Physics and Chemistry

How to use a fluid to warm or cool?

Heat pump.

I Key words(individual work)

II Basic experiments(presentation by pupils)

Available equipment:

- syringe with flexible pipe- test tube- cloth

- pressure meter- flask of ether- mobile extractor fan

- water- electronic thermometer- gloves and glasses

1) Demonstratethat the change of state temperature depends on the pressure.

Explain what you need, describe what happens and conclude.

2) Highlight the fact that a change of state can involve a heat consumption.

Explain what you need, describe what happens and conclude.

What happens / Conclusion
Experiment 1
Experiment 2

III Operating principle of a heat pump(individual work)

Its principal plan is represented below:

1) What happens to the fluid in the evaporator?

2) Why is a compressor needed?

3) What about the condensor?

4) Compare theelectrical energyrequired to operate thecompressor and theenergy produced as heat. What is the point?

IV Professional simulation(presentation by pupils)

You work ina company that offersmarketingand installation ofheat pumps.

Asa project manager,you need topromotethis type of heatingpresenting itsadvantages over more common andless efficient methods ofheating,from the point ofview of energy.

Your audiencewill appreciatea slideshow thatwill allow you tobrieflyexplainthe principle andthe strengthsof your products.

Make aslideshow(10 pagesmaximum)withyourusualtools. It may bedecorated withphotos,figures andcomparative studies

I Key words(individual work)

II Basic experiments(presentation by 2 pupils)

What happens / Conclusion
Experiment 1 / We introduce abit of warm waterina
syringe.Thesyringe is obstructed with a
finger tip. Graduallypullingthe plunger,
we find that waterboils / It is possible tocause the change ofstate
of a fluidacting on thepressure value.
Experiment 2 / Under thehood:pouringwater ina test
tubecovered witha cloth.An electronic thermometerindicates the temperature
ofthe water.Soak thecloth withether.
Quickly, thewater temperaturedecreases
Finally, theclothis dry. / When fluidpasses from theliquid state to
thegaseous state, ittakesheat from thesurrounding environment.

III Operating principle of a heat pump(individual work)

1) the fluid passesfrom the liquid statetothe gaseous state anddraws energy(heat) from the ground

2) the compressor increasesthe gas pressureandits temperature

3) in the condenser,the fluid passesfrom the gaseoustothe liquid state,which allowsproviding heatfor heating

4) the electrical energyrequired to operatethepump is lower thanthat producedin the form ofheat.

IV Professional simulation: example of video