF ENGINEERING (Approved by AICTE & Permanently Affiliated to JNTU, Kakinada) Chilakapalem Village, Srikakulam.

DEPARTMENT OF MECHANICAL ENGINEERING

Institute Vision



To be an institute of eminence, to produce highly skilled, globally competent technocrats.

Institute Mission



Providing high quality, real world, industry relevant, career oriented, professional education to students towards their excellence and growth.



Serving as a centre of technical excellence, creating globally competent, human resources with ethical and moral values.

SRI SIVANI COLLEGE OF ENGINEERING (Approved by AICTE & Permanently Affiliated to JNTU, Kakinada) Chilakapalem Village, Srikakulam.

DEPARTMENT OF MECHANICAL ENGINEERING

Department Vision •

To emerge as a Center of Eminence in Mechanical Engineering to produce quality mechanical engineering graduates who are globally competent with innovation and creativity.

Department Mission •

M1: To provide vibrant learning environment and resources to achieve students’ personal and professional growth.

•

M2: To make rural students professionally skillful and intellectually proficient and promote a sense of excitement among the students in research, design, development and entrepreneurship.

•

M3: To nurture communication skills, leadership, ethics and entrepreneurship among students’ for their sustained growth.

SRI SIVANI COLLEGE OF ENGINEERING (Approved by AICTE & Permanently Affiliated to JNTU, Kakinada) Chilakapalem Village, Srikakulam.

DEPARTMENT OF MECHANICAL ENGINEERING

The graduates of Mechanical Engineering shall:

•

P EO 1 : Preparation: Have acquired new knowledge and expertise through professional development opportunities or advanced education

•

P EO 2 : Core competence: Practice mechanical engineering in a broad range of industries.

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P EO 3 : Breadth: Be engaged in workplace, professional or civic communities

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P EO 4 : Professionalism: Conduct them-selves in a responsible, professional, and ethical manner.

•

P EO 5 : Lifelong learning: Pursue advanced education, research and development, and other creative and innovative efforts in science, engineering, and technology, as well as other professional careers.

SRI SIVANI COLLEGE OF ENGINEERING (Approved by AICTE & Permanently Affiliated to JNTU, Kakinada) Chilakapalem Village, Srikakulam.

DEPARTMENT OF MECHANICAL ENGINEERING

Program Outcomes (POs) and Program Specific Outcomes (PSOs)

PO.1. Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and an engineering specialization to the solution of complex engineering problems.

PO.2. Problem analysis: Identify, formulate, research literature, and analyze complex engineering problems reaching substantiated conclusions using first principles of mathematics, natural sciences, and engineering sciences PO.3. Design/development of solutions: Design solutions for complex engineering problems and design system components or processes that meet the specified needs with appropriate consideration for the public health and safety, and the cultural, societal, and environmental considerations. PO.4. Conduct investigations of complex problems: Use research-based knowledge and research methods including design of experiments, analysis and interpretation of data, and synthesis of the information to provide valid conclusions. PO.5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern engineering and IT tools including prediction and modeling to complex engineering activities with an understanding of the limitations. PO.6. The engineer and society: Apply reasoning informed by the contextual

knowledge to assess societal, health, safety, legal and cultural issues and the consequent responsibilities relevant to the professional engineering practice.

PO.7. Environment and sustainability: Understand the impact of the professional engineering solutions in societal and environmental contexts, and demonstrate the knowledge of, and need for sustainable development. PO.8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of the engineering practice. PO.9. Individual and team work: Function effectively as an individual, and as a member or leader in diverse teams, and in multidisciplinary settings. PO.10. Communication: Communicate effectively on complex engineering activities with the engineering community and with society at large, such as, being able to comprehend and write effective reports and design documentation, make effective presentations, and give and receive clear instructions.

PO.11. Project management and finance: Demonstrate knowledge and understanding of the engineering and management principles and apply these to one’s own work, as a member and leader in a team, to manage projects and in multidisciplinary environments.

PO.12. Life-long learning: Recognize the need for, and have the preparation and ability to engage in independent and life-long learning in the broadest context of technological change. PSO1: Shall have the responsibility of optimum design, development and implement of solutions in view of sustainability and environmental issues. PSO2: Capable of qualifying in national level competitive examinations for successful higher studies and employment.

ABSTRACT A split air conditioner unit consists of Compressor, Condenser, Expansion valve, Evaporator. Refrigerant flows in the vapour compression cycle compressing the refrigerant and rejecting heat in the condenser and again expanding the gas and cooling it and absorbing heat in the evaporator and maintaining the refrigerated space at a desired cooling temperature. The heat from the outdoor unit is rejected into the atmosphere making the heat flow into the atmosphere. Our project idea to calculate the coefficient of performance of split air conditioner by installing pressure gauges, thermocouples, Rotameter at required inlets and outlets. Once our fabrication unit is ready we can use it for experimentation purpose.

CONTENTS CONTENTS CHAPTER 1: INTRODUCTION 1.1 Introduction 1.2 Definition

Chapter2: LITERATURE REVIEW CHAPTER 3: SPLIT AIR CONDITIONER CHAPTER 4: CLASSIFICATION OF SPLIT A/C SYSTEM 4.1 Types of Split A/C systems 4.1.1 Window A/C system 4.1.2 split A/C system 4.1.3 Central A/C system 4.1.4 Packaged A/C system CHAPTER5: COMPONENTS OF SPLIT A/C

5.1 MAIN COMPONENT OF SPLIT A/C 5.1.1 Compressor 5.1.2 Condenser 5.1.3 Expansion Device 5.1.4 Evaporator 5.2EXPERIMENTAL ACCESSORIES 5.2.1 Pressure Gauge 5.2.2 Thermocouple 5.2.3 Energy Meter 5.2.4 Rotameter

