Mazda CT-L1005, Руководство по обучению

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Fundamentals Basic Climate Control
Latent Heat
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The following graph shows the amount of heat added to 1 kg of water on the horizontal
axis, and on the vertical axis shows the temperature of the water. In the first stage the
water is frozen, and as heat is added to it, the temperature rises. As soon as the ice
reaches 0 °C it starts to melt. At this point all the heat energy is used to change the ice to
water; this is called the
latent heat of fusion .
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Stage 2 shows that even though the entire energy (334 kJ) is added to the ice/water
mixture, the temperature does not change. Only when all of the ice is melted, does the
temperature start to rise again in direct relation to the amount of heat added (stage 3).
This is because the energy added is no longer required to change the ice to water, and
now the energy being added increases the temperature.
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At 100 °C the water starts to boil. At this point the temperature stops increasing, since all
the energy is needed to change the state from a liquid to a gas. This is known as the
latent heat of vaporization . This physical property is critical to the functioning of the
A/C. Stage 4 shows that the entire energy (2,258 kJ) is absorbed without increasing the
temperature of the water/steam mixture. This is the physical property that allows so
much heat to be taken from the warm air entering the vehicle.
02-6 Curriculum Training