Tandem Cooler Research Paper

Tandem Cooler maximizing effectiveness, mimimizing energy consumption

Mohnish Paranjape, Himalay Dunakhe, Pavan Paradkar and Mahesh Nimbalkar
Department of Mechanical Engineering, DON BOSCO INSTITUTE OF TECHNOLOGY MUMBAI-400070, INDIA

This paper presents a design of Tandem Cooler (tandem: work in series) intended to overcome disadvantages in a Desert cooler and increase the effectiveness and lowering energy consumption by incorporating following changes: 100 watts motor propelling the centrifugal pump and fan; a new design layout and use of user controlled sprinklers making the product more energy efficient and affordable to customers. Keywords— tandem; direct evaporative cooling; Moist air load; magnetically coupled;

It converts electrical power in to mechanical power. It gives rotary motion to Centrifugal Pump.
Motor selection depends upon loads which are to be overcome to provide required cooling.
1. DENSE AIR / MOIST AIR LOAD
2. WATER LOAD / PUMP LOAD

3.1.1 PUMP POWER CALCULATION
Consider, Discharge Q = 15 lit/min = 0.9 m³/hr Density of fluid ρ = 1000 Kg/ m³
Gravitational acceleration g = 9.81 m/s²
Differential head h = 12 m

Find: - Hydraulic Power Ph = 29.43 W
Pump Shaft Power (Power required to be transferred from motor to pump shaft) Ps :- …. (Assume Efficiency factor = 60%)

We select Single Phase Induction Motor with Power= 100 W Frequency = 50 Hz, Rpm = 2000

3.2 DESIGN OF SHAFT
The shafts may be designed on the basis of
1. Strength, 2. Rigidity and stiffness.
In designing shafts on the basis of strength, the following cases may be considered:
1. Twisting moment or torque only,
2. Bending moment only,
3. Combined twisting and bending moments

3.2.1 SHAFT SUBJECTED TO TWISTING MOMENT OR TORQUE ONLY
For Motor Power = 100 W RPM =

3.3 BODY FRAME DESIGN
Frame is required for mounting different parts of project. It is used to sustain vibration due motor and centrifugal pump and motor.
It provides the necessary rigidity to the set up.

Figure (3) (All dimensions in cm)
Material used for frame is cast iron
For the water tank, same iron angle bars can be used on its edges, to give required support. And for the surface and enclosure, sheet metal can be used which is processed. As it will be in continuous contact with the water, hence the chances of attacked by rust are greater, hence properly galvanized and anti-rust coated metal sheets are used.
Iron strips can be attached wherever support is required for the tank.
The density of cast iron is 7.8×10-3 kg/cm3.
Selection of cross section: L shaped angle iron bar:

Figure (4) (All dimensions in cm)

Total length of angle iron bar required 10m.
Calculation of weight of frame: ρ =7.810-3 kg/cm3.
C/s area = 3 x 0.15 + 2.85 x 0.15 = 0.8775 cm2
Volume = 1000 x