How to build your own small Air Conditioner

How to build your own small Air Conditioner

Now a day in summer season everyone is affected by sun, heat and need some relief to survive this season without having any heat strokes. One way is to pass time under some shady trees. But what if you don’t have one near you, or you don’t want to do that. Then you have to buy an A.C (air conditioner) which is very costly. To avoid heat and expenses as well, I’m going to tell you about some easy way to get your own Air Conditioner in a very low cost. Another advantage is that it is very small as compared full size A.C of companies. You can also use it in your car as it is small and need electricity almost equal to the battery of a car. Now without wasting your time, I tell you how to build one of your own A.C.

Ø  First of all take water bucket or an ice cooler.

Ø  Make sure it does not leak.

Ø  Now put some packing foam blocks inside of the bucket. If you are using an ice cooler then you don’t have to put anything in it as it already has mechanism.

Ø  Now make two or three holes in the bucket that also pass through foam blocks.

Ø  Make one or two holes in the lid of bucket by keeping in mind that how many small fans can be fitted in the lid. These holes should be about the size of the small fans you bought.

Ø  Now fit the fans/fans on the lid in such a way that it should through the air inside the bucket.

Ø  Fill the bucket with cold water below the holes you made or put some ice blocks in it.

Ø  Now fix the lid on the bucket.

Ø  Connect the wires of fans with your car battery and run the fans.

Ø  You will feel cool air coming out of the holes you made inside the bucket.

This your own Air Conditioner which you can use at small scale, e.g. for only one person in small areas or in your cars. This idea is very low cost and almost everyone can afford it.

Now you can spend your summers in ease and can have a pleasure weather in your small world of cars. Driving also becomes safe if you don’t have to worry about clearing your forehead full of sweat.

Hope you liked it give me your feedbacks via comments.

Thank you J

Brinell Hardness Testing Machine:

The Brinell scale characterizes the indentation hardness of materials through the scale of penetration of an indenter, loaded on a material test-piece. It is one of several definitions of hardness in materials science.

Proposed by Swedish engineer Johan August Brinell in 1900, it was the first widely used and standardised hardness test in engineering and metallurgy. The large size of indentation and possible damage to test-piece limits its usefulness.

The typical test uses a 10 millimetres (0.39 in) diameter steel ball as an indenter with a 3,000 kgf (29 kN; 6,600 lbf) force. For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball. The indentation is measured and hardness calculated as:

where:

P = applied force (kgf)

D = diameter of indenter (mm)

d = diameter of indentation (mm)

The BHN can be converted into the ultimate tensile strength (UTS), although the relationship is dependent on the material, and therefore determined empirically. The relationship is based on Meyer's index (n) from Meyer's law. If Meyer's index is less than 2.2 then the ratio of UTS to BHN is 0.36. If Meyer's index is greater than 2.2, then the ratio increases.

BHN is designated by the most commonly used test standards (ASTM E10-12 and ISO 6506–1:2005 ) as HBW (H from hardness, B from brinell and W from the material of the indenter, tungsten (wolfram) carbide). In former standards HB or HBS were used to refer to measurements made with steel indenters.

HBW is calculated in both standards using the SI units as

where:

F = applied force (N)

D = diameter of indenter (mm)

d = diameter of indentation (mm)

Features:

• Low Load Brinell up to 187.5 kgf
• Full Load Brinell up to 3000 kgf
• Built-in Optical Measurement System
• Automatic Measurement Option
• RS232C Output
• Automatic Test Cycle Option
• X-bar And Range Output

Procedure:

The Brinell test, consists of applying a constant load or force, usually between 500 and 3000 Kgf, for a specified time (from 10 - 30 seconds) using a 5 or 10 mm diameter tungsten carbide ball. The load time period is required to ensure that plastic flow of the metal has ceased. Lower forces and smaller diameter balls are sometimes used in specific applications. Similar to Knoop and Vickers testing, the Brinell test applies only a single test force. After removal of the load, the resultant recovered round impression is measured across diagonals at right angles and is usually recorded millimeters using a low-power microscope or an automatic measuring device.