CHAPTER6: REFRIGERANTS 6.1 Refrigerant 6.2 Properties of Refrigerant 6.3 Applications APPLICATIONS OF SPLIT A/C P-H DIAGRAM CHAPTER7: TEST RIG OF SPLIT A/C 7.1 What is test rig of Split A/C 7.2 Specifications 7.3 Experimental Set Up 7.4 Procedure DETERMINATION OF C.O.P CHAPTER8: CONCLUSION REFERENCES ANNEXURE

CHAPTER-1 INTRODUCTION Air conditioning is a process of which heats, cools, cleans and circulates air, as well as controlling the moisture content of air. Thus air conditioning makes it possible to change the condition of air in an enclosed space. Before 1992 conditioned air was used to produced items such as candy, Gum, cheese and matches. During 1992 the comfort installation was made in theatres. Since then, almost every major type building has been air conditioned and in the later part of 20th century the applications of air conditioning have been outstanding.

FOR EXAMPLE.     

Computer aided tracking of missiles in military operations Atomic submarines Modern medicines Space explorations Printing and textile industries etc..

W.H Carrier (1876-1950) is known as father of air conditioning. He engineered and installed the first year round A/C system. To bring various groups of engineers together, ASRE (American Society of Refrigeration Engineers)was formed in 1904.

1.2 DEFINITION AND MEANING: Air conditioning is defined as the simultaneous control of temperature, humidity, air circulation and cleanliness of Air with in an enclosed space. Control of temperature implies heating or cooling the air in winter or summer respectively. Control of humidity is increasing moisture content in the air in winter or decreasing the same in summer. Control of air circulation involves the distribution of conditioned air evenly and pleasantly throughout the space at all times. Control of cleanliness involves removal of dust, dirt, soot and any foreign matter by filtering the air that enters the AC plant; ozonate or ionize the conditioned air for elimination of unpleasant smell.

CHAPTER-2 LITERATURE REVIEW Potential Refrigerants for Room Air Conditioner”, 2010 International Symposium on Next-Generation Air Conditioning and Refrigeration Technology, Japan. Aprea, c. and Maiorino, a., “Heat rejection pressure Optimization for a carbon dioxide split system and experimental study”, Applied energy vol. 86, 2009, p23732380. A split system air conditioning prototype operating with CO2 refrigerant, Two compresser stages, and their internal heat exchanger (IHX) was used in this project. At an Evaporating temperature of 5C and gas cooler outlet temperature of 30C with 80 bar operating pressure, the cooling capacity is approximately 3 kW. Air was the heat transfer fluid for the evaporator and the gas coolers. An EVV connected in series with the back pressure value was used as the throttling device to improve evaporator operating when load changes. Optimum pressure level for the gas cooler vs external ambient temperature was determined for ambient temperature of 25, 30, and 35C Cavallini, A., Cecchinato, L., Corradi, M., Formasieri, E., and Zilio, C., “ Two stages transcritical carbon dioxide cycle Optimization: A theoretical and experimental analysis” International Journal of Refrigeration vol. 28, 2005, p.1274-1283.Tests were run with a reciprocating two- stages compressor using CO2 as the refrigerant. The system of equipped with external gas inter cooling between the two compressor status and a backpressure value as the throttling device. The test conditions were chosen in the range of air conditioning applications. evaporator saturation temperature 2.7oc evaporator outlet temperature 8 to10oc, and gas cooler outlet temperature 33oc. The evaporator and gas inter cooler were fin-tube coils with air as external fluid. The result confirmed that an Optimumgas cooler pressure gave maximum COP in the transcritial cycle. The effect of temperature of the secondary fluid in the intercooler was evaluated as well. [cho00] Cho, H., Back, C., and kim, Y., “ performance evolution of Two- Stages CO2 cycle with gas injection in the cooling mode operation”, International Journal of refrigeration, vol.32, 2000, p. 40-46. This study investigated the performance of two - stages CO2 cycle with and without gas injection and with optimal control of EEV opening in a two-stage cycle with gas injection. The test conditions for a comfort cooling application. The refrigerant charge amount, compressor drive frequencies, and EEV opening were varied to determine the optimum conditions for COP and cooling capacity.

CHAPTER-3 SPLIT AIR CONDITIONER Split Air conditioning is the process of removing heat and moisture from the interior of an occupied space, to improve the comfort of occupants. Air conditioning can be used in both domestic and commercial environments. This process is most commonly used to achieve a more comfortable interior environment, typically for humans and other animals; however, air conditioning is also used to cool/dehumidify rooms filled with heat-producing electronic devices, such as computer servers, power amplifiers, and even to display and store some delicate products, such as artwork. Air conditioners often use a fan to distribute the conditioned air to an occupied space such as a building or a car to improve thermal comfort and indoor air quality. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants (chemicals which remove moisture from the air) and subterraneous pipes that can distribute the heated refrigerant to the ground for cooling. In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air humidification, cooling, cleaning, ventilation, or air movement). In common usage, though, "air conditioning" refers to systems which cool air. In construction, a complete system of heating, ventilation, and air conditioning is referred to as HVAC.

3.1 WORKING OF AIR CONDITIONER Conditioners and refrigerators work the same way. Instead of cooling just the small insulated of a refrigeration, an air conditioner cools a room, a whole house or an entire business. Air conditioners use chemicals that easily convert from a gas to a liquid and back again. This chemical is used to transfer heat from the air inside of a home to the outside air. The machine has three main parts, they are a Compressor, a condenser and an evaporator. The compressor and condenser are usually located on the outside air portion of the air conditioner. The evaporator is located on the inside the house. Vapour refrigerant compressed in compressor then passed to the condenser, that vapour refrigerant converts into liquid refrigerant by the condensation. That condensed liquid refrigerant passed to the evaporator through expansion valve, that liquid refrigerant absorbs heat from the room or surroundings in an enclosed space and given cooling. due to absorbed heat, liquid refrigerant converts into vapour and passed to the compressor. Cycle is repeated.

