# I with steam boiler + generator theory

• khometmibro1
In summary, the two groups found different efficiencies for the same potentiometer setting. This may have to do with the fact that the loads used in the experiments were different and the power of the generator.
khometmibro1
Hi. My group and I did a practical the other day and we have to write a lab report on it using our data and the data of another group.

The steam boiler creates steam which is fed through a nozzle to a turbogenerator. The generator creates electricity, and this is fed into a loop with a potentiometer, like this:

http://i.imgur.com/auKVlzP.png

The strange thing is that for our group's data, the highest potentiometer setting gives the lowest efficiency. While for the other group's data, the highest setting gives the highest efficiency. AFAIK a potentiometer is simply a variable resistor.

What should be expected? If I know what to expect I will be able to understand who went wrong and where (probably). Thanks for the help.

If you short circuit the load ( 0 Ω ), the load power will be measured 0 W, as the volt meter will show 0 V ( P = V * I ). Still power will be lost in the generator due to ohmic resistance in the coils, but these losses are internal, so the efficiency will be 0 %.

I vote for the other group.

Fair enough, that makes sense. Any other replies welcome :)

I have to ask another question: The efficiencies found both ours and other group's experiments are very small (<1%) while real steam turbines have much higher efficiencies (according to my googling)...

Would this have to do with the fact that our loads are also tiny, while real turbines would power whole cities?

khometmibro1 said:
Would this have to do with the fact that our loads are also tiny, compared to the generators rated power
( My verbal alteration ).

Yes. In the generator there also are power independant losses such as friction and iron-losses. This means that if the rated power is not made use of, the efficiency will fall.

Understood. Thankyou.

## 1. What is a steam boiler?

A steam boiler is a closed vessel in which water is heated to produce steam. The steam produced is used for various industrial processes or to power steam engines.

## 2. How does a steam boiler work?

A steam boiler works by heating water until it becomes steam. This is typically done by burning fuel, such as coal or gas, in a furnace and then transferring the heat to the water through metal tubes. The steam produced is then used for various applications.

## 3. What is the purpose of a generator in a steam boiler system?

The purpose of a generator in a steam boiler system is to convert the energy of the steam into electricity. This is typically done by rotating a turbine with the steam and then using an electromagnetic generator to convert the mechanical energy into electrical energy.

## 4. What are the different types of steam boilers?

There are several types of steam boilers, including fire-tube boilers, water-tube boilers, and electric boilers. Fire-tube boilers use hot gases from a furnace to heat water in a vessel, while water-tube boilers use heated water to create steam. Electric boilers use electricity to heat the water directly.

## 5. What are the safety precautions to take when operating a steam boiler?

Some important safety precautions to take when operating a steam boiler include regular maintenance and inspections, ensuring proper water levels and pressure, and following proper operating procedures. It is also important to have safety features, such as pressure gauges and safety valves, in place to prevent accidents.

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