The actual Brinell hardness (BHN) is calculated by factoring the indent size and the test force however it is not necessary to make the actual calculation for each test. Calculations have already been made and are available in tabular form for various combinations of diameters of impressions and load. In addition various forms of automatic Brinell reading devices are available to perform these tasks.Brinell testing is typically used in testing aluminum and copper alloys (at lower forces) and steels and cast irons at the higher force ranges. Highly hardened steel or other materials are usually not tested by the Brinell method, but the Brinell test is particularly useful in certain material finishes as it is more tolerant of surface conditions due to the indenter size and heavy applied force. Brinell testers are often manufactured to accommodate large parts such as engine castings and large diameter piping.

RLC Circuit:

An RLC circuit (the letters R, L and C can be in other orders) known as  resonant circuit, tuned circuit, or LCR circuit,  is an electrical circuit consisting of a resistor, an inductor, and a capacitor, connected in series or in parallel. The RLC part of the name is due to those letters being the usual electrical symbols for resistance, inductance and capacitance respectively. The RLC circuit exhibits the property of resonance in same way as LC circuit exhibits, but in this circuit the oscillation dies out quickly as compared to LC circuit due to the presence of resistor in the circuit.

 Applications:

Variable tuned circuits

 Filters

 Oscillators

 Voltage multiplier

 Pulse discharge circuit

Single Phase:

In electrical engineering, single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors. A single-phase supply connected to an alternating current electric motor does not produce a revolving magnetic field; single-phase motors need additional circuits for starting, and such motors are uncommon above 10 kW in rating.

Standard frequencies of single-phase power systems are either 50 or 60 Hz. Special single-phase traction power networks may operate at 16.67 Hz or other frequencies to power electric railways.

Poly Phase:

A polyphase system is a means of distributing alternating-current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. Polyphase systems are particularly useful for transmitting power to electric motors. The most common example is the three-phase power system used for industrial applications and for power transmission. A major advantage of three phase power transmission (using three conductors, as opposed to a single phase power transmission, which uses two conductors), is that, since the remaining conductors act as the return path for any single conductor, the power transmitted by a balanced three phase system is three times that of a single phase transmission but only one extra conductor is used. Thus, a 50% / 1.5x increase in the transmission costs achieves a 200% / 3.0x increase in the power transmitted.

How 3-Phase Works

A 3-phase circuit combines three alternating currents of the same frequency, each 120 degrees out of phase with each other. This produces three separate "waves" of power, as represented below. The power in a 3-phase power supply never drops to zero, but in single-phase the power falls to zero 3 times per cycle. Thus, in a 3-phase power supply, the power delivered is constant.

Single vs 3-Phase power diagram

While actual efficiency depends on the load-to-capacity ratio, the nominal ratio between the efficiencies is 1.5 in favor of 3-phase when comparing single- and 3-phase power.

Junker's Gas Calorimeter

1.      History:

The junker’s gas calorimeter was named by Antoine Lavoisier. In 1870, he used guinea pig with this device to measure heat production in his experiments. The heat produced by the pig melted the snow arround the calorimeter. This shows that respiratory is the combustion similar to burning of candle. The junker’s gas calorimeter is almost similar to bomb calorimeter in respect that heat evolved by burning gas is taken away by water. 

2.      Description:

The junker’s gas calorimeter is used to determine the calorific value of the gaseous fuels.

2.1.Construction:

The junker’s gas calorimeter is a device used to measure the calorific value of the gaseous fuels. The device is essentially a Bunsen burner with a cooling jacket. The jacket is cylindrical in shape  with water in it. The burner is inside the cylinder. The calorimeter allows the user to measure the temperature of water flowing in and flowing out. Once steady state is reached, the water flowing through is collected for a specified period of time. Measuring the mass of the water and the temperature rise in the water, the operator can calculate the number of joules which went into the water to heat it. There is a flow meter on the fuel gas, so the operator can also calculate the volume of gas that was burned in the same time period. The amount of energy, in J, available per litre of gas can then be calculated. A Junkers calorimeter is a flow calorimeter, with heat transfer happening continuously, as opposed to a batch calorimeter. 

 The device consist of a cylindrical shell and two paths for water are there which have copper coil arranged in it. One path is the inlet and the other is outlet. Water pass through the copper coils. There is pressure regulator in the path of water flow which is further connected with gas flow meter. Gas flow meter is used to measure the flow rate of gas. Temperature sensors are used in the device to measure the inlet and outlet water temperature and also for the flue gases. 

2.2.Main Parts:

1. SHELL

2. WET TYPE LABORATORY GAS METER

3. PRESSURE REGULATOR

4. AIR HUMIDIFIER

5. FUEL BURNER

6. AIR INLET

7. COOLING WATER

8. COOLING WATER CHAMBER

9. THERMOMETER (INLET WATER TEMPERATURE)

10. THERMOMETER (OUTLET WATER TEMPERATURE)

11. FLUE GAS OUTLET

12. CONDENSATE OUTLET

2.3. Working:

The junker’s gas calorimeter works on the principle of burning of a gas whose volume is known. The temperature of water and gas is measured along with flow rate of gas to measure the calorific value. The formula is:

 Calorific Value of Gas X Volume of Gas = Volume of water X Rise in Temperature, is then used to determine the Calorific Value of the Gas (assuming that heat capacity of water is unity). 

A measured quantity of gas whose calorific value is required supplied to a gas meter which measures the volume of gas and after it the gas pass through the pressure regulator which measures the pressure of gas using the manometer. When the gas inside the chamer is burned, the products produced in the combustion rise into the chamber and then move downward where it is extracted as gas flues. After this gas finally escapse to the atmosphere. There is thermometer at the end of the outlet which measures the temperature of the escaping gas. This temperature should be near room temperature so that whole heat is absorbed by the water. Cold water enters the calorimeter near the bottom of device and leaves from top. Water that was formed by condensation is collected in a pot. The quantity of gas in te process is measured accurately and the temperature of ingoing and outgoing gas is also measured. By using above ccollected data we can measure the calorific value from formula as mentioned earlier. 

3.      Example:

Following results were obtained when a gas was tested in a junker’s gas calorimeter:

Gas burnt in calorimeter = 0.08m3

Pressure of gas supply = 5.2 cm of water

Barometer  = 75.5 cm of Hg

Temperature of gas = 13 degree centigrade

Weight of water heated by gas = 28 kg

Temperature of water at inlet = 10 degree centigrade

Temperature of water at outlet = 23.5 degree centigrade

Steam condensed = 0.06 kg

Determine the higher and lower calorific values per meter cube of gas at temperature of 15 degreecentigrade and barometeric pressure of 76 cm of Hg.

Solution:

The volume of gas is measured at 13 degreecentigrade and pressure of 5.2 cm of water. Let us reduce this volume to S.T.P. by using general gas equation.

P1V1/T1 = P2V2/T2

P1 = 75.5+ (5.2/13.6) = 75.882 cm of Hg

T1 =  273+13 = 286K

V1 = 0.08 m3

P2 = 76 cm of Hg

V2 = ?

T2 =  273+15 = 288K

75.882 x 0.08/286 = 76 x V2/288

V2 = 75.882 x 0.08 x 288/76

V2 = 0.0804 m3

Heat received by water = 28 x 4.18 x (23.5 – 10) = 1580 KJ

Higher calorific value of fuel = 1580/0.08 = 19750 KJ/m3

Amount of water vapours formed(steam condensed) per m3 of gas burnt = 0.06/0.08 = 0.75 Kg

Lower calorific value (L.C.V) = H.C.V -2465 x 0.75

                                                 = 19750 – 1848.7 = 17901.3 KJ/Kg