Fig 3.1: Air Conditioning-schematic of systems

CHAPTER-4 CLASSIFICATION OF AIR CONDITIONER SYSTEMS

4.1 TYPES OF A/C SYSTEMS:    

Window A/C systems Split A/C systems Central A/C systems dPackaged A/C systems

4.1.1 WINDOW AIR CODITIONER SYSTEMS: Window air conditioner is sometimes referred as room air conditioner as well. It is the simplest form of an air conditioning system and is mounted on window or walls. It is a single unit that is assembled in a casing where all the components are located. This refrigeration unit has a double shaft fan motor with fans mounted on both sides of the motor .one at the evaporator side and the other at the condenser side The evaporator side is located facing the room for cooling of the space and the condenser side outdoor for the heat rejection. There is an insulated partition separating this two sides within the same casing

Fig: 4.1 Window Air Conditioning System FRONT PANEL: The front panel is the one that is seen by the user from inside the room where it is installed and has a user interfaced control be it electronically or mechanically.

older unit usually are of mechanical control type with rotary knob to control the temperature and fan speed of air conditioner. The newer units come with electronic control system where the functions are controlled using remote control and touch panel wit digital display The front panel has adjustable horizontal and vertical (some models) louvers where the directions of airflow are adjustable to suit the comfort of the users.The fresh intake of air called VENT (ventilation) is provided at the panel in the event that user would like to have a certain amount of fresh air from the outside INDOOR UNIT COMPONENTS: The indoor parts of a window air conditioner include: Cooling coil with a air filter mounted on it. The cooling coil is where the heat exchange happen between the refrigerant in the systems and the air in the room. Fan blower is a centrifugal evaporator blower to discharge the cool air to the room. Capillary Tube is used as an expansion device. It can be noisy during operations if installed too near the evaporator. Operation Panel is used to control the temperature and speed of the blower fan. A thermostat is used to sense the return air temperature and another one to monitor the temperature of the coil. Type of control can be mechanical or electronic type. Drain Pan is used to contain the water that condensate from the cooling coil and is discharged out to the outdoor by gravity. OUTDOOR UNIT COMPONENTS: The outdoor side parts include: Compressor is used to compressor the refrigerant. Condenser coil is used to reject heat from the refrigerant to the outside air. Propeller Fan is used in air cooled condenser to help move the air molecules over the surface of the condensing coil. Fan motor is located here. It has a double shaft where the indoor blower and outdoor propeller fan are connected together. OPERATIONS: During operation, a thermostat is mounted on the return air of the unit. This temperature is used to control the on or off the compressor. Once the room temperature has been achieved, the compressor cutoff.

Usually, it has to be off for at least three minutes before turning on again to prevent it from being damaged for mechanical control type, there is usually a caution to turn on the unit after the unit automatically control the cut-in and cut-off of compressor The evaporator blower fan will suck the air from the room to be conditioned through the air filter and the cooling coil. Air that has been condensed is then discharged to deliver the control and dehumidified air back to the room. This air mixes with the room air to bring down the temperature and humidity level of the room. The introduction of fresh air from the room is done through the damper which is mixed with the return air from the room before passing it over the air filter and the cooling coil. The air filter which is mounted in front of the evaporator acting as a filter to keep the cooling coil clean to obtain good heat transfer from the coil. 4.1.2 SPLIT AIR CONDITIONER SYSTEM: A split air conditioner is a suitable alternative to valve, window, or centralized air conditioner system. Often called mini-split, ductless split, or duct-free air conditioning, this system can adequately cool air standard-sized house without requiring extensive installation cost and efforts. Split air conditioners are home appliances that do not require ductwork, which reduces the energy expenditures. Still, many home owners shy away for split air conditioner system because they do not know how it works or why it is a viable option for a cooling down. The following information will fill you in the function and installation of split air conditioner systems they are un common, but not through any fault or flaw. You may discover that a split system sounds ideal for your home needs. COMPONENTS: A split air conditioner is consists of two units they are indoor and outdoor units. The indoor unit consists of evaporator and blower, outdoor consists of condenser, compressor and expansion valve. Both of these units exists is more common central air units and wall air conditioners. The difference with a mini-split system is that they are separated into two different, distant components, one being outdoors and one being indoors. The two sections are connected with a set of electrical wires and tubing, also called lines, used to transport air between two sections. Its these lines that allow the split AC to be considered ductless and the fact that the wires and tubing are so small and discrete compared to large ducts is where the “mini” split name comes from. FUNCTIONS: The compressor is control by internal thermostat. As the thermostat detects warm air, it activates the outdoor compressor. The compressor circulates a refrigerant gas, increasing the

pressure and temperature of the refrigerant as it compresses it through a series of pipes the refrigerant then moves to the condenser for further processing. In the condenser, a cooling system removes heat from the high pressure gas and the gas changes phase and becomes a liquid. This chilled liquid is passes thorough the tubing indoor until its reaches the evaporator system.

Fig: 4.2 Split Air Conditioner

Inside the home the evaporator fan collects warm air and passes it through a chamber containing the chilled refrigerant. The fan system blows this air, which has been cooled, back into the room, lowering the overall temperature of the space. If the thermostat still defects air that is warmer than desirable, the process continues, and the refrigerant and any access heat that remains in the system are passed back outdoors t the compressor in order to begin the cycle again.

BENFITS OF SPLIT AIR SYSTEMS: Less energy loss: A Split air conditioner is compact and isolated between two localized component section, so there is very little opportunity for heat and other energy to escape the system. Centralized air conditioning systems waste enormous amounts of energy due to heat exchange in the air conditioner duct system. However, the problem is virtually eliminated in a spit air conditioner system. Less heat loss: Split air conditioner systems are preferable to window and wall air conditioning unit as well. although the latter are small and easy to install, they do not provide reliable cooling to a large space or to multiple rooms. Even with thoroughly sealed windows

and walls, these air conditioner units allow for heat to enter the space partially negotiating the effects of the system. Targeted heating and cooling: Additionally, its possible to have more than one indoor evaporator and fan. You could have one in each room or area of your home and run them each independently with only one outdoor compressor. This combines the efficiency and customization of a space heater or fan with the convenience of central air.

4.1.3 CENTRAL AIR CONDITIONER SYSTEM: The best air conditioner is the one you don’t have a think about. It comes on the moment the indoor temperature set on the thermostat requires cooling performance and then runs quietly and efficiently when needed. But when its to perform routine maintenance, make repairs or replace your system it helpful to understand how an air conditioning system works.

PARTS OF A CENTRAL AC SYSTEM: To get better sense of how your air is cooled, it helps to know a little bit about the parts that make up the air conditioning system. A typical central air conditioning systems is a two-part or split systems that includes: The outdoor unit contains the condenser coil, compressor, electrical components and a fan. The evaporator coil, which usually installed on top of the gas furnace inside the home. A series of pipes, or refrigeration lines, connecting the inside and outside equipment. Refrigerant, the substance in the refrigeration lines that circulates through the indoor and outdoor unit. Ducts that serve as air tunnels to the various spaces inside your home. A Thermostat or control system to set your desired temperature.

Fig: 4.3 Central Air Conditioner System

The Refrigerant cycle: Using electricity as its power source, the refrigerant flows through a closed system of refrigeration lines between the indoor unit and the outdoor unit. Warm air from the inside of your house is pulled into ductwork by a motorized fan. The refrigerant is pumped from the exterior compressor coil to the interior evaporator coil, where it absorbs the heat from the air. This cooled air is then pushed through connecting ducts to vents throughout the home, lowering the interior temperature. The refrigeration cycle continues again, providing a consistent method to keep cool. Benefits: Indoor comfort during warm weather – Central air conditioning helps keep your home cool and reduces humidity levels. Cleaner air – As your central air conditioning systems draws air out of various rooms in the house through return air ducts, the air is pulled through an air filter, which removes airborne particles such as dust and lint. Sophisticated filters may remove microscopic pollutants, as well. The filtered air is then routed to air supply duct – work that carries it back to rooms. Quieter operations – Because the compressor-bearing unit is located outside the home, the indoor noise level from its operations is much lower than that of a free – standing air conditioning.

4.1.4 PACAKAGED AIR CONDITIONER SYSTEM: Package air conditioner is a bigger version of the window air conditioner. However unlike window air conditioner or PTAC units, it has a higher cooling or heating capacity and is usually able to cool an entire house or a commercial building. The nominal capacities ranges from 3 ton to 15 ton. The conditioned air are transferred to the space to be conditioned through ducting which is usually hidden in the ceiling and wall of the building. The unit is placed outside the house, a special room in a building or even on top of a roof. This unit is factory assembled and skilled techniques are needed to uninstall this type of unit. Protection devices such as high/low pressure switch, overload relays for all motors, water flow and air flow switches are included in the units. The compressor have winding protection thermostat built into the winding to disconnect the circuit in the event of overheating. There is an interlocking circuit with the evaporator fan motor starter to ensure that the compressor can only start if the fan motor is running.

COMPONENTS: This self contained unit is assembled in a casing where all the air conditioning components are housed. They include:  Compressor usually hermetic or semi – hermetic type for operation on 380/400 Volts 3phase is used.  water – cooled or air – cooled condenser  . Electric panel  Thermostatic Expansion valve  Air filter.  Front Panel & Return Air Grill.  Evaporator coil.  Evaporator Fan and Housing  Heating and humidifying components may be included in the unit. Dehumidification is needed for cooling mode during summer and Humidification for heating mode during winter.

Fig : 4.4 Packaged Air Conditioner System

CHAPTER 5 COMPONENTS OF AIR CONDITIONER

5.1 MAIN COMPONENTS OF AC:  COMPRESSOR

 CONDESER  EXPAMSION VALVE  EVAPORATOR 5.1.1COMPRESSOR:

Fig: 5.1 Compressor Air conditioner compressor is used to remove the heat laden vapour refrigerant from the evaporator of air conditioning system .the compressor compresses or squeezes the vapour into smaller volume at higher temperature. An electric motor is also be used to drive it directly. In the study and analysis of performance of major components of refrigeration equipment the compressor is first component is the dealt with. Compressor is the heart of the compression system. It is drive by an electric motor and is located between the evaporator and condenser. it basic function is to create motive force in the refrigerant vapour so that the refrigerant sustains motion in the system. Compressor draws refrigerant vapour leaving the evaporator during suction. The suction line falls on low pressure side of the system. The vapour is compressor to high pressure and discharged out of compressor to condenser that line on high pressure side of the system.

TYPE OF COMPRESSORS:     

Reciprocating Air Conditioner Compressor. Scroll AC Compressor Screw AC Compressor Rotary Air Conditioning Compressor Centrifugal Air Conditioning Compressor

Reciprocating compressor: The reciprocating compressor is the most popular type of AC compressor. A piston compresses the air by moving up and down inside of a cylinder. As the piston moves down, it creates a vacuum effect that sucks in the refrigerant. As it moves up, the gas compresses and moves into the condenser. A reciprocating air conditioning compressor is very efficient, as AC units can have up to eight cylinders within the compressor.

Scroll compressor: Scroll air conditioning compressors contain one fixed coil—called the scroll—in the center of the unit, and then there is another coil that rotates around it. During this process, the second scroll pushes the refrigerant towards the center and compresses it. Scroll compressors are quickly becoming as popular as reciprocating compressors because they do not have as many moving parts and are therefore more reliable. Screw type compressor: The screw compressor is extremely reliable and efficient, but it is mainly used in large buildings where there is a vast amount of air that requires continuous cooling. A screw air conditioning compressor contains two large helical rotors that move the air from one end to the other. As the refrigerant moves through the compressor, the space gets smaller, and it gets compressed. Rotary conditioning compressor : Rotary compressors are small and quiet, so they are popular in locations where noise is a concern. The inside of this type of AC compressor contains a shaft with several blades attached to it. The bladed shaft rotates inside the graduated cylinder, consequently pushing the refrigerant through the cylinder and compressing it simultaneously

Centrifugal conditioning compressor : The final type of AC compressor is the centrifugal compressor. As the name implies, it uses centrifugal force to pull in the refrigerant gas and then spins it rapidly with an impeller to compress it. Centrifugal air conditioning compressors are usually reserved for extra large HVAC systems. 5.1.2 CONDENSER:

Fig: 5.2 Condenser

Condenser is that component which is placed next to compressor in a vapour compressor refrigeration system. It is heat exchanger that effect transfer between refrigerant gas, vapour or super saturated vapour coming from compressor and cooling medium such as air or water.

CLASSIFICATION OF CONDENSER: Condensers are broadly divided into three types. They are 1. Air Cooled Condenser 2. Water Cooled Condenser 3. Evaporative Condenser All of these serve the industrial refrigeration field as well. In comparison to the airconditioning industry, however, a lower percentage of air-cooled condensers and a higher percentage of evaporative condensers are operating in industrial refrigeration plants. In industrial refrigeration practice, it is common to connect the evaporative condensers in parallel a concept not normally used in air conditioning. Air cooled condenser:The building blocks of an air cooled condenser. An air cooled condenser is made up of modules that are arranged in parallel rows. Each module contains a number of fin tube bundles. An axial flow forces the cooling air across the heat exchange area of the fin tubes.

Fig: 5.2.1 Air Cooled Condenser Water cooled condenser:The function is to reject the heat that was absorbed by the refrigerant in the evaporator. Water is used to cool the hot air refrigerant (180°F or 82°C) from the compressor by pumping counter-flow water in the condenser.

Fig: 5.2.2 Water Cooled Condenser Evaporative Condenser:An evaporative cooler works by cooling the supply air stream through evaporation of water, which generally results in increased relative humidity inside the home. Evaporative

condensers use the same principle but to cool the refrigerant at the outdoor condensing unit by cooling entering condenser air.

Fig:5.2.3 Evaporative Condenser 5.1.3 EXPANSION DEVICES:

Fig: 5.3 Expansion device An expansion device is needed in every compression refrigeration system to control the flow of liquid refrigerant into evaporator high pressure liquid refrigerant from compressor flows to an expansion device which expands it down to evaporator pressure. An expansion device thus compress the dividing point between the high pressure and low pressure side of the system. Expansion device also meters the quantity of flow of refrigerant through it into the evaporator . the purpose of the an expansion device is therefore , two fold : i. ii.

A thermodynamic function i.e., it has to reduce the pressure the pressure of liquid refrigerant ,and Control function i.e., it has to regulate the flow of refrigerant to the evaporator . an expansion device is essentially a restriction on offering resistance to flow so that the pressure drops as in throttling process.

Classification of expansion devices: Basically they are two types of expansion devices namely  Variable - restriction type  Constant - restriction type

In the variable restriction type the extent of opening or flow keeps on changing depending on the type of control. There are two common types of such devices, name i)automatic expansion valve and ii) thermostatic expansion valves In addition to the above there are float valve type devices high side float and low side float valves. The high side float maintains the liquid at a constant level in the condenser and low side float valve maintains the liquid at constant level in the evaporator . hand operator needle valves are also of variable type expansion device A secondary i.e., constant restriction type expansion devices have fixed narrow area of flow. Capillary tube or choke is the best example of this type of expansion device .

5.1.4 EVAPORATOR:

Fig:5.4 Evaporator Evaporator is that component which absorbs heat from its surrounding or space to be cooled or products to be cooled. It employs, for this purpose , a volatile liquid called a refrigerant .quick evaporating refrigerant flows through the coils of evaporator and absorbs the heat of products placed In it . evaporator is installed in a low pressure side of the refrigerant system. Evaporator is known by many names “cooling coil:”, blower coil “ ,chilling unit , unit cooler etc depending on its application . it is in evaporator where the liquid refrigerant after absorbing heat from the products , evaporates and changes into vapour state. The heat picked up by the refrigerant is carried to the compressor and then to the condenser. Pressure in the evaporator should be low in order to evaporate the refrigerant at lower temperature than the required to be maintained in the refrigerated space. CLASSIFICATION OF EVAPORATORS:: Bare Tube Evaporators  Plate Type of Evaporators  Finned Evaporators  Shell and Tube types of Evaporators

Bare tube evaporator :The bare tube evaporators are made up of copper tubing or steel pipes. The copper tubing is used for small evaporators where the refrigerant other than ammonia is used, while the steel pipes are used with the large evaporators where ammonia is used as the refrigerant. The bare tube evaporator comprises of several turns of the tubing, though most commonly flat zigzag and oval trombone are the most common shapes. The bare tube evaporators are usually used for liquid chilling.

FIG: 5.4.1 Bare type Evaporator Plate type of evaporator:In the plate type of evaporators the coil usually made up of copper or aluminum is embedded in the plate so as so to form a flat looking surface. Externally the plate type of evaporator looks like a single plate, but inside it there are several turns of the metal tubing through which the refrigerant flows. Plate Type of Evaporators

FIG: 5.4.2 Plate type Evaporator Finned evaporator:The finned evaporators are the bare tube type of evaporators covered with the fins. When the fluid (air or water) to be chilled flows over the bare tube evaporator lots of cooling effect from the refrigerant goes wasted since there is less surface for the transfer of heat from the fluid to the refrigerant. The fluid tends to move between the open spaces of the tubing and does not come in contact with the surface of the coil, thus the bare tube evaporators are less effective. Shell and tube type evaporator:The shell and tube types of evaporators are used in the large refrigeration and central air conditioning systems. The evaporators in these systems are commonly known as the chillers. The chillers comprise of large number of the tubes that are inserted inside the drum or the shell. Depending on the direction of the flow of the refrigerant in the shell and tube type of chillers, they are classified into two types: dry expansion type and flooded type of chillers.

5.5 BLOWER:

Fig:5.5 BLOWER Air conditioner blower or a fan is one of the key components that is needed as part of the air conditioning systems. The function of the blower is to produce air movement to the space that is being conditioned. There are basically four types of fan that arecommonly used in the HVAC equipment. They are propeller fan, centrifugal fan, vane-axial fan and tube-axial fan. In our project we are using propeller fan as exhaust blower which transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped bade, and a fluid(such as air or water) is accelerated behind the blade. Blower fan motor is a part of HVAC system that is located within the condensing unit. This unit also consists of the compressor and condenser coil. The outdoor unit works to keep the air conditioning unit cool when it is running.

FIG: 5.6 BLOWER MOTOR

5.2 EXPERIMENTAL ACCESSORIES

5.2.1PRESSURE GAUGE:

Fig: 5.7 PRESSURE GAUGE Pressure measurement is the analysis of an applied force by a fluid (liquid or gas) on a surface. Pressure is typically measured in units of force per unit of surface area. Many techniques have been developed for the measurement of pressure and vacuum. Instruments used to measure and display pressure in an integral unit are called present gauges or vacuum gauges. It uses a column of liquid to both measure and indicate pressure. Likewise the widely used for the gas is mechanical device which both measures and indicates and is probably the best-known type of gauges. A vacuum gauge is a pressure gauge used to measure pressure lower than the ambient atmospheric pressure which is set as the zero point in negative values. Most gauges measure pressure relative to the atmospheric pressure as the zero, So this form of reading is simply referred to as “gauge pressure”. However anything greater than total vaccum is technically a form pressure. For very accurate readings, especially at very low pressures, a gauge that uses total vaccum as the zero point maybe used, giving pressure readings in an absolute scale. 5.2.2 Energy meter:

Fig: 5.8 ENERGY METER Energy meter or watt-hour meter is an electrical instrument that measures the amount of electrical energy used by the consumers. Utilities are one of the electric departments, which install these instruments at every place like homes, industries, organizations, commercial buildings to charge for the electricity consumption by load such as by fans, refrigerators, and other home appliances. The basic unit of power is watt and it is

measured by using wattmeter one thousand watt make one kilo-watt. Energy meters measures the rapid voltage and currents, calculate their product and give instantaneous power this Tower is integrated a time interval which gives the energy utilized over that time period. The electricity supply connection may be either single phase or three phase depending on the supply utilized by the domestic or commercial installations. 5.2.3 ROTAMETER

Fig:5.9 ROTAMETER Rotameter is device that measures the volumetric flow rate of fluid in a closed tube. It belongs to a class of meters called variable area meters, which measures flow rates by allowing the cross-sectional area the fluid Travels through to vary causing a measurable effect. A Rotameter consists of tapered tube typically made of glass with a float (shaped weight made either of anodized aluminium or a ceramic), Inside that is pushing up by the drag force of the flow and pulled down by the gravity. A Higher volumetric flow rate through a given are increases flow speed and drag force, so the float will be pushed upwards.  A Rotameter requires no external power or fuel.  A Rotameter is also a relatively simple device that can be mass manufactured out of cheap material.  Since the area of the flow passage increases as the float moves up th tube, the scale is approximately linear.

5.2.4 THERMOCOUPLE:

Fig:5.10:THERMOCOUPLE AThermocouple is an electric device consists of two dissimialar electrical conductors forming n be interpreted to measure temperature. Thermocouples are a widely used type of temperature sensor. The wires that make up the thermocouple must be insulated from each other everywhere, except at the sensing junction. Any additional electrical contact between the wires, or contact of wires to other conductive object modify the voltage and a give a false reading of temperature. Plastics are suitable insulators for flow temperature parts of a thermocouple, whereas ceramic insulation can be used up to around 1000°c. Thermocouples are suitable for measuring over a large temperature range from -270 to3000°c for short , in inert atmosphere.

CHAPTER 6

REFRIGERANTS

6.1 REFRIGERANTS: A refrigerant is any substance which acts as a cooling agent by absorbing heat from another substance. It is a working agent or medium employed in a refrigeration system. It is defined as follows. Refrigerant is the fluid used for heat transfer in a refrigeration system which absorbs heat at a low temperature and low pressure and rejects heat at higher pressure. Either is the first refrigerant known to mankind. In the early days, Ethylchloride (C2H5Cl) was used as a refrigerant which soon gave way to ammonia (NH3) and sulpher dioxide SO2 as early as in 1875. Later with the development of small, automatic domestic and commercial units, refrigerants such as methyl chloride and carbondioxide came into use. During 1910-30 many new refrigerants, such as N2O3, CH4, C2H6, C2H4 and other hydrocarbons were employed for low-temperature refrigeration. A major breakthrough occurred in the field of refrigeration with the development of freons. Freons are a group of fluorinated hydro-carbons, generally known as fluorocarbons derived from methane, ethane etc., 6.2 DESIRABLE PROPERTIES OF AN IDEAL REFRIGERANT:          

Low boiling point and low freezing point Stable over a wide range of pressure and temperatures High critical temperature and low critical pressure Non poisonous, non explosive and non corrosive High enthalpy of vaporization High thermal conductivity Low specific heat in liquid state Low viscosity Easily available, storable and cheap Should not be electrically conductive and hydroscopic.

6.3 A FEW COMMON REFRIGERANTS AND THEIR APPLICATIONS: Primary refrigerants: Primary refrigerant is that which cools the substances by absorbing heat equal to its latent heat them. A few of them are discussed below.

(A) Inorganic Compounds:

(i) R 717 Ammonia (NH3): BP=-33°c; FP=-78°c Toxic, slightly explosive and inflammable Low specific volume in vapour state High refrigerant effect Ammonia should be used with steel pipes and never with copper, brass or their alloys, Extensively used in cold storages, ice plants, food refrigeration plants etc., (ii) R 744 Carbon Dioxide (CO2): BP=-78°c ; FP=-57°c  Odourless, non-toxic, non-flammable  Non-explosive and non-corrosive  Low refrigerating effect Solid carbon dioxide is called Dry Ice. Chiefly used in air-conditioning of theatres, hospitals, hotels etc., where safety is prime consideration. Used on board ships transporting cartons containing perishables. (iii) R 764 Sulphur Dioxide (SO2): BP=-10°c ; FP=-75.5°c  Non-flammable, non-explosive  Works at low pressures

(B) Halocarbons : These are the compounds which contains one or more of the halogens i.e chlorine ,bromine and fluorine . they are obtained after replacing one or more hydrogen atoms in either of the hydrocarbons i.e methane or ethane . mostly flouorinated halocarbon are used as refrigerants of high quality . these are available in the market under trade names , Freon ‘s genetrons , arctons ,isotrons etc..

R11 Trichloro fluoro methane (C CL3 F): BP =-24°c: FP =-111°c  Non toxic , non flammable and non corrosive  Low operating pressure

 Mixes well with mineral lubricating coils  It is used with centrifugal compressor  It is used in 50 tons capacity air conditioning plant R12 Dichloro Diflouro Methane(C CL2F2) BP=-30°c; f=-158°c  Non toxic ,non flammable, non explosive  Highly stable  Condenses at odarate pressures Used in domestic applications and water coolers under the trade name Freon – 12. Freon group is corrsive to magnesium or aluminium.

R-22 Chlorodifluoro Methane(CHCL F2): BP= -40.76°c ; FP= -160°c Trade name : Freon-22 Used with reciprocating copressors in large units such as package units and cental air conditioning plants . it is used for low temperature refrigeration appliacations such as cold storage , food freezing and storage ectc it has refrigerating capacity than of R-12. It needs relatively smaller compressor.

Secondary refrigerants : Secondary refrigerant is that which cools the substances by absorbing theat eual to its sensible heat from them. R729 AIR Bp =-194°c; critical temp = -140°c  Harmless  Freely available  Equipment becomes bulky  High operating cost  Low heating carrying capacity  Low cop

R718 WATER Bp=100°c ; FP=0°c ; critical temp= 374°c  Freely available  Used in system ejector system only for air conditioning

APPLICATIONS OF SPLIT A/C Applications of air conditioner:

1. comfort of conditioning      

Summer air conditioner Winter air conditioner Year round air conditioner Remote unit air conditioner Window air conditioner Desert coolers

2. Industrial air conditioning      

Tool room air conditioning Military applications such as tracking of missiles Atomic sub-marines Modern medicines – manufacture and storage Commercial air conditioning(hotels, cinema halls) Textile ,Printing, Chemical, Biological process industries

P-H DIAGRAM

6.4 P-H DIAGRAM

Fig: 6.1 P-H Diagram

It is pressure – enthalpy diagram and a graphic means of representing the properties of refrigerants. With saturated – liquid and saturated – vapour lines as the references, lines of constant temperature, entropy, and specific volume are found in the diagram, The sub – cooled liquid region falls to the left of the saturated – liquid line. In the region the constant – temperature line is almost vertical. This line is horizontal in the mixture region because here the temperature must correspond with the saturation pressure. Space between the two reference lines is liquid – vapour mixture region, The saturated region lies to the right of saturated – vapour line. The line of constant temperature here drops first slightly to the right and them vertically. The line of constant volume slopes upward to the right. The line of constant entropy runs upward to the right. Hence a reversible adiabatic compression, which is isentropic, shows the increase in enthalpy as the pressure increases during compression.

CHAPTER 7 TEST RIG OF Split A/C

WHAT IS TEST RIG OF A/C:

Fig:7.1TEST RIG OF SPLIT A/C The Air Conditioning test rig works on simple vapour compression refrigeration cycle using R22 as a refrigerant. The system is fabricated such that student can study all the air conditioning processes. It is also useful to understand working of all the components of system, their performance and control etc.. The experimental refrigeration cycle test rig consist of a compressor unit, condenser, evaporator, cooling chamber, controlling devices and measuring instruments those are fitted on a stand and a control panel. The apparatus is fabricated in such a way; to refrigeration system hermetically sealed compressor is fitted on stand with the help of flexible foundation bolts to minimize vibrations. Electric power input to the compressor is given through thermostatic switch. 7.1 SPECIFICATIONS:     

Compressor : Scroll type : 50HZ : 240V Condenser: Axial fan Expansion device: capillary tubes : 3rows : 60dia : 22inc Evaporator Blower unit: Centrifugal forward curved fanPressure gauges for measurement of pressures

7.2 EXPERIMENTAL SET–UP: 1. Systems assembly includes compressor, condenser, evaporator or expansion device, and filter. 2. Motor with blower & fan assembly includes, a double ended shaft motor, a fan and motor and suitable bracket for it. 3. Cabinet and air distributing assembly – it includes a cabinet as enclosure for whole systems, an air distributing systems 4. Control panel assembly – it includes the switched those required to control the entire AC system as per the requirement, IC temperature, humidity etc The AC Test Rig is designed and fabricated, to determine the performance and to study its working principle. The AC test rig consist a 1.5 T sealed compressor unit, a finned condenser (heating coil) and evaporator (cooling coil), a double ended (shaft) motor to run fan and blower simultaneously and fitted on wooden stand and properly covered by grill. A duct is assembled along with blower unit as a carrier of comfort air, the velocity of the air passing through the coil is measured by using a pilot tube fitted in duct itself and connected to V- tube manometer which is fitted on control panel. The control panel is fitted over compressor and fan0blower assembly. Control panel consists of 1 phase energy meter to measure power consumed by compressor, a Rotameter to measure flow rate of refrigerant pressure gauge to measure pressure of discharge side compound vaccum gauge to measure suction side pressure, a digital temperature indicator to measure temperature at various places. The desired temperature find out by changing position of selector switch with it. 7.3 PROCEDURE: Switch on the compressor and let it run for considerable time. Say for automatic cut off by thermostatic switch at normal position. Fill a measured quantity of water in ice cane (100 gm) and put it into cooling chamber. Measure initial temperature of water before putting into cooling chamber by noting the value of T4 as T4i note down the energy meter reading. Wait till compressor starts. Compressor shall be started automatically as and when temperature of cooling chamber falls up to adjusted temperature. After starting the compressor note down the temperature T4 at the interval of every 15 minutes and note it down as T4C. Note down the power consumed by compressor till ice forms i.e. temperature T4 should reach O°C. At 0°C of ice cane note down all the temperature i.e. T1, T2, T3, T4 and T5. Also note down the suction and discharge pressure by the respective gauges. Note down the flow rate of refrigerant by rotometer.

DETERMINATION OF C.O.P DETERMINATION OF COP: Using p-H chart for Make state points, 1.(P1,T1) ; 2.(P2,T2) 3.(T3) ; 4.(T4) And read out enthalpies H1,H2,H3 and H4

C.O.P = (H1-H4) / (H2-H1)

T1 =

P1 =

T2 =

P2 =

T3 =

P3 =

T4 =

P4 =

NOTE: Psi = Pounds Per Sq. inch (1b/in2) Kpa = KN/m3 ;1 Psi = 6.9 kpa

Form P-H charts H1=

H2=

H3=

H4=

Net refrigeration effect, N = H1 – H4 Work supplied = Compressor power input = W W =H2 – H1

C.O.P = N \ W Net refregitoration effect

Actual COP = compressor power consumption +fan power consumption 𝑁

= 𝑊𝑐+𝑊𝑓 If flow rate of refrigerant (measured at the exist of condenser) is 1 lit/min i.e., 10 -3/min, and density ρ of refrigerant as read from tables or chart is 1200kg/m3, then M, mass flow rate = V. ρ i.e., m = let energy meter constant be let time taken for 5 revolutions total revolution/sec energy consumed by fan = thus, wf = COP =

CHAPTER 8 CONCLUSION

CONCLUSION: In this project we studied about the details about split air conditioner. Its basic construction with all the related diagrams, we determine the coefficient of performance of split air conditioner by installing the various accessories like gauges, flow meter and thermocouples.

PHOTO GALLERY

REFRENCES REFERENCES:    

A Text Book of Refrigeration And Air Conditioning by RS Kurmi and JK Gupta A Text Book of Refrigeration And Air Conditioning by Arora A Thermak text Book of Thermal Engineering by Rudramurthy Ramesh Chandra. “Mechanical Vapour Compression refrigeration”. Refrigeration and Air Conditioning New Delhi Indian PHI Learning. P.3ISBN81-203-3915-0 .  Refrigerator – adjusting Temperature Controls. Geappliances.com Brustall, Aubery F. (1965). A history of mechanical engineering . the MIT press. ISBN 0262-52001-X. “improved process for the artificical production of ice” , U.S patent office, patent 8080, 1851 Dennis R. Heldman (29 august 2013), encyclopedia of agricultural, food, and biological engineering (print). CRC PRESS.P.350. ISBN 978-0-8247-0938-9 “freezing and food safety” USDA. Retrieved 6 august 2013 Production-household refrigerators – country any region comparisons. Statinofo.biz. retrieved on 26 august 2013 Refrigerator -adusting

ANNEXURE ANNEXURE Fig: 3.1 Air Conditioner-schematic of systems Fig: 4.1 window Air Conditioning system Fig: 4.2 Split Air Conditioning system Fig: 4.3 Central Air Conditioning system Fig: 4.4 Packaged Air Conditioning system Fig: 5.1 Compressor Fig: 5.2 Condenser Fig: 5.2.1 Air cooled Condenser Fig: 5.2.2 Water cooled Condenser Fig: 5.2.3 Evaporative Condenser Fig: 5.3 Expansion Valve Fig: 5.4 Evaporator Fig : 5.4.1 Bare Tube Evaporator Fig : 5.4.2 Plate type Evaporator Fig :5.5 Blower Fig: 5.6 Blower Motor Fig: 5.6 Pressure Gauge Fig: 5.7 Energy Meter Fig: 5.8 Rotameter Fig: 5.9 Thermocouple Fig:6.1 P-H Diagram Fig: 7.1 Test Rig of Split Air Conditioner