Chain Drive

A

Problem Based Learning Report On

Design of Evaporator Cooler For the subject of REFRIGERATION AND AIR CONDITIONING Under the guidance of PROF. N. S. AHER By SR NO. 1 2 3 4

BATCH T-10 T-10 T-10 T-10

PROF. N. S. AHER (Name & Sign of Guide)

CLASS TE-C TE-C TE-C TE-C

ROLL NO 212 214 215 216

NAME Jathar Kunal Kamlakar Hajare Mayuresh Mehetre Vaibhav Balasaheb More Ajay Nimba

SIGN

Dr. A.G. THAKUR Vice Principal & Head Mechanical Engineering Department

A) :-PEOs:1.To prepare students for successful and efficient careers in industry that meet the needs of Indian and Multinational companies. 2.To develop the ability among students to synthesize and analyse the data and technical Concept for application to product design and development. 3.To provide opportunity for students to work as part of teams on multi-disciplinary Projects. 4.To provide students with a sound foundation in the mathematical, scientific and engineering fundamentals. 5.To promote awareness among students about life-long learning and to introduce them to professional ethic and code of professional practice. 6.To inculcate in student’s ethical values and belongingness towards society. 7.To provide opportunity to undertake innovative projects and research. 8.To make students aware of the latest developments in engineering and technology.

POs : 1.Demonstrate ability to apply basic knowledge in mathematics, science and engineering. 2.Demonstrate the ability to conduct experiments, interpret and analyse data, and report results. 3.Demonstrate the ability to design mechanical systems, in general and a thermal system or a process that meets desired Specifications and requirements. 4.Demonstrate the ability to function in a team as a member or a leader. 5.Demonstrate the ability to identify, formulate and solve Mechanical Engineering problems. 6.Demonstrate and understanding of their professional and ethical responsibilities. 7.Communicate effectively in both verbal and written forms. 8.Have the confidence to apply engineering solutions in global and societal contexts. 9.Capable of self-learning. 10.Familiar with modern engineering software tools and equipment to analyse mechanical engineering problems. 11.Capable to demonstrate creativity. 12.An ability to prepare design documentations and to make effective presentations.

Introduction

The global population in the year 2008 has hit an unprecedented level of 6.5 billion. It continues to rise drastically, and is predicted to hit 8 billion by the year 2025 (United Nations, 2008). In addition, with the economic rise of highly populous countries such as China and India, there is also an unprecedented rise in the overall global standard of living. From an agriculture perspective, these facts translate into an immense increase in the demand for food. Naturally, this entails a subsequent increase in the price of food and agricultural products worldwide. It should also be noted that industries such as the biofuel industry constitute market forces that contribute to the rise in the demand and price of agricultural products. Agricultural engineers are faced with the task of not only meeting the food requirements of the ever increasing global population, but to also maintain relatively low costs for food products. From basic economics principles, stabilizing the cost of a product undergoing an increase in its demand requires either an increase in its supply or a decrease in its cost of production. However, with agricultural products, such a task is not so simple: the amount of land that can be cultivated has reached its practical limit. Furthermore, soaring energy prices continue to push the costs of production from the growing stage to the transportation stage of production higher and higher. The only possible way left to stabilize the cost of food is to establish and implement new and efficient methods for crop production, post-harvest drying and storage, as well as distribution and transportation. It should be noted, that such Although all of these aspects are important when trying to tackle the challenge of meeting stabilizing the cost of food, this design project only explores the post harvest storage aspect of food production. In southeast Asia, postharvest losses range from 10%37% for rice (International Rice Commission, 2002). Furthermore, in India, post harvest losses are in the range of 25-50%. These losses translate into a significant loss in the overall supply of agricultural products.

(Fig No 1.1)

EVAPORATIVE COOLING SYSTEM DESIGN The evaporative cooling system was designed to deliver a quasiuniform mass of air in terms of temperature and relative humidity. The theoretical expectation for the design was that a control volume (in the present case, a cold storage room) would eventually be in equilibrium with the incoming air. Once the point of equilibrium was reached, it was postulated that the humidifying system would maintain the temperature and relative humidity at a relatively constant level. Simply providing moisture to a control volume will provide a certain amount of cooling but only in a batch process: after saturation conditions are reached, no further cooling can be provided and the temperature will increase due to heat influx from the higher temperature ambient surroundings. For this reason, it was decided to provide an air flow Evaporative Cooling Design Set-Up: The set-up consisted of the following components: - Humidifying unit (MDFD-1) - Mixing chamber - Blower - Delivery pipe - Insulating foam to insulate door opening - Cold storage room at Bioresource Engineering Machine Shop

(fig 1.2)

MATERIALS AND METHOD Design Criteria of the Cooling System The storage system is rectangular in shape, and the design specifications for the system as well as the reservoir seat were done. Design of Front and Rear Sides of the Storage System The design of the rear side of the system was achieved using Equation (1) Ar=Hr*Lr……………(1) (1) Ar = 0.8 × 0.4=0.32m2 Where; Ar = Area of rear side, Lr = Length of rear side, Hr = Height of rear side Design of Left and Right Hand Sides of the Storage System (Pad Area) The design for the left side of the storage system was done using Equation (2); AL= HL*BL…………(2) Al = 0.8 × 0.5= 0.4m2 Where; A l = Area of left side of the storage system, H l = Length of left side of the storage system, B l= Breadth of left side of the storage system. A = pi*r2 …………….(3) A= 3.14*0.122= 0.045m2 Where; A = Area, r = Radius Design of Top of the Storage System The design for the top of the storage system was done using Equation (4); At=Lt*Bt ………………….(4) At = 0.5× 0.4= 0.2m2 Where; At = Area of top of the storage system,

Lt = Length of top of the storage system Bt = Breadth of top of the storage system,

Design of Reservoir Seat: The design for the reservoir seat was also done using Equation (5); As=LS*BS………………. (5) As = 0.5× 0.3= 0.15m2 Where; As = Area of reservoir seat, Ls = Length of reservoir seat, Bs = Breadth of reservoir seat Volume of the Storage System: The capacity of the storage system was determined using Equation (6); Vc = Lc×Bc×Hc…….. (6) Vc = 0.4 × 0.5 ×0.8= 0.16m3 Where; Vc = Volume of the storage system, Lc = Length of the storage system, Bc = Breadth of the storage system, Hc = Height of the storage system Volume of Reservoir: The volume of the reservoir was determined using Equation (7); Vr =pi*r*2h………………. (7) Vr = 3.14 × 0.162 × 0.3= 0.024m3=24litres Where; Vr = volume of reservoir, pi =3.14, r= radius of reservoir, Hr = height of reservoir Design of Battery Charger The battery charger was designed so that it can step down the voltage rating from the solar panel from 18V to 15V in order to charge the battery adequately. The battery charger was designed in accordance with Tharaja, (1995) as shown in Equation (10). RT= R1+R2+R3+R4= 0………… (10)

RT= 120+2+2+1= 125 I= V/R = 18/125 = 0.12A V= IR =0.12*125= 15V

CONCLUSIONS An evaporative cooling system was designed and constructed for preservation of fresh vegetables, The evaporative cooling system works on the principle such that warm dry air is cooled and humidified by passing through a jute bag. We Have concluded this PBL by understanding the Design Procedure of the Evaporator cooler.The parameters that we have to considered for designing the suitable cooling unit understand by this Problem Based Learning Activity.

REFERANCE -ASHRAE. Handbook of Standards. American Society of Heating and Refrigeration and Air Conditioning. -Thakur, BC, Dhingra DP Parameters Influencing the Saturation Efficiency of an evaporative -www.arpnjournals